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Sample records for rate dose brachytherapy

  1. High dose rate brachytherapy for oral cancer.

    Science.gov (United States)

    Yamazaki, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Furukawa, Souhei; Koizumi, Masahiko; Ogawa, Kazuhiko

    2013-01-01

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer.

  2. High dose rate brachytherapy for oral cancer

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Koizumi, Masahiko; Ogawa, Kazuhiko; Furukawa, Souhei

    2013-01-01

    Brachytherapy results in better dose distribution compared with other treatments because of steep dose reduction in the surrounding normal tissues. Excellent local control rates and acceptable side effects have been demonstrated with brachytherapy as a sole treatment modality, a postoperative method, and a method of reirradiation. Low-dose-rate (LDR) brachytherapy has been employed worldwide for its superior outcome. With the advent of technology, high-dose-rate (HDR) brachytherapy has enabled health care providers to avoid radiation exposure. This therapy has been used for treating many types of cancer such as gynecological cancer, breast cancer, and prostate cancer. However, LDR and pulsed-dose-rate interstitial brachytherapies have been mainstays for head and neck cancer. HDR brachytherapy has not become widely used in the radiotherapy community for treating head and neck cancer because of lack of experience and biological concerns. On the other hand, because HDR brachytherapy is less time-consuming, treatment can occasionally be administered on an outpatient basis. For the convenience and safety of patients and medical staff, HDR brachytherapy should be explored. To enhance the role of this therapy in treatment of head and neck lesions, we have reviewed its outcomes with oral cancer, including Phase I/II to Phase III studies, evaluating this technique in terms of safety and efficacy. In particular, our studies have shown that superficial tumors can be treated using a non-invasive mold technique on an outpatient basis without adverse reactions. The next generation of image-guided brachytherapy using HDR has been discussed. In conclusion, although concrete evidence is yet to be produced with a sophisticated study in a reproducible manner, HDR brachytherapy remains an important option for treatment of oral cancer. (author)

  3. High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ghadjar, Pirus, E-mail: pirus.ghadjar@insel.ch [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Bojaxhiu, Beat [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Simcock, Mathew [Swiss Group for Clinical Cancer Research Coordinating Center, Bern (Switzerland); Terribilini, Dario; Isaak, Bernhard [Division of Medical Radiation Physics, Inselspital, Bern University Hospital, and University of Bern, Bern (Switzerland); Gut, Philipp; Wolfensberger, Patrick; Broemme, Jens O.; Geretschlaeger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M. [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland)

    2012-07-15

    Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3-23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

  4. High Dose-Rate Versus Low Dose-Rate Brachytherapy for Lip Cancer

    International Nuclear Information System (INIS)

    Ghadjar, Pirus; Bojaxhiu, Beat; Simcock, Mathew; Terribilini, Dario; Isaak, Bernhard; Gut, Philipp; Wolfensberger, Patrick; Brömme, Jens O.; Geretschläger, Andreas; Behrensmeier, Frank; Pica, Alessia; Aebersold, Daniel M.

    2012-01-01

    Purpose: To analyze the outcome after low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy for lip cancer. Methods and Materials: One hundred and three patients with newly diagnosed squamous cell carcinoma of the lip were treated between March 1985 and June 2009 either by HDR (n = 33) or LDR brachytherapy (n = 70). Sixty-eight patients received brachytherapy alone, and 35 received tumor excision followed by brachytherapy because of positive resection margins. Acute and late toxicity was assessed according to the Common Terminology Criteria for Adverse Events 3.0. Results: Median follow-up was 3.1 years (range, 0.3–23 years). Clinical and pathological variables did not differ significantly between groups. At 5 years, local recurrence-free survival, regional recurrence-free survival, and overall survival rates were 93%, 90%, and 77%. There was no significant difference for these endpoints when HDR was compared with LDR brachytherapy. Forty-two of 103 patients (41%) experienced acute Grade 2 and 57 of 103 patients (55%) experienced acute Grade 3 toxicity. Late Grade 1 toxicity was experienced by 34 of 103 patients (33%), and 5 of 103 patients (5%) experienced late Grade 2 toxicity; no Grade 3 late toxicity was observed. Acute and late toxicity rates were not significantly different between HDR and LDR brachytherapy. Conclusions: As treatment for lip cancer, HDR and LDR brachytherapy have comparable locoregional control and acute and late toxicity rates. HDR brachytherapy for lip cancer seems to be an effective treatment with acceptable toxicity.

  5. Dose rate correction in medium dose rate brachytherapy for carcinoma cervix

    International Nuclear Information System (INIS)

    Patel, F.D.; Negi, P.S.; Sharma, S.C.; Kapoor, R.; Singh, D.P.; Ghoshal, S.

    1998-01-01

    Purpose: To establish the magnitude of brachytherapy dose reduction required for stage IIB and III carcinoma cervix patients treated by external radiation and medium dose rate (MDR) brachytherapy at a dose rate of 220±10 cGy/h at point A.Materials and methods: In study-I, at the time of MDR brachytherapy application at a dose rate of 220±10 cGy/h at point A, patients received either 3060 cGy, a 12.5% dose reduction (MDR-12.5), or 2450 cGy, a 30% dose reduction (MDR-30), to point A and they were compared to a group of previously treated LDR patients who received 3500 cGy to point A at a dose rate of 55-65 cGy/h. Study-II was a prospective randomized trial and patients received either 2450 cGy, a 30% dose reduction (MDR-II (30)) or 2800 cGy, a 20% dose reduction (MDR-II (20)), at point A. Patients were evaluated for local control of disease and morbidity. Results: In study-I the 5-year actuarial local control rate in the MDR-30 and MDR-12.5 groups was 71.7±10% and 70.5±10%, respectively, compared to 63.4±10% in the LDR group. However, the actuarial morbidity (all grades) in the MDR-12.5 group was 58.5±14% as against 34.9±9% in the LDR group (P 3 developed complication as against 62.5% of those receiving a rectal BED of (140 3 (χ 2 =46.43; P<0.001). Conclusion: We suggest that at a dose rate of 220±10 cGy/h at point A the brachytherapy dose reduction factor should be around 30%, as suggested by radiobiological data, to keep the morbidity as low as possible without compromising the local control rates. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  6. Biology of dose rate in brachytherapy

    International Nuclear Information System (INIS)

    Brenner, David J.

    1995-01-01

    Purpose: This course is designed for practitioners and beginners in brachytherapy. The aim is to review biological principles underlying brachytherapy, to understand why current treatment regimes are the way they are, and to discuss what the future may hold in store. Brachytherapy has a long history. It was suggested as long ago as 1903 by Alexander Graham Bell, and the optimal application of this technique has been a subject of debate ever since. 'Brachy' means 'short', and the essential features of conventional brachytherapy are: positioning of the source a short distance from, or in, the tumor, allowing good dose distributions; short overall treatment times, to counter tumor repopulation; low dose rate, enabling a good therapeutic advantage between tumor control and damage to late-responding tissue. The advantages of good dose distributions speak for themselves; in some situations, as we shall see, computer-based dose optimization can be used to improve them still further. The advantages of short overall times stem from the fact that accelerated repopulation of the tumor typically begins a few weeks after the start of a radiation treatment. If all the radiation can be crammed in before that time, the risks of tumor repopulation can be considerably reduced. In fact even external-beam radiotherapy is moving in this direction, with the use of highly accelerated protocols. The advantages of low dose rate stem from the differential response to fractionation of early- and late-responding tissues. Essentially, lowering the dose rate spares late-responding tissue more than it does early-responding tissue such as tumors. We shall also discuss some recent innovations in the context of the general principles that have been outlined. For example, High dose rate brachytherapy, particularly for the uterine cervix: Does it work? If so, when and why? Use of Ir-192 sources, with a half life of 70 days: Should corrections be made for changing biological effectiveness as the dose

  7. Brachytherapy for early oral tongue cancer. Low dose rate to high dose rate

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Inoue, Takehiro; Yoshida, Ken; Yoshioka, Yasuo; Shimizutani, Kimishige; Inoue, Toshihiko; Furukawa, Souhei; Kakimoto, Naoya

    2003-01-01

    To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n=341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer. (author)

  8. The American Brachytherapy Society recommendations for low-dose-rate brachytherapy for carcinoma of the cervix

    International Nuclear Information System (INIS)

    Nag, Subir; Chao, Clifford; Erickson, Beth; Fowler, Jeffery; Gupta, Nilendu; Martinez, Alvaro; Thomadsen, Bruce

    2002-01-01

    Purpose: This report presents guidelines for using low-dose-rate (LDR) brachytherapy in the management of patients with cervical cancer. Methods: Members of the American Brachytherapy Society (ABS) with expertise in LDR brachytherapy for cervical cancer performed a literature review, supplemented by their clinical experience, to formulate guidelines for LDR brachytherapy of cervical cancer. Results: The ABS strongly recommends that radiation treatment for cervical carcinoma (with or without chemotherapy) should include brachytherapy as a component. Precise applicator placement is essential for improved local control and reduced morbidity. The outcome of brachytherapy depends, in part, on the skill of the brachytherapist. Doses given by external beam radiotherapy and brachytherapy depend upon the initial volume of disease, the ability to displace the bladder and rectum, the degree of tumor regression during pelvic irradiation, and institutional practice. The ABS recognizes that intracavitary brachytherapy is the standard technique for brachytherapy for cervical carcinoma. Interstitial brachytherapy should be considered for patients with disease that cannot be optimally encompassed by intracavitary brachytherapy. The ABS recommends completion of treatment within 8 weeks, when possible. Prolonging total treatment duration can adversely affect local control and survival. Recommendations are made for definitive and postoperative therapy after hysterectomy. Although recognizing that many efficacious LDR dose schedules exist, the ABS presents suggested dose and fractionation schemes for combining external beam radiotherapy with LDR brachytherapy for each stage of disease. The dose prescription point (point A) is defined for intracavitary insertions. Dose rates of 0.50 to 0.65 Gy/h are suggested for intracavitary brachytherapy. Dose rates of 0.50 to 0.70 Gy/h to the periphery of the implant are suggested for interstitial implant. Use of differential source activity or

  9. Radiobiological modelling of dose-gradient effects in low dose rate, high dose rate and pulsed brachytherapy

    International Nuclear Information System (INIS)

    Armpilia, C; Dale, R G; Sandilos, P; Vlachos, L

    2006-01-01

    This paper presents a generalization of a previously published methodology which quantified the radiobiological consequences of dose-gradient effects in brachytherapy applications. The methodology uses the linear-quadratic (LQ) formulation to identify an equivalent biologically effective dose (BED eq ) which, if applied uniformly to a specified tissue volume, would produce the same net cell survival as that achieved by a given non-uniform brachytherapy application. Multiplying factors (MFs), which enable the equivalent BED for an enclosed volume to be estimated from the BED calculated at the dose reference surface, have been calculated and tabulated for both spherical and cylindrical geometries. The main types of brachytherapy (high dose rate (HDR), low dose rate (LDR) and pulsed (PB)) have been examined for a range of radiobiological parameters/dimensions. Equivalent BEDs are consistently higher than the BEDs calculated at the reference surface by an amount which depends on the treatment prescription (magnitude of the prescribed dose) at the reference point. MFs are closely related to the numerical BED values, irrespective of how the original BED was attained (e.g., via HDR, LDR or PB). Thus, an average MF can be used for a given prescribed BED as it will be largely independent of the assumed radiobiological parameters (radiosensitivity and α/β) and standardized look-up tables may be applicable to all types of brachytherapy treatment. This analysis opens the way to more systematic approaches for correlating physical and biological effects in several types of brachytherapy and for the improved quantitative assessment and ranking of clinical treatments which involve a brachytherapy component

  10. Pulsed dose rate and fractionated high dose rate brachytherapy: choice of brachytherapy schedules to replace low dose rate treatments

    International Nuclear Information System (INIS)

    Visser, Andries G.; Aardweg, Gerard J.M.J. van den; Levendag, Peter C.

    1996-01-01

    Purpose: Pulsed dose rate (PDR) brachytherapy is a new type of afterloading brachytherapy (BT) in which a continuous low dose rate (LDR) treatment is simulated by a series of 'pulses,' i.e., fractions of short duration (less than 0.5 h) with intervals between fractions of 1 to a few hours. At the Dr. Daniel den Hoed Cancer Center, the term 'PDR brachytherapy' is used for treatment schedules with a large number of fractions (at least four per day), while the term 'fractionated high dose rate (HDR) brachytherapy' is used for treatment schedules with just one or two brachytherapy fractions per day. Both treatments can be applied as alternatives for LDR BT. This article deals with the choice between PDR and fractionated HDR schedules and proposes possible fractionation schedules. Methods and Materials: To calculate HDR and PDR fractionation schedules with the intention of being equivalent to LDR BT, the linear-quadratic (LQ) model has been used in an incomplete repair formulation as given by Brenner and Hall, and by Thames. In contrast to earlier applications of this model, both the total physical dose and the overall time were not kept identical for LDR and HDR/PDR schedules. A range of possible PDR treatment schedules is presented, both for booster applications (in combination with external radiotherapy (ERT) and for BT applications as a single treatment. Because the knowledge of both α/β values and the half time for repair of sublethal damage (T (1(2)) ), which are required for these calculations, is quite limited, calculations regarding the equivalence of LDR and PDR treatments have been performed for a wide range of values of α/β and T (1(2)) . The results are presented graphically as PDR/LDR dose ratios and as ratios of the PDR/LDR tumor control probabilities. Results: If the condition that total physical dose and overall time of a PDR treatment must be exactly identical to the values for the corresponding LDR treatment regimen is not applied, there appears

  11. Quality control of 192Ir high dose rate after loading brachytherapy dose veracity

    International Nuclear Information System (INIS)

    Feng Zhongsu; Xu Xiao; Liu Fen

    2008-01-01

    Recently, 192 Ir high dose rate (HDR) afterloading are widely used in brachytherapy. The advantage of using HDR systems over low dose rate systems are shorter treatment time and higher fraction dose. To guarantee the veracity of the delivery dose, several quality control methods are deseribed in this work. With these we can improve the position precision, time precision and dose precision of the brachytherapy. (authors)

  12. Brachytherapy for cervix cancer: low-dose rate or high-dose rate brachytherapy – a meta-analysis of clinical trials

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    Stefano Eduardo J

    2009-04-01

    Full Text Available Abstract Background The literature supporting high-dose rate brachytherapy (HDR in the treatment of cervical carcinoma derives primarily from retrospective series. However, controversy still persists regarding the efficacy and safety of HDR brachytherapy compared to low-dose rate (LDR brachytherapy, in particular, due to inadequate tumor coverage for stage III patients. Whether LDR or HDR brachytherapy produces better results for these patients in terms of survival rate, local control rate and the treatment complications remain controversial. Methods A meta-analysis of RCT was performed comparing LDR to HDR brachytherapy for cervix cancer treated for radiotherapy alone. The MEDLINE, EMBASE, CANCERLIT and Cochrane Library databases, as well as abstracts published in the annual proceedings were systematically searched. We assessed methodological quality for each outcome by grading the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE methodology. We used "recommend" for strong recommendations, and "suggest" for weak recommendations. Results Pooled results from five randomized trials (2,065 patients of HDR brachytherapy in cervix cancer showed no significant increase of mortality (p = 0.52, local recurrence (p = 0.68, or late complications (rectal; p = 0.7, bladder; p = 0.95 or small intestine; p = 0.06 rates as compared to LDR brachytherapy. In the subgroup analysis no difference was observed for overall mortality and local recurrence in patients with clinical stages I, II and III. The quality of evidence was low for mortality and local recurrence in patients with clinical stage I, and moderate for other clinical stages. Conclusion Our meta-analysis shows that there are no differences between HDR and LDR for overall survival, local recurrence and late complications for clinical stages I, II and III. By means of the GRADE system, we recommend the use of HDR for all clinical stages of cervix

  13. Brachytherapy for cervix cancer: low-dose rate or high-dose rate brachytherapy – a meta-analysis of clinical trials

    Science.gov (United States)

    Viani, Gustavo A; Manta, Gustavo B; Stefano, Eduardo J; de Fendi, Ligia I

    2009-01-01

    Background The literature supporting high-dose rate brachytherapy (HDR) in the treatment of cervical carcinoma derives primarily from retrospective series. However, controversy still persists regarding the efficacy and safety of HDR brachytherapy compared to low-dose rate (LDR) brachytherapy, in particular, due to inadequate tumor coverage for stage III patients. Whether LDR or HDR brachytherapy produces better results for these patients in terms of survival rate, local control rate and the treatment complications remain controversial. Methods A meta-analysis of RCT was performed comparing LDR to HDR brachytherapy for cervix cancer treated for radiotherapy alone. The MEDLINE, EMBASE, CANCERLIT and Cochrane Library databases, as well as abstracts published in the annual proceedings were systematically searched. We assessed methodological quality for each outcome by grading the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. We used "recommend" for strong recommendations, and "suggest" for weak recommendations. Results Pooled results from five randomized trials (2,065 patients) of HDR brachytherapy in cervix cancer showed no significant increase of mortality (p = 0.52), local recurrence (p = 0.68), or late complications (rectal; p = 0.7, bladder; p = 0.95 or small intestine; p = 0.06) rates as compared to LDR brachytherapy. In the subgroup analysis no difference was observed for overall mortality and local recurrence in patients with clinical stages I, II and III. The quality of evidence was low for mortality and local recurrence in patients with clinical stage I, and moderate for other clinical stages. Conclusion Our meta-analysis shows that there are no differences between HDR and LDR for overall survival, local recurrence and late complications for clinical stages I, II and III. By means of the GRADE system, we recommend the use of HDR for all clinical stages of cervix cancer. PMID:19344527

  14. Low dose rate Ir-192 interstitial brachytherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Oki, Yosuke; Dokiya, Takushi; Yorozu, Atsunori; Suzuki, Takayuki; Saito, Shiro; Monma, Tetsuo; Ohki, Takahiro [National Tokyo Medical Center (Japan); Murai, Masaru; Kubo, Atsushi

    2000-04-01

    From December 1997 through January 1999, fifteen prostatic cancer patients were treated with low dose rate Ir-192 interstitial brachytherapy using TRUS and perineal template guidance without external radiotherapy. Up to now, as no apparent side effects were found, the safety of this treatment is suggested. In the future, in order to treat prostatic cancer patients with interstitial brachytherapy using I-125 or Pd-103, more investigation for this low dose rate Ir-192 interstitial brachytherapy is needed. (author)

  15. Braquiterapia de alta taxa de dose no Brasil High-dose rate brachytherapy in Brazil

    Directory of Open Access Journals (Sweden)

    Sérgio Carlos Barros Esteves

    2004-10-01

    Full Text Available A braquiterapia de alta taxa de dose foi introduzida em nosso meio em janeiro de 1991. Desde então, houve uma mudança significativa na abordagem das neoplasias malignas em relação às vantagens do novo método, e também resolução da demanda reprimida de braquiterapia para as neoplasias ginecológicas. Nos primeiros dez anos de atividade, o Brasil tratou, em 31 serviços, 26.436 pacientes com braquiterapia, sendo mais de 50% das pacientes portadoras de neoplasias do colo uterino. Este estudo mostra o número e o perfil de pacientes tratados com esse método e a sua distribuição no território nacional, deixando explícito o benefício da braquiterapia de alta taxa de dose para o Brasil.High-dose rate brachytherapy was first introduced in Brazil in January 1991. Significant changes in the management of malignant neoplasms were observed since utilization of high-dose rate brachytherapy. The high number of gynecological patients awaiting for brachytherapy also decreased during this period. In the first ten years 26,436 patients were treated with high-dose rate brachytherapy. More than 50% of these patients presented neoplasms of the uterine cervix. In this study we present the number and profile of the patients treated with high-dose rate brachytherapy as well as the distribution of these patients in the Brazilian territory, proving the benefit of the use of high-dose rate brachytherapy in Brazil.

  16. Endorectal high dose rate brachytherapy quality assurance

    International Nuclear Information System (INIS)

    Devic, S.; Vuong, T.; Evans, M.; Podgorsak, E.

    2008-01-01

    We describe our quality assurance method for preoperative high dose rate (HDR) brachytherapy of endorectal tumours. Reproduction of the treatment planning dose distribution on a daily basis is crucial for treatment success. Due to the cylindrical symmetry, two types of adjustments are necessary: applicator rotation and dose distribution shift along the applicator axis. (author)

  17. Concomitant chemoradiotherapy with high dose rate brachytherapy ...

    African Journals Online (AJOL)

    Concomitant chemoradiotherapy with high dose rate brachytherapy as a definitive treatment modality for locally advanced cervical cancer. T Refaat, A Elsaid, N Lotfy, K Kiel, W Small Jr, P Nickers, E Lartigau ...

  18. Cost minimization analysis of high-dose-rate versus low-dose-rate brachytherapy in endometrial cancer

    International Nuclear Information System (INIS)

    Pinilla, James

    1998-01-01

    Purpose: Endometrial cancer is a common, usually curable malignancy whose treatment frequently involves low-dose-rate (LDR) or high-dose-rate (HDR) brachytherapy. These treatments involve substantial resource commitments and this is increasingly important. This paper presents a cost minimization analysis of HDR versus LDR brachytherapy in the treatment of endometrial cancer. Methods and Materials: The perspective of the analysis is that of the payor, in this case the Ministry of Health. One course of LDR treatment is compared to two courses of HDR treatment. The two alternatives are considered to be comparable with respect to local control, survival, and toxicities. Labor, overhead, and capital costs are accounted for and carefully measured. A 5% inflation rate is used where applicable. A univariate sensitivity analysis is performed. Results: The HDR regime is 22% less expensive compared to the LDR regime. This is $991.66 per patient or, based on the current workload of this department (30 patients per year) over the useful lifetime of the after loader, $297,498 over 10 years in 1997 dollars. Conclusion: HDR brachytherapy minimizes costs in the treatment of endometrial cancer relative to LDR brachytherapy. These results may be used by other centers to make rational decisions regarding brachytherapy equipment replacement or acquisition

  19. High-dose-rate brachytherapy alone post-hysterectomy for endometrial cancer

    International Nuclear Information System (INIS)

    MacLeod, Craig; Fowler, Allan; Duval, Peter; D'Costa, Ieta; Dalrymple, Chris; Firth, Ian; Elliott, Peter; Atkinson, Ken; Carter, Jonathan

    1998-01-01

    Purpose: To evaluate the outcome of post-hysterectomy adjuvant vaginal high-dose-rate (HDR) brachytherapy. Methods and Materials: A retrospective analysis was performed on a series of 143 patients with endometrial cancer treated with HDR brachytherapy alone post-hysterectomy from 1985 to June 1993. Of these patients, 141 received 34 Gy in four fractions prescribed to the vaginal mucosa in a 2-week period. The median follow-up was 6.9 years. Patients were analyzed for treatment parameters, survival, local recurrence, distant relapse, and toxicity. Results: Five-year relapse free survival and overall survival was 100% and 88% for Stage 1A, 98% and 94% for Stage IB, 100% and 86% for Stage IC, and 92% and 92% for Stage IIA. The overall vaginal recurrence rate was 1.4%. The overall late-toxicity rate was low, and no RTOG grade 3, 4, or 5 complications were recorded. Conclusion: These results are similar to reported international series that have used either low-dose-rate or HDR brachytherapy. The biological effective dose was low for both acute and late responding tissues compared with some of the HDR brachytherapy series, and supports using this lower dose and possibly decreasing late side-effects with no apparent increased risk of vaginal recurrence

  20. Physics and quality assurance for brachytherapy - Part II: Low dose rate and pulsed dose rate

    International Nuclear Information System (INIS)

    Williamson, Jeffrey F.

    1997-01-01

    Purpose: A number of recent developments have revitalized brachytherapy including remote afterloading, implant optimization, increasing use of 3D imaging, and advances in dose specification and basic dosimetry. However, the core physical principles underlying the classical methods of dose calculation and arrangement of multiple sources remain unchanged. The purpose of this course is to review these principles and their applications to low dose-rate interstitial and intracavitary brachytherapy. Emphasis will be placed upon the classical implant systems along with classical and modern methods of dose specification. The level of presentation is designed for radiation oncology residents and beginning clinical physicists. A. Basic Principles (1) Radium-substitute vs. low-energy sealed sources (2) Dose calculation principles (3) The mysteries of source strength specification revealed: mgRaEq, mCi and air-kerma strength B. Interstitial Brachytherapy (1) Target volume, implanted volume, dose specification in implants and implant optimization criteria (2) Classical implant systems: Manchester Quimby and Paris a) Application of the Manchester system to modern brachytherapy b) Comparison of classical systems (3) Permanent interstitial implants a) Photon energy and half life b) Dose specification and pre-operative planning (4) The alphabet soup of dose specification: MCD (mean central dose), minimum dose, MPD (matched peripheral dose), MPD' (minimum peripheral dose) and DVH (dose-volume histogram) quality indices C. Intracavitary Brachytherapy for Carcinoma of the Cervix (1) Basic principles a) Manchester System: historical foundation of U.S. practice patterns b) Principles of applicator design (2) Dose specification and treatment prescription a) mg-hrs, reference points, ICRU Report 38 reference volume -- Point A dose vs mg-hrs and IRAK (Integrated Reference Air Kerma) -- Tissue volume treated vs mg-hrs and IRAK b) Practical methods of treatment specification and prescription

  1. Physics and quality assurance for brachytherapy - Part II: Low dose rate and pulsed dose rate

    International Nuclear Information System (INIS)

    Williamson, Jeffrey F.

    1996-01-01

    Purpose: A number of recent developments have revitalized brachytherapy including remote afterloading, implant optimization, increasing use of 3D imaging, and advances in dose specification and basic dosimetry. However, the core physical principles underlying the classical methods of dose calculation and arrangement of multiple sources remain unchanged. The purpose of this course is to review these principles and their applications to low dose-rate interstitial and intracavitary brachytherapy. Emphasis will be placed upon the classical implant systems along with classical and modern methods of dose specification. The level of presentation is designed for radiation oncology residents and beginning clinical physicists. A. Basic Principles (1) Radium-substitute vs. low-energy sealed sources (2) Dose calculation principles (3) The mysteries of source strength specification revealed: mgRaEq, mCi and air-kerma strength B. Interstitial Brachytherapy (1) Target volume, implanted volume, dose specification in implants and implant optimization criteria (2) Classical implant systems: Manchester Quimby and Paris a) Application of the Manchester system to modern brachytherapy b) Comparison of classical systems (3) Permanent interstitial implants a) Photon energy and half life b) Dose specification and pre-operative planning (4) The alphabet soup of dose specification: MCD (mean central dose), minimum dose, MPD (matched peripheral dose), MPD' (minimum peripheral dose) and DVH (dose-volume histogram) quality indices C. Intracavitary Brachytherapy for Carcinoma of the Cervix (1) Basic principles a) Manchester System: historical foundation of U.S. practice patterns b) Principles of applicator design (2) Dose specification and treatment prescription a) mg-hrs, reference points, ICRU Report 38 reference volume --Point A dose vs mg-hrs and IRAK (Integrated Reference Air Kerma) --Tissue volume treated vs mg-hrs and IRAK b) Practical methods of treatment specification and prescription

  2. Interstitial high-dose rate brachytherapy as boost for anal canal cancer

    International Nuclear Information System (INIS)

    Falk, Alexander Tuan; Claren, Audrey; Benezery, Karen; François, Eric; Gautier, Mathieu; Gerard, Jean-Pierre; Hannoun-Levi, Jean-Michel

    2014-01-01

    To assess clinical outcomes of patients treated with a high-dose rate brachytherapy boost for anal canal cancer (ACC). From August 2005 to February 2013, 28 patients presenting an ACC treated by split-course external beam radiotherapy (EBRT) and HDR brachytherapy with or without chemotherapy in a French regional cancer center in Nice were retrospectively analyzed. Median age was 60.6 years [34 – 83], 25 patients presented a squamous cell carcinoma and 3 an adenocarcinoma; 21 received chemotherapy. Median dose of EBRT was 45 Gy [43.2 – 52]. Median dose of HDR brachytherapy was 12 Gy [10 - 15] with a median duration of 2 days. Median overall treatment time was 63 days and median delay between EBRT and brachytherapy was 20 days. Two-year local relapse free, metastatic free, disease free and overall survivals were 83%, 81.9%, 71.8% and 87.7% respectively. Acute toxicities were frequent but not severe with mostly grade 1 toxicities: 37% of genito-urinary, 40.7% of gastro-intestinal and 3.7% of cutaneous toxicities. Late toxicities were mainly G1 (43.1%) and G2 (22%). Two-year colostomy-free survival was 75.1%, one patient had a definitive sphincter amputation. High-dose rate brachytherapy for anal canal carcinoma as boost represents a feasible technique compared to low or pulsed-dose rate brachytherapy. This technique remains an excellent approach to precisely boost the tumor in reducing the overall treatment time

  3. High-dose-rate interstitial brachytherapy for the treatment of penile carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Petera, J.; Odrazka, K.; Zouhar, M.; Bedrosova, J.; Dolezel, M. [Dept. of Oncology and Radiotherapy, Charles Univ. Medical School and Teaching Hospital, Hradec Kralove (Czech Republic)

    2004-02-01

    Background: interstitial low-dose-rate (LDR) brachytherapy allows conservative treatment of T1-T2 penile carcinoma. High-dose-rate (HDR) is often considered to be dangerous for interstitial implants because of a higher risk of complications, but numerous reports suggest that results may be comparable to LDR. Nevertheless, there are no data in the literature available regarding HDR interstitial brachytherapy for carcinoma of the penis. Case report: a 64-year-old man with T1 NO MO epidermoid carcinoma of the glans is reported. Interstitial HDR brachytherapy was performed using the stainless hollow needle technique and a breast template for fixation and good geometry. The dose delivered was 18 x 3 Gy twice daily. Results: after 232 days from brachytherapy, the patient was without any evidence of the tumor, experienced no serious radiation-induced complications, and had a fully functional organ. Conclusion: HDR interstitial brachytherapy is feasible in selected case of penis carcinoma, when careful planning and small single fractions are used. (orig.)

  4. HIGH-DOSE RATE BRACHYTHERAPY IN CARCINOMA CERVIX STAGE IIIB

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    Sathya Maruthavanan

    2016-07-01

    Full Text Available INTRODUCTION Radiotherapy is the standard treatment in locally advanced (IIB-IVA and early inoperable cases. The current standard of practice with curable intent is concurrent chemoradiation in which intracavitary brachytherapy is an integral component of radiotherapy. This study aims at assessing the efficacy of HDR ICBT (High-dose rate intracavitary brachytherapy in terms local response, normal tissue reactions, and feasibility. METHODS AND MATERIALS A total of 20 patients of stage IIIB cancer of the uterine cervix were enrolled in the study and were planned to receive concurrent chemotherapy weekly along with EBRT (external beam radiotherapy to a dose of 50 Gy/25 Fr. Suitability for ICBT was assessed at 40 Gy/20 Fr. 6/20 patients were suitable at 40 Gy and received HDR ICBT with a dose of 5.5 Gy to point A in 4 sessions (5.5 Gy/4 Fr. The remaining 14/20 patients completed 50 Gy and received HDR ICBT with a dose of 6 Gy to point A in 3 sessions (6 Gy/3 Fr. RESULTS A total of 66 intracavitary applications were done and only one application required dose modification due to high bladder dose, the pelvic control rate was 85% (17/20. 10% (2/20 had stable disease and 5% (1/20 had progressive disease at one year of follow up. When toxicity was considered only 15% developed grade I and grade II rectal complications. Patient compliance and acceptability was 100%. Patients were very comfortable with the short treatment time as compared with patients on LDR ICBT (low-dose rate intracavitary brachytherapy treatment interviewed during the same period. CONCLUSION This study proves that HDR brachytherapy is efficacious and feasible in carcinoma of cervix stage IIIB. It also proves that good dose distribution can be achieved with HDR intracavitary facility by the use of dose optimization. The short treatment time in HDR ICBT makes it possible to maintain this optimised dose distribution throughout the treatment providing a gain in the therapeutic ratio and

  5. Developing A Directional High-Dose Rate (d-HDR) Brachytherapy Source

    Science.gov (United States)

    Heredia, Athena Yvonne

    Conventional sources used in brachytherapy provide nearly isotropic or radially symmetric dose distributions. Optimizations of dose distributions have been limited to varied dwell times at specified locations within a given treatment volume, or manipulations in source position for seed implantation techniques. In years past, intensity modulated brachytherapy (IMBT) has been used to reduce the amount of radiation to surrounding sensitive structures in select intracavitary cases by adding space or partial shields. Previous work done by Lin et al., at the University of Wisconsin-Madison, has shown potential improvements in conformality for brachytherapy treatments using a directionally shielded low dose rate (LDR) source for treatments in breast and prostate. Directional brachytherapy sources irradiate approximately half of the radial angles around the source, and adequately shield a quarter of the radial angles on the opposite side, with sharp gradient zones between the treated half and shielded quarter. With internally shielded sources, the radiation can be preferentially emitted in such a way as to reduce toxicities in surrounding critical organs. The objective of this work is to present findings obtained in the development of a new directional high dose rate (d-HDR) source. To this goal, 103Pd (Z = 46) is reintroduced as a potential radionuclide for use in HDR brachytherapy. 103Pd has a low average photon energy (21 keV) and relatively short half -life (17 days), which is why it has historically been used in low dose rate applications and implantation techniques. Pd-103 has a carrier-free specific activity of 75000 Ci/g. Using cyclotron produced 103Pd, near carrier-free specific activities can be achieved, providing suitability for high dose rate applications. The evolution of the d-HDR source using Monte Carlo simulations is presented, along with dosimetric parameters used to fully characterize the source. In addition, a discussion on how to obtain elemental

  6. Results in patients treated with high-dose-rate interstitial brachytherapy for oral tongue cancer

    International Nuclear Information System (INIS)

    Yamamoto, Michinori; Shirane, Makoto; Ueda, Tsutomu; Miyahara, Nobuyuki

    2006-01-01

    Eight patients were treated with high-dose-rate interstitial brachytherapy for oral tongue cancer between September 2000 and August 2004. The patient distribution was 1 T1, 5 T2, 1 T3, and 1 T4a. Patients received 50-60 Gy in 10 fractions over seven days with high-dose-rate brachytherapy. Six of the eight patients were treated with a combination of external beam radiotherapy (20-30 Gy) and interstitial brachytherapy. The two-year primary local control rate was 83% for initial case. High-dose-rate brachytherapy was performed safely even for an aged person, and was a useful treatment modality for oral tongue cancer. (author)

  7. Rectal dose assessment in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer

    International Nuclear Information System (INIS)

    Oliveira, Jetro Pereira de; Batista, Delano Valdivino Santos; Bardella, Lucia Helena; Carvalho, Arnaldo Rangel

    2009-01-01

    Objective: The present study was aimed at developing a thermoluminescent dosimetric system capable of assessing the doses delivered to the rectum of patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. Materials and methods: LiF:Mg,Ti,Na powder was the thermoluminescent material utilized for evaluating the rectal dose. The powder was divided into small portions (34 mg) which were accommodated in a capillary tube. This tube was placed into a rectal probe that was introduced into the patient's rectum. Results: The doses delivered to the rectum of six patients submitted to high-dose-rate brachytherapy for uterine cervix cancer evaluated by means of thermoluminescent dosimeters presented a good agreement with the planned values based on two orthogonal (anteroposterior and lateral) radiographic images of the patients. Conclusion: The thermoluminescent dosimetric system developed in the present study is simple and easy to be utilized as compared to other rectal dosimetry methods. The system has shown to be effective in the evaluation of rectal doses in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. (author)

  8. Retrospective Dosimetric Comparison of Low-Dose-Rate and Pulsed-Dose-Rate Intracavitary Brachytherapy Using a Tandem and Mini-Ovoids

    International Nuclear Information System (INIS)

    Mourtada, Firas; Gifford, Kent A.; Berner, Paula A.; Horton, John L.; Price, Michael J.; Lawyer, Ann A.; Eifel, Patricia J.

    2007-01-01

    The purpose of this study was to compare the dose distribution of Iridium-192 ( 192 Ir) pulsed-dose-rate (PDR) brachytherapy to that of Cesium-137 ( 137 Cs) low-dose-rate (LDR) brachytherapy around mini-ovoids and an intrauterine tandem. Ten patient treatment plans were selected from our clinical database, all of which used mini-ovoids and an intrauterine tandem. A commercial treatment planning system using AAPM TG43 formalism was used to calculate the dose in water for both the 137 Cs and 192 Ir sources. For equivalent system loadings, we compared the dose distributions in relevant clinical planes, points A and B, and to the ICRU bladder and rectal reference points. The mean PDR doses to points A and B were 3% ± 1% and 6% ± 1% higher than the LDR doses, respectively. For the rectum point, the PDR dose was 4% ± 3% lower than the LDR dose, mainly because of the 192 Ir PDR source anisotropy. For the bladder point, the PDR dose was 1% ± 4% higher than the LDR dose. We conclude that the PDR and LDR dose distributions are equivalent for intracavitary brachytherapy with a tandem and mini-ovoids. These findings will aid in the transfer from the current practice of LDR intracavitary brachytherapy to PDR for the treatment of gynecologic cancers

  9. Pulsed dose rate brachytherapy – is it the right way?

    Directory of Open Access Journals (Sweden)

    Janusz Skowronek

    2010-10-01

    Full Text Available Pulsed dose rate (PDR-BT treatment is a brachytherapy modality that combines physical advantages of high-doserate (HDR-BT technology (isodose optimization, radiation safety with the radiobiological advantages of low-dose-rate (LDR-BT brachytherapy. Pulsed brachytherapy consists of using stronger radiation source than for LDR-BT and producing series of short exposures of 10 to 30 minutes in every hour to approximately the same total dose in the sameoverall time as with the LDR-BT. Modern afterloading equipment offers certain advantages over interstitial or intracavitaryinsertion of separate needles, tubes, seeds or wires. Isodose volumes in tissues can be created flexibly by a combinationof careful placement of the catheter and the adjustment of the dwell times of the computerized stepping source.Automatic removal of the radiation sources into a shielded safe eliminates radiation exposures to staff and visitors.Radiation exposure is also eliminated to the staff who formerly loaded and unloaded multiplicity of radioactive sources into the catheters, ovoids, tubes etc. This review based on summarized clinical investigations, analyses the feasibility and the background to introduce this brachytherapy technique and chosen clinical applications of PDR-BT.

  10. Gynecological brachytherapy - from low-dose-rate to high-tech. Gynaekologische Brachytherapie - von Low-dose-rate zu High-tech

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, T. (Abt. Strahlenthgerapie, Klinik und Poliklinik fuer Radiologie, Medizinische Akademie ' Carl Gustav Carus' , Dresden (Germany)); Christen, N. (Abt. Strahlenthgerapie, Klinik und Poliklinik fuer Radiologie, Medizinische Akademie ' Carl Gustav Carus' , Dresden (Germany)); Alheit, H.D. (Abt. Strahlenthgerapie, Klinik und Poliklinik fuer Radiologie, Medizinische Akademie ' Carl Gustav Carus' , Dresden (Germany))

    1993-03-01

    The transition from low-dose-rate (LDR) brachytherapy to high-dose-rate (HDR) afterloading treatment is in progress in most centres of radiation therapy. First reports of studies comparing HDR and LDR treatment in cervix cancer demonstrate nearly equal local control. In our own investigations on 319 patients with primary irradiated carcinoma of the cervix (125 HDR/194 LDR) we found the following control rates: Stage FIGO I 95.4%/82.9% (HDR versus LDR), stage FIGO II 71.4%/73.7%, stage FIGO III 57.9%/38.5%. The results are not significant. The side effects - scored after EORT/RTOG criteria - showed no significant differences between both therapies for serious radiogenic late effects on intestine, bladder and vagina. The study and findings from the literature confirm the advantage of the HDR-procedure for patient and radiooncologist and for radiation protection showing at least the same results as in the LDR-area. As for radiobiolgical point of view it is important to consider that the use of fractionation in the HDR-treatment is essential for the sparing of normal tissues and therefore a greater number of small fractionation doses in the brachytherapy should be desirable too. On the other hand the rules, which are true for fractionated percutaneous irradiation therapy (overall treatment time as short as possible to avoid reppopulation of tumor cells) should be taken into consideration in combined brachy-teletherapy regime in gynecologic tumors. The first step in this direction may be accelerated regime with a daily application of both treatment procedures. The central blocking of the brachytherapy region from the whole percutaneous treatment target volume should be critically reflected, especially in the case of advanced tumors. (orig.)

  11. High dose rate brachytherapy for superficial cancer of the esophagus

    International Nuclear Information System (INIS)

    Maingon, Philippe; D'Hombres, Anne; Truc, Gilles; Barillot, Isabelle; Michiels, Christophe; Bedenne, Laurent; Horiot, Jean Claude

    2000-01-01

    Purpose: We analyzed our experience with external radiotherapy, combined modality treatment, or HDR brachytherapy alone to limited esophageal cancers. Methods and Materials: From 1991 to 1996, 25 patients with limited superficial esophagus carcinomas were treated by high dose rate brachytherapy. The mean age was 63 years (43-86 years). Five patients showed superficial local recurrence after external radiotherapy. Eleven patients without invasion of the basal membrane were staged as Tis. Fourteen patients with tumors involving the submucosa without spreading to the muscle were staged as T1. Treatment consisted of HDR brachytherapy alone in 13 patients, external radiotherapy and brachytherapy in 8 cases, and concomitant chemo- and radiotherapy in 4 cases. External beam radiation was administered to a total dose of 50 Gy using 2 Gy daily fractions in 5 weeks. In cases of HDR brachytherapy alone (13 patients), 6 applications were performed once a week. Results: The mean follow-up is 31 months (range 24-96 months). Twelve patients received 2 applications and 13 patients received 6 applications. Twelve patients experienced a failure (48%), 11/12 located in the esophagus, all of them in the treated volume. One patient presented an isolated distant metastasis. In the patients treated for superficial recurrence, 4/5 were locally controlled (80%) by brachytherapy alone. After brachytherapy alone, 8/13 patients were controlled (61%). The mean disease-free survival is 14 months (1-36 months). Overall survival is 76% at 1 year, 37% at 2 years, and 14% at 3 years. Overall survival for Tis patients is 24% vs. 20% for T1 (p 0.83). Overall survival for patients treated by HDR brachytherapy alone is 43%. One patient presented with a fistula with local failure after external radiotherapy and brachytherapy. Four stenosis were registered, two were diagnosed on barium swallowing without symptoms, and two required dilatations. Conclusion: High dose rate brachytherapy permits the treating

  12. Focal low-dose rate brachytherapy for the treatment of prostate cancer

    Directory of Open Access Journals (Sweden)

    Tong WY

    2013-09-01

    Full Text Available William Y Tong, Gilad Cohen, Yoshiya Yamada Memorial Sloan-Kettering Cancer Center, Department of Radiation Oncology, New York, NY, USA Abstract: Whole-gland low-dose rate (LDR brachytherapy has been a well-established modality of treating low-risk prostate cancer. Treatment in a focal manner has the advantages of reduced toxicity to surrounding organs. Focal treatment using LDR brachytherapy has been relatively unexplored, but it may offer advantages over other modalities that have established experiences with a focal approach. This is particularly true as prostate cancer is being detected at an earlier and more localized stage with the advent of better detection methods and newer imaging modalities. Keywords: prostate cancer, focal, low dose rate, brachytherapy

  13. Dose escalation using conformal high-dose-rate brachytherapy improves outcome in unfavorable prostate cancer

    International Nuclear Information System (INIS)

    Martinez, Alvaro A.; Gustafson, Gary; Gonzalez, Jose; Armour, Elwood; Mitchell, Chris; Edmundson, Gregory; Spencer, William; Stromberg, Jannifer; Huang, Raywin; Vicini, Frank

    2002-01-01

    Purpose: To overcome radioresistance for patients with unfavorable prostate cancer, a prospective trial of pelvic external beam irradiation (EBRT) interdigitated with dose-escalating conformal high-dose-rate (HDR) prostate brachytherapy was performed. Methods and Materials: Between November 1991 and August 2000, 207 patients were treated with 46 Gy pelvic EBRT and increasing HDR brachytherapy boost doses (5.50-11.5 Gy/fraction) during 5 weeks. The eligibility criteria were pretreatment prostate-specific antigen level ≥10.0 ng/mL, Gleason score ≥7, or clinical Stage T2b or higher. Patients were divided into 2 dose levels, low-dose biologically effective dose 93 Gy (149 patients). No patient received hormones. We used the American Society for Therapeutic Radiology and Oncology definition for biochemical failure. Results: The median age was 69 years. The mean follow-up for the group was 4.4 years, and for the low and high-dose levels, it was 7.0 and 3.4 years, respectively. The actuarial 5-year biochemical control rate was 74%, and the overall, cause-specific, and disease-free survival rate was 92%, 98%, and 68%, respectively. The 5-year biochemical control rate for the low-dose group was 52%; the rate for the high-dose group was 87% (p<0.001). Improvement occurred in the cause-specific survival in favor of the brachytherapy high-dose level (p=0.014). On multivariate analysis, a low-dose level, higher Gleason score, and higher nadir value were associated with increased biochemical failure. The Radiation Therapy Oncology Group Grade 3 gastrointestinal/genitourinary complications ranged from 0.5% to 9%. The actuarial 5-year impotency rate was 51%. Conclusion: Pelvic EBRT interdigitated with transrectal ultrasound-guided real-time conformal HDR prostate brachytherapy boost is both a precise dose delivery system and a very effective treatment for unfavorable prostate cancer. We demonstrated an incremental beneficial effect on biochemical control and cause

  14. Brachytherapy. High dose rate brachytherapy - Radiation protection: medical sheet ED 4287

    International Nuclear Information System (INIS)

    Celier, D.; Aubert, B.; Vidal, J.P.; Biau, A.; Lahaye, T.; Gauron, C.; Barret, C.; Boisserie, G.; Branchet, E.; Gambini, D.; Gondran, C.; Le Guen, B.; Guerin, C.; Nguyen, S.; Pierrat, N.; Sarrazin, T.; Donnarieix, D.

    2010-02-01

    After having indicated the required authorization to implement brachytherapy techniques, this document presents the various aspects and measures related to radiation protection when performing high-dose-rate brachytherapy treatments. It presents the concerned personnel, describes the operational process, indicates the associated hazards and the risk related to ionizing radiation, and describes how the risk is to be assessed and how exposure levels are to be determined (elements of risk assessment, delimitation of controlled and monitored areas, personnel classification, and choice of the dose monitoring method). It describes the various components of a risk management strategy (risk reduction, technical measures regarding the installation and the personnel, training and information, prevention and medical monitoring). It briefly presents how risk management is to be assessed, and mentions other related risks (biological risk, handling and posture, handling of heavy loads, mental workload, chemical risk)

  15. Brachytherapy. Pulsed dose rate brachytherapy - Radiation protection: medical sheet ED 4250

    International Nuclear Information System (INIS)

    Celier, D.; Aubert, B.; Vidal, J.P.; Biau, A.; Lahaye, T.; Gauron, C.; Barret, C.; Boisserie, G.; Branchet, E.; Gambini, D.; Gondran, C.; Le Guen, B.; Guerin, C.; Nguyen, S.; Pierrat, N.; Sarrazin, T.; Donnarieix, D.

    2009-06-01

    After having indicated the required authorization to implement brachytherapy techniques, this document presents the various aspects and measures related to radiation protection when performing pulsed-dose-rate brachytherapy treatments. It presents the concerned personnel, describes the operational process, indicates the associated hazards and the risk related to ionizing radiation, and describes how the risk is to be assessed and how exposure levels are to be determined (elements of risk assessment, delimitation of controlled and monitored areas, personnel classification, and choice of the dose monitoring method). It describes the various components of a risk management strategy (risk reduction, technical measures regarding the installation and the personnel, training and information, prevention and medical monitoring). It briefly presents how risk management is to be assessed, and mentions other related risks (biological risk, handling and posture, handling of heavy loads, mental workload, chemical risk)

  16. High dose rate versus low dose rate brachytherapy for oral cancer--a meta-analysis of clinical trials.

    Directory of Open Access Journals (Sweden)

    Zhenxing Liu

    Full Text Available To compare the efficacy and safety of high dose rate (HDR and low dose rate (LDR brachytherapy in treating early-stage oral cancer.A systematic search of MEDLINE, EMBASE and Cochrane Library databases, restricted to English language up to June 1, 2012, was performed to identify potentially relevant studies.Only randomized controlled trials (RCT and controlled trials that compared HDR to LDR brachytherapy in treatment of early-stage oral cancer (stages I, II and III were of interest.Two investigators independently extracted data from retrieved studies and controversies were solved by discussion. Meta-analysis was performed using RevMan 5.1. One RCT and five controlled trials (607 patients: 447 for LDR and 160 for HDR met the inclusion criteria. The odds ratio showed no statistically significant difference between LDR group and HDR group in terms of local recurrence (OR = 1.12, CI 95% 0.62-2.01, overall mortality (OR = 1.01, CI 95% 0.61-1.66 and Grade 3/4 complications (OR = 0.86, CI 95% 0.52-1.42.This meta-analysis indicated that HDR brachytherapy was a comparable alternative to LDR brachytherapy in treatment of oral cancer. HDR brachytherapy might become a routine choice for early-stage oral cancer in the future.

  17. Dose escalation using conformal high-dose-rate brachytherapy improves outcome in unfavorable prostate cancer.

    Science.gov (United States)

    Martinez, Alvaro A; Gustafson, Gary; Gonzalez, José; Armour, Elwood; Mitchell, Chris; Edmundson, Gregory; Spencer, William; Stromberg, Jannifer; Huang, Raywin; Vicini, Frank

    2002-06-01

    To overcome radioresistance for patients with unfavorable prostate cancer, a prospective trial of pelvic external beam irradiation (EBRT) interdigitated with dose-escalating conformal high-dose-rate (HDR) prostate brachytherapy was performed. Between November 1991 and August 2000, 207 patients were treated with 46 Gy pelvic EBRT and increasing HDR brachytherapy boost doses (5.50-11.5 Gy/fraction) during 5 weeks. The eligibility criteria were pretreatment prostate-specific antigen level >or=10.0 ng/mL, Gleason score >or=7, or clinical Stage T2b or higher. Patients were divided into 2 dose levels, low-dose biologically effective dose 93 Gy (149 patients). No patient received hormones. We used the American Society for Therapeutic Radiology and Oncology definition for biochemical failure. The median age was 69 years. The mean follow-up for the group was 4.4 years, and for the low and high-dose levels, it was 7.0 and 3.4 years, respectively. The actuarial 5-year biochemical control rate was 74%, and the overall, cause-specific, and disease-free survival rate was 92%, 98%, and 68%, respectively. The 5-year biochemical control rate for the low-dose group was 52%; the rate for the high-dose group was 87% (p failure. The Radiation Therapy Oncology Group Grade 3 gastrointestinal/genitourinary complications ranged from 0.5% to 9%. The actuarial 5-year impotency rate was 51%. Pelvic EBRT interdigitated with transrectal ultrasound-guided real-time conformal HDR prostate brachytherapy boost is both a precise dose delivery system and a very effective treatment for unfavorable prostate cancer. We demonstrated an incremental beneficial effect on biochemical control and cause-specific survival with higher doses. These results, coupled with the low risk of complications, the advantage of not being radioactive after implantation, and the real-time interactive planning, define a new standard for treatment.

  18. High dose rate brachytherapy for the palliation of malignant dysphagia

    International Nuclear Information System (INIS)

    Homs, Marjolein Y.V.; Eijkenboom, Wilhelmina M.H.; Coen, Veronique L.M.A.; Haringsma, Jelle; Blankenstein, Mark van; Kuipers, Ernst J.; Siersema, Peter D.

    2003-01-01

    Background and purpose: High dose rate (HDR) brachytherapy is a commonly used palliative treatment for esophageal carcinoma. We evaluated the outcome of HDR brachytherapy in patients with malignant dysphagia. Material and methods: A retrospective analysis over a 10-year period was performed of 149 patients treated with HDR brachytherapy, administered in one or two sessions, at a median dose of 15 Gy. Patients were evaluated for functional outcome, complications, recurrent dysphagia, and survival. Results: At 6 weeks after HDR brachytherapy, dysphagia scores had improved from a median of 3 to 2 (n=104; P<0.001), however, dysphagia had not improved in 51 (49%) patients. Procedure-related complications occurred in seven (5%) patients. Late complications, including fistula formation or bleeding, occurred in 11 (7%) patients. Twelve (8%) patients experienced minor retrosternal pain. Median survival of the patients was 160 days with a 1-year survival rate of 15%. Procedure-related mortality was 2%. At follow-up, 55 (37%) patients experienced recurrent dysphagia. In 34 (23%) patients a metal stent was placed to relieve persistent or recurrent dysphagia. Conclusion: HDR brachytherapy is a moderately effective treatment for the palliation of malignant dysphagia. The incidence of early major complications is low, however, persistent and recurrent dysphagia occur frequently, and require often additional treatment

  19. Australian high-dose-rate brachytherapy protocols for gynaecological malignancy

    International Nuclear Information System (INIS)

    MacLeod, C.; Dally, M.; Stevens, M.; Thornton, D.; Carruthers, S.; Jeal, P.

    2001-01-01

    There is no consensus over the optimal dose fractionation schedules for high-dose-rate (HDR) brachytherapy used for gynaecological malignancy. In Australian public hospital departments of radiation oncology, HDR brachytherapy for gynaecological cancer is being more commonly used. A survey of public departments that are using this technology, or that plan to introduce this technology, was performed. Their current protocols are presented. In general, protocols are similar biologically; however, the practical aspects such as the number of fractions given do vary and may reflect resource restrictions or, alternatively, differences in interpretations of the literature and of the best protocols by clinicians. Copyright (2001) Blackwell Science Pty Ltd

  20. Brachytherapy for Buccal Cancer: From Conventional Low Dose Rate (LDR) or Mold Technique to High Dose Rate Interstitial Brachytherapy (HDR-ISBT).

    Science.gov (United States)

    Kotsuma, Tadayuki; Yamazaki, Hideya; Masui, Koji; Yoshida, Ken; Shimizutani, Kimishige; Akiyama, Hironori; Murakami, Shumei; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko; Tanaka, Eiichi

    2017-12-01

    To examine the effectiveness of newly-installed high-dose-rate interstitial brachytherapy (HDR-ISBT) for buccal cancer. We retrospectively reviewed 36 patients (25 men and 11 women) with buccal cancer treated with curative brachytherapy with or without external radiotherapy with a median follow-up of 99 months. A total of 15 HDR-ISBT (median 48 Gy/ 8 fractions, range=24-60 Gy) patients were compared to conventional 15 cases LDR-ISBT (70 Gy, range=42.8-110 Gy) and 7 molds techniques (15 Gy, range=9-74 Gy). A total of 31 patients also underwent external radiotherapy (30 Gy, range=24-48 Gy). They comprised of 3T1, 23 T2, 8 T3, 3 T4 including 11 node positive cases. HDR-ISBT provided 82% of local control rate at 5 years, whereas conventional brachytherapy showed 72% [p=0.44; LDR-ISBT (65%), mold therapy (85.7%)]. Patients with early lesions (T1-2 or stage I-II) showed better local control rates than those with advanced lesions (T3-4 or stage III-IV). Severe late grade 3 complications developed in two patients treated with LDR-ISBT and EBRT. There is no significant difference in toxicity grade ≤2 between conventional brachytherapy (5/15=33%) and HDR-ISBT (7/32=32%, p=0.92). HDR-ISBT achieved good and comparable local control rates to conventional brachytherapy without elevating the toxicity. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  1. LDR brachytherapy: can low dose rate hypersensitivity from the "inverse" dose rate effect cause excessive cell killing to peripherial connective tissues and organs?

    Science.gov (United States)

    Leonard, B E; Lucas, A C

    2009-02-01

    Examined here are the possible effects of the "inverse" dose rate effect (IDRE) on low dose rate (LDR) brachytherapy. The hyper-radiosensitivity and induced radioresistance (HRS/IRR) effect benefits cell killing in radiotherapy, and IDRE and HRS/IRR seem to be generated from the same radioprotective mechanisms. We have computed the IDRE excess cell killing experienced in LDR brachytherapy using permanent seed implants. We conclude, firstly, that IDRE is a dose rate-dependent manifestation of HRS/IRR. Secondly, the presence of HRS/IRR or IDRE in a cell species or tissue must be determined by direct dose-response measurements. Thirdly, a reasonable estimate is that 50-80% of human adjoining connective and organ tissues experience IDRE from permanent implanted LDR brachytherapy. If IDRE occurs for tissues at point A for cervical cancer, the excess cell killing will be about a factor of 3.5-4.0 if the initial dose rate is 50-70 cGy h(-1). It is greater for adjacent tissues at lower dose rates and higher for lower initial dose rates at point A. Finally, higher post-treatment complications are observed in LDR brachytherapy, often for unknown reasons. Some of these are probably a result of IDRE excess cell killing. Measurements of IDRE need be performed for connective and adjacent organ tissues, i.e. bladder, rectum, urinary tract and small bowels. The measured dose rate-dependent dose responses should extended to tissues and organs remain above IDRE thresholds).

  2. Independent technique of verifying high-dose rate (HDR) brachytherapy treatment plans

    International Nuclear Information System (INIS)

    Saw, Cheng B.; Korb, Leroy J.; Darnell, Brenda; Krishna, K. V.; Ulewicz, Dennis

    1998-01-01

    Purpose: An independent technique for verifying high-dose rate (HDR) brachytherapy treatment plans has been formulated and validated clinically. Methods and Materials: In HDR brachytherapy, dwell times at respective dwell positions are computed, using an optimization algorithm in a HDR treatment-planning system to deliver a specified dose to many target points simultaneously. Because of the variability of dwell times, concerns have been expressed regarding the ability of the algorithm to compute the correct dose. To address this concern, a commercially available low-dose rate (LDR) algorithm was used to compute the doses at defined distances, based on the dwell times obtained from the HDR treatment plans. The percent deviation between doses computed using the HDR and LDR algorithms were reviewed for HDR procedures performed over the last year. Results: In this retrospective study, the difference between computed doses using the HDR and LDR algorithms was found to be within 5% for about 80% of the HDR procedures. All of the reviewed procedures have dose differences of less than 10%. Conclusion: An independent technique for verifying HDR brachytherapy treatment plans has been validated based on clinical data. Provided both systems are available, this technique is universal in its applications and not limited to either a particular implant applicator, implant site, or implant type

  3. Brachytherapy treatment with high dose rate

    International Nuclear Information System (INIS)

    Santana Rodriguez, Sergio Marcelino; Rodriguez Rodriguez, Lissi Lisbet; Ciscal Chiclana, Onelio Alberto

    2009-01-01

    Retrospectively analyze results and prognostic factors of cervical cancer patients treated with radio concomitant cisplatin-based chemotherapy, radiation therapy combined modality. Methods: From January 2003 to December 2007, 198 patients with invasive cervical cancer were treated at the Oncology Department of Hospital Robau Celestino Hernandez (brachytherapy performed at INOR). The most common age group was 31 to 40 years. The histology in squamous cell carcinoma accounted for 84.3% of cases. The treatment consisted of external pelvic irradiation and vaginal brachytherapy, high dose rate. Concomitant chemotherapy consisted of cisplatin 40 mg/m2 weekly with a maximum of 70 mg for 5 weeks. Results: 66.2% of patients completed 5 cycles of chemotherapy. The median overall survival was 39 months, overall survival, disease-free survival and survival free of locoregional recurrence at 5 years of 78%, 76% and 78.6% respectively .. We found that clinical stage, histological type (adenocarcinoma worst outcome) were statistically related to level of response. Conclusions: Treatment with external pelvic radiation, brachytherapy and concurrent weekly cisplatin in patients with stage IIIB cervical cancer is feasible in the Chilean public health system, well tolerated and results comparable to international literature. (Author)

  4. Comparison of high-dose-rate and low-dose-rate brachytherapy in the treatment of endometrial carcinoma

    International Nuclear Information System (INIS)

    Fayed, Alaa; Mutch, David G.; Rader, Janet S.; Gibb, Randall K.; Powell, Matthew A.; Wright, Jason D.; El Naqa, Issam; Zoberi, Imran; Grigsby, Perry W.

    2007-01-01

    Purpose: To compare the outcomes for endometrial carcinoma patients treated with either high-dose-rate (HDR) or low-dose-rate (LDR) brachytherapy. Methods and Materials: This study included 1,179 patients divided into LDR (1,004) and HDR groups (175). Patients with International Federation of Gynecology and Obstetrics (FIGO) surgical Stages I-III were included. All patients were treated with postoperative irradiation. In the LDR group, the postoperative dose applied to the vaginal cuff was 60-70 Gy surface doses to the vaginal mucosa. The HDR brachytherapy prescription was 6 fractions of 2 Gy each to a depth of 0.5 cm from the surface of the vaginal mucosa. Overall survival, disease-free survival, local control, and complications were endpoints. Results: For all stages combined, the overall survival, disease-free survival, and local control at 5 years in the LDR group were 70%, 69%, and 81%, respectively. For all stages combined, the overall survival, disease-free survival, and local control at 5 years in the HDR group were 68%, 62%, and 78%, respectively. There were no significant differences in early or late Grade III and IV complications in the HDR or LDR groups. Conclusion: Survival outcomes, pelvic tumor control, and Grade III and IV complications were not significantly different in the LDR brachytherapy group compared with the HDR group

  5. High-dose-rate brachytherapy in uterine cervical carcinoma

    International Nuclear Information System (INIS)

    Patel, Firuza D.; Rai, Bhavana; Mallick, Indranil; Sharma, Suresh C.

    2005-01-01

    Purpose: High-dose-rate (HDR) brachytherapy is in wide use for curative treatment of cervical cancer. The American Brachytherapy Society has recommended that the individual fraction size be <7.5 Gy and the range of fractions should be four to eight; however, many fractionation schedules, varying from institution to institution, are in use. We use 9 Gy/fraction of HDR in two to five fractions in patients with carcinoma of the uterine cervix. We found that our results and toxicity were comparable to those reported in the literature and hereby present our experience with this fractionation schedule. Methods and Materials: A total of 121 patients with Stage I-III carcinoma of the uterine cervix were treated with HDR brachytherapy between 1996 and 2000. The total number of patients analyzed was 113. The median patient age was 53 years, and the histopathologic type was squamous cell carcinoma in 93% of patients. The patients were subdivided into Groups 1 and 2. In Group 1, 18 patients with Stage Ib-IIb disease, tumor size <4 cm, and preserved cervical anatomy underwent simultaneous external beam radiotherapy to the pelvis to a dose of 40 Gy in 20 fractions within 4 weeks with central shielding and HDR brachytherapy of 9 Gy/fraction, given weekly, and interdigitated with external beam radiotherapy. The 95 patients in Group 2, who had Stage IIb-IIIb disease underwent external beam radiotherapy to the pelvis to a dose of 46 Gy in 23 fractions within 4.5 weeks followed by two sessions of HDR intracavitary brachytherapy of 9 Gy each given 1 week apart. The follow-up range was 3-7 years (median, 36.4 months). Late toxicity was graded according to the Radiation Therapy Oncology Group criteria. Results: The 5-year actuarial local control and disease-free survival rate was 74.5% and 62.0%, respectively. The actuarial local control rate at 5 years was 100% for Stage I, 80% for Stage II, and 67.2% for Stage III patients. The 5-year actuarial disease-free survival rate was 88.8% for

  6. Audits in high dose rate brachytherapy in Brazil

    International Nuclear Information System (INIS)

    Marechal, M.H.; Rosa, L.A.; Velasco, A.; Paiva, E. de; Goncalves, M.; Castelo, L.C.

    2002-01-01

    The lack of well established dosimetry protocols for HDR sources is a point of great concern regarding the uniformity of procedures within a particular country. The main objective of this paper is to report the results of an implementation of the audit program in dosimetry of high dose rate brachytherapy sources used by the radiation therapy centers in Brazil. In Brazil, among 169 radiotherapy centers, 35 have HDR brachytherapy systems. This program started in August 2001 and until now eight radiotherapy services were audited. The audit program consists of the visit in loco to each center and the evaluation of the intensity of the source with a well type chamber specially design for HDR 192 Ir sources. The measurements was carried out with a HDR1000PLUS Brachytherapy Well Type Chamber and a MAX 4000 Electrometer, both manufactured by Standard Imaging Inc. The chamber was calibrated in air kerma strength by the Accredited Dosimetry Calibration Laboratory, Department of Medical Physics, University of Wisconsin in the USA. The same chamber was calibrated in Brazil using a 192 lr high dose rate source whose intensity was determined by 60 Co gamma rays and 250 kV x rays interpolation methodology. The Nk of 60 Co and 250 kV x rays were provided by the Brazilian National Standard Laboratory for Ionizing Radiation (LMNRI)

  7. Impact of catheter reconstruction error on dose distribution in high dose rate intracavitary brachytherapy and evaluation of OAR doses

    International Nuclear Information System (INIS)

    Thaper, Deepak; Shukla, Arvind; Rathore, Narendra; Oinam, Arun S.

    2016-01-01

    In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this study is to evaluate the impact of catheter reconstruction error on dose distribution in CT based intracavitary brachytherapy planning and evaluation of its effect on organ at risk (OAR) like bladder, rectum and sigmoid and target volume High risk clinical target volume (HR-CTV)

  8. Dosimetry Modeling for Focal Low-Dose-Rate Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Al-Qaisieh, Bashar [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Mason, Josh, E-mail: joshua.mason@nhs.net [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Bownes, Peter; Henry, Ann [Leeds Cancer Centre, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Dickinson, Louise [Division of Surgery and Interventional Science, University College London, London (United Kingdom); Department of Radiology, Northwick Park Hospital, London North West NHS Trust, London (United Kingdom); Ahmed, Hashim U. [Division of Surgery and Interventional Science, University College London, London (United Kingdom); University College London Hospital, London (United Kingdom); Emberton, Mark [University College London Hospital, London (United Kingdom); Langley, Stephen [St Luke' s Cancer Centre, Guildford (United Kingdom)

    2015-07-15

    Purpose: Focal brachytherapy targeted to an individual lesion(s) within the prostate may reduce side effects experienced with whole-gland brachytherapy. The outcomes of a consensus meeting on focal prostate brachytherapy were used to investigate optimal dosimetry of focal low-dose-rate (LDR) prostate brachytherapy targeted using multiparametric magnetic resonance imaging (mp-MRI) and transperineal template prostate mapping (TPM) biopsy, including the effects of random and systematic seed displacements and interseed attenuation (ISA). Methods and Materials: Nine patients were selected according to clinical characteristics and concordance of TPM and mp-MRI. Retrospectively, 3 treatment plans were analyzed for each case: whole-gland (WG), hemi-gland (hemi), and ultra-focal (UF) plans, with 145-Gy prescription dose and identical dose constraints for each plan. Plan robustness to seed displacement and ISA were assessed using Monte Carlo simulations. Results: WG plans used a mean 28 needles and 81 seeds, hemi plans used 17 needles and 56 seeds, and UF plans used 12 needles and 25 seeds. Mean D90 (minimum dose received by 90% of the target) and V100 (percentage of the target that receives 100% dose) values were 181.3 Gy and 99.8% for the prostate in WG plans, 195.7 Gy and 97.8% for the hemi-prostate in hemi plans, and 218.3 Gy and 99.8% for the focal target in UF plans. Mean urethra D10 was 205.9 Gy, 191.4 Gy, and 92.4 Gy in WG, hemi, and UF plans, respectively. Mean rectum D2 cm{sup 3} was 107.5 Gy, 77.0 Gy, and 42.7 Gy in WG, hemi, and UF plans, respectively. Focal plans were more sensitive to seed displacement errors: random shifts with a standard deviation of 4 mm reduced mean target D90 by 14.0%, 20.5%, and 32.0% for WG, hemi, and UF plans, respectively. ISA has a similar impact on dose-volume histogram parameters for all plan types. Conclusions: Treatment planning for focal LDR brachytherapy is feasible. Dose constraints are easily met with a notable

  9. Fractionation in medium dose rate brachytherapy of cancer of the cervix

    International Nuclear Information System (INIS)

    Leborgne, Felix; Fowler, Jack F.; Leborgne, Jose H.; Zubizarreta, Eduardo; Chappell, Rick

    1996-01-01

    Purpose: To establish an optimum fractionation for medium dose rate (MDR) brachytherapy from retrospective data of patients treated with different MDR schedules in comparison with a low dose rate (LDR) schedule. Methods and Materials: The study population consists of consecutive Stage IB-IIA-IIB patients who received radiotherapy alone with full dose brachytherapy plus external beam pelvic and parametrial irradiation from 1986-1993. Patients also receiving surgery or chemotherapy were excluded. The LDR group (n = 102, median follow-up: 80 months) received a median dose to Point A of two 32.5 Gy fractions at 0.44 Gy/h plus 18 Gy of external whole pelvic irradiation. The MDR1 group (n = 30, median follow-up: 45 months) received a mean dose of two 32 Gy fractions at 1.68 Gy/h. An individual dose reduction of 12.5% was planned for this group according to the Manchester experience, but only a 4.8% dose reduction was achieved. The MDR2 group (n = 10, median follow-up: 36 months) received a dose of two 24 Gy fractions at 1.65 Gy/h. The MDR3 group (n = 10, median follow-up 33 months) received a mean dose of three 15.3 Gy fractions at 1.64 Gy/h. And finally, the MDR4 group (n = 38, median follow-up: 24 months) received six 7.7 Gy fractions from two pulses 6 h apart in each of three insertions at 1.61 Gy/h. The median external pelvic dose to MDR schedules was between 12 and 20 Gy. The linear quadratic (LQ) formula was used to calculate the biologically effective dose (BED) to tumor (Gy 10 ) and rectum (Gy 3 ), assuming T(1(2)) for repair = 1.5 h. Results: The crude central recurrence rate was 6% for LDR (mean BED = 95.4 Gy 10 ) and 10% for MDR4 (mean BED = 77.0 Gy 10 ) (p = NS). The remaining MDR groups had no recurrences. Grade 2 and 3 rectal or bladder complications were 0% for LDR (rectal BED = 109 Gy 3 ), 83% for MDR1 (BED = 206 Gy 3 ), and 30% for MDR3 (BED = 127 Gy 3 ). The MDR2 and MDR4 groups presented no complications (BED, 123 Gy 3 , and 105 Gy 3 , respectively

  10. Salvage high-dose-rate brachytherapy for local prostate cancer recurrence after radical radiotherapy

    Directory of Open Access Journals (Sweden)

    V. A. Solodkiy

    2016-01-01

    Full Text Available Studies salvage interstitial radiation therapy for recurrent prostate cancer, launched at the end of the XX century. In recent years, more and more attention is paid to high-dose-rate brachytherapy (HDR-BT as a method of treating local recurrence.The purpose of research – preliminary clinical results of salvage high-dose-rate brachytherapy applied in cases of suspected local recurrence or of residual tumour after radiotherapy.Preliminary findings indicate the possibility of using HDR-BT, achieving local tumor control with low genitourinary toxicity.

  11. Radiation safety program in high dose rate brachytherapy facility at INHS Asvini

    Directory of Open Access Journals (Sweden)

    Kirti Tyagi

    2014-01-01

    Full Text Available Brachytherapy concerns primarily the use of radioactive sealed sources which are inserted into catheters or applicators and placed directly into tissue either inside or very close to the target volume. The use of radiation in treatment of patients involves both benefits and risks. It has been reported that early radiation workers had developed radiation induced cancers. These incidents lead to continuous work for the improvement of radiation safety of patients and personnel The use of remote afterloading equipment has been developed to improve radiation safety in the delivery of treatment in brachytherapy. The widespread adoption of high dose rate brachytherapy needs appropriate quality assurance measures to minimize the risks to both patients and medical staff. The radiation safety program covers five major aspects: quality control, quality assurance, radiation monitoring, preventive maintenance, administrative measures and quality audit. This paper will discuss the radiation safety program developedfor a high dose rate brachytherapy facility at our centre which may serve as a guideline for other centres intending to install a similar facility.

  12. Treatment of the prostate cancer with high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Martinez, Alvaro; Torres Silva, Felipe

    2002-01-01

    The prostate cancer treatment in early stages is controversial. The high dose rate brachytherapy has been used like monotherapy or boost with external beam radiotherapy in advanced disease. This paper describes the technique and the advantages over other modalities

  13. Combination of high-dose rate brachytherapy and external beam radiotherapy for the treatment of advanced scalp angiosarcoma - case report

    International Nuclear Information System (INIS)

    Gentil, Andre Cavalcanti; Lima Junior, Carlos Genesio Bezerra; Soboll, Danyel Scheidegger; Novaes, Paulo Eduardo R.S.; Pereira, Adelino Jose; Pellizon, Antonio Carlos Assis

    2001-01-01

    The authors report a case of a patient with an extensive angiosarcoma of the scalp that was submitted only to radiotherapy with a combination of orthovoltage roentgentherapy and high-dose rate brachytherapy, using a mould. The clinical and technical features as well as the therapeutic outcome are presented, and the usefulness and peculiarities of high-dose rate brachytherapy for this particular indication is discussed. A comparative analysis of the difficulties and limitations of employing low-dose rate brachytherapy is also presented. The authors concluded that high-dose rate brachytherapy might be an useful, practical and safe option to treat neoplastic lesions of the scalp, and an alternative treatment to electrontherapy. (author)

  14. Dosimetry in high dose rate endoluminal brachytherapy

    International Nuclear Information System (INIS)

    Uno, Takashi; Kotaka, Kikuo; Itami, Jun

    1994-01-01

    In endoluminal brachytherapy for the tracheobronchial tree, esophagus, and bile duct, a reference point for dose calculation has been often settled at 1 cm outside from the middle of source travel path. In the current study, a change in the ratio of the reference point dose on the convex to concave side (Dq/Dp) was calculated, provided the source travel path bends as is the case in most endoluminal brachytherapies. Point source was presumed to move stepwise at 1 cm interval from 4 to 13 locations. Retention time at each location was calculated by personal computer so as to deliver equal dose at 1 cm from the linear travel path. With the retention time remaining constant, the change of Dq/Dp was assessed by bending the source travel path. Results indicated that the length of the source travel path and radius of its curve influenced the pattern of change in Dq/Dp. Therefore, it was concluded that the difference in reference dose on the convex and concave side of the curved path is not negligible under certain conditions in endoluminal brachytherapy. In order to maintain the ratio more than 0.9, relatively greater radius was required when the source travel path was decreased. (author)

  15. High versus low-dose rate brachytherapy for cervical cancer.

    Science.gov (United States)

    Patankar, Sonali S; Tergas, Ana I; Deutsch, Israel; Burke, William M; Hou, June Y; Ananth, Cande V; Huang, Yongmei; Neugut, Alfred I; Hershman, Dawn L; Wright, Jason D

    2015-03-01

    Brachytherapy plays an important role in the treatment of cervical cancer. While small trials have shown comparable survival outcomes between high (HDR) and low-dose rate (LDR) brachytherapy, little data is available in the US. We examined the utilization of HDR brachytherapy and analyzed the impact of type of brachytherapy on survival for cervical cancer. Women with stages IB2-IVA cervical cancer treated with primary (external beam and brachytherapy) radiotherapy between 2003-2011 and recorded in the National Cancer Database (NCDB) were analyzed. Generalized linear mixed models and Cox proportional hazards regression were used to examine predictors of HDR brachytherapy use and the association between HDR use and survival. A total of 10,564 women including 2681 (25.4%) who received LDR and 7883 (74.6%) that received HDR were identified. Use of HDR increased from 50.2% in 2003 to 83.9% in 2011 (Puse of HDR. While patients in the Northeast were more likely to receive HDR therapy, there were no other clinical or socioeconomic characteristics associated with receipt of HDR. In a multivariable Cox model, survival was similar between the HDR and LDR groups (HR=0.93; 95% CI 0.83-1.03). Similar findings were noted in analyses stratified by stage and histology. Kaplan-Meier analyses demonstrated no difference in survival based on type of brachytherapy for stage IIB (P=0.68), IIIB (P=0.17), or IVA (P=0.16) tumors. The use of HDR therapy has increased rapidly. Overall survival is similar for LDR and HDR brachytherapy. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Monte Carlo dosimetry of the IRAsource high dose rate 192Ir brachytherapy source

    International Nuclear Information System (INIS)

    Sarabiasl, Akbar; Ayoobian, Navid; Jabbari, Iraj; Poorbaygi, Hossein; Javanshir, Mohammad Reza

    2016-01-01

    High-dose-rate (HDR) brachytherapy is a common method for cancer treatment in clinical brachytherapy. Because of the different source designs, there is a need for specific dosimetry data set for each HDR model. The purpose of this study is to obtain detailed dose rate distributions in water phantom for a first prototype HDR 192 Ir brachytherapy source model, IRAsource, and compare with the other published works. In this study, Monte Carlo N-particle (MCNP version 4C) code was used to simulate the dose rate distributions around the HDR source. A full set of dosimetry parameters reported by the American Association of Physicists in Medicine Task Group No. 43U1 was evaluated. Also, the absorbed dose rate distributions in water, were obtained in an along-away look-up table. The dose rate constant, Λ, of the IRAsource was evaluated to be equal to 1.112 ± 0.005 cGy h −1 U −1 . The results of dosimetry parameters are presented in tabulated and graphical formats and compared with those reported from other commercially available HDR 192 Ir sources, which are in good agreement. This justifies the use of specific data sets for this new source. The results obtained in this study can be used as input data in the conventional treatment planning systems.

  17. Treatment Outcome of Medium-Dose-Rate Intracavitary Brachytherapy for Carcinoma of the Uterine Cervix: Comparison With Low-Dose-Rate Intracavitary Brachytherapy

    International Nuclear Information System (INIS)

    Kaneyasu, Yuko; Kita, Midori; Okawa, Tomohiko; Maebayashi, Katsuya; Kohno, Mari; Sonoda, Tatsuo; Hirabayashi, Hisae; Nagata, Yasushi; Mitsuhashi, Norio

    2012-01-01

    Purpose: To evaluate and compare the efficacy of medium-dose-rate (MDR) and low-dose-rate (LDR) intracavitary brachytherapy (ICBT) for uterine cervical cancer. Methods and Materials: We evaluated 419 patients with squamous cell carcinoma of the cervix who were treated by radical radiotherapy with curative intent at Tokyo Women’s Medical University from 1969 to 1999. LDR was used from 1969 to 1986, and MDR has been used since July 1987. When compared with LDR, fraction dose was decreased and fraction size was increased (1 or 2 fractions) for MDR to make the total dose of MDR equal to that of LDR. In general, the patients received a total dose of 60 to 70 Gy at Point A with external beam radiotherapy combined with brachytherapy according to the International Federation of Gynecology and Obstetrics stage. In the LDR group, 32 patients had Stage I disease, 81 had Stage II, 182 had Stage III, and 29 had Stage IVA; in the MDR group, 9 patients had Stage I disease, 19 had Stage II, 55 had Stage III, and 12 had Stage IVA. Results: The 5-year overall survival rates for Stages I, II, III, and IVA in the LDR group were 78%, 72%, 55%, and 34%, respectively. In the MDR group, the 5-year overall survival rates were 100%, 68%, 52%, and 42%, respectively. No significant statistical differences were seen between the two groups. The actuarial rates of late complications Grade 2 or greater at 5 years for the rectum, bladder, and small intestine in the LDR group were 11.1%, 5.8%, and 2.0%, respectively. The rates for the MDR group were 11.7%, 4.2%, and 2.6%, respectively, all of which were without statistical differences. Conclusion: These data suggest that MDR ICBT is effective, useful, and equally as good as LDR ICBT in daytime (about 5 hours) treatments of patients with cervical cancer.

  18. Treatment Outcome of Medium-Dose-Rate Intracavitary Brachytherapy for Carcinoma of the Uterine Cervix: Comparison With Low-Dose-Rate Intracavitary Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kaneyasu, Yuko, E-mail: kaneyasu@hiroshima-u.ac.jp [Department of Radiation Oncology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima (Japan); Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan); Kita, Midori [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan); Department of Clinical Radiology, Tokyo Metropolitan Tama Medical Center, Tokyo (Japan); Okawa, Tomohiko [Evaluation and Promotion Center, Utsunomiya Memorial Hospital, Tochigi (Japan); Maebayashi, Katsuya [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan); Kohno, Mari [Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women' s Medical University Hospital, Tokyo (Japan); Sonoda, Tatsuo; Hirabayashi, Hisae [Department of Radiology, Tokyo Women' s Medical University Hospital, Tokyo (Japan); Nagata, Yasushi [Department of Radiation Oncology, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima (Japan); Mitsuhashi, Norio [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan)

    2012-09-01

    Purpose: To evaluate and compare the efficacy of medium-dose-rate (MDR) and low-dose-rate (LDR) intracavitary brachytherapy (ICBT) for uterine cervical cancer. Methods and Materials: We evaluated 419 patients with squamous cell carcinoma of the cervix who were treated by radical radiotherapy with curative intent at Tokyo Women's Medical University from 1969 to 1999. LDR was used from 1969 to 1986, and MDR has been used since July 1987. When compared with LDR, fraction dose was decreased and fraction size was increased (1 or 2 fractions) for MDR to make the total dose of MDR equal to that of LDR. In general, the patients received a total dose of 60 to 70 Gy at Point A with external beam radiotherapy combined with brachytherapy according to the International Federation of Gynecology and Obstetrics stage. In the LDR group, 32 patients had Stage I disease, 81 had Stage II, 182 had Stage III, and 29 had Stage IVA; in the MDR group, 9 patients had Stage I disease, 19 had Stage II, 55 had Stage III, and 12 had Stage IVA. Results: The 5-year overall survival rates for Stages I, II, III, and IVA in the LDR group were 78%, 72%, 55%, and 34%, respectively. In the MDR group, the 5-year overall survival rates were 100%, 68%, 52%, and 42%, respectively. No significant statistical differences were seen between the two groups. The actuarial rates of late complications Grade 2 or greater at 5 years for the rectum, bladder, and small intestine in the LDR group were 11.1%, 5.8%, and 2.0%, respectively. The rates for the MDR group were 11.7%, 4.2%, and 2.6%, respectively, all of which were without statistical differences. Conclusion: These data suggest that MDR ICBT is effective, useful, and equally as good as LDR ICBT in daytime (about 5 hours) treatments of patients with cervical cancer.

  19. The brachytherapy with low dose-rate iridium for prostate cancer

    International Nuclear Information System (INIS)

    Momma, Tetsuo; Saito, Shiro; Ohki, Takahiro; Satoh, Hiroyuki; Toya, Kazuhito; Dokiya, Takushi; Murai, Masaru

    2000-01-01

    Brachytherapy as an option for the treatment of prostate cancer has been commonly performed in USA. As the permanent seeding of the radioactive materials is strictly restricted by the law in Japan, brachytherapy must be performed by the temporary implant. This treatment has been performed at a few facilities in Japan mostly using high dose-rate iridium. Only our facility has been using low dose-rate iridium (LDR-Ir) for prostate cancer. This study evaluates the clinical results of the treatment. Since December 1997 to December 1999, 26 patients with histologically diagnosed as prostate cancer (Stage B, 92%; Stage C, 8%) underwent brachytherapy. Twenty-two patients received brachytherapy alone, three were treated with a combination of brachytherapy and external beam radiotherapy (ERT) and one was treated with a combination of brachytherapy and neoadjuvant endocrine therapy. Patients ranged in age from 61 to 84 (median 76) years old. Treatment was initiated with perineal needle placement. From 10 to 14 needles were placed through the holes on the template which was fixed to the stabilizer of the transrectal ultrasound probe. After the needle placement, CT scan was performed to draw distribution curves for the treatment planning. LDR-Ir wires were introduced to the sheath and indwelled during the time calculated from dosimetry. Peripheral dose was 70 Gy for the monotherapy of brachytherapy. For the combination therapy, 40 Gy was given by brachytherapy and 36 Gy with ERT afterwards. LDR-Ir wires were removed after completion of the radiation and patients were followed with serum PSA level and annual biopsy. During 2 to 26 (median 12) months follow-up, 8 out of 9 patients with initial PSA level above 20 ng/ml showed PSA failure. All 13 patients with initial PSA level lower than 20 ng/ml were free from PSA failure. Eight out of 11 patients with Gleason's score 7 or higher showed PSA failure, and all 14 patients (including three patients with combined therapy) with

  20. Calculations radiobiological using the quadratic lineal model in the use of the medium dose rate absorbed in brachytherapy. Pt. 3

    International Nuclear Information System (INIS)

    2002-01-01

    Calculations with the quadratic lineal model for medium rate using the equation dose-effect. Several calculations for system of low dose rate brachytherapy plus teletherapy, calculations for brachytherapy with medium dose rate together with teletherapy, dose for fraction and the one numbers of fractions in medium rate

  1. Radiation safety program in a high dose rate brachytherapy facility

    International Nuclear Information System (INIS)

    Rodriguez, L.V.; Hermoso, T.M.; Solis, R.C.

    2001-01-01

    The use of remote afterloading equipment has been developed to improve radiation safety in the delivery of treatment in brachytherapy. Several accidents, however, have been reported involving high dose-rate brachytherapy system. These events, together with the desire to address the concerns of radiation workers, and the anticipated adoption of the International Basic Safety Standards for Protection Against Ionizing Radiation (IAEA, 1996), led to the development of the radiation safety program at the Department of Radiotherapy, Jose R. Reyes Memorial Medical Center and at the Division of Radiation Oncology, St. Luke's Medical Center. The radiation safety program covers five major aspects: quality control/quality assurance, radiation monitoring, preventive maintenance, administrative measures and quality audit. Measures for evaluation of effectiveness of the program include decreased unnecessary exposures of patients and staff, improved accuracy in treatment delivery and increased department efficiency due to the development of staff vigilance and decreased anxiety. The success in the implementation required the participation and cooperation of all the personnel involved in the procedures and strong management support. This paper will discuss the radiation safety program for a high dose rate brachytherapy facility developed at these two institutes which may serve as a guideline for other hospitals intending to install a similar facility. (author)

  2. Routine quality control of high dose rate brachytherapy equipment

    International Nuclear Information System (INIS)

    Guzman Calcina, Carmen S.; Almeida, Adelaide de; Rocha, Jose R. Oliveira

    2001-01-01

    A Quality Assurance program should be installed also for High Dose Rate brachytherapy, in the order to achieve a correct dose administration to the patient and for the safety to those involved directly with the treatment. The work presented here has the following purposes: Analyze the types of equipment tests presented by the official protocols (TG40, TG56 e ARCAL XXX), evaluate the brachytherapy routine tests of protocols from various national and international radiotherapy services and compare the latter with those presented in the official protocols. As a result, we conclude the following: TG56 presents a higher number of tests when compared to the other official protocols and most of the tests presented by the analyzed services are present in TG56. A suggestion for a basic protocol is presented, emphasizing the periodicity and tolerance level of each of the tests. (author)

  3. High dose rate endobronchial brachytherapy - treatment technique

    International Nuclear Information System (INIS)

    Carvalho, Heloisa de Andrade; Aisen, Salim; Haddad, Cecilia Maria Kalil; Nadalin, Wladimir; Pedreira Junior, Wilson Leite; Chavantes, Maria Cristina

    1998-01-01

    High dose rate endobronchial brachytherapy is efficient in symptom relief due to obstructive endobronchial malignancies. However, it's role in survival improvement for patients with lung cancer is not yet established. The use of this treatment in increasing, specially in the developing countries. The purpose of this paper is to present the treatment technique used in the Radiotherapy Department of the Hospital da Clinicas, University of Sao Paulo, based on an experience of 60 cases treated with 180 procedures. Some practical suggestions and rules adopted in the Department are described. The severe complications rate is 6.7%, demonstrating an adequate patient selection associated with the technique utilized. (author)

  4. Verification of the calculation program for brachytherapy planning system of high dose rate (PLATO)

    International Nuclear Information System (INIS)

    Almansa, J.; Alaman, C.; Perez-Alija, J.; Herrero, C.; Real, R. del; Ososrio, J. L.

    2011-01-01

    In our treatments are performed brachytherapy high dose rate since 2007. The procedures performed include gynecological intracavitary treatment and interstitial. The treatments are performed with a source of Ir-192 activity between 5 and 10 Ci such that small variations in treatment times can cause damage to the patient. In addition the Royal Decree 1566/1998 on Quality Criteria in radiotherapy establishes the need to verify the monitor units or treatment time in radiotherapy and brachytherapy. All this justifies the existence of a redundant system for brachytherapy dose calculation that can reveal any abnormality is present.

  5. Novel Use of the Contura for High Dose Rate Cranial Brachytherapy

    International Nuclear Information System (INIS)

    Scanderbeg, Daniel J.; Alksne, John F.; Lawson, Joshua D.; Murphy, Kevin T.

    2011-01-01

    A popular choice for treatment of recurrent gliomas was cranial brachytherapy using the GliaSite Radiation Therapy System. However, this device was taken off the market in late 2008, thus leaving a treatment void. This case study presents our experience treating a cranial lesion for the first time using a Contura multilumen, high-dose-rate (HDR) brachytherapy balloon applicator. The patient was a 47-year-old male who was diagnosed with a recurrent right frontal anaplastic oligodendroglioma. Previous radiosurgery made him a good candidate for brachytherapy. An intracavitary HDR balloon brachytherapy device (Contura) was placed in the resection cavity and treated with a single fraction of 20 Gy. The implant, treatment, and removal of the device were all completed without incident. Dosimetry of the device was excellent because the dose conformed very well to the target. V90, V100, V150, and V200 were 98.9%, 95.7%, 27.2, and 8.8 cc, respectively. This patient was treated successfully using the Contura multilumen balloon. Contura was originally designed for deployment in a postlumpectomy breast for treatment by accelerated partial breast irradiation. Being an intracavitary balloon device, its similarity to the GliaSite system makes it a viable replacement candidate. Multiple lumens in the device also make it possible to shape the dose delivered to the target, something not possible before with the GliaSite applicator.

  6. Novel high dose rate lip brachytherapy technique to improve dose homogeneity and reduce toxicity by customized mold

    International Nuclear Information System (INIS)

    Feldman, Jon; Appelbaum, Limor; Sela, Mordechay; Voskoboinik, Ninel; Kadouri, Sarit; Weinberger, Jeffrey; Orion, Itzhak; Meirovitz, Amichay

    2014-01-01

    The purpose of this study is to describe a novel brachytherapy technique for lip Squamous Cell Carcinoma, utilizing a customized mold with embedded brachytherapy sleeves, which separates the lip from the mandible, and improves dose homogeneity. Seven patients with T2 lip cancer treated with a “sandwich” technique of High Dose Rate (HDR) brachytherapy to the lip, consisting of interstitial catheters and a customized mold with embedded catheters, were reviewed for dosimetry and outcome using 3D planning. Dosimetric comparison was made between the “sandwich” technique to “classic” – interstitial catheters only plan. We compared dose volume histograms for Clinical Tumor Volume (CTV), normal tissue “hot spots” and mandible dose. We are reporting according to the ICRU 58 and calculated the Conformal Index (COIN) to show the advantage of our technique. The seven patients (ages 36–81 years, male) had median follow-up of 47 months. Four patients received Brachytherapy and External Beam Radiation Therapy, 3 patients received brachytherapy alone. All achieved local control, with excellent esthetic and functional results. All patients are disease free. The Customized Mold Sandwich technique (CMS) reduced the high dose region receiving 150% (V150) by an average of 20% (range 1–47%), The low dose region (les then 90% of the prescribed dose) improved by 73% in average by using the CMS technique. The COIN value for the CMS was in average 0.92 as opposed to 0.88 for the interstitial catheter only. All differences (excluding the low dose region) were statistically significant. The CMS technique significantly reduces the high dose volume and increases treatment homogeneity. This may reduce the potential toxicity to the lip and adjacent mandible, and results in excellent tumor control, cosmetic and functionality

  7. Current situation of high-dose-rate brachytherapy for cervical cancer in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Rogerio Matias Vidal da; Souza, Divanizia do Nascimento, E-mail: rmv.fisica@gmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil); Pinezi, Juliana Castro Dourado [Pontificia Universidade Catolica de Goias (PUC-Goias), Goiania, GO (Brazil); Macedo, Luiz Eduardo Andrade [Hospital Chama, Arapiraca, AL (Brazil)

    2014-05-15

    To assess the current situation of high-dose-rate (HDR) brachytherapy for cancer of the cervix in Brazil, regarding apparatuses, planning methods, prescription, fractionation schedule and evaluation of dose in organs at risk. Materials and methods: in the period between March/2012 and May/2013, a multiple choice questionnaire was developed and sent to 89 Brazilian hospitals which perform HDR brachytherapy. Results: sixty-one services answered the questionnaire. All regions of the country experienced a sharp increase in the number of HDR brachytherapy services in the period from 2001 to 2013. As regards planning, although a three-dimensional planning software was available in 91% of the centers, conventional radiography was mentioned by 92% of the respondents as their routine imaging method for such a purpose. Approximately 35% of respondents said that brachytherapy sessions are performed after teletherapy. The scheme of four 7 Gy intracavitary insertions was mentioned as the most frequently practiced. Conclusion: the authors observed that professionals have difficulty accessing adjuvant three-dimensional planning tools such as computed tomography and magnetic resonance imaging. (author)

  8. In vivo dosimetry with semiconductors in medium dose rate (MDR) brachytherapy for cervical cancer.

    Science.gov (United States)

    Allahverdi, Mahmoud; Jaberi, Ramin; Aghili, Mehdi; Ghahremani, Fatemeh; Geraily, Ghazale

    2013-03-01

    This study was performed to evaluate the role of in vivo dosimetry with semiconductor detectors in gynaecological medium dose rate brachytherapy, and to compare the actual doses delivered to organs at risk (as measured using in vivo dosimetry) with those calculated during treatment planning. Doses to the rectum and bladder were measured in a group of patients with cervical carcinoma using semiconductor detectors and compared to the doses calculated using a treatment planning system. 36 applications of brachytherapy at dose rates of 1.8-2.3 Gy/h were performed in the patients. The mean differences between the measured and calculated doses were 3 % for the rectum and 11 % for the bladder. The main reason for the differences between the measured and calculated doses was patient movement. To reduce the risk of large errors in the dose delivered, in vivo dosimetry should be performed in addition to treatment planning system computations.

  9. High dose-rate brachytherapy source position quality assurance using radiochromic film

    International Nuclear Information System (INIS)

    Evans, M.D.C.; Devic, S.; Podgorsak, E.B.

    2007-01-01

    Traditionally, radiographic film has been used to verify high-dose-rate brachytherapy source position accuracy by co-registering autoradiographic and diagnostic images of the associated applicator. Filmless PACS-based clinics that do not have access to radiographic film and wet developers may have trouble performing this quality assurance test in a simple and practical manner. We describe an alternative method for quality assurance using radiochromic-type film. In addition to being easy and practical to use, radiochromic film has some advantages in comparison with traditional radiographic film when used for HDR brachytherapy quality assurance

  10. Pulsed dose rate brachytherapy (PDR): an analysis of the technique at 2 years

    Energy Technology Data Exchange (ETDEWEB)

    Thienpont, M [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; Van Eijkeren, M; Van Hecke, H; Boterberg, T; De Neve, W

    1995-12-01

    A total of 154 applications was analysed using a pulsed dose brachytherapy technique for 138 patients over a 2 year period with emphasis on technical aspects influencing the overall treatment time. Vaginal ovoids were used in 59 cases, plastic tubes in 52, a Fletcher-type in 18, vaginal cylinders in 14 and a perineal template in 11 cases. Pulses were given at hourly intervals with a median dose rate of 0.6 Gy per pulse (range 0.4 to 3 Gy). The number of pulses per application varied from 3 to 134 (median 32). The number of dwell positions varied from 1 to 542 over 1 to 18 catheters. Patient related problems were few. The room was entered almost every 77 minutes. We noted 561 status codes in 147 applications. Of the 25 different codes, the most frequent one was due to the door left open when a pulse had to be given (35%) or due to constriction of the plastic catheters at the transfer tube junction (26%). However, the median total treatment time was increased by only 5 minutes. With pulsed dose rate brachytherapy at hourly pulses we can treat our patients within the planned time despite frequent room entrance and occurrence of an appreciable number of status codes. This technique seems to fulfill its promise to replace low dose rate brachytherapy.

  11. Novel use of the Contura for high dose rate cranial brachytherapy.

    Science.gov (United States)

    Scanderbeg, Daniel J; Alksne, John F; Lawson, Joshua D; Murphy, Kevin T

    2011-01-01

    A popular choice for treatment of recurrent gliomas was cranial brachytherapy using the GliaSite Radiation Therapy System. However, this device was taken off the market in late 2008, thus leaving a treatment void. This case study presents our experience treating a cranial lesion for the first time using a Contura multilumen, high-dose-rate (HDR) brachytherapy balloon applicator. The patient was a 47-year-old male who was diagnosed with a recurrent right frontal anaplastic oligodendroglioma. Previous radiosurgery made him a good candidate for brachytherapy. An intracavitary HDR balloon brachytherapy device (Contura) was placed in the resection cavity and treated with a single fraction of 20 Gy. The implant, treatment, and removal of the device were all completed without incident. Dosimetry of the device was excellent because the dose conformed very well to the target. V90, V100, V150, and V200 were 98.9%, 95.7%, 27.2, and 8.8 cc, respectively. This patient was treated successfully using the Contura multilumen balloon. Contura was originally designed for deployment in a postlumpectomy breast for treatment by accelerated partial breast irradiation. Being an intracavitary balloon device, its similarity to the GliaSite system makes it a viable replacement candidate. Multiple lumens in the device also make it possible to shape the dose delivered to the target, something not possible before with the GliaSite applicator. Copyright © 2011 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

  12. Interstitial high-dose-rate brachytherapy in the treatment of base of tongue carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Takacsi-Nagy, Z.; Polgar, C.; Somogyi, A.; Major, T.; Fodor, J.; Nemeth, G. [Dept. of Radiotherapy, National Inst. of Oncology, Budapest (Hungary); Oberna, F. [Dept. of Maxillofacial Surgery, St. Rokus Hospital, Budapest (Hungary); Remenar, E.; Kasler, M. [Dept. of Head and Neck, Maxillofacial and Reconstructive Plastic Surgery, National Inst. of Oncology, Budapest (Hungary)

    2004-12-01

    Background and purpose: to date none of the studies examined the feasibility and efficacy of interstitial high-dose-rate (HDR) brachytherapy in the treatment of carcinoma of the tongue base. Therefore the aim of this study was to contribute to this issue. Patients and methods: between 1992 and 2000 37 patients (mean age 55 years) with T1-4 and NO-3 carcinoma of the base of tongue were presented. Neck dissection was carried out in twelve cases (32%). 30 patients with advanced stage received brachytherapy boost after 50-66.5 Gy (mean, 60 Gy) locoregional external beam irradiation (EBI) and 7 patients with early stage (T1-2, NO) were managed locally with wide tumor excision and sole brachytherapy. 4 of them underwent neck dissection and the others were subjected to 50 Gy regional EBI. The mean dose of boost and sole brachytherapy was 18 Gy and 28 Gy, respectively. Results: the median follow-up time for surviving patients was 51 months. The 7 sole brachytherapy patients are living with no evidence of disease. For patients treated with EBI and brachytherapy boost, the 5-year actuarial rate of local, locoregional recurrence-free and overall survival was 60%, 52% and 46%, respectively. For all patients in univariate analysis larger tumor size (T4 vs. T1-3) was significant negative predictor of local (RR: 7.23) and locoregional control (RR: 3.87), but nodal involvement was not. Delayed soft tissue ulceration and osteoradionecrosis occurred in 4 (13%) EBI and brachytherapy treated patients. None of the sole brachytherapy patients experienced severe late radiation toxicity. Conclusion: EBI combined with interstitial HDR brachytherapy boost result in acceptable local tumor control with low incidence of late side effects in patients with advanced disease. Fractionated sole HDR brachytherapy following tumor excision is a feasible treatment option for patients with early stage cancer and gives excellent local results. (orig.)

  13. Salvage high-dose-rate interstitial brachytherapy for locally recurrent rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pellizzon, Antonio Cassio Assis, E-mail: acapellizzon@hcancer.org.br [A.C. Camargo Cancer Center, Sao Paulo, SP (Brazil). Departamento de Radioterapia

    2016-05-15

    For tumors of the lower third of the rectum, the only safe surgical procedure is abdominal-perineal resection. High-dose-rate interstitial brachytherapy is a promising treatment for local recurrence of previously irradiated lower rectal cancer, due to the extremely high concentrated dose delivered to the tumor and the sparing of normal tissue, when compared with a course of external beam radiation therapy. (author)

  14. High and low dose-rate brachytherapy for cervical carcinoma

    International Nuclear Information System (INIS)

    Orton, C.G.

    1998-01-01

    For the brachytherapy component of the r[iation treatment of cervical carcinoma, high dose rate (HDR) is slowly replacing conventional low dose rate (LDR) due primarily to r[iation safety and other physical benefits attributed to the HDR modality. Many r[iation oncologists are reluctant to make this change because of perceived r[iobiological dis[vantages of HDR. However, in clinical practice HDR appears to be as effective as LDR but with a lower risk of late complications, as demonstrated by one randomized clinical trial and two comprehensive literature and practice surveys. The reason for this appears to be that the r[iobiological dis[vantages of HDR are outweighed by the physical [vantages. (orig.)

  15. High dose rate brachytherapy for medically inoperable stage I endometrial cancer

    Energy Technology Data Exchange (ETDEWEB)

    Petereit, Daniel G; Sarkaria, Jann N; Schink, Julian; Springman, Scott R; Kinsella, Timothy J; Buchler, Dolores A

    1995-07-01

    Purpose/Objective: To determine the efficacy of high dose rate (HDR) brachytherapy in patients with medically inoperable endometrial cancer clinically confined to the corpus. Materials and Methods: Forty-two patients with endometrial cancer and an intact uterus have been treated since 1989 with HDR brachytherapy. Twenty-six patients with medically inoperable Stage I disease were treated with radiation alone and form the basis of this study. Obesity was assessed using the body mass index (BMI kg/m{sup 2}) scale. Patients with a BMI above 28 were considered obese and those above 35 morbidly obese, per standard anesthesia guidelines. Brachytherapy was delivered in 5 HDR insertions, 1 week apart, without any external beam radiation. The following doses were delivered per insertion: 5.7 Gy to point S, 7.0 Gy to point W, 8.2 Gy to the vaginal surface and 9.2 Gy to point M. Point M represents the conventional point A dose, while points S and W are myometrial points. A single tandem with either ovoids or cylinders was placed, unless the uterine cavity would accommodate 2 tandems. All treatments were outpatient using intravenous fentanyl and midazolam for sedation. Pelvic ultrasound was commonly used at the time of brachytherapy to verify tandem placement. Three year clinical endpoints were calculated using the Kaplan Meier method. Results: The median follow-up for the study cohort was 21 months with follow-up greater than 36 months in 11 patients. Seventeen of the 26 patients were inoperable due to morbid obesity (median weight and BMI; 316 lbs and 55 kg/m{sup 2}, respectively); the other patients had poor cardiopulmonary reserve {+-} obesity. The median age, KPS (Karnofsky Performance Status), weight, ASA (American Society of Anesthesiologists' Physical Class System) and BMI were 63 yrs, 80%, 285 lbs, 3 and 49 kg/m{sup 2}, respectively. Two patients with an ASA of 3 and 4 died from acute cardio-pulmonary events within 30 days of the last insertion, emphasizing the need

  16. High dose rate brachytherapy for medically inoperable stage I endometrial cancer

    International Nuclear Information System (INIS)

    Petereit, Daniel G.; Sarkaria, Jann N.; Schink, Julian; Springman, Scott R.; Kinsella, Timothy J.; Buchler, Dolores A.

    1995-01-01

    Purpose/Objective: To determine the efficacy of high dose rate (HDR) brachytherapy in patients with medically inoperable endometrial cancer clinically confined to the corpus. Materials and Methods: Forty-two patients with endometrial cancer and an intact uterus have been treated since 1989 with HDR brachytherapy. Twenty-six patients with medically inoperable Stage I disease were treated with radiation alone and form the basis of this study. Obesity was assessed using the body mass index (BMI kg/m 2 ) scale. Patients with a BMI above 28 were considered obese and those above 35 morbidly obese, per standard anesthesia guidelines. Brachytherapy was delivered in 5 HDR insertions, 1 week apart, without any external beam radiation. The following doses were delivered per insertion: 5.7 Gy to point S, 7.0 Gy to point W, 8.2 Gy to the vaginal surface and 9.2 Gy to point M. Point M represents the conventional point A dose, while points S and W are myometrial points. A single tandem with either ovoids or cylinders was placed, unless the uterine cavity would accommodate 2 tandems. All treatments were outpatient using intravenous fentanyl and midazolam for sedation. Pelvic ultrasound was commonly used at the time of brachytherapy to verify tandem placement. Three year clinical endpoints were calculated using the Kaplan Meier method. Results: The median follow-up for the study cohort was 21 months with follow-up greater than 36 months in 11 patients. Seventeen of the 26 patients were inoperable due to morbid obesity (median weight and BMI; 316 lbs and 55 kg/m 2 , respectively); the other patients had poor cardiopulmonary reserve ± obesity. The median age, KPS (Karnofsky Performance Status), weight, ASA (American Society of Anesthesiologists' Physical Class System) and BMI were 63 yrs, 80%, 285 lbs, 3 and 49 kg/m 2 , respectively. Two patients with an ASA of 3 and 4 died from acute cardio-pulmonary events within 30 days of the last insertion, emphasizing the need for accurate pre

  17. Tumour alpha/beta ratios and dose-rate selection in brachytherapy

    International Nuclear Information System (INIS)

    Duchesne, G.M.

    2003-01-01

    Traditionally brachytherapy employed low dose rate (LDR) techniques. Recent adoption of high dose rate (HDR) applications, addressing radiation protection concerns, has sparked debate over possible reductions in therapeutic ratio. The radiobiological characteristics of two contrasting examples, prostate cancer and cervical cancer, are examined. Both in-vitro and clinical observations of prostate cancer suggest a low α/β ratio. Labelling indices are below 2.5%, translating into long potential doubling times (Tpot ) of 16 to 61 days or more. Clinical PSA doubling times are in the order of years. Analysis of clinical endpoints in prostate cancer treated with either LDR or HDR techniques indicates that its α/β ratio may lie between 1 - 4 Gy, similar to slowly proliferating late reacting tissues. As such, therapeutic gain may arise from the use of hypofractionated HDR treatments, exploiting the sensitivity to large fraction sizes, effectively escalating dose. The slow proliferative rate also gives credence to the use of LDR, although several tumour doublings may occur during the effective treatment time, and analysis of the clinical data using a low α/β ratio suggests that LDR doses are only equivalent to 70 Gy with conventional fractionation. Cervical carcinoma is a rapidly proliferating tumour with Tpot values of 3-6 days. LDR implants were delivered over relatively short treatment times, negating repopulation effects, and the 'hyperfractionation' effect of LDR was suited to the high α/β ratio. HDR, although also preventing significant repopulation, has the potential to decrease the therapeutic ratio if low α/β , late-reacting tissues are not protected. Clinical data however show improved outcomes and reduced morbidity with HDR through reduced doses to normal tissues. Choosing the optimal dose rate in brachytherapy depends on tumour behaviour and achievable accuracy. HDR offers some advantages even for high α/β ratio tumours, and may be the technique of

  18. Fractionated high dose rate intraluminal brachytherapy in palliation of advanced esophageal cancer

    International Nuclear Information System (INIS)

    Sur, Ranjan K.; Donde, Bernard; Levin, Victor C.; Mannell, Aylwyn

    1998-01-01

    Purpose: To optimize the dose of fractionated brachytherapy for palliation of advanced esophageal cancer. Methods and Materials: One hundred and seventy-two patients with advanced esophageal cancer were randomized to receive 12 Gy/2 fractions (group A); 16 Gy/2 fractions (group B), and 18 Gy/3 fractions (group C) by high dose rate intraluminal brachytherapy (HDRILBT). Treatment was given weekly and dose prescribed at 1 cm from the source axis. Patients were followed up monthly and assessed for dysphagia relief and development of complications. Results: Twenty-two patients died before completing treatment due to advanced disease and poor general condition. The overall survival was 19.4% at the end of 12 months for the whole group (A--9.8%, B--22.46%, C--35.32%; p > 0.05). The dysphagia-free survival was 28.9% at 12 months for the whole group (A--10.8%, B--25.43%, C--38.95%; p > 0.05). Forty-three patients developed fibrotic strictures needing dilatation (A--5 of 35, B--15 of 60, C--23 of 55; p = 0.032). Twenty-seven patients had persistent luminal disease (A--11, B--6, C--10), 15 of which progressed to fistulae (A--7, B--2, C--6; p = 0.032). There was no effect of age, sex, race, histology, performance status, previous dilation, presenting dysphagia score, presenting weight, grade, tumor length, and stage on overall survival, dysphagia-free, and complication-free survival (p > 0.05). On a multivariate analysis, brachytherapy dose (p = 0.002) and tumor length (p = 0.0209) were found to have a significant effect on overall survival; brachytherapy dose was the only factor that had an impact on local tumor control (p = 0.0005), while tumor length was the only factor that had an effect on dysphagia-free survival (p = 0.0475). When compared to other forms of palliation currently available (bypass surgery, laser, chemotherapy, intubation, external radiotherapy), fractionated brachytherapy gave the best results with a median survival of 6.2 months. Conclusions: Fractionated

  19. Estimation of the transit dose component in high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Garcia Romero, A.; Millan Cebrian, E.; Lozano Flores, F.J.; Lope Lope, R.; Canellas Anoz, M.

    2001-01-01

    Current high dose rate brachytherapy (HDR) treatment planning systems usually calculate dose only from source stopping positions (stationary component), but fails to account for the administered dose when the source is moving (dynamic component or transit dose). Numerical values of this transit dose depends upon the source velocity, implant geometry, source activity and prescribed dose. In some HDR treatments using particular geometry the transit dose cannot be ignored because it increases the dose at the prescriptions points and also could increase potential late tissue complications as predicted by the linear quadratic model. International protocols recommend to verify this parameter. The aim of this paper has been to establish a procedure for the transit dose calculation for the Gammamed 12i equipment at the RT Department in the Clinical University Hospital (Zaragoza-Spain). A numeric algorithm was implemented based on a dynamic point approximation for the moving HDR source and the calculated results for the entrance-exit transit dose was compared with TLD measurements made in some discrete points. (author) [es

  20. Perioperative high dose rate (HDR brachytherapy in unresectable locally advanced pancreatic tumors

    Directory of Open Access Journals (Sweden)

    Brygida Białas

    2011-07-01

    Full Text Available Purpose: The aim of the study was to present an original technique of catheter implantation for perioperative HDR-Ir192 brachytherapy in patients after palliative operations of unresectable locally advanced pancreatic tumors and to estimate the influence of perioperative HDR-Ir192 brachytherapy on pain relief in terminal pancreatic cancer patients. Material and methods: Eight patients with pancreatic tumors located in the head of pancreas underwent palliative operations with the use of HDR-Ir192 brachytherapy. All patients qualified for surgery reported pain of high intensity and had received narcotic painkillers prior to operation. During the last phase of the surgery, the Nucletron® catheters were implanted in patients to prepare them for later perioperative brachytherapy. Since the 6th day after surgery HDR brachytherapy was performed. Before each brachytherapy fraction the location of implants were checked using fluoroscopy. A fractional dose was 5 Gy and a total dose was 20 Gy in the area of radiation. A comparative study of two groups of patients (with and without brachytherapy with stage III pancreatic cancer according to the TNM scale was taken in consideration. Results and Conclusions: The authors claim that the modification of catheter implantation using specially designed cannula, facilitates the process of inserting the catheter into the tumor, shortens the time needed for the procedure, and reduces the risk of complications. Mean survival time was 5.7 months. In the group of performed brachytherapy, the mean survival time was 6.7 months, while in the group of no brachytherapy performed – 4.4 months. In the group of brachytherapy, only one patient increased the dose of painkillers in the last month of his life. Remaining patients took constant doses of medicines. Perioperative HDR-Ir192 brachytherapy could be considered as a practical application of adjuvant therapy for pain relief in patients with an advanced pancreatic cancer.

  1. Late effects of post-high-dose-rate brachytherapy for oropharyngeal carcinoma: are they severer than post-low-dose-rate?

    International Nuclear Information System (INIS)

    Nose, T.; Koizumi, M.; Nishiyama, K.; Peiffert, D.; Lapeyre, M.; Hoffstetter, S.

    2004-01-01

    Background: late effects by high-dose-rate (HDR) brachytherapy have been believed severer than low-dose-rate (LDR) provided tumor control was constant. Local control of oropharyngeal carcinoma with HDR at Osaka Medical Center was comparable to LDR series from Centre Alexis Vautrin (82%, 79.5%, respectively). To assess the feasibility of HDR brachytherapy, the late effects were compared. Patients and methods: the data of 29 HDR and 24 LDR patients (median follow-up of 27 and 29.5 months, respectively; p = 0.89) were collected. The HDR schedule was 21 Gy/3.5 fractions/2 days following 46 Gy/23 fractions external beam, while 25 Gy/3 days following 50 Gy/25 fractions external beam was for LDR. Late changes were evaluated using RTOG/EORTC late morbidity scoring scheme. For subclinical late changes, mucosa chapter of Dische score was modified for brachytherapy. Scores were discussed through photos and were agreed on by authors. Late sequelae were estimated, by reviewing charts, concerning frequency, severity, and duration of mucosal damages (erosion and ulcer). Results: Late changes were of no difference (p = 0.12 for EORTC/RTOG, and p = 0.45, 0.47, 1.00, 0.12, 0.16, 0.95, 0.27, 0.21 for erythema, ulceration, edema, thinning, pallor, telangiectasia, mobility impairment of tongue/faucial pillars, respectively, of the modified Dische score). Late sequelae showed no differences (p = 0.90, 0.12, 0.40 for frequency, severity, duration, respectively, of mucosal damages). Conclusion: the late effects by HDR were not severer than by LDR. HDR oropharyngeal brachytherapy is as safe as LDR. (orig.)

  2. High-dose-rate versus low-dose-rate brachytherapy in the treatment of cervical cancer: analysis of tumor recurrence - the University of Wisconsin experience

    International Nuclear Information System (INIS)

    Petereit, Daniel G.; Sarkaria, Jann N.; Potter, David M.; Schink, Julian C.

    1999-01-01

    Purpose: To retrospectively compare the clinical outcome for cervical cancer patients treated with high-dose-rate (HDR) vs. low-dose-rate (LDR) brachytherapy. Methods and Materials: One hundred ninety-one LDR patients were treated from 1977 to 1988 and compared to 173 HDR patients treated from 1989 to 1996. Patients of similar stage and tumor volumes were treated with identical external beam fractionation schedules. Brachytherapy was given in either 1 or 2 LDR implants for the earlier patient cohort, and 5 HDR implants for the latter cohort. For both patient groups, Point A received a minimum total dose of 80 Gy. The linear-quadratic formula was used to calculate the LDR dose-equivalent contribution to Point A for the HDR treatments. The primary endpoints assessed were survival, pelvic control, relapse-free survival, and distant metastases. Endpoints were estimated using the Kaplan-Meier method. Comparisons between treatment groups were performed using the log-rank test and Cox proportional hazards models. Results: The median follow-up was 65 months (2 to 208 months) in the LDR group and 22 months (1 to 85 months) in the HDR group. For all stages combined there was no difference in survival, pelvic control, relapse-free survival, or distant metastases between LDR and HDR patients. For Stage IB and II HDR patients, the pelvic control rates were 85% and 80% with survival rates of 86% and 65% at 3 years, respectively. In the LDR group, Stage IB and II patients had 91% and 78% pelvic control rates, with 82% and 58% survival rates at 3 years, respectively. No difference was seen in survival or pelvic control for bulky Stage I and II patients combined (> 5 cm). Pelvic control at 3 years was 44% (HDR) versus 75% (LDR) for Stage IIIB patients (p = 0.002). This difference in pelvic control was associated with a lower survival rate in the Stage IIIB HDR versus LDR population (33% versus 58%, p = 0.004). The only major difference, with regard to patient characteristics

  3. Quality control in pulsed dose rate brachytherapy; Controle de qualite en curietherapie de debit de dose pulse

    Energy Technology Data Exchange (ETDEWEB)

    Metayer, Y.; Brunaud, C.; Peiffert, D. [Centre Alexis-Vautrin, Unite de Radiophysique, 54 - Vandoeuvre-les-Nancy (France); Meyer, P. [Centre Paul-Strauss, 67 - Strasbourg (France)

    2009-07-15

    A prospective multicenter study (P.D.R.) was leaded on pulsed dose rate brachytherapy over 2 years (2005/2006) in 20 French centres, as part of a programme entitled (Support for the innovative and expensive techniques) S.t.i.c.-P.D.R. and supported by the French ministry of health. Eight hundred and fifty patients were treated for cervix carcinoma with 2D classic or 3D innovative brachytherapy (425 in each arm). The main objectives of this study were to assess the cost of P.D.R. brachytherapy with dose optimization compared to traditional treatments, and to evaluate the complications and local control. A joint programme of quality control was established by the physicists of the different centres, concerning the software treatment planning, the source replacement, the projector and the technical parameters of the course of patient treatment. This technical note lists these controls, and their frequency. (authors)

  4. Dose rate constant and energy spectrum of interstitial brachytherapy sources

    International Nuclear Information System (INIS)

    Chen Zhe; Nath, Ravinder

    2001-01-01

    In the past two years, several new manufacturers have begun to market low-energy interstitial brachytherapy seeds containing 125 I and 103 Pd. Parallel to this development, the National Institute of Standards and Technology (NIST) has implemented a modification to the air-kerma strength (S K ) standard for 125 I seeds and has also established an S K standard for 103 Pd seeds. These events have generated a considerable number of investigations on the determination of the dose rate constants (Λ) of interstitial brachytherapy seeds. The aim of this work is to study the general properties underlying the determination of Λ and to develop a simple method for a quick and accurate estimation of Λ. As the dose rate constant of clinical seeds is defined at a fixed reference point, we postulated that Λ may be calculated by treating the seed as an effective point source when the seed's source strength is specified in S K and its source characteristics are specified by the photon energy spectrum measured in air at the reference point. Using a semi-analytic approach, an analytic expression for Λ was derived for point sources with known photon energy spectra. This approach enabled a systematic study of Λ as a function of energy. Using the measured energy spectra, the calculated Λ for 125 I model 6711 and 6702 seeds and for 192 Ir seed agreed with the AAPM recommended values within ±1%. For the 103 Pd model 200 seed, the agreement was 5% with a recently measured value (within the ±7% experimental uncertainty) and was within 1% with the Monte Carlo simulations. The analytic expression for Λ proposed here can be evaluated using a programmable calculator or a simple spreadsheet and it provides an efficient method for checking the measured dose rate constant for any interstitial brachytherapy seed once the energy spectrum of the seed is known

  5. Local vaginal anesthesia during high-dose-rate intracavitary brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Chen, H.-C.; Wan Leung, Stephen; Wang, C.-J.; Sun, L.-M.; Fang, F.-M.; Huang, E.-Y.; Wang, S.-J.; Yang, C.-W.

    1998-01-01

    Purpose: To evaluate the clinical efficacy of local vaginal lidocaine application for pain relief during high-dose-rate (HDR) intracavitary brachytherapy for patients with cervical cancer, and to investigate sequential changes in serum levels of lidocaine during the procedures. Methods and Materials: This prospective study was designed to examine the analgesic effect, physical response, and side effects of local anesthesia during HDR intracavitary brachytherapy. Forty patients were enrolled. All patients received 10-15 MV X-rays to the pelvis with a total dose of 45-59.4 Gy 5-6 weeks before undergoing HDR intracavitary brachytherapy. All patients underwent first intracavitary brachytherapy under general anesthesia. These patients were randomly allocated to receive one of two different treatment protocols as follows: (1) treatment session - control session - treatment session - control session; or (2) control session - treatment session- control session - treatment session. In the treatment sessions, topical anesthesia was administered using 4 ml of 10% lidocaine solution sprayed liberally on the cervix and vagina during intracavitary brachytherapy. In the control sessions, a placebo was administered in the same manner during brachytherapy. The Hensche's applicators for brachytherapy were inserted into the cervix and vagina 5 min after lidocaine application. The visual analogue scale (VAS) was used to assess pain and discomfort during brachytherapy. Blood pressure and heart rates were measured to evaluate the physiological response. Another prospective study was then performed to investigate the sequential changes of serum lidocaine levels during the anesthetic procedure. Eleven additional patients with similar disease state and demographic characteristics were enrolled and blood samples were obtained before, and 5, 15, 30, and 45 min after the initiation of lidocaine application. Results: The mean VAS values recorded during the treatment sessions and control

  6. Dosimetric Effects of Air Pockets Around High-Dose Rate Brachytherapy Vaginal Cylinders

    International Nuclear Information System (INIS)

    Richardson, Susan; Palaniswaamy, Geethpriya; Grigsby, Perry W.

    2010-01-01

    Purpose: Most physicians use a single-channel vaginal cylinder for postoperative endometrial cancer brachytherapy. Recent published data have identified air pockets between the vaginal cylinders and the vaginal mucosa. The purpose of this research was to evaluate the incidence, size, and dosimetric effects of these air pockets. Methods and Materials: 25 patients receiving postoperative vaginal cuff brachytherapy with a high-dose rate vaginal cylinders were enrolled in this prospective data collection study. Patients were treated with 6 fractions of 200 to 400 cGy per fraction prescribed at 5 mm depth. Computed tomography simulation for brachytherapy treatment planning was performed for each fraction. The quantity, volume, and dosimetric impact of the air pockets surrounding the cylinder were quantified. Results: In 25 patients, a total of 90 air pockets were present in 150 procedures (60%). Five patients had no air pockets present during any of their treatments. The average number of air pockets per patient was 3.6, with the average total air pocket volume being 0.34 cm 3 (range, 0.01-1.32 cm 3 ). The average dose reduction to the vaginal mucosa at the air pocket was 27% (range, 9-58%). Ten patients had no air pockets on their first fraction but air pockets occurred in subsequent fractions. Conclusion: Air pockets between high-dose rate vaginal cylinder applicators and the vaginal mucosa are present in the majority of fractions of therapy, and their presence varies from patient to patient and fraction to fraction. The existence of air pockets results in reduced radiation dose to the vaginal mucosa.

  7. Perioperative Interstitial High-Dose-Rate Brachytherapy for the Treatment of Recurrent Keloids

    DEFF Research Database (Denmark)

    Jiang, Ping; Baumann, René; Dunst, Jürgen

    2016-01-01

    PURPOSE: To prospectively evaluate high-dose-rate brachytherapy in the treatment of therapy-resistant keloids and report first results, with emphasis on feasibility and early treatment outcome. METHODS AND MATERIALS: From 2009 to 2014, 24 patients with 32 recurrent keloids were treated with immed...

  8. Radiobiological equivalent of low/high dose rate brachytherapy and evaluation of tumor and normal responses to the dose.

    Science.gov (United States)

    Manimaran, S

    2007-06-01

    The aim of this study was to compare the biological equivalent of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy in terms of the more recent linear quadratic (LQ) model, which leads to theoretical estimation of biological equivalence. One of the key features of the LQ model is that it allows a more systematic radiobiological comparison between different types of treatment because the main parameters alpha/beta and micro are tissue-specific. Such comparisons also allow assessment of the likely change in the therapeutic ratio when switching between LDR and HDR treatments. The main application of LQ methodology, which focuses on by increasing the availability of remote afterloading units, has been to design fractionated HDR treatments that can replace existing LDR techniques. In this study, with LDR treatments (39 Gy in 48 h) equivalent to 11 fractions of HDR irradiation at the experimental level, there are increasing reports of reproducible animal models that may be used to investigate the biological basis of brachytherapy and to help confirm theoretical predictions. This is a timely development owing to the nonavailability of sufficient retrospective patient data analysis. It appears that HDR brachytherapy is likely to be a viable alternative to LDR only if it is delivered without a prohibitively large number of fractions (e.g., fewer than 11). With increased scientific understanding and technological capability, the prospect of a dose equivalent to HDR brachytherapy will allow greater utilization of the concepts discussed in this article.

  9. DuraSeal® as a spacer to reduce rectal doses in low-dose rate brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Heikkilä, Vesa-Pekka; Kärnä, Aarno; Vaarala, Markku H.

    2014-01-01

    The purpose of this study was to evaluate the utility of off-label use of DuraSeal® polyethylene glycol (PEG) gel in low-dose rate (LDR) prostate brachytherapy seed implantation to reduce rectal doses. Diluted DuraSeal® was easy to use and, in spite of a clearance effect, useful in decreasing D 2cc rectal doses

  10. Medium dose rate brachytherapy for patients with cervical carcinoma; early result of a prospective study

    Directory of Open Access Journals (Sweden)

    Amouzegar Hashemi F

    2009-03-01

    Full Text Available "nBackground: Treatment of cervical carcinoma is routinely performed with Low Dose Rate (LDR brachytherapy, but Brachytherapy in our department is done with Medium Dose Rate (MDR due to the technical characteristics of the machine available here. Thus we decided to evaluate the results of this treatment in our department in a prospective study. "nMethods: Between March 2006 and July 2008, 140 patients with histologic diagnosis of cervical carcinoma referred to Tehran Cancer Institute; were treated with external beam radiotherapy (44-64 Gy to whole pelvis and MDR brachytherapy (8-30 Gy to Point A with a dose rate of 2.2±0.3 Gy/h. "nResults: 121 patients were followed up for a median time of 18 months (range: 9-39 m. There were 11%(6/54 local recurrence for surgery and adjuvant radiotherapy group; 25%(16/65 for radical radiotherapy group, and 19%(23/121 for all patients. Rectal and bladder complications incidence for all patients were 10%(12/121 and 13%(16/121 respectively. High grade complication was shown only in one patient in radical radiotherapy group. In this study 3-years disease free survival and overall survival were 73% and 92% respectively, and disease stage (p=0.007 and overall treatment time (p=0.05 were the significant factors affecting disease free survival. "nConclusions: Results of this series suggest that the use of external beam radiotherapy and MDR brachytherapy with about 20% dose reduction in comparison with LDR can be an acceptable technique with regard to local control and complications.

  11. Fitting and benchmarking of Monte Carlo output parameters for iridium-192 high dose rate brachytherapy source

    International Nuclear Information System (INIS)

    Acquah, F.G.

    2011-01-01

    Brachytherapy, the use of radioactive sources for the treatment of tumours is an important tool in radiation oncology. Accurate calculations of dose delivered to malignant and normal tissues are the main responsibility of the Medical Physics staff. With the use of Treatment Planning System (TPS) computers now becoming a standard practice in the Radiation Oncology Departments, Independent calculations to certify the results of these commercial TPSs are important part of a good quality management system for brachytherapy implants. There are inherent errors in the dose distributions produced by these TPSs due to its failure to account for heterogeneity in the calculation algorithms and Monte Carlo (MC) method seems to be the panacea for these corrections. In this study, a fit functional form using MC output parameters was performed to reduce dose calculation uncertainty using the Matlab software curve fitting applications. This includes the modification of the AAPM TG-43 parameters to accommodate the new developments for a rapid brachytherapy dose rate calculation. Analytical computations were performed to hybridize the anisotropy function, F(r,θ) and radial dose function, g(r) into a single new function f(r,θ) for the Nucletron microSelectron High Dose Rate 'new or v2' (mHDRv2) 192 Ir brachytherapy source. In order to minimize computation time and to improve the accuracy of manual calculations, the dosimetry function f(r,θ) used fewer parameters and formulas for the fit. Using MC outputs as the standard, the percentage errors for the fits were calculated and used to evaluate the average and maximum uncertainties. Dose rate deviation between the MC data and fit were also quantified as errors(E), which showed minimal values. These results showed that the dosimetry parameters from this study as compared to those of MC outputs parameters were in good agreement and better than the results obtained from literature. The work confirms a lot of promise in building robust

  12. Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ruijie, E-mail: ruijyang@yahoo.com; Zhao, Nan; Liao, Anyan; Wang, Hao; Qu, Ang

    2016-10-01

    To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5 mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78 Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D{sub 90} of 34 Gy in 8.5 Gy per fraction, and 145 Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2 Gy per fraction, EQD{sub 2}) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The D{sub mean} (EQD{sub 2}) of rectum decreased 22.36 Gy in HDR and 17.01 Gy in LDR from 30.24 Gy in VMAT, respectively. The D{sub mean} (EQD{sub 2}) of bladder decreased 6.91 Gy in HDR and 2.53 Gy in LDR from 13.46 Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD{sub 2}) was 80.26, 70.23, and 104.91 Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR.

  13. Dosimetric and radiobiological comparison of volumetric modulated arc therapy, high-dose rate brachytherapy, and low-dose rate permanent seeds implant for localized prostate cancer

    International Nuclear Information System (INIS)

    Yang, Ruijie; Zhao, Nan; Liao, Anyan; Wang, Hao; Qu, Ang

    2016-01-01

    To investigate the dosimetric and radiobiological differences among volumetric modulated arc therapy (VMAT), high-dose rate (HDR) brachytherapy, and low-dose rate (LDR) permanent seeds implant for localized prostate cancer. A total of 10 patients with localized prostate cancer were selected for this study. VMAT, HDR brachytherapy, and LDR permanent seeds implant plans were created for each patient. For VMAT, planning target volume (PTV) was defined as the clinical target volume plus a margin of 5 mm. Rectum, bladder, urethra, and femoral heads were considered as organs at risk. A 78 Gy in 39 fractions were prescribed for PTV. For HDR and LDR plans, the dose prescription was D 90 of 34 Gy in 8.5 Gy per fraction, and 145 Gy to clinical target volume, respectively. The dose and dose volume parameters were evaluated for target, organs at risk, and normal tissue. Physical dose was converted to dose based on 2-Gy fractions (equivalent dose in 2 Gy per fraction, EQD 2 ) for comparison of 3 techniques. HDR and LDR significantly reduced the dose to rectum and bladder compared with VMAT. The D mean (EQD 2 ) of rectum decreased 22.36 Gy in HDR and 17.01 Gy in LDR from 30.24 Gy in VMAT, respectively. The D mean (EQD 2 ) of bladder decreased 6.91 Gy in HDR and 2.53 Gy in LDR from 13.46 Gy in VMAT. For the femoral heads and normal tissue, the mean doses were also significantly reduced in both HDR and LDR compared with VMAT. For the urethra, the mean dose (EQD 2 ) was 80.26, 70.23, and 104.91 Gy in VMAT, HDR, and LDR brachytherapy, respectively. For localized prostate cancer, both HDR and LDR brachytherapy were clearly superior in the sparing of rectum, bladder, femoral heads, and normal tissue compared with VMAT. HDR provided the advantage in sparing of urethra compared with VMAT and LDR.

  14. Toward endobronchial Ir-192 high-dose-rate brachytherapy therapeutic optimization

    International Nuclear Information System (INIS)

    Gay, H A; Allison, R R; Downie, G H; Mota, H C; Austerlitz, C; Jenkins, T; Sibata, C H

    2007-01-01

    A number of patients with lung cancer receive either palliative or curative high-dose-rate (HDR) endobronchial brachytherapy. Up to a third of patients treated with endobronchial HDR die from hemoptysis. Rather than accept hemoptysis as an expected potential consequence of HDR, we have calculated the radial dose distribution for an Ir-192 HDR source, rigorously examined the dose and prescription points recommended by the American Brachytherapy Society (ABS), and performed a radiobiological-based analysis. The radial dose rate of a commercially available Ir-192 source was calculated with a Monte Carlo simulation. Based on the linear quadratic model, the estimated palliative, curative and blood vessel rupture radii from the center of an Ir-192 source were obtained for the ABS recommendations and a series of customized HDR prescriptions. The estimated radius at risk for blood vessel perforation for the ABS recommendations ranges from 7 to 9 mm. An optimized prescription may in some situations reduce this radius to 4 mm. The estimated blood perforation radius is generally smaller than the palliative radius. Optimized and individualized endobronchial HDR prescriptions are currently feasible based on our current understanding of tumor and normal tissue radiobiology. Individualized prescriptions could minimize complications such as fatal hemoptysis without sacrificing efficacy. Fiducial stents, HDR catheter centering or spacers and the use of CT imaging to better assess the relationship between the catheter and blood vessels promise to be useful strategies for increasing the therapeutic index of this treatment modality. Prospective trials employing treatment optimization algorithms are needed

  15. Curative high dose rate vaginal apex brachytherapy in stage I papillary serous carcinoma of the endometrium

    International Nuclear Information System (INIS)

    Turner, B.C.; Kacinski, B.M.; Gumbs, A.; Peschel, R.E.; Haffty, B.G.; Wilson, L.D.

    1996-01-01

    Introduction: Uterine papillary serous carcinoma (UPSC) is a morphologically distinct variant of endometrial carcinoma that is associated with a poor prognosis, high recurrence rate, clinical understaging, and poor response to salvage treatment. We describe the presentation, local and distant control, survival, salvage rate, and complications for patients undergoing whole abdominal radiation therapy (WART), low dose rate (LDR) intracavitary brachytherapy, or high dose rate (HDR) vaginal brachytherapy in patients with stage I UPSC. Methods: Between 1976 and 1994 more than 1700 patients with endometrial carcinoma were treated with radiation therapy, 30 patients with stage I UPSC (1.8%) were treated with radiation before or following TAH/BSO. All patients underwent either preoperative Simon's packing or tandem and plaque which delivered 30-40 Gy to the serosa, WART, or HDR Ir-192 vaginal apex brachytherapy to a total dose of 21 Gy in 3 fractions at 0.5 cm from the vaginal mucosa. A total of 14 patients received HDR vaginal brachytherapy and (5(14)) patients received systemic chemotherapy. All patients presented with vaginal bleeding at a median age of 67 years (range 34-88). The group of 30 patients underwent TAH/BSO, 17 patients were completely staged pathologically (pelvic and para-aortic lymph nodes, omentectomy, and pelvic washings), and 2 patients underwent omental biopsy and pelvic washings only. All specimens revealed UPSC, nuclear grade 3, and lymphovascular invasion (23%). The pathologic stage was IA: 23% (7), IB: 67% (20), and IC: 10% (3). The median follow-up for all patients was 49 months (range 13-187 months). For the patients receiving postoperative HDR vaginal brachytherapy the median time from surgery to radiation was 42 days (range 29-91). Results: The 5-year actuarial disease free survival for Figo stage I UPSC patients treated with postoperative HDR vaginal brachytherapy and systemic chemotherapy was 100% compared to 74% for stage I UPSC patient

  16. Low-Dose-Rate Brachytherapy Versus Cryotherapy in Low- and Intermediate-Risk Prostate Cancer

    International Nuclear Information System (INIS)

    Gestaut, Matthew M.; Cai, Wendi; Vyas, Shilpa; Patel, Belur J.; Hasan, Salman A.; MunozMaldonado, Yolanda; Deb, Niloyjyoti; Swanson, Gregory

    2017-01-01

    Purpose: Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single-institution retrospective studies. Currently, no published evidence has compared low-dose-rate brachytherapy versus cryotherapy. Methods and Materials: Institutional review board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990 to 2012. For inclusion, patients must have received a prostate cancer diagnosis and have been considered to have low- to intermediate-risk disease according to the National Comprehensive Cancer Network criteria. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2 ng/mL. Results: A total of 359 patients were analyzed. The groups comprised 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. The median prostate-specific antigen follow-up periods were 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression–free survival (bPFS) rate was 57.9% in the cryotherapy group versus 89.6% in the brachytherapy group (P<.0001). The 5-year bPFS rate was 70.0% (LRC), 51.4% (IRC), 89.4% (LRB), and 89.7% (IRB). The bPFS rate was significantly different between brachytherapy and cryotherapy for low- and intermediate-risk groups (P<.05). The mean nadir temperature reached for cryotherapy patients was −35°C (range, −96°C to −6°C). Cryotherapy used a median of 2 freeze-thaw cycles (range, 2-4 freeze-thaw cycles). Conclusions: Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with

  17. Low-Dose-Rate Brachytherapy Versus Cryotherapy in Low- and Intermediate-Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gestaut, Matthew M., E-mail: Matthew.Gestaut@BSWHealth.org [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); Cai, Wendi [Department of Biostatistics, Baylor Scott and White Health, Temple, Texas (United States); Vyas, Shilpa [Department of Radiation Oncology, Swedish Cancer Institute, Seattle, Washington (United States); Patel, Belur J. [Department of Urology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); Hasan, Salman A. [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States); MunozMaldonado, Yolanda [Department of Biostatistics, Baylor Scott and White Health, Temple, Texas (United States); Deb, Niloyjyoti; Swanson, Gregory [Department of Radiation Oncology, Baylor Scott and White Memorial Hospital, Texas A& M University School of Medicine, Temple, Texas (United States)

    2017-05-01

    Purpose: Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single-institution retrospective studies. Currently, no published evidence has compared low-dose-rate brachytherapy versus cryotherapy. Methods and Materials: Institutional review board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990 to 2012. For inclusion, patients must have received a prostate cancer diagnosis and have been considered to have low- to intermediate-risk disease according to the National Comprehensive Cancer Network criteria. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2 ng/mL. Results: A total of 359 patients were analyzed. The groups comprised 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. The median prostate-specific antigen follow-up periods were 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression–free survival (bPFS) rate was 57.9% in the cryotherapy group versus 89.6% in the brachytherapy group (P<.0001). The 5-year bPFS rate was 70.0% (LRC), 51.4% (IRC), 89.4% (LRB), and 89.7% (IRB). The bPFS rate was significantly different between brachytherapy and cryotherapy for low- and intermediate-risk groups (P<.05). The mean nadir temperature reached for cryotherapy patients was −35°C (range, −96°C to −6°C). Cryotherapy used a median of 2 freeze-thaw cycles (range, 2-4 freeze-thaw cycles). Conclusions: Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with

  18. Pulsed dose rate (PDR) brachytherapy as salvage treatment of locally advanced or recurrent gynecologic cancer

    DEFF Research Database (Denmark)

    Jensen, P T; Roed, H; Engelholm, S A

    1998-01-01

    PURPOSE: Pulsed dose rate (PDR) brachytherapy is a new treatment option permitting dose distribution optimization in interstitial implants. It possesses the advantage of equipment simplification and radiation protection to the staff, compared to the manually afterloading technique. This study pre...

  19. Perioperative Interstitial High-Dose-Rate Brachytherapy for the Treatment of Recurrent Keloids: Feasibility and Early Results

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Ping, E-mail: ping.jiang@uksh.de [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Baumann, René [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Dunst, Juergen [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Department of Radiation Oncology, University of Copenhagen, Copenhagen (Denmark); Geenen, Matthias [Department of Reconstructive Surgery, Lubinus Clinic Kiel, Kiel (Germany); Siebert, Frank-André [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Niehoff, Peter [Department of Radiation Oncology, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany); Department of Radiation Oncology, Community Clinic Köln, Köln (Germany); Department of Radiation Oncology, University Witten/Herdecke, Witten (Germany); Bertolini, Julia; Druecke, Daniel [Department of Reconstructive Surgery, University Clinic Schleswig-Holstein, Campus Kiel, Kiel (Germany)

    2016-03-01

    Purpose: To prospectively evaluate high-dose-rate brachytherapy in the treatment of therapy-resistant keloids and report first results, with emphasis on feasibility and early treatment outcome. Methods and Materials: From 2009 to 2014, 24 patients with 32 recurrent keloids were treated with immediate perioperative high-dose-rate brachytherapy; 3 patients had been previously treated with adjuvant external beam radiation therapy and presented with recurrences in the pretreated areas. Two or more different treatment modalities had been tried in all patients and had failed to achieve remission. After (re-)excision of the keloids, a single brachytherapy tube was placed subcutaneously before closing the wound. The target volume covered the scar in total length. Brachytherapy was given in 3 fractions with a single dose of 6 Gy in 5 mm tissue depth. The first fraction was given within 6 hours after surgery, the other 2 fractions on the first postoperative day. Thus, a total dose of 18 Gy in 3 fractions was administered within 36 hours after the resection. Results: The treatment was feasible in all patients. No procedure-related complications (eg, secondary infections) occurred. Nineteen patients had keloid-related symptoms before treatment like pain and pruritus; disappearance of symptoms was noticed in all patients after treatment. After a median follow-up of 29.4 months (range, 7.9-72.4 months), 2 keloid recurrences and 2 mildly hypertrophied scars were observed. The local control rate was 94%. Pigmentary abnormalities were detected in 3 patients, and an additional 6 patients had a mild delay in the wound-healing process. Conclusions: The early results of this study prove the feasibility and the efficacy of brachytherapy for the prevention of keloids. The results also suggest that brachytherapy may be advantageous in the management of high-risk keloids or as salvage treatment for failure after external beam therapy.

  20. Applicability and dosimetric impact of ultrasound-based preplanning in high-dose-rate brachytherapy of prostate cancer

    International Nuclear Information System (INIS)

    Aebersold, D.M.; Isaak, B.; Behrensmeier, F.; Kolotas, C.; Mini, R.; Greiner, R.H.; Thalmann, G.; Kranzbuehler, H.

    2004-01-01

    Background and purpose: analyses of permanent brachytherapy seed implants of the prostate have demonstrated that the use of a preplan may lead to a considerable decrease of dosimetric implant quality. The authors aimed to determine whether the same drawbacks of preplanning also apply to high-dose-rate (HDR) brachytherapy. Patients and methods: 15 patients who underwent two separate HDR brachytherapy implants in addition to external-beam radiation therapy for advanced prostate cancer were analyzed. A pretherapeutic transrectal ultrasound was performed in all patients to generate a preplan for the first brachytherapy implant. For the second brachytherapy, a subset of patients were treated by preplans based on the ultrasound from the first brachytherapy implant. Preplans were compared with the respective postplans assessing the following parameters: coverage index, minimum target dose, homogeneity index, and dose exposure of organs at risk. The prostate geometries (volume, width, height, length) were compared as well. Results: at the first brachytherapy, the matching between the preplan and actual implant geometry was sufficient in 47% of the patients, and the preplan could be applied. The dosimetric implant quality decreased considerably: the mean coverage differed by -0.11, the mean minimum target dose by -0.15, the mean homogeneity index by -0.09. The exposure of organs at risk was not substantially altered. At the second brachytherapy, all patients could be treated by the preplan; the differences between the implant quality parameters were less pronounced. The changes of prostate geometry between preplans and postplans were considerable, the differences in volume ranging from -8.0 to 13.8 cm 3 and in dimensions (width, height, length) from -1.1 to 1.0 cm. Conclusion: preplanning in HDR brachytherapy of the prostate is associated with a substantial decrease of dosimetric implant quality, when the preplan is based on a pretherapeutic ultrasound. The implant quality

  1. Time-driven activity-based costing of low-dose-rate and high-dose-rate brachytherapy for low-risk prostate cancer.

    Science.gov (United States)

    Ilg, Annette M; Laviana, Aaron A; Kamrava, Mitchell; Veruttipong, Darlene; Steinberg, Michael; Park, Sang-June; Burke, Michael A; Niedzwiecki, Douglas; Kupelian, Patrick A; Saigal, Christopher

    Cost estimates through traditional hospital accounting systems are often arbitrary and ambiguous. We used time-driven activity-based costing (TDABC) to determine the true cost of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy for prostate cancer and demonstrate opportunities for cost containment at an academic referral center. We implemented TDABC for patients treated with I-125, preplanned LDR and computed tomography based HDR brachytherapy with two implants from initial consultation through 12-month followup. We constructed detailed process maps for provision of both HDR and LDR. Personnel, space, equipment, and material costs of each step were identified and used to derive capacity cost rates, defined as price per minute. Each capacity cost rate was then multiplied by the relevant process time and products were summed to determine total cost of care. The calculated cost to deliver HDR was greater than LDR by $2,668.86 ($9,538 vs. $6,869). The first and second HDR treatment day cost $3,999.67 and $3,955.67, whereas LDR was delivered on one treatment day and cost $3,887.55. The greatest overall cost driver for both LDR and HDR was personnel at 65.6% ($4,506.82) and 67.0% ($6,387.27) of the total cost. After personnel costs, disposable materials contributed the second most for LDR ($1,920.66, 28.0%) and for HDR ($2,295.94, 24.0%). With TDABC, the true costs to deliver LDR and HDR from the health system perspective were derived. Analysis by physicians and hospital administrators regarding the cost of care afforded redesign opportunities including delivering HDR as one implant. Our work underscores the need to assess clinical outcomes to understand the true difference in value between these modalities. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  2. Determination of the tissue inhomogeneity correction in high dose rate Brachytherapy for Iridium-192 source

    Directory of Open Access Journals (Sweden)

    Barlanka Ravikumar

    2012-01-01

    Full Text Available In Brachytherapy treatment planning, the effects of tissue heterogeneities are commonly neglected due to lack of accurate, general and fast three-dimensional (3D dose-computational algorithms. In performing dose calculations, it is assumed that the tumor and surrounding tissues constitute a uniform, homogeneous medium equivalent to water. In the recent past, three-dimensional computed tomography (3D-CT based treatment planning for Brachytherapy applications has been popularly adopted. However, most of the current commercially available planning systems do not provide the heterogeneity corrections for Brachytherapy dosimetry. In the present study, we have measured and quantified the impact of inhomogeneity caused by different tissues with a 0.015 cc ion chamber. Measurements were carried out in wax phantom which was employed to measure the heterogeneity. Iridium-192 (192 Ir source from high dose rate (HDR Brachytherapy machine was used as the radiation source. The reduction of dose due to tissue inhomogeneity was measured as the ratio of dose measured with different types of inhomogeneity (bone, spleen, liver, muscle and lung to dose measured with homogeneous medium for different distances. It was observed that different tissues attenuate differently, with bone tissue showing maximum attenuation value and lung tissue resulting minimum value and rest of the tissues giving values lying in between those of bone and lung. It was also found that inhomogeneity at short distance is considerably more than that at larger distances.

  3. Clinical result of high-dose rate intraluminal brachytherapy for esophageal carcinoma with a remote afterloading system

    International Nuclear Information System (INIS)

    Fukuda, Haruyuki; Nakajima, Toshifumi; Tada, Takuhito; Tanaka, Masahiro; Tsumura, Masashi; Onoyama, Yasuto

    1992-01-01

    During the period from 1977 through 1987, 105 patients with esophageal carcinoma were radically treated by radiotherapy. Forty-six patients receiving therapy before August 1982 were all treated by external beam therapy alone (Group 1). Since September 1982, 26 patients were treated by external beam therapy alone (Group 2) and 33 patients were treated by high-dose-rate intraluminal brachytherapy with a remote afterloading system combined with external beam therapy (Group 3). Dose of external beam therapy for Group 1, Group 2 and Group 3 patients were 66.7 Gy, 68.7 Gy and 55.9 Gy on the average. The intraluminal brachytherapy was performed with a total dose of 12 Gy consisting of 3 Gy twice a week. Ten of 72 patients (14%) treated by external beam therapy alone achieved complete response, whereas 14 of 33 patients (42%) treated by high-dose-rate intraluminal brachytherapy combined with external beam therapy had complete response. One-, and 3-year survival rates were 36% and 10% in the Group 1, 32% and 12% in the Group 2 and 56% and 36% in the Group 3. For Group 3, good survival rate was obtained in tumorous type and serrated type. Patients with tumor of less than 5 cm in Group 3 had good survival. The data suggest that the high-dose-rate intraluminal bracytherapy prescribed as a boost therapy following external beam therapy is an effective therapy modality for esophageal carcinoma which is of non-circumferential tumor or less than 5 cm. (author)

  4. Low-dose-rate interstitial brachytherapy preserves good quality of life in buccal mucosa cancer patients

    International Nuclear Information System (INIS)

    Tayier, A.; Hayashi, Keiji; Yoshimura, Ryoichi

    2011-01-01

    The purpose of this study was to determine the results and long-term changes in radiation toxicity of stage I-II buccal mucosa cancer patients treated by low-dose-rate (LDR) brachytherapy with 198 Au grains. A total of 133 stage I-II buccal mucosa carcinomas patients received 198 Au grain implantation brachytherapy between January 1982 and July 2005: 75 of them were treated by 198 Au grain implantation alone and 58 were treated by 198 Au implantation in combination with external irradiation. The average 198 Au-grain dose was 70 Gy in 7 days. Gross tumor areas ranged from 2.4 cm 2 to 9 cm 2 , and the clinical target areas ranged from 6 cm 2 to 15 cm 2 . The follow-up periods ranged from 3 months to 20 years (mean: 5 years 11 months and median: 5 years 1 months). Failure at the site of the primary lesion occurred in 17 patients. Post-treatment mucosal ulceration developed in 15 patients, and all were cured within 25 months by conservative treatment. Osteoradionecrosis was diagnosed in 8 patients, but only one patient required surgical treatment. No severe complications or aggravation of complications developed more than 10 years after treatment. The results of low-dose-rate (LDR)-brachytherapy (BT) alone and LDR-BT in combination with external irradiation at a total dose of 25 Gy were acceptable from the standpoint of cure rate and quality of life (QOL). (author)

  5. Comparison of high dose rate (HDR) and low dose rate (LDR) brachytherapy in the treatment of stage IIIB cervix cancer with radiation therapy alone. The preliminary results

    International Nuclear Information System (INIS)

    Trippe, Nivaldo; Novaes, P.E.; Ferrigno, R.; Pellizzon, A.C.; Salvajoli, J.V.; Fogaroli, R.C.; Maia, M.A.C.; Baraldi, H.E.

    1996-01-01

    Purpose/Objective: To compare the results between HDR and LDR brachytherapy in the treatment of stage IIIB cervix cancer with radiation therapy alone through a prospective and randomized trial. Materials and Methods: From September 1992 to December 1993, 65 patients with stage IIIB cervical cancer were randomized to one of the following treatment schedule according to the brachytherapy used to complement the dose of external beam radiotherapy (EBRT): 1 - High dose rate (HDR) - 36 patients - 4 weekly insertions of 6,0 Gy at point A 2 - Low dose rate (LDR) - 29 patients - 2 insertions two weeks apart of 17,5 Gy at point A The External Beam radiotherapy was performed through a Linac 4MV, in box arrangement for whole pelvis and in AP-PA fields for parametrial complementation of dose. The dose at the whole pelvis was 45 Gy in 25 fractions of 1,8 Gy and the parametrial dose was 16 Gy. The brachytherapy was realized with Fletcher colpostats and intrauterine tandem, in both arms. The HDR brachytherapy was realized through a Micro-Selectron device, working with Iridium-192 with initial activity of 10 Ci and started ten days after the beginning of EBRT. The total treatment time was shortened in two weeks for this group. The LDR brachytherapy started only after the end of EBRT. Results: With the minimum follow up of 24 months and medium of 31 months, the disease free survival was 50% among the 36 patients in HDR group and 47,8% among the 29 patients in LDR group. Local failures occurred in 50% and 52,8% respectively. Grade I and II complications were restricted to rectites and cistites and the incidence of them was 8,3% for HDR group and 13% for LDR group. Until the time of evaluation there were no grade III complications in any group. Conclusions: Although the number of patients is small and the time of follow up still short, these preliminary results suggest that the HDR brachytherapy has an equivalent efficiency in local control as the LDR in the treatment of stage IIIB

  6. MRI-Guided High–Dose-Rate Intracavitary Brachytherapy for Treatment of Cervical Cancer: The University of Pittsburgh Experience

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Beant S.; Kim, Hayeon; Houser, Christopher J. [Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Kelley, Joseph L.; Sukumvanich, Paniti; Edwards, Robert P.; Comerci, John T.; Olawaiye, Alexander B.; Huang, Marilyn; Courtney-Brooks, Madeleine [Department of Gynecologic Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States); Beriwal, Sushil, E-mail: beriwals@upmc.edu [Department of Radiation Oncology, Magee-Womens Hospital of University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (United States)

    2015-03-01

    Purpose: Image-based brachytherapy is increasingly used for gynecologic malignancies. We report early outcomes of magnetic resonance imaging (MRI)-guided brachytherapy. Methods and Materials: Consecutive patient cases with FIGO stage IB1 to IVA cervical cancer treated at a single institution were retrospectively reviewed. All patients received concurrent cisplatin with external beam radiation therapy along with interdigitated high–dose-rate intracavitary brachytherapy. Computed tomography or MRI was completed after each application, the latter acquired for at least 1 fraction. High-risk clinical target volume (HRCTV) and organs at risk were identified by Groupe Européen de Curiethérapie and European SocieTy for Radiotherapy and Oncology guidelines. Doses were converted to equivalent 2-Gy doses (EQD{sub 2}) with planned HRCTV doses of 75 to 85 Gy. Results: From 2007 to 2013, 128 patients, median 52 years of age, were treated. Predominant characteristics included stage IIB disease (58.6%) with a median tumor size of 5 cm, squamous histology (82.8%), and no radiographic nodal involvement (53.1%). Most patients (67.2%) received intensity modulated radiation therapy (IMRT) at a median dose of 45 Gy, followed by a median brachytherapy dose of 27.5 Gy (range, 25-30 Gy) in 5 fractions. At a median follow up of 24.4 months (range, 2.1-77.2 months), estimated 2-year local control, disease-free survival, and cancer-specific survival rates were 91.6%, 81.8%, and 87.6%, respectively. Predictors of local failure included adenocarcinoma histology (P<.01) and clinical response at 3 months (P<.01). Among the adenocarcinoma subset, receiving HRCTV D{sub 90} EQD{sub 2} ≥84 Gy was associated with improved local control (2-year local control rate 100% vs 54.5%, P=.03). Grade 3 or greater gastrointestinal or genitourinary late toxicity occurred at a 2-year actuarial rate of 0.9%. Conclusions: This study constitutes one of the largest reported series of MRI

  7. Physics and quality assurance for high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Anderson, Lowell L.

    1995-01-01

    Purpose: To review the physical aspects of high dose rate (HDR) brachytherapy, including commissioning and quality assurance, source calibration and dose distribution measurements, and treatment planning methods. Following the introduction of afterloading in brachytherapy, development efforts to make it 'remote' culminated in 1964 with the near-simultaneous appearance of remote afterloaders in five major medical centers. Four of these machines were 'high dose rate', three employing 60Co and one (the GammaMed) using a single, cable-mounted 192Ir source. Stepping-motor source control was added to the GammaMed in 1974, making it the precursor of modern remote afterloaders, which are now suitable for interstitial as well as intracavitary brachytherapy by virtue of small source-diameter and indexer-accessed multiple channels. Because the 192Ir sources currently used in HDR remote afterloaders are supplied at a nominal air-kerma strength of 11.4 cGy cm2 s-1 (10 Ci), are not collimated in clinical use, and emit a significant fraction (15%) of photons at energies greater than 600 keV, shielding and facility design must be undertaken as carefully and thoroughly as for external beam installations. Licensing requirements of regulatory agencies must be met with respect both to maximum permissible dose limits and to the existence and functionality of safety devices (door interlocks, radiation monitors, etc.). Commissioning and quality assurance procedures that must be documented for HDR remote afterloading relate to (1) machine, applicator, guide-tube, and facility functionality checks, (2) source calibration, (3) emergency response readiness, (4) planning software evaluation, and (5) independent checks of clinical dose calculations. Source calibration checks must be performed locally, either by in-air measurement of air kerma strength or with a well ionization chamber calibrated (by an accredited standards laboratory) against an in-air measurement of air kerma strength for the

  8. Custom-made micro applicators for high-dose-rate brachytherapy treatment of chronic psoriasis

    Directory of Open Access Journals (Sweden)

    Ivan M. Buzurovic

    2017-06-01

    Full Text Available Purpose: In this study, we present the treatment of the psoriatic nail beds of patients refractory to standard therapies using high-dose-rate (HDR brachytherapy. The custom-made micro applicators (CMMA were designed and constructed for radiation dose delivery to small curvy targets with complicated topology. The role of the HDR brachytherapy treatment was to stimulate the T cells for an increased immune response. Material and methods: The patient diagnosed with psoriatic nail beds refractory to standard therapies received monthly subunguinal injections that caused significant pain and discomfort in both hands. The clinical target was defined as the length from the fingertip to the distal interphalangeal joint. For the accurate and reproducible setup in the multi-fractional treatment delivery, the CMMAs were designed. Five needles were embedded into the dense plastic mesh and covered with 5 mm bolus material for each micro applicator. Five CMMAs were designed, resulting in the usage of 25 catheters in total. Results: The prescription dose was planned to the depth of the anterior surface of the distal phalanx, allowing for the sparing of the surrounding tissue. The total number of the active dwell positions was 145 with step size of 5 mm. The total treatment time was 115 seconds with a 7.36 Ci activity of the 192Ir source. The treatment resulted in good pain control. The patient did not require further injections to the nail bed. After this initial treatment, additional two patients with similar symptoms received HDR brachytherapy. The treatment outcome was favorable in all cases. Conclusions : The first HDR brachytherapy treatment of psoriasis of the nail bed is presented. The initial experience revealed that brachytherapy treatment was well-tolerated and resulted in adequate control of the disease. A larger cohort of patients will be required for additional conclusions related to the long-term clinical benefits.

  9. Evaluation of functioning of high dose rate brachytherapy at the Instituto Nacional do Cancer

    International Nuclear Information System (INIS)

    Guedes, Laura M.A.; Barreto, Rodrigo V.; Silva, Penha M.; Macedo, Afranio A.; Borges, Solange C.; Martinez, Valeria P.O.

    2001-01-01

    Quality control tests are very useful tools to assure the quality of patient's treatment. A daily control of the high dose rate micro selectron was performed based on the security parameters of the equipment and on the quickness of performance. The purpose of this report is to evaluate and to discuss the errors found during the first three years with the high dose rate brachytherapy, at the Instituto Nacional de Cancer. (author)

  10. Minimal percentage of dose received by 90% of the urethra (%UD90) is the most significant predictor of PSA bounce in patients who underwent low-dose-rate brachytherapy (LDR-brachytherapy) for prostate cancer.

    Science.gov (United States)

    Tanaka, Nobumichi; Asakawa, Isao; Fujimoto, Kiyohide; Anai, Satoshi; Hirayama, Akihide; Hasegawa, Masatoshi; Konishi, Noboru; Hirao, Yoshihiko

    2012-09-14

    To clarify the significant clinicopathological and postdosimetric parameters to predict PSA bounce in patients who underwent low-dose-rate brachytherapy (LDR-brachytherapy) for prostate cancer. We studied 200 consecutive patients who received LDR-brachytherapy between July 2004 and November 2008. Of them, 137 patients did not receive neoadjuvant or adjuvant androgen deprivation therapy. One hundred and forty-two patients were treated with LDR-brachytherapy alone, and 58 were treated with LDR-brachytherapy in combination with external beam radiation therapy. The cut-off value of PSA bounce was 0.1 ng/mL. The incidence, time, height, and duration of PSA bounce were investigated. Clinicopathological and postdosimetric parameters were evaluated to elucidate independent factors to predict PSA bounce in hormone-naïve patients who underwent LDR-brachytherapy alone. Fifty patients (25%) showed PSA bounce and 10 patients (5%) showed PSA failure. The median time, height, and duration of PSA bounce were 17 months, 0.29 ng/mL, and 7.0 months, respectively. In 103 hormone-naïve patients treated with LDR-brachytherapy alone, and univariate Cox proportional regression hazard model indicated that age and minimal percentage of the dose received by 30% and 90% of the urethra were independent predictors of PSA bounce. With a multivariate Cox proportional regression hazard model, minimal percentage of the dose received by 90% of the urethra was the most significant parameter of PSA bounce. Minimal percentage of the dose received by 90% of the urethra was the most significant predictor of PSA bounce in hormone-naïve patients treated with LDR-brachytherapy alone.

  11. Adherence to Vaginal Dilation Following High Dose Rate Brachytherapy for Endometrial Cancer

    International Nuclear Information System (INIS)

    Friedman, Lois C.; Abdallah, Rita; Schluchter, Mark; Panneerselvam, Ashok; Kunos, Charles A.

    2011-01-01

    Purpose: We report demographic, clinical, and psychosocial factors associated with adherence to vaginal dilation and describe the sexual and marital or nonmarital dyadic functioning of women following high dose rate (HDR) brachytherapy for endometrial cancer. Methods and Materials: We retrospectively evaluated women aged 18 years or older in whom early-stage endometrial (IAgr3-IIB) cancers were treated by HDR intravaginal brachytherapy within the past 3.5 years. Women with or without a sexual partner were eligible. Patients completed questionnaires by mail or by telephone assessing demographic and clinical variables, adherence to vaginal dilation, dyadic satisfaction, sexual functioning, and health beliefs. Results: Seventy-eight of 89 (88%) eligible women with early-stage endometrial cancer treated with HDR brachytherapy completed questionnaires. Only 33% of patients were adherers, based on reporting having used a dilator more than two times per week in the first month following radiation. Nonadherers who reported a perceived change in vaginal dimension following radiation reported that their vaginas were subjectively smaller after brachytherapy (p = 0.013). Adherers reported more worry about their sex lives or lack thereof than nonadherers (p = 0.047). Patients reported considerable sexual dysfunction following completion of HDR brachytherapy. Conclusions: Adherence to recommendations for vaginal dilator use following HDR brachytherapy for endometrial cancer is poor. Interventions designed to educate women about dilator use benefit may increase adherence. Although sexual functioning was compromised, it is likely that this existed before having cancer for many women in our study.

  12. Late complications after high-dose-rate interstitial brachytherapy for tongue cancer

    International Nuclear Information System (INIS)

    Shimizutani, Kimishige; Inoue, Takehiro; Inoue, Toshihiko; Yoshioka, Yasuo; Teshima, Teruki; Kakimoto, Naoya; Murakami, Shumei; Furukawa, Souhei; Fuchihata, Hajime

    2005-01-01

    The objectives of this study was to analyze the treatment results and late complications of high-dose-rate (HDR) interstitial brachytherapy (ISBT) for early (T1N0, T2N0) mobile tongue cancer using the microSelectron-HDR. From January 1993 through April 2001, a total of 72 patients with early squamous cell carcinomas of the mobile tongue were treated with microSelectron-HDR interstitial brachytherapy at the Department of Radiology, Osaka University Hospital. Of the patients, 18% were treated with a combination of prior external radiation and HDR-ISBT, and 82% were treated with HDR-ISBT alone. For HDR-ISBT alone, all cases were treated with a total dose of 54 Gy/9 fractions every 5 days or 60 Gy/10 fractions every 8 days. In combined therapy with an external dose of 30 to 40 Gy, HDR-ISBT was given at a total dose of 42-50 Gy. The Brinkman and alcohol indexes were used to analyze the incidence of late complications after HDR-ISBT. The 2- and 5-year local control rates were 85% and 82%, respectively. Fifteen of 72 patients (21%) treated with HDR-ISBT had late complications. Ten of 15 patients (67%) with late complications had a Brinkman index exceeding 600. HDR-ISBT is useful and easily applied under local anesthesia to early or superficial lesions of the mobile tongue. However, we found an increase in late complications, such as soft-tissue ulcers and bone exposure, after irradiation of tongue cancer with 60 Gy HDR-ISBT in patients with a Brinkman index greater than 600. (author)

  13. High dose rate afterloading intraluminal brachytherapy for advanced inoperable rectal carcinoma

    International Nuclear Information System (INIS)

    Hoskin, Peter J.; Canha, Sandra M. de; Bownes, Peter; Bryant, Linda; Jones, Rob Glynne

    2004-01-01

    Background and purpose: High dose rate intraluminal brachytherapy for tumours of the rectal and anal canal which were inoperable either because of the age and frailty of the patient or because of advanced disease has been evaluated. Patients and methods: In a retrospective review of 50 consecutive patients the two main indications for brachytherapy were as part of a radical radiation programme in those unfit for major surgery (26 patients) or as palliation for advanced or metastatic disease (22 patients). Radical treatment was either sole treatment delivering 6 Gy fraction 2 to 3 times weekly up to 36 Gy or as a boost of 12 Gy after 45 Gy in 25 fractions external beam chemoradiation. Palliative treatments were given predominantly as a single dose of 10 Gy. Results: This was predominantly a group of frail elderly patients with a median age of 82 years (range 35-91). Local tumour response was seen in 21/25 assessable patients with 14 complete responses. Median survival for the entire population was 6 months (range 1-54 months); in patients treated with 'radical' intent this was 25 months (range 1.5-54) and in the palliative group 7.2 months (range 1-37). The most common presenting symptom was bleeding per rectum for which a 64% response rate was obtained with 57% complete responses. Mucous discharge responded in 64% with 28% complete responses. The median duration of response was 7 months. Conclusion: Intraluminal HDR brachytherapy is an effective local treatment for patients otherwise unfit for radical surgery both as a component of radical treatment, or as a simple single palliative procedure

  14. Retrospective analysis of dose delivery in intra-operative high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Oh, M.; Avadhani, J.S.; Malhotra, H.K.; Cunningham, B.; Tripp, P.; Jaggernauth, W.; Podgorsak, M.B.

    2007-01-01

    Background. This study was performed to quantify the inaccuracy in clinical dose delivery due to the incomplete scatter conditions inherent in intra-operative high dose rate (IOHDR) brachytherapy. Methods. Treatment plans of 10 patients previously treated in our facility, which had irregular shapes of treated areas, were used. Treatment geometries reflecting each clinical case were simulated using a phantom assembly with no added build-up on top of the applicator. The treatment planning geometry (full scatter surrounding the applicator) was subsequently simulated for each case by adding bolus on top of the applicator. Results. For geometries representing the clinical IOHDR incomplete scatter environment, measured doses at the 5 mm and 10 mm prescription depths were lower than the corresponding prescribed doses by about 7.7% and 11.1%, respectively. Also, for the two prescription methods, an analysis of the measured dose distributions and their corresponding treatment plans showed average decreases of 1.2 mm and 2.2 mm in depth of prescription dose, respectively. Conclusions. Dosimetric calculations with the assumption of an infinite scatter environment around the applicator and target volume have shown to result in dose delivery errors that significantly decrease the prescription depth for IOHDR treatment.(author)

  15. Low-Dose-Rate Brachytherapy Versus Cryotherapy in Low- and Intermediate-Risk Prostate Cancer.

    Science.gov (United States)

    Gestaut, Matthew M; Cai, Wendi; Vyas, Shilpa; Patel, Belur J; Hasan, Salman A; MunozMaldonado, Yolanda; Deb, Niloyjyoti; Swanson, Gregory

    2017-05-01

    Cryotherapy and brachytherapy are definitive local treatment options for low- to intermediate-risk prostate cancer. There are both prospective and retrospective data for brachytherapy, but the use of cryotherapy has been limited primarily to single-institution retrospective studies. Currently, no published evidence has compared low-dose-rate brachytherapy versus cryotherapy. Institutional review board approval was obtained to conduct a retrospective chart review of consecutive patients treated at our institution from 1990 to 2012. For inclusion, patients must have received a prostate cancer diagnosis and have been considered to have low- to intermediate-risk disease according to the National Comprehensive Cancer Network criteria. All patients received brachytherapy or cryotherapy treatment. Disease specifics and failure details were collected for all patients. Failure was defined as prostate-specific antigen nadir +2 ng/mL. A total of 359 patients were analyzed. The groups comprised 50 low-risk cryotherapy (LRC), 92 intermediate-risk cryotherapy (IRC), 133 low-risk brachytherapy (LRB), and 84 intermediate-risk brachytherapy (IRB) patients. The median prostate-specific antigen follow-up periods were 85.6 months (LRC), 59.2 months (IRC), 74.9 months (LRB), and 59.8 months (IRB). The 5-year biochemical progression-free survival (bPFS) rate was 57.9% in the cryotherapy group versus 89.6% in the brachytherapy group (Pcryotherapy for low- and intermediate-risk groups (Pcryotherapy patients was -35°C (range, -96°C to -6°C). Cryotherapy used a median of 2 freeze-thaw cycles (range, 2-4 freeze-thaw cycles). Results from this study suggest that cryotherapy is inferior to brachytherapy for patients with low- to intermediate-risk prostate cancer. Patient selection criteria for consideration of cryotherapy and brachytherapy are similar in terms of anesthesia candidacy. Therefore, cryotherapy would not be recommended as a first-line local therapy for this particular

  16. Comparison of 60Cobalt and 192Iridium sources in high dose rate afterloading brachytherapy

    International Nuclear Information System (INIS)

    Richter, J.; Baier, K.; Flentje, M.

    2008-01-01

    Purpose: 60 Co sources with dimensions identical to those of 192 Ir have recently been made available in clinical brachytherapy. A longer half time reduces demands on logistics and quality assurance and perhaps costs. Material and Methods: Comparison of the physical properties of 60 Co and 192 Ir with regard to brachytherapy. Results: Required activities for the same air kerma rate are lower by a factor of 2.8 for 60 Co. Differential absorption in tissues of different densities can be neglected. Monte Carlo calculations demonstrate that integral dose due to radial dose fall off is higher for 192 Ir in comparison to 60 Co within the first 22 cm from the source (normalization at 1 cm). At larger distances this relationship is reversed. Conclusion: Clinical examples for intracavitary and interstitial applications however, show practically identical dose distributions in the treatment volume. (orig.)

  17. HDRMC, an accelerated Monte Carlo dose calculator for high dose rate brachytherapy with CT-compatible applicators

    Energy Technology Data Exchange (ETDEWEB)

    Chibani, Omar, E-mail: omar.chibani@fccc.edu; C-M Ma, Charlie [Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111 (United States)

    2014-05-15

    Purpose: To present a new accelerated Monte Carlo code for CT-based dose calculations in high dose rate (HDR) brachytherapy. The new code (HDRMC) accounts for both tissue and nontissue heterogeneities (applicator and contrast medium). Methods: HDRMC uses a fast ray-tracing technique and detailed physics algorithms to transport photons through a 3D mesh of voxels representing the patient anatomy with applicator and contrast medium included. A precalculated phase space file for the{sup 192}Ir source is used as source term. HDRM is calibrated to calculated absolute dose for real plans. A postprocessing technique is used to include the exact density and composition of nontissue heterogeneities in the 3D phantom. Dwell positions and angular orientations of the source are reconstructed using data from the treatment planning system (TPS). Structure contours are also imported from the TPS to recalculate dose-volume histograms. Results: HDRMC was first benchmarked against the MCNP5 code for a single source in homogenous water and for a loaded gynecologic applicator in water. The accuracy of the voxel-based applicator model used in HDRMC was also verified by comparing 3D dose distributions and dose-volume parameters obtained using 1-mm{sup 3} versus 2-mm{sup 3} phantom resolutions. HDRMC can calculate the 3D dose distribution for a typical HDR cervix case with 2-mm resolution in 5 min on a single CPU. Examples of heterogeneity effects for two clinical cases (cervix and esophagus) were demonstrated using HDRMC. The neglect of tissue heterogeneity for the esophageal case leads to the overestimate of CTV D90, CTV D100, and spinal cord maximum dose by 3.2%, 3.9%, and 3.6%, respectively. Conclusions: A fast Monte Carlo code for CT-based dose calculations which does not require a prebuilt applicator model is developed for those HDR brachytherapy treatments that use CT-compatible applicators. Tissue and nontissue heterogeneities should be taken into account in modern HDR

  18. The Meaning and Experience of Patients Undergoing Rectal High-Dose-Rate Brachytherapy.

    Science.gov (United States)

    Perez, Samara; Néron, Sylvain; Benc, Renata; Rosberger, Zeev; Vuong, Té

    2016-01-01

    High-dose-rate (HDR) brachytherapy is a precise form of radiation therapy that targets cancerous tumors by directly applying the radiation source at the site or directly next to the tumor. Patients often experience but underreport pain and anxiety related to cancer treatments. At present, there is no research available concerning the pervasiveness and intensity of patients' pain and anxiety during rectal brachytherapy. The aim of this study was to examine patients' thoughts, emotions, coping strategies, physical sensations, and needs during rectal HDR brachytherapy treatment. Twenty-five patients with rectal cancer were interviewed using a semi-structured qualitative interview following the completion of their brachytherapy treatment delivered at a Montreal-based hospital in Quebec, Canada. The experiences of pain and discomfort varied greatly between patients and were linked to the meaning patients attributed to the treatment itself, sense of time, the body's lithotomic position, insertion of the treatment applicator, and the patients' sense of agency and empowerment during the procedure. Patients drew upon a variety of internal and external resources to help them cope with discomfort. Staff need to know about the variation in the physical and emotional experiences of patients undergoing this treatment. Clinical teams can tailor their procedural behavior (eg, using certain language, psychosocial interventions) according to patients' needs to increase patients' comfort and ultimately improve their experience of HDR rectal brachytherapy.

  19. Intestinal morphological effect of brachytherapy of low rate of dose, administrated in therapeutic form and its clinical manifestations in uterine cervix tumors

    International Nuclear Information System (INIS)

    Mendoza, Carmen; Contreras, Manuel

    2005-01-01

    Brachytherapy is effective to eradicate cancer in the cervix, in order to obtain the control of disease we use high dose with vesical and rectum toxicity. The objective is to investigate if brachytherapy by itself is the cause of intestinal damage, to know in addition if the intensity of the clinic manifestations is in direct relation to the given radiation dose and this gets worse when it is received in several applications. Hypothesis: The intensity of the radiation with brachytherapy of low rate of dose is proportional to the degree of clinical manifestations and morphologic damage of the intestine. A prospective analysis was made inpatients with cancer of cervix from september 2000 to june 2004. Each patient who enters to the department of brachytherapy of the hospital must be done laboratory examination that includes plaque and coagulation test before being accepted. We use the clinical card and a table in order to register data concerning teletherapy, implants of brachytherapy of low rate of dose, symptoms of intestinal toxicity and details of colonoscopia. Subsequent to the hospitable discharge the patient is sent to gastroenterology for clinical evaluation and to realize colonoscopia. From september 2000 to june 2004, 540 patients entered, 80 patients (15%) displayed intestinal manifestations, all received teletherapy and brachytherapy, nobody else received brachytherapy in exclusive form and only one patient (0.1%) received the total of the dose in 2 applications. The equipment of teletherapy Primus with energy of 6 and 18 Mv and implants of brachytherapy Manchester were used (70/55 patients). 79 (98%) patients received dose between 85-75 Gy in one single application, 58 (72%) received the total of the dose to the tumor, 21 (26%) in vaginal mucosa. Discussion: Brachytherapy is the cause of the damages in the intestinal mucosa. (The author)

  20. Sci-Thur PM – Brachytherapy 04: Commissioning and Implementation of a Cobalt-60 High Dose Rate Brachytherapy Source

    Energy Technology Data Exchange (ETDEWEB)

    Dysart, Jonathan [Horizon Health Network (Canada)

    2016-08-15

    An Eckert & Ziegler Bebig Co0.A86 cobalt 60 high dose rate (HDR) brachytherapy source was commissioned for clinical use. Long-lived Co-60 HDR sources offer potential logistical and economic advantages over Ir-192 sources, and should be considered for low to medium workload brachytherapy departments where modest increases in treatment times are not a factor. In optimized plans, the Co-60 source provides a similar dose distribution to Ir-192 despite the difference in radiation energy. By switching to Co-60, source exchange frequency can be reduced by a factor of 20, resulting in overall financial savings of more than 50% compared to Ir-192 sources. In addition, a reduction in Physicist QA workload of roughly 200 hours over the 5 year life of the Co-60 source is also expected. These benefits should be considered against the modest increases in average treatment time compared to those of Ir-192 sources, as well as the centre-specific needs for operating room shielding modification.

  1. The optimal fraction size in high-dose-rate brachytherapy: dependency on tissue repair kinetics and low-dose rate

    International Nuclear Information System (INIS)

    Sminia, Peter; Schneider, Christoph J.; Fowler, Jack F.

    2002-01-01

    Background and Purpose: Indications of the existence of long repair half-times on the order of 2-4 h for late-responding human normal tissues have been obtained from continuous hyperfractionated accelerated radiotherapy (CHART). Recently, these data were used to explain, on the basis of the biologically effective dose (BED), the potential superiority of fractionated high-dose rate (HDR) with large fraction sizes of 5-7 Gy over continuous low-dose rate (LDR) irradiation at 0.5 Gy/h in cervical carcinoma. We investigated the optimal fraction size in HDR brachytherapy and its dependency on treatment choices (overall treatment time, number of HDR fractions, and time interval between fractions) and treatment conditions (reference low-dose rate, tissue repair characteristics). Methods and Materials: Radiobiologic model calculations were performed using the linear-quadratic model for incomplete mono-exponential repair. An irradiation dose of 20 Gy was assumed to be applied either with HDR in 2-12 fractions or continuously with LDR for a range of dose rates. HDR and LDR treatment regimens were compared on the basis of the BED and BED ratio of normal tissue and tumor, assuming repair half-times between 1 h and 4 h. Results: With the assumption that the repair half-time of normal tissue was three times longer than that of the tumor, hypofractionation in HDR relative to LDR could result in relative normal tissue sparing if the optimum fraction size is selected. By dose reduction while keeping the tumor BED constant, absolute normal tissue sparing might therefore be achieved. This optimum HDR fraction size was found to be largely dependent on the LDR dose rate. On the basis of the BED NT/TUM ratio of HDR over LDR, 3 x 6.7 Gy would be the optimal HDR fractionation scheme for replacement of an LDR scheme of 20 Gy in 10-30 h (dose rate 2-0.67 Gy/h), while at a lower dose rate of 0.5 Gy/h, four fractions of 5 Gy would be preferential, still assuming large differences between tumor

  2. Reirradiation for recurrent head and neck cancer with salvage interstitial pulsed-dose-rate brachytherapy. Long-term results

    Energy Technology Data Exchange (ETDEWEB)

    Strnad, Vratislav; Lotter, Michael; Kreppner, Stephan; Fietkau, Rainer [University Hospital Erlangen, Dept. of Radiation Oncology, Erlangen (Germany)

    2015-01-10

    To assess the long-term results of protocol-based interstitial pulsed-dose-rate (PDR) brachytherapy as reirradiation combined with simultaneous chemotherapy and interstitial hyperthermia in selected patients with recurrent head and neck tumors. A total of 104 patients with biopsy-proven recurrent head and neck cancer were treated with interstitial PDR brachytherapy. Salvage surgery had also been undergone by 53/104 (51 %) patients (R1 or R2 resection in > 80 % of patients). Salvage brachytherapy alone was administered in 81 patients (78 %), with a median total dose of 56.7 Gy. Salvage brachytherapy in combination with external beam radiotherapy (EBRT) was performed in 23/104 patients (32 %), using a median total dose of D{sub REF} = 24 Gy. Simultaneously to PDR brachytherapy, concomitant chemotherapy was administered in 58/104 (55.8 %) patients. A single session of interstitial hyperthermia was also used to treat 33/104 (31.7 %) patients. The analysis was performed after a median follow-up of 60 months. Calculated according to Kaplan-Meier, local tumor control rates after 2, 5, and 10 years were 92.5, 82.4, and 58.9 %, respectively. Comparing results of salvage PDR brachytherapy with or without simultaneous chemotherapy, the 10-year local control rates were 76 vs. 39 % (p= 0014), respectively. No other patient- or treatment-related parameters had a significant influence on treatment results. Soft tissue necrosis or bone necrosis developed in 18/104 (17.3 %) and 11/104 (9.6 %) patients, respectively, but only 3 % of patients required surgical treatment. PDR interstitial brachytherapy with simultaneous chemotherapy is a very effective and, in experienced hands, also a safe treatment modality in selected patients with head and neck cancer in previously irradiated areas. (orig.) [German] Es erfolgte die Analyse der Langzeitergebnisse einer protokollbasierten interstitiellen Brachytherapie (Re-Bestrahlung) mit simultaner Chemotherapie und interstitieller Hyperthermie

  3. Advantages of high-dose rate (HDR) brachytherapy in treatment of prostate cancer

    Science.gov (United States)

    Molokov, A. A.; Vanina, E. A.; Tseluyko, S. S.

    2017-09-01

    One of the modern methods of preserving organs radiation treatment is brachytherapy. This article analyzes the results of prostate brachytherapy. These studies of the advantages of high dose brachytherapy lead to the conclusion that this method of radiation treatment for prostate cancer has a favorable advantage in comparison with remote sensing methods, and is competitive, preserving organs in comparison to surgical methods of treatment. The use of the method of polyfocal transperineal biopsy during the brachytherapy session provides information on the volumetric spread of prostate cancer and adjust the dosimetry plan taking into account the obtained data.

  4. High-dose-rate brachytherapy using molds for oral cavity cancer. The technique and its limitations

    International Nuclear Information System (INIS)

    Nishimura, Yasumasa; Yokoe, Yoshihiko; Nagata, Yasushi; Okajima, Kaoru; Nishida, Mitsuo; Hiraoka, Masahiro

    1998-01-01

    With the availability of a high-dose-rate (HDR) remote afterloading device, a Phase I/II protocol was initiated at our institution to assess the toxicity and efficacy of HDR intracavitary brachytherapy, using molds, in the treatment of squamous cell carcinomas of the oral cavity. Eight patients with squamous cell carcinoma of the oral cavity were treated by the technique. The primary sites of the tumors were the buccal mucosa, oral floor, and gingiva. Two of the buccal mucosal cancers were located in the retromolar trigon. For each patient, a customized mold was fabricated, in which two to four afterloading catheters were placed for an 192 Ir HDR source. Four to seven fractions of 3-4 Gy, 5 mm below the mold surface, were given following external radiation therapy of 40-60 Gy/ 2 Gy. The total dose of HDR brachytherapy ranged from 16 to 28Gy. Although a good initial complete response rate of 7/8 (88%) was achieved, there was local recurrence in four of these seven patients. Both of the retromolar trigon tumors showed marginal recurrence. No serious (e.g., ulcer or bone exposure) late radiation damage has been observed thus far in the follow up period of 15-57 months. High-dose-rate brachytherapy using the mold technique seems a safe and useful method for selected early and superficial oral cavity cancer. However, it is not indicated for thick tumors and/or tumors located in the retromolar trigon. (author)

  5. Economic assessment of pulsed dose-rate (P.D.R.) brachytherapy with optimized dose distribution for cervix carcinoma

    International Nuclear Information System (INIS)

    Remonnay, R.; Morelle, M.; Pommier, P.; Carrere, M.O.; Remonnay, R.; Morelle, M.; Pommier, P.; Pommier, P.; Haie-Meder, C.; Quetin, P.; Kerr, C.; Delannes, M.; Castelain, B.; Peignaux, K.; Kirova, Y.; Romestaing, P.; Williaume, D.; Krzisch, C.; Thomas, L.; Lang, P.; Baron, M.H.; Cussac, A.; Lesaunier, F.; Maillard, S.; Barillot, I.; Charra-Brunaud, C.; Peiffert, D.

    2010-01-01

    Purpose: Our study aims at evaluating the cost of pulsed dose-rate (P.D.R.) brachytherapy with optimized dose distribution versus traditional treatments (iridium wires, cesium, non-optimized P.D.R.). Issues surrounding reimbursement were also explored. Materials and methods: This prospective, multi-centre, non-randomized study conducted in the framework of a project entitled 'Support Program for Costly Diagnostic and Therapeutic Innovations' involved 21 hospitals. Patients with cervix carcinoma received either classical brachytherapy or the innovation. The direct medical costs of staff and equipment, as well as the costs of radioactive sources, consumables and building renovation were evaluated from a hospital point of view using a micro costing approach. Subsequent costs per brachytherapy were compared between the four strategies. Results: The economic study included 463 patients over two years. The main resources categories associated with P.D.R. brachytherapy (whether optimized or not) were radioactive sources (1053 Euros) and source projectors (735 Euros). Optimized P.D.R. induced higher cost of imagery and dosimetry (respectively 130 Euros and 367 Euros) than non-optimized P.D.R. (47 Euros and 75 Euros). Extra costs of innovation over the less costly strategy (iridium wires) reached more than 2100 Euros per treatment, but could be reduced by half in the hypothesis of 40 patients treated per year (instead of 24 in the study). Conclusion: Aside from staff, imaging and dosimetry, the current hospital reimbursements largely underestimated the cost of innovation related to equipment and sources. (authors)

  6. Spectroscopic characterization of low dose rate brachytherapy sources

    Science.gov (United States)

    Beach, Stephen M.

    The low dose rate (LDR) brachytherapy seeds employed in permanent radioactive-source implant treatments usually use one of two radionuclides, 125I or 103Pd. The theoretically expected source spectroscopic output from these sources can be obtained via Monte Carlo calculation based upon seed dimensions and materials as well as the bare-source photon emissions for that specific radionuclide. However the discrepancies resulting from inconsistent manufacturing of sources in comparison to each other within model groups and simplified Monte Carlo calculational geometries ultimately result in undesirably large uncertainties in the Monte Carlo calculated values. This dissertation describes experimentally attained spectroscopic outputs of the clinically used brachytherapy sources in air and in liquid water. Such knowledge can then be applied to characterize these sources by a more fundamental and metro logically-pure classification, that of energy-based dosimetry. The spectroscopic results contained within this dissertation can be utilized in the verification and benchmarking of Monte Carlo calculational models of these brachytherapy sources. This body of work was undertaken to establish a usable spectroscopy system and analysis methods for the meaningful study of LDR brachytherapy seeds. The development of a correction algorithm and the analysis of the resultant spectroscopic measurements are presented. The characterization of the spectrometer and the subsequent deconvolution of the measured spectrum to obtain the true spectrum free of any perturbations caused by the spectrometer itself is an important contribution of this work. The approach of spectroscopic deconvolution that was applied in this work is derived in detail and it is applied to the physical measurements. In addition, the spectroscopically based analogs to the LDR dosimetry parameters that are currently employed are detailed, as well as the development of the theory and measurement methods to arrive at these

  7. Early quality of life outcomes in patients with prostate cancer managed by high-dose-rate brachytherapy as monotherapy

    International Nuclear Information System (INIS)

    Komiya, Akira; Fujiuchi, Yasuyoshi; Ito, Takatoshi

    2013-01-01

    The purpose of this study was to evaluate the early quality of life outcomes in prostate cancer patients managed by high-dose-rate brachytherapy as monotherapy. A total of 51 patients with cT1c-T3aN0M0 prostate cancer treated between July 2007 and January 2010 were included in this study. The average age was 69?years, and the average initial serum prostate-specific antigen was 10.98?ng/mL. A total of 25, 18 and eight patients were considered to be low, intermediate and high risk, respectively. All patients received one implant of Ir-192 and seven fractions of 6.5?Gy within 3.5?days for a total prescribed dose of 45.5?Gy. For high-risk prostate cancer, neoadjuvant androgen deprivation therapy was carried out for at least 6?months, and continued after high-dose-rate brachytherapy. Quality of life outcomes were measured by using the International Prostate Symptom Score, the Functional Assessment of Cancer Therapy-Prostate and the International Index of Erectile Function Questionnaire. The oncological outcome was assessed by serum prostate-specific antigen and diagnostic imaging. Adverse events were also recorded. The Functional Assessment of Cancer Therapy-Prostate scores decreased for a few months after high-dose-rate brachytherapy, and recovered to pretreatment condition thereafter. The International Prostate Symptom Score significantly increased 2?weeks after treatment for each of its items and their sum, and it returned to baseline after 12?weeks. Sexual function decreased at 2 and 4?weeks, and recovered after 12?weeks. Severe complications were rare. Within a median follow up of 17.2?months, two patients showed a prostate-specific antigen recurrence. High-dose-rate brachytherapy for prostate cancer is a feasible treatment modality with acceptable toxicity and only a limited impact on the quality of life. (author)

  8. Radiation proctitis after the high dose rate brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Kitano, Masashi; Katsumata, Tomoe; Satoh, Takefumi

    2006-01-01

    We reviewed the medical records of 12 patients treated for rectal bleeding after high-dose rate brachytherapy for prostate cancer. All patients developed grade 2 proctitis according to the Common Terminology Criteria for Adverse Events (CTCAC) and no patients needed blood transfusion. The patients were treated with argon plasma coagulation (APC) and/or steroid suppositories. The bleeding stopped or improved in 11 patients. Although re-bleeding was noticed in 7 patients the same treatment was effective in 5 patients. (author)

  9. Verification of the plan dosimetry for high dose rate brachytherapy using metal-oxide-semiconductor field effect transistor detectors

    International Nuclear Information System (INIS)

    Qi Zhenyu; Deng Xiaowu; Huang Shaomin; Lu Jie; Lerch, Michael; Cutajar, Dean; Rosenfeld, Anatoly

    2007-01-01

    The feasibility of a recently designed metal-oxide-semiconductor field effect transistor (MOSFET) dosimetry system for dose verification of high dose rate (HDR) brachytherapy treatment planning was investigated. MOSFET detectors were calibrated with a 0.6 cm 3 NE-2571 Farmer-type ionization chamber in water. Key characteristics of the MOSFET detectors, such as the energy dependence, that will affect phantom measurements with HDR 192 Ir sources were measured. The MOSFET detector was then applied to verify the dosimetric accuracy of HDR brachytherapy treatments in a custom-made water phantom. Three MOSFET detectors were calibrated independently, with the calibration factors ranging from 0.187 to 0.215 cGy/mV. A distance dependent energy response was observed, significant within 2 cm from the source. The new MOSFET detector has a good reproducibility ( 2 =1). It was observed that the MOSFET detectors had a linear response to dose until the threshold voltage reached approximately 24 V for 192 Ir source measurements. Further comparison of phantom measurements using MOSFET detectors with dose calculations by a commercial treatment planning system for computed tomography-based brachytherapy treatment plans showed that the mean relative deviation was 2.2±0.2% for dose points 1 cm away from the source and 2.0±0.1% for dose points located 2 cm away. The percentage deviations between the measured doses and the planned doses were below 5% for all the measurements. The MOSFET detector, with its advantages of small physical size and ease of use, is a reliable tool for quality assurance of HDR brachytherapy. The phantom verification method described here is universal and can be applied to other HDR brachytherapy treatments

  10. Monte Carlo dosimetric characterization of the Flexisource Co-60 high-dose-rate brachytherapy source using PENELOPE.

    Science.gov (United States)

    Almansa, Julio F; Guerrero, Rafael; Torres, Javier; Lallena, Antonio M

    60 Co sources have been commercialized as an alternative to 192 Ir sources for high-dose-rate (HDR) brachytherapy. One of them is the Flexisource Co-60 HDR source manufactured by Elekta. The only available dosimetric characterization of this source is that of Vijande et al. [J Contemp Brachytherapy 2012; 4:34-44], whose results were not included in the AAPM/ESTRO consensus document. In that work, the dosimetric quantities were calculated as averages of the results obtained with the Geant4 and PENELOPE Monte Carlo (MC) codes, though for other sources, significant differences have been quoted between the values obtained with these two codes. The aim of this work is to perform the dosimetric characterization of the Flexisource Co-60 HDR source using PENELOPE. The MC simulation code PENELOPE (v. 2014) has been used. Following the recommendations of the AAPM/ESTRO report, the radial dose function, the anisotropy function, the air-kerma strength, the dose rate constant, and the absorbed dose rate in water have been calculated. The results we have obtained exceed those of Vijande et al. In particular, the absorbed dose rate constant is ∼0.85% larger. A similar difference is also found in the other dosimetric quantities. The effect of the electrons emitted in the decay of 60 Co, usually neglected in this kind of simulations, is significant up to the distances of 0.25 cm from the source. The systematic and significant differences we have found between PENELOPE results and the average values found by Vijande et al. point out that the dosimetric characterizations carried out with the various MC codes should be provided independently. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  11. Clinical outcome of high-dose-rate interstitial brachytherapy in patients with oral cavity cancer

    International Nuclear Information System (INIS)

    Lee, Sung Uk; Cho, Kwan Ho; Moon, Sung Ho; Choi, Sung Weon; Park, Joo Yong; Yun, Tak; Lee, Sang Hyun; Lim, Young Kyung; Jeong, Chi Young

    2014-01-01

    To evaluate the clinical outcome of high-dose-rate (HDR) interstitial brachytherapy (IBT) in patients with oral cavity cancer. Sixteen patients with oral cavity cancer treated with HDR remote-control afterloading brachytherapy using 192Ir between 2001 and 2013 were analyzed retrospectively. Brachytherapy was administered in 11 patients as the primary treatment and in five patients as salvage treatment for recurrence after the initial surgery. In 12 patients, external beam radiotherapy (50-55 Gy/25 fractions) was combined with IBT of 21 Gy/7 fractions. In addition, IBT was administered as the sole treatment in three patients with a total dose of 50 Gy/10 fractions and as postoperative adjuvant treatment in one patient with a total of 35 Gy/7 fractions. The 5-year overall survival of the entire group was 70%. The actuarial local control rate after 3 years was 84%. All five recurrent cases after initial surgery were successfully salvaged using IBT +/- external beam radiotherapy. Two patients developed local recurrence at 3 and 5 months, respectively, after IBT. The acute complications were acceptable (< or =grade 2). Three patients developed major late complications, such as radio-osteonecrosis, in which one patient was treated by conservative therapy and two required surgical intervention. HDR IBT for oral cavity cancer was effective and acceptable in diverse clinical settings, such as in the cases of primary or salvage treatment.

  12. MRI dosimetry using an echo-quotient technique for high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Ansbacher, W.

    1996-01-01

    MRI gel dosimetry is a relatively new technique that has many advantages over conventional methods, and is particularly suited to High Dose Rate (HDR) Brachytherapy. The dosimeter has high spatial resolution and a water-equivalent response over a wide range of photon energies. Because it is an integrating dosimeter, it allows for efficient mapping of the dynamically-produced distributions from an HDR source. As an example of this technique, the dose response, which is calibrated in terms of the change in spin-spin relaxation time, has been used to investigate the anisotropy of an HDR source. (author). 1 fig

  13. High dose rate versus low dose rate brachytherapy in the treatment of stage IIIB cervical cancer, and the importance of brachytherapy timing

    International Nuclear Information System (INIS)

    Petereit, Daniel G.; Sarkaria, Jann N.; Czyzewski, Ann; Buchler, Dolores A.

    1996-01-01

    Purpose/Objective: To determine the efficacy of HDR versus LDR brachytherapy for Stage IIIB cervical cancer patients. Material and Methods: Forty-four HDR patients were retrospectively compared to 51 LDR patients treated at the same institution from 1977 to 1988 (LDR) and from 1989 to 1995 (HDR). A tumor burden score (TBS) of 2-9 was calculated for both groups of patients to assess volume of disease (2-4 low tumor burden, 5-9 high tumor burden). LDR and HDR patients received 60 Gy to the whole pelvis at 1.7 Gy/Fx. The majority of LDR patients were treated after completion of external beam radiation (EBR) with one 25 Gy implant to Point A (55 cGy/h). The HDR patients were treated with 4-5 HDR fractions of 3.7 Gy to 5.8 Gy/Fx for an LDR equivalence of 20-25 Gy (median dose/Fx 4.3 Gy, median insertion number 5). Clinical endpoints were calculated actuarially with significance determined by the log rank test and the relative risk (RR). Results: The median follow-up for the HDR and LDR groups was 1.8 and 5 years, respectively. Pelvic control and survival was better in the LDR group than the HDR group, 51%, 73%, 32%, 44% (p = 0.004, RR = 0.4), with grade III and above RTOG complications of 19% and 15%, respectively. The median age and performance status were similar between the two groups; however, a TBS score ≥7 was present in 23% of the HDR patients and in 9% of the LDR patients. Pelvic control in the HDR group was 58% with a TBS ≤4, and 17% with a TBS >4 (p = 0.01, RR = 0.4). The median EBR dose at the first HDR insertion was 31 Gy while all the LDR patients received 60 Gy before the insertion. Pelvic control rates in Table 1 indicate a trend towards improved outcome within the HDR group and same TBS if more external beam radiation was given prior to the first HDR insertion. Pelvic control was also higher within the HDR group when Point A received a BED Gy 10≥100 versus <100: 62%, 40%, respectively (RR 0.6). Conclusion: These retrospective results of HDR versus

  14. Pulsed Dose Rate (PDR - BT) brachytherapy in treatment of breast cancer

    International Nuclear Information System (INIS)

    Skowronek, J.

    2007-01-01

    Breast conserving surgery (BCS) and radiotherapy (EBRT) of the conserved breast became widely accepted in the last decades for the treatment of early invasive breast cancer. The standard technique of RT after breast conservation is to treat the whole breast up to a total dose of 45 to 50 Gy. Initially brachytherapy for breast cancer was used in addition of external radiation to boost a portion of the breast to higher doses. However, over the past 10 years, the application of brachytherapy in breast cancer has changed. In early stage breast cancer, research has shown that the area that requires radiation treatment to prevent the cancer from returning is the breast tissue that surrounds the area where the initial cancer was removed. Because this typically includes only a part of the breast, brachytherapy is now being used to treat the targeted portion of the breast and as a result allows accelerated delivery of the radiation dose so that treatment is completed in four to five days. Another indications for PDR - BT as a part of treatment in locally advanced breast cancer or as a palliative treatment are discussed in the paper, too. Preliminary results with PDR - BT boost technique are promising. However, more experience and longer follow-up are required to define whether these methods might improve local tumor control for breast cancer patients. In this article the current status, indications, technical aspects and published results of PDR brachytherapy (PDR - BT) in breast cancer treatment are reviewed. (author)

  15. A quality indicator to evaluate high-dose-rate intracavitary brachytherapy for cancer of the cervix

    International Nuclear Information System (INIS)

    Morales, Francisco Contreras; Soboll, Daniel Scheidegger

    2000-01-01

    The aim of this report is to prevent a simple quality indicator (QI) that can be promptly used to evaluate the high-dose-rate (HDR) intracavitary brachytherapy for the treatment of cancer of the cervix, and if necessary, to correct applicators' geometry before starting the treatment. We selected 51 HDR intracavitary applications of brachytherapy of patients with carcinoma of the cervix treated with 60 mm uterine tandem and small Fletcher colpostat, according to the Manchester method (dose prescription on point A). A QI was defined as the ratio between the volume of 100% isodose curve of the study insertion and the volume of the 100% isodose curve of an insertion considered to be ideal. The data obtained were distributed in three groups: the group with tandem placement slippage (67,5%), a group with colpostat placement slippage (21,9%), and a third group, considered normal (10,6%). Each group showed particular characteristics (p < 0.0001). QI can be the best auxiliary method to establish the error tolerance (%) allowed for HDR intracavitary brachytherapy. (author)

  16. Rectal dose assessment in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer; Avaliacao da dose no reto em pacientes submetidas a braquiterapia de alta taxa de dose para o tratamento do cancer do colo uterino

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Jetro Pereira de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Medicina; Rosa, Luiz Antonio Ribeiro da [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)], e-mail: lrosa@ird.gov.br; Batista, Delano Valdivino Santos; Bardella, Lucia Helena [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil). Unit of Medical Physics; Carvalho, Arnaldo Rangel [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. of Thermoluminescent Dosimetry

    2009-03-15

    Objective: The present study was aimed at developing a thermoluminescent dosimetric system capable of assessing the doses delivered to the rectum of patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. Materials and methods: LiF:Mg,Ti,Na powder was the thermoluminescent material utilized for evaluating the rectal dose. The powder was divided into small portions (34 mg) which were accommodated in a capillary tube. This tube was placed into a rectal probe that was introduced into the patient's rectum. Results: The doses delivered to the rectum of six patients submitted to high-dose-rate brachytherapy for uterine cervix cancer evaluated by means of thermoluminescent dosimeters presented a good agreement with the planned values based on two orthogonal (anteroposterior and lateral) radiographic images of the patients. Conclusion: The thermoluminescent dosimetric system developed in the present study is simple and easy to be utilized as compared to other rectal dosimetry methods. The system has shown to be effective in the evaluation of rectal doses in patients submitted to high-dose-rate brachytherapy for uterine cervix cancer. (author)

  17. Endobronchial and endoesophageal high dose rate brachytherapy for malignant airway and digestive tract obstructions

    International Nuclear Information System (INIS)

    Mehta, Minesh P.

    1996-01-01

    With an annual incidence of more than 160,000 cases and a local failure rate between 30-50%, endobronchial occlusion seen with lung cancer is a common and potentially life-threatening complication. Several methods of managing this exist and recently endobronchial brachytherapy has been used extensively as a consequence of the development of fiberoptic bronchoscopy and high dose rate remote afterloading technology. Procedurally, one or more afterloading catheters are inserted in the involved portions of the tracheobronchial tree through fiberoptic guidance. Treatment techniques range from 1-4 applications fractionated over several weeks or given over 2 days with a single insertion procedure. Almost all procedures are currently performed in the outpatient setting. The major application of this technology is in the palliation of occlusive symptomatology. Clinical improvement ranges from 50-100%, radiographic reaeration ranges from 46-88% and bronchoscopic responses ranges from 59-100%. Symptomatic relief is usually quite durable with more than 70% of the patients' remaining life-time rendered symptom-free and symptom-improved. Recently, this modality has been explored for its curative potential as a boost following external beam radiotherapy. It is clear from these series, that in selected patients, endobronchial boost produces significant reaeration and sparing of lung volume from subsequent external radiation, and a few cases may even become resectable. Demonstration of the survival advantage will, however, require larger clinical trials with adequate controls. Some reports have suggested an unacceptably high rate of fatal hemoptysis following HDR endobronchial brachytherapy. Review of the world literature suggests that fatal hemoptysis rates range from 0-50% with an average of about 8%, comparable to an average of 5% with low dose rate brachytherapy. Other recognized complications include fistulae and radiation bronchitis. Because the majority of patients with

  18. High-dose-rate brachytherapy in the treatment of uterine cervix cancer. Analysis of dose effectiveness and late complications

    International Nuclear Information System (INIS)

    Ferrigno, Robson; Novaes, Paulo Eduardo Ribeiro dos Santos; Pellizzon, Antonio Cassio Assis; Maia, Maria Aparecida Conte; Fogarolli, Ricardo Cesar; Gentil, Andre Cavalcanti; Salvajoli, Joao Victor

    2001-01-01

    Purpose: This retrospective analysis aims to report results of patients with cervix cancer treated by external beam radiotherapy (EBR) and high-dose-rate (HDR) brachytherapy. Methods and Materials: From September 1992 to December 1996, 138 patients with FIGO Stages II and III and mean age of 56 years were treated. Median EBR to the whole pelvis was 45 Gy in 25 fractions. Parametrial boost was performed in 93% of patients, with a median dose of 14.4 Gy. Brachytherapy with HDR was performed during EBR or following its completion with a dose of 24 Gy in four weekly fractions of 6 Gy to point A. Median overall treatment time was of 60 days. Patient age, tumor stage, and overall treatment time were variables analyzed for survival and local control. Cumulative biologic effective dose (BED) at rectal and bladder reference points were correlated with late complications in these organs and dose of EBR at parametrium was correlated with small bowel complications. Results: Median follow-up time was 38 months. Overall survival, disease-free survival, and local control at 5 years was 53.7%, 52.7%, and 62%, respectively. By multivariate and univariate analysis, overall treatment time up to 50 days was the only statistically significant adverse variable for overall survival (p=0.003) and actuarial local control (p=0.008). The 5-year actuarial incidence of rectal, bladder, and small bowel late complications was 16%, 11%, and 14%, respectively. Patients treated with cumulative BED at rectum points above 110 Gy 3 and at bladder point above 125 Gy 3 had a higher but not statistically significant 5-year actuarial rate of complications at these organs (18% vs. 12%, p=0.49 and 17% vs. 9%, p=0.20, respectively). Patients who received parametrial doses larger than 59 Gy had a higher 5-year actuarial rate of complications in the small bowel; however, this was not statistically significant (19% vs. 10%, p=0.260). Conclusion: This series suggests that 45 Gy to the whole pelvis combined with

  19. Physics and quality assurance for brachytherapy - Part I: High dose rates

    International Nuclear Information System (INIS)

    Anderson, Lowell L.

    1997-01-01

    Purpose: To review the physical aspects of high dose rate (HDR) brachytherapy, including commissioning and quality assurance, source calibration and dose distribution measurements, and treatment planning methods. Following the introduction of afterloading in brachytherapy, development efforts to make it 'remote' culminated in 1964 with the near-simultaneous appearance of remote afterloaders in five major medical centers. Four of these machines were 'high dose rate', three employing 60Co and one (the GammaMed) using a single, cable-mounted 192Ir source. Stepping-motor source control was added to the GammaMed in 1974, making it the precursor of modern remote afterloaders, which are now suitable for interstitial, well as intracavitary brachytherapy by virtue of small source-diameter and indexer-accessed multiple channels. Because the 192Ir sources currently used in HDR remote afterloaders are supplied at a nominal air-kerma strength of 11.4 cGy cm2 s-1 (10 Ci), are not collimated in clinical use, and emit a significant fraction (15%) of photons at energies greater than 600 keV, shielding and facility design must be undertaken as carefully and thoroughly as for external beam installations. Licensing requirements of regulatory agencies must be met with respect both to maximum permissible dose limits and to the existence and functionality of safety devices (door interlocks, radiation monitors, etc.). Commissioning and quality assurance procedures that must be documented for HDR remote afterloading relate to (1) machine, applicator, guide-tube, and facility functionality checks, (2) source calibration, (3) emergency response readiness, (4) planning software evaluation, and (5) independent checks of clinical dose calculations. Source calibration checks must be performed locally, either by in-air measurement of air kerma strength or with a well ionization chamber calibrated (by an accredited standards laboratory) against an in-air measurement of air kerma strength for the

  20. High-dose-rate brachytherapy as salvage modality for locally recurrent prostate cancer after definitive radiotherapy. A systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Chatzikonstantinou, Georgios; Zamboglou, Nikolaos; Roedel, Claus; Tselis, Nikolaos [J.W. Goethe University of Frankfurt, Department of Radiotherapy and Oncology, Frankfurt am Main (Germany); Zoga, Eleni [Sana Klinikum Offenbach, Department of Radiotherapy and Oncology, Offenbach am Main (Germany); Strouthos, Iosif [Medical Center - University of Freiburg, Department of Radiotherapy and Oncology, University of Freiburg, Freiburg (Germany); Butt, Saeed Ahmed [Sana Klinikum Offenbach, Department of Medical Physics and Engineering, Offenbach am Main (Germany)

    2017-09-15

    To review the current status of interstitial high-dose-rate brachytherapy as a salvage modality (sHDR BRT) for locally recurrent prostate cancer after definitive radiotherapy (RT). A literature search was performed in PubMed using ''high-dose-rate, brachytherapy, prostate cancer, salvage'' as search terms. In all, 51 search results published between 2000 and 2016 were identified. Data tables were generated and summary descriptions created. The main outcome parameters used were biochemical control (BC) and toxicity scores. Eleven publications reported clinical outcome and toxicity with follow-up ranging from 4-191 months. A variety of dose and fractionation schedules were described, including 19.0 Gy in 2 fractions up to 42.0 Gy in 6 fractions. The 5-year BC ranged from 18-77%. Late grade 3 genitourinary and gastrointestinal toxicity was 0-32% and 0-5.1%, respectively. sHDR BRT appears as safe and effective salvage modality for the reirradiation of locally recurrent prostate cancer after definitive RT. (orig.) [German] Zusammenfassende Darstellung relevanter Literatur zur interstitiellen High-Dose-Rate-Brachytherapie als Salvage-Modalitaet (sHDR-BRT) bei der Behandlung des lokal rezidivierten Prostatakarzinoms nach vorausgegangener definitiver Radiotherapie (RT). In der PubMed-Datenbank wurde eine Literaturrecherche mit den Suchbegriffen ''high-dose-rate, brachytherapy, prostate cancer, salvage'' durchgefuehrt. Zwischen den Jahren 2000 und 2016 wurden 51 Publikationen identifiziert. Die biochemische Kontrolle (BC) sowie das assoziierte Toxizitaetsprofil waren onkologische Hauptpunkte in der Analyse der beruecksichtigten Literatur. Von onkologischen Ergebnissen und Toxizitaeten berichteten 11 Publikationen bei einer medianen Nachbeobachtungszeit von 4-191 Monaten. Eine Variabilitaet von Dosis- und Fraktionierungsregimen wurde beschrieben mit totalen physikalischen Dosen von 19,0 Gy in 2 Fraktionen bis zu 42,0 Gy in 6 Fraktionen

  1. Bladder–Rectum Spacer Balloon in High-Dose-Rate Brachytherapy in Cervix Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Bhavana [Department of Radiotherapy and Oncology, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Patel, Firuza D., E-mail: firuzapatel@gmail.com [Department of Radiotherapy and Oncology, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Chakraborty, Santam; Sharma, Suresh C.; Kapoor, Rakesh [Department of Radiotherapy and Oncology, Regional Cancer Centre, Postgraduate Institute of Medical Education and Research, Chandigarh (India); Aprem, Abi Santhosh [Corporate R and D Division, HLL Lifecare Limited, Karamana, Trivandrum (India)

    2013-04-01

    Purpose: To compare bladder and rectum doses with the use of a bladder–rectum spacer balloon (BRSB) versus standard gauze packing in the same patient receiving 2 high-dose-rate intracavitary brachytherapy fractions. Methods and Materials: This was a randomized study to compare the reduction in bladder and rectum doses with the use of a BRSB compared with standard gauze packing in patients with carcinoma of the cervix being treated with high-dose-rate intracavitary brachytherapy. The patients were randomized between 2 arms. In arm A, vaginal packing was done with standard gauze packing in the first application, and BRSB was used in the second application. Arm B was the reverse of arm A. The International Commission for Radiation Units and Measurement (ICRU) point doses and doses to 0.1-cm{sup 3}, 1-cm{sup 3}, 2-cm{sup 3}, 5-cm{sup 3}, and 10-cm{sup 3} volumes of bladder and rectum were compared. The patients were also subjectively assessed for the ease of application and the time taken for application. Statistical analysis was done using the paired t test. Results: A total of 43 patients were enrolled; however, 3 patients had to be excluded because the BRSB could not be inserted owing to unfavorable local anatomy. Thus 40 patients (80 plans) were evaluated. The application was difficult in 3 patients with BRSB, and in 2 patients with BRSB the application time was prolonged. There was no significant difference in bladder doses to 0.1 cm{sup 3}, 1 cm{sup 3}, 2 cm{sup 3}, 5 cm{sup 3}, and 10 cm{sup 3} and ICRU bladder point. Statistically significant dose reductions to 0.1-cm{sup 3}, 1-cm{sup 3}, and 2-cm{sup 3} volumes for rectum were observed with the BRSB. No significant differences in 5-cm{sup 3} and 10-cm{sup 3} volumes and ICRU rectum point were observed. Conclusion: A statistically significant dose reduction was observed for small high-dose volumes in rectum with the BRSB. The doses to bladder were comparable for BRSB and gauze packing. Transparent balloons of

  2. Inter fraction variations in rectum and bladder volumes and dose distributions during high dose rate brachytherapy treatment of the uterine cervix investigated by repetitive CT-examinations

    International Nuclear Information System (INIS)

    Hellebust, Taran Paulsen; Dale, Einar; Skjoensberg, Ane; Olsen, Dag Rune

    2001-01-01

    Purpose: To evaluate variation of dose to organs at risk for patients receiving fractionated high dose rate gynaecological brachytherapy by using CT-based 3D treatment planning and dose-volume histograms (DVH). Materials and methods: Fourteen patients with cancer of the uterine cervix underwent three to six CT examinations (mean 4.9) during their course of high-dose-rate brachytherapy using radiographically compatible applicators. The rectal and bladder walls were delineated and DVHs were calculated. Results: Inter fraction variation of the bladder volume (CV mean =44.1%) was significantly larger than the inter fraction variation of the mean dose (CV mean =19.9%, P=0.005) and the maximum dose (CV mean =17.5%, P=0.003) of the bladder wall. The same trend was seen for rectum, although the figures were not significantly different. Performing CT examinations at four of seven brachytherapy fractions reduced the uncertainty to 4 and 7% for the bladder and rectal doses, respectively. A linear regression analysis showed a significant, negative relationship between time after treatment start and the whole bladder volume (P=0.018), whereas no correlation was found for the rectum. For both rectum and bladder a linear regression analysis revealed a significant, negative relationship between the whole volume and median dose (P<0.05). Conclusion: Preferably a CT examination should be provided at every fraction. However, this is logistically unfeasible in most institutions. To obtain reliable DVHs the patients will in the future undergo 3-4 CT examinations during the course of brachytherapy at our institution. Since this study showed an association between large bladder volumes and dose reductions, the patients will be treated with a standardized bladder volume

  3. Medium-dose-rate intracavitary brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Tanaka, Eiichi; Isohashi, Fumiaki; Oh, Ryoong-Jin

    2003-01-01

    The purpose of this study was to evaluate the results of medium-dose-rate (MDR) intracavitary brachytherapy (ICRT) for cervical cancer. Between May 1991 and March 2001, 80 patients with cervical cancer were treated with external radiotherapy combined with MDR-ICRT. Two patients were excluded from this study. The median age of patients was 61 years (range: 30-87 years). Seventy-five patients had pathologically proved squamous cell carcinoma, and 3 had adenocarcinoma. The patients were staged by Union Internationale Contre le Cancer (UICC) classification as follows: Stage IA (2), Stage IB (4), Stage IIA (5), Stage IIB (22), Stage IIIA (1), Stage IIIB (32), Stage IVA (5), Stage IVB (7). Median follow-up for survivor was 68 months (range: 12-131 months). The radiation therapy was based on a combination of ICRT and external pelvic irradiation. Patients with stages II, III and IVA were treated with whole-pelvic irradiation with respective total doses of 20, 30, and 40 Gy. Doses of 40, 30, 20, and 20 Gy parametrial irradiation were added with central shield pelvic irradiation for stages IB, II, III and IVA lesions respectively. For MDR-ICRT, from May 1991 to December 1995, point A dose were 40 Gy/4 fractions for stages I and II, 38 Gy/4 fractions for stage III, and 28.5 Gy/3 fractions for stage IVA. And from January 1996 to March 2001, point A dose of 36 Gy/4 fractions for stages I and II, 34 Gy/4 fractions for stage III, and 25.5 Gy/3 fractions for stage IVA. The median dose rate at point A was 1.7 Gy/hour (range: 1.3-2.2 Gy/hour). The 5-year cause-specific survival rates were 100%, 76%, 51% and 40% for stages I, II, III and IVA respectively. All patients with stage IVB died from the tumor with a median survival time of 12 months. The 5-year pelvic control rates were 100%, 88%, 69% and 40% for stages I, II, III and IVA respectively. Major late complications occurred in 2 patients (3%). One patient developed vesico- and recto-vaginal fistulae, and died of pelvic infection

  4. Urethral stricture following high dose rate brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Sullivan, Lisa; Williams, Scott G.; Tai, Keen Hun; Foroudi, Farshad; Cleeve, L.; Duchesne, Gillian M.

    2009-01-01

    Purpose: To evaluate the incidence, timing, nature and outcome of urethral strictures following high dose rate brachytherapy (HDRB) for prostate carcinoma. Methods and materials: Data from 474 patients with clinically localised prostate cancer treated with HDRB were analysed. Ninety percent received HDRB as a boost to external beam radiotherapy (HDRBB) and the remainder as monotherapy (HDRBM). Urethral strictures were graded according to the Common Terminology Criteria for Adverse Events v3.0. Results: At a median follow-up of 41 months, 38 patients (8%) were diagnosed with a urethral stricture (6-year actuarial risk 12%). Stricture location was bulbo-membranous (BM) urethra in 92.1%. The overall actuarial rate of grade 2 or more BM urethral stricture was estimated at 10.8% (95% CI 7.0-14.9%), with a median time to diagnosis of 22 months (range 10-68 months). All strictures were initially managed with either dilatation (n = 15) or optical urethrotomy (n = 20). Second line therapy was required in 17 cases (49%), third line in three cases (9%) and 1 patient open urethroplasty (grade 3 toxicity). Predictive factors on multivariate analysis were prior trans-urethral resection of prostate (hazard ratio (HR) 2.81, 95% CI 1.15-6.85, p = 0.023); hypertension (HR 2.83, 95% CI 1.37-5.85, p = 0.005); and dose per fraction used in HDR (HR for 1 Gy increase per fraction 1.33, 95% CI 1.08-1.64, p = 0.008). Conclusions: BM urethral strictures are the most common late grade 2 or more urinary toxicity following HDR brachytherapy for prostate cancer. Most are manageable with minimally invasive procedures. Both clinical and dosimetric factors appear to influence the risk of stricture formation.

  5. Prostate-specific antigen bounce after high-dose rate brachytherapy with external beam radiation therapy for prostate cancer patients

    International Nuclear Information System (INIS)

    Sakamoto, Naotaka; Kakinoki, Hiroaki; Tsutsui, Akio; Yoshikawa, Masahiro; Iguchi, Atsushi; Matsunobu, Toru; Uehara, Satoru

    2008-01-01

    Prostate-specific antigen (PSA) bounce after high-dose rate (HDR) brachytherapy with external beam radiation therapy (EBRT) for prostate cancer patients was evaluated. Sixty-one patients treated with HDR-brachytherapy followed by EBRT had a minimum follow-up of 12 months (median, 24 months) in our institute. A PSA bounce was defined as a rise of at least 0.1 ng/ml greater than a previous PSA level, with a subsequent decline equal to, or less than, the initial nadir. A PSA bounce was noted in 16 (26.2%) of 61 patients (one patient had a PSA bounce twice). Median time to develop a PSA bounce was 18 months, but 23.5% developed a PSA bounce after 24 months. Median duration of PSA bounce was 6 months and 11.8% had increased PSA within a period of 12 months. Median bounce height was 0.2 ng/ml (range, 0.1 to 3.39 ng/ml). A bounce height of gerater than 2 ng/ml was seen in 11.8%. Clinical characteristics (age, prostate volume, neoadjuvant endocrine therapy, risk classification, stage, pretreatment PSA, Gleason score) do not predict whether or not there will be a PSA bounce. In patients treated with HDR-brachytherapy followed by EBRT, the incidence and characteristics of PSA bounce were similar to those in patients treated with low-dose rate brachytherapy. Physicians should be aware of the possibility of PSA bounce following HDR-brachytherapy with EBRT. (author)

  6. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy.

    Directory of Open Access Journals (Sweden)

    Luciana Tourinho Campos

    Full Text Available The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®; it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86, which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21, which is also from BEBIG.The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the photoelectric effect, pair

  7. Late change of normal tissue treated either by high dose rate or low dose rate interstitial brachytherapy. A retrospective comparative study on oral and oropharyngeal mucosa

    International Nuclear Information System (INIS)

    Nose, Takayuki; Koizumi, Masahiko; Nishiyama, Kinji; Inoue, Toshihiko

    2002-01-01

    The purpose of this study was to compare late changes of normal tissue treated either by high dose rate (HDR) or low dose rate (LDR) interstitial brachytherapy. For HDR group, 22 oropharynx cancer patients who were treated by HDR Ir-192 interstitial brachytherapy with/without external beam radiotherapy in Osaka (Osaka Medical Center for Cancer and Cardiovascular Diseases and Osaka University Hospital) during June 1994 through April 2000 and came to the follow-up clinics during July 2000 through December 2000 were studied. For LDR group, 26 oropharynx cancer patients who were treated by LDR Ir-192 interstitial brachytherapy with/without external beam radiotherapy in Nancy (Centre Alexis Vautrin) during February 1989 through July 1998 and came to the follow-up clinics during April 1999 through July 1999 were studied. The standard HDR schedules were 54 Gy/9 fr/5-6 days for monotherapy and 18-24 Gy/3-4 fr/2-3 days following 45 Gy external beam radiotherapy. The standard LDR schedules were 65 Gy/5-6 days for monotherapy and 15-25 Gy/2-3 days following 50 Gy external beam radiotherapy. For evaluation of the late changes, we scored the mucosal and muscular changes inside the treated volume using the modified Dische score system and the RTOG/EORTC late radiation morbidity scoring scheme. For 6 items of the modified Dische score system, no significant difference was found between HDR and LDR groups. For the remaining 2 items (pallor, mobility impairment of faucial pillars), LDR group showed higher scores (p=0.010, 0.002). LDR group showed a trend toward higher scores for the RTOG/EORTC scheme (p=0.059). Some predict late effects by HDR interstitial brachytherapy to be severer than by LDR because no dose-rate effects can be expected. Our study, however, showed at least equivalent or even milder late changes by HDR. Appropriate fractionation schedule and extra geometrical sparing effects by optimized dose distribution of HDR group might result in milder late changes. With our

  8. Biological effect of Pulsed Dose Rate brachytherapy with stepping sources

    International Nuclear Information System (INIS)

    Limbergen, Erik F.M. van; Fowler, Jack F.

    1996-01-01

    Purpose: To explore the possible increase of radiation effect in tissues irradiated by pulsed brachytherapy (PDR), for local tissue dose-rates between those 'averaged over the whole pulse' and the instantaneous high dose rates close to the dwell positions. An earlier publication (Fowler and Mount 1992) had shown that, for dose rates (averaged for the duration of the pulse) up to 3 Gy/h, little change of isoeffect doses from continuous low dose rate (CLDR) are expected, unless larger doses per fraction than 1 Gy are used, and especially if components of very rapid repair are present with half-times of less than about 0.5 hours. However, local and transient dose rates close to stepping sources can be up to several Gy per minute. Methods: Calculations were done assuming the linear quadratic formula for radiation damage, in which only the dose-squared term is subject to repair, at a constant exponential rate. The formula developed by Dale for fractionated low-dose-rate radiotherapy was used. A constant overall time of 140 hours and constant total dose of 70 Gy were assumed throughout, the continuous low dose-rate of 0.5 Gy/h (CLDR) providing the unitary standard effects for each PDR condition. Effects of dose-rates ranging from 4 Gy/h to 120 Gy/h (HDR at 2 Gy/min) were studied, and T (1(2)) from 4 minutes to 1.5 hours. Results: Curves are presented relating the ratio of increased biological effect (proportional to log cell kill) calculated for PDR relative to CLDR. Ratios as high as 1.5 can be found for large doses per pulse (> 1 Gy) at high instantaneous dose-rates if T (1(2)) in tissues is as short as a few minutes. The major influences on effect are dose per pulse, half-time of repair in the tissue, and - when T (1(2)) is short - the instantaneous dose-rate. Maximum ratios of PDR/CLDR effect occur when the dose-rate is such that pulse duration is approximately equal to T (1(2)) of repair. Results are presented for late-responding tissues, the differences from CLDR

  9. Non-uniform dwell times in line source high dose rate brachytherapy: physical and radiobiological considerations

    International Nuclear Information System (INIS)

    Jones, B.; Tan, L.T.; Freestone, G.; Bleasdale, C.; Myint, S.; Littler, J.

    1994-01-01

    The ability to vary source dwell times in high dose rate (HDR) brachytherapy allows for the use of non-uniform dwell times along a line source. This may have advantages in the radical treatment of tumours depending on individual tumour geometry. This study investigates the potential improvements in local tumour control relative to adjacent normal tissue isoeffects when intratumour source dwell times are increased along the central portion of a line source (technique A) in radiotherapy schedules which include a relatively small component of HDR brachytherapy. Such a technique is predicted to increase the local control for tumours of diameters ranging between 2 cm and 4 cm by up to 11% compared with a technique in which there are uniform dwell times along the line source (technique B). There is no difference in the local control rates for the two techniques when used to treat smaller tumours. Normal tissue doses are also modified by the technique used. Technique A produces higher normal tissue doses at points perpendicular to the centre of the line source and lower dose at points nearer the ends of the line source if the prescription point is not in the central plane of the line source. Alternatively, if the dose is prescribed at a point in the central plane of the line source, the dose at all the normal tissue points are lower when technique A is used. (author)

  10. Modulation of toxicity following external beam irradiation preceded by high-dose rate brachytherapy in inoperable oesophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Taal, B.G.; Aleman, B.M.P.; Koning, C.C.E.; Boot, H. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands)

    1996-09-01

    To induce fast relief of dysphagia in inoperable oesephageal cancer, we applied high-dose rate (HDR) intraluminal irradiation followed by external irradiation (EBRT) in a phase II study. 15 patients (group A: n = 15; 10 men, 5 women; median age 66 years) were treated with 10 Gy HDR brachytherapy plus 40 Gy EBRT (15 fractions of 2.67 Gy). Severe side-effects were encountered in 60% of patients: 3 late ulceration, 2 pending fistula and 2 patients with fatal haemorrhage after an interval of 6 months. Overall response was excellent: 9 complete remissions (60%) and 6 partial responses (40%). Because of the high toxicity rate, in a subsequent study (group B: n = 30; 23 mean, 7 women; median age 66 years) the EBRT scheme was changed using smaller fractions (2.0 Gy) to reach the same total dose of 40 Gy. The complication rate (17%) was significantly reduced, while the overall response remained excellent (83%): 17 complete and 8 partial responses. The impressive change in complication rate of HDR brachytherapy and EBRT stresses the impact of the fraction per dose and illustrates the small therapeutic margins. (author).

  11. Modulation of toxicity following external beam irradiation preceded by high-dose rate brachytherapy in inoperable oesophageal cancer

    International Nuclear Information System (INIS)

    Taal, B.G.; Aleman, B.M.P.; Koning, C.C.E.; Boot, H.

    1996-01-01

    To induce fast relief of dysphagia in inoperable oesephageal cancer, we applied high-dose rate (HDR) intraluminal irradiation followed by external irradiation (EBRT) in a phase II study. 15 patients (group A: n = 15; 10 men, 5 women; median age 66 years) were treated with 10 Gy HDR brachytherapy plus 40 Gy EBRT (15 fractions of 2.67 Gy). Severe side-effects were encountered in 60% of patients: 3 late ulceration, 2 pending fistula and 2 patients with fatal haemorrhage after an interval of 6 months. Overall response was excellent: 9 complete remissions (60%) and 6 partial responses (40%). Because of the high toxicity rate, in a subsequent study (group B: n = 30; 23 mean, 7 women; median age 66 years) the EBRT scheme was changed using smaller fractions (2.0 Gy) to reach the same total dose of 40 Gy. The complication rate (17%) was significantly reduced, while the overall response remained excellent (83%): 17 complete and 8 partial responses. The impressive change in complication rate of HDR brachytherapy and EBRT stresses the impact of the fraction per dose and illustrates the small therapeutic margins. (author)

  12. Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

    Science.gov (United States)

    Palmer, Antony L.; Lee, Chris; Ratcliffe, Ailsa J.; Bradley, David; Nisbet, Andrew

    2013-10-01

    A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit.

  13. Design and implementation of a film dosimetry audit tool for comparison of planned and delivered dose distributions in high dose rate (HDR) brachytherapy

    International Nuclear Information System (INIS)

    Palmer, Antony L; Bradley, David; Nisbet, Andrew; Lee, Chris; Ratcliffe, Ailsa J

    2013-01-01

    A novel phantom is presented for ‘full system’ dosimetric audit comparing planned and delivered dose distributions in HDR gynaecological brachytherapy, using clinical treatment applicators. The brachytherapy applicator dosimetry test object consists of a near full-scatter water tank with applicator and film supports constructed of Solid Water, accommodating any typical cervix applicator. Film dosimeters are precisely held in four orthogonal planes bisecting the intrauterine tube, sampling dose distributions in the high risk clinical target volume, points A and B, bladder, rectum and sigmoid. The applicator position is fixed prior to CT scanning and through treatment planning and irradiation. The CT data is acquired with the applicator in a near clinical orientation to include applicator reconstruction in the system test. Gamma analysis is used to compare treatment planning system exported RTDose grid with measured multi-channel film dose maps. Results from two pilot audits are presented, using Ir-192 and Co-60 HDR sources, with a mean gamma passing rate of 98.6% using criteria of 3% local normalization and 3 mm distance to agreement (DTA). The mean DTA between prescribed dose and measured film dose at point A was 1.2 mm. The phantom was funded by IPEM and will be used for a UK national brachytherapy dosimetry audit. (paper)

  14. Predictors of Toxicity After Image-guided High-dose-rate Interstitial Brachytherapy for Gynecologic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Larissa J. [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (United States); Viswanathan, Akila N., E-mail: aviswanathan@lroc.harvard.edu [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (United States)

    2012-12-01

    Purpose: To identify predictors of grade 3-4 complications and grade 2-4 rectal toxicity after three-dimensional image-guided high-dose-rate (HDR) interstitial brachytherapy for gynecologic cancer. Methods and Materials: Records were reviewed for 51 women (22 with primary disease and 29 with recurrence) treated with HDR interstitial brachytherapy. A single interstitial insertion was performed with image guidance by computed tomography (n = 43) or magnetic resonance imaging (n = 8). The median delivered dose in equivalent 2-Gy fractions was 72.0 Gy (45 Gy for external-beam radiation therapy and 24 Gy for brachytherapy). Toxicity was reported according to the Common Toxicity Criteria for Adverse Events. Actuarial toxicity estimates were calculated by the Kaplan-Meier method. Results: At diagnosis, the median patient age was 62 years and the median tumor size was 3.8 cm. The median D90 and V100 were 71.4 Gy and 89.5%; the median D2cc for the bladder, rectum, and sigmoid were 64.6 Gy, 61.0 Gy, and 52.7 Gy, respectively. The actuarial rates of all grade 3-4 complications at 2 years were 20% gastrointestinal, 9% vaginal, 6% skin, 3% musculoskeletal, and 2% lymphatic. There were no grade 3-4 genitourinary complications and no grade 5 toxicities. Grade 2-4 rectal toxicity was observed in 10 patients, and grade 3-4 complications in 4; all cases were proctitis with the exception of 1 rectal fistula. D2cc for rectum was higher for patients with grade 2-4 (68 Gy vs 57 Gy for grade 0-1, P=.03) and grade 3-4 (73 Gy vs 58 Gy for grade 0-2, P=.02) rectal toxicity. The estimated dose that resulted in a 10% risk of grade 2-4 rectal toxicity was 61.8 Gy (95% confidence interval, 51.5-72.2 Gy). Discussion: Image-guided HDR interstitial brachytherapy results in acceptable toxicity for women with primary or recurrent gynecologic cancer. D2cc for the rectum is a reliable predictor of late rectal complications. Three-dimensional-based treatment planning should be performed to ensure

  15. Implementation of microsource high dose rate (mHDR) brachytherapy in developing countries

    International Nuclear Information System (INIS)

    2001-11-01

    Brachytherapy using remote afterloading of a single high dose rate 192 Ir microsource was developed in the 1970s. After its introduction to clinics, this system has spread rapidly among developed Member States and has become a highly desirable modality in cancer treatment. This technique is now gradually being introduced to the developing Member States. The 192 Ir sources are produced with a high specific activity. This results in a high dose rate (HDR) to the tumour and shorter treatment times. The high specific activity simultaneously results in a much smaller source (so-called micro source, around I mm in diameter) which may be easily inserted into tissue through a thin delivery tube, the so-called interstitial treatment, as well as easily inserted into body cavities, the so-called intracavitary or endoluminal treatment. Another advantage is the ability to change dwell time (the time a source remains in one position) of the stepping source which allows dose distribution to match the target volume more closely. The purpose of this TECDOC is to advise radiation oncologists, medical physicists and hospital administrators in hospitals which are planning to introduce 192 Ir microsource HDR (mHDR) remote afterloading systems. The document supplements IAEA-TECDOC-1040, Design and Implementation of a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects, and will facilitate implementation of this new brachytherapy technology, especially in developing countries. The operation of the system, 'how to use the system', is not within the scope of this document. This TECDOC is based on the recommendations of an Advisory Group meeting held in Vienna in April 1999

  16. Acute genitourinary toxicity after high-dose-rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: Correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Ito, Kazuto; Saitoh, Jun-ichi; Noda, Shin-ei; Harashima, Koichi; Sakurai, Hideyuki; Nakayama, Yuko; Yamamoto, Takumi; Suzuki, Kazuhiro; Nakano, Takashi; Niibe, Hideo

    2005-01-01

    Purpose: Several investigations have revealed that the α/β ratio for prostate cancer is atypically low, and that hypofractionation or high-dose-rate (HDR) brachytherapy regimens using appropriate radiation doses may be expected to yield tumor control and late sequelae rates that are better or at least as favorable as those achieved with conventional radiation therapy. In this setting, we attempted treating localized prostate cancer patients with HDR brachytherapy combined with hypofractionated external beam radiation therapy (EBRT). The purpose of this study was to evaluate the feasibility of using this approach, with special emphasis on the relationship between the severity of acute genitourinary (GU) toxicity and the urethral dose calculated from the dose-volume histogram (DVH) of HDR brachytherapy. Methods and Materials: Between September 2000 and December 2003, 70 patients with localized prostate cancer were treated by iridium-192 HDR brachytherapy combined with hypofractionated EBRT at the Gunma University Hospital. Hypofractionated EBRT was administered in fraction doses of 3 Gy, three times per week; a total dose of 51 Gy was delivered to the prostate gland and the seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography (TRUS)-guided HDR brachytherapy. The fraction size and the number of fractions in HDR brachytherapy were prospectively changed, whereas the total radiation dose for EBRT was fixed at 51 Gy. The fractionation in HDR brachytherapy was as follows: 5 Gy x 5, 7 Gy x 3, 9 Gy x 2, administered twice per day, although the biologic effective dose (BED) for HDR brachytherapy combined with EBRT, assuming that the α/β ratio is 3, was almost equal to 138 in each fractionation group. The planning target volume was defined as the prostate gland with 5-mm margin all around, and the planning was conducted based on

  17. Sci-Thur PM – Brachytherapy 06: 3D Printed Surface Applicators for High Dose Rate Brachytherapy

    International Nuclear Information System (INIS)

    Clarke, Scott; Yewondwossen, Mammo; Robar, James

    2016-01-01

    Purpose: The purpose of this work is to develop a new applicator for administering high dose rate (HDR) brachytherapy using 3D printing technology. Primary advantages of using a 3D printed applicator will be to offer a more streamlined approach for therapists and patients while achieving better conformity, reproducibility, and patient specific applicators. Methods: A phantom study was conducted to measure the effectiveness of a 3D printed surface applicator by analyzing tumours on three locations of the body: the foot, nose, and scalp. The applicator was designed using Eclipse and further modified using Blender to create the catheter tunnels before being printed on a Lulzbot Taz 5 3D printer. A radiation plan was made using Oncentra Brachytherapy for a control treatment option using Freiburg Flaps and one with the novel method of a 3D printed applicator. A comparative analysis was made using D90, D100, V100, V150, and V200 Results: The 3D printed applicator showed comparable dose coverage with significant improvements on highly irregular surfaces when analyzed against a plan made using Freiburg Flaps. Although both plans exhibited complete tumour coverage, the 3D applicator showed improvements in D90 and V150 and the 3D applicator had a dose homogeneity index (DHI) of 0.99 compared to a DHI of 0.97 for the control. Therapist prep time also dropped significantly due to the lack of need for a thermoplastic mesh. Conclusions: 3D printed applicators for treatment of superficial sites proved to offer more patient convenience, less prep time, better conformity and tighter margins.

  18. Sci-Thur PM – Brachytherapy 06: 3D Printed Surface Applicators for High Dose Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Scott; Yewondwossen, Mammo; Robar, James [Dalhousie University, Nova Scotia Cancer Centre, Capital District Health Authority (Canada)

    2016-08-15

    Purpose: The purpose of this work is to develop a new applicator for administering high dose rate (HDR) brachytherapy using 3D printing technology. Primary advantages of using a 3D printed applicator will be to offer a more streamlined approach for therapists and patients while achieving better conformity, reproducibility, and patient specific applicators. Methods: A phantom study was conducted to measure the effectiveness of a 3D printed surface applicator by analyzing tumours on three locations of the body: the foot, nose, and scalp. The applicator was designed using Eclipse and further modified using Blender to create the catheter tunnels before being printed on a Lulzbot Taz 5 3D printer. A radiation plan was made using Oncentra Brachytherapy for a control treatment option using Freiburg Flaps and one with the novel method of a 3D printed applicator. A comparative analysis was made using D90, D100, V100, V150, and V200 Results: The 3D printed applicator showed comparable dose coverage with significant improvements on highly irregular surfaces when analyzed against a plan made using Freiburg Flaps. Although both plans exhibited complete tumour coverage, the 3D applicator showed improvements in D90 and V150 and the 3D applicator had a dose homogeneity index (DHI) of 0.99 compared to a DHI of 0.97 for the control. Therapist prep time also dropped significantly due to the lack of need for a thermoplastic mesh. Conclusions: 3D printed applicators for treatment of superficial sites proved to offer more patient convenience, less prep time, better conformity and tighter margins.

  19. Impact of 'optimized' treatment planning for tandem and ring, and tandem and ovoids, using high dose rate brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Noyes, William R.; Peters, Nancy E.; Thomadsen, Bruce R.; Fowler, Jack F.; Buchler, Dolores A.; Stitt, Judith A.; Kinsella, Timothy J.

    1995-01-01

    Purpose: Different treatment techniques are used in high dose rate (HDR) remote afterloading intracavitary brachytherapy for uterine cervical cancer. We have investigated the differences between 'optimized' and 'nonoptimized' therapy using both a tandem and ring (T/R) applicator, and a tandem and ovoids (T/O), applicator. Methods and Materials: HDR afterloading brachytherapy using the Madison System for Stage IB cervical cancer was simulated for 10 different patients using both a T/R applicator and a T/O applicator. A treatment course consists of external beam irradiation and five insertions of HDR afterloading brachytherapy. Full dosimetry calculations were performed at the initial insertion for both applicators and used as a reference for the following four insertions of the appropriate applicator. Forty dosimetry calculations were performed to determine the dose delivered to Point M (similar to Point A), Point E (obturator lymph nodes), vaginal surface, bladder, and rectum. 'Optimized' doses were specified to Point M and to the vaginal surface. 'Nonoptimized' doses were specified to Point M only. Using the linear-quadratic equation, calculations have been performed to convert the delivered dose using HDR to the biologically equivalent doses at the conventional low dose rate (LDR) at 0.60 Gy/h. Results: Major differences between 'optimized' and 'nonoptimized' LDR equivalent doses were found at the vaginal surface, bladder, and rectum. Overdoses at the vaginal surface, bladder, and rectum were calculated to be 208%, nil, and 42%, respectively, for the T/R applicator with 'nonoptimization'. However, for the T/O applicator, the overdoses were smaller, being nil, 32%, and 27%, respectively, with 'nonoptimization'. Conclusion: Doses given in high dose rate intracavitary brachytherapy border on tissue tolerance. 'Optimization' of either applicator decreases the risk of a dose that may have potential for complications. Optimization of a tandem and ovoids best ensures

  20. High-dose-rate brachytherapy as salvage modality for locally recurrent prostate cancer after definitive radiotherapy. A systematic review

    International Nuclear Information System (INIS)

    Chatzikonstantinou, Georgios; Zamboglou, Nikolaos; Roedel, Claus; Tselis, Nikolaos; Zoga, Eleni; Strouthos, Iosif; Butt, Saeed Ahmed

    2017-01-01

    To review the current status of interstitial high-dose-rate brachytherapy as a salvage modality (sHDR BRT) for locally recurrent prostate cancer after definitive radiotherapy (RT). A literature search was performed in PubMed using ''high-dose-rate, brachytherapy, prostate cancer, salvage'' as search terms. In all, 51 search results published between 2000 and 2016 were identified. Data tables were generated and summary descriptions created. The main outcome parameters used were biochemical control (BC) and toxicity scores. Eleven publications reported clinical outcome and toxicity with follow-up ranging from 4-191 months. A variety of dose and fractionation schedules were described, including 19.0 Gy in 2 fractions up to 42.0 Gy in 6 fractions. The 5-year BC ranged from 18-77%. Late grade 3 genitourinary and gastrointestinal toxicity was 0-32% and 0-5.1%, respectively. sHDR BRT appears as safe and effective salvage modality for the reirradiation of locally recurrent prostate cancer after definitive RT. (orig.) [de

  1. Adjuvant high dose rate vaginal cuff brachytherapy for early stage endometrial cancer

    International Nuclear Information System (INIS)

    Tannehill, S.P.; Petereit, D.G.; Schink, J.C.; Grosen, E.A.; Hartenbach, E.M.; Thomadsen, B.R.; Buchler, D.A.

    1997-01-01

    Objective: To determine the efficacy and complications of adjuvant high dose rate (HDR) vaginal cuff brachytherapy (VCB) in patients (pts) with low risk endometrial carcinoma. Materials and Methods: Since 1989, 154 patients were treated with outpatient adjuvant VCB for low risk endometrial cancer (Stage IA-14%, Stage IB-82%). Four percent of patients with stage IC disease were treated with VCB only because of medical contraindications to pelvic radiation. Patients had the following histologic grades: 53% grade 1, 40% grade 2, 5% grade 3 and 3% unknown (99%-adenocarcinoma, <1% papillary serous histology). Seventy-three percent of patients had their surgery (TAH-BSO) performed at an outside institution with minimal surgical assessment of the lymph nodes. At a median of 6 weeks after surgery, patients were treated with 2 HDR VCB insertions delivered 1 week apart. Ovoids were placed at the vaginal apex to deliver 16.2 Gy per fraction to the vaginal surface (LDR equivalent of 60 Gy at 100 cGy/h) under conscious outpatient sedation. All clinical endpoints were calculated using the Kaplan Meier method. Complications were scored using the RTOG 5-tiered system. Results: The median time in the brachytherapy suite was 60 minutes with no acute complications observed. With a median follow-up of 33 months (3-79 months), the 4-year overall and disease-free survival were 93% and 96% respectively. Five patients (3%) recurred: 2 intra-abdominally, 1 with lung metastases, and 2 in the pelvic lymph nodes. There were no vaginal cuff recurrences. The single patient with an isolated pelvic sidewall recurrence was salvaged with pelvic RT. Six patients developed a small area of asymptomatic necrosis at the vaginal cuff, which spontaneously healed at a median time of 4 months. There were no grade 3 or greater late tissue toxicities. No patient experienced significant vaginal stenosis, with 20% of the patients experiencing mild fibrosis of the vaginal apex. Conclusions: Adjuvant HDR VCB in 2

  2. High Dose Rate Brachytherapy in Two 9 Gy Fractions in the Treatment of Locally Advanced Cervical Cancer - a South Indian Institutional Experience.

    Science.gov (United States)

    Ghosh, Saptarshi; Rao, Pamidimukkala Bramhananda; Kotne, Sivasankar

    2015-01-01

    Although 3D image based brachytherapy is currently the standard of treatment in cervical cancer, most of the centres in developing countries still practice orthogonal intracavitary brachytherapy due to financial constraints. The quest for optimum dose and fractionation schedule in high dose rate (HDR) intracavitary brachytherapy (ICBT) is still ongoing. While the American Brachytherapy Society recommends four to eight fractions of each less than 7.5 Gy, there are some studies demonstrating similar efficacy and comparable toxicity with higher doses per fraction. To assess the treatment efficacy and late complications of HDR ICBT with 9 Gy per fraction in two fractions. This is a prospective institutional study in Southern India carried on from 1st June 2012 to 31st July 2014. In this period, 76 patients of cervical cancer satisfying our inclusion criteria were treated with concurrent chemo-radiation following ICBT with 9 Gy per fraction in two fractions, five to seven days apart. The median follow-up period in the study was 24 months (range 10.6 - 31.2 months). The 2 year actuarial local control rate, disease-free survival and overall survival were 88.1%, 84.2% and 81.8% respectively. Although 38.2% patients suffered from late toxicity, only 3 patients had grade III late toxicity. In our experience, HDR brachytherapy with 9 Gy per fraction in two fractions is an effective dose fractionation for the treatment of cervical cancer with acceptable toxicity.

  3. Suitability of point kernel dose calculation techniques in brachytherapy treatment planning

    Directory of Open Access Journals (Sweden)

    Lakshminarayanan Thilagam

    2010-01-01

    Full Text Available Brachytherapy treatment planning system (TPS is necessary to estimate the dose to target volume and organ at risk (OAR. TPS is always recommended to account for the effect of tissue, applicator and shielding material heterogeneities exist in applicators. However, most brachytherapy TPS software packages estimate the absorbed dose at a point, taking care of only the contributions of individual sources and the source distribution, neglecting the dose perturbations arising from the applicator design and construction. There are some degrees of uncertainties in dose rate estimations under realistic clinical conditions. In this regard, an attempt is made to explore the suitability of point kernels for brachytherapy dose rate calculations and develop new interactive brachytherapy package, named as BrachyTPS, to suit the clinical conditions. BrachyTPS is an interactive point kernel code package developed to perform independent dose rate calculations by taking into account the effect of these heterogeneities, using two regions build up factors, proposed by Kalos. The primary aim of this study is to validate the developed point kernel code package integrated with treatment planning computational systems against the Monte Carlo (MC results. In the present work, three brachytherapy applicators commonly used in the treatment of uterine cervical carcinoma, namely (i Board of Radiation Isotope and Technology (BRIT low dose rate (LDR applicator and (ii Fletcher Green type LDR applicator (iii Fletcher Williamson high dose rate (HDR applicator, are studied to test the accuracy of the software. Dose rates computed using the developed code are compared with the relevant results of the MC simulations. Further, attempts are also made to study the dose rate distribution around the commercially available shielded vaginal applicator set (Nucletron. The percentage deviations of BrachyTPS computed dose rate values from the MC results are observed to be within plus/minus 5

  4. Low-dose-rate intraoperative brachytherapy combined with external beam irradiation in the conservative treatment of soft tissue sarcoma

    International Nuclear Information System (INIS)

    Delannes, M.; Thomas, L.; Martel, P.; Bonnevialle, P.; Stoeckle, E.; Chevreau, Ch.; Bui, B.N.; Daly-Schveitzer, N.; Pigneux, J.; Kantor, G.

    2000-01-01

    Purpose: Conservative treatment of soft tissue sarcomas most often implies combination of surgical resection and irradiation. The aim of this study was to evaluate low-dose-rate intraoperative brachytherapy, delivered as a boost, in the local control of primary tumors, with special concern about treatment complications. Methods and Materials: Between 1986 and 1995, 112 patients underwent intraoperative implant. This report focuses on the group of 58 patients with primary sarcomas treated by combination of conservative surgery, intraoperative brachytherapy, and external irradiation. Most of the tumors were located in the lower limbs (46/58--79%). Median size of the tumor was 10 cm, most of the lesions being T2-T3 (51/58--88%), Grade 2 or 3 (48/58--83%). The mean brachytherapy dose was 20 Gy and external beam irradiation dose 45 Gy. In 36/58 cases, iridium wires had to be placed on contact with neurovascular structures. Results: With a median follow-up of 54 months, the 5-year actuarial survival was 64.9%, with a 5-year actuarial local control of 89%. Of the 6 patients with local relapse, 3 were salvaged. Acute side effects, essentially wound healing problems, occurred in 20/58 patients, late side effects in 16/58 patients (7 neuropathies G2 to G4). No amputation was required. The only significant factor correlated with early side effects was the location of the tumor in the lower limb (p = 0.003), and with late side effects the vicinity of the tumor with neurovascular structures (p = 0.009). Conclusion: Brachytherapy allows early delivery of a boost dose in a reduced volume of tissue, precisely mapped by the intraoperative procedure. Combined with external beam irradiation, it is a safe and efficient treatment technique leading to high local control rates and limited functional impairment

  5. Toward a 'all high rate' brachytherapy: organisation, biology and perspectives after treatment of 192 patients

    International Nuclear Information System (INIS)

    Hannoun-Levi, J.M.; Ferre, M.; Gautier, M.; Marcie, S.

    2007-01-01

    As a result of radiation protection regulations aimed at reducing the exposure to ionizing radiation from care-givers, low dose rate brachytherapy is usually replaced by a pulsed rate brachytherapy. The center Antoine Lacassagne has directed the outset to the use of a high-dose rate brachytherapy. The implications in terms of organization, biology and the prospects for such a change are the principal questions studied. (N.C.)

  6. Post-operative high dose rate brachytherapy in patients with low to intermediate risk endometrial cancer

    International Nuclear Information System (INIS)

    Pearcey, R.G.; Petereit, D.G.

    2000-01-01

    This paper investigates the outcome using different dose/fractionation schedules in high dose rate (HDR) post-operative vaginal vault radiotherapy in patients with low to intermediate risk endometrial cancer. The world literature was reviewed and thirteen series were analyzed representing 1800 cases. A total of 12 vaginal vault recurrences were identified representing an overall vaginal control rate of 99.3%. A wide range of dose fractionation schedules and techniques have been reported. In order to analyze a dose response relationship for tumor control and complications, the biologically effective doses to the tumor and late responding tissues were calculated using the linear quadratic model. A threshold was identified for complications, but not vaginal control. While dose fractionation schedules that delivered a biologically effective dose to the late responding tissues in excess of 100 Gy 3 (LQED = 60 Gy) predicted for late complications, dose fractionation schedules that delivered a modest dose to the vaginal surface (50 Gy 10 or LQED = 30 Gy) appeared tumoricidal with vaginal control rates of at least 98%. By using convenient, modest dose fractionation schedules, HDR vaginal vault - brachytherapy yields very high local control and extremely low morbidity rates. (author)

  7. Comparison of absorbed dose in the cervix carcinoma therapy by brachytherapy of high dose rate using the conventional planning and Monte Carlo simulation

    International Nuclear Information System (INIS)

    Silva, Aneli Oliveira da

    2010-01-01

    This study aims to compare the doses received for patients submitted to brachytherapy High Dose Rate (HDR) brachytherapy, a method of treatment of the cervix carcinoma, performed in the planning system PLATO BPS with the doses obtained by Monte Carlo simulation using the radiation transport code MCNP 5 and one female anthropomorphic phantom based on voxel, the FAX. The implementation of HDR brachytherapy treatment for the cervix carcinoma consists of the insertion of an intrauterine probe and an intravaginal probe (ring or ovoid) and then two radiographs are obtained, anteroposterior (AP) and lateral (LAT) to confirm the position of the applicators in the patient and to allow the treatment planning and the determination of the absorbed dose at points of interest: rectum, bladder, sigmoid and point A, which corresponds anatomically to the crossings of the uterine arteries with ureters The absorbed doses obtained with the code MCNP 5, with the exception of the absorbed dose in the rectum and sigmoid for the simulation considering a point source of 192 Ir, are lower than the absorbed doses from PLATO BPS calculations because the MCNP 5 considers the chemical compositions and densities of FAX body, not considering the medium as water. When considering the Monte Carlo simulation for a source with dimensions equal to that used in the brachytherapy irradiator used in this study, the values of calculated absorbed dose to the bladder, to the rectum, to the right point A and to the left point A were respectively lower than those determined by the treatment planning system in 33.29, 5.01, 22.93 and 19.04%. These values are almost all larger than the maximum acceptable deviation between patient planned and administered doses (5 %). With regard to the rectum and bladder, which are organs that must be protected, the present results are in favor of the radiological protection of patients. The point A, that is on the isodose of 100%, used to tumor treatment, the results indicate

  8. Needle migration and dosimetric impact in high-dose-rate brachytherapy for prostate cancer evaluated by repeated MRI.

    Science.gov (United States)

    Buus, Simon; Lizondo, Maria; Hokland, Steffen; Rylander, Susanne; Pedersen, Erik M; Tanderup, Kari; Bentzen, Lise

    To quantify needle migration and dosimetric impact in high-dose-rate brachytherapy for prostate cancer and propose a threshold for needle migration. Twenty-four high-risk prostate cancer patients treated with an HDR boost of 2 × 8.5 Gy were included. Patients received an MRI for planning (MRI1), before (MRI2), and after treatment (MRI3). Time from needle insertion to MRI3 was ∼3 hours. Needle migration was evaluated from coregistered images: MRI1-MRI2 and MRI1-MRI3. Dose volume histogram parameters from the treatment plan based on MRI1 were related to parameters based on needle positions in MRI2 or MRI3. Regression was used to model the average needle migration per implant and change in D90 clinical target volume, CTV prostate+3mm . The model fit was used for estimating the dosimetric impact in equivalent dose in 2 Gy fractions for dose levels of 6, 8.5, 10, 15, and 19 Gy. Needle migration was on average 2.2 ± 1.8 mm SD from MRI1-MRI2 and 5.0 ± 3.0 mm SD from MRI1-MRI3. D90 CTV prostate+3mm was robust toward average needle migration ≤3 mm, whereas for migration >3 mm D90 decreased by 4.5% per mm. A 3 mm of needle migration resulted in a decrease of 0.9, 1.7, 2.3, 4.8, and 7.6 equivalent dose in 2 Gy fractions for dose levels of 6, 8.5, 10, 15, and 19 Gy, respectively. Substantial needle migration in high-dose-rate brachytherapy occurs frequently in 1-3 hours following needle insertion. A 3-mm threshold of needle migration is proposed, but 2 mm may be considered for dose levels ≥15 Gy. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  9. Comparison of low and high dose rate brachytherapy in the treatment of uterine cervix cancer. Retrospective analysis of two sequential series

    International Nuclear Information System (INIS)

    Ferrigno, Robson; Nishimoto, Ines Nobuko; Ribeiro dos Santos Novaes, Paulo Eduardo; Pellizzon, Antonio Cassio Assis; Conte Maia, Maria Aparecida; Fogarolli, Ricardo Cesar; Salvajoli, Joao Victor

    2005-01-01

    Purpose: This retrospective analysis aims to report on the comparative outcome of cervical cancer patients treated with low dose rate (LDR) and high dose rate (HDR) brachytherapy. Methods and Materials: From 1989 to 1995, 190 patients were treated with low dose rate (LDR) brachytherapy (LDR group) and from 1994 to 2001, 118 patients were treated with high dose rate (HDR) brachytherapy (HDR group). FIGO stage distribution for the LDR group was Stage I: 6.3%; Stage II: 57.4%; and Stage III: 36.3% and for the HDR group Stage I: 9.3%; Stage II: 43.2%; and Stage III: 47.4%. All patients were treated with telecobalt external-beam radiotherapy (EBR). Median doses of LDR brachytherapy at Point A were 40 Gy and 50 Gy for patients treated with 1 and 2 implants, respectively. All patients from the HDR group were treated with 24 Gy in 4 fractions of 6 Gy to Point A. Survival, disease-free survival, local control, and late complications at 5 years, were endpoints compared for both groups. Results: Median follow-up time for LDR and HDR groups was 70 months (range, 8-127 months) and 33 months (range, 4-117 months), respectively. For all stages combined, overall survival, disease-free survival, and local control at 5 years were better in the LDR group (69% vs. 55%, p = 0.007; 73% vs. 56%, p = 0.002; and 74% vs. 65%; p = 0.04, respectively). For clinical Stages I and II, no differences was seen in overall survival, disease-free survival, and local control at 5 years between the two groups. For clinical Stage III, overall survival and disease-free survival at 5 years were better in the LDR group than in the HDR group (46% vs. 36%, p = 0.04 and 49% vs. 37%, p = 0.03, respectively), and local control was marginally higher in the LDR group than in the HDR group (58% vs. 50%, p = 0.19). The 5-year probability of rectal complications was higher in the LDR group than in the HDR group (16% vs. 8%, p = 0.03) and 5-year probability of small bowel and urinary complications was not

  10. The novel nomogram of Gleason sum upgrade: possible application for the eligible criteria of low dose rate brachytherapy.

    Science.gov (United States)

    Budäus, Lars; Graefen, Markus; Salomon, Georg; Isbarn, Hendrik; Lughezzani, Giovanni; Sun, Maxine; Chun, Felix K H; Schlomm, Thorsten; Steuber, Thomas; Haese, Alexander; Koellermann, Jens; Sauter, Guido; Fisch, Margit; Heinzer, Hans; Huland, Hartwig; Karakiewicz, Pierre I

    2010-10-01

    To examine the rate of Gleason sum upgrading (GSU) from a sum of 6 to a Gleason sum of ≥7 in patients undergoing radical prostatectomy (RP), who fulfilled the recommendations for low dose rate brachytherapy (Gleason sum 6, prostate-specific antigen ≤10 ng/mL, clinical stage ≤T2a and prostate volume ≤50 mL), and to test the performance of an existing nomogram for prediction of GSU in this specific cohort of patients. The analysis focused on 414 patients, who fulfilled the European Society for Therapeutic Radiation and Oncology and American Brachytherapy Society criteria for low dose rate brachytherapy (LD-BT) and underwent a 10-core prostate biopsy followed by RP. The rate of GSU was tabulated and the ability of available clinical and pathological parameters for predicting GSU was tested. Finally, the performance of an existing GSU nomogram was explored. The overall rate of GSU was 35.5%. When applied to LD-BT candidates, the existing nomogram was 65.8% accurate versus 70.8% for the new nomogram. In decision curve analysis tests, the new nomogram fared substantially better than the assumption that no patient is upgraded and better than the existing nomogram. GSU represents an important issue in LD-BT candidates. The new nomogram might improve patient selection for LD-BT and cancer control outcome by excluding patients with an elevated probability of GSU. © 2010 The Japanese Urological Association.

  11. Quality assurance of Vari-source high dose rate (HDR) brachytherapy- remote after loader and cost effectiveness of Vari-source HDR- brachytherapy: NORI, Islamabad experience

    International Nuclear Information System (INIS)

    Ahmad, N.; Mahmood, H.; Jafri, S.R.A.

    2004-01-01

    A quality control of Vari-Source high dose rate (HDR) remote after loading brachytherapy machine was carried out and the cost effectiveness of HDR brachytherapy machine was also evaluated considering the cost of ten Iridium-192 wire sources at Nuclear Medicine, Oncology and Radiotherapy Institute (NORI), Islamabad, Pakistan. A total number of 253 intracavitary insertions were done in 98 patients from October 1996 to May 2001. The results of the quality control tests performed during 1996 to 2001 were within the acceptable limits. The cost effectiveness of Vari-Source HDR brachytherapy machine was also evaluated. The average cost per patient was calculated as US$ 491. Small number of patients was treated as the machine was used for gynecologic malignancies only. The objective was to assess the quality control status of HDR brachytherapy machine on patient treatment day, source exchange day and periodic day (monthly basis). It was found that the cost per patient can be minimized if other type of cancer patients are also treated on Vari-Source HDR machine. (author)

  12. Polyethylene glycol hydrogel rectal spacer implantation in patients with prostate cancer undergoing combination high-dose-rate brachytherapy and external beam radiotherapy.

    Science.gov (United States)

    Yeh, Jekwon; Lehrich, Brandon; Tran, Carolyn; Mesa, Albert; Baghdassarian, Ruben; Yoshida, Jeffrey; Torrey, Robert; Gazzaniga, Michael; Weinberg, Alan; Chalfin, Stuart; Ravera, John; Tokita, Kenneth

    2016-01-01

    To present rectal toxicity rates in patients administered a polyethylene glycol (PEG) hydrogel rectal spacer in conjunction with combination high-dose-rate brachytherapy and external beam radiotherapy. Between February 2010 and April 2015, 326 prostate carcinoma patients underwent combination high-dose-rate brachytherapy of 16 Gy (average dose 15.5 Gy; standard deviation [SD] = 1.6 Gy) and external beam radiotherapy of 59.4 Gy (average dose 60.2 Gy; SD = 2.9 Gy). In conjunction with the radiation therapy regimen, each patient was injected with 10 mL of a PEG hydrogel in the anterior perirectal fat space. The injectable spacer (rectal spacer) creates a gap between the prostate and the rectum. The rectum is displaced from the radiation field, and rectal dose is substantially reduced. The goal is a reduction in rectal radiation toxicity. Clinical efficacy was determined by measuring acute and chronic rectal toxicity using the National Cancer Center Institute Common Terminology Criteria for Adverse Events v4.0 grading scheme. Median followup was 16 months. The mean anterior-posterior separation achieved was 1.6 cm (SD = 0.4 cm). Rates of acute Grade 1 and 2 rectal toxicity were 37.4% and 2.8%, respectively. There were no acute Grade 3/4 toxicities. Rates of late Grade 1, 2, and 3 rectal toxicity were 12.7%, 1.4%, and 0.7%, respectively. There were no late Grade 4 toxicities. PEG rectal spacer implantation is safe and well tolerated. Acute and chronic rectal toxicities are low despite aggressive dose escalation. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  13. Dose calculation and isodose curves determination in brachytherapy

    International Nuclear Information System (INIS)

    Maranhao, Frederico B.; Lima, Fernando R.A.; Khoury, Helen J.

    2000-01-01

    Brachytherapy is a form of cancer treatment in which small radioactive sources are placed inside of, or close to small tumors, in order to cause tissue necrosis and, consequently, to interrupt the tumor growth process. A very important aspect to the planning of this therapy is the calculation of dose distributions in the tumor and nearby tissues, to avoid the unnecessary irradiation of healthy tissue. The objective of this work is to develop a computer program that will permit treatment planning for brachytherapy at low dose rates, minimizing the possible errors introduced when such calculations are done manually. Results obtained showed good agreement with those from programs such as BRA, which is widely used in medical practice. (author)

  14. Postoperative high dose rate vaginal apex brachytherapy in stage I endometrial adenocarcinoma

    International Nuclear Information System (INIS)

    Turner, B.; Knisely, J.; Kacinski, B.; Roberts, K.; Peschel, R.; Gumbs, A.; Rutherford, T.; Edraki, B.; Schwartz, P.; Chambers, J.; Kohorn, E.; Wilson, L.

    1996-01-01

    Introduction: Patients with stage I endometrial adenocarcinoma have traditionally been treated with TAH/BSO and radiation. The reported incidence of local recurrence in surgically treated patients with Figo stage IA or IB endometrial adenocarcinoma is 4-10% at 2 years. Combined surgery and radiation has resulted in a reduction of recurrence to 2-6%. We report the presentation, local and distant control, salvage rate, survival and complications for patients undergoing high dose rate (HDR) vaginal apex brachytherapy following surgery. Methods: Between 1985 and 1994 a total of 302 patients with Figo stage I endometrial carcinoma were treated with HDR Ir-192 vaginal apex brachytherapy to a total dose of 21 Gy in 3 fractions at 0.5 cm from the vaginal mucosa. The pathologic stage by treatment group was IA: 31%, IB: 68%, and IC: 1%. The histologic grade of the patient's tumors was grade 1: 69%, 2: 27%, and 3: 4%. The median time from surgery to radiation was 33 days (range 14-66 days). The median follow-up for 300 patients with stage IA (91 patients), IB (205 patients), and IC (4 patients) was respectively 36, 34 and 40 months (2 patients lost to follow-up prior to 6 months). Results: Patients presented with vaginal bleeding (94%) or abnormal pap smear (6%) at a median age for stage IA and IB, of 55 and 64 years, respectively. The crude overall survival of the patient population at 2 years is 95%. Median overall time to failure is 19.5 months (range 10-36 months). The overall failure rate was 2.7% (8 patients), local failure only 1.0% (38% of failed group), distant failure only 0.3% (12% of failed group) and combined local/distant failure 1.3% (50% of failed group). The local failure rate for pathologic stage IA patients was 1.0% and no distant disease was observed. The local failure rate for pathologic stage IB patients was 3.4% 7/205 and distant failure was 2.4% 5/205. The majority of patients with recurrence had grade 2 histologic changes 5/8. The overall salvage rate

  15. Impact of point A asymmetry on local control and survival for low dose-rate (LDR) brachytherapy in cervical cancer.

    Science.gov (United States)

    Opfermann, Krisha J; Wahlquist, Amy; Watkins, John; Kohler, Matthew; Jenrette, Joseph

    2012-03-01

    To evaluate whether Point A asymmetry in low dose-rate (LDR) brachytherapy is associated with local control (LC), disease-free survival (DFS) and/or overall survival (OS). A retrospective analysis of disease control and survival outcomes was conducted for patients who underwent LDR brachytherapy for advanced cervical cancer. Institutional protocol entailed concurrent chemotherapy and whole pelvis radiotherapy (WPRT) over 5 weeks, followed by placement of Fletcher-Suit tandem and colpostat applicators at weeks 6 and 8. Objective Point A doses, 80-85 Gy, were accomplished by placement of Cesium-137 (Cs-137) sources. Cox proportional hazards regression models were used to assess associations between disease control and survival endpoints with variables of interest. The records of 50 patients with FIGO stage IB1-IVA cervical cancer undergoing LDR brachytherapy at our institution were identified. Thirty of these patients had asymmetry > 2.5%, and 11 patients had asymmetry > 5%. At a median survivor follow-up of 20.25 months, 15 patients had experienced disease failure (including 5 cervical/vaginal apex only failures and 2 failures encompassing the local site). Right/left dose asymmetry at Point A was associated with statistically significantly inferior LC (p = 0.035) and inferior DFS (p = 0.011) for patients with mean Point A dose of > 80 Gy. Insufficient evidence existed to conclude an association with OS. LDR brachytherapy may be associated with clinically significant dose asymmetry. The present study demonstrates that patients with Point A asymmetry have a higher risk of failure for DFS and LC.

  16. Implementation of three-dimensional planning in brachytherapy of high dose rate for gynecology therapies

    International Nuclear Information System (INIS)

    Sales, Camila Pessoa de

    2015-01-01

    This work aims to implement the three-dimensional (3D) planning for gynecological brachytherapy treatments. For this purpose, tests of acceptance and commissioning of brachytherapy equipment were performed to establish a quality and periodic assurance program. For this purpose, an important step was searching for a material to be used as a dummy source, since the applicators do not have any specific dummy. In addition, the validation of the use of applicators library was made for reconstruction in computed tomography (CT) and magnetic resonance imaging (MRI). In order to validate 3D planning, comparison of doses in dose assessment points used in bidimensional (2D) plans have been performed with volumetric doses to adjacent organs to the tumor. Finally, a protocol was established for 3D brachytherapy planning alternately using magnetic resonance image (MRI) and CT images, making evaluation of the dose in the tumor through the recording of MR and CT images. It was not possible to find a suitable material that could be used as dummy in MRI. However, the acquisition of the license's library for the applicators made possible the 3D planning based on MRI. No correlation was found between volumetric and specific doses analyzed, showing the importance of the implementation of 3D planning. The average ratio between D 2cc and ICRU Bladder dose was 1,74, 22% higher than the ratio found by others authors. For the rectum, D 2cc was less than dose point for 60% of fractions; the average difference was 12,5%. The average ratio between D 2cc and point dose rectum, 0,85, is equivalent to the value showed by Kim et al, 0,91. The D 2cc for sigmoid was 69% higher than point dose used, unless it was not possible compare this value, since the sigmoid point used in the 2D procedures is not used in others institutes. Relative dose in 2 cc of sigmoid was 57% of the prescription dose, the same value was found by in literature. This work enabled the implementation of a viable

  17. In vivo assessment of catheter positioning accuracy and prolonged irradiation time on liver tolerance dose after single-fraction 192Ir high-dose-rate brachytherapy

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    Kropf Siegfried

    2011-09-01

    Full Text Available Abstract Background To assess brachytherapy catheter positioning accuracy and to evaluate the effects of prolonged irradiation time on the tolerance dose of normal liver parenchyma following single-fraction irradiation with 192 Ir. Materials and methods Fifty patients with 76 malignant liver tumors treated by computed tomography (CT-guided high-dose-rate brachytherapy (HDR-BT were included in the study. The prescribed radiation dose was delivered by 1 - 11 catheters with exposure times in the range of 844 - 4432 seconds. Magnetic resonance imaging (MRI datasets for assessing irradiation effects on normal liver tissue, edema, and hepatocyte dysfunction, obtained 6 and 12 weeks after HDR-BT, were merged with 3D dosimetry data. The isodose of the treatment plan covering the same volume as the irradiation effect was taken as a surrogate for the liver tissue tolerance dose. Catheter positioning accuracy was assessed by calculating the shift between the 3D center coordinates of the irradiation effect volume and the tolerance dose volume for 38 irradiation effects in 30 patients induced by catheters implanted in nearly parallel arrangement. Effects of prolonged irradiation were assessed in areas where the irradiation effect volume and tolerance dose volume did not overlap (mismatch areas by using a catheter contribution index. This index was calculated for 48 irradiation effects induced by at least two catheters in 44 patients. Results Positioning accuracy of the brachytherapy catheters was 5-6 mm. The orthogonal and axial shifts between the center coordinates of the irradiation effect volume and the tolerance dose volume in relation to the direction vector of catheter implantation were highly correlated and in first approximation identically in the T1-w and T2-w MRI sequences (p = 0.003 and p p = 0.001 and p = 0.004, respectively. There was a significant shift of the irradiation effect towards the catheter entry site compared with the planned dose

  18. High dose rate versus medium dose rate intraluminal brachytherapy in inoperable esophageal carcinoma

    International Nuclear Information System (INIS)

    Langendijk, J.; Jager, J.; Jong, J. de; Rijken, J.; Pannebakker, M.

    1996-01-01

    Introduction: The purpose of this study was to compare the results of medium dose rate (MDR) intraluminal brachytherapy (ILBT) and high dose rate (HDR) ILBT in patients with inoperable esophageal carcinoma, with regard to dysphagia, complication rate and survival. Material and methods: Included were 114 patients with inoperable esophageal cancer who were treated with a single session of ILBT. In all cases a single dose of 15 Gy was administered, calculated at a 1 cm radius. Forty-eight patients were treated with MDR ( 137 Cs)ILBT. In June 1990 MDR was replaced by HDR and from then 66 patients were treated with HDR ( 192 Ir). Dysphagia was prospectively scored using a 5-point scale at 6 weeks, 3, 6, 9 and 12 months. Results: No significant differences were noted between the two groups with regard to pretreatment variables. In patients treated with MDR-ILBT improvement of swallowing ability was noted in 30 out of 42 evaluable patients (71%), no change in 9 (21%) and progression of dysphagia in 3 patients (8%), as compared to 34 out of 59 evaluable patients (58%), 16 (27%) and 6 (15%) resp. in de HDR-ILBT group. In the latter category, progression of dysphagia was caused by fistulae in 2 patients. The differences were not significant (ns). Additional treatment in case of recurrent or persistent dysphagia was needed in 50% of the cases in the MDR-ILBT group as compared to 41% in the HDR-ILBT group (ns). The median survival of the MDR-ILBT group was 3.9 months as compared to 4.3 months in the HDR-ILBT group (ns). In 2 patients (4%) treated with MDR-ILBT bronchio-oesphageal fistulae developed at 6 weeks and 2 months. In the HDR-ILBT group fistulae were noted in 7 cases (11%) at 2 weeks, 4 weeks, 2, 3, 3, 4 and 9 months (ns). In all of these cases persistent of recurrent tumour was present. Conclusions: No significant differences were noted with regard to palliation of dysphagia, survival and complication rate between MDR-ILBT and HDR-ILBT in the management of esophageal

  19. Novel use of ViewRay MRI guidance for high-dose-rate brachytherapy in the treatment of cervical cancer.

    Science.gov (United States)

    Ko, Huaising C; Huang, Jessie Y; Miller, Jessica R; Das, Rupak K; Wallace, Charles R; De Costa, Anna-Maria A; Francis, David M; Straub, Margaret R; Anderson, Bethany M; Bradley, Kristin A

    To characterize image quality and feasibility of using ViewRay MRI (VR)-guided brachytherapy planning for cervical cancer. Cervical cancer patients receiving intracavitary brachytherapy with tandem and ovoids, planned using 0.35T VR MRI at our institution, were included in this series. The high-risk clinical target volume (HR-CTV), visible gross tumor volume, bladder, sigmoid, bowel, and rectum contours for each fraction of brachytherapy were evaluated for dosimetric parameters. Typically, five brachytherapy treatments were planned using the T2 sequence on diagnostic MRI for the first and third fractions, and a noncontrast true fast imaging with steady-state precession sequence on VR or CT scan for the remaining fractions. Most patients received 5.5 Gy × 5 fractions using high-dose-rate Ir-192 following 45 Gy of whole-pelvis radiotherapy. The plan was initiated at 5.5 Gy to point A and subsequently optimized and prescribed to the HR-CTV. The goal equivalent dose in 2 Gy fractions for the combined external beam and brachytherapy dose was 85 Gy. Soft-tissue visualization using contrast-to-noise ratios to distinguish normal tissues from tumor at their interface was compared between diagnostic MRI, CT, and VR. One hundred and forty-two fractions of intracavitary brachytherapy were performed from April 2015 to January 2017 on 29 cervical cancer patients, ranging from stages IB1 to IVA. The median HR-CTV was 27.78 cc, with median D 90 HR-CTV of 6.1 Gy. The median time from instrument placement to start of treatment using VR was 65 min (scan time 2 min), compared to 105 min using diagnostic MRI (scan time 11 min) (t-test, p < 0.01). The contrast-to-noise ratio of tumor to cervix in both diagnostic MRI and VR had significantly higher values compared to CT (ANOVA and t-tests, p < 0.01). We report the first clinical use of VR-guided brachytherapy. Time to treatment using this approach was shorter compared to diagnostic MRI. VR also provided significant

  20. Medium-dose-rate brachytherapy of cancer of the cervix: preliminary results of a prospectively designed schedule based on the linear-quadratic model

    International Nuclear Information System (INIS)

    Leborgne, Felix; Fowler, Jack F.; Leborgne, Jose H.; Zubizarreta, Eduardo; Curochquin, Rene

    1999-01-01

    Purpose: To compare results and complications of our previous low-dose-rate (LDR) brachytherapy schedule for early-stage cancer of the cervix, with a prospectively designed medium-dose-rate (MDR) schedule, based on the linear-quadratic model (LQ). Methods and Materials: A combination of brachytherapy, external beam pelvic and parametrial irradiation was used in 102 consecutive Stage Ib-IIb LDR treated patients (1986-1990) and 42 equally staged MDR treated patients (1994-1996). The planned MDR schedule consisted of three insertions on three treatment days with six 8-Gy brachytherapy fractions to Point A, two on each treatment day with an interfraction interval of 6 hours, plus 18 Gy external whole pelvic dose, and followed by additional parametrial irradiation. The calculated biologically effective dose (BED) for tumor was 90 Gy 10 and for rectum below 125 Gy 3 . Results: In practice the MDR brachytherapy schedule achieved a tumor BED of 86 Gy 10 and a rectal BED of 101 Gy 3 . The latter was better than originally planned due to a reduction from 85% to 77% in the percentage of the mean dose to the rectum in relation to Point A. The mean overall treatment time was 10 days shorter for MDR in comparison with LDR. The 3-year actuarial central control for LDR and MDR was 97% and 98% (p = NS), respectively. The Grades 2 and 3 late complications (scale 0 to 3) were 1% and 2.4%, respectively for LDR (3-year) and MDR (2-year). Conclusions: LQ is a reliable tool for designing new schedules with altered fractionation and dose rates. The MDR schedule has proven to be an equivalent treatment schedule compared with LDR, with an additional advantage of having a shorter overall treatment time. The mean rectal BED Gy 3 was lower than expected

  1. Effect of edema, relative biological effectiveness, and dose heterogeneity on prostate brachytherapy

    International Nuclear Information System (INIS)

    Wang, Jian Z.; Mayr, Nina A.; Nag, Subir; Montebello, Joseph; Gupta, Nilendu; Samsami, Nina; Kanellitsas, Christos

    2006-01-01

    Many factors influence response in low-dose-rate (LDR) brachytherapy of prostate cancer. Among them, edema, relative biological effectiveness (RBE), and dose heterogeneity have not been fully modeled previously. In this work, the generalized linear-quadratic (LQ) model, extended to account for the effects of edema, RBE, and dose heterogeneity, was used to assess these factors and their combination effect. Published clinical data have shown that prostate edema after seed implant has a magnitude (ratio of post- to preimplant volume) of 1.3-2.0 and resolves exponentially with a half-life of 4-25 days over the duration of the implant dose delivery. Based on these parameters and a representative dose-volume histogram (DVH), we investigated the influence of edema on the implant dose distribution. The LQ parameters (α=0.15 Gy -1 and α/β=3.1 Gy) determined in earlier studies were used to calculate the equivalent uniform dose in 2 Gy fractions (EUD 2 ) with respect to three effects: edema, RBE, and dose heterogeneity for 125 I and 103 Pd implants. The EUD 2 analysis shows a negative effect of edema and dose heterogeneity on tumor cell killing because the prostate edema degrades the dose coverage to tumor target. For the representative DVH, the V 100 (volume covered by 100% of prescription dose) decreases from 93% to 91% and 86%, and the D 90 (dose covering 90% of target volume) decrease from 107% to 102% and 94% of prescription dose for 125 I and 103 Pd implants, respectively. Conversely, the RBE effect of LDR brachytherapy [versus external-beam radiotherapy (EBRT) and high-dose-rate (HDR) brachytherapy] enhances dose effect on tumor cell kill. In order to balance the negative effects of edema and dose heterogeneity, the RBE of prostate brachytherapy was determined to be approximately 1.2-1.4 for 125 I and 1.3-1.6 for 103 Pd implants. These RBE values are consistent with the RBE data published in the literature. These results may explain why in earlier modeling studies

  2. Biological effective doses in the intracavitary high dose rate brachytherapy of cervical cancer

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    Y. Sobita Devi

    2011-12-01

    Full Text Available Purpose: The aim of this study is to evaluate the decrease of biological equivalent dose and its correlation withlocal/loco-regional control of tumour in the treatment of cervical cancer when the strength of the Ir-192 high dose rate(HDR brachytherapy (BT source is reduced to single, double and triple half life in relation to original strength of10 Ci (~ 4.081 cGy x m2 x h–1. Material and methods: A retrospective study was carried out on 52 cervical cancer patients with stage II and IIItreated with fractionated HDR-BT following external beam radiation therapy (EBRT. International Commission onRadiation Units and Measurement (ICRU points were defined according to ICRU Report 38, using two orthogonal radiographimages taken by Simulator (Simulix HQ. Biologically effective dose (BED was calculated at point A for diffe -rent Ir-192 source strength and its possible correlation with local/loco-regional tumour control was discussed. Result: The increase of treatment time per fraction of dose due to the fall of dose rate especially in HDR-BT of cervicalcancer results in reduction in BED of 2.59%, 7.02% and 13.68% with single, double and triple half life reduction ofsource strength, respectively. The probabilities of disease recurrence (local/loco-regional within 26 months are expectedas 0.12, 0.12, 0.16, 0.39 and 0.80 for source strength of 4.081, 2.041, 1.020, 0.510 and 0.347 cGy x m2 x h–1, respectively.The percentages of dose increase required to maintain the same BED with respect to initial BED were estimated as1.71, 5.00, 11.00 and 15.86 for the dose rate of 24.7, 12.4, 6.2 and 4.2 Gy/hr at point A, respectively. Conclusions: This retrospective study of cervical cancer patients treated with HDR-BT at different Ir-192 sourcestrength shows reduction in disease free survival according to the increase in treatment time duration per fraction.The probable result could be associated with the decrease of biological equivalent dose to point A. Clinical

  3. Breast-Conservative Surgery With Close or Positive Margins: Can the Breast Be Preserved With High-Dose-Rate Brachytherapy Boost?

    International Nuclear Information System (INIS)

    Guinot, Jose Luis; Roldan, Susana; Maronas, Maria; Tortajada, Isabel; Carrascosa, Maria; Chust, Maria Luisa; Estornell, Marian; Mengual, Jose Luis; Arribas, Leoncio

    2007-01-01

    Purpose: To evaluate the likelihood of preserving the breast in women who show close or positive margins after conservative surgery for early breast carcinoma. Methods and Materials: Since 1996, 125 women with less than 5 mm or positive margins and positive separate cavity margin sampling were entered in a prospective trial with high-dose radiotherapy. A standard dose of 50 Gy to the whole breast was followed by a high-dose-rate brachytherapy application delivering 3 fractions of 4.4 Gy in 24 hours. The median follow-up was 84 months. Results: There were only seven local recurrences, with an actuarial local control rate of 95.8% at 5 years and 91.1% at 9 years. Actuarial overall and cause-specific survival rates were 92.6% and 95% at 5 years and 86.7% and 90.4% at 9 years, respectively. Late fibrosis was the most common complication, in 30% of patients, with good or excellent cosmetic results in 77%. The final result was that 95.2% of breasts were preserved. Conclusions: Close or positive-margin breast cancer can be well managed with a high-dose boost in a wide tumor bed by means of high-dose-rate brachytherapy. This technique can avoid mastectomy or poor cosmetic resection, with minimal risk of local or general failure

  4. Volume correction factor in time dose relationships in brachytherapy

    International Nuclear Information System (INIS)

    Supe, S.J.; Sasane, J.B.

    1987-01-01

    Paterson's clinical data about the maximum tolerance doses for various volumes of interstitial implants with Ra-226 delivered in seven days was made use of in deriving volume correction factors for TDF and CRE concepts respectively for brachytherapy. The derived volume correction factors for TDF and for CRE differ fromthe one assumed for CRE by Kirk et al. and implied for TDF by Goitein. A normalising volume of 70 cc has been suggested for both CRE and TDF concepts for brachytherapy. A table showing the volume corrected TDF is presented for various volumes and dose rates for continuous irradiation. The use of this table is illustrated with examples. (orig.) [de

  5. Computed tomography-based treatment planning for high-dose-rate brachytherapy using the tandem and ring applicator: influence of applicator choice on organ dose and inter-fraction adaptive planning

    Directory of Open Access Journals (Sweden)

    Vishruta A. Dumane

    2017-06-01

    Full Text Available Three dimensional planning for high-dose-rate (HDR brachytherapy in cervical cancer has been highly recommended by consensus guidelines such as the American Brachytherapy Society (ABS and the Groupe Européen de Curiethérapie – European Society for Radiotherapy and Oncology (GEC-ESTRO. In this document, we describe our experience with computed tomography (CT-based planning using the tandem/ring applicator. We discuss the influence of applicator geometry on doses to organs at risk (OARs, namely the bladder, rectum, and sigmoid. Through example cases with dose prescribed to point A, we demonstrate how adaptive planning can help achieve constraints to the OARs as per guidelines.

  6. Surface applicators for high dose rate brachytherapy in AIDS-related kaposi's sarcoma

    International Nuclear Information System (INIS)

    Evans, Michael D.C.; Yassa, Mariam; Podgorsak, Ervin B.; Roman, Ted N.; Schreiner, L. John; Souhami, Luis

    1997-01-01

    Purpose: The development of commercially available surface applicators using high dose rate remote afterloading devices has enabled radiotherapy centers to treat selected superficial lesions using a remote afterloading brachytherapy unit. The dosimetric parameters of these applicators, the clinical implementation of this technique, and a review of the initial patient treatment regimes are presented. Methods and Materials: A set of six fixed-diameter (1, 2, and 3 cm), tungsten/steel surface applicators is available for use with a single stepping-source (Ir-192, 370 GBq) high dose rate afterloader. The source can be positioned either in a parallel or perpendicular orientation to the treatment plane at the center of a conical aperture that sits at an SSD of approximately 15 mm and is used with a 1-mm thick removable plastic cap. The surface dose rates, percent depth dose, and off-axis ratios were measured. A custom-built, ceiling-mounted immobilization device secures the applicator on the surface of the patient's lesion during treatment. Results: Between November 1994, and September 1996, 16 AIDS-related Kaposi's sarcoma patients having a total of 120 lesions have been treated with palliative intent. Treatment sites were distributed between the head and neck, extremity, and torso. Doses ranged from 8 to 20 Gy, with a median dose of 10 Gy delivered in a single fraction. Treatments were well tolerated with minimal skin reaction, except for patients with lesions treated to 20 Gy who developed moderate/severe desquamation. Conclusion: Radiotherapy centers equipped with a high dose rate remote afterloading unit may treat small selected surface lesions with commercially available surface applicators. These surface applicators must be used with a protective cap to eliminate electron contamination. The optimal surface dose appears to be either 10 or 15 Gy depending upon the height of the lesion

  7. Dose optimization of intra-operative high dose rate interstitial brachytherapy implants for soft tissue sarcoma

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    Jamema Swamidas

    2009-01-01

    Full Text Available Objective : A three dimensional (3D image-based dosimetric study to quantitatively compare geometric vs. dose-point optimization in combination with graphical optimization for interstitial brachytherapy of soft tissue sarcoma (STS. Materials and Methods : Fifteen consecutive STS patients, treated with intra-operative, interstitial Brachytherapy, were enrolled in this dosimetric study. Treatment plans were generated using dose points situated at the "central plane between the catheters", "between the catheters throughout the implanted volume", at "distances perpendicular to the implant axis" and "on the surface of the target volume" Geometrically optimized plans had dose points defined between the catheters, while dose-point optimized plans had dose points defined at a plane perpendicular to the implant axis and on the target surface. Each plan was graphically optimized and compared using dose volume indices. Results : Target coverage was suboptimal with coverage index (CI = 0.67 when dose points were defined at the central plane while it was superior when the dose points were defined at the target surface (CI=0.93. The coverage of graphically optimized plans (GrO was similar to non-GrO with dose points defined on surface or perpendicular to the implant axis. A similar pattern was noticed with conformity index (0.61 vs. 0.82. GrO were more conformal and less homogeneous compared to non-GrO. Sum index was superior for dose points defined on the surface of the target and relatively inferior for plans with dose points at other locations (1.35 vs. 1.27. Conclusions : Optimization with dose points defined away from the implant plane and on target results in superior target coverage with optimal values of other indices. GrO offer better target coverage for implants with non-uniform geometry and target volume.

  8. Dosimetric perturbations of a lead shield for surface and interstitial high-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Candela-Juan, Cristian; Granero, Domingo; Vijande, Javier; Ballester, Facundo; Perez-Calatayud, Jose; Rivard, Mark J

    2014-01-01

    In surface and interstitial high-dose-rate brachytherapy with either 60 Co, 192 Ir, or 169 Yb sources, some radiosensitive organs near the surface may be exposed to high absorbed doses. This may be reduced by covering the implants with a lead shield on the body surface, which results in dosimetric perturbations. Monte Carlo simulations in Geant4 were performed for the three radionuclides placed at a single dwell position. Four different shield thicknesses (0, 3, 6, and 10 mm) and three different source depths (0, 5, and 10 mm) in water were considered, with the lead shield placed at the phantom surface. Backscatter dose enhancement and transmission data were obtained for the lead shields. Results were corrected to account for a realistic clinical case with multiple dwell positions. The range of the high backscatter dose enhancement in water is 3 mm for 60 Co and 1 mm for both 192 Ir and 169 Yb. Transmission data for 60 Co and 192 Ir are smaller than those reported by Papagiannis et al (2008 Med. Phys. 35 4898–4906) for brachytherapy facility shielding; for 169 Yb, the difference is negligible. In conclusion, the backscatter overdose produced by the lead shield can be avoided by just adding a few millimetres of bolus. Transmission data provided in this work as a function of lead thickness can be used to estimate healthy organ equivalent dose saving. Use of a lead shield is justified. (paper)

  9. The status of low dose rate and future of high dose rate Cf-252 brachytherapy

    International Nuclear Information System (INIS)

    Rivard, M.J.; Wierzbicki, J.G.; Van den Heuvel, F.; Chuba, P.J.; Fontanesi, J.

    1997-12-01

    This work describes the current status of the US low dose rate (LDR) Cf-252 brachytherapy program. The efforts undertaken towards development of a high dose rate (HDR) remotely after loaded Cf-252 source, which can accommodate 1 mg or greater Cf-252, are also described. This HDR effort is a collaboration between Oak Ridge National Laboratory (ORNL), commercial remote after loader manufactures, the Gershenson Radiation Oncology Center (ROC), and Wayne State University. To achieve this goal, several advances in isotope chemistry and source preparation at ORNL must be achieved to yield a specific material source loading of greater than or equal 1 mg Cf-252 per mm3. Development work with both radioactive and non-radioactive stand-ins for Cf-252 have indicated the feasibility of fabricating such sources. As a result, the decreased catheter diameter and computer controlled source placement will permit additional sites (e.g. brain, breast, prostate, lung, parotid, etc.) to be treated effectively with Cf-252 sources. Additional work at the Radiochemical Engineering and Development Center (REDC) remains in source fabrication, after loader modification, and safe design. The current LDR Cf-252 Treatment Suite at the ROC is shielded and licensed to hold up to 1 mg of Cf-252. This was designed to maintain cumulative personnel exposure, both external to the room and in direct isotope handling, at less than 20 microSv/hr. However, cumulative exposure may be greatly decreased if a Cf-252 HDR unit is employed which would eliminate direct isotope handling and decrease treatment times from tilde 3 hours to an expected range of 3 to 15 minutes. Such a Cf-252 HDR source will also demonstrate improved dose distributions over current LDR treatments due to the ability to step the point-like source throughout the target volume and weight the dwell time accordingly

  10. Calibration of {sup 192}Ir high dose rate brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Marechal, M H [Instituto de Radioprotecao e Dozimetria, Rio de Jainero (Brazil); Almeida, C.E. de [Laboratorio de Ciencias Radiologicas, UERL, Rio de Janeiro (Brazil); Sibata, C H [Roswell Park Cancer Inst., Buffalo, NY (United States)

    1996-08-01

    A method for calibration of high dose rate sources used in afterloading brachytherapy systems is described. The calibration for {sup 192}Ir is determined by interpolating {sup 60}Co gamma-rays and 250 kV x-rays calibration factors. All measurements were done using the same build up caps as described by Goetsch et al and recommended by AAPM. The attenuation correction factors were determined to be 0.9903, 0.9928 and 0.9993 for {sup 192}Ir, {sup 60}Co and 250 kV x-ray, respectively. A wall + cap thickness of 0.421 g.cm{sup -2} is recommended for all measurements to ensure electronic equilibrium for {sup 60}Co and {sup 192}Ir gamma-ray beams. A mathematical formalism is described for determination of (N{sub x}){sub Ir}. (author). 5 refs, 1 fig.

  11. Rectal Bleeding After High-Dose-Rate Brachytherapy Combined With Hypofractionated External-Beam Radiotherapy for Localized Prostate Cancer: The Relationship Between Dose-Volume Histogram Parameters and the Occurrence Rate

    International Nuclear Information System (INIS)

    Okamoto, Masahiko; Ishikawa, Hitoshi; Ebara, Takeshi; Kato, Hiroyuki; Tamaki, Tomoaki; Akimoto, Tetsuo; Ito, Kazuto; Miyakubo, Mai; Yamamoto, Takumi; Suzuki, Kazuhiro; Takahashi, Takeo; Nakano, Takashi

    2012-01-01

    Purpose: To determine the predictive risk factors for Grade 2 or worse rectal bleeding after high-dose-rate brachytherapy (HDR-BT) combined with hypofractionated external-beam radiotherapy (EBRT) for prostate cancer using dose–volume histogram analysis. Methods and Materials: The records of 216 patients treated with HDR-BT combined with EBRT were analyzed. The treatment protocols for HDR-BT were 5 Gy × five times in 3 days or 7 Gy × three, 10.5 Gy × two, or 9 Gy × two in 2 days. The EBRT doses ranged from 45 to 51 Gy with a fractional dose of 3 Gy. Results: In 20 patients Grade 2 or worse rectal bleeding developed, and the cumulative incidence rate was 9% at 5 years. By converting the HDR-BT and EBRT radiation doses into biologic effective doses (BED), the BED 3 at rectal volumes of 5% and 10% in the patients who experienced bleeding were significantly higher than those in the remaining 196 patients. Univariate analysis showed that a higher rectal BED 3–5% and the use of fewer needles in brachytherapy were correlated with the incidence of bleeding, but BED 3–5% was found to be the only significant factor on multivariate analysis. Conclusions: The radiation dose delivered to small rectal lesions as 5% is important for predicting Grade 2 or worse rectal bleeding after HDR-BT combined with EBRT for prostate cancer.

  12. Photon spectrometry for the determination of the dose-rate constant of low-energy photon-emitting brachytherapy sources

    International Nuclear Information System (INIS)

    Chen, Zhe Jay; Nath, Ravinder

    2007-01-01

    Accurate determination of dose-rate constant (Λ) for interstitial brachytherapy sources emitting low-energy photons (<50 keV) has remained a challenge in radiation dosimetry because of the lack of a suitable absolute dosimeter for accurate measurement of the dose rates near these sources. Indeed, a consensus value of Λ taken as the arithmetic mean of the dose-rate constants determined by different research groups and dosimetry techniques has to be used at present for each source model in order to minimize the uncertainties associated with individual determinations of Λ. Because the dosimetric properties of a source are fundamentally determined by the characteristics of the photons emitted by the source, a new technique based on photon spectrometry was developed in this work for the determination of dose-rate constant. The photon spectrometry technique utilized a high-resolution gamma-ray spectrometer to measure source-specific photon characteristics emitted by the low-energy sources and determine their dose-rate constants based on the measured photon-energy spectra and known dose-deposition properties of mono-energetic photons in water. This technique eliminates many of the difficulties arising from detector size, the energy dependence of detector sensitivity, and the use of non-water-equivalent solid phantoms in absolute dose rate measurements. It also circumvents the uncertainties that might be associated with the source modeling in Monte Carlo simulation techniques. It was shown that the estimated overall uncertainty of the photon spectrometry technique was less than 4%, which is significantly smaller than the reported 8-10% uncertainty associated with the current thermo-luminescent dosimetry technique. In addition, the photon spectrometry technique was found to be stable and quick in Λ determination after initial setup and calibration. A dose-rate constant can be determined in less than two hours for each source. These features make it ideal to determine

  13. Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the VSL and the BIPM

    DEFF Research Database (Denmark)

    Alvarez, J.T.; De Pooter, J.A.; Andersen, Claus E.

    2014-01-01

    An indirect comparison of the standards for reference air kerma rate for 192Ir high dose rate brachytherapy sources of the Dutch Metrology Institute (VSL), The Netherlands, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the VSL in November 2009. The comparison resu...

  14. Demonstration of brachytherapy boost dose-response relationships in glioblastoma multiforme

    International Nuclear Information System (INIS)

    Sneed, Penny K.; Lamborn, Kathleen R.; Larson, David A.; Prados, Michael D.; Malec, Mary K.; McDermott, Michael W.; Weaver, Keith A.; Phillips, Theodore L.; Wara, William M.; Gutin, Philip H.

    1996-01-01

    Purpose: To evaluate brachytherapy dose-response relationships in adults with glioblastoma undergoing temporary 125 I implant boost after external beam radiotherapy. Methods and Materials: Since June 1987, orthogonal radiographs using a fiducial marker box have been used to verify brain implant source positions and generate dose-volume histograms at the University of California, San Francisco. For adults who underwent brachytherapy boost for glioblastoma from June 1987 through December 1992, tumor volumes were reoutlined to ensure consistency and dose-volume histograms were recalculated. Univariate and multivariate analyses of various patient and treatment parameters were performed evaluating for influence of dose on freedom from local failure (FFLF) and actuarial survival. Results: Of 102 implant boosts, 5 were excluded because computer plans were unavailable. For the remaining 97 patients, analyses with adjustment for known prognostic factors (age, KPS, extent of initial surgical resection) and prognostic factors identified on univariate testing (adjuvant chemotherapy) showed that higher minimum brachytherapy tumor dose was strongly associated with improved FFLF (p = 0.001). A quadratic relationship was found between total biological effective dose and survival, with a trend toward optimal survival probability at 47 Gy minimum brachytherapy tumor dose (corresponding to about 65 Gy to 95% of the tumor volume); survival decreased with lower or higher doses. Two patients expired and one requires hospice care because of brain necrosis after brachytherapy doses > 63 Gy to 95% of the tumor volume with 60 Gy to > 18 cm 3 of normal brain. Conclusion: Although higher minimum brachytherapy tumor dose was strongly associated with better local control, a brachytherapy boost dose > 50-60 Gy may result in life-threatening necrosis. We recommend careful conformation of the prescription isodose line to the contrast enhancing tumor volume, delivery of a minimum brachytherapy

  15. Radioablation of adrenal gland malignomas with interstitial high-dose-rate brachytherapy. Efficacy and outcome

    Energy Technology Data Exchange (ETDEWEB)

    Mohnike, K. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Magdeburg (Germany); DTZ am Frankfurter Tor, Berlin (Germany); Neumann, K.; Seidensticker, M.; Seidensticker, R.; Pech, M.; Streitparth, T.; Ricke, J. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Magdeburg (Germany); Hass, P.; Gademann, G. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Strahlentherapie, Magdeburg (Germany); Klose, S. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Nieren- und Hochdruckkrankheiten, Diabetologie und Endokrinologie, Magdeburg (Germany); Garlipp, B.; Benckert, C. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Allgemein-, Viszeral- und Gefaesschirurgie, Magdeburg (Germany); Wendler, J.J.; Liehr, U.B.; Schostak, M. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Urologie und Kinderurologie, Magdeburg (Germany); Goeppner, D. [Universitaetsklinikum Magdeburg A.oe.R., Otto-von-Guericke-Universitaet, Klinik fuer Dermatologie, Magdeburg (Germany)

    2017-08-15

    To assess the efficacy, safety, and outcome of image-guided high-dose-rate (HDR) brachytherapy in patients with adrenal gland metastases (AGM). From January 2007 to April 2014, 37 patients (7 female, 30 male; mean age 66.8 years, range 41.5-82.5 years) with AGM from different primary tumors were treated with CT-guided HDR interstitial brachytherapy (iBT). Primary endpoint was local tumor control (LTC). Secondary endpoints were time to untreatable progression (TTUP), time to progression (TTP), overall survival (OS), and safety. In a secondary analysis, risk factors with an influence on survival were identified. The median biological equivalent dose (BED) was 37.4 Gy. Mean LTC after 12 months was 88%; after 24 months this was 74%. According to CTCAE criteria, one grade 3 adverse event occurred. Median OS after first diagnosis of AGM was 18.3 months. Median OS, TTUP, and TTP after iBT treatment were 11.4, 6.6, and 3.5 months, respectively. Uni- and multivariate Cox regression analyses revealed significant influences of synchronous disease, tumor diameter, and the total number of lesions on OS or TTUP or both. Image-guided HDR-iBT is safe and effective. Treatment- and primary tumor-independent features influenced survival of patients with AGM after HDR-iBR treatment. (orig.) [German] Beurteilung der Effektivitaet, Sicherheit und Ergebnisse nach bildgefuehrter High-dose-rate-(HDR-)Brachytherapie bei Patienten mit Nebennierenmetastasen. Von Januar 2007 bis April 2014 wurden 37 Patienten (7 weiblich, 30 maennlich; mittleres Alter 66,8 Jahre, Spanne 41,5-82,5 Jahre) mit Nebennierenmetastasen verschiedener Primarien mit CT-gesteuerter interstitieller HDR-Brachytherapie (iBT) behandelt. Der primaere Endpunkt war die lokale Tumorkontrolle (LTC). Sekundaere Endpunkte umfassten die Zeit bis zum nicht mehr behandelbaren Progress (TTUP), die Zeit bis zum Progress (TTP), das Gesamtueberleben (OS) und die Sicherheit der Methode. In einer sekundaeren Analyse wurden Risikofaktoren

  16. Genitourinary Toxicity After High-Dose-Rate (HDR) Brachytherapy Combined With Hypofractionated External Beam Radiotherapy for Localized Prostate Cancer: An Analysis to Determine the Correlation Between Dose-Volume Histogram Parameters in HDR Brachytherapy and Severity of Toxicity

    International Nuclear Information System (INIS)

    Ishiyama, Hiromichi; Kitano, Masashi; Satoh, Takefumi; Kotani, Shouko; Uemae, Mineko; Matsumoto, Kazumasa; Okusa, Hiroshi; Tabata, Ken-ichi; Baba, Shiro; Hayakawa, Kazushige

    2009-01-01

    Purpose: To evaluate the severity of genitourinary (GU) toxicity in high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiotherapy (EBRT) for prostate cancer and to explore factors that might affect the severity of GU toxicity. Methods and Materials: A total of 100 Japanese men with prostate cancer underwent 192 Ir HDR brachytherapy combined with hypofractionated EBRT. Mean (SD) dose to 90% of the planning target volume was 6.3 (0.7) Gy per fraction of HDR. After 5 fractions of HDR treatment, EBRT with 10 fractions of 3 Gy was administrated. The urethral volume receiving 1-15 Gy per fraction in HDR brachytherapy (V1-V15) and the dose to at least 5-100% of urethral volume in HDR brachytherapy (D5-D100) were compared between patients with Grade 3 toxicity and those with Grade 0-2 toxicity. Prostate volume, patient age, and International Prostate Symptom Score were also compared between the two groups. Results: Of the 100 patients, 6 displayed Grade 3 acute GU toxicity, and 12 displayed Grade 3 late GU toxicity. Regarding acute GU toxicity, values of V1, V2, V3, and V4 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Regarding late GU toxicity, values of D70, D80, V12, and V13 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Conclusions: The severity of GU toxicity in HDR brachytherapy combined with hypofractionated EBRT for prostate cancer was relatively high. The volume of prostatic urethra was associated with grade of acute GU toxicity, and urethral dose was associated with grade of late GU toxicity.

  17. Three dimensional implementation of anisotropy corrected fast fourier transform dose calculation around brachytherapy seeds

    International Nuclear Information System (INIS)

    Kyeremeh, P.O.

    2011-01-01

    Current-available brachytherapy dose computation algorithms ignore heterogeneities such as tissue-air interfaces, shielded gynaecological colpostats, and tissue-composition variations in source implants despite dose computation errors as large as 40%. A convolution kernel, which takes into consideration anisotropy of the dose distribution around a brachytherapy source, and to compute dose in the presence of tissue and applicator heterogeneities, has been established. Resulting from the convolution kernel are functions with polynomial and exponential terms. the solution to the convolution integral was represented by the Fast Fourier transform. The Fast Fourier transform has shown enough potency in accounting for errors due to these heterogeneities and the versatility of this Fast Fourier transform is evident from its capability of switching in between fields. Thus successful procedures in external beam could be adopted in brachytherapy to a yield similar effect. A dose deposition kernel was developed for a 64x64x64 matrix size with wrap around ordering and convoluted with the distribution of the sources in 3D. With MatLab's inverse Fast Fourier transform, dose rate distribution for a given array of interstitial sources, typical of brachytherapy was calculated. The shape of the dose rate distribution peaks appeared comparable with the output expected from computerized treatment planning systems for brachytherapy. Subsequently, the study confirmed the speed and accuracy of dose computation using the FFT convolution as well juxtaposed. Although, dose rate peaks from both the FFT convolution and the TPS(TG43) did not compare quantitatively, which was mainly due to the TPS(TG43) initiation computations from the origin (0,0,0) unlike the FFT convolution which uses sampling points; N=1,2,3..., there is a strong basis for establishing parity since the dose rate peaks compared qualitatively. With both modes compared, the discrepancies in the dose rates ranged between 3.6% to

  18. Brachytherapy Application With In Situ Dose Painting Administered by Gold Nanoparticle Eluters

    International Nuclear Information System (INIS)

    Sinha, Neeharika; Cifter, Gizem; Sajo, Erno; Kumar, Rajiv; Sridhar, Srinivas; Nguyen, Paul L.; Cormack, Robert A.; Makrigiorgos, G. Mike; Ngwa, Wilfred

    2015-01-01

    Purpose: Recent studies show promise that administering gold nanoparticles (GNP) to tumor cells during brachytherapy could significantly enhance radiation damage to the tumor. A new strategy proposed for sustained administration of the GNP in prostate tumors is to load them into routinely used brachytherapy spacers for customizable in situ release after implantation. This in silico study investigated the intratumor biodistribution and corresponding dose enhancement over time due to GNP released from such GNP-loaded brachytherapy spacers (GBS). Method and Materials: An experimentally determined intratumoral diffusion coefficient (D) for 10-nm nanoparticles was used to estimate D for other sizes by using the Stokes-Einstein equation. GNP concentration profiles, obtained using D, were then used to calculate the corresponding dose enhancement factor (DEF) for each tumor voxel, using dose painting-by-numbers approach, for times relevant to the considered brachytherapy sources' lifetimes. The investigation was carried out as a function of GNP size for the clinically applicable low-dose-rate brachytherapy sources iodine-125 (I-125), palladium-103 (Pd-103), and cesium-131 (Cs-131). Results: Results showed that dose enhancement to tumor voxels and subvolumes during brachytherapy can be customized by varying the size of GNP released or eluted from the GBS. For example, using a concentration of 7 mg/g GNP, significant DEF (>20%) could be achieved 5 mm from a GBS after 5, 12, 25, 46, 72, 120, and 195 days, respectively, for GNP sizes of 2, 5, 10, 20, 30, and 50 nm and for 80 nm when treating with I-125. Conclusions: Analyses showed that using Cs-131 provides the highest dose enhancement to tumor voxels. However, given its relatively longer half-life, I-125 presents the most flexibility for customizing the dose enhancement as a function of GNP size. These findings provide a useful reference for further work toward development of potential new brachytherapy application

  19. Brachytherapy Application With In Situ Dose Painting Administered by Gold Nanoparticle Eluters

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Neeharika [Department of Sciences, Wentworth Institute of Technology, Boston, Massachusetts (United States); Cifter, Gizem [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Sajo, Erno [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Kumar, Rajiv; Sridhar, Srinivas [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Electronic Materials Research Institute and Department of Physics, Northeastern University, Boston, Massachusetts (United States); Nguyen, Paul L.; Cormack, Robert A.; Makrigiorgos, G. Mike [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States); Ngwa, Wilfred, E-mail: wngwa@lroc.harvard.edu [Department of Physics and Applied Physics, University of Massachusetts, Lowell, Massachusetts (United States); Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (United States)

    2015-02-01

    Purpose: Recent studies show promise that administering gold nanoparticles (GNP) to tumor cells during brachytherapy could significantly enhance radiation damage to the tumor. A new strategy proposed for sustained administration of the GNP in prostate tumors is to load them into routinely used brachytherapy spacers for customizable in situ release after implantation. This in silico study investigated the intratumor biodistribution and corresponding dose enhancement over time due to GNP released from such GNP-loaded brachytherapy spacers (GBS). Method and Materials: An experimentally determined intratumoral diffusion coefficient (D) for 10-nm nanoparticles was used to estimate D for other sizes by using the Stokes-Einstein equation. GNP concentration profiles, obtained using D, were then used to calculate the corresponding dose enhancement factor (DEF) for each tumor voxel, using dose painting-by-numbers approach, for times relevant to the considered brachytherapy sources' lifetimes. The investigation was carried out as a function of GNP size for the clinically applicable low-dose-rate brachytherapy sources iodine-125 (I-125), palladium-103 (Pd-103), and cesium-131 (Cs-131). Results: Results showed that dose enhancement to tumor voxels and subvolumes during brachytherapy can be customized by varying the size of GNP released or eluted from the GBS. For example, using a concentration of 7 mg/g GNP, significant DEF (>20%) could be achieved 5 mm from a GBS after 5, 12, 25, 46, 72, 120, and 195 days, respectively, for GNP sizes of 2, 5, 10, 20, 30, and 50 nm and for 80 nm when treating with I-125. Conclusions: Analyses showed that using Cs-131 provides the highest dose enhancement to tumor voxels. However, given its relatively longer half-life, I-125 presents the most flexibility for customizing the dose enhancement as a function of GNP size. These findings provide a useful reference for further work toward development of potential new brachytherapy application

  20. Dose rate constants for 125I, 103Pd, 192Ir and 169Yb brachytherapy sources: an EGS4 Monte Carlo study

    International Nuclear Information System (INIS)

    Mainegra, Ernesto; Capote, Roberto; Lopez, Ernesto

    1998-01-01

    An exhaustive revision of dosimetry data for 192 Ir, 125 I, 103 Pd and 169 Yb brachytherapy sources has been performed by means of the EGS4 simulation system. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. The absorbed dose rate per unit contained activity in a medium at 1 cm in water and air-kerma strength per unit contained activity for each seed model were calculated, allowing the dose rate constant (DRC) Λ to be estimated. The influence of the calibration procedure on source strength for low-energy brachytherapy seeds is discussed. Conversion factors for 125 I and 103 Pd seeds to obtain the dose rate in liquid water from the dose rate measured in a solid water phantom with a detector calibrated for dose to water were calculated. A theoretical estimate of the DRC for a 103 Pd model 200 seed equal to 0.669±0.002 cGy h -1 U -1 is obtained. Comparison of obtained DRCs with measured and calculated published results shows agreement within 1.5% for 192 Ir, 169 Yb and 125 I sources. (author)

  1. Inverse planning in brachytherapy from radium to high rate 192 iridium afterloading

    International Nuclear Information System (INIS)

    Lahanas, M.; Mould, R.F.; Baltas, D.; Karauzakis, K.; Giannouli, S.; Baltas, D.

    2004-01-01

    We consider the inverse planning problem in brachytherapy, i.e. the problem to determine an optimal number of catheters, number of sources for low-dose rate brachytherapy (LDR) and the optimal dwell times for high-dose rate brachytherapy (HDR) necessary to obtain an optimal as possible dose distribution. Starting from the 1930s, inverse planning for LDR brachytherapy used geometrically derived rules to determine the optimal placement of sources in order to achieve a uniform dose distribution of a specific level in planes, spheres and cylinders. Rules and nomograms were derived which still are widely used. With the rapid development of 3D imaging technologies and the rapidly increasing computer power we have now entered the new era of computer-based inverse planning in brachytherapy. The inverse planning is now an optimisation process adapted to the individual geometry of the patient. New inverse planning optimisation algorithms are anatomy-based that consider the real anatomy of the tumour and the organs at risk (OAR). Computer-based inverse planning considers various effects such as stability of solutions for seed misplacements which cannot ever be solved analytically without gross simplifications. In the last few years multiobjective (MO) inverse planning algorithms have been developed which recognise the MO optimisation problem which is inherent in inverse planning in brachytherapy. Previous methods used a trial and error method to obtain a satisfactory solution. MO optimisation replaces this trial and error process by presenting a representative set of dose distributions that can be obtained. With MO optimisation it is possible to obtain information that can be used to obtain the optimum number of catheters, their position and the optimum distribution of dwell times for HDR brachytherapy. For LDR brachytherapy also the stability of solutions due to seed migration can also be improved. A spectrum of alternative solutions is available and the treatment planner

  2. High-dose rate brachytherapy in the treatment of carcinoma of uterine cervix: twenty-year experience with cobalt after-loading system.

    Science.gov (United States)

    Mosalaei, A; Mohammadianpanah, M; Omidvari, S; Ahmadloo, N

    2006-01-01

    This retrospective analysis aims to report results of patients with cancer of uterine cervix treated with external-beam radiotherapy (EBR) and high-dose rate (HDR) brachytherapy, using manual treatment planning. From 1975 to 1995, 237 patients with FIGO stages IIB-IVA and mean age of 54.31 years were treated. EBR dose to the whole pelvis was 50 Gy in 25 fractions. Brachytherapy with HDR after-loading cobalt source (Cathetron) was performed following EBR completion with a dose of 30 Gy in three weekly fractions of 10 Gy to point A. Survival, local control, and genitourinary and gastrointestinal complications were assessed. In a median follow-up of 60.2 months, the 10-year overall and disease-free survival rate was 62.4%. Local recurrence was seen in 12.2% of patients. Distant metastases to the lymph nodes, peritoneum, lung, liver, and bone occurred in 25.3% of patients. Less than 6% of patients experienced severe genitourinary and/or gastrointestinal toxicity that were relieved by surgical intervention. No treatment-related mortality was seen. This series suggests that 50 Gy to the whole pelvis together with three fractions of 10 Gy to point A with HDR brachytherapy is an effective fractionation schedule in the treatment of locally advanced cancer of cervix. To decrease the complications, newer devices and treatment planning may be beneficial.

  3. High-dose-rate afterloading brachytherapy in carcinoma of the cervix: an experience of 1992 patients

    International Nuclear Information System (INIS)

    Lorvidhaya, Vicharn; Tonusin, Anun; Changwiwit, Witit; Chitapanarux, Imjai; Srisomboon, Jatupol; Wanwilairat, Somsak; Chawapun, Nisa; Sukthomya, Vimol

    2000-01-01

    Purpose: To report the results of radiation therapy in carcinoma of the cervix treated by external irradiation and high-dose-rate (HDR) intracavitary brachytherapy. Methods and Materials: This is a retrospective analysis of 2063 patients with histologically proven carcinoma of the cervix treated by external irradiation and HDR intracavitary brachytherapy between March 1985-December 1991. The Kaplan-Meier method was used for survival and disease-free survival analysis. Late complications in the bowel and bladder were calculated actuarially. Results: There were 71 patients who did not complete the course of irradiation so only 1992 patients were retrospectively analyzed for survival. There were 2 patients (0.1%) in Stage IA, 211 (10.2%) Stage IB, 225 (10.9%) in Stage IIA, 902 (43.7%) in Stage IIB, 14 (0.7%) in Stage IIIA, 675 (32.7%) in Stage IIIB, 16 (0.8%) in Stage IVA, and 16 (0.8%) in Stage IVB. The median follow-up time was 96 months. The actuarial 5-year disease-free survival rate was 79.5%, 70.0%, 59.4%, 46.1%, 32.3%, 7.8%, and 23.1% for Stage IB, IIA, IIB, IIIA, IIIB, IVA, and IVB respectively. The actuarial 5-year disease-free survival rate for Stage IB 1 and IB 2 squamous cell carcinoma was 88.7% and 67.0%. The actuarial 5-year overall survival rate was 86.3%, 81.1%, 73.0%, 50.3%, 47.8%, 7.8%, and 30.8% for Stage IB, IIA, IIB, IIIA, IIIB, IVA, and IVB respectively. Pattern of failure revealed 20.8% local recurrence, 18.7% distant metastases, and 4% in both. The late complication rate Grade 3 and 4 (RTOG) for bowel and bladder combined was 7.0% with 1.9% Grade 4. Conclusion: HDR brachytherapy used in this series produced pelvic control and survival rates comparable to other LDR series

  4. Variability of Marker-Based Rectal Dose Evaluation in HDR Cervical Brachytherapy

    International Nuclear Information System (INIS)

    Wang Zhou; Jaggernauth, Wainwright; Malhotra, Harish K.; Podgorsak, Matthew B.

    2010-01-01

    In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.

  5. Preliminary results of concurrent chemotherapy and radiation therapy using high-dose-rate brachytherapy for cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Ja; Lee, Ji Hye; Lee, Re Na; Suh, Hyun Suk [Ewha Womans University College of Medicine, Seoul (Korea, Republic of)

    2006-09-15

    To determine the efficacy and safety of concurrent chemotherapy and radiation therapy with high-dose-rate brachytherapy for cervical cancer. From January 2001 to December 2002, 30 patients with cervical cancer were treated with concurrent chemotherapy (cisplatin and 5-FU) and definitive radiation therapy. The median age was 58 (range 34 {approx} 74) year old. The pathology of the biopsy sections was squamous cell carcinoma in 29 patients and one was adenocarcinoma. The distribution to FIGO staging system was as follow: stage IB, 7 (23%); IIA, 3 (10%); IIB, 12 (40%); IIIA, 3 (10%); IIIB, 5 (17%). All patients received pelvic external beam irradiation (EBRT) to a total dose of 45 {approx} 50.4 Gy (median: 50.4 Gy) over 5 {approx} 5.5 weeks. Ir-192 HDR intracavity brachytherapy (ICBT) was given after a total dose of 41.1 Gy. HDR-ICBT was performed twice a week, with a fraction point. A dose of 4 Gy and median dose to point A was 28 Gy (range: 16 {approx} 32 Gy) in 7 fractions. The median cumulative biologic effective dose (BED) at point A (EBRT + ICBT) was 88 Gy{sub 10} (range:77 {approx} 94 Gy{sub 10}). The median cumulative BED at ICRU 38 reference point (EBRT + ICBT) was 131 Gy{sub 3} (range: 122 {approx} 140 Gy{sub 3}) at point A, 109 Gy{sub 3} (range:88{approx} 125 Gy{sub 3}) at the rectum and 111 Gy{sub 3} (range: 91 {approx} 123 Gy{sub 3}) at the urinary bladder. Cisplatin (60 mg/m{sup 2}) and 5-FU (1,000 mg/m{sup 2}) was administered intravenously at 2 weeks interval from the first day of radiation for median 5 (range:2 {approx} 6) cycles. The assessment was performed at 1 month after completion of radiation therapy by clinical examination and CT scan. The median follow-up time was 36 months (range:8{approx} 50 months). The complete response rate after concurrent chemo radiation therapy was 93.3%. The 3-yr actuarial pelvic control rate was 87% and 3-yr actuarial overall survival and disease-free survival rate was 93% and 87%, respectively. The local failure

  6. Preliminary results of concurrent chemotherapy and radiation therapy using high-dose-rate brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Lee, Kyung Ja; Lee, Ji Hye; Lee, Re Na; Suh, Hyun Suk

    2006-01-01

    To determine the efficacy and safety of concurrent chemotherapy and radiation therapy with high-dose-rate brachytherapy for cervical cancer. From January 2001 to December 2002, 30 patients with cervical cancer were treated with concurrent chemotherapy (cisplatin and 5-FU) and definitive radiation therapy. The median age was 58 (range 34 ∼ 74) year old. The pathology of the biopsy sections was squamous cell carcinoma in 29 patients and one was adenocarcinoma. The distribution to FIGO staging system was as follow: stage IB, 7 (23%); IIA, 3 (10%); IIB, 12 (40%); IIIA, 3 (10%); IIIB, 5 (17%). All patients received pelvic external beam irradiation (EBRT) to a total dose of 45 ∼ 50.4 Gy (median: 50.4 Gy) over 5 ∼ 5.5 weeks. Ir-192 HDR intracavity brachytherapy (ICBT) was given after a total dose of 41.1 Gy. HDR-ICBT was performed twice a week, with a fraction point. A dose of 4 Gy and median dose to point A was 28 Gy (range: 16 ∼ 32 Gy) in 7 fractions. The median cumulative biologic effective dose (BED) at point A (EBRT + ICBT) was 88 Gy 10 (range:77 ∼ 94 Gy 10 ). The median cumulative BED at ICRU 38 reference point (EBRT + ICBT) was 131 Gy 3 (range: 122 ∼ 140 Gy 3 ) at point A, 109 Gy 3 (range:88∼ 125 Gy 3 ) at the rectum and 111 Gy 3 (range: 91 ∼ 123 Gy 3 ) at the urinary bladder. Cisplatin (60 mg/m 2 ) and 5-FU (1,000 mg/m 2 ) was administered intravenously at 2 weeks interval from the first day of radiation for median 5 (range:2 ∼ 6) cycles. The assessment was performed at 1 month after completion of radiation therapy by clinical examination and CT scan. The median follow-up time was 36 months (range:8∼ 50 months). The complete response rate after concurrent chemo radiation therapy was 93.3%. The 3-yr actuarial pelvic control rate was 87% and 3-yr actuarial overall survival and disease-free survival rate was 93% and 87%, respectively. The local failure rate was 13% and distant metastatic rate was 3.3%. The crude rate of minor hematologic

  7. Measuring the absorbed dose in critical organs during low rate dose brachytherapy with 137 Cs using thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Torres, A.; Gonzalez, P.R.; Furetta, C.; Azorin, J.; Andres, U.; Mendez, G.

    2003-01-01

    Intracavitary Brachytherapy is one of the most used methods for the treatment of the cervical-uterine cancer. This treatment consists in the insertion of low rate dose 137 Cs sources into the patient. The most used system for the treatment dose planning is that of Manchester. This planning is based on sources, which are considered fixed during the treatment. However, the experience has shown that, during the treatment, the sources could be displaced from its initial position, changing the dose from that previously prescribed. For this reason, it is necessary to make measurements of the absorbed dose to the surrounding organs (mainly bladder and rectum). This paper presents the results of measuring the absorbed dose using home-made LiF: Mg, Cu, P + Ptfe thermoluminescent dosimeters (TLD). Measurements were carried out in-vivo during 20 minutes at the beginning and at the end of the treatments. Results showed that the absorbed dose to the critical organs vary significantly due to the movement of the patient during the treatment. (Author)

  8. High dose rate brachytherapy in treatment of high grade astrocytomas

    International Nuclear Information System (INIS)

    Garcia-Alejo, R.; Delgado, J.M.; Cerro, E. del; Torres, J.J.; Martinez, R.

    1996-01-01

    From May 1994 to June 1995, 18 patients with high grade astrocytomas were entered prospectively on a selective protocol combining surgery, external beam radiotherapy, stereotactic interstitial implantation with HDR Iridium 192 and chemotherapy. Only those patients with tumor size 100cc or less average dimension, high grade astrocytoma, Karnofsky 70 or greater, unilateral, circumscribed, unifocal, tumor stable or responding to external radiation and supratentorial were included in the study. Ages ranged from 16 to 69 years. There were 13 males and 5 females. Surgery consisted of biopsy only in 3 patients, subtotal resection in 11, and gross total resection in 4 patients. Focal external beam radiation portals included the contrast enhancing mass on CT scan plus a 3 cm margin. The protocol called for minimum tumor dose of 60 Gy to be given in 2 Gy daily fractions. An interstitial brachytherapy boost was to be performed two weeks after the conclusion of external beam radiation. The dose was 30 Gy in 4 fractions. The authors analyze on basis on their personal experience, the possibilities and the limits offered by this therapeutic procedure in neuro-oncology. Using stereotactic techniques, interstitial brachytherapy of brain tumors was technically possible with negligible acute morbidity and mortality, and appeared to be effective and may provide for an increase in tumor control in selected cases

  9. Interfraction patient motion and implant displacement in prostate high dose rate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Fox, C. D.; Kron, T.; Leahy, M.; Duchesne, G.; Williams, S.; Tai, K. H.; Haworth, A.; Herschtal, A.; Foroudi, F. [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002 (Australia); Nursing Service, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002 (Australia); Department of Radiation Oncology, Peter MacCallum Cancer Centre and University of Melbourne, Melbourne, Victoria 3002 (Australia); Department of Physical Sciences, Peter MacCallum Cancer Centre and Royal Melbourne Insititute of Technology, Melbourne, Victoria 3000 (Australia); Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, Victoria 3002 (Australia); Department of Radiation Oncology, Peter MacCallum Cancer Centre and University of Melbourne, Melbourne, Victoria 3010 (Australia)

    2011-11-15

    Purpose: To quantify movement of prostate cancer patients undergoing treatment, using an in-house developed motion sensor in order to determine a relationship between patient movement and high dose rate (HDR) brachytherapy implant displacement. Methods: An electronic motion sensor was developed based on a three axis accelerometer. HDR brachytherapy treatment for prostate is delivered at this institution in two fractions 24 h apart and 22 patients were monitored for movement over the interval between fractions. The motion sensors functioned as inclinometers, monitoring inclination of both thighs, and the inclination and roll of the abdomen. The implanted HDR brachytherapy catheter set was assessed for displacement relative to fiducial markers in the prostate. Angle measurements and angle differences over a 2 s time base were binned, and the standard deviations of the resulting frequency distributions used as a metric for patient motion in each monitored axis. These parameters were correlated to measured catheter displacement using regression modeling. Results: The mean implant displacement was 12.6 mm in the caudal direction. A mean of 19.95 h data was recorded for the patient cohort. Patients generally moved through a limited range of angles with a mean of the exception of two patients who spent in excess of 2 h lying on their side. When tested for a relationship between movement in any of the four monitored axes and the implant displacement, none was significant. Conclusions: It is not likely that patient movement influences HDR prostate implant displacement. There may be benefits to patient comfort if nursing protocols were relaxed to allow patients greater freedom to move while the implant is in situ.

  10. Interfraction patient motion and implant displacement in prostate high dose rate brachytherapy

    International Nuclear Information System (INIS)

    Fox, C. D.; Kron, T.; Leahy, M.; Duchesne, G.; Williams, S.; Tai, K. H.; Haworth, A.; Herschtal, A.; Foroudi, F.

    2011-01-01

    Purpose: To quantify movement of prostate cancer patients undergoing treatment, using an in-house developed motion sensor in order to determine a relationship between patient movement and high dose rate (HDR) brachytherapy implant displacement. Methods: An electronic motion sensor was developed based on a three axis accelerometer. HDR brachytherapy treatment for prostate is delivered at this institution in two fractions 24 h apart and 22 patients were monitored for movement over the interval between fractions. The motion sensors functioned as inclinometers, monitoring inclination of both thighs, and the inclination and roll of the abdomen. The implanted HDR brachytherapy catheter set was assessed for displacement relative to fiducial markers in the prostate. Angle measurements and angle differences over a 2 s time base were binned, and the standard deviations of the resulting frequency distributions used as a metric for patient motion in each monitored axis. These parameters were correlated to measured catheter displacement using regression modeling. Results: The mean implant displacement was 12.6 mm in the caudal direction. A mean of 19.95 h data was recorded for the patient cohort. Patients generally moved through a limited range of angles with a mean of the exception of two patients who spent in excess of 2 h lying on their side. When tested for a relationship between movement in any of the four monitored axes and the implant displacement, none was significant. Conclusions: It is not likely that patient movement influences HDR prostate implant displacement. There may be benefits to patient comfort if nursing protocols were relaxed to allow patients greater freedom to move while the implant is in situ.

  11. Assessment of the feasibility of using transrectal ultrasound for postimplant dosimetry in low-dose-rate prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Davies, Rhian Siân, E-mail: rhian.s.davies@wales.nhs.uk; Perrett, Teresa; Powell, Jane; Barber, Jim; Tanguay, Jacob; Button, Michael; Cochlin, Dennis; Smith, Christian; Lester, Jason Francis

    2016-01-01

    A study was performed to establish whether transrectal ultrasound (TRUS)-based postimplant dosimetry (PID) is both practically feasible and comparable to computed tomography (CT)-based PID, recommended in current published guidelines. In total, 22 patients treated consecutively at a single cancer center with low-dose-rate (LDR) brachytherapy for early-stage prostate cancer had a transrectal ultrasound performed immediately after implant (d0-TRUS) and computed tomography scan 30 days after implant (d30-CT). Postimplant dosimetry planning was performed on both image sets and the results were compared. The interobserver reproducibility of the transrectal ultrasound postimplant dosimetry planning technique was also assessed. It was noticed that there was no significant difference in mean prostate D{sub 90} (136.5 Gy and 144.4 Gy, p = 0.2197), V{sub 100} (86.4% and 89.1%, p = 0.1480) and V{sub 150} (52.0% and 47.8%, p = 0.1657) for d30-CT and d0-TRUS, respectively. Rectal doses were significantly higher for d0-TRUS than d30-CT. Urethral doses were available with d0-TRUS only. We have shown that d0-TRUS PID is a useful tool for assessing the quality of an implant after low-dose-rate prostate brachytherapy and is comparable to d30-CT PID. There are clear advantages to its use in terms of resource and time efficiency both for the clinical team and the patient.

  12. Interstitial high-dose-rate brachytherapy boost: The feasibility and cosmetic outcome of a fractionated outpatient delivery scheme

    International Nuclear Information System (INIS)

    Manning, Matthew A.; Arthur, Douglas W.; Schmidt-Ullrich, Rupert K.; Arnfield, Mark R.; Amir, Cyrus; Zwicker, Robert D.

    2000-01-01

    Purpose: To evaluate the feasibility, potential toxicity, and cosmetic outcome of fractionated interstitial high dose rate (HDR) brachytherapy boost for the management of patients with breast cancer at increased risk for local recurrence. Methods and Materials: From 1994 to 1996, 18 women with early stage breast cancer underwent conventionally fractionated whole breast radiotherapy (50-50.4 Gy) followed by interstitial HDR brachytherapy boost. All were considered to be at high risk for local failure. Seventeen had pathologically confirmed final surgical margins of less than 2 mm or focally positive. Brachytherapy catheter placement and treatment delivery were conducted on an outpatient basis. Preplanning was used to determine optimal catheter positions to enhance dose homogeneity of dose delivery. The total HDR boost dose was 15 Gy delivered in 6 fractions of 2.5 Gy over 3 days. Local control, survival, late toxicities (LENT-SOMA), and cosmetic outcome were recorded in follow-up. In addition, factors potentially influencing cosmesis were analyzed by logistic regression analysis. Results: The minimum follow-up is 40 months with a median 50 months. Sixteen patients were alive without disease at last follow-up. There have been no in-breast failures observed. One patient died with brain metastases, and another died of unrelated causes without evidence of disease. Grade 1-2 late toxicities included 39% with hyperpigmentation, 56% with detectable fibrosis, 28% with occasional discomfort, and 11% with visible telangiectasias. Grade 3 toxicity was reported in one patient as persistent discomfort. Sixty-seven percent of patients were considered to have experienced good/excellent cosmetic outcomes. Factors with a direct relationship to adverse cosmetic outcome were extent of surgical defect (p = 0.00001), primary excision volume (p = 0.017), and total excision volume (p = 0.015). Conclusions: For high risk patients who may benefit from increased doses, interstitial HDR

  13. High-dose rate brachytherapy in the treatment of prostate cancer: acute toxicity and biochemical behavior analysis

    International Nuclear Information System (INIS)

    Esteves, Sergio Carlos Barros; Oliveira, Antonio Carlos Zuliani de; Cardoso, Herbeni; Tagawa, Eduardo Komai; Castelo, Roberto; D'Imperio, Marcio

    2006-01-01

    Objective: this study focuses on the biochemical response of the following variables: prostate volume, prostate-specific antigen (PSA) value, Gleason scores, staging, the risk of the disease, and hormone therapy. Objective: in the period between February of 1998 and July of 2001, 46 patients with prostate cancer were treated with radiotherapy, in a combination of teletherapy and high-dose rate (HDR) brachytherapy. The age ranged from 51 to 79 years (averaging 66.4 years). T1c stage was the most frequent one: 30 (65%). The Gleason score was below 7 in 78% of the patients. PSA ranged from 3.4 to 33.3, being below 10 in 39% of the cases. The average prostatic volume was 32.3 cc. Twenty-eight percent of the patients received hormone therapy. Teletherapy dose ranged from 45 to 50.4 Gy, associated to four fractions of 4 Gy of HDR brachytherapy. Results: the follow-up period varied from 6 to 43 months. Four patients missed the follow-up and four died (one due to the disease). Out of the 39 patients that were analyzed, 76% presented a less than 1.5 PSA. None of the analyzed variables were found to be of statistical significance (p > 0.05) regarding biochemical control. Conclusion: the use of HDR brachytherapy was found to be effective in the treatment of prostate cancer and, in this study, the variables considered as prognostic factors did not interfere in the biochemical control. (author)

  14. Dose reduction in LDR brachytherapy by implanted prostate gold fiducial markers.

    Science.gov (United States)

    Landry, Guillaume; Reniers, Brigitte; Lutgens, Ludy; Murrer, Lars; Afsharpour, Hossein; de Haas-Kock, Danielle; Visser, Peter; van Gils, Francis; Verhaegen, Frank

    2012-03-01

    The dosimetric impact of gold fiducial markers (FM) implanted prior to external beam radiotherapy of prostate cancer on low dose rate (LDR) brachytherapy seed implants performed in the context of combined therapy was investigated. A virtual water phantom was designed containing a single FM. Single and multi source scenarios were investigated by performing Monte Carlo dose calculations, along with the influence of varying orientation and distance of the FM with respect to the sources. Three prostate cancer patients treated with LDR brachytherapy for a recurrence following external beam radiotherapy with implanted FM were studied as surrogate cases to combined therapy. FM and brachytherapy seeds were identified on post implant CT scans and Monte Carlo dose calculations were performed with and without FM. The dosimetric impact of the FM was evaluated by quantifying the amplitude of dose shadows and the volume of cold spots. D(90) was reported based on the post implant CT prostate contour. Large shadows are observed in the single source-FM scenarios. As expected from geometric considerations, the shadows are dependent on source-FM distance and orientation. Large dose reductions are observed at the distal side of FM, while at the proximal side a dose enhancement is observed. In multisource scenarios, the importance of shadows appears mitigated, although FM at the periphery of the seed distribution caused underdosage (LDR brachytherapy seed implant dose distributions. Therefore, reduced tumor control could be expected from FM implanted in tumors, although our results are too limited to draw conclusions regarding clinical significance.

  15. Interim report of image-guided conformal high-dose-rate brachytherapy for patients with unfavorable prostate cancer: the William Beaumont Phase II dose-escalating trial

    International Nuclear Information System (INIS)

    Martinez, Alvaro A.; Kestin, Larry L.; Stromberg, Jannifer S.; Gonzalez, Jose A.; Wallace, Michelle; Gustafson, Gary S.; Edmundson, Gregory K.; Spencer, William; Vicini, Frank A.

    2000-01-01

    Purpose: We analyzed our institution's experience treating patients with unfavorable prostate cancer in a prospective Phase II dose-escalating trial of external beam radiation therapy (EBRT) integrated with conformal high-dose-rate (HDR) brachytherapy boosts. This interim report discusses treatment outcome and prognostic factors using this treatment approach. Methods and Materials: From November 1991 through February 1998, 142 patients with unfavorable prostate cancer were prospectively treated in a dose-escalating trial with pelvic EBRT in combination with outpatient HDR brachytherapy at William Beaumont Hospital. Patients with any of the following characteristics were eligible: pretreatment prostate-specific antigen (PSA) ≥ 10.0 ng/ml, Gleason score ≥ 7, or clinical stage T2b or higher. All patients received pelvic EBRT to a median total dose of 46.0 Gy. Pelvic EBRT was integrated with ultrasound-guided transperineal conformal interstitial iridium-192 HDR implants. From 1991 to 1995, 58 patients underwent three conformal interstitial HDR implants during the first, second, and third weeks of pelvic EBRT. After October 1995, 84 patients received two interstitial implants during the first and third weeks of pelvic EBRT. The dose delivered via interstitial brachytherapy was escalated from 5.50 Gy to 6.50 Gy for each implant in those patients receiving three implants, and subsequently, from 8.25 Gy to 9.50 Gy per fraction in those patients receiving two implants. To improve implant quality and reduce operator dependency, an on-line, image-guided interactive dose optimization program was utilized during each HDR implant. No patient received hormonal therapy unless treatment failure was documented. The median follow-up was 2.1 years (range: 0.2-7.2 years). Biochemical failure was defined according to the American Society for Therapeutic Radiology and Oncology Consensus Panel definition. Results: The pretreatment PSA level was ≥ 10.0 ng/ml in 51% of patients. The

  16. American Society for Radiation Oncology (ASTRO) and American College of Radiology (ACR) Practice Guideline for the Performance of High-Dose-Rate Brachytherapy

    International Nuclear Information System (INIS)

    Erickson, Beth A.; Demanes, D. Jeffrey; Ibbott, Geoffrey S.; Hayes, John K.; Hsu, I-Chow J.; Morris, David E.; Rabinovitch, Rachel A.; Tward, Jonathan D.; Rosenthal, Seth A.

    2011-01-01

    High-Dose-Rate (HDR) brachytherapy is a safe and efficacious treatment option for patients with a variety of different malignancies. Careful adherence to established standards has been shown to improve the likelihood of procedural success and reduce the incidence of treatment-related morbidity. A collaborative effort of the American College of Radiology (ACR) and American Society for Therapeutic Radiation Oncology (ASTRO) has produced a practice guideline for HDR brachytherapy. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, physicist and dosimetrists. Review of the leading indications for HDR brachytherapy in the management of gynecologic, thoracic, gastrointestinal, breast, urologic, head and neck, and soft tissue tumors is presented. Logistics with respect to the brachytherapy implant procedures and attention to radiation safety procedures and documentation are presented. Adherence to these practice guidelines can be part of ensuring quality and safety in a successful HDR brachytherapy program.

  17. Brachytherapy optimization using radiobiological-based planning for high dose rate and permanent implants for prostate cancer treatment

    Science.gov (United States)

    Seeley, Kaelyn; Cunha, J. Adam; Hong, Tae Min

    2017-01-01

    We discuss an improvement in brachytherapy--a prostate cancer treatment method that directly places radioactive seeds inside target cancerous regions--by optimizing the current standard for delivering dose. Currently, the seeds' spatiotemporal placement is determined by optimizing the dose based on a set of physical, user-defined constraints. One particular approach is the ``inverse planning'' algorithms that allow for tightly fit isodose lines around the target volumes in order to reduce dose to the patient's organs at risk. However, these dose distributions are typically computed assuming the same biological response to radiation for different types of tissues. In our work, we consider radiobiological parameters to account for the differences in the individual sensitivities and responses to radiation for tissues surrounding the target. Among the benefits are a more accurate toxicity rate and more coverage to target regions for planning high-dose-rate treatments as well as permanent implants.

  18. High-dose rate brachytherapy (HDRB) for primary or recurrent cancer in the vagina

    International Nuclear Information System (INIS)

    Beriwal, Sushil; Heron, Dwight E; Mogus, Robert; Edwards, Robert P; Kelley, Joseph L; Sukumvanich, Paniti

    2008-01-01

    The purpose of this study was to evaluate the efficacy of HDR brachytherapy for primary or recurrent vaginal cancer. Between the years 2000 to 2006, 18 patients with primary or recurrent vaginal cancer were treated with brachytherapy (HDRB). Six patients had primary vaginal cancer (stage II to IVA) while 12 were treated for isolated vaginal recurrence (primary cervix = 4, vulva = 1 and endometrium = 7). Five patients had previous pelvic radiation therapy. All except one patient received external beam radiation therapy to a median dose of 45 Gy (range 31.2–55.8 Gy). The HDRB was intracavitary using a vaginal cylinder in 5 patients and interstitial using a modified Syed-Nesblett template in 13 patients. The dose of interstitial brachytherapy was 18.75 Gy in 5 fractions delivered twice daily. The median follow-up was 18 months (range 6–66 months). Complete response (CR) was achieved in all but one patient (94%). Of these 17 patients achieving a CR, 1 had local recurrence and 3 had systemic recurrence at a median time of 6 months (range 6–22 months). The 2-year actuarial local control and cause-specific survival for the entire group were 88% and 82.5%, respectively. In subset analysis, the crude local control was 100% for primary vaginal cancer, 100% for the group with recurrence without any prior radiation and 67% for group with recurrence and prior radiation therapy. Two patients had late grade 3 or higher morbidity (rectovaginal fistula in one patient and chronic vaginal ulcer resulting in bleeding in one patient). Both these patients had prior radiation therapy. Our small series suggests that HDRB is efficacious for primary or recurrent vaginal cancer. Patients treated with primary disease and those with recurrent disease without prior irradiation have the greatest benefit from HDRB in this setting. The salvage rate for patients with prior radiation therapy is lower with a higher risk of significant complications. Additional patients and follow-up are ongoing

  19. Robustness of IPSA optimized high-dose-rate prostate brachytherapy treatment plans to catheter displacements.

    Science.gov (United States)

    Poder, Joel; Whitaker, May

    2016-06-01

    Inverse planning simulated annealing (IPSA) optimized brachytherapy treatment plans are characterized with large isolated dwell times at the first or last dwell position of each catheter. The potential of catheter shifts relative to the target and organs at risk in these plans may lead to a more significant change in delivered dose to the volumes of interest relative to plans with more uniform dwell times. This study aims to determine if the Nucletron Oncentra dwell time deviation constraint (DTDC) parameter can be optimized to improve the robustness of high-dose-rate (HDR) prostate brachytherapy plans to catheter displacements. A set of 10 clinically acceptable prostate plans were re-optimized with a DTDC parameter of 0 and 0.4. For each plan, catheter displacements of 3, 7, and 14 mm were retrospectively applied and the change in dose volume histogram (DVH) indices and conformity indices analyzed. The robustness of clinically acceptable prostate plans to catheter displacements in the caudal direction was found to be dependent on the DTDC parameter. A DTDC value of 0 improves the robustness of planning target volume (PTV) coverage to catheter displacements, whereas a DTDC value of 0.4 improves the robustness of the plans to changes in hotspots. The results indicate that if used in conjunction with a pre-treatment catheter displacement correction protocol and a tolerance of 3 mm, a DTDC value of 0.4 may produce clinically superior plans. However, the effect of the DTDC parameter in plan robustness was not observed to be as strong as initially suspected.

  20. Implementation of a High-Dose-Rate Brachytherapy Program for Carcinoma of the Cervix in Senegal: A Pragmatic Model for the Developing World

    International Nuclear Information System (INIS)

    Einck, John P.; Hudson, Alana; Shulman, Adam C.; Yashar, Catheryn M.; Dieng, Mamadou M.; Diagne, Magatte; Gueye, Latifatou; Gningue, Fama; Gaye, Pape M.; Fisher, Brandon J.; Mundt, Arno J.; Brown, Derek W.

    2014-01-01

    West Africa has one of the highest incidence rates of carcinoma of the cervix in the world. The vast majority of women do not have access to screening or disease treatment, leading to presentation at advanced stages and to high mortality rates. Compounding this problem is the lack of radiation treatment facilities in Senegal and many other parts of the African continent. Senegal, a country of 13 million people, had a single 60 Co teletherapy unit before our involvement and no brachytherapy capabilities. Radiating Hope, a nonprofit organization whose mission is to provide radiation therapy equipment to countries in the developing world, provided a high-dose-rate afterloading unit to the cancer center for curative cervical cancer treatment. Here we describe the implementation of high-dose-rate brachytherapy in Senegal requiring a nonstandard fractionation schedule and a novel treatment planning approach as a possible blueprint to providing this technology to other developing countries

  1. Implementation of a High-Dose-Rate Brachytherapy Program for Carcinoma of the Cervix in Senegal: A Pragmatic Model for the Developing World

    Energy Technology Data Exchange (ETDEWEB)

    Einck, John P., E-mail: jeinck@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Hudson, Alana [Department of Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta (Canada); Shulman, Adam C. [Overlook Medical Center, Summit, New Jersey (United States); Yashar, Catheryn M. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Dieng, Mamadou M.; Diagne, Magatte; Gueye, Latifatou; Gningue, Fama; Gaye, Pape M. [Départemént de Radiothérapie, Institut Joliot-Curie, Hôpital Aristide Le Dantec, Dakar (Senegal); Fisher, Brandon J. [GammaWest Cancer Services, Salt Lake City, Utah (United States); Mundt, Arno J. [Department of Radiation Medicine and Applied Sciences, University of California San Diego, San Diego, California (United States); Brown, Derek W. [Department of Oncology, Tom Baker Cancer Centre, University of Calgary, Calgary, Alberta (Canada)

    2014-07-01

    West Africa has one of the highest incidence rates of carcinoma of the cervix in the world. The vast majority of women do not have access to screening or disease treatment, leading to presentation at advanced stages and to high mortality rates. Compounding this problem is the lack of radiation treatment facilities in Senegal and many other parts of the African continent. Senegal, a country of 13 million people, had a single {sup 60}Co teletherapy unit before our involvement and no brachytherapy capabilities. Radiating Hope, a nonprofit organization whose mission is to provide radiation therapy equipment to countries in the developing world, provided a high-dose-rate afterloading unit to the cancer center for curative cervical cancer treatment. Here we describe the implementation of high-dose-rate brachytherapy in Senegal requiring a nonstandard fractionation schedule and a novel treatment planning approach as a possible blueprint to providing this technology to other developing countries.

  2. Treatment of skin carcinomas of the face by high-dose-rate brachytherapy and custom-made surface molds

    International Nuclear Information System (INIS)

    Guix, Benjamin; Finestres, Fernando; Tello, Jose-Ignacio; Palma, Cesar; Martinez, Antonio; Guix, Jose-Ramon; Guix, Ricardo

    2000-01-01

    Purpose: To analyze the results obtained in a prospective group of patients with basal or squamous cell skin carcinomas of the face treated by high-dose-rate (HDR) brachytherapy via custom-made surface molds. Methods and Materials: A total of 136 patients with basal or squamous cell carcinomas of the face were treated between March 1992 and March 1997 by surface molds and HDR brachytherapy with iridium-192. Nineteen patients were treated with standard Brock applicators and 117 patients with custom-made polymethyl methacrylate applicators, built over a plaster mold obtained of the patient's face. Minimum dose administered to the tumor was 6000 to 6500 cGy in 33 to 36 fractions at 180 cGy/fraction in lesions of up to 4 cm. Lesions greater than 4 cm were boosted up to 7500-8000 cGy after a 3-week pause. Results: With the custom-made surface molds, the dose distribution was uniform in the surface of the skin and at 5 mm depth in the whole area of the applicator. Differences between the areas of maximum and minimum dose at this depth never reached values higher than 5% of the prescribed dose. At the edges of the custom-made molds dose gradient was sharp, with the detected dose at 5 mm from the applicator being negligible. All the patients were complete responders. There were 3 local recurrences, 1/73 patients treated for primary tumor and 2/63 patients treated for recurrent tumor. Actuarial local control at 5 years for all patients was 98%, for those patients with primary tumors 99%, and for recurrent patients 87%. The treatment tolerance was excellent in all cases. No severe, early, or late, complications were detected. Conclusions: Radiotherapy is a highly effective treatment of skin carcinomas of the face. Custom-made molds, to be used in conjunction with HDR brachytherapy equipment, make possible a uniform dose distribution, with a sharp dose gradient in the limits of applicators. Custom-made surface molds are easy and safe to use, and they fit very accurately for

  3. Quality assurance for high dose rate brachytherapy treatment planning optimization: using a simple optimization to verify a complex optimization

    International Nuclear Information System (INIS)

    Deufel, Christopher L; Furutani, Keith M

    2014-01-01

    As dose optimization for high dose rate brachytherapy becomes more complex, it becomes increasingly important to have a means of verifying that optimization results are reasonable. A method is presented for using a simple optimization as quality assurance for the more complex optimization algorithms typically found in commercial brachytherapy treatment planning systems. Quality assurance tests may be performed during commissioning, at regular intervals, and/or on a patient specific basis. A simple optimization method is provided that optimizes conformal target coverage using an exact, variance-based, algebraic approach. Metrics such as dose volume histogram, conformality index, and total reference air kerma agree closely between simple and complex optimizations for breast, cervix, prostate, and planar applicators. The simple optimization is shown to be a sensitive measure for identifying failures in a commercial treatment planning system that are possibly due to operator error or weaknesses in planning system optimization algorithms. Results from the simple optimization are surprisingly similar to the results from a more complex, commercial optimization for several clinical applications. This suggests that there are only modest gains to be made from making brachytherapy optimization more complex. The improvements expected from sophisticated linear optimizations, such as PARETO methods, will largely be in making systems more user friendly and efficient, rather than in finding dramatically better source strength distributions. (paper)

  4. The prediction of late rectal complications in patients treated with high dose-rate brachytherapy for carcinoma of the cervix

    International Nuclear Information System (INIS)

    Clark, Brenda G.; Souhami, Luis; Roman, Ted N.; Chappell, Rick; Evans, Michael D.C.; Fowler, Jack F.

    1997-01-01

    Purpose: The aim of this work is to investigate an unusually high rate of late rectal complications in a group of 43 patients treated with concomitant irradiation and chemotherapy for carcinoma of the cervix between December 1988 and April 1991, with a view to identifying predictive factors. Methods and Materials: The biologically effective dose received by each patient to the rectal reference point defined by the International Commission of Radiation Units and Measurements, Report 38, were calculated. Radiotherapy consisted of 46 Gy external beam irradiation plus three high dose-rate intracavitary treatments of 10 Gy each prescribed to point A. Cisplatin 30 mg/m 2 was given weekly throughout the duration of the irradiation. The results have been compared to data from 119 patients treated with irradiation alone to assess the confounding effect of the cisplatin. Results: The relationship between the biologically effective dose delivered to the rectal reference point and the development of late complications shows a strong dose-response with a threshold for complications occurring at approximately 125 Gy 3 corresponding to a brachytherapy dose of approximately 8 Gy per fraction. This value is approximately the same biologically effective dose threshold as that found for external beam irradiation in the head and neck region. The data from the group of patients treated without cisplatin is comparable to the data from the first group of patients in the lower dose ranges; the higher doses were not used and thus are not available for comparison. Conclusion: Using the linear quadratic model applied to our clinical results, we have established a threshold for late rectal complications for patients treated with external beam irradiation and high dose-rate brachytherapy for carcinoma of the cervix. This threshold is consistent with similar data for external beam irradiation in the head and neck region

  5. High-Dose-Rate Brachytherapy Boost for Prostate Cancer: Comparison of Two Different Fractionation Schemes

    International Nuclear Information System (INIS)

    Kaprealian, Tania; Weinberg, Vivian; Speight, Joycelyn L.; Gottschalk, Alexander R.; Roach, Mack; Shinohara, Katsuto; Hsu, I.-Chow

    2012-01-01

    Purpose: This is a retrospective study comparing our experience with high-dose-rate (HDR) brachytherapy boost for prostate cancer, using two different fractionation schemes, 600 cGy × 3 fractions (patient group 1) and 950 cGy × 2 fractions (patient group 2). Methods and Materials: A total of 165 patients were treated for prostate cancer using external beam radiation therapy up to a dose of 45 Gy, followed by an HDR brachytherapy prostate radiation boost. Between July 1997 and Nov 1999, 64 patients were treated with an HDR boost of 600 cGy × 3 fractions; and between June 2000 and Nov 2005, 101 patients were treated with an HDR boost of 950 cGy × 2 fractions. All but 9 patients had at least one of the following risk features: pretreatment prostate-specific antigen (PSA) level >10, a Gleason score ≥7, and/or clinical stage T3 disease. Results: Median follow-up was 105 months for group 1 and 43 months for group 2. Patients in group 2 had a greater number of high-risk features than group 1 (p = 0.02). Adjusted for comparable follow-up, there was no difference in biochemical no-evidence-of-disease (bNED) rate between the two fractionation scheme approaches, with 5-year Kaplan-Meier estimates of 93.5% in group 1 and 87.3% in group 2 (p = 0.19). The 5-year estimates of progression-free survival were 86% for group 1 and 83% for group 2 (p = 0.53). Among high-risk patients, there were no differences in bNED or PFS rate due to fractionation. Conclusions: Results were excellent for both groups. Adjusted for comparable follow-up, no differences were found between groups.

  6. Proposal of a postal system for Ir-192 sources calibration used in high dose rate brachytherapy with LiF:Mn:Ti thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Vieira, W.S.; Borges, J.C.; Almeida, C.E.V.

    1998-01-01

    A proposal in order to improve the brachytherapy quality control and to allow postal intercomparison of Ir-192 sources used in high dose rate brachytherapy has been presented. The LiF: Mn: Ti (TLD 100) detector has been selected for such purpose. The experimental array and the TLDs irradiation and calibration techniques, at the treatment units, have been specified in the light of more recent methodology of Ir-192 calibration sources. (Author)

  7. Direct determination of the absorbed dose to water from 125I low dose-rate brachytherapy seeds using the new absorbed dose primary standard developed at ENEA-INMRI

    International Nuclear Information System (INIS)

    Toni, M.P.; Pimpinella, M.; Pinto, M.; Quini, M.; Cappadozzi, G.; Silvestri, C.; Bottauscio, O.

    2012-01-01

    Low-intensity radioactive sources emitting low-energy photons are used in the clinic for low dose-rate brachytherapy treatments of tumours. The dosimetry of these sources is based on reference air kerma rate measurements. The absorbed dose rate to water at the reference depth d 0 = 1 cm, D w , 1 cm, is then obtained by a conversion procedure with a large relative standard uncertainty of about 5%. This paper describes a primary standard developed at ENEA-INMRI to directly measure D w , 1 cm due to LDR sources. The standard is based on a large-angle and variable-volume ionization chamber, embedded in a graphite phantom and operating under 'wall-less air chamber' conditions. A set of correction and conversion factors, based on experiments and Monte Carlo simulations, are determined to obtain the value of D w , 1 cm from measurements of increment of ionization current with increasing chamber volume. The relative standard uncertainty on D w , 1 cm is 2.6%, which is appreciably lower than the current uncertainty. Characteristics of the standard, its associated uncertainty budget, and some experimental results are given for 125 I BEBIG I25.S16.C brachytherapy seeds. Finally, results of the experimental determination of the dose-rate constant 1 cm, traceable to the D w , 1 cm and the low-energy air kerma ENEA-INMRI standards, are given. The relative standard uncertainty on 1 cm is 2.9%, appreciably lower than the typical uncertainty (4.8%) of the values available in the literature. (authors)

  8. Construction balance analysis of dose rate medium brachytherapy TDS

    International Nuclear Information System (INIS)

    Sandi Parapak

    2011-01-01

    One of the most important part of brachytherapy instrument design activities is analyze by determining the centroid point of construction in order to maintain the balance of brachytherapy instrument, either during operation as well as when transported. Operation of brachytherapy is not only done in one place so it is necessary to balance the analysis of the forces at the time did not move, moved on the horizontal floor and sloping floor. Calculation approach who is done to calculate the weight of mechanical components on each module, and then calculate the centroid of each module, for the balance of forces analysis performed with the assumption at the time of brachytherapy in the position of not moving on a horizontal floor, moved from a place to another on the horizontal floor and on the floor with sloping angle 30°. Base on the results of this analysis are expected to balance the four wheels can move without slipping at the time of decline or incline. Also, results of analysis can be used in designing a mobile construction brachytherapy taking into consideration the aesthetic ideal, easy to operate, ensure the safety of equipment, operator and patient. (author)

  9. Dose specification for 192Ir high dose rate brachytherapy in terms of dose-to-water-in-medium and dose-to-medium-in-medium

    International Nuclear Information System (INIS)

    Fonseca, Gabriel Paiva; Yoriyaz, Hélio; Tedgren, Åsa Carlsson; Nilsson, Josef; Persson, Maria; Reniers, Brigitte; Verhaegen, Frank

    2015-01-01

    Dose calculation in high dose rate brachytherapy with 192 Ir is usually based on the TG-43U1 protocol where all media are considered to be water. Several dose calculation algorithms have been developed that are capable of handling heterogeneities with two possibilities to report dose: dose-to-medium-in-medium (D m,m ) and dose-to-water-in-medium (D w,m ). The relation between D m,m and D w,m for 192 Ir is the main goal of this study, in particular the dependence of D w,m on the dose calculation approach using either large cavity theory (LCT) or small cavity theory (SCT). A head and neck case was selected due to the presence of media with a large range of atomic numbers relevant to tissues and mass densities such as air, soft tissues and bone interfaces. This case was simulated using a Monte Carlo (MC) code to score: D m,m, D w,m (LCT), mean photon energy and photon fluence. D w,m (SCT) was derived from MC simulations using the ratio between the unrestricted collisional stopping power of the actual medium and water. Differences between D m,m and D w,m (SCT or LCT) can be negligible (<1%) for some tissues e.g. muscle and significant for other tissues with differences of up to 14% for bone. Using SCT or LCT approaches leads to differences between D w,m (SCT) and D w,m (LCT) up to 29% for bone and 36% for teeth. The mean photon energy distribution ranges from 222 keV up to 356 keV. However, results obtained using mean photon energies are not equivalent to the ones obtained using the full, local photon spectrum. This work concludes that it is essential that brachytherapy studies clearly report the dose quantity. It further shows that while differences between D m,m and D w,m (SCT) mainly depend on tissue type, differences between D m,m and D w,m (LCT) are, in addition, significantly dependent on the local photon energy fluence spectrum which varies with distance to implanted sources. (paper)

  10. A method to combine three dimensional dose distributions for external beam and brachytherapy radiation treatments for gynecological neoplasms

    International Nuclear Information System (INIS)

    Narayana, V.; Sahijdak, W.M.; Orton, C.G.

    1997-01-01

    Purpose: Radiation treatment of gynecological neoplasms, such as cervical carcinoma, usually combines external radiation therapy with one or more intracavitary brachytherapy applications. Although the dose from external beam radiation therapy and brachytherapy can be calculated and displayed in 3D individually, the dose distributions are not combined. At most, combined point doses are calculated for select points using various time-dose models. In this study, we present a methodology to combine external beam and brachytherapy treatments for gynecological neoplasms. Material and Methods: Three dimensional bio-effect treatment planning to obtain complication probability has been outlined. CT scans of the patient's pelvis with the gynecological applicator in place are used to outline normal tissue and tumor volumes. 3D external beam and brachytherapy treatment plans are developed separately and an external beam dose matrix and a brachytherapy dose matrix was calculated. The dose in each voxel was assumed to be homogeneous. The physical dose in each voxel of the dose matrix was then converted into extrapolated response dose (ERD) based on the linear quadratic model that accounts for the dose per fraction, number of fractions, dose rate, and complete or incomplete repair of sublethal damage (time between fractions). The net biological dose delivered was obtained by summing the ERD grids from external beam and brachytherapy since there was complete repair of sublethal damage between external beam and brachytherapy treatments. The normal tissue complication probability and tumor control probability were obtained using the biological dose matrix based on the critical element model. Results: The outlined method of combining external beam and brachytherapy treatments was implemented on gynecological treatments using an applicator for brachytherapy treatments. Conclusion: Implementation of the biological dose calculation that combine different modalities is extremely useful

  11. Role of vaginal pallor reaction in predicting late vaginal stenosis after high-dose-rate brachytherapy in treatment-naive patients with cervical cancer.

    Science.gov (United States)

    Yoshida, Ken; Yamazaki, Hideya; Nakamura, Satoaki; Masui, Koji; Kotsuma, Tadayuki; Akiyama, Hironori; Tanaka, Eiichi; Yoshikawa, Nobuhiko; Uesugi, Yasuo; Shimbo, Taiju; Narumi, Yoshifumi; Yoshioka, Yasuo

    2015-07-01

    To assess actual rates of late vaginal stenosis and identify predisposing factors for complications among patients with previously untreated cervical cancer following high-dose-rate brachytherapy. We performed longitudinal analyses of 57 patients using the modified Dische score at 6, 12, 18, 24, 36, and 60 months after treatment, which consisted of 15 interstitial brachytherapys and 42 conventional intracavitary brachytherapys, with a median follow-up time of 36 months (range, 6 to 144 months). More than half of the patients developed grade 1 (mild) vaginal stenosis within the first year of follow-up, and grade 2 (97.5%, moderate) to grade 3 (severe) stenosis gradually increased with time. Actual stenosis rates for grade 1, 2, and 3 were 97.5% (95% confidence interval [CI], 92.7 to 97.5), 60.7% (95% CI, 42.2 to 79.3), and 7.4% (95% CI, 0 to 18.4) at 3 years after treatment. Pallor reaction grade 2-3 at 6 months was only a statistically significant predisposing factor for grade 2-3 late vaginal stenosis 3 years or later with a hazard ratio of 3.48 (95% CI, 1.32 to 9.19; p=0.018) by a multivariate Cox proportional hazard model. Patients with grade 0-1 pallor reaction at 6 months showed a grade ≥2 vaginal stenosis rate of 53%, whereas the grade 2-3 pallor reaction group achieved a grade ≥2 vaginal stenosis rate at 3 years at 100% (p=0.001). High-dose-rate brachytherapy was associated with high incidence of late vaginal stenosis. Pallor reaction grade 2-3 at 6 months was predictive of late grade 2-3 vaginal stenosis at 3 years after treatment. These findings should prove helpful for patient counseling and preventive intervention.

  12. Clinically evident fat necrosis in women treated with high-dose-rate brachytherapy alone for early-stage breast cancer

    International Nuclear Information System (INIS)

    Wazer, David E.; Lowther, David; Boyle, Teresa; Ulin, Kenneth; Neuschatz, Andrew; Ruthazer, Robin; DiPetrillo, Thomas A.

    2001-01-01

    Purpose: To investigate the incidence of and variables associated with clinically evident fat necrosis in women treated on a protocol of high-dose-rate (HDR) brachytherapy alone without external-beam whole-breast irradiation for early-stage breast carcinoma. Methods and Materials: From 6/1997 until 8/1999, 30 women diagnosed with Stage I or II breast carcinoma underwent surgical excision and postoperative irradiation via HDR brachytherapy implant as part of a multi-institutional clinical Phase I/II protocol. Patients eligible included those with T1, T2, N0, N1 (≤3 nodes positive), M0 tumors of nonlobular histology with negative surgical margins, no extracapsular lymph-node extension, and a negative postexcision mammogram. Brachytherapy catheters were placed at the initial excision, re-excision, or at the time of axillary sampling. Direct visualization, surgical clips, ultrasound, or CT scans assisted in delineating the target volume defined as the excision cavity plus 2-cm margin. High activity 192 Ir (3-10 Ci) was used to deliver 340 cGy per fraction, 2 fractions per day, for 5 consecutive days to a total dose of 34 Gy to the target volume. Source position and dwell times were calculated using standard volume optimization techniques. Dosimetric analyses were performed with three-dimensional postimplant dose and volume reconstructions. The median follow-up of all patients was 24 months (range, 12-36 months). Results: Eight patients (crude incidence of 27%) developed clinically evident fat necrosis postimplant in the treated breast. Fat necrosis was determined by clinical presentation including pain and swelling in the treated volume, computed tomography, and/or biopsy. All symptomatic patients (7 of 8 cases) were successfully treated with 3 to 12 months of conservative management. Continuous variables that were found to be associated significantly with fat necrosis included the number of source dwell positions (p=0.04), and the volume of tissue which received

  13. Patient effective dose from endovascular brachytherapy with 192Ir Sources

    International Nuclear Information System (INIS)

    Perna, L.; Bianchi, C.; Novario, R.; Nicolini, G.; Tanzi, F.; Conte, L.

    2002-01-01

    The growing use of endovascular brachytherapy has been accompanied by the publication of a large number of studies in several fields, but few studies on patient dose have been found in the literature. Moreover, these studies were carried out on the basis of Monte Carlo simulation. The aim of the present study was to estimate the effective dose to the patient undergoing endovascular brachytherapy treatment with 192 Ir sources, by means of experimental measurements. Two standard treatments were taken into account: an endovascular brachytherapy of the coronary artery corresponding to the activity x time product of 184 GBq.min and an endovascular brachytherapy of the renal artery (898 GBq.min). Experimental assessment was accomplished by thermoluminescence dosemeters positioned in more than 300 measurement points in a properly adapted Rando phantom. A method has been developed to estimate the mean organ doses for all tissues and organs concerned in order to calculate the effective dose associated with intravascular brachytherapy. The normalised organ doses resulting from coronary treatment were 2.4x10 -2 mSv.GBq -1 .min -1 for lung, 0.9x10 -2 mSv.GBq -1 .min -1 for oesophagus and 0.48x10 -2 mSv.GBq -1 .min -1 for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2x10 -2 mSv.GBq -1 .min -1 for colon, 7.8x10 -2 mSv.GBq -1 .min -1 for stomach and 1.7x10 -2 mSv.GBq -1 .min -1 for liver. Coronary treatment involved an effective dose of 0.046 mSv.GBq -1 .min -1 , whereas the treatment of the renal artery resulted in an effective dose of 0.15 mSv.GBq -1 .min -1 ; there were many similarities with data from former studies. Based on these results it can be concluded that the dose level of patients exposed during brachytherapy treatment is low. (author)

  14. Post-operative high dose rate vaginal apex brachytherapy in stage I endometrial adenocarcinoma

    International Nuclear Information System (INIS)

    Gumbs, A.A.; Turner, B.C.; Knisely, J.P.S.; Kacinski, B.M.; Roberts, K.B.; Peschel, R.E.; Haffty, B.G.; Rutherford, T.J.; Edraki, B.; Schwartz, P.E.; Wilson, L.D.

    1996-01-01

    Purpose/Objective: Patients with Stage I endometrial adenocarcinoma have traditionally been treated with total abdominal hysterectomy/bilateral salpingo-oophorectomy and radiation. The reported incidence of local recurrence in surgically treated patients with FIGO Stage IA or IB endometrial adenocarcinoma is 4-10% at 2 years. Combined surgery and radiation has resulted in a reduction of recurrence to 2-6%. We report the presentation, actuarial survival, actuarial rate of local failure, salvage rate, and complications for patients undergoing high dose rate (HDR) vaginal apex brachytherapy following surgery. Materials and Methods: Between 1985 and 1994 a total of 286 patients with FIGO Stage I endometrioid uterine adenocarcinoma were treated with HDR Ir-192 vaginal apex brachytherapy alone to a total dose of 21 Gy in 3 fractions at 0.5 cm from the vaginal mucosa. The pathologic stage by treatment group was IA: 31%, IB: 68%, and IC: 1%. The histologic grade of the patient's tumors was grade 1: 69%, 2: 29%, and 3: 2% of patients. The median time from surgery to radiation was 34 days (range 14-66 days). The median follow-up for 286 patients with Stage IA (92 patients), IB (190 patients), and IC (4 patients) was respectively, 37, 35 and 40 months (2 patients lost to follow-up prior to 6 months). Results: Patients presented with vaginal bleeding (94%) or abnormal pap smear (6%) at a median age for Stage IA and IB, of 54 and 63 years, respectively (range 32-88). The 5-year overall actuarial survival rate was 94.5%. The 5-year actuarial survival rate by histologic grade was 97.5% and 91.5% for FIGO grade 1 and 2, respectively (p=.011). The 5-year actuarial survival rate by depth of myometrial invasion was 99.0% and 92.5% for Stage IA and IB, respectively (p=.029). Median overall time to failure is 19.5 months (range 10-36 months). The 5-year actuarial rate of local failure was 4.5%. The overall failure rate in our study group was 2.8% (8 patients), local failure only 1

  15. A Dose-Volume Analysis of Magnetic Resonance Imaging-Aided High-Dose-Rate Image-Based Interstitial Brachytherapy for Uterine Cervical Cancer

    International Nuclear Information System (INIS)

    Yoshida, Ken; Yamazaki, Hideya; Takenaka, Tadashi; Kotsuma, Tadayuki; Yoshida, Mineo; Furuya, Seiichi; Tanaka, Eiichi; Uegaki, Tadaaki; Kuriyama, Keiko; Matsumoto, Hisanobu; Yamada, Shigetoshi; Ban, Chiaki

    2010-01-01

    Purpose: To investigate the feasibility of our novel image-based high-dose-rate interstitial brachytherapy (HDR-ISBT) for uterine cervical cancer, we evaluated the dose-volume histogram (DVH) according to the recommendations of the Gynecological GEC-ESTRO Working Group for image-based intracavitary brachytherapy (ICBT). Methods and Materials: Between June 2005 and June 2007, 18 previously untreated cervical cancer patients were enrolled. We implanted magnetic resonance imaging (MRI)-available plastic applicators by our unique ambulatory technique. Total treatment doses were 30-36 Gy (6 Gy per fraction) combined with external beam radiotherapy (EBRT). Treatment plans were created based on planning computed tomography with MRI as a reference. DVHs of the high-risk clinical target volume (HR CTV), intermediate-risk CTV (IR CTV), and the bladder and rectum were calculated. Dose values were biologically normalized to equivalent doses in 2-Gy fractions (EQD 2 ). Results: The median D90 (HR CTV) and D90 (IR CTV) per fraction were 6.8 Gy (range, 5.5-7.5) and 5.4 Gy (range, 4.2-6.3), respectively. The median V100 (HR CTV) and V100 (IR CTV) were 98.4% (range, 83-100) and 81.8% (range, 64-93.8), respectively. When the dose of EBRT was added, the median D90 and D100 of HR CTV were 80.6 Gy (range, 65.5-96.6) and 62.4 Gy (range, 49-83.2). The D 2cc of the bladder was 62 Gy (range, 51.4-89) and of the rectum was 65.9 Gy (range, 48.9-76). Conclusions: Although the targets were advanced and difficult to treat effectively by ICBT, MRI-aided image-based ISBT showed favorable results for CTV and organs at risk compared with previously reported image-based ICBT results.

  16. A dose-volume analysis of magnetic resonance imaging-aided high-dose-rate image-based interstitial brachytherapy for uterine cervical cancer.

    Science.gov (United States)

    Yoshida, Ken; Yamazaki, Hideya; Takenaka, Tadashi; Kotsuma, Tadayuki; Yoshida, Mineo; Furuya, Seiichi; Tanaka, Eiichi; Uegaki, Tadaaki; Kuriyama, Keiko; Matsumoto, Hisanobu; Yamada, Shigetoshi; Ban, Chiaki

    2010-07-01

    To investigate the feasibility of our novel image-based high-dose-rate interstitial brachytherapy (HDR-ISBT) for uterine cervical cancer, we evaluated the dose-volume histogram (DVH) according to the recommendations of the Gynecological GEC-ESTRO Working Group for image-based intracavitary brachytherapy (ICBT). Between June 2005 and June 2007, 18 previously untreated cervical cancer patients were enrolled. We implanted magnetic resonance imaging (MRI)-available plastic applicators by our unique ambulatory technique. Total treatment doses were 30-36 Gy (6 Gy per fraction) combined with external beam radiotherapy (EBRT). Treatment plans were created based on planning computed tomography with MRI as a reference. DVHs of the high-risk clinical target volume (HR CTV), intermediate-risk CTV (IR CTV), and the bladder and rectum were calculated. Dose values were biologically normalized to equivalent doses in 2-Gy fractions (EQD(2)). The median D90 (HR CTV) and D90 (IR CTV) per fraction were 6.8 Gy (range, 5.5-7.5) and 5.4 Gy (range, 4.2-6.3), respectively. The median V100 (HR CTV) and V100 (IR CTV) were 98.4% (range, 83-100) and 81.8% (range, 64-93.8), respectively. When the dose of EBRT was added, the median D90 and D100 of HR CTV were 80.6 Gy (range, 65.5-96.6) and 62.4 Gy (range, 49-83.2). The D(2cc) of the bladder was 62 Gy (range, 51.4-89) and of the rectum was 65.9 Gy (range, 48.9-76). Although the targets were advanced and difficult to treat effectively by ICBT, MRI-aided image-based ISBT showed favorable results for CTV and organs at risk compared with previously reported image-based ICBT results. (c) 2010 Elsevier Inc. All rights reserved.

  17. A real-time in vivo dosimetric verification method for high-dose rate intracavitary brachytherapy of nasopharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Qi Zhenyu; Deng Xiaowu; Cao Xinping; Huang Shaomin; Lerch, Michael; Rosenfeld, Anatoly [State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060 (China) and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou 510060 (China); Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia)

    2012-11-15

    Purpose: A real-time in vivo dosimetric verification method using metal-oxide-semiconductor field effect transistor (MOSFET) dosimeters has been developed for patient dosimetry in high-dose rate (HDR) intracavitary brachytherapy of nasopharyngeal carcinoma (NPC). Methods: The necessary calibration and correction factors for MOSFET measurements in {sup 192}Iridium source were determined in a water phantom. With the detector placed inside a custom-made nasopharyngeal applicator, the actual dose delivered to the tumor was measured in vivo and compared to the calculated values using a commercial brachytherapy planning system. Results: Five MOSFETs were independently calibrated with the HDR source, yielding calibration factors of 0.48 {+-} 0.007 cGy/mV. The maximum sensitivity variation was no more than 7% in the clinically relevant distance range of 1-5 cm from the source. A total of 70 in vivo measurements in 11 NPC patients demonstrated good agreement with the treatment planning. The mean differences between the planned and the actually delivered dose within a single treatment fraction were -0.1%{+-} 3.8% and -0.1%{+-} 3.7%, respectively, for right and left side assessments. The maximum dose deviation was less than 8.5%. Conclusions: In vivo measurement using the real-time MOSFET dosimetry system is possible to evaluate the actual dose to the tumor received by the patient during a treatment fraction and thus can offer another line of security to detect and prevent large errors.

  18. Long term results of a prospective dose escalation phase-II trial: Interstitial pulsed-dose-rate brachytherapy as boost for intermediate- and high-risk prostate cancer

    International Nuclear Information System (INIS)

    Lettmaier, Sebastian; Lotter, Michael; Kreppner, Stephan; Strnad, Annedore; Fietkau, Rainer; Strnad, Vratislav

    2012-01-01

    Purpose: We reviewed our seven year single institution experience with pulsed dose rate brachytherapy dose escalation study in patients with intermediate and high risk prostate cancer. Materials and methods: We treated a total of 130 patients for intermediate and high risk prostate cancer at our institution between 2000 and 2007 using PDR-brachytherapy as a boost after conformal external beam radiation therapy to 50.4 Gy. The majority of patients had T2 disease (T1c 6%, T2 75%, T3 19%). Seventy three patients had intermediate-risk and 53 patients had high-risk disease according to the D’Amico classification. The dose of the brachytherapy boost was escalated from 25 to 35 Gy – 33 pts. received 25 Gy (total dose 75 Gy), 63 pts. 30 Gy (total dose 80 Gy) and 34 pts. 35 Gy, (total dose 85 Gy) given in one session (dose per pulse was 0.60 Gy or 0.70 Gy/h, 24 h per day, night and day, with a time interval of 1 h between two pulses). PSA-recurrence-free survival according to Kaplan–Meier using the Phoenix definition of biochemical failure was calculated and also late toxicities according to Common Toxicity Criteria scale were assessed. Results: At the time of analysis with a median follow-up of 60 months biochemical control was achieved by 88% of patients – only 16/130 patients (12.3%) developed a biochemical relapse. Biochemical relapse free survival calculated according to Kaplan–Meier for all patients at 5 years was 85.6% (83.9% for intermediate-risk patients and 84.2% for high-risk patients) and at 9 years’ follow up it was 79.0%. Analysing biochemical relapse free survival separately for different boost dose levels, at 5 years it was 97% for the 35 Gy boost dose and 82% for the 25 and 30 Gy dose levels. The side effects of therapy were negligible: There were 18 cases (15%) of grade 1/2 rectal proctitis, one case (0.8%) of grade 3 proctitis, 18 cases (15%) of grade 1/2 cystitis, and no cases (0%) with dysuria grade 3. No patient had a bulbourethral

  19. Comparison of methods for the measurement of radiation dose distributions in high dose rate (HDR) brachytherapy: Ge-doped optical fiber, EBT3 Gafchromic film, and PRESAGE® radiochromic plastic

    International Nuclear Information System (INIS)

    Palmer, A. L.; Di Pietro, P.; Alobaidli, S.; Issa, F.; Doran, S.; Bradley, D.; Nisbet, A.

    2013-01-01

    Purpose: Dose distribution measurement in clinical high dose rate (HDR) brachytherapy is challenging, because of the high dose gradients, large dose variations, and small scale, but it is essential to verify accurate treatment planning and treatment equipment performance. The authors compare and evaluate three dosimetry systems for potential use in brachytherapy dose distribution measurement: Ge-doped optical fibers, EBT3 Gafchromic film with multichannel analysis, and the radiochromic material PRESAGE ® with optical-CT readout. Methods: Ge-doped SiO 2 fibers with 6 μm active core and 5.0 mm length were sensitivity-batched and their thermoluminescent properties used via conventional heating and annealing cycles. EBT3 Gafchromic film of 30 μm active thickness was calibrated in three color channels using a nominal 6 MV linear accelerator. A 48-bit transmission scanner and advanced multichannel analysis method were utilized to derive dose measurements. Samples of the solid radiochromic polymer PRESAGE ® , 60 mm diameter and 100 mm height, were analyzed with a parallel beam optical CT scanner. Each dosimetry system was used to measure the dose as a function of radial distance from a Co-60 HDR source, with results compared to Monte Carlo TG-43 model data. Each system was then used to measure the dose distribution along one or more lines through typical clinical dose distributions for cervix brachytherapy, with results compared to treatment planning system (TPS) calculations. Purpose-designed test objects constructed of Solid Water and held within a full-scatter water tank were utilized. Results: All three dosimetry systems reproduced the general shape of the isolated source radial dose function and the TPS dose distribution. However, the dynamic range of EBT3 exceeded those of doped optical fibers and PRESAGE ® , and the latter two suffered from unacceptable noise and artifact. For the experimental conditions used in this study, the useful range from an isolated

  20. Comparison of methods for the measurement of radiation dose distributions in high dose rate (HDR) brachytherapy: Ge-doped optical fiber, EBT3 Gafchromic film, and PRESAGE® radiochromic plastic.

    Science.gov (United States)

    Palmer, A L; Di Pietro, P; Alobaidli, S; Issa, F; Doran, S; Bradley, D; Nisbet, A

    2013-06-01

    Dose distribution measurement in clinical high dose rate (HDR) brachytherapy is challenging, because of the high dose gradients, large dose variations, and small scale, but it is essential to verify accurate treatment planning and treatment equipment performance. The authors compare and evaluate three dosimetry systems for potential use in brachytherapy dose distribution measurement: Ge-doped optical fibers, EBT3 Gafchromic film with multichannel analysis, and the radiochromic material PRESAGE(®) with optical-CT readout. Ge-doped SiO2 fibers with 6 μm active core and 5.0 mm length were sensitivity-batched and their thermoluminescent properties used via conventional heating and annealing cycles. EBT3 Gafchromic film of 30 μm active thickness was calibrated in three color channels using a nominal 6 MV linear accelerator. A 48-bit transmission scanner and advanced multichannel analysis method were utilized to derive dose measurements. Samples of the solid radiochromic polymer PRESAGE(®), 60 mm diameter and 100 mm height, were analyzed with a parallel beam optical CT scanner. Each dosimetry system was used to measure the dose as a function of radial distance from a Co-60 HDR source, with results compared to Monte Carlo TG-43 model data. Each system was then used to measure the dose distribution along one or more lines through typical clinical dose distributions for cervix brachytherapy, with results compared to treatment planning system (TPS) calculations. Purpose-designed test objects constructed of Solid Water and held within a full-scatter water tank were utilized. All three dosimetry systems reproduced the general shape of the isolated source radial dose function and the TPS dose distribution. However, the dynamic range of EBT3 exceeded those of doped optical fibers and PRESAGE(®), and the latter two suffered from unacceptable noise and artifact. For the experimental conditions used in this study, the useful range from an isolated HDR source was 5-40 mm for

  1. In vivo dosimetry of high-dose-rate brachytherapy: Study on 61 head-and-neck cancer patients using radiophotoluminescence glass dosimeter

    International Nuclear Information System (INIS)

    Nose, Takayuki; Koizumi, Masahiko; Yoshida, Ken; Nishiyama, Kinji; Sasaki, Junichi; Ohnishi, Takeshi; Peiffert, Didier

    2005-01-01

    Purpose: The largest in vivo dosimetry study for interstitial brachytherapy yet examined was performed using new radiophotoluminescence glass dosimeters (RPLGDs). Based on the results, a dose prescription technique achieving high reproducibility and eliminating large hyperdose sleeves was studied. Methods and materials: For 61 head-and-neck cancer patients who underwent high-dose-rate interstitial brachytherapy, new RPLGDs were used for an in vivo study. The Paris System was used for implant. An arbitrary isodose surface was selected for dose prescription. Locations of 83 dosimeters were categorized as on target (n = 52) or on nontarget organ (n = 31) and were also scaled according to % basal dose isodose surface (% BDIS). Compatibility (measured dose/calculated dose) was analyzed according to location. The hyperdose sleeve was assessed in terms of prescription surface expressed in % BDIS. Results: The spread of compatibilities was larger for on nontarget organ (1.06 ± 0.32) than for on target (0.87 ± 0.17, p = 0.01). Within on target RPLGDs, compatibility on 77% and < 95% BDIS for reproducibility and elimination of excessive hyperdose sleeve. For organs at risk, radioprotection should be considered even when calculated dose seems sufficiently low. Further development of planning software is necessary to prevent overestimation

  2. Inverse Planned High-Dose-Rate Brachytherapy for Locoregionally Advanced Cervical Cancer: 4-Year Outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Tinkle, Christopher L.; Weinberg, Vivian [Department of Radiation Oncology, University of California, San Francisco, California (United States); Chen, Lee-May [Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California (United States); Littell, Ramey [Gynecologic Oncology, The Permanente Medical Group, San Francisco, California (United States); Cunha, J. Adam M.; Sethi, Rajni A. [Department of Radiation Oncology, University of California, San Francisco, California (United States); Chan, John K. [Gynecologic Oncology, California Pacific Medical Center, San Francisco, California (United States); Hsu, I-Chow, E-mail: ichow.hsu@ucsf.edu [Department of Radiation Oncology, University of California, San Francisco, California (United States)

    2015-08-01

    Purpose: Evaluate the efficacy and toxicity of image guided brachytherapy using inverse planning simulated annealing (IPSA) high-dose-rate brachytherapy (HDRB) boost for locoregionally advanced cervical cancer. Methods and Materials: From December 2003 through September 2009, 111 patients with primary cervical cancer were treated definitively with IPSA-planned HDRB boost (28 Gy in 4 fractions) after external radiation at our institution. We performed a retrospective review of our experience using image guided brachytherapy. Of the patients, 70% had a tumor size >4 cm, 38% had regional nodal disease, and 15% had clinically evident distant metastasis, including nonregional nodal disease, at the time of diagnosis. Surgical staging involving pelvic lymph node dissection was performed in 15% of patients, and 93% received concurrent cisplatin-based chemotherapy. Toxicities are reported according to the Common Terminology Criteria for Adverse Events version 4.0 guidelines. Results: With a median follow-up time of 42 months (range, 3-84 months), no acute or late toxicities of grade 4 or higher were observed, and grade 3 toxicities (both acute and late) developed in 8 patients (1 constitutional, 1 hematologic, 2 genitourinary, 4 gastrointestinal). The 4-year Kaplan-Meier estimate of late grade 3 toxicity was 8%. Local recurrence developed in 5 patients (4 to 9 months after HDRB), regional recurrence in 3 (6, 16, and 72 months after HDRB), and locoregional recurrence in 1 (4 months after HDR boost). The 4-year estimates of local, locoregional, and distant control of disease were 94.0%, 91.9%, and 69.1%, respectively. The overall and disease-free survival rates at 4 years were 64.3% (95% confidence interval [CI] of 54%-73%) and 61.0% (95% CI, 51%-70%), respectively. Conclusions: Definitive radiation by use of inverse planned HDRB boost for locoregionally advanced cervical cancer is well tolerated and achieves excellent local control of disease. However, overall

  3. Assessing patient characteristics and radiation-induced non-targeted effects in vivo for high dose-rate (HDR) brachytherapy.

    Science.gov (United States)

    Pinho, Christine; Timotin, Emilia; Wong, Raimond; Sur, Ranjan K; Hayward, Joseph E; Farrell, Thomas J; Seymour, Colin; Mothersill, Carmel

    2015-01-01

    To test whether blood, urine, and tissue based colony-forming assays are a useful clinical detection tool for assessing fractionated treatment responses and non-targeted radiation effects in bystander cells. To assess patients' responses to radiation treatments, blood serum, urine, and an esophagus explant-based in vivo colony-forming assay were used from oesophageal carcinoma patients. These patients underwent three fractions of high dose rate (HDR) intraluminal brachytherapy (ILBT). Human keratinocyte reporters exposed to blood sera taken after the third fraction of brachytherapy had a significant increase in cloning efficiency compared to baseline samples (p fractions for the blood sera data only. Patient characteristics such as gender had no statistically significant effect (p > 0.05). Large variability was observed among the patients' tissue samples, these colony-forming assays showed no significant changes throughout fractionated brachytherapy (p > 0.05). Large inter-patient variability was found in the urine and tissue based assays, so these techniques were discontinued. However, the simple blood-based assay had much less variability. This technique may have future applications as a biological dosimeter to predict treatment outcome and assess non-targeted radiation effects.

  4. Interaction of 2-Gy Equivalent Dose and Margin Status in Perioperative High-Dose-Rate Brachytherapy

    International Nuclear Information System (INIS)

    Martinez-Monge, Rafael; Cambeiro, Mauricio; Moreno, Marta; Gaztanaga, Miren; San Julian, Mikel; Alcalde, Juan; Jurado, Matias

    2011-01-01

    Purpose: To determine patient, tumor, and treatment factors predictive of local control (LC) in a series of patients treated with either perioperative high-dose-rate brachytherapy (PHDRB) alone (Group 1) or with PHDRB combined with external-beam radiotherapy (EBRT) (Group 2). Patient and Methods: Patients (n = 312) enrolled in several PHDRB prospective Phase I-II studies conducted at the Clinica Universidad de Navarra were analyzed. Treatment with PHDRB alone, mainly because of prior irradiation, was used in 126 patients to total doses of 32 Gy/8 b.i.d. or 40 Gy/10 b.i.d. treatments after R0 or R1 resections. Treatment with PHDRB plus EBRT was used in 186 patients to total doses of 16 Gy/4 b.i.d. or 24 Gy/6 b.i.d. treatments after R0 or R1 resections along with 45 Gy of EBRT with or without concomitant chemotherapy. Results: No dose-margin interaction was observed in Group 1 patients. In Group 2 patients there was a significant interaction between margin status and 2-Gy equivalent (Eq2Gy) dose (p = 0.002): (1) patients with negative margins had 9-year LC of 95.7% at Eq2Gy = 62.9Gy; (2) patients with close margins of >1 mm had 9-year LC of 92.4% at Eq2Gy = 72.2Gy, and (3) patients with positive/close <1-mm margins had 9-year LC of 68.0% at Eq2Gy = 72.2Gy. Conclusions: Two-gray equivalent doses ≥70 Gy may compensate the effect of close margins ≥1 mm but do not counterbalance the detrimental effect of unfavorable (positive/close <1 mm) resection margins. No dose-margin interaction is observed in patients treated at lower Eq2Gy doses ≤50 Gy with PHDRB alone.

  5. On the use of multi-dimensional scaling and electromagnetic tracking in high dose rate brachytherapy

    Science.gov (United States)

    Götz, Th I.; Ermer, M.; Salas-González, D.; Kellermeier, M.; Strnad, V.; Bert, Ch; Hensel, B.; Tomé, A. M.; Lang, E. W.

    2017-10-01

    High dose rate brachytherapy affords a frequent reassurance of the precise dwell positions of the radiation source. The current investigation proposes a multi-dimensional scaling transformation of both data sets to estimate dwell positions without any external reference. Furthermore, the related distributions of dwell positions are characterized by uni—or bi—modal heavy—tailed distributions. The latter are well represented by α—stable distributions. The newly proposed data analysis provides dwell position deviations with high accuracy, and, furthermore, offers a convenient visualization of the actual shapes of the catheters which guide the radiation source during the treatment.

  6. Dosimetric Coverage of the Prostate, Normal Tissue Sparing, and Acute Toxicity with High-Dose-Rate Brachytherapy for Large Prostate Volumes

    Directory of Open Access Journals (Sweden)

    George Yang

    2015-06-01

    Full Text Available ABSTRACTPurposeTo evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes.Materials and MethodsOne hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL were treated with high-dose-rate (HDR brachytherapy ± intensity modulated radiation therapy (IMRT to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38% unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE version 4.ResultsMedian follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3% patients developed Grade 2 acute proctitis. No variables were significantly associated with Grade 2 acute proctitis. Seventeen of 102 (17% patients developed Grade 2 acute urinary retention. American Urological Association (AUA symptom score was the only variable significantly associated with Grade 2 acute urinary retention (p=0.04. There was no ≥ Grade 3 acute toxicity.ConclusionsDosimetric coverage of the prostate and normal tissue sparing were adequate in patients with prostate volumes >50 mL. Higher pre-treatment AUA symptom scores increased the relative risk of Grade 2 acute urinary retention. However, the overall incidence of acute toxicity was acceptable in patients with large prostate volumes.

  7. Dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with high-dose-rate brachytherapy for large prostate volumes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, George; Strom, Tobin J.; Shrinath, Kushagra; Mellon, Eric A.; Fernandez, Daniel C.; Biagioli, Matthew C. [Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL (United States); Wilder, Richard B., E-mail: mcbiagioli@yahoo.com [Cancer Treatment Centers of America, Newnan, GA (United States)

    2015-05-15

    Purpose: to evaluate dosimetric coverage of the prostate, normal tissue sparing, and acute toxicity with HDR brachytherapy for large prostate volumes. Materials and methods: one hundred and two prostate cancer patients with prostate volumes >50 mL (range: 5-29 mL) were treated with high-dose-rate (HDR) brachytherapy ± intensity modulated radiation therapy (IMRT) to 4,500 cGy in 25 daily fractions between 2009 and 2013. HDR brachytherapy monotherapy doses consisted of two 1,350-1,400 cGy fractions separated by 2-3 weeks, and HDR brachytherapy boost doses consisted of two 950-1,150 cGy fractions separated by 4 weeks. Twelve of 32 (38%) unfavorable intermediate risk, high risk, and very high risk patients received androgen deprivation therapy. Acute toxicity was graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 4. Results: median follow-up was 14 months. Dosimetric goals were achieved in over 90% of cases. Three of 102 (3%) patients developed Grade 2 acute proctitis. No variables were significantly associated with Grade 2 acute proctitis. Seventeen of 102 (17%) patients developed Grade 2 acute urinary retention. American Urological Association (AUA) symptom score was the only variable significantly associated with Grade 2 acute urinary retention (p-0.04). There was no ≥ Grade 3 acute toxicity. Conclusions: dosimetric coverage of the prostate and normal tissue sparing were adequate in patients with prostate volumes >50 mL. Higher pre-treatment AUA symptom scores increased the relative risk of Grade 2 acute urinary retention. However, the overall incidence of acute toxicity was acceptable in patients with large prostate volumes. (author)

  8. High dose-rate brachytherapy source localization: positional resolution using a diamond detector

    International Nuclear Information System (INIS)

    Nakano, T; Suchowerska, N; Bilek, M M; McKenzie, D R; Ng, N; Kron, T

    2003-01-01

    A potential real-time source position verification process for high dose-rate (HDR) brachytherapy treatment is described. This process is intended to provide immediate confirmation that a treatment is proceeding according to plan, so that corrective action can be taken if necessary. We show that three dosimeters are in principle sufficient and demonstrate the feasibility of the process using a diamond detector and an Ir-192 source. An error analysis including all identified sources of error shows that this detector is capable of locating the distance to the source to within 2 mm for distances up to 12 cm. This positional accuracy is less than the diameter of typical HDR catheters indicating that a diamond detector can be used to accurately determine the distance to the source. The uncertainty in the distance is found to increase with distance

  9. Treatment of localized prostate cancer using a combination of high dose rate lridium-192 brachytherapy and external beam irradiation: Initial Australian experience

    International Nuclear Information System (INIS)

    Stevens, M.J.; Stricker, P.D.; Brenner, P.C.; Kooner, R.; O'Neil, G.F.A.; Duval, P.J.; Jagavkar, R.S.; Cross, P.; Saalfeld, J.; Martland, J.

    2003-01-01

    Combination high dose rate brachytherapy (HDRB) and external beam radiation therapy is technically and clinically feasible as definitive treatment for localized prostate cancer. We report the first large Australian experience using this technique of radiation dose escalation in 82 patients with intermediate- and high-risk disease. With a median follow up of 3 years (156 weeks), complications were low and overall prostate-specific antigen progression-free survival was 91% using the American Society for Therapeutic Radiology and Oncology consensus definition. The delivery of hypofractionated radiation through the HDRB component shortens overall treatment time and is both biologically and logistically advantageous. As a radiation boost strategy, HDRB is easy to learn and could be introduced into most facilities with brachytherapy capability. Copyright (2003) Blackwell Science Pty Ltd

  10. A hybrid evolutionary algorithm for multi-objective anatomy-based dose optimization in high-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Lahanas, M; Baltas, D; Zamboglou, N

    2003-01-01

    Multiple objectives must be considered in anatomy-based dose optimization for high-dose-rate brachytherapy and a large number of parameters must be optimized to satisfy often competing objectives. For objectives expressed solely in terms of dose variances, deterministic gradient-based algorithms can be applied and a weighted sum approach is able to produce a representative set of non-dominated solutions. As the number of objectives increases, or non-convex objectives are used, local minima can be present and deterministic or stochastic algorithms such as simulated annealing either cannot be used or are not efficient. In this case we employ a modified hybrid version of the multi-objective optimization algorithm NSGA-II. This, in combination with the deterministic optimization algorithm, produces a representative sample of the Pareto set. This algorithm can be used with any kind of objectives, including non-convex, and does not require artificial importance factors. A representation of the trade-off surface can be obtained with more than 1000 non-dominated solutions in 2-5 min. An analysis of the solutions provides information on the possibilities available using these objectives. Simple decision making tools allow the selection of a solution that provides a best fit for the clinical goals. We show an example with a prostate implant and compare results obtained by variance and dose-volume histogram (DVH) based objectives

  11. External beam radiation therapy and a low-dose-rate brachytherapy boost without or with androgen deprivation therapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Tobin J.; Hutchinson, Sean Z.; Shrinath, Kushagra; Cruz, Alex A.; Figura, Nicholas B.; Nethers, Kevin; Biagioli, Matthew C.; Fernandez, Daniel C.; Heysek, Randy V.; Wilder, Richard B., E-mail: richard.wilder@moffitt.org [Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL (United States)

    2014-07-15

    Purpose: To assess outcomes with external beam radiation therapy (EBRT) and a low-dose-rate (LDR) brachytherapy boost without or with androgen deprivation therapy (ADT) for prostate cancer. Materials and Methods: From January 2001 through August 2011, 120 intermediate-risk or high-risk prostate cancer patients were treated with EBRT to a total dose of 4,500 cGy in 25 daily fractions and a palladium-103 LDR brachytherapy boost of 10,000 cGy (n = 90) or an iodine-125 LDR brachytherapy boost of 11,000 cGy (n = 30). ADT, consisting of a gonadotropin-releasing hormone agonist ± an anti-androgen, was administered to 29/92 (32%) intermediate-risk patients for a median duration of 4 months and 26/28 (93%) high-risk patients for a median duration of 28 months. Results: Median follow-up was 5.2 years (range, 1.1-12.8 years). There was no statistically-significant difference in biochemical disease-free survival (bDFS), distant metastasis-free survival (DMFS), or overall survival (OS) without or with ADT. Also, there was no statistically-significant difference in bDFS, DMFS, or OS with a palladium-103 vs. an iodine-125 LDR brachytherapy boost. Conclusions: There was no statistically-significant difference in outcomes with the addition of ADT, though the power of the current study was limited. The Radiation Therapy Oncology Group 0815 and 0924 phase III trials, which have accrual targets of more than 1,500 men, will help to clarify the role ADT in locally-advanced prostate cancer patients treated with EBRT and a brachytherapy boost. Palladium-103 and iodine-125 provide similar bDFS, DMFS, and OS. (author)

  12. A novel method for accurate needle-tip identification in trans-rectal ultrasound-based high-dose-rate prostate brachytherapy.

    Science.gov (United States)

    Zheng, Dandan; Todor, Dorin A

    2011-01-01

    In real-time trans-rectal ultrasound (TRUS)-based high-dose-rate prostate brachytherapy, the accurate identification of needle-tip position is critical for treatment planning and delivery. Currently, needle-tip identification on ultrasound images can be subject to large uncertainty and errors because of ultrasound image quality and imaging artifacts. To address this problem, we developed a method based on physical measurements with simple and practical implementation to improve the accuracy and robustness of needle-tip identification. Our method uses measurements of the residual needle length and an off-line pre-established coordinate transformation factor, to calculate the needle-tip position on the TRUS images. The transformation factor was established through a one-time systematic set of measurements of the probe and template holder positions, applicable to all patients. To compare the accuracy and robustness of the proposed method and the conventional method (ultrasound detection), based on the gold-standard X-ray fluoroscopy, extensive measurements were conducted in water and gel phantoms. In water phantom, our method showed an average tip-detection accuracy of 0.7 mm compared with 1.6 mm of the conventional method. In gel phantom (more realistic and tissue-like), our method maintained its level of accuracy while the uncertainty of the conventional method was 3.4mm on average with maximum values of over 10mm because of imaging artifacts. A novel method based on simple physical measurements was developed to accurately detect the needle-tip position for TRUS-based high-dose-rate prostate brachytherapy. The method demonstrated much improved accuracy and robustness over the conventional method. Copyright © 2011 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  13. Independent verification of the delivered dose in High-Dose Rate (HDR) brachytherapy

    International Nuclear Information System (INIS)

    Portillo, P.; Feld, D.; Kessler, J.

    2009-01-01

    An important aspect of a Quality Assurance program in Clinical Dosimetry is an independent verification of the dosimetric calculation done by the Treatment Planning System for each radiation treatment. The present paper is aimed at creating a spreadsheet for the verification of the dose recorded at a point of an implant with radioactive sources and HDR in gynecological injuries. An 192 Ir source automatic differed loading equipment, GammaMedplus model, Varian Medical System with HDR installed at the Angel H. Roffo Oncology Institute has been used. The planning system implemented for getting the dose distribution is the BraquiVision. The sources coordinates as well as those of the calculation point (Rectum) are entered into the Excel-devised verification program by assuming the existence of a point source in each one of the applicators' positions. Such calculation point has been selected as the rectum is an organ at risk, therefore determining the treatment planning. The dose verification is performed at points standing at a sources distance having at least twice the active length of such sources, so they may be regarded as point sources. Most of the sources used in HDR brachytherapy with 192 Ir have a 5 mm active length for all equipment brands. Consequently, the dose verification distance must be at least of 10 mm. (author)

  14. Perioperative fractionated high-dose rate brachytherapy for malignant bone and soft tissue tumors

    International Nuclear Information System (INIS)

    Koizumi, Masahiko; Inoue, Takehiro; Yamazaki, Hideya; Teshima, Teruki; Tanaka, Eiichi; Yoshida, Ken; Imai, Atsushi; Shiomi, Hiroya; Kagawa, Kazufumi; Araki, Nobuto; Kuratsu, Shigeyuki; Uchida, Atsumasa; Inoue, Toshihiko

    1999-01-01

    Purpose: To investigate the viability of perioperative fractionated HDR brachytherapy for malignant bone and soft tissue tumors, analyzing the influence of surgical margin. Methods and Materials: From July 1992 through May 1996, 16 lesions of 14 patients with malignant bone and soft tissue tumors (3 liposarcomas, 3 MFHs, 2 malignant schwannomas, 2 chordomas, 1 osteosarcoma, 1 leiomyosarcoma, 1 epithelioid sarcoma, and 1 synovial sarcoma) were treated at the Osaka University Hospital. The patients' ages ranged from 14 to 72 years (median: 39 years). Treatment sites were the pelvis in 6 lesions, the upper limbs in 5, the neck in 4, and a lower limb in 1. The resection margins were classified as intracapsular in 5 lesions, marginal in 5, and wide in 6. Postoperative fractionated HDR brachytherapy was started on the 4th-13th day after surgery (median: 6th day). The total dose was 40-50 Gy/7-10 fr/ 4-7 day (bid) at 5 or 10 mm from the source. Follow-up periods were between 19 and 46 months (median: 30 months). Results: Local control rates were 75% at 1 year and 48% in 2 years, and ultimate local control was achieved in 8 (50%) of 16 lesions. Of the 8 uncontrolled lesions, 5 (63%) had intracapsular (macroscopically positive) resection margins, and all the 8 controlled lesions (100%) had marginal (microscopically positive) or wide (negative) margins. Of the total, 3 patients died of both tumor and metastasis, 3 of metastasis alone, 1 of tumor alone, and 7 showed no evidence of disease. Peripheral nerve palsy was seen in one case after this procedure, but no infection or delayed wound healing caused by tubing or irradiation has occurred. Conclusion: Perioperative fractionated HDR brachytherapy is safe, well tolerated, and applicable to marginal or wide surgical margin cases

  15. Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer: long-term results

    International Nuclear Information System (INIS)

    Prada, Pedro J.; Anchuelo, Javier; Blanco, Ana Garcia; Paya, Gema; Cardenal, Juan; Acuña, Enrique; Ferri, Maria; Vazquez, Andres; Pacheco, Maite; Sanchez, Jesica

    2016-01-01

    Objectives: We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy. Methods and Materials: From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the 'Phoenix consensus'. Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition. Results: The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function. Conclusions: The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer. (author)

  16. Low-dose-rate brachytherapy for patients with transurethral resection before implantation in prostate cancer: long-term results

    Energy Technology Data Exchange (ETDEWEB)

    Prada, Pedro J.; Anchuelo, Javier; Blanco, Ana Garcia; Paya, Gema; Cardenal, Juan; Acuña, Enrique; Ferri, Maria [Department of Radiation Oncology, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria (Spain); Vazquez, Andres; Pacheco, Maite; Sanchez, Jesica [Department of Radiation Physics, Hospital Universitario Marqués de Valdecilla, Santander, Cantabria (Spain)

    2016-01-15

    Objectives: We analyzed the long-term oncologic outcome for patients with prostate cancer and transurethral resection who were treated using low-dose-rate (LDR) prostate brachytherapy. Methods and Materials: From January 2001 to December 2005, 57 consecutive patients were treated with clinically localized prostate cancer. No patients received external beam radiation. All of them underwent LDR prostate brachytherapy. Biochemical failure was defined according to the 'Phoenix consensus'. Patients were stratified as low and intermediate risk based on The Memorial Sloan Kettering group definition. Results: The median follow-up time for these 57 patients was 104 months. The overall survival according to Kaplan-Meier estimates was 88% (±6%) at 5 years and 77% (±6%) at 12 years. The 5 and 10 years for failure in tumour-free survival (TFS) was 96% and respectively (±2%), whereas for biochemical control was 94% and respectively (±3%) at 5 and 10 years, 98% (±1%) of patients being free of local recurrence. A patient reported incontinence after treatment (1.7%). The chronic genitourinary complains grade I were 7% and grade II, 10%. At six months 94% of patients reported no change in bowel function. Conclusions: The excellent long-term results and low morbidity presented, as well as the many advantages of prostate brachytherapy over other treatments, demonstrates that brachytherapy is an effective treatment for patients with transurethral resection and clinical organ-confined prostate cancer. (author)

  17. Acute genitourinary toxicity after high dose rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: Second analysis to determine the correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Katoh, Hiroyuki; Noda, Shin-ei; Ito, Kazuto; Yamamoto, Takumi; Kashiwagi, Bunzo; Nakano, Takashi

    2005-01-01

    Purpose: We have been treating localized prostate cancer with high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiation therapy (EBRT) at our institution. We recently reported the existence of a correlation between the severity of acute genitourinary (GU) toxicity and the urethral radiation dose in HDR brachytherapy by using different fractionation schema. The purpose of this study was to evaluate the role of the urethral dose in the development of acute GU toxicity more closely than in previous studies. For this purpose, we conducted an analysis of patients who had undergone HDR brachytherapy with a fixed fractionation schema combined with hypofractionated EBRT. Methods and Materials: Among the patients with localized prostate cancer who were treated by 192-iridium HDR brachytherapy combined with hypofractionated EBRT at Gunma University Hospital between August 2000 and November 2004, we analyzed 67 patients who were treated by HDR brachytherapy with the fractionation schema of 9 Gy x two times combined with hypofractionated EBRT. Hypofractionated EBRT was administered at a fraction dose of 3 Gy three times weekly, and a total dose of 51 Gy was delivered to the prostate gland and seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography-guided HDR brachytherapy. The planning target volume was defined as the prostate gland with a 5-mm margin all around, and the planning was conducted based on computed tomography images. The tumor stage was T1c in 13 patients, T2 in 31 patients, and T3 in 23 patients. The Gleason score was 2-6 in 12 patients, 7 in 34 patients, and 8-10 in 21 patients. Androgen ablation was performed in all the patients. The median follow-up duration was 11 months (range 3-24 months). The toxicities were graded based on the Radiation Therapy Oncology Group and the European Organization

  18. Phantom study of radiation doses outside the target volume brachytherapy versus external radiotherapy of early breast cancer

    International Nuclear Information System (INIS)

    Johansson, Bengt; Persson, Essie; Westman, Gunnar; Persliden, Jan

    2003-01-01

    Background and purpose: Brachytherapy is sometimes suggested as an adjuvant treatment after surgery of some tumours. When introducing this, it would be useful to have an estimate of the dose distribution to different body sites, both near and distant to target, comparing conventional external irradiation to brachytherapy. The aim of the present study was to determine radiation doses with both methods at different body sites, near and distant to target, in an experimental situation on an operated left sided breast cancer on a female Alderson phantom. Methods: Five external beam treatments with isocentric tangential fields were given by a linear accelerator. A specified dose of 1.0 Gy was given to the whole left sided breast volume. Five interstitial brachytherapy treatments were given to the upper, lateral quadrant of the left breast by a two plane, 10 needles implant. A dose of 1.0 Gy specified according to the Paris system was administered by a pulsed dose rate afterloading machine. Absorbed dose in different fixed dose points were measured by thermoluminescence dosimeters. Results: Both methods yielded an absorbed dose of the same size to the bone marrow and internal organs distant to target, 1.0-1.4% of the prescribed dose. There was a trend of lower doses to the lower half of the trunk and higher doses to the upper half of the trunk, respectively, by brachytherapy. A 90% reduction of absorbed dose with brachytherapy compared to external irradiation was found in the near-target region within 5 cm from target boundary where parts of the left lung and the heart are situated. If an adjuvant dose of 50 Gy is given with the external radiotherapy and brachytherapy, the absorbed dose in a part of the myocardium could be reduced from 31.8 to 2.1 Gy. Conclusions: Near target, brachytherapy yielded a considerably lower absorbed dose which is of special importance when considering radiation effects on the myocard and lungs. We could not demonstrate any difference of

  19. High dose rate brachytherapy for carcinoma of the cervix: risk factors for late rectal complications

    International Nuclear Information System (INIS)

    Uno, Takashi; Itami, Jun; Aruga, Moriyo; Kotaka, Kikuo; Fujimoto, Hajime; Minoura, Shigeki

    1996-01-01

    Purpose/Objective: To determine the incidence of late rectal complications in patients treated with high dose rate brachytherapy for FIGO stage IIB, IIIB carcinoma of the uterine cervix, and to evaluate the treatment factors associated with an increased probability of treatment complications. Materials and Methods: Records of 100 patients with FIGO IIB or IIIB cervical carcinoma treated with definitive irradiation using high dose rate intracavitary brachytherapy (HDR-ICR) between 1977 and 1994 were retrospectively reviewed. For each HDR-ICR session, 6 Gy isodose volume was reconstructed three dimensionally and the following three parameters were determined to represent this isodose volume, length (L); maximum longitudinal distance of 6 Gy isodose area in an oblique frontal plane containing the intrauterine applicator, width (W); maximum width of 6 Gy isodose area in the same plane, height (H); maximum dimension of 6 Gy isodose area perpendicular to the intrauterine applicator determined in the oblique sagittal plane. Point P/Q (2 cm ventral/dorsal from the proximal retention point of the intrauterine source) and point R/S (2 cm ventral/dorsal from the midpoint of the ovoid sources) were also defined retrospectively and HDR-ICR dose at these points were calculated. Statistical analyses were performed to determine the treatment factors predictive of late rectal complications. Results: The 5-year cumulative cause-specific disease-free survival rate was 50% for all, 74% for Stage IIB, and 38% for Stage IIIB, with a significant difference between two FIGO Stages (p=0.0004). Of patients treated for both stages, 30% and 36% had experienced moderate to severe (Grade 2-4) complications at 3 and 5 years, respectively. Average H value (p=0.013) and cumulative point S dose by HDR-ICR (p=0.020) were significantly correlated with the incidence of late rectal complications (Student's t-test), whereas these factors did not significantly affect the probability of pelvic control. No

  20. High-Dose-Rate Brachytherapy as a Monotherapy for Favorable-Risk Prostate Cancer: A Phase II Trial

    International Nuclear Information System (INIS)

    Barkati, Maroie; Williams, Scott G.; Foroudi, Farshad; Tai, Keen Hun; Chander, Sarat; Dyk, Sylvia van; See, Andrew; Duchesne, Gillian M.

    2012-01-01

    Purpose: There are multiple treatment options for favorable-risk prostate cancer. High-dose-rate (HDR) brachytherapy as a monotherapy is appealing, but its use is still investigational. A Phase II trial was undertaken to explore the value of such treatment in low-to-intermediate risk prostate cancer. Methods and Materials: This was a single-institution, prospective study. Eligible patients had low-risk prostate cancer features but also Gleason scores of 7 (51% of patients) and stage T2b to T2c cancer. Treatment with HDR brachytherapy with a single implant was administered over 2 days. One of four fractionation schedules was used in a dose escalation study design: 3 fractions of 10, 10.5, 11, or 11.5 Gy. Patients were assessed with the Common Terminology Criteria for Adverse Events version 2.0 for urinary toxicity, the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scoring schema for rectal toxicity, and the Expanded Prostate Cancer Index Composite (EPIC) questionnaire to measure patient-reported health-related quality of life. Biochemical failure was defined as a prostate-specific antigen (PSA) nadir plus 2 ng/ml. Results: Between 2003 and 2008, 79 patients were enrolled. With a median follow-up of 39.5 months, biochemical relapse occurred in 7 patients. Three- and 5-year actuarial biochemical control rates were 88.4% (95% confidence interval [CI], 78.0-96.2%) and 85.1% (95% CI, 72.5-94.5%), respectively. Acute grade 3 urinary toxicity was seen in only 1 patient. There was no instance of acute grade 3 rectal toxicity. Rates of late grade 3 rectal toxicity, dysuria, hematuria, urinary retention, and urinary incontinence were 0%, 10.3%, 1.3%, 9.0%, and 0%, respectively. No grade 4 or greater toxicity was recorded. Among the four (urinary, bowel, sexual, and hormonal) domains assessed with the EPIC questionnaire, only the sexual domain did not recover with time. Conclusions: HDR brachytherapy as a monotherapy for favorable

  1. High-Dose-Rate Brachytherapy as a Monotherapy for Favorable-Risk Prostate Cancer: A Phase II Trial

    Energy Technology Data Exchange (ETDEWEB)

    Barkati, Maroie [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Williams, Scott G., E-mail: scott.williams@petermac.org [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia); Foroudi, Farshad; Tai, Keen Hun; Chander, Sarat [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia); Dyk, Sylvia van [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); See, Andrew [Ballarat Austin Radiation Oncology Centre, Ballarat (Australia); Duchesne, Gillian M. [Division of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne (Australia); Department of Pathology, University of Melbourne, Melbourne (Australia)

    2012-04-01

    Purpose: There are multiple treatment options for favorable-risk prostate cancer. High-dose-rate (HDR) brachytherapy as a monotherapy is appealing, but its use is still investigational. A Phase II trial was undertaken to explore the value of such treatment in low-to-intermediate risk prostate cancer. Methods and Materials: This was a single-institution, prospective study. Eligible patients had low-risk prostate cancer features but also Gleason scores of 7 (51% of patients) and stage T2b to T2c cancer. Treatment with HDR brachytherapy with a single implant was administered over 2 days. One of four fractionation schedules was used in a dose escalation study design: 3 fractions of 10, 10.5, 11, or 11.5 Gy. Patients were assessed with the Common Terminology Criteria for Adverse Events version 2.0 for urinary toxicity, the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scoring schema for rectal toxicity, and the Expanded Prostate Cancer Index Composite (EPIC) questionnaire to measure patient-reported health-related quality of life. Biochemical failure was defined as a prostate-specific antigen (PSA) nadir plus 2 ng/ml. Results: Between 2003 and 2008, 79 patients were enrolled. With a median follow-up of 39.5 months, biochemical relapse occurred in 7 patients. Three- and 5-year actuarial biochemical control rates were 88.4% (95% confidence interval [CI], 78.0-96.2%) and 85.1% (95% CI, 72.5-94.5%), respectively. Acute grade 3 urinary toxicity was seen in only 1 patient. There was no instance of acute grade 3 rectal toxicity. Rates of late grade 3 rectal toxicity, dysuria, hematuria, urinary retention, and urinary incontinence were 0%, 10.3%, 1.3%, 9.0%, and 0%, respectively. No grade 4 or greater toxicity was recorded. Among the four (urinary, bowel, sexual, and hormonal) domains assessed with the EPIC questionnaire, only the sexual domain did not recover with time. Conclusions: HDR brachytherapy as a monotherapy for favorable

  2. American brachytherapy society (ABS) guidelines for brachytherapy of esophageal cancer

    International Nuclear Information System (INIS)

    Nag, Subir; Gaspar, Laurie; Herskovic, Arnold; Mantravadi, Prasad; Speiser, Burton

    1996-01-01

    Introduction: There is wide variation in the indications, techniques, treatment regimens and dosimetry being used to treat cancer of the esophagus and no guidelines exist for optimal therapy. Methods: The Clinical Research Committee of the ABS met to formulate consensus guidelines for brachytherapy in esophageal cancer. Results: Good candidates for brachytherapy include patients with unifocal disease, with thoracic tumor 10 cm primary regional lymph adenopathy or tumor located in the gastro-esophageal junction or cervical esophagus. Contraindications include tracheo-esophageal fistula or stenosis that cannot be by-passed. The esophageal or nasogastric tube inserted should have a diameter of 6-10 mm whenever possible. If 5FU-based chemotherapy and 50 Gy external beam (EBRT) are used, it is suggested that the low dose rate brachytherapy (LDR) dose be 20 Gy at 0.4-1 Gy/hr, prescribed at 1 cm from the source. If high dose rate (HDR) is used, the dose recommended is 10 Gy in 2 weekly fractions of 5 Gy each, given after EBRT. Chemotherapy is not usually given concurrently with brachytherapy, and when it is, the brachytherapy dose is reduced. The length of esophagus treated by brachytherapy includes the post-EBRT involved area and a 1-2 cm margin proximally and distally. Supportive care, given during EBRT includes an antifungal agent (e.g., diflucan) and carafate. Gradual dilatation of the esophagus is required post-treatment for esophageal strictures. Conclusion: Guidelines were developed for brachytherapy in esophageal cancer. As more clinical data becomes available, these guidelines will be updated by the ABS

  3. Automated calculation of point A coordinates for CT-based high-dose-rate brachytherapy of cervical cancer

    Directory of Open Access Journals (Sweden)

    Hyejoo Kang

    2017-07-01

    Full Text Available Purpose: The goal is to develop a stand-alone application, which automatically and consistently computes the coordinates of the dose calculation point recommended by the American Brachytherapy Society (i.e., point A based solely on the implanted applicator geometry for cervical cancer brachytherapy. Material and methods: The application calculates point A coordinates from the source dwell geometries in the computed tomography (CT scans, and outputs the 3D coordinates in the left and right directions. The algorithm was tested on 34 CT scans of 7 patients treated with high-dose-rate (HDR brachytherapy using tandem and ovoid applicators. A single experienced user retrospectively and manually inserted point A into each CT scan, whose coordinates were used as the “gold standard” for all comparisons. The gold standard was subtracted from the automatically calculated points, a second manual placement by the same experienced user, and the clinically used point coordinates inserted by multiple planners. Coordinate differences and corresponding variances were compared using nonparametric tests. Results: Automatically calculated, manually placed, and clinically used points agree with the gold standard to < 1 mm, 1 mm, 2 mm, respectively. When compared to the gold standard, the average and standard deviation of the 3D coordinate differences were 0.35 ± 0.14 mm from automatically calculated points, 0.38 ± 0.21 mm from the second manual placement, and 0.71 ± 0.44 mm from the clinically used point coordinates. Both the mean and standard deviations of the 3D coordinate differences were statistically significantly different from the gold standard, when point A was placed by multiple users (p < 0.05 but not when placed repeatedly by a single user or when calculated automatically. There were no statistical differences in doses, which agree to within 1-2% on average for all three groups. Conclusions: The study demonstrates that the automated algorithm

  4. Dosimetric characterization of the GammaClip™{sup 169}Yb low dose rate permanent implant brachytherapy source for the treatment of nonsmall cell lung cancer postwedge resection

    Energy Technology Data Exchange (ETDEWEB)

    Currier, Blake [Medical Physics, University of Massachusetts Lowell, 1 University Avenue, Lowell, Massachusetts 01854 (United States); Munro, John J. III [Source Production and Equipment Co., Inc., 113 Teal Street, St. Rose, Louisiana 70087 (United States); Medich, David C. [Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609 (United States)

    2013-08-15

    Purpose: A novel {sup 169}Yb low dose rate permanent implant brachytherapy source, the GammaClip™, was developed by Source Production and Equipment Co. (New Orleans, LA) which is designed similar to a surgical staple while delivering therapeutic radiation. In this report, the brachytherapy source was characterized in terms of “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud et al. [Med. Phys. 39, 2904–2929 (2012)] using the updated AAPM Task Group Report No. 43 formalism.Methods: Monte Carlo calculations were performed using Monte Carlo N-Particle 5, version 1.6 in water and air, the in-air photon spectrum filtered to remove photon energies below 10 keV in accordance with TG-43U1 recommendations and previously reviewed {sup 169}Yb energy cutoff levels [D. C. Medich, M. A. Tries, and J. M. Munro, “Monte Carlo characterization of an Ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty,” Med. Phys. 33, 163–172 (2006)]. TG-43U1 dosimetric data, including S{sub K}, D-dot (r,θ), Λ, g{sub L}(r), F(r, θ), φ{sub an}(r), and φ{sub an} were calculated along with their statistical uncertainties. Since the source is not axially symmetric, an additional set of calculations were performed to assess the resulting axial anisotropy.Results: The brachytherapy source's dose rate constant was calculated to be (1.22 ± 0.03) cGy h{sup −1} U{sup −1}. The uncertainty in the dose to water calculations, D-dot (r,θ), was determined to be 2.5%, dominated by the uncertainties in the cross sections. The anisotropy constant, φ{sub an}, was calculated to be 0.960 ± 0.011 and was obtained by integrating the anisotropy factor between 1 and 10 cm using a weighting factor proportional to r{sup −2}. The radial dose function was calculated at distances between 0.5 and 12 cm, with a maximum value of 1.20 at 5.15 ± 0.03 cm. Radial dose

  5. Online pretreatment verification of high-dose rate brachytherapy using an imaging panel

    Science.gov (United States)

    Fonseca, Gabriel P.; Podesta, Mark; Bellezzo, Murillo; Van den Bosch, Michiel R.; Lutgens, Ludy; Vanneste, Ben G. L.; Voncken, Robert; Van Limbergen, Evert J.; Reniers, Brigitte; Verhaegen, Frank

    2017-07-01

    Brachytherapy is employed to treat a wide variety of cancers. However, an accurate treatment verification method is currently not available. This study describes a pre-treatment verification system that uses an imaging panel (IP) to verify important aspects of the treatment plan. A detailed modelling of the IP was only possible with an extensive calibration performed using a robotic arm. Irradiations were performed with a high dose rate (HDR) 192Ir source within a water phantom. An empirical fit was applied to measure the distance between the source and the detector so 3D Cartesian coordinates of the dwell positions can be obtained using a single panel. The IP acquires 7.14 fps to verify the dwell times, dwell positions and air kerma strength (Sk). A gynecological applicator was used to create a treatment plan that was registered with a CT image of the water phantom used during the experiments for verification purposes. Errors (shifts, exchanged connections and wrong dwell times) were simulated to verify the proposed verification system. Cartesian source positions (panel measurement plane) have a standard deviation of about 0.02 cm. The measured distance between the source and the panel (z-coordinate) have a standard deviation up to 0.16 cm and maximum absolute error of  ≈0.6 cm if the signal is close to sensitive limit of the panel. The average response of the panel is very linear with Sk. Therefore, Sk measurements can be performed with relatively small errors. The measured dwell times show a maximum error of 0.2 s which is consistent with the acquisition rate of the panel. All simulated errors were clearly identified by the proposed system. The use of IPs is not common in brachytherapy, however, it provides considerable advantages. It was demonstrated that the IP can accurately measure Sk, dwell times and dwell positions.

  6. CT-guided high-dose-rate brachytherapy of unresectable hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Collettini, Federico; Schreiber, Nadja; Schnapauff, Dirk; Denecke, Timm; Hamm, Bernd; Gebauer, Bernhard; Wust, Peter; Schott, Eckart

    2015-01-01

    The purpose of the present study was to evaluate the clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) in patients with unresectable hepatocellular carcinoma (HCC). Over a 6-year period, 98 patients with 212 unresectable HCC underwent CT-HDRBT applying a 192 Ir source at our institution. Magnetic resonance imaging (MRI) follow-up was performed 6 weeks after the intervention and then every 3 months. The primary endpoint was local tumor control (LTC); secondary endpoints included progression-free survival (PFS) and overall survival (OS). Patients were available for MRI evaluation for a mean follow-up of 23.1 months (range 4-64 months; median 20 months). Mean tumor diameter was 5 cm (range 1.8-12 cm). Eighteen of 212 (8.5 %) tumors showed local progression after a mean LTC of 21.1 months. In all, 67 patients (68.4 %) experienced distant tumor progression. The mean PFS was 15.2 months. Forty-six patients died during the follow-up period. Median OS was 29.2 months. Actuarial 1-, 2-, and 3-year OS rates were 80, 62, and 46 %, respectively. CT-HDRBT is an effective therapy to attain local tumor control in patients with unresectable HCC. Prospective randomized studies comparing CT-HDRBT with the standard treatments like Radiofrequency ablation (RFA) and chemoembolization (TACE) are mandatory. (orig.) [de

  7. High dose rate versus low dose rate interstitial radiotherapy for carcinoma of the floor of mouth

    International Nuclear Information System (INIS)

    Inoue, Takehiro; Inoue, Toshihiko; Yamazaki, Hideya; Koizumi, Masahiko; Kagawa, Kazufumi; Yoshida, Ken; Shiomi, Hiroya; Imai, Atsushi; Shimizutani, Kimishige; Tanaka, Eichii; Nose, Takayuki; Teshima, Teruki; Furukawa, Souhei; Fuchihata, Hajime

    1998-01-01

    Purpose: Patients with cancer of the floor of mouth are treated with radiation because of functional and cosmetic reasons. We evaluate the treatment results of high dose rate (HDR) and low dose rate (LDR) interstitial radiation for cancer of the floor of mouth. Methods and Materials: From January 1980 through March 1996, 41 patients with cancer of the floor of mouth were treated with LDR interstitial radiation using 198 Au grains, and from April 1992 through March 1996 16 patients with HDR interstitial radiation. There were 26 T1 tumors, 30 T2 tumors, and 1 T3 tumor. For 21 patients treated with interstitial radiation alone, a total radiation dose of interstitial therapy was 60 Gy/10 fractions/6-7 days in HDR and 85 Gy within 1 week in LDR. For 36 patients treated with a combination therapy, a total dose of 30 to 40 Gy of external radiation and a total dose of 48 Gy/8 fractions/5-6 days in HDR or 65 Gy within 1 week in LDR were delivered. Results: Two- and 5-year local control rates of patients treated with HDR interstitial radiation were 94% and 94%, and those with LDR were 75% and 69%, respectively. Local control rate of patients treated with HDR brachytherapy was slightly higher than that with 198 Au grains (p = 0.113). For late complication, bone exposure or ulcer occurred in 6 of 16 (38%) patients treated with HDR and 13 of 41 (32%) patients treated with LDR. Conclusion: HDR fractionated interstitial brachytherapy can be an alternative to LDR brachytherapy for cancer of the floor of mouth and eliminate radiation exposure for the medical staff

  8. On the impact of improved dosimetric accuracy on head and neck high dose rate brachytherapy.

    Science.gov (United States)

    Peppa, Vasiliki; Pappas, Eleftherios; Major, Tibor; Takácsi-Nagy, Zoltán; Pantelis, Evaggelos; Papagiannis, Panagiotis

    2016-07-01

    To study the effect of finite patient dimensions and tissue heterogeneities in head and neck high dose rate brachytherapy. The current practice of TG-43 dosimetry was compared to patient specific dosimetry obtained using Monte Carlo simulation for a sample of 22 patient plans. The dose distributions were compared in terms of percentage dose differences as well as differences in dose volume histogram and radiobiological indices for the target and organs at risk (mandible, parotids, skin, and spinal cord). Noticeable percentage differences exist between TG-43 and patient specific dosimetry, mainly at low dose points. Expressed as fractions of the planning aim dose, percentage differences are within 2% with a general TG-43 overestimation except for the spine. These differences are consistent resulting in statistically significant differences of dose volume histogram and radiobiology indices. Absolute differences of these indices are however small to warrant clinical importance in terms of tumor control or complication probabilities. The introduction of dosimetry methods characterized by improved accuracy is a valuable advancement. It does not appear however to influence dose prescription or call for amendment of clinical recommendations for the mobile tongue, base of tongue, and floor of mouth patient cohort of this study. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Determination of the dose of traffic in HDR brachytherapy with ALANINE/R PE technique

    International Nuclear Information System (INIS)

    Guzman Calcina, C. S.; Chen, F.; Almeida, A. de; Baffa, O.

    2001-01-01

    It determines, experimentally, the dose of traffic in brachytherapy for High Dose Rate (HDR), using for the first-time the Electronic Paramagnetic Resonance (EPR) technique with alanine detectors. The value obtained is the published next to obtained using lithium fluoride thermoluminescent dosimeters [es

  10. High dose rate brachytherapy for the treatment of soft tissue sarcoma of the extremity

    International Nuclear Information System (INIS)

    Speight, J.L.; Streeter, O.E.; Chawla, S.; Menendez, L.E.

    1996-01-01

    Purpose: we examined the role of preoperative neoadjuvant chemoradiation and adjuvant high-dose rate brachytherapy on the management of prognostically unfavorable soft tissue sarcomas of the extremities. Our goal was to examine the effect of high dose rate interstitial brachytherapy (HDR IBT) on reducing the risk of local recurrence following limb-sparing resection, as well as shortening treatment duration. Materials and methods: eleven patients, ranging in age from 31 to 73 years old, with soft tissue sarcoma of the extremity were treated at USC/Norris Comprehensive Cancer Center during 1994 and 1995. All patients had biopsy proven soft tissue sarcoma, and all were suitable candidates for limb-sparing surgery. All lesions were greater than 5cm in size and were primarily high grade. Tumor histologies included malignant fibrous histiocytoma (45%), liposarcoma (18%) and leiomyosarcoma, synovial cell sarcoma and spindle cell sarcoma (36%). Sites of tumor origin were the lower extremity (55%), upper extremity (18%) and buttock (9%), 1 patient (9%) had lesions in both the upper and lower extremity. Patients received HDR IBT following combined chemotherapy and external beam irradiation (EBRT) and en bloc resection of the sarcoma. Neoadjuvant chemotherapy consisted of three to four cycles of either Ifosfamide/Mesna with or without Adriamycin, or Mesna, Adriamycin, Ifosfamide and Dacarbazine. One patient received Cis-platin in addition to Ifos/Adr. A minimum of two cycles of chemotherapy were administered prior to EBRT. Additional cycles of chemotherapy were completed concurrently with EBRT but prior to HDR IBT. Preoperative EBRT doses ranging from 40 to 59.4 Gy were given in daily fractions of 180 to 200cGy. Following en bloc resection, HDR IBT was administered using the Omnitron tm 2000 remote afterloading system. Doses ranging from 13 to 30 Gy were delivered to the surgical tumor bed at depths of 0.5mm to 0.75mm from the radioactive source. Results: median follow-up was

  11. Dose accumulation of multiple high dose rate prostate brachytherapy treatments in two commercially available image registration systems.

    Science.gov (United States)

    Poder, Joel; Yuen, Johnson; Howie, Andrew; Bece, Andrej; Bucci, Joseph

    2017-11-01

    The purpose of this study was to assess whether deformable image registration (DIR) is required for dose accumulation of multiple high dose rate prostate brachytherapy (HDRPBT) plans treated with the same catheter pattern on two different CT datasets. DIR was applied to 20 HDRPBT patients' planning CT images who received two treatment fractions on sequential days, on two different CT datasets, with the same implant. Quality of DIR in Velocity and MIM image registration systems was assessed by calculating the Dice Similarity Coefficient (DSC) and mean distance to agreement (MDA) for the prostate, urethra and rectum contours. Accumulated doses from each system were then calculated using the same DIR technique and dose volume histogram (DVH) parameters compared to manual addition with no DIR. The average DSC was found to be 0.83 (Velocity) and 0.84 (MIM), 0.80 (Velocity) and 0.80 (MIM), 0.80 (Velocity) and 0.81 (MIM), for the prostate, rectum and urethra contours, respectively. The average difference in calculated DVH parameters between the two systems using dose accumulation was less than 1%, and there was no statistically significant difference found between deformably accumulated doses in the two systems versus manual DVH addition with no DIR. Contour propagation using DIR in velocity and MIM was shown to be at least equivalent to inter-observer contouring variability on CT. The results also indicate that dose accumulation through manual addition of DVH parameters may be sufficient for HDRPBT treatments treated with the same catheter pattern on two different CT datasets. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  12. Spectroscopic output of {sup 125}I and {sup 103}Pd low dose rate brachytherapy sources

    Energy Technology Data Exchange (ETDEWEB)

    Usher-Moga, Jacqueline; Beach, Stephen M.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin--Madison, Madison, Wisconsin 53705 (United States); Global Physics Solutions, St. Joseph, Michigan 49085 (United States); Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

    2009-01-15

    The spectroscopic output of low dose rate (LDR) brachytherapy sources is dependent on the physical design and construction of the source. Characterization of the emitted photons from 12 {sup 125}I and 3 {sup 103}Pd LDR brachytherapy source models is presented. Photon spectra, both along the transverse bisector and at several polar angles, were measured in air with a high-purity reverse electrode germanium (REGe) detector. Measured spectra were corrected to in vacuo conditions via Monte Carlo and analytical methods. The tabulated and plotted spectroscopic data provide a more complete understanding of each source model's output characteristics than can be obtained with other measurement techniques. The variation in fluorescence yield of the {sup 125}I sources containing silver caused greater differences in the emitted spectra and average energies among these seed models than was observed for the {sup 103}Pd sources or the {sup 125}I sources that do not contain silver. Angular spectroscopic data further highlighted the effects of source construction unique to each model, as well as the asymmetric output of many seeds. These data demonstrate the need for the incorporation of such physically measured output characteristics in the Monte Carlo modeling process.

  13. Computed-tomography-guided high-dose-rate brachytherapy (CT-HDRBT) ablation of metastases adjacent to the liver hilum

    Energy Technology Data Exchange (ETDEWEB)

    Collettini, Federico, E-mail: federico.collettini@charite.de [Department of Radiology, Charité Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Singh, Anju [Department of Medical Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Schnapauff, Dirk [Department of Radiology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); Powerski, Maciej Janusz [Charité – Universitätsmedizin Berlin, Campus Benjamin Franklin, Hindenburgdamm 30, 12203 Berlin (Germany); Department of Radiation Oncology, Charité – Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin (Germany); and others

    2013-10-01

    Purpose: To evaluate technical feasibility and clinical outcome of computed tomography-guided high-dose-rate-brachytherapy (CT-HDRBT) ablation of metastases adjacent to the liver hilum. Materials and methods: Between November 2007 and May 2012, 32 consecutive patients with 34 metastases adjacent to the liver hilum (common bile duct or hepatic bifurcation ≤5 mm distance) were treated with CT-HDRBT. Treatment was performed by CT-guided applicator placement and high-dose-rate brachytherapy with an iridium-192 source. MRI follow-up was performed 6 weeks and every 3 months post intervention. The primary endpoint was local tumor control (LTC); secondary endpoints included time to progression (TTP) and overall survival (OS). Results: Patients were available for MRI evaluation for a mean follow-up time of 18.75 months (range: 3–56 months). Mean tumor diameter was 4.3 cm (range: 1.3–10.7 cm). One major complication was observed. Four (11.8%) local recurrences were observed after a local tumor control of 5, 8, 9 and 10 months, respectively. Twenty-two patients (68.75%) experienced a systemic tumor progression during the follow up period. Mean TTP was 12.9 months (range: 2–56 months). Nine patients died during the follow-up period. Median OS was 20.24 months. Conclusion: Minimally invasive CT-HDRBT is a safe and effective option also for unresectable liver metastases adjacent to the liver hilum that would have been untreatable by thermal ablation.

  14. Implementation of High-Dose-Rate Brachytherapy and Androgen Deprivation in Patients With Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lilleby, Wolfgang, E-mail: wolfgang.lilleby@ous-hf.no [Cancer Clinic, Oslo University Hospital, Norwegian Radiumhospital, Department of Radiotherapy and Oncology, Oslo (Norway); Tafjord, Gunnar; Raabe, Nils K. [Cancer Clinic, Oslo University Hospital, Norwegian Radiumhospital, Department of Radiotherapy and Oncology, Oslo (Norway)

    2012-07-01

    Purpose: To evaluate outcome (overall survival [OS], the actuarial 5-year cancer-specific survival [CSS], disease-free survival [DFS], biochemical failure-free survival [BFS]), complications and morbidity in patients treated with high-dose-rate brachytherapy (HDR-BT) boost and hormonal treatment with curative aims. Methods: Between 2004 and 2009, 275 prospectively followed pN0/N0M0 patients were included: 19 patients (7%) with T2, Gleason score 7 and prostate-specific antigen (PSA) <10 and 256 patients (93%) with T3 or Gleason score 8-10 or PSA >20 received multimodal treatment with conformal four-field radiotherapy (prostate/vesiculae 2 Gy Multiplication-Sign 25) combined with HDR-BT (iridium 192; prostate 10 Gy Multiplication-Sign 2) with long-term androgen deprivation therapy (ADT). Results: After a median observation time of 44.2 months (range, 10.4-90.5 months) 12 patients had relapsed clinically and/or biochemically and 10 patients were dead, of which 2 patients died from prostate cancer. Five-year estimates of BFS, CSS, DFS, and OS rates were 98.5%, 99.3%, 95.6%, and 96.3%, respectively. None of the patients with either Gleason score <8 or with intermediate risk profile had relapsed. The number of HDR-BT treatments was not related to outcome. Despite of age (median, 65.7 years; range, 45.7-77 years) and considerable pretreatment comorbidity in 39 of 275 patients, Genitourinary treatment-related morbidity was moderate with long-lasting Radiation Therapy Oncology Group Grade 2 voiding problems in 26 patients (9.5%) and occasionally mucous discharge in 20 patients (7%), none with Grade >2 for gastrointestinal at follow-up. Complications during implantations were related to pubic arch interference (4 patients) and lithotomy time, causing 2 patients to develop compartment syndrome. Conclusion: Despite still preliminary observations, our 5-year outcome estimates favor the implementation of high-dose-rate brachytherapy in high-risk patients combined with conformal

  15. Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the PTB and the BIPM

    International Nuclear Information System (INIS)

    Kessler, C.; Allisy-Roberts, P.J.; Selbach, H.J.

    2015-01-01

    An indirect comparison of the standards for reference air kerma rate (RAKR) for 192 Ir high dose rate (HDR) brachytherapy sources of the Physikalisch-Technische Bundesanstalt (PTB), Germany, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the PTB in September 2011. The comparison result, based on the calibration coefficients for a transfer standard and expressed as a ratio of the PTB and the BIPM standards for reference air kerma rate, is 1.0003 with a combined standard uncertainty of 0.0099. (authors)

  16. Patient effective dose from endovascular brachytherapy with {sup 192}Ir Sources

    Energy Technology Data Exchange (ETDEWEB)

    Perna, L.; Bianchi, C.; Novario, R.; Nicolini, G.; Tanzi, F.; Conte, L

    2002-07-01

    The growing use of endovascular brachytherapy has been accompanied by the publication of a large number of studies in several fields, but few studies on patient dose have been found in the literature. Moreover, these studies were carried out on the basis of Monte Carlo simulation. The aim of the present study was to estimate the effective dose to the patient undergoing endovascular brachytherapy treatment with {sup 192}Ir sources, by means of experimental measurements. Two standard treatments were taken into account: an endovascular brachytherapy of the coronary artery corresponding to the activity x time product of 184 GBq.min and an endovascular brachytherapy of the renal artery (898 GBq.min). Experimental assessment was accomplished by thermoluminescence dosemeters positioned in more than 300 measurement points in a properly adapted Rando phantom. A method has been developed to estimate the mean organ doses for all tissues and organs concerned in order to calculate the effective dose associated with intravascular brachytherapy. The normalised organ doses resulting from coronary treatment were 2.4x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for lung, 0.9x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for oesophagus and 0.48x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for bone marrow. During brachytherapy of the renal artery, the corresponding normalised doses were 4.2x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for colon, 7.8x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for stomach and 1.7x10{sup -2} mSv.GBq{sup -1}.min{sup -1} for liver. Coronary treatment involved an effective dose of 0.046 mSv.GBq{sup -1}.min{sup -1}, whereas the treatment of the renal artery resulted in an effective dose of 0.15 mSv.GBq{sup -1}.min{sup -1}; there were many similarities with data from former studies. Based on these results it can be concluded that the dose level of patients exposed during brachytherapy treatment is low. (author)

  17. Treatment of Recurrent Bronchial Carcinoma: The Role of High-Dose-Rate Endoluminal Brachytherapy

    International Nuclear Information System (INIS)

    Hauswald, Henrik; Stoiber, Eva; Rochet, Nathalie; Lindel, Katja; Grehn, Christian; Becker, Heinrich D.; Debus, Juergen; Harms, Wolfgang

    2010-01-01

    Purpose: This study's aim was to assess outcome and toxicity of high-dose-rate endoluminal brachytherapy (HDREB) for recurrent bronchial carcinoma. Methods and Materials: From 1987 to 2005, 41 patients were treated with HDREB for symptomatic recurrent bronchial carcinoma. All patients had previously undergone external beam radiotherapy (EBRT) with a median dose of 56 Gy (range, 30-70 Gy). The median HDREB dose applied was 15 Gy (range, 5-29 Gy). The median time interval between primary EBRT and reirradiation was 9 months (range, 2-54 months). Results: After a median follow-up of 6.7 months, the 6-, 12-, and 24-month overall survival rates were 58%, 18%, and 7%, respectively. The median overall survival time was 6.7 months. Local remission was achieved in 73% of patients (n = 30). A total of 24% of patients (n = 10) showed no response or progressive disease within 8 weeks after treatment. In 1 patient, treatment response was not documented. The 6-, 12-, and 24-month local control rates were 38%, 17%, and 3%, respectively. The median local progression-free survival time was 4 months (range, 1-23 months). Prognostic factors were a total dose of ≥15 Gy of HDREB (p = 0.029) and a Karnofsky performance score of ≥80% (p = 0.0012). The cause of death was locoregional progression in 27% of patients (n = 11), distant metastases in 24% of patients (n = 10), fatal hemorrhage in 15% of patients (n = 6), and other causes in 29% of patients (n = 12). None of the patients with locally controlled disease showed grade 3 or 4 late effects. Conclusions: Palliative treatment of symptomatic, locally recurrent bronchial carcinoma with HDREB can effectively relieve symptoms in the majority of patients while causing only few complications. Still, time to progression is short.

  18. Automated high-dose rate brachytherapy treatment planning for a single-channel vaginal cylinder applicator

    Science.gov (United States)

    Zhou, Yuhong; Klages, Peter; Tan, Jun; Chi, Yujie; Stojadinovic, Strahinja; Yang, Ming; Hrycushko, Brian; Medin, Paul; Pompos, Arnold; Jiang, Steve; Albuquerque, Kevin; Jia, Xun

    2017-06-01

    High dose rate (HDR) brachytherapy treatment planning is conventionally performed manually and/or with aids of preplanned templates. In general, the standard of care would be elevated by conducting an automated process to improve treatment planning efficiency, eliminate human error, and reduce plan quality variations. Thus, our group is developing AutoBrachy, an automated HDR brachytherapy planning suite of modules used to augment a clinical treatment planning system. This paper describes our proof-of-concept module for vaginal cylinder HDR planning that has been fully developed. After a patient CT scan is acquired, the cylinder applicator is automatically segmented using image-processing techniques. The target CTV is generated based on physician-specified treatment depth and length. Locations of the dose calculation point, apex point and vaginal surface point, as well as the central applicator channel coordinates, and the corresponding dwell positions are determined according to their geometric relationship with the applicator and written to a structure file. Dwell times are computed through iterative quadratic optimization techniques. The planning information is then transferred to the treatment planning system through a DICOM-RT interface. The entire process was tested for nine patients. The AutoBrachy cylindrical applicator module was able to generate treatment plans for these cases with clinical grade quality. Computation times varied between 1 and 3 min on an Intel Xeon CPU E3-1226 v3 processor. All geometric components in the automated treatment plans were generated accurately. The applicator channel tip positions agreed with the manually identified positions with submillimeter deviations and the channel orientations between the plans agreed within less than 1 degree. The automatically generated plans obtained clinically acceptable quality.

  19. Dose Distributions of an 192Ir Brachytherapy Source in Different Media

    Directory of Open Access Journals (Sweden)

    C. H. Wu

    2014-01-01

    Full Text Available This study used MCNPX code to investigate the brachytherapy 192Ir dose distributions in water, bone, and lung tissue and performed radiophotoluminescent glass dosimeter measurements to verify the obtained MCNPX results. The results showed that the dose-rate constant, radial dose function, and anisotropy function in water were highly consistent with data in the literature. However, the lung dose near the source would be overestimated by up to 12%, if the lung tissue is assumed to be water, and, hence, if a tumor is located in the lung, the tumor dose will be overestimated, if the material density is not taken into consideration. In contrast, the lung dose far from the source would be underestimated by up to 30%. Radial dose functions were found to depend not only on the phantom size but also on the material density. The phantom size affects the radial dose function in bone more than those in the other tissues. On the other hand, the anisotropy function in lung tissue was not dependent on the radial distance. Our simulation results could represent valid clinical reference data and be used to improve the accuracy of the doses delivered during brachytherapy applied to patients with lung cancer.

  20. Accelerated Partial Breast Irradiation With Low-Dose-Rate Interstitial Implant Brachytherapy After Wide Local Excision: 12-Year Outcomes From a Prospective Trial

    Energy Technology Data Exchange (ETDEWEB)

    Hattangadi, Jona A. [Harvard Radiation Oncology Program, Boston, MA (United States); Powell, Simon N. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); MacDonald, Shannon M.; Mauceri, Thomas; Ancukiewicz, Marek [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Freer, Phoebe [Department of Radiology, Massachusetts General Hospital, Boston, MA (United States); Lawenda, Brian [21st Century Oncology, Las Vegas, NV (United States); Alm El-Din, Mohamed A. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Clinical Oncology, Tanta University Hospital, Tanta (Egypt); Gadd, Michele A.; Smith, Barbara L. [Department of Surgical Oncology, Massachusetts General Hospital, Boston, MA (United States); Taghian, Alphonse G., E-mail: ataghian@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States)

    2012-07-01

    Purpose: To evaluate the long-term toxicity, cosmesis, and local control of accelerated partial breast irradiation with implant brachytherapy after wide local excision for Stage T1N0 breast cancer (BCa). Materials and Methods: Between 1997 and 2001, 50 patients with Stage T1N0M0 BCa were treated in a Phase I-II protocol using low-dose-rate accelerated partial breast irradiation with implant brachytherapy after wide local excision and lymph node surgery. The total dose was escalated in three groups: 50 Gy (n = 20), 55 Gy (n = 17), and 60 Gy (n = 13). Patient- and physician-assessed breast cosmesis, patient satisfaction, toxicity, mammographic abnormalities, repeat biopsies, and disease status were prospectively evaluated at each visit. Kendall's tau ({tau}{sub {beta}}) and logistic regression analyses were used to correlate outcomes with dose, implant volume, patient age, and systemic therapy. Results: The median follow-up period was 11.2 years (range, 4-14). The patient satisfaction rate was 67%, 67% reported good-excellent cosmesis, and 54% had moderate-severe fibrosis. Higher dose was correlated with worse cosmetic outcome ({tau}{sub {beta}} 0.6, p < .0001), lower patient satisfaction ({tau}{sub {beta}} 0.5, p < .001), and worse fibrosis ({tau}{sub {beta}} 0.4, p = .0024). Of the 50 patients, 35% had fat necrosis and 34% developed telangiectasias {>=}1 cm{sup 2}. Grade 3-4 late skin and subcutaneous toxicities were seen in 4 patients (9%) and 6 patients (13%), respectively, and both correlated with higher dose ({tau}{sub {beta}} 0.3-0.5, p {<=} .01). One patient had Grade 4 skin ulceration and fat necrosis requiring surgery. Mammographic abnormalities were seen in 32% of the patients, and 30% underwent repeat biopsy, of which 73% were benign. Six patients had ipsilateral breast recurrence: five elsewhere in the breast, and one at the implant site. One patient died of metastatic BCa after recurrence. The 12-year actuarial local control, recurrence

  1. Accelerated Partial Breast Irradiation With Low-Dose-Rate Interstitial Implant Brachytherapy After Wide Local Excision: 12-Year Outcomes From a Prospective Trial

    International Nuclear Information System (INIS)

    Hattangadi, Jona A.; Powell, Simon N.; MacDonald, Shannon M.; Mauceri, Thomas; Ancukiewicz, Marek; Freer, Phoebe; Lawenda, Brian; Alm El-Din, Mohamed A.; Gadd, Michele A.; Smith, Barbara L.; Taghian, Alphonse G.

    2012-01-01

    Purpose: To evaluate the long-term toxicity, cosmesis, and local control of accelerated partial breast irradiation with implant brachytherapy after wide local excision for Stage T1N0 breast cancer (BCa). Materials and Methods: Between 1997 and 2001, 50 patients with Stage T1N0M0 BCa were treated in a Phase I-II protocol using low-dose-rate accelerated partial breast irradiation with implant brachytherapy after wide local excision and lymph node surgery. The total dose was escalated in three groups: 50 Gy (n = 20), 55 Gy (n = 17), and 60 Gy (n = 13). Patient- and physician-assessed breast cosmesis, patient satisfaction, toxicity, mammographic abnormalities, repeat biopsies, and disease status were prospectively evaluated at each visit. Kendall’s tau (τ β ) and logistic regression analyses were used to correlate outcomes with dose, implant volume, patient age, and systemic therapy. Results: The median follow-up period was 11.2 years (range, 4–14). The patient satisfaction rate was 67%, 67% reported good-excellent cosmesis, and 54% had moderate-severe fibrosis. Higher dose was correlated with worse cosmetic outcome (τ β 0.6, p β 0.5, p β 0.4, p = .0024). Of the 50 patients, 35% had fat necrosis and 34% developed telangiectasias ≥1 cm 2 . Grade 3–4 late skin and subcutaneous toxicities were seen in 4 patients (9%) and 6 patients (13%), respectively, and both correlated with higher dose (τ β 0.3–0.5, p ≤ .01). One patient had Grade 4 skin ulceration and fat necrosis requiring surgery. Mammographic abnormalities were seen in 32% of the patients, and 30% underwent repeat biopsy, of which 73% were benign. Six patients had ipsilateral breast recurrence: five elsewhere in the breast, and one at the implant site. One patient died of metastatic BCa after recurrence. The 12-year actuarial local control, recurrence-free survival, and overall survival rate was 85% (95% confidence interval, 70–97%), 72% (95% confidence interval, 54–86%), and 87% (95

  2. Dosimetric Considerations to Determine the Optimal Technique for Localized Prostate Cancer Among External Photon, Proton, or Carbon-Ion Therapy and High-Dose-Rate or Low-Dose-Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Georg, Dietmar, E-mail: Dietmar.Georg@akhwien.at [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hopfgartner, Johannes [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Gòra, Joanna [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kuess, Peter [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Kragl, Gabriele [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Berger, Daniel [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Hegazy, Neamat [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Goldner, Gregor; Georg, Petra [Department of Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna/Allgemeines Krankenhaus der Stadt Wien, Vienna (Austria)

    2014-03-01

    Purpose: To assess the dosimetric differences among volumetric modulated arc therapy (VMAT), scanned proton therapy (intensity-modulated proton therapy, IMPT), scanned carbon-ion therapy (intensity-modulated carbon-ion therapy, IMIT), and low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy (BT) treatment of localized prostate cancer. Methods and Materials: Ten patients were considered for this planning study. For external beam radiation therapy (EBRT), planning target volume was created by adding a margin of 5 mm (lateral/anterior–posterior) and 8 mm (superior–inferior) to the clinical target volume. Bladder wall (BW), rectal wall (RW), femoral heads, urethra, and pelvic tissue were considered as organs at risk. For VMAT and IMPT, 78 Gy(relative biological effectiveness, RBE)/2 Gy were prescribed. The IMIT was based on 66 Gy(RBE)/20 fractions. The clinical target volume planning aims for HDR-BT ({sup 192}Ir) and LDR-BT ({sup 125}I) were D{sub 90%} ≥34 Gy in 8.5 Gy per fraction and D{sub 90%} ≥145 Gy. Both physical and RBE-weighted dose distributions for protons and carbon-ions were converted to dose distributions based on 2-Gy(IsoE) fractions. From these dose distributions various dose and dose–volume parameters were extracted. Results: Rectal wall exposure 30-70 Gy(IsoE) was reduced for IMIT, LDR-BT, and HDR-BT when compared with VMAT and IMPT. The high-dose region of the BW dose–volume histogram above 50 Gy(IsoE) of IMPT resembled the VMAT shape, whereas all other techniques showed a significantly lower high-dose region. For all 3 EBRT techniques similar urethra D{sub mean} around 74 Gy(IsoE) were obtained. The LDR-BT results were approximately 30 Gy(IsoE) higher, HDR-BT 10 Gy(IsoE) lower. Normal tissue and femoral head sparing was best with BT. Conclusion: Despite the different EBRT prescription and fractionation schemes, the high-dose regions of BW and RW expressed in Gy(IsoE) were on the same order of magnitude. Brachytherapy techniques

  3. Dosimetric Considerations to Determine the Optimal Technique for Localized Prostate Cancer Among External Photon, Proton, or Carbon-Ion Therapy and High-Dose-Rate or Low-Dose-Rate Brachytherapy

    International Nuclear Information System (INIS)

    Georg, Dietmar; Hopfgartner, Johannes; Gòra, Joanna; Kuess, Peter; Kragl, Gabriele; Berger, Daniel; Hegazy, Neamat; Goldner, Gregor; Georg, Petra

    2014-01-01

    Purpose: To assess the dosimetric differences among volumetric modulated arc therapy (VMAT), scanned proton therapy (intensity-modulated proton therapy, IMPT), scanned carbon-ion therapy (intensity-modulated carbon-ion therapy, IMIT), and low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy (BT) treatment of localized prostate cancer. Methods and Materials: Ten patients were considered for this planning study. For external beam radiation therapy (EBRT), planning target volume was created by adding a margin of 5 mm (lateral/anterior–posterior) and 8 mm (superior–inferior) to the clinical target volume. Bladder wall (BW), rectal wall (RW), femoral heads, urethra, and pelvic tissue were considered as organs at risk. For VMAT and IMPT, 78 Gy(relative biological effectiveness, RBE)/2 Gy were prescribed. The IMIT was based on 66 Gy(RBE)/20 fractions. The clinical target volume planning aims for HDR-BT ( 192 Ir) and LDR-BT ( 125 I) were D 90% ≥34 Gy in 8.5 Gy per fraction and D 90% ≥145 Gy. Both physical and RBE-weighted dose distributions for protons and carbon-ions were converted to dose distributions based on 2-Gy(IsoE) fractions. From these dose distributions various dose and dose–volume parameters were extracted. Results: Rectal wall exposure 30-70 Gy(IsoE) was reduced for IMIT, LDR-BT, and HDR-BT when compared with VMAT and IMPT. The high-dose region of the BW dose–volume histogram above 50 Gy(IsoE) of IMPT resembled the VMAT shape, whereas all other techniques showed a significantly lower high-dose region. For all 3 EBRT techniques similar urethra D mean around 74 Gy(IsoE) were obtained. The LDR-BT results were approximately 30 Gy(IsoE) higher, HDR-BT 10 Gy(IsoE) lower. Normal tissue and femoral head sparing was best with BT. Conclusion: Despite the different EBRT prescription and fractionation schemes, the high-dose regions of BW and RW expressed in Gy(IsoE) were on the same order of magnitude. Brachytherapy techniques were clearly superior in

  4. Verification of the calculation program for brachytherapy planning system of high dose rate (PLATO); Programa de verificacion del calculo para un sistema de planificacion de braquiterapia de alta tasa de dosis (PLATO)

    Energy Technology Data Exchange (ETDEWEB)

    Almansa, J.; Alaman, C.; Perez-Alija, J.; Herrero, C.; Real, R. del; Ososrio, J. L.

    2011-07-01

    In our treatments are performed brachytherapy high dose rate since 2007. The procedures performed include gynecological intracavitary treatment and interstitial. The treatments are performed with a source of Ir-192 activity between 5 and 10 Ci such that small variations in treatment times can cause damage to the patient. In addition the Royal Decree 1566/1998 on Quality Criteria in radiotherapy establishes the need to verify the monitor units or treatment time in radiotherapy and brachytherapy. All this justifies the existence of a redundant system for brachytherapy dose calculation that can reveal any abnormality is present.

  5. Deterministic calculations of radiation doses from brachytherapy seeds

    International Nuclear Information System (INIS)

    Reis, Sergio Carneiro dos; Vasconcelos, Vanderley de; Santos, Ana Maria Matildes dos

    2009-01-01

    Brachytherapy is used for treating certain types of cancer by inserting radioactive sources into tumours. CDTN/CNEN is developing brachytherapy seeds to be used mainly in prostate cancer treatment. Dose calculations play a very significant role in the characterization of the developed seeds. The current state-of-the-art of computation dosimetry relies on Monte Carlo methods using, for instance, MCNP codes. However, deterministic calculations have some advantages, as, for example, short computer time to find solutions. This paper presents a software developed to calculate doses in a two-dimensional space surrounding the seed, using a deterministic algorithm. The analysed seeds consist of capsules similar to IMC6711 (OncoSeed), that are commercially available. The exposure rates and absorbed doses are computed using the Sievert integral and the Meisberger third order polynomial, respectively. The software also allows the isodose visualization at the surface plan. The user can choose between four different radionuclides ( 192 Ir, 198 Au, 137 Cs and 60 Co). He also have to enter as input data: the exposure rate constant; the source activity; the active length of the source; the number of segments in which the source will be divided; the total source length; the source diameter; and the actual and effective source thickness. The computed results were benchmarked against results from literature and developed software will be used to support the characterization process of the source that is being developed at CDTN. The software was implemented using Borland Delphi in Windows environment and is an alternative to Monte Carlo based codes. (author)

  6. High-Dose-Rate Brachytherapy of a Single Implant With Two Fractions Combined With External Beam Radiotherapy for Hormone-Naive Prostate Cancer

    International Nuclear Information System (INIS)

    Sato, Morio; Mori, Takashi; Shirai, Shintaro; Kishi, Kazushi; Inagaki, Takeshi; Hara, Isao

    2008-01-01

    Purpose: To evaluate the preliminary outcomes of high-dose-rate (HDR) brachytherapy of a single implant with two fractions and external beam radiotherapy (EBRT) for hormone-naive prostate cancer. Methods and Materials: Between March 2000 and Sept 2003, a total of 53 patients with tumor Stage T1c-T3b N0 M0 prostate cancer were treated with HDR brachytherapy boost doses (7.5 Gy/fraction) and 50-Gy EBRT during a 5.5-week period. Median follow-up was 61 months. Patients were divided into groups with localized (T1c-T2b) and advanced disease (T3a-T3b). We used the American Society for Therapeutic Radiology and Oncology (ASTRO) definition for biochemical failure. According to recommendations of the Radiation Therapy Oncology Group-ASTRO Phoenix Consensus Conference, biochemical failure-free control rates (BF-FCRs) at 3 years were investigated as 2 years short of the median follow-up. Results: Between April 2000 and Sept 2007, Common Terminology Criteria for Adverse Events Version 2.0 late Grade 2 genitourinary and gastrointestinal toxicity rates were 0% and 3.8%, respectively. Erectile preservation was 25% at 5 years. Overall survival was 88.1% and cause-specific survival was 100%. At 3 years, ASTRO BF-FCRs of the localized and advanced groups were 100% and 42%, respectively (p = 0.001). Conclusions: The HDR brachytherapy of a single implant with two fractions plus EBRT is effective in treating patients with localized hormone-naive prostate cancer, with the least genitourinary and gastrointestinal toxicities; however, longer median BF-FCR follow-up is required to assess these findings

  7. MRI-based preplanning in low-dose-rate prostate brachytherapy

    International Nuclear Information System (INIS)

    Tanaka, Osamu; Hayashi, Shinya; Matsuo, Masayuki; Nakano, Masahiro; Kubota, Yasuaki; Maeda, Sunaho; Ohtakara, Kazuhiro; Deguchi, Takashi; Hoshi, Hiroaki

    2008-01-01

    Purpose: To compare the dosimetric results between MRI-based and TRUS-based preplanning in permanent prostate brachytherapy, and to estimate the accuracy of MRI-based preplanning by comparing with CT/MRI fusion-based postimplant dosimetry. Methods and materials: Twenty-one patients were entered in this prospective study with written informed consent. MRI-based and TRUS-based preplanning were performed. The seed and needle locations were identical according to MRI-based and TRUS-based preplanning. MRI-based and TRUS-based preplanning were compared using DVH-related parameters. Following brachytherapy, the accuracy of the MRI-based preplanning was evaluated by comparing it with CT/MRI fusion-based postimplant dosimetry. Results: Mean MRI-based prostate volume was slightly underestimated (0.73 cc in mean volume) in comparison to TRUS-based volume. There were no significant differences in the mean DVH-related parameters except with rectal V 100 (cc) between TRUS-based and MRI-based preplanning. Mean rectal V 100 (cc) was 0.74 cc in TRUS-based and 0.29 cc in MRI-based preplanning, respectively, and the values demonstrated a statistical difference. There was no statistical difference in mean rectal V 150 (cc), and rectal V 100 (cc) between MRI-based preplanning and CT/MRI fusion-based postimplant dosimetry. Conclusion: Prostate volume estimation and DVH-related parameters in MRI-based preplanning were almost identical to TRUS-based preplanning. From the results of CT/MRI fusion-based postimplant dosimetry, MRI-based preplanning was therefore found to be a reliable and useful modality, as well as being helpful for TRUS-based preplanning. MRI-based preplanning can more accurately predict postimplant rectal dose than TRUS-based preplanning

  8. COMP report: CPQR technical quality control guidelines for low-dose-rate permanent seed brachytherapy.

    Science.gov (United States)

    Beaulieu, Luc; Radford, Dee-Ann; Eduardo Villarreal-Barajas, J

    2018-03-14

    The Canadian Organization of Medical Physicists (COMP), in close partnership with the Canadian Partnership for Quality Radiotherapy (CPQR) has developed a series of Technical Quality Control (TQC) guidelines for radiation treatment equipment. These guidelines outline the performance objectives that equipment should meet in order to ensure an acceptable level of radiation treatment quality. The TQC guidelines have been rigorously reviewed and field tested in a variety of Canadian radiation treatment facilities. The development process enables rapid review and update to keep the guidelines current with changes in technology. This article contains detailed performance objectives and safety criteria for low-dose-rate (LDR) permanent seed brachytherapy. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  9. Sci-Thur PM – Brachytherapy 05: Surface Collimation Applied to Superficial Flap High Dose-Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Derek; Sabondjian, Eric; Lawrence, Kailin; Sankreacha, Raxa [University of Toronto, Carlo Fidani Peel Regional Cancer Center, Carlo Fidani Peel Regional Cancer Center, University of Toronto (Canada)

    2016-08-15

    Purpose: To apply surface collimation for superficial flap HDR skin brachytherapy utilizing common clinical resources and to demonstrate the potential for OAR dose reduction within a clinically relevant setting. Methods: Two phantom setups were used. 3 mm lead collimation was applied to a solid slab phantom to determine appropriate geometries relating to collimation and dwell activation. The same collimation was applied to the temple of an anthropomorphic head phantom to demonstrate lens dose reduction. Each setup was simulated and planned to deliver 400 cGy to a 3 cm circular target to 3 mm depth. The control and collimated irradiations were sequentially measured using calibrated radiochromic films. Results: Collimation for the slab phantom attenuated the dose beyond the collimator opening, decreasing the fall-off distances by half and reducing the area of healthy skin irradiated. Target coverage can be negatively impacted by a tight collimation margin, with the required margin approximated by the primary beam geometric penumbra. Surface collimation applied to the head phantom similarly attenuated the surrounding normal tissue dose while reducing the lens dose from 84 to 68 cGy. To ensure consistent setup between simulation and treatment, additional QA was performed including collimator markup, accounting for collimator placement uncertainties, standoff distance verification, and in vivo dosimetry. Conclusions: Surface collimation was shown to reduce normal tissue dose without compromising target coverage. Lens dose reduction was demonstrated on an anthropomorphic phantom within a clinical setting. Additional QA is proposed to ensure treatment fidelity.

  10. Sci-Thur PM – Brachytherapy 05: Surface Collimation Applied to Superficial Flap High Dose-Rate Brachytherapy

    International Nuclear Information System (INIS)

    Liu, Derek; Sabondjian, Eric; Lawrence, Kailin; Sankreacha, Raxa

    2016-01-01

    Purpose: To apply surface collimation for superficial flap HDR skin brachytherapy utilizing common clinical resources and to demonstrate the potential for OAR dose reduction within a clinically relevant setting. Methods: Two phantom setups were used. 3 mm lead collimation was applied to a solid slab phantom to determine appropriate geometries relating to collimation and dwell activation. The same collimation was applied to the temple of an anthropomorphic head phantom to demonstrate lens dose reduction. Each setup was simulated and planned to deliver 400 cGy to a 3 cm circular target to 3 mm depth. The control and collimated irradiations were sequentially measured using calibrated radiochromic films. Results: Collimation for the slab phantom attenuated the dose beyond the collimator opening, decreasing the fall-off distances by half and reducing the area of healthy skin irradiated. Target coverage can be negatively impacted by a tight collimation margin, with the required margin approximated by the primary beam geometric penumbra. Surface collimation applied to the head phantom similarly attenuated the surrounding normal tissue dose while reducing the lens dose from 84 to 68 cGy. To ensure consistent setup between simulation and treatment, additional QA was performed including collimator markup, accounting for collimator placement uncertainties, standoff distance verification, and in vivo dosimetry. Conclusions: Surface collimation was shown to reduce normal tissue dose without compromising target coverage. Lens dose reduction was demonstrated on an anthropomorphic phantom within a clinical setting. Additional QA is proposed to ensure treatment fidelity.

  11. SU-E-J-93: Parametrisation of Dose to the Mucosa of the Anterior Rectal Wall in Transrectal Ultrasound Guided High-Dose-Rate Brachytherapy of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Aitkenhead, A; Hamlett, L; Wood, D; Choudhury, A [The Christie Hospital NHS Foundation Trust, Manchester, Greater Manchester (United Kingdom)

    2014-06-01

    Purpose: In high-dose-rate (HDR) brachytherapy of the prostate, radiation is delivered from a number of radioactive sources which are inserted via catheter into the target volume. The rectal mucosa also receives dose during the treatment, which may lead to late toxicity effects. To allow possible links between rectal dose and toxicity to be investigated, suitable methods of parametrising the rectal dose are needed. Methods: During treatment of a series of 95 patients, anatomy and catheter locations were monitored by transrectal ultrasound, and target volume positions were contoured on the ultrasound scan by the therapist. The anterior rectal mucosal wall was identified by contouring the transrectal ultrasound balloon within the ultrasound scan. Source positions and dwell times, along with the dose delivered to the patient were computed using the Oncentra Prostate treatment planning system (TPS). Data for the series of patients were exported from the TPS in Dicom format, and a series of parametrisation methods were developed in a Matlab environment to assess the rectal dose. Results: Contours of the anterior rectal mucosa were voxelised within Matlab to allow the dose to the rectal mucosa to be analysed directly from the 3D dose grid. Dose parametrisations based on dose-surface (DSH) and dose-line (DLH) histograms were obtained. Both lateral and longitudinal extents of the mucosal dose were parametrised using dose-line histograms in the relevant directions. Conclusion: We have developed a series of dose parametrisations for quantifying the dose to the rectal mucosa during HDR prostate brachytherapy which are suitable for future studies investigating potential associations between mucosal dose and late toxicity effects. The geometry of the transrectal probe standardises the rectal anatomy, making this treatment technique particularly suited to studies of this nature.

  12. SU-E-J-93: Parametrisation of Dose to the Mucosa of the Anterior Rectal Wall in Transrectal Ultrasound Guided High-Dose-Rate Brachytherapy of the Prostate

    International Nuclear Information System (INIS)

    Aitkenhead, A; Hamlett, L; Wood, D; Choudhury, A

    2014-01-01

    Purpose: In high-dose-rate (HDR) brachytherapy of the prostate, radiation is delivered from a number of radioactive sources which are inserted via catheter into the target volume. The rectal mucosa also receives dose during the treatment, which may lead to late toxicity effects. To allow possible links between rectal dose and toxicity to be investigated, suitable methods of parametrising the rectal dose are needed. Methods: During treatment of a series of 95 patients, anatomy and catheter locations were monitored by transrectal ultrasound, and target volume positions were contoured on the ultrasound scan by the therapist. The anterior rectal mucosal wall was identified by contouring the transrectal ultrasound balloon within the ultrasound scan. Source positions and dwell times, along with the dose delivered to the patient were computed using the Oncentra Prostate treatment planning system (TPS). Data for the series of patients were exported from the TPS in Dicom format, and a series of parametrisation methods were developed in a Matlab environment to assess the rectal dose. Results: Contours of the anterior rectal mucosa were voxelised within Matlab to allow the dose to the rectal mucosa to be analysed directly from the 3D dose grid. Dose parametrisations based on dose-surface (DSH) and dose-line (DLH) histograms were obtained. Both lateral and longitudinal extents of the mucosal dose were parametrised using dose-line histograms in the relevant directions. Conclusion: We have developed a series of dose parametrisations for quantifying the dose to the rectal mucosa during HDR prostate brachytherapy which are suitable for future studies investigating potential associations between mucosal dose and late toxicity effects. The geometry of the transrectal probe standardises the rectal anatomy, making this treatment technique particularly suited to studies of this nature

  13. Performance evaluation and dose verification of the low dose rate permanent prostrate brachytherapy system at the korle-bu Teaching Hospital

    International Nuclear Information System (INIS)

    Asenso, Y.A.

    2015-07-01

    Low dose rate prostate brachytherapy equipment that is newly acquired or substantially upgraded requires acceptance testing before being put into clinical service as well as Quality control after installation and when in use. Thus, quality control tests typically are periodic repetitions, partial or full, of acceptance and commissioning tests. The ultrasound system is the most important equipment used in LDR prostate brachytherapy. The AAPM TG 128 provides a set of instructions for quality control testing of an ultrasound system with a specific focus on those tests applicable to image guidance during a prostate implant procedure. Following the AAPM TG 128 protocol and CIRS 045 brachytherapy QA phantom as well as other protocols, eight experiments were performed to evaluate the performance of the system. The overall average axial distance in the B and F columns were found to be 10.12 ± 0.1 mm and 10.10 ± 0.11 mm respectively deviating by approximately 1.2 % and 1.0 % respectively from a standard inter- target distance of 10 mm. Also the lateral distance measured along the rows 1, 2, 3 and 4 resulted in an average distance of 10.07 ± 0.06 mm along rows B4 – C4, deviating from the standard inter- target distance of 10 mm by approximately 0.07 mm or ± 0.7 %, that of B3 – D3 also was 20.01 ± 0.07, deviating from 20 mm standard inter- target distance by 0.01 mm or 0.05 %, targets along B2 – E2 recorded an average distance of 29.56 ± 0.33 mm deviating from 30 mm standard inter- target distance by approximately -0.44 mm or -1.47 % and the last which is B1 – F1 also recorded an average distance of 39.54 ± 0.38 mm deviating from 40 mm standard inter- target distance by approximately -0.46 mm or – 1.15 %. Volume measurement accuracy of the three standard volumes, 4 cm 3 , 9 cm 3 and 20 cm 3 produced average measurements of 3.97 ± 0.16 cm 3 , 8.86 ± 0.29 cm 3 and 20.11 ± 1.04 cm 3 resulting in approximate deviations of -0.75 %, -1.56 % and 0

  14. Pilot Quality Control Program for Brachytherapy of Low Dose Rate at the General Hospital of Mexico

    International Nuclear Information System (INIS)

    Alvarez R, J.T.; Tovar M, V.; Salinas, B.; Hernandez O, O.; Santillan B, L.; Molero M, C.; Montoya M, J.

    2004-01-01

    We describe the pilot quality control program for brachytherapy of low dose rate proposed to be used in the Radiotherapy Department at the General Hospital of Mexico. The program consists of three parts: a) development of calibration procedures, performed in terms of air-kerma strength for calibration of 137Cs and 192Ir brachytherapy sources, and for the calibration of well-type ionization chambers for 137Cs, b) performance of localisation and reconstruction techniques for radioactive sources with a Baltas' phantom. The results obtained for the media deviation , are in the optimum level, ± 0.5 mm < ± 1.0 mm; the confidence limit Δ, is in the emergency level, Δ=3.2 mm. c) verification of absorbed dose to water DW, given by the hospital. It consists on the characterisation of a TLD-100 powder dosimetry system at SSDL: The calibration curves for powder response (nC or nC/ mg) vs Dw and the control charts for the Harshaw 3500 reader were obtained. The statistical validation of the calibration curve by normality of the residuals and the lack of fit tests were realised. In the other hand, TLD's were irradiated in the hospital to a nominal Dw = 2 Gy with sources of 137Cs. The percent deviations Δ%, between the Dw imparted by the Hospital and the determined by SSDL, are 1.2% Δ≤ 6.5 % which are consistent with the expanded uncertainty U% for DW, 5.6 U% 10%

  15. SU-F-T-09: In Phantom Full-Implant Validation of Plastic Scintillation Detectors for in Vivo Dosimetry During Low Dose Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Therriault-Proulx, F; Bruno, T; Beddar, S [UT MD Anderson Cancer Center, Houston, TX (United States); Beaulieu, L [CHU de Quebec, Quebec, QC, CA (Canada)

    2016-06-15

    Purpose: To validate in a water phantom the use of plastic scintillation detectors to measure dose to the urethra and the rectal wall during a clinically realistic low dose rate (LDR) brachytherapy implant. Methods: A template was designed to replicate a clinically realistic LDR brachytherapy prostate implant inside a water phantom. Twenty-two catheters were inserted, including one mimicking the urethra and another the rectal wall. The needles inserted in the remaining 20 catheters were composed of thin-walled nylon tubes in which I-125 radioactive seeds (Air Kerma Strengths of (0.328±0.020)U) were abutted together with plastic spacers to replicate a typical loading. A plastic scintillation detector (PSD) with a 5-mm long × 1-mm diameter sensitive element was first placed inside the urethra and 1-second measurements were performed for 60s after each needle implant. Measurements were also performed at multiple positions along the urethra once all the needles were inserted. The procedure was then repeated with the PSD placed at the rectal wall. Results: Individual dose-rates ranging from 0.07µGy/s to 1.5µGy/s were measured after each needle implant. The average absolute relative differences were (6.2±3.6)% and (6.9±6.5)% to the values calculated with the TG-43 formalism, for the urethra and rectal wall respectively. These results are within expectations from the error uncertainty budget once accounting for uncertainties in seeds’ strength and positioning. Interestingly, the PSD allowed for unplanned error detection as the study was performed. Finally, the measured dose after the full implant at different positions along the mimicked organs at risk were in agreement with TG-43 values for all of the positions tested. Conclusion: Plastic scintillation detectors could be used as in vivo detectors for LDR brachytherapy as they would provide accurate dose information after each needle implant as well as along the organs at risk at the end of the implant.

  16. Pulse dose-rate brachytherapy and treatment of uterine cervix cancer: impact of a 3D or a 2D dosimetric support

    International Nuclear Information System (INIS)

    Tournat, H.; Chilles, A.; Charra-Brunaud, C.; Peiffert, D.; Ahmad, F.; Metayer, Y.

    2007-01-01

    Purpose To evaluate two dosimetric supports used in pulse dose rate brachytherapy (P.D.R.): coverage of target volumes, dose to organs at risk, residual tumor after surgery, survival. Patients and methods Twenty patients treated for uterine cervix tumor first by brachytherapy P.D.R. had a dosimetric CT-scan after implantation. For 9 patients, the treatment was planned from standard radiographies and then reported on CT-scan images. For 11 patients, it was directly planned from CT-scan. Six weeks after, 18 patients underwent surgery. Results With a median follow-up of 22 months, 2 year actuarial survival was 89%. Six patients developed grade II urinary or gynecological complications (LENT SOMA scale). No residual tumor was found for 12 patients (7 with a 3D treatment and 5 a 2 D treatment). Ninety-five percent of C.T.V.H.R. received 53 Gy (2D treatment) or 63 Gy (3D treatment). Two cm 3 of bladder wall received 63 Gy (2D) or 74 Gy (3D) although 2 cm 3 of rectal wall received 37 Gy (2D) and 35 Gy (3D). Conclusion Using CT-scan made us improve the coverage of the uterine cervix but increase the dose received by the bladder, without increasing the rate of histological remission after surgery. We should be prudent before changing our practice. (authors)

  17. Brachytherapy in head and neck cancers; Curietherapie des cancers de la sphere ORL

    Energy Technology Data Exchange (ETDEWEB)

    Mazeron, J.J.; Noel, G.; Simon, J.M.; Racadot, S.; Jauffret, E. [Groupe Hospitalier la Pitie-Salpetriere, Centre des Tumeurs, 75 - Paris (France)

    2003-02-01

    Experience accumulated over several decades with radiation of Head and Neck tumours by irradiation has demonstrated the need for a high tumour dose to achieve local control. With external beam irradiation alone, it is difficult to spare adjacent normal tissues, resulting in undesirable late effects on the salivary glands; mandible, and muscles of mastication. Interstitial implantation is ideally suited to deliver a high dose limited to the volume of the primary tumor, thus minimizing sequels. A large experience has been accumulated with low dose rate (LDR) brachytherapy in treatment of carcinoma of oral cavity, oropharynx, and nasopharynx. Recent analysis of large clinical series provided data indicating that modalities of low dose rate brachytherapy should be optimized in treating these tumors for increasing therapeutic ratio. Low dose rate brachytherapy is now challenged by high dose rate (HDR) brachytherapy and pulsed dose rate (PDR) brachytherapy. Preliminary results obtained with these two last modalities are discussed regarding to those of low dose rate brachytherapy. (authors)

  18. Evaluation of failure modes of computerized planning phase of interstitial implants with high dose rate brachytherapy using HFMEA

    International Nuclear Information System (INIS)

    Biazotto, Bruna; Tokarski, Marcio

    2014-01-01

    This paper evaluates the failure modes of the computerized planning step in interstitial implants with high dose rate brachytherapy. The prospective tool of risk management Health Care Failure Mode and Effects Analysis (HFMEA) was used. Twelve subprocesses were identified, and 33 failure modes of which 21 justified new safety actions, and 9 of them were intolerable risks. The method proved itself useful in identifying failure modes, but laborious and subjective in their assessment. The main risks were due to human factors, which require training and commitment of management to their mitigation. (author)

  19. Limb sparing surgery and boost with high dose rate interstitial brachytherapy in treatment of soft tissue sarcoma

    International Nuclear Information System (INIS)

    Koike, P.; Miziara, M.; Soares, C.; Fogaroli, R.; Baraldi, H.; Pellizoni, A.; Borba, G.

    2003-01-01

    Soft tissue sarcoma, a rare neoplasia with high aggressively, accounts for approximately 0,7% of the malignant tumors and occurs more often with youngest. Because of the potential risk of local recurrence, theoretically surgical resection, encompassing macroscopic tumor with a margin of macroscopically noninvolved tissue is the right way to perform, with a wide 'en bloc' resection, amputation, with bad functional results. The aim of conservative treatment is combined modality therapy as surgical resection and irradiation to obtain a local control rate as high as possible while preserving functional results. A retrospective review of 31 patients treated with high dose rate (HDR) Brachytherapy in the Radiotherapy Department Arnaldo Vieira de Carvalho Cancer Institute. Methods: Between April 1995 and August 1999, 31 patients who underwent a combine therapy; examined the results on multivariate analysis of conservative surgery and brachytherapy follow/or not by external beam radiation (EBRT). The 31 patients treated, 17 ( 54,8%) females and 14(45,2%) males have a median age of 48 years ( range,19 to 77 years). Most of the tumors was located in the lower limb (17/31 - 54,8%) . The other sites were the upper limb (10/31-32,3%), thoracic wall and abdomen (3/31-9,7%).Classification of the tumors, according to the International Union Against Cancer (UICC) staging was T1 5 patients (16%), T2 (24/31-77%). Median size of the tumors was 9,2cm ( ranged, 2,5 to 24cm). Most of the tumors being malignant fibrous histiocytomas (9/31-29%) and the histological grade II (14/31-45%). Twenty-two (71%) patients had intraoperative implants and the insertion of the radioactive source was delayed 24 to 120 hours. Eight patients (25,8%) had postoperative and received HDRB 45 to 60 days after the surgery . Guide needles were placed in the tumor bed, perpendicular to the scar, systematically in a single plane, the implant volume being defined by radiotherapist . A minimum safety margin of 2 cm

  20. Proposal of a high dose rate brachytherapy model for in vitro radiobiology studies

    International Nuclear Information System (INIS)

    Geraldo, Jony M.; Nogueira, Luciana B.; Andrade, Lidia M.; Trindade, Cassia; Furtado, Clascidia A.; Ladeira, Luiz Orlando

    2016-01-01

    The aim of this research was to develop an easy and reproducible approach for experimental HDR brachytherapy allowing in vitro irradiation studies based on clinical parameters. An acrylic platform was designed to attach T25 tissue culture flasks and multi-well tissue culture plates as well as kept the catheters in a fixed position during irradiation. CT images were taken and the irradiation was planned for 550cGy dose applied on adherent tumor cells. Dosimetric measurements were done and all relevant uncertainties were taken into account in order to figure out the correct dose range received by the cells. Tumor cells were irradiated two times over an interval of 24h between irradiations. Proof of concepts of this approach was carried out by biological effects analysis using a radioresistant human epidermoid carcinoma A431 cell line. Cellular proliferation and cell cycle phase were assessed by Trypan blue exclusion assay and DNA content analysis by flow cytometry, respectively. This approach allowed uniform dose distribution around the arrangement in all types of tissue culture plastics evaluated. Corrections due to uncertainties were managed. Regarding in vitro assays there was a significant (p<0.05) decreasing of cellular proliferation rate in irradiated cells. Moreover, increased percentage of cells arrested in G2/M phase (32.3 ± 1.5%) were observed for treated group compared with untreated cells. (author)

  1. Second salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer

    Directory of Open Access Journals (Sweden)

    Metha Maenhout

    2017-04-01

    Full Text Available Purpose : Salvage treatments for localized radiorecurrent prostate cancer can be performed safely when a focal and image guided approach is used. Due to the low toxicity, the opportunity exists to investigate a second salvage treatment when a second locally recurrent prostate cancer occurs. Here, we describe a second salvage treatment procedure of 4 patients. Material and methods : Four patients with a pathologically proven second local recurrence were treated in an outpatient magnetic resonance imaging (MRI-guided setting with a single fraction of 19 Gy focal high-dose-rate brachytherapy (HDR-BT. Delineation was performed using choline-PET-CT or a 68Ga-PSMA PET in combination with multiparametric 3 Tesla MRI in all four patients. Toxicity was measured using common toxicity criteria for adverse events (CTCAE version 4.0. Results : With a median follow-up of 12 months (range, 6-15, there were 2 patients with biochemical recurrence as defined by the Phoenix-definition. There were no patients with grade 3 or more toxicity. In all second salvage HDR-BT treatments, the constraints for rectum, bladder, and urethra were met. Median treatment volume (GTV was 4.8 cc (range, 1.9-6.6 cc. A median of 8 catheters (range, 6-9 were used, and the median dose to the treatment volume (GTV was a D95: 19.3 Gy (SD 15.5-19.4 Gy. Conclusions : Second focal salvage MRI-guided HDR-BT for a select group of patients with a second locally recurrent prostate cancer is feasible. There was no grade 3 or more acute toxicity for these four patients.

  2. Dose calculation in brachytherapy with microcomputers

    International Nuclear Information System (INIS)

    Elbern, A.W.

    1989-01-01

    The computer algorithms, that allow the calculation of brachytherapy doses and its graphic representation for implants, using programs developed for Pc microcomputers are presented. These algorithms allow to localized the sources in space, from their projection in radiographics images and trace isodose counter. (C.G.C.) [pt

  3. Cosmetic results in early stage breast cancer patients with high-dose brachytherapy after conservative surgery

    International Nuclear Information System (INIS)

    Torres, Felipe; Pineda, Beatriz E

    2004-01-01

    Purpose: to reveal cosmetic results in patients at early stages of low risk breast cancer treated with partial accelerated radiotherapy using high dose rate brachytherapy. Methods and materials: from March 2001 to July 2003,14 stages l and ll breast cancer patients were treated at the Colombian national cancer institute in Bogota with conservative surgery and radiotherapy upon the tumor bed (partial accelerated radiotherapy), using interstitial implants with iridium 192 (high dose rate brachytherapy) with a dose of 32 Gys, over 4 days, at 8 fractions twice a day. Results: with an average follow up of 17.7 months, good cosmetic results were found among 71.4 % of patients and excellent results among 14.3% of patients, furthermore none of the patients neither local nor regional or distant relapses. Conclusion: among patients who suffer from breast cancer at early stages, it showed is possible to apply partial accelerated radiotherapy upon the tumor bed with high doses over 4 days with good to excellent cosmetic results

  4. Evaluation of two intracavitary high-dose-rate brachytherapy devices for irradiating additional and irregularly shaped volumes of breast tissue

    International Nuclear Information System (INIS)

    Lu, Sharon M.; Scanderbeg, Daniel J.; Barna, Patrick; Yashar, William; Yashar, Catheryn

    2012-01-01

    The SAVI and Contura breast brachytherapy applicators represent 2 recent advancements in brachytherapy technology that have expanded the number of women eligible for accelerated partial breast irradiation in the treatment of early-stage breast cancer. Early clinical experience with these 2 single-entry, multichannel high-dose-rate brachytherapy devices confirms their ease of use and dosimetric versatility. However, current clinical guidelines for SAVI and Contura brachytherapy may result in a smaller or less optimal volume of treated tissue compared with traditional interstitial brachytherapy. This study evaluates the feasibility of using the SAVI and Contura to irradiate larger and irregularly shaped target volumes, approaching what is treatable with the interstitial technique. To investigate whether additional tissue can be treated, 17 patients treated with the SAVI and 3 with the Contura were selected. For each patient, the planning target volume (PTV) was modified to extend 1.1 cm, 1.3 cm, and 1.5 cm beyond the tumor bed cavity. To evaluate dose conformance to an irregularly shaped target volume, 9 patients treated with the SAVI and 3 with the Contura were selected from the original 20 patients. The following asymmetric PTV margin combinations were assessed for each patient: 1.5/0.3, 1.3/0.3, and 1.1/0.3 cm. For all patients, treatment planning was performed, adopting the National Surgical Adjuvant Breast and Bowel Project guidelines, and dosimetric comparisons were made. The 6–1 and 8–1 SAVI devices can theoretically treat a maximal tissue margin of 1.5 cm and an asymmetric PTV with margins ranging from 0.3 to 1.5 cm. The 10–1 SAVI and Contura can treat a maximal margin of 1.3 cm and 1.1 cm, respectively, and asymmetric PTV with margins ranging from 0.3–1.3 cm. Compared with the Contura, the SAVI demonstrated greater dosimetric flexibility. Risk of developing excessive hot spots increased with the size of the SAVI device. Both the SAVI and Contura

  5. Metal stent and endoluminal high-dose rate [sup 192]iridium brachytherapy in palliative treatment of malignant biliary tract obstruction. First experiences. Metallgeflecht-Endoprothese und intraluminare High-dose-rate-[sup 192]Iridium-Brachytherapie zur palliativen Behandlung maligner Gallengangsobstruktionen. Erste Erfahrungen

    Energy Technology Data Exchange (ETDEWEB)

    Pakisch, B; Stuecklschweiger, G; Poier, E; Leitner, H; Poschauko, J; Hackl, A [Universitaets-Klinik fuer Radiologie, Abt. fuer Strahlentherapie, Graz (Austria); Klein, G E; Lammer, J; Hausegger, K A [Universitaets-Klinik fuer Radiologie, Abt. fuer Spezielle Roentgendiagnostik und Digitale Bilddiagnostische Verfahren, Graz (Austria)

    1992-06-01

    Since December 1989, 9 patients with inoperable malignant biliary tract obstruction were treated palliatively by a combined modality treatment consisting of placement of a permanent biliary endoprosthesis followed by intraluminal high dose-rate [sup 192]Ir brachytherapy. A dose of 10 Gy was delivered in a hyperfractionated schedule at the point of reference in a distance of 7.5 mm of centre of the source. External small field radiotherapy (50.4 Gy, 1.8 Gy per day, 5 fractions per week) was also given in six cases (M/O, Karnofsky >60%). In 9/9 cases an unrestrained bile flow and an interruption of pruritus was achieved, in 78% (7/9) of cases the duration of palliation was as long as the survival time (median survival time 7.5 months). (orig.).

  6. SU-F-J-157: Effect of Contouring Uncertainty in Post Implant Dosimetry of Low-Dose-Rate Prostate Permanent Seed Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mashouf, S; Merino, T; Ravi, A; Morton, G; Song, W [Sunnybrook Health Sciences Center, Odette Cancer Centre, Toronto, ON (Canada); University of Toronto, Dept. of Radiation Oncology, Toronto, ON (Canada); Safigholi, H; Soliman, A [Sunnybrook Research Institute, Toronto, ON (Canada)

    2016-06-15

    Purpose: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. Methods: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55.8%, intermediate risk=39.5%, high risk=4.7%), who had received prostate seed brachytherapy, were imported into MIM Symphony treatment planning system. The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00 mm, ±2.00 mm, ±3.00 mm, ±4.00 mm and ±5.00 mm. The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: Significant changes were observed in the values of D90 and V100 as well as the number of suboptimal plans for expansion or contraction margins of only few millimeters. Evaluation of coverage based on D90 was found to be less sensitive to expansion errors compared to V100. D90 led to a lower number of implants incorrectly identified with insufficient coverage for expanded contours which increases the accuracy of post-implant QA using CT images compared to V100. Conclusion: In order to establish a successful post implant QA for LDR prostate seed brachytherapy, it is necessary to identify the low and high thresholds of important dose metrics of the target volume such as D90 and V100. Since these parameters are sensitive to target volume definition, accurate identification of prostate borders would help to improve accuracy and predictive value of the post-implant QA process. In this respect, use of imaging modalities such as MRI where prostate is well delineated should prove useful.

  7. SU-F-J-157: Effect of Contouring Uncertainty in Post Implant Dosimetry of Low-Dose-Rate Prostate Permanent Seed Brachytherapy

    International Nuclear Information System (INIS)

    Mashouf, S; Merino, T; Ravi, A; Morton, G; Song, W; Safigholi, H; Soliman, A

    2016-01-01

    Purpose: There is strong evidence relating post-implant dosimetry for low-dose-rate (LDR) prostate seed brachytherapy to local control rates. The delineation of the prostate on CT images, however, represents a challenge due to the lack of soft tissue contrast in order to identify the prostate borders. This study aims at quantifying the sensitivity of clinically relevant dosimetric parameters to uncertainty in the contouring of prostate. Methods: CT images, post-op plans and contours of a cohort of patients (n=43) (low risk=55.8%, intermediate risk=39.5%, high risk=4.7%), who had received prostate seed brachytherapy, were imported into MIM Symphony treatment planning system. The prostate contours in post-implant CT images were expanded/contracted uniformly for margins of ±1.00 mm, ±2.00 mm, ±3.00 mm, ±4.00 mm and ±5.00 mm. The values for V100 and D90 were extracted from Dose Volume Histograms for each contour and compared. Results: Significant changes were observed in the values of D90 and V100 as well as the number of suboptimal plans for expansion or contraction margins of only few millimeters. Evaluation of coverage based on D90 was found to be less sensitive to expansion errors compared to V100. D90 led to a lower number of implants incorrectly identified with insufficient coverage for expanded contours which increases the accuracy of post-implant QA using CT images compared to V100. Conclusion: In order to establish a successful post implant QA for LDR prostate seed brachytherapy, it is necessary to identify the low and high thresholds of important dose metrics of the target volume such as D90 and V100. Since these parameters are sensitive to target volume definition, accurate identification of prostate borders would help to improve accuracy and predictive value of the post-implant QA process. In this respect, use of imaging modalities such as MRI where prostate is well delineated should prove useful.

  8. Application of Multiobjective Genetic Algorithms in Anatomy Based Dose Optimization in Brachytherapy and its Comparation with Deterministic Algorithms

    National Research Council Canada - National Science Library

    Milickovic, Natasa

    2001-01-01

    In High Dose Rate (HDR) brachytherapy the conventional dose optimization algorithms consider the multiple objectives in the form of an aggregate function which combines individual objectives into a single utility value...

  9. A generic high-dose rate {sup 192}Ir brachytherapy source for evaluation of model-based dose calculations beyond the TG-43 formalism

    Energy Technology Data Exchange (ETDEWEB)

    Ballester, Facundo, E-mail: Facundo.Ballester@uv.es [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Carlsson Tedgren, Åsa [Department of Medical and Health Sciences (IMH), Radiation Physics, Faculty of Health Sciences, Linköping University, Linköping SE-581 85, Sweden and Department of Medical Physics, Karolinska University Hospital, Stockholm SE-171 76 (Sweden); Granero, Domingo [Department of Radiation Physics, ERESA, Hospital General Universitario, Valencia E-46014 (Spain); Haworth, Annette [Department of Physical Sciences, Peter MacCallum Cancer Centre and Royal Melbourne Institute of Technology, Melbourne, Victoria 3000 (Australia); Mourtada, Firas [Department of Radiation Oncology, Helen F. Graham Cancer Center, Christiana Care Health System, Newark, Delaware 19713 (United States); Fonseca, Gabriel Paiva [Instituto de Pesquisas Energéticas e Nucleares – IPEN-CNEN/SP, São Paulo 05508-000, Brazil and Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht 6201 BN (Netherlands); Zourari, Kyveli; Papagiannis, Panagiotis [Medical Physics Laboratory, Medical School, University of Athens, 75 MikrasAsias, Athens 115 27 (Greece); Rivard, Mark J. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts 02111 (United States); Siebert, Frank-André [Clinic of Radiotherapy, University Hospital of Schleswig-Holstein, Campus Kiel, Kiel 24105 (Germany); Sloboda, Ron S. [Department of Medical Physics, Cross Cancer Institute, Edmonton, Alberta T6G 1Z2, Canada and Department of Oncology, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); and others

    2015-06-15

    Purpose: In order to facilitate a smooth transition for brachytherapy dose calculations from the American Association of Physicists in Medicine (AAPM) Task Group No. 43 (TG-43) formalism to model-based dose calculation algorithms (MBDCAs), treatment planning systems (TPSs) using a MBDCA require a set of well-defined test case plans characterized by Monte Carlo (MC) methods. This also permits direct dose comparison to TG-43 reference data. Such test case plans should be made available for use in the software commissioning process performed by clinical end users. To this end, a hypothetical, generic high-dose rate (HDR) {sup 192}Ir source and a virtual water phantom were designed, which can be imported into a TPS. Methods: A hypothetical, generic HDR {sup 192}Ir source was designed based on commercially available sources as well as a virtual, cubic water phantom that can be imported into any TPS in DICOM format. The dose distribution of the generic {sup 192}Ir source when placed at the center of the cubic phantom, and away from the center under altered scatter conditions, was evaluated using two commercial MBDCAs [Oncentra{sup ®} Brachy with advanced collapsed-cone engine (ACE) and BrachyVision ACUROS{sup TM}]. Dose comparisons were performed using state-of-the-art MC codes for radiation transport, including ALGEBRA, BrachyDose, GEANT4, MCNP5, MCNP6, and PENELOPE2008. The methodologies adhered to recommendations in the AAPM TG-229 report on high-energy brachytherapy source dosimetry. TG-43 dosimetry parameters, an along-away dose-rate table, and primary and scatter separated (PSS) data were obtained. The virtual water phantom of (201){sup 3} voxels (1 mm sides) was used to evaluate the calculated dose distributions. Two test case plans involving a single position of the generic HDR {sup 192}Ir source in this phantom were prepared: (i) source centered in the phantom and (ii) source displaced 7 cm laterally from the center. Datasets were independently produced by

  10. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    Energy Technology Data Exchange (ETDEWEB)

    Brandao, Samia de Freitas, E-mail: samiabrandao@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Campos, Tarcisio Passos Ribeiro de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2013-06-15

    Objective: comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and methods: simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results: intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively, on the healthy tissue, on the balloon periphery and on the /{sub 1} and /{sub 2} tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h{sup -1}.p{sup -1}.s, respectively on the healthy tissue, on the target tumor and on the /{sub 1} and /{sub 2} infiltration zones. Conclusion: Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones. (author)

  11. Comparative dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for brain tumors

    Directory of Open Access Journals (Sweden)

    Samia de Freitas Brandao

    2013-07-01

    Full Text Available Objective Comparative analysis of dosimetry in intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT for treatment of brain tumors. Materials and Methods Simulations of intracavitary balloon catheter brachytherapy with I-125 and in Cf-252 brachytherapy combined with BNCT were performed with the MCNP5 code, modeling the treatment of a brain tumor on a voxel computational phantom representing a human head. Absorbed dose rates were converted into biologically weighted dose rates. Results Intracavitary balloon catheter brachytherapy with I-125 produced biologically weighted mean dose rates of 3.2E-11, 1.3E-10, 1.9E-11 and 6.9E-13 RBE.Gy.h-1.p-1.s, respectively, on the healthy tissue, on the balloon periphery and on the I 1 and I 2 tumor infiltration zones. On the other hand, Cf-252 brachytherapy combined with BNCT produced a biologically weighted mean dose rate of 5.2E-09, 2.3E-07, 8.7E-09 and 2.4E-09 RBE.Gy.h-1.p-1.s, respectively on the healthy tissue, on the target tumor and on the I 1 and I 2 infiltration zones. Conclusion Cf-252 brachytherapy combined with BNCT delivered a selective irradiation to the target tumor and to infiltration zones, while intracavitary balloon catheter brachytherapy with I-125 delivered negligible doses on the tumor infiltration zones.

  12. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    Science.gov (United States)

    Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Eng, Tony; Papanikolaou, Nikos

    2010-09-01

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent™ x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

  13. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos [Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, TX 78229 (United States); Cheng, Chih-Yao, E-mail: shic@uthscsa.ed [Radiation Oncology Department, Oklahoma University Health Science Center, Oklahoma, OK 73104 (United States)

    2010-09-21

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V{sub 100} reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as

  14. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source

    International Nuclear Information System (INIS)

    Shi Chengyu; Guo Bingqi; Eng, Tony; Papanikolaou, Nikos; Cheng, Chih-Yao

    2010-01-01

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent(TM) x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V 100 reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95

  15. High dose rate brachytherapy (HDRB) in prostate cancer - technique description and preliminary results

    International Nuclear Information System (INIS)

    Cordova Junior, Ardo Lotar; Salvajoli, Joao Victor; Pelizzon, Antonio CAssio Assis; Cecilio, Paulo Jose

    1998-01-01

    Describe the technique and preliminary results of high dose rate brachytherapy (HDRB) in localized prostate cancer. Subjects methods: Between March, 1997 and April, 1998, 26 patients were treated with external beam radiotherapy (45 to 50.4 Gy - 1.8 Gy per day) and implants (16 Gy in 2 days - twice a day). Median age was 68 years. The distribution by clinical stage was: 5 T1c, 9 T2a, 10 T2b and 2 T3a. Median initial PSA was 16 ng/ml. Results: With a median follow-up of 4 months, 85% of patients showed normal levels of PSA, with a median of 0.6 ng/ml, 60 to 90 days after treatment. Dysuria grades 1 and 2 and proctitis grade 1 were found in 11,3 and 5 patients, respectively. Conclusion: The method is safe, with acceptable early side effects. Longer follow-up is necessary before drawing any conclusions. (author)

  16. Efficacy of prophylactic single-dose therapy using fluoroquinolone for prostate brachytherapy

    International Nuclear Information System (INIS)

    Nomura, Takeo; Hirai, Kenichi; Yamasaki, Mutsushi; Inoue, Toru; Takahashi, Mika; Kawashima, Takayuki; Sato, Fuminori; Mimata, Hiromitsu

    2012-01-01

    There is little definitive evidence to guide the use of prophylactic antibiotics for prostate brachytherapy. The purpose of this study is to evaluate the incidence of postimplant infections in patients who receive antimicrobial prophylaxis with pazufloxacin (PZFX). A total of 84 patients who underwent prostate brachytherapy received a single intravenous dose of PZFX at 500 mg perioperatively for 1 day. No postimplant antibiotic medication was prescribed. Urinalysis, plasma white blood cell (WBC) count, and C reactive protein (CRP) levels were evaluated before the implantation, on the day after implantation, and on the 7th and 28th days after brachytherapy. None of the 84 patients (0.0%) developed a symptomatic urinary tract infection or had febrile infectious complications after brachytherapy. There were statistically significant elevations in the levels of erythrocytes, leukocytes, bacteria in urine, plasma WBC and CRP postoperatively, but these values did not exceed the normal range or were only slightly elevated on the day after brachytherapy (day 1) and on day 7. All laboratory examinations had returned to the normal range on day 28. Single-dose therapy with fluoroquinolone helps to prevent infections after prostate brachytherapy. (author)

  17. Dose-volume analysis for quality assurance of interstitial brachytherapy for breast cancer

    International Nuclear Information System (INIS)

    Vicini, Frank A.; Kestin, Larry L.; Edmundson, Gregory K.; Jaffray, David A.; Wong, John W.; Kini, Vijay R.; Chen, Peter Y.; Martinez, Alvaro A.

    1999-01-01

    Purpose/Objective: The use of brachytherapy in the management of breast cancer has increased significantly over the past several years. Unfortunately, few techniques have been developed to compare dosimetric quality and target volume coverage concurrently. We present a new method of implant evaluation that incorporates computed tomography-based three-dimensional (3D) dose-volume analysis with traditional measures of brachytherapy quality. Analyses performed in this fashion will be needed to ultimately assist in determining the efficacy of breast implants. Methods and Materials: Since March of 1993, brachytherapy has been used as the sole radiation modality after lumpectomy in selected protocol patients with early-stage breast cancer treated with breast-conserving therapy. Eight patients treated with high-dose-rate (HDR) brachytherapy who had surgical clips outlining the lumpectomy cavity and underwent computed tomography (CT) scanning after implant placement were selected for this study. For each patient, the postimplant CT dataset was transferred to a 3D treatment planning system. The lumpectomy cavity, target volume (lumpectomy cavity plus a 1-cm margin), and entire breast were outlined on each axial slice. Once all volumes were entered, the programmed HDR brachytherapy source positions and dwell times were imported into the 3D planning system. Using the tools provided by the 3D planning system, the implant dataset was then registered to the visible implant template in the CT dataset. The distribution of the implant dose was analyzed with respect to defined volumes via dose-volume histograms (DVH). Isodose surfaces, the dose homogeneity index, and dosimetric coverage of the defined volumes were calculated and contrasted. All patients received 32 Gy to the entire implanted volume in 8 fractions of 4 Gy over 4 days. Results: Three-plane implants were used for 7 patients and a two-plane implant for 1 patient. The median number of needles per implant was 16.5 (range

  18. Pilot study in the treatment of endometrial carcinoma with 3D image-based high-dose-rate brachytherapy using modified Heyman packing: Clinical experience and dose-volume histogram analysis

    International Nuclear Information System (INIS)

    Weitmann, Hajo Dirk; Poetter, Richard; Waldhaeusl, Claudia; Nechvile, Elisabeth; Kirisits, Christian; Knocke, Tomas Hendrik

    2005-01-01

    Purpose: The aim of this study was to evaluate dose distribution within uterus (clinical target volume [CTV]) and tumor (gross tumor volume [GTV]) and the resulting clinical outcome based on systematic three-dimensional treatment planning with dose-volume adaptation. Dose-volume assessment and adaptation in organs at risk and its impact on side effects were investigated in parallel. Methods and Materials: Sixteen patients with either locally confined endometrial carcinoma (n = 15) or adenocarcinoma of uterus and ovaries after bilateral salpingo-oophorectomy (n = 1) were included. Heyman packing was performed with mean 11 Norman-Simon applicators (3-18). Three-dimensional treatment planning based on computed tomography (n = 29) or magnetic resonance imaging (n = 18) was done in all patients with contouring of CTV, GTV, and organs at risk. Dose-volume adaptation was achieved by dwell location and time variation (intensity modulation). Twelve patients treated with curative intent received five to seven fractions of high-dose-rate brachytherapy (7 Gy per fraction) corresponding to a total dose of 60 Gy (2 Gy per fraction and α/β of 10 Gy) to the CTV. Four patients had additional external beam radiotherapy (range, 10-40 Gy). One patient had salvage brachytherapy and 3 patients were treated with palliative intent. A dose-volume histogram analysis was performed in all patients. On average, 68% of the CTV and 92% of the GTV were encompassed by the 60 Gy reference volume. Median minimum dose to 90% of CTV and GTV (D90) was 35.3 Gy and 74 Gy, respectively. Results: All patients treated with curative intent had complete remission (12/12). After a median follow-up of 47 months, 5 patients are alive without tumor. Seven patients died without tumor from intercurrent disease after median 22 months. The patient with salvage treatment had a second local recurrence after 27 months and died of endometrial carcinoma after 57 months. In patients treated with palliative intent

  19. Permanent interstitial low-dose-rate brachytherapy for patients with low risk prostate cancer. An interim analysis of 312 cases

    Energy Technology Data Exchange (ETDEWEB)

    Badakhshi, Harun; Graf, Reinhold; Budach, Volker; Wust, Peter [University Hospital Berlin, Department for Radiation Oncology of Charite School of Medicine, Berlin (Germany)

    2015-04-01

    The biochemical relapse-free survival (bRFS) rate after treatment with permanent iodine-125 seed implantation (PSI) or combined seeds and external beam radiotherapy (COMB) for clinical stage T1-T2 localized prostate cancer is a clinically relevant endpoint. The goal of this work was to evaluate the influence of relevant patient- and treatment-related factors. The study population comprised 312 consecutive patients treated with permanent seed implantation. All patients were evaluable for analysis of overall survival (OS) and disease-specific survival (DSS), 230 for bRFS, of which 192 were in the PSI group and 38 in the COMB group. The prescribed minimum peripheral dose was 145 Gy for PSI, for COMB 110 Gy implant and external beam radiotherapy of 45 Gy. The median follow-up time was 33 months (range 8-66 months). bRFS was defined as a serum prostate-specific antigen (PSA) level ≤ 0.2 ng/ml at last follow-up. Overall, the actuarial bRFS at 50 months was 88.4 %. The 50-month bRFS rate for PSI and COMB was 90.9 %, and 77.2 %, respectively. In the univariate analysis, age in the categories ≤ 63 and > 63 years (p < 0.00), PSA nadir (≤ 0.5 ng/ml and > 0.5 ng/ml) and PSA bounce (yes/no) were the significant predicting factors for bRFS. None of the other patient and treatment variables (treatment modality, stage, PSA, Gleason score, risk group, number of risk factors, D90 and various other dose parameters) were found to be a statistically significant predictor of 50-month bRFS. The biochemical failure rates were low in this study. As a proof of principle, our large monocenteric analysis shows that low-dose-rate brachytherapy is an effective and safe procedure for patients with early stage prostate cancer. (orig.) [German] Das biochemisch rezidivfreie Ueberleben (bRFS) nach der Brachytherapie mit permanenter Iod-125-Seed-Implantation (PSI) oder in Kombination mit externer Radiotherapie (COMB) ist beim Patienten mit fruehem Prostatakarzinom (T1/T2) ein relevanter

  20. The mechanical system design of the iridium-192 isotope wire in cervical cancer brachytherapy with medium dose rate

    International Nuclear Information System (INIS)

    Ari Satmoko; Sanda; Tri Harjanto; Atang Susila

    2010-01-01

    In 2010, brachytherapy engineering activities have a purpose to establish a detailed design of the cervical cancer brachytherapy with medium dose rate. The brachytherapy will use an Iridium-92 source with the emiting radiation of 5 to 10 Curies. The source is wrapped in SS-316 capsule and carried by a SS-316 wire having diameter of about 1 mm dan length of 1800 mm. As part of this activity, the preliminary design of the mechanical drive systems for the isotope source has been developed. The technical specifications for the main components of the mechanical drive system have been successfully determined. This is started by studying the concept design, performing calculations, determining technical specifications, and finally defining the main components. From the evaluation, some components were decided: a stepper motor PK264A1-SG10, needle bearing NKI-10/20, spiral tube in SS316-1/8'' with 120 mm in diameter, rubber-based belts with a width of 20 mm, and aluminium drum with a diameter of 100 mm. Not all components could be identified in detail, especially for the components that do not exist in the market place and have to be created ourself. Since the main components have been identified, the detailed design step of the mechanical drive systems for the isotope source can be performed. (author)

  1. A mechanical system design of the iridium-192 isotope wire in cervical cancer brachytherapy with medium dose rate

    International Nuclear Information System (INIS)

    Ari Satmoko; Sanda; Tri Harjanto; Atang Susila

    2010-01-01

    In 2010, brachytherapy engineering development activities have a purpose to establish a detailed design of the cervical cancer brachytherapy with medium dose rate. The brachytherapy will use an Iridium-92 source with the emitting radiation of 5 to 10 Curies. The source is wrapped in SS-316 capsule and carried by a SS-316 wire having diameter of about 1 mm dan length of 1800 mm. As part of this activity, the preliminary design of the mechanical drive systems for the isotope source has been developed. The technical specifications for the main components of the mechanical drive system have been successfully determined. This is started by studying the concept design, performing calculations, determining technical specifications, and finally defining the main components. From the evaluation, some components were decided: a stepper motor PK264A1-SG10, needle bearing NKI-10/20, spiral tube in SS316-1/8'' with 120 mm in diameter, rubber-based belts with a width of 20 mm, and aluminium drum with a diameter of 100 mm. Not all components could be identified in detail, especially for the components that do not exist in the marketplace and have to be created ourself Since the main components have been identified, the detailed design step of the mechanical drive systems for the isotope source can be performed. (author)

  2. Comparison of Dose When Prescribed to Point A and Point H for Brachytherapy in Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gang, Ji Hyeong; Gim, Il Hwan; Hwang, Seon Boong; Kim, Woong; Im, Hyeong Seo; Gang, Jin Mook; Gim, Gi Hwan; Lee, Ah Ram [Dept. of Radiation Oncology, Korea Institute of Radiological and Medical Sciences, Seou (Korea, Republic of)

    2012-09-15

    The purpose of this study is to compare plans prescribed to point A with these prescribed to point H recommended by ABS (American Brachytherapy Society) in high dose rate intracavitary brachytherapy for cervical carcinoma. This study selected 103 patients who received HDR (High Dose Rate) brachytherapy using tandem and ovoids from March 2010 to January 2012. Point A, bladder point, and rectal point conform with Manchester System. Point H conforms with ABS recommendation. Also Sigmoid colon point, and vagina point were established arbitrarily. We examined distance between point A and point H. The percent dose at point A was calculated when 100% dose was prescribed to point H. Additionally, the percent dose at each reference points when dose is prescribed to point H and point A were calculated. The relative dose at point A was lower when point H was located inferior to point A. The relative doses at bladder, rectal, sigmoid colon, and vagina points were higher when point H was located superior to point A, and lower when point H was located inferior to point A. This study found out that as point H got located much superior to point A, the absorbed dose of surrounding normal organs became higher, and as point H got located much inferior to point A, the absorbed dose of surrounding normal organs became lower. This differences dose not seem to affect the treatment. However, we suggest this new point is worth being considered for the treatment of HDR if dose distribution and absorbed dose at normal organs have large differences between prescribed to point A and H.

  3. Radiological protection on interstitial brachytherapy and dose determination and exposure rate of an Ir-192 source through the MCNP-4B

    International Nuclear Information System (INIS)

    Morales L, M.E.

    2006-01-01

    The present work was carried out in the Neurological Sciences Institute having as objective to determine the dose and the rate of exhibition of the sources of Iridium 192, Iodine 125 and Palladium 103; which are used to carry out implant in the Interstitial Brachytherapy according to the TG43. For it we carry out a theoretical calculation, its are defined in the enter file: the geometry, materials of the problem and the radiation source, etc; in the MCNP-4B Monte Carlo code, considering a punctual source and for the dose determination we simulate thermoluminescent dosemeters (TLD): at 5 cm, 50 cm, 100 cm and 200 cm of the source. Our purpose is to analyze the radioprotection measures that should take into account in this Institute in which are carried out brain biopsies using a Micro mar stereotactic mark, and in a near future with the collaboration of a doctor and a cuban physique seeks to be carried out the Interstitial Brachytherapy technique with sources of Ir-192 for patient with tumors like glioblastoma, astrocytoma, etc. (Author)

  4. High-Dose-Rate Monotherapy: Safe and Effective Brachytherapy for Patients With Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Demanes, D. Jeffrey; Martinez, Alvaro A.; Ghilezan, Michel; Hill, Dennis R.; Schour, Lionel; Brandt, David; Gustafson, Gary

    2011-01-01

    Purpose: High-dose-rate (HDR) brachytherapy used as the only treatment (monotherapy) for early prostate cancer is consistent with current concepts in prostate radiobiology, and the dose is reliably delivered in a prospectively defined anatomic distribution that meets all the requirements for safe and effective therapy. We report the disease control and toxicity of HDR monotherapy from California Endocurietherapy (CET) and William Beaumont Hospital (WBH) in low- and intermediate-risk prostate cancer patients. Methods and Materials: There were 298 patients with localized prostate cancer treated with HDR monotherapy between 1996 and 2005. Two biologically equivalent hypofractionation protocols were used. At CET the dose was 42 Gy in six fractions (two implantations 1 week apart) delivered to a computed tomography–defined planning treatment volume. At WBH the dose was 38 Gy in four fractions (one implantation) based on intraoperative transrectal ultrasound real-time treatment planning. The bladder, urethral, and rectal dose constraints were similar. Toxicity was scored with the National Cancer Institute Common Toxicity Criteria for Adverse Events version 3. Results: The median follow-up time was 5.2 years. The median age of the patients was 63 years, and the median value of the pretreatment prostate-specific antigen was 6.0 ng/mL. The 8-year results were 99% local control, 97% biochemical control (nadir +2), 99% distant metastasis–free survival, 99% cause-specific survival, and 95% overall survival. Toxicity was scored per event, meaning that an individual patient with more than one symptom was represented repeatedly in the morbidity data table. Genitourinary toxicity consisted of 10% transient Grade 2 urinary frequency or urgency and 3% Grade 3 episode of urinary retention. Gastrointestinal toxicity was <1%. Conclusions: High disease control rates and low morbidity demonstrate that HDR monotherapy is safe and effective for patients with localized prostate cancer.

  5. Favorable Preliminary Outcomes for Men With Low- and Intermediate-risk Prostate Cancer Treated With 19-Gy Single-fraction High-dose-rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Krauss, Daniel J., E-mail: dkrauss@beaumont.edu [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Ye, Hong [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Martinez, Alvaro A. [21st Century Oncology, Farmington Hills, Michigan (United States); Mitchell, Beth; Sebastian, Evelyn; Limbacher, Amy; Gustafson, Gary S. [Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States)

    2017-01-01

    Purpose: To report the toxicity and preliminary clinical outcomes of a prospective trial evaluating 19-Gy, single-fraction high-dose-rate (HDR) brachytherapy for men with low- and intermediate-risk prostate cancer. Methods and Materials: A total of 63 patients were treated according to an institutional review board-approved prospective study of single-fraction HDR brachytherapy. Eligible patients had tumor stage ≤T2a, prostate-specific antigen level ≤15 ng/mL, and Gleason score ≤7. Patients with a prostate gland volume >50 cm{sup 3} and baseline American Urologic Association symptom score >12 were ineligible. Patients underwent transrectal ultrasound-guided transperineal implantation of the prostate, followed by single-fraction HDR brachytherapy. Treatment was delivered using {sup 192}Ir to a dose of 19 Gy prescribed to the prostate, with no additional margin applied. Results: Of the 63 patients, 58 had data available for analysis. Five patients had withdrawn consent during the follow-up period. The median follow-up period was 2.9 years (range 0.3-5.2). The median age was 61.4 years. The median gland volume at treatment was 34.8 cm{sup 3}. Of the 58 patients, 91% had T1 disease, 71% had Gleason score ≤6 (29% with Gleason score 7), and the median pretreatment prostate-specific antigen level was 5.1 ng/mL. The acute and chronic grade 2 genitourinary toxicity incidence was 12.1% and 10.3%, respectively. No grade 3 urinary toxicity occurred. No patients experienced acute rectal toxicity grade ≥2, and 2 experienced grade ≥2 chronic gastrointestinal toxicity. Three patients experienced biochemical failure, yielding a 3-year cumulative incidence estimate of 6.8%. Conclusions: Single-fraction HDR brachytherapy is well-tolerated, with favorable preliminary biochemical and clinical disease control rates.

  6. High dose rate interstitial brachytherapy with external beam irradiation for localized prostate cancer. Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Hiratsuka, Junichi; Jo, Yoshimasa; Yoden, Eisaku; Tanaka, Hiroyoshi; Imajo, Yoshinari [Kawasaki Medical School, Kurashiki, Okayama (Japan); Nagase, Naomi; Narihiro, Naomasa; Kubota, Juichi

    2000-12-01

    This study was undertaken to assess the biochemical and pathological results of combined external beam radiotherapy and high dose rate Ir-192 brachytherapy (HDR-Ir192) for clinically localized prostate cancer. Between October 1997 and August 1999, 39 evaluable patients with adenocarcinoma of prostate diagnosed by biopsy were treated with interstitial and external beam irradiation. Patients ranged in age from 58-82 years, with a mean of 69.7 years. T1c, T2 and T3 tumors, according to the UICC classification system (1997), were found in 7, 21 and 11 cases respectively. The mean initial pre-treatment PSA was 35.9 ng/ml (median 13.2), with 77% of the patients having had a pre-treatment PSA greater than 10 ng/ml. Of all patients, 17 had received pre-treatment hormonal therapy. Hormonal pretreatment was stopped at the beginning of radiotherapy in all cases. External beam four-field box irradiation was given to the small pelvis to a dose of 45 Gy/25 fractions. Three HDR-Ir192 treatments were given over a 30-h period, with 5.5 Gy per fraction at the circumference of the prostate gland over the course of this study. Biochemical failure was defined as a PSA level >1.5 ng/ml and rising on three consecutive values. If serial post-treatment PSA levels showed a continuous downward trend, failure was not scored. The patient with clinical evidence of progression was classified as a clinical failure. The median follow-up at the time of evaluation was 19.6 months. A post-treatment PSA level {<=}1.0 ng/ml was seen in 26 (67%) patients, and values from >1.0 to {<=}2.0 ng/ml were seen in 10 (26%) patients. Biochemical failure was not seen in 38 patients except for one patient who developed a distant bone metastasis with negative prostatic biopsy 15 months after treatment. Biochemical control rate was 100% (38/38) except for the patient with bone metastasis classified as clinical failure. Negative biopsies 18 months after treatment were found in 93% (14/15) of patients. Only one patient

  7. Development of brachytherapy medium doserate

    International Nuclear Information System (INIS)

    Atang Susila; Ari Satmoko; Ahmad Rifai; Kristiyanti

    2010-01-01

    Brachytherapy has proven to be an effective treatment for different types of cancers and it become a common treatment modality in most radiotherapy clinics. PRPN has had experience in development of Low Dose Rate Brachytherapy for cervix cancer treatment. However the treatment process using LDR device needs 5 hours in time that the patient feel uncomfort. Therefore PRPN develops Medium Dose Rate Brachytherapy with radiation activity not more than 5 Currie. The project is divided into two stages. Purchasing of TPS software and TDS design are held in 2010, and the construction will be in 2011. (author)

  8. Artificial neural network based gynaecological image-guided adaptive brachytherapy treatment planning correction of intra-fractional organs at risk dose variation.

    Science.gov (United States)

    Jaberi, Ramin; Siavashpour, Zahra; Aghamiri, Mahmoud Reza; Kirisits, Christian; Ghaderi, Reza

    2017-12-01

    Intra-fractional organs at risk (OARs) deformations can lead to dose variation during image-guided adaptive brachytherapy (IGABT). The aim of this study was to modify the final accepted brachytherapy treatment plan to dosimetrically compensate for these intra-fractional organs-applicators position variations and, at the same time, fulfilling the dosimetric criteria. Thirty patients with locally advanced cervical cancer, after external beam radiotherapy (EBRT) of 45-50 Gy over five to six weeks with concomitant weekly chemotherapy, and qualified for intracavitary high-dose-rate (HDR) brachytherapy with tandem-ovoid applicators were selected for this study. Second computed tomography scan was done for each patient after finishing brachytherapy treatment with applicators in situ. Artificial neural networks (ANNs) based models were used to predict intra-fractional OARs dose-volume histogram parameters variations and propose a new final plan. A model was developed to estimate the intra-fractional organs dose variations during gynaecological intracavitary brachytherapy. Also, ANNs were used to modify the final brachytherapy treatment plan to compensate dosimetrically for changes in 'organs-applicators', while maintaining target dose at the original level. There are semi-automatic and fast responding models that can be used in the routine clinical workflow to reduce individually IGABT uncertainties. These models can be more validated by more patients' plans to be able to serve as a clinical tool.

  9. Artificial neural network based gynaecological image-guided adaptive brachytherapy treatment planning correction of intra-fractional organs at risk dose variation

    Directory of Open Access Journals (Sweden)

    Ramin Jaberi

    2017-12-01

    Full Text Available Purpose : Intra-fractional organs at risk (OARs deformations can lead to dose variation during image-guided adaptive brachytherapy (IGABT. The aim of this study was to modify the final accepted brachytherapy treatment plan to dosimetrically compensate for these intra-fractional organs-applicators position variations and, at the same time, fulfilling the dosimetric criteria. Material and methods : Thirty patients with locally advanced cervical cancer, after external beam radiotherapy (EBRT of 45-50 Gy over five to six weeks with concomitant weekly chemotherapy, and qualified for intracavitary high-dose-rate (HDR brachytherapy with tandem-ovoid applicators were selected for this study. Second computed tomography scan was done for each patient after finishing brachytherapy treatment with applicators in situ. Artificial neural networks (ANNs based models were used to predict intra-fractional OARs dose-volume histogram parameters variations and propose a new final plan. Results : A model was developed to estimate the intra-fractional organs dose variations during gynaecological intracavitary brachytherapy. Also, ANNs were used to modify the final brachytherapy treatment plan to compensate dosimetrically for changes in ‘organs-applicators’, while maintaining target dose at the original level. Conclusions : There are semi-automatic and fast responding models that can be used in the routine clinical workflow to reduce individually IGABT uncertainties. These models can be more validated by more patients’ plans to be able to serve as a clinical tool.

  10. Neither high-dose nor low-dose brachytherapy increases flap morbidity in salvage treatment of recurrent head and neck cancer

    Directory of Open Access Journals (Sweden)

    Peter W. Henderson

    2016-08-01

    Full Text Available Purpose: While brachytherapy is often used concurrently with flap reconstruction following surgical ablation for head and neck cancer, it remains unclear whether it increases morbidity in the particularly high risk subset of patients undergoing salvage treatment for recurrent head and neck cancer (RH&NC. Material and methods : A retrospective chart review was undertaken that evaluated patients with RH&NC who underwent flap coverage after surgical re-resection and concomitant brachytherapy. The primary endpoint was flap viability, and the secondary endpoints were flap and recipient site complications. Results : In the 23 subjects included in series, flap viability and skin graft take was 100%. Overall recipient site complication rate was 34.8%, high-dose radiation (HDR group 50%, and low-dose radiation (LDR group 29.4%. There was no statistically significant difference between these groups. Conclusions : In patients who undergo flap reconstruction and immediate postoperative radiotherapy following salvage procedures for RH&NC, flap coverage of defects in combination with brachytherapy remains a safe and effective means of providing stable soft tissue coverage.

  11. In vivo assessment of the gastric mucosal tolerance dose after single fraction, small volume irradiation of liver malignancies by computed tomography-guided, high-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Streitparth, Florian; Pech, Maciej; Boehmig, Michael; Ruehl, Ricarda; Peters, Nils; Wieners, Gero; Steinberg, Johannes; Lopez-Haenninen, Enrique; Felix, Roland; Wust, Peter; Ricke, Jens

    2006-01-01

    Purpose: The aim of this study was to assess the tolerance dose of gastric mucosa for single-fraction computed tomography (CT)-guided, high-dose-rate (HDR) brachytherapy of liver malignancies. Methods and Materials: A total of 33 patients treated by CT-guided HDR brachytherapy of liver malignancies in segments II and/or III were included. Dose planning was performed upon a three-dimensional CT data set acquired after percutaneous applicator positioning. All patients received gastric protection post-treatment. For further analysis, the contours of the gastric wall were defined in every CT slice using Brachyvision Software. Dose-volume histograms were calculated for each treatment and correlated with clinical data derived from questionnaires assessing Common Toxicity Criteria (CTC). All patients presenting symptoms of upper GI toxicity were examined endoscopically. Results: Summarizing all patients the minimum dose applied to 1 ml of the gastric wall (D 1ml ) ranged from 6.3 to 34.2 Gy; median, 14.3 Gy. Toxicity was present in 18 patients (55%). We found nausea in 16 (69%), emesis in 9 (27%), cramping in 13 (39%), weight loss in 12 (36%), gastritis in 4 (12%), and ulceration in 5 patients (15%). We found a threshold dose D 1ml of 11 Gy for general gastric toxicity and 15.5 Gy for gastric ulceration verified by an univariate analysis (p = 0.01). Conclusions: For a single fraction, small volume irradiation we found in the upper abdomen a threshold dose D 1ml of 15.5 Gy for the clinical endpoint ulceration of the gastric mucosa. This in vivo assessment is in accordance with previously published tolerance data

  12. Effects of prescription depth, cylinder size, treatment length, tip space, and curved end on doses in high-dose-rate vaginal brachytherapy

    International Nuclear Information System (INIS)

    Li Shidong; Aref, Ibrahim; Walker, Eleanor; Movsas, Benjamin

    2007-01-01

    Purpose: To determine the effects of the prescription depth, cylinder size, treatment length, tip space, and curved end on high-dose-rate vaginal brachytherapy (HDR-VBT) of endometrial cancer. Methods and Materials: Treatment plans were prescribed and optimized based on points at the cylinder surface or at 0.5-cm depth. Cylinder sizes ranging from 2 to 4 cm in diameter, and treatment lengths ranging from 3 to 8 cm were used. Dose points in various depths were precisely defined along the cylinder dome. The given dose and dose uniformity to a depth of interest were measured by the mean dose (MD) and standard deviation (SD), respectively, among the dose points belonging to the depth. Dose fall-off beyond the 0.5 cm treatment depth was determined by the ratio of MD at 0.75-cm depth to MD at 0.5-cm depth. Results: Dose distribution varies significantly with different prescriptions. The surface prescription provides more uniform doses at all depths in the target volume, whereas the 0.5-cm depth prescription creates larger dose variations at the cylinder surface. Dosimetric uncertainty increases significantly (>30%) with shorter tip space. Extreme hot (>150%) and cold spots (<60%) occur if no optimization points were placed at the curved end. Conclusions: Instead of prescribing to a depth of 0.5 cm, increasing the dose per fraction and prescribing to the surface with the exact surface points around the cylinder dome appears to be the optimal approach

  13. Evaluation of radiation doses on critical organs in the treatment of cancer of the cervix using HDR-brachytherapy

    International Nuclear Information System (INIS)

    Soares, Taciana; Jansem, Teresa

    2000-01-01

    High dose-rate (HDR) brachytherapy is one type of treatment of the cervix carcinoma. During the planning for this therapy, especial attention is given to proximal normal organs such as bladder and rectum. In fact, due to their radiosensibility and localization, bladder and rectum are considered as critical organs. In this work we have studied the influence of the positioning of patient legs in the dose delivered to these critical organs in the treatment of cancer of the cervix using HDR-brachytherapy. (author)

  14. Optimal bladder filling during high-dose-rate intracavitary brachytherapy for cervical cancer: a dosimetric study

    Directory of Open Access Journals (Sweden)

    Umesh Mahantshetty

    2017-04-01

    Full Text Available Purpose: The aim of this study is to compare 3D dose volume histogram (DVH parameters of bladder and other organs at risk with different bladder filling protocol during high-dose-rate intracavitary brachytherapy (HDR-ICBT in cervical cancer, and to find optimized bladder volume. Material and methods : This dosimetric study was completed with 21 patients who underwent HDR-ICBT with computed tomography/magnetic resonance compatible applicator as a routine treatment. Computed tomography planning was done for each patient with bladder emptied (series 1, after 50 ml (series 2, and 100 ml (series 3 bladder filling with a saline infusion through the bladder catheter. Contouring was done on the Eclipse Planning System. 7 Gy to point A was prescribed with the standard loading patterns. Various 3D DVH parameters including 0.1 cc, 1 cc, 2 cc doses and mean doses to the OAR’s were noted. Paired t-test was performed. Results : The mean (± SD bladder volume was 64.5 (± 25 cc, 116.2 (± 28 cc, and 172.9 (± 29 cc, for series 1, 2, and 3, respectively. The 0.1 cm 3 ,1 cm 3 , 2 cm 3 mean bladder doses for series 1, series 2, and series 3 were 9.28 ± 2.27 Gy, 7.38 ± 1.72 Gy, 6.58 ± 1.58 Gy; 9.39 ± 2.28 Gy, 7.85 ± 1.85 Gy, 7.05 ± 1.59 Gy, and 10.09 ± 2.46 Gy, 8.33 ± 1.75 Gy, 7.6 ± 1.55 Gy, respectively. However, there was a trend towards higher bladder doses in series 3. Similarly, for small bowel dose 0.1 cm 3 , 1 cm 3 , and 2 cm 3 in series 1, 2, and 3 were 5.44 ± 2.2 Gy, 4.41 ± 1.84 Gy, 4 ± 1.69 Gy; 4.57 ± 2.89 Gy, 3.78 ± 2.21 Gy, 3.35 ± 2.02 Gy, and 4.09 ± 2.38 Gy, 3.26 ± 1.8 Gy, 3.05 ± 1.58 Gy. Significant increase in small bowel dose in empty bladder (series 1 compared to full bladder (series 3 (p = 0.03 was noted. However, the rectal and sigmoid doses were not significantly affected with either series. Conclusions : Bladder filling protocol with 50 ml and 100 ml was well tolerated and achieved a reasonably reproducible bladder volume

  15. Pilot Quality Control Program for Brachytherapy of Low Dose Rate at the General Hospital of Mexico

    Science.gov (United States)

    Álvarez R., J. T.; Tovar M., V.; Salinas, B.; Hernández O., O.; Santillán B., L.; Molero M., C.; Montoya M., J.

    2004-09-01

    We describe the pilot quality control program for brachytherapy of low dose rate proposed to be used in the Radiotherapy Department at the General Hospital of Mexico. The program consists of three parts: a) development of calibration procedures, performed in terms of air-kerma strength for calibration of 137Cs and 192Ir brachytherapy sources, and for the calibration of well-type ionization chambers for 137Cs, b) performance of localisation and reconstruction techniques for radioactive sources with a Baltas' phantom. The results obtained for the media deviation , are in the optimum level, ± 0.5 mm hospital. It consists on the characterisation of a TLD-100 powder dosimetry system at SSDL: The calibration curves for powder response (nC or nC/ mg) vs Dw and the control charts for the Harshaw 3500 reader were obtained. The statistical validation of the calibration curve by normality of the residuals and the lack of fit tests were realised. In the other hand, TLD's were irradiated in the hospital to a nominal Dw = 2 Gy with sources of 137Cs. The percent deviations Δ%, between the Dw imparted by the Hospital and the determined by SSDL, are 1.2% Δ⩽ 6.5 % which are consistent with the expanded uncertainty U% for DW, 5.6 U% 10%.

  16. How to optimize therapeutic ratio in brachytherapy of head and neck squamous cell carcinoma?

    International Nuclear Information System (INIS)

    Mazeron, J.J.; Simon, J.M.; Hardiman, C.; Gerbaulet, A.

    1998-01-01

    Considerable experience has been accumulated with low dose rate (LDR) brachytherapy in the treatment of squamous cell carcinoma of the oral cavity and oropharynx, 4 cm or less in diameter. Recent analysis of large clinical series provided data indicating that modalities of LDR brachytherapy should be optimized in treating these tumours for increasing therapeutic ratio. LDR brachytherapy is now challenged by high dose rate (HDR) brachytherapy and pulsed dose rate (PDR) brachytherapy. Preliminary results obtained with the last two modalities are discussed in comparison with those achieved with LDR brachytherapy. (orig.)

  17. Intravascular ultrasound based dose assessment in endovascular brachytherapy

    International Nuclear Information System (INIS)

    Catalano, Gianpiero; Tamburini, Vittorio; Colombo, Antonio; Nishida, Takahiro; Parisi, Giovanni; Mazzetta, Chiara; Orecchia, Roberto

    2003-01-01

    Background: the role of endovascular brachytherapy in restenosis prevention is well documented. Dose is usually prescribed at a fixed distance from the source axis by angiographic quantification of vessel diameter. Recently, intravascular ultrasound (IVUS) was introduced in dose prescription, allowing a better evaluation of the vessel anatomy. This study retrospectively explores the difference between prescription following angiographic vessel sizing and delivered dose calculated with IVUS. Methods and results: Seventeen lesions were studied with IVUS, identifying on irradiated segment, three sections on which measuring minimal and maximal distance from the centre of IVUS catheter to the adventitia; using dedicated software, corresponding doses were calculated. The dose ranged widely, with maximal and minimal values of 71.6 and 4.9 Gy; furthermore, heterogeneity in dose among different sections was observed. In the central section, the maximal dose was 206% of the one prescribed with the QCA model at 2 mm from the source axis, while the minimal dose was 96%. In proximal and distal sections, respective values were 182, 45, 243, and 122%. Conclusions: Our analysis confirmed the dose inhomogeneity delivered with an angiographic fixed-dose prescription strategy. A dose variation was found along the irradiated segment due to the differences in vessel thickness. IVUS emerged as an important tool in endovascular brachytherapy, especially for irregular-shaped vessels

  18. Phase I/II trial of single-fraction high-dose-rate brachytherapy-boosted hypofractionated intensity-modulated radiation therapy for localized adenocarcinoma of the prostate.

    Science.gov (United States)

    Myers, Michael A; Hagan, Michael P; Todor, Dorin; Gilbert, Lynn; Mukhopadhyay, Nitai; Randolf, Jessica; Heimiller, Jeffrey; Anscher, Mitchell S

    2012-01-01

    A Phase I/II protocol was conducted to examine the toxicity and efficacy of the combination of intensity-modulated radiation therapy (IMRT) with a single-fraction high-dose-rate (HDR) brachytherapy implant. From 2001 through 2006, 26 consecutive patients were treated on the trial. The primary objective was to demonstrate a high rate of completion without experiencing a treatment-limiting toxicity. Eligibility was limited to patients with T stage ≤2b, prostate-specific antigen (PSA) ≤20, and Gleason score ≤7. Treatment began with a single HDR fraction of 6Gy to the entire prostate and 9Gy to the peripheral zone, followed by IMRT optimized to deliver in 28 fractions with a normalized total dose of 70Gy. Patients received 50.4Gy to the pelvic lymph node. The prostate dose (IMRT and HDR) resulted in an average biologic equivalent dose >128Gy (α/β=3). Patients whose pretreatment PSA was ≥10ng/mL, Gleason score 7, or stage ≥T2b received short-term androgen ablation. Median followup was 53 months (9-68 months). There were no biochemical failures by either the American Society of Therapeutic Radiology and Oncology or the Phoenix definitions. The median nadir PSA was 0.32ng/mL. All the 26 patients completed the treatment as prescribed. The rate of Grade 3 late genitourinary toxicity was 3.8% consisting of a urethral stricture. There was no other Grade 3 or 4 genitourinary or gastrointestinal toxicities. Single-fraction HDR-boosted IMRT is a safe effective method of dose escalation for localized prostate cancer. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  19. Interstitial prostate brachytherapy. LDR-PDR-HDR

    International Nuclear Information System (INIS)

    Kovacs, Gyoergy; Hoskin, Peter

    2013-01-01

    The first comprehensive overview of interstitial brachytherapy for the management of local or locally advanced prostate cancer. Written by an interdisciplinary team who have been responsible for the successful GEC-ESTRO/EAU Teaching Course. Discusses in detail patient selection, the results of different methods, the role of imaging, and medical physics issues. Prostate brachytherapy has been the subject of heated debate among surgeons and the proponents of the various brachytherapy methods. This very first interdisciplinary book on the subject provides a comprehensive overview of innovations in low dose rate (LDR), high dose rate (HDR), and pulsed dose rate (PDR) interstitial brachytherapy for the management of local or locally advanced prostate cancer. In addition to detailed chapters on patient selection and the use of imaging in diagnostics, treatment guidance, and implantation control, background chapters are included on related medical physics issues such as treatment planning and quality assurance. The results obtained with the different treatment options and the difficult task of salvage treatment are fully discussed. All chapters have been written by internationally recognized experts in their fields who for more than a decade have formed the teaching staff responsible for the successful GEC-ESTRO/EAU Prostate Brachytherapy Teaching Course. This book will be invaluable in informing residents and others of the scientific background and potential of modern prostate brachytherapy. It will also prove a useful source of up-to-date information for those who specialize in prostate brachytherapy or intend to start an interstitial brachytherapy service.

  20. Postal auditing methodology used to find out the performance of high rate brachytherapy equipment

    International Nuclear Information System (INIS)

    Morales, J.A.; Campa, R.

    1998-01-01

    This work describes results from a methodology implemented at the Secondary Laboratory for Dosimetric Calibration at CPHR used to check the brachytherapy performance at high doses rate using Cesium 137 or cobalt 60 sources

  1. The American brachytherapy society survey of brachytherapy practice for carcinoma of the cervix in the United States.

    Science.gov (United States)

    Nag, S; Orton, C; Young, D; Erickson, B

    1999-04-01

    The purpose of this study was to survey the brachytherapy practice for cervical cancer in the United States. The Clinical Research Committee of the American Brachytherapy Society (ABS) performed a retrospective survey of individual physicians of the ABS and American Society of Therapeutic Radiologists and Oncologists regarding the details of the brachytherapy techniques they personally used in the treatment of cervical cancer patients for the year 1995. The replies (some of which may have been an estimate only) were tabulated. The scope of this survey did not allow us to verify the data by chart audits. A total of about 3500 questionnaires were mailed out; 521 responses were received. Of these responders, 206 (40%) did not perform any brachytherapy for carcinoma of the cervix in 1995. Of the other 315 responders reporting a total of 4892 patients treated in 1995, 88% used low dose rate (LDR) while 24% used high dose rate (HDR). There was a wide variation in the doses used. For LDR treatments, the median total external beam radiation therapy (EBRT) dose was 45 and 50 Gy and the LDR dose was 42 and 45 Gy for early and advanced cancers, respectively. For HDR treatments, the median EBRT dose was 48 and 50 Gy and the median HDR dose was 29 and 30 Gy for early and advanced cancers, respectively. The median dose per fraction was 6 Gy for a median of five fractions. Interstitial brachytherapy was used as a component of the treatment in 6% of the patients by 21% of responders. Very few responders treated with pulsed or medium dose rates. This retrospective survey showed the current brachytherapy practice pattern in the treatment of cervical cancer in the United States and can serve as a basis for future prospective national brachytherapy data registry. There was wide variation in the practice pattern, emphasizing the urgent need for consensus on these issues. Copyright 1999 Academic Press.

  2. High-dose-rate intracavitary brachytherapy combined with external beam radiotherapy for stage IIIb adenocarcinoma of the uterine cervix in Japan. A multi-institutional study of Japanese Society of Therapeutic Radiology and Oncology 2006-2007 (Study of JASTRO 2006-2007)

    International Nuclear Information System (INIS)

    Niibe, Yuzuru; Kenjo, Masahiro; Onishi, Hiroshi

    2010-01-01

    The current study was a retrospective questionnaire survey of stage IIIb adenocarcinoma of the uterine cervix treated with high-dose-rate intracavitary brachytherapy combined with external beam radiation therapy in Japan aimed to investigate the optimal dose on the basis of the biological effective dose and prognostic factors. Between 1990 and 2000, 61 patients with stage IIIb adenocarcinoma of the uterine cervix underwent high-dose-rate intracavitary brachytherapy combined with external beam radiation therapy in 19 major hospitals in Japan. This retrospective questionnaire survey was performed by mail including survey charts to be fulfilled by radiation oncologists in these 19 major hospital. Fifty had only adenocarcinoma components and 11 had adenosquamous cell carcinoma components. All patients were treated with high-dose-rate intracavitary brachytherapy combined with external beam radiation therapy. Total biological effective dose (T-BED 10 ) was calculated from the sum of the biological effective doses of the external beam radiation therapy and the intracavitary brachytherapy. Thirty-two patients underwent chemotherapy. The 5-year overall survival rate of all patients was 20.2%. Stratified by total biological effective dose, the 5-year overall survival rate was 0% for T-BED 10 10 between 75 and 100 Gy and 0% for T-BED 10 >110 Gy (P=0.15). Stratified by histopathology, the 5-year overall survival rate was 22.1% for adenocarcinoma and 13.6% for adenosquamous cell carcinoma (P=0.43). Stratified by chemotherapy, the 5-year overall survival rate was 20.3% in patients who received chemotherapy and 20.4% in patients who did not receive chemotherapy (P=0.96). The 5-year overall survival rate of stage IIIb adenocarcinoma of the uterine cervix in this retrospective questionnaire survey was 20.2%. The optimal T-BED 10 and evident prognostic factors were not clear from this questionnaire survey. (author)

  3. The impact of body mass index on dosimetric quality in low-dose-rate prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Michelle I. Echevarria

    2016-11-01

    Full Text Available Purpose : Low-dose-rate (LDR brachytherapy has been established as an effective and safe treatment option for men with low and intermediate risk prostate cancer. In this retrospective analysis, we sought to study the effect of body mass index (BMI on post-implant dosimetric quality. Material and methods : After institutional approval, records of patients with non-metastatic prostate cancer treated in Puerto Rico with LDR brachytherapy during 2008-2013 were reviewed. All patients were implanted with 125I seeds to a prescription dose of 145 Gy. Computed tomography (CT based dosimetry was performed 1 month after implant. Patients with at least 1 year of prostate-specific antigen (PSA follow-up were included. Factors predictive of adequate D90 coverage (≥ 140 Gy were compared via the Pearson χ2 or Wilcoxon rank-sum test as appropriate. Results : One-hundred and four patients were included in this study, with 53 (51% patients having a D90 ≥ 140 Gy. The only factor associated with a dosimetric coverage detriment (D90 < 140 Gy was BMI ≥ 25 kg/m2 (p = 0.03. Prostate volume (p = 0.26, initial PSA (p = 0.236, age (p = 0.49, hormone use (p = 0.93, percent of cores positive (p = 0.95, risk group (p = 0.24, tumor stage (p = 0.66, and Gleason score (p = 0.61 did not predict D90. Conclusions : In this study we show that BMI is a significant pre-implant predictor of D90 (< 140 Gy vs. ≥ 140 Gy. Although other studies have reported that prostate volume also affects D90, our study did not find this correlation to be statistically significant, likely because all of our patients had a prostate volume 140 Gy.

  4. High-dose rate iridium-192 brachytherapy with flexible applicator. A trial toward decrease of stress during treatment and improvement of quality of life

    International Nuclear Information System (INIS)

    Inoue, Keiji; Kasahara, Kotaro; Karashima, Takashi; Inoue, Yuichiro; Kariya, Shinji; Inomata, Taisuke; Yoshida, Shoji; Shuin, Taro

    2001-01-01

    We tried to improve the materials and methods of high-dose rate Iridium-192 brachytherapy for localized prostate cancer and evaluated the stress during the treatment in 20 patients with whom the therapy was performed. Rigid applicators made of stainless steel of 1.6 mm in diameter were indwelt with a template as usual for 30 hours in 14 patients (group A). Flexible applicators made of polyoxymethylene rosin (POM) of 2.0 mm in diameter were indwelt without a template for 30 hours after the applicator insertion in 6 patients (group B). We made inquiries about lumbago, inconvenience and necessity of assistant help and sleep in the course of therapy, and urinary incontinence and erectile function after the course of therapy as the QOL. The stress during the course of therapy in the patients of group B was obviously less than that of group A. There were no significant differences in urinary incontinence and erectile function after the course of therapy between group A and B. In this study, our trial successfully reduced the stress during the course of therapy in the patients with localized prostate cancer in the course of high-dose rate Iridium-192 brachytherapy. (author)

  5. High-dose rate iridium-192 brachytherapy with flexible applicator. A trial toward decrease of stress during treatment and improvement of quality of life

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Keiji; Kasahara, Kotaro; Karashima, Takashi; Inoue, Yuichiro; Kariya, Shinji; Inomata, Taisuke; Yoshida, Shoji; Shuin, Taro [Kochi Medical School, Nankoku (Japan)

    2001-07-01

    We tried to improve the materials and methods of high-dose rate Iridium-192 brachytherapy for localized prostate cancer and evaluated the stress during the treatment in 20 patients with whom the therapy was performed. Rigid applicators made of stainless steel of 1.6 mm in diameter were indwelt with a template as usual for 30 hours in 14 patients (group A). Flexible applicators made of polyoxymethylene rosin (POM) of 2.0 mm in diameter were indwelt without a template for 30 hours after the applicator insertion in 6 patients (group B). We made inquiries about lumbago, inconvenience and necessity of assistant help and sleep in the course of therapy, and urinary incontinence and erectile function after the course of therapy as the QOL. The stress during the course of therapy in the patients of group B was obviously less than that of group A. There were no significant differences in urinary incontinence and erectile function after the course of therapy between group A and B. In this study, our trial successfully reduced the stress during the course of therapy in the patients with localized prostate cancer in the course of high-dose rate Iridium-192 brachytherapy. (author)

  6. Six fractions per week of external beam radiotherapy and high-dose-rate brachytherapy for carcinoma of the uterine cervix: A phase I/II study

    International Nuclear Information System (INIS)

    Yoon, Sang Min; Huh, Seung Jae; Park, Won; Lee, Jeung Eun; Park, Young Je; Nam, Hee Rim; Lim, Do Hoon; Ahn, Yong Chan

    2006-01-01

    Purpose: This study evaluated the treatment results of external beam radiotherapy administered in six fractions per week and high-dose-rate (HDR) brachytherapy for the treatment of cervical cancer. Methods and Materials: From July 2000 to July 2003, 43 patients were enrolled in this study. The patients received 45 Gy from a 10-MV photon beam using four-field box or anterior-posterior beams. Parametrial regions and the pelvic side walls were boosted with up to 50.4 Gy using a midline block. The daily fraction dose was 1.8 Gy administered in six-weekly fractions, from Monday to Saturday. HDR brachytherapy was also delivered at doses of 24 Gy to point A in six fractions twice a week. The median follow-up time was 37 months (range, 9-60 months). Results: The median overall treatment time was 51 days for all patients (range, 44-62 days). Thirty-four patients (79.1%) achieved complete remission and 8 (18.6%) achieved partial remission after radiotherapy. Locoregional recurrence occurred in 5 patients (11.6%), and a distant metastasis was encountered in 6 patients (13.9%). The 3-year overall survival, locoregional, and distant metastasis-free survival rates were 74.7%, 87.8%, and 84.7%, respectively. Grade 2 and 3 late rectal complications were encountered in 3 (6.5%) and 1 (2.2%), respectively. There were no Grade 3 late bladder complications. Conclusions: Six fractions per week of external beam radiotherapy and HDR brachytherapy is an effective treatment for patients with a carcinoma of the uterine cervix and can be used as a possible alternative to concomitant chemoradiotherapy in elderly patients or in patients with co-morbidity

  7. High-Dose-Rate Endobronchial Brachytherapy for Recurrent Airway Obstruction From Hyperplastic Granulation Tissue

    International Nuclear Information System (INIS)

    Tendulkar, Rahul D.; Fleming, Peter A.; Reddy, Chandana A.; Gildea, Thomas R.; Machuzak, Michael; Mehta, Atul C.

    2008-01-01

    Purpose: Benign endobronchial granulation tissue causes airway obstruction in up to 20% of patients after lung transplantation or stent placement. High-dose-rate endobronchial brachytherapy (HDR-EB) has been successful in some cases refractory to standard bronchoscopic interventions. Methods and Materials: Between September 2004 and May 2005, 8 patients with refractory benign airway obstruction were treated with HDR-EB, using one to two fractions of Ir-192 prescribed to 7.1 Gy at a radius of 1 cm. Charts were retrospectively reviewed to evaluate subjective clinical response, forced expiratory volume in 1 second (FEV 1 ), and frequency of therapeutic bronchoscopies over 6-month periods before and after HDR-EB. Results: The median follow-up was 14.6 months, and median survival was 10.5 months. The mean number of bronchoscopic interventions improved from 3.1 procedures in the 6-month pretreatment period to 1.8 after HDR-EB. Mean FEV 1 improved from 36% predicted to 46% predicted. Six patients had a good-to-excellent subjective early response, but only one maintained this response beyond 6 months, and this was the only patient treated with HDR-EB within 24 h from the most recent bronchoscopic intervention. Five patients have expired from causes related to their chronic pulmonary disease, including one from hemoptysis resulting from a bronchoarterial fistula. Conclusion: High-dose-rate-EB may be an effective treatment for select patients with refractory hyperplastic granulation tissue causing recurrent airway stenosis. Performing HDR-EB within 24-48 h after excision of obstructive granulation tissue could further improve outcomes. Careful patient selection is important to maximize therapeutic benefit and minimize toxicity. The optimal patient population, dose, and timing of HDR-EB should be investigated prospectively

  8. The usefulness of metal markers for CTV-based dose prescription in high-dose-rate interstitial brachytherapy

    International Nuclear Information System (INIS)

    Yoshida, Ken; Mitomo, Masanori; Nose, Takayuki; Koizumi, Masahiko; Nishiyama, Kinji; Yoshida, Mineo

    2002-01-01

    We employ a clinical target volume (CTV)-based dose prescription for high-dose-rate (HDR) interstitial brachytherapy. However, it is not easy to define CTV and organs at risk (OAR) from X-ray film or CT scanning. To solve this problem, we have utilized metal markers since October 1999. Moreover, metal markers can help modify dose prescription. By regulating the doses to the metal markers, refining the dose prescription can easily be achieved. In this research, we investigated the usefulness of the metal markers. Between October 1999 and May 2001, 51 patients were implanted with metal markers at Osaka Medical Center for Cancer and Cardiovascular Diseases (OMCC), Osaka National Hospital (ONH) and Sanda City Hospital (SCH). Forty-nine patients (head and neck: 32; pelvis: 11; soft tissue: 3; breast: 3) using metal markers were analyzed. During operation, we implanted 179 metal markers (49 patients) to CTV and 151 markers (26 patients) to OAR. At treatment planning, CTV was reconstructed judging from the metal markers, applicator position and operation records. Generally, we prescribed the tumoricidal dose to an isodose surface that covers CTV. We also planned to limit the doses to OAR lower than certain levels. The maximum normal tissue doses were decided 80%, 150%, 100%, 50% and 200% of the prescribed doses for the rectum, the urethra, the mandible, the skin and the large vessel, respectively. The doses to the metal markers using CTV-based dose prescription were generated. These were compared with the doses theoretically calculated with the Paris system. Treatment results were also investigated. The doses to the 158 metal markers (42 patients) for CTV were higher than ''tumoricidal dose''. In 7 patients, as a result of compromised dose prescription, 9 markers were lower than the tumoricidal dose. The other 12 markers (7%) were excluded from dose evaluation because they were judged as miss-implanted. The doses to the 142 metal markers (24 patients) for OAR were lower

  9. Impact of oedema on implant geometry and dosimetry for temporary high dose rate brachytherapy of the prostate

    International Nuclear Information System (INIS)

    Kiffer, J.D.; Schumer, W.A.; Mantle, C.A.; McKenzie, B.J.; Feigen, M.; Quong, G.G.; Waterman, F.M.

    2003-01-01

    The optimal timing of dosimetry for permanent seed prostatic implants remains contentious given the half life of post-implant oedema resolution. The aim of this study was to establish whether prostatic oedematous change over the duration of a temporary high dose rate (HDR) interstitial brachytherapy (BR) boost would result in significant needle displacement, and whether this change in geometry would influence dosimetry. Two CT scans, one for dosimetric purposes on the day of the implant and the second just prior to implant removal, were obtained for four patients receiving transperineal interstitial prostate brachytherapy. The relative changes in cross-sectional dimensions of the implants were calculated by establishing the change in mean radial distance (MRD) of the needle positions from the geometric centre of the implant for each patient's pair of CT studies. The treatment plan, as calculated from the first CT scan, was used in the second set of CT images to allow a comparison of dose distribution. The percentage change in MRD over the duration of the temporary implants ranged from -1.91% to 1.95%. The maximum change in estimated volume was 3.94%. Dosimetric changes were negligible. In the four cases studied, the degree of oedematous change and consequent displacement of flexiguide needle positions was negligible and did not impact on the dosimetry. The rate and direction of oedematous change can be extremely variable but on the basis of the four cases studied and the results of a larger recent study, it might not be necessary to re-image patients for dosimetric purposes over the duration of a fractionated HDR BT boost to the prostate where flexiguide needles are utilized. Nevertheless, further investigation with larger patient numbers is required. Copyright (2003) Blackwell Science Pty Ltd

  10. Dose to the Bladder Neck Is the Most Important Predictor for Acute and Late Toxicity After Low-Dose-Rate Prostate Brachytherapy: Implications for Establishing New Dose Constraints for Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Hathout, Lara; Folkert, Michael R.; Kollmeier, Marisa A.; Yamada, Yoshiya [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Cohen, Gil' ad N. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

    2014-10-01

    Purpose: To identify an anatomic structure predictive for acute (AUT) and late (LUT) urinary toxicity in patients with prostate cancer treated with low-dose-rate brachytherapy (LDR) with or without external beam radiation therapy (EBRT). Methods and Materials: From July 2002 to January 2013, 927 patients with prostate cancer (median age, 66 years) underwent LDR brachytherapy with Iodine 125 (n=753) or Palladium 103 (n=174) as definitive treatment (n=478) and as a boost (n=449) followed by supplemental EBRT (median dose, 50.4 Gy). Structures contoured on the computed tomographic (CT) scan on day 0 after implantation included prostate, urethra, bladder, and the bladder neck, defined as 5 mm around the urethra between the catheter balloon and the prostatic urethra. AUT and LUT were assessed with the Common Terminology Criteria for Adverse Events, version4. Clinical and dosimetric factors associated with AUT and LUT were analyzed with Cox regression and receiver operating characteristic analysis to calculate area under the receiver operator curve (ROC) (AUC). Results: Grade ≥2 AUT and grade ≥2 LUT occurred in 520 patients (56%) and 154 patients (20%), respectively. No grade 4 toxicities were observed. Bladder neck D2cc retained a significant association with AUT (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.03-1.04; P<.0001) and LUT (HR, 1.01; 95% CI, 1.00-1.03; P=.014) on multivariable analysis. In a comparison of bladder neck with the standard dosimetric variables by use of ROC analysis (prostate V100 >90%, D90 >100%, V150 >60%, urethra D20 >130%), bladder neck D2cc >50% was shown to have the strongest prognostic power for AUT (AUC, 0.697; P<.0001) and LUT (AUC, 0.620; P<.001). Conclusions: Bladder neck D2cc >50% was the strongest predictor for grade ≥2 AUT and LUT in patients treated with LDR brachytherapy. These data support inclusion of bladder neck constraints into brachytherapy planning to decrease urinary toxicity.

  11. Analysis of the high dose rate brachytherapy protocols of quality assurance programs of some local services, based on T G 40, T G 56 and ARCAL 30

    International Nuclear Information System (INIS)

    Guzman Calcina, Carmen S.; Almeida, Adelaide de; Rocha, Jose R. Oliveira; Universidade Estadual de Campinas, SP

    2001-01-01

    High dose rate brachytherapy has been increasingly recognized in most countries, and radiotherapy services using this equipment are encouraged to have a very efficient quality assurance program to ensure protection for patients, workers and other personnel involved. The objective of this paper was to determine the types of tests for high dose rate equipment required by official protocols (TG 40, TG 56 and ARCAL XXX) and to compare them with the types of tests utilized by some radiotherapy services. We concluded that: the protocol TG 56 is more extensive and complete than the other official protocols (T G 40 and ARCAL XXX); the protocols used by the services evaluated on this study were based on the protocol TG 56, and were concordant with the other official protocols. In these protocols annual tests were frequently replaced by tests performed quarterly or twice a year. This study established the types of test used and their frequency of utilization, and permitted the design of an optimized protocol that may help in the implementation of basic and indispensable tests in order to ensure patient adequate treatment and safety to personnel involved, and consequently improve high dose rate brachytherapy quality assurance. (author)

  12. Impact of using linear optimization models in dose planning for HDR brachytherapy

    International Nuclear Information System (INIS)

    Holm, Aasa; Larsson, Torbjoern; Carlsson Tedgren, Aasa

    2012-01-01

    Purpose: Dose plans generated with optimization models hitherto used in high-dose-rate (HDR) brachytherapy have shown a tendency to yield longer dwell times than manually optimized plans. Concern has been raised for the corresponding undesired hot spots, and various methods to mitigate these have been developed. The hypotheses upon this work is based are (a) that one cause for the long dwell times is the use of objective functions comprising simple linear penalties and (b) that alternative penalties, as these are piecewise linear, would lead to reduced length of individual dwell times. Methods: The characteristics of the linear penalties and the piecewise linear penalties are analyzed mathematically. Experimental comparisons between the two types of penalties are carried out retrospectively for a set of prostate cancer patients. Results: When the two types of penalties are compared, significant changes can be seen in the dwell times, while most dose-volume parameters do not differ significantly. On average, total dwell times were reduced by 4.2%, with a reduction of maximum dwell times by 25%, when the alternative penalties were used. Conclusions: The use of linear penalties in optimization models for HDR brachytherapy is one cause for the undesired long dwell times that arise in mathematically optimized plans. By introducing alternative penalties, a significant reduction in dwell times can be achieved for HDR brachytherapy dose plans. Although various measures for mitigating the long dwell times are already available, the observation that linear penalties contribute to their appearance is of fundamental interest.

  13. The dose distribution of low dose rate Cs-137 in intracavitary brachytherapy: comparison of Monte Carlo simulation, treatment planning calculation and polymer gel measurement

    International Nuclear Information System (INIS)

    Fragoso, M; Love, P A; Verhaegen, F; Nalder, C; Bidmead, A M; Leach, M; Webb, S

    2004-01-01

    In this study, the dose distribution delivered by low dose rate Cs-137 brachytherapy sources was investigated using Monte Carlo (MC) techniques and polymer gel dosimetry. The results obtained were compared with a commercial treatment planning system (TPS). The 20 mm and the 30 mm diameter Selectron vaginal applicator set (Nucletron) were used for this study. A homogeneous and a heterogeneous-with an air cavity-polymer gel phantom was used to measure the dose distribution from these sources. The same geometrical set-up was used for the MC calculations. Beyond the applicator tip, differences in dose as large as 20% were found between the MC and TPS. This is attributed to the presence of stainless steel in the applicator and source set, which are not considered by the TPS calculations. Beyond the air cavity, differences in dose of around 5% were noted, due to the TPS assuming a homogeneous water medium. The polymer gel results were in good agreement with the MC calculations for all the cases investigated

  14. Determining profile of dose distribution for PD-103 brachytherapy source

    International Nuclear Information System (INIS)

    Berkay, Camgoz; Mehmet, N. Kumru; Gultekin, Yegin

    2006-01-01

    Full text: Brachytherapy is a particular radiotherapy for cancer treatments. By destructing cancerous cells using radiation, the treatment proceeded. When alive tissues are subject it is hazardous to study experimental. For brachytherapy sources generally are studied as theoretical using computer simulation. General concept of the treatment is to locate the radioactive source into cancerous area of related tissue. In computer studies Monte Carlo mathematical method that is in principle based on random number generations, is used. Palladium radioisotope is LDR (Low radiation Dose Rate) source. Main radioactive material was coated with titanium cylinder with 3mm length, 0.25 mm radius. There are two parts of Pd-103 in the titanium cylinder. It is impossible to investigate differential effects come from two part as experimental. Because the source dimensions are small compared with measurement distances. So there is only simulation method. In dosimetric studies it is aimed to determine absorbed dose distribution in tissue as radial and angular. In nuclear physics it is obligation to use computer based methods for researchers. Radiation studies have hazards for scientist and people interacted with radiation. When hazard exceed over recommended limits or physical conditions are not suitable (long work time, non economical experiments, inadequate sensitivity of materials etc.) it is unavoidable to simulate works and experiments before practices of scientific methods in life. In medical area, usage of radiation is required computational work for cancer treatments. Some computational studies are routine in clinics and other studies have scientific development purposes. In brachytherapy studies there are significant differences between experimental measurements and theoretical (computer based) output data. Errors of data taken from experimental studies are larger than simulation values errors. In design of a new brachytherapy source it is important to consider detailed

  15. Vaginal tolerance of CT based image-guided high-dose rate interstitial brachytherapy for gynecological malignancies

    International Nuclear Information System (INIS)

    Murakami, Naoya; Inaba, Koji; Morota, Madoka; Ito, Yoshinori; Itami, Jun; Kasamatsu, Takahiro; Sumi, Minako; Yoshimura, Ryoichi; Harada, Ken; Kitaguchi, Mayuka; Sekii, Shuhei; Takahashi, Kana; Yoshio, Kotaro

    2014-01-01

    Purpose of this study was to identify predictors of vaginal ulcer after CT based three-dimensional image-guided high-dose-rate interstitial brachytherapy (HDR-ISBT) for gynecologic malignancies. Records were reviewed for 44 female (14 with primary disease and 30 with recurrence) with gynecological malignancies treated with HDR-ISBT with or without external beam radiation therapy. The HDR-ISBT applicator insertion was performed with image guidance by trans-rectal ultrasound and CT. The median clinical target volume was 35.5 ml (2.4-142.1 ml) and the median delivered dose in equivalent dose in 2 Gy fractions (EQD 2 ) for target volume D 90 was 67.7 Gy (48.8-94.2 Gy, doses of external-beam radiation therapy and brachytherapy were combined). For re-irradiation patients, median EQD 2 of D 2cc for rectum and bladder, D 0.5cc , D 1cc , D 2cc , D 4cc , D 6cc and D 8cc for vaginal wall was 91.1 Gy, 100.9 Gy, 260.3 Gy, 212.3 Gy, 170.1 Gy, 117.1 Gy, 105.2 Gy, and 94.7 Gy, respectively. For those without prior radiation therapy, median EQD 2 of D 2cc for rectum and bladder, D 0.5cc , D 1cc , D 2cc , D 4cc , D 6cc and D 8cc for vaginal wall was 56.3 Gy, 54.3 Gy, 147.4 Gy, 126.2 Gy, 108.0 Gy, 103.5 Gy, 94.7 Gy, and 80.7 Gy, respectively. Among five patients with vaginal ulcer, three had prior pelvic radiation therapy in their initial treatment and three consequently suffered from fistula formation. On univariate analysis, re-irradiation and vaginal wall D 2cc in EQD 2 was the clinical predictors of vaginal ulcer (p = 0.035 and p = 0.025, respectively). The ROC analysis revealed that vaginal wall D 2cc is the best predictor of vaginal ulcer. The 2-year incidence rates of vaginal ulcer in the patients with vaginal wall D 2cc in EQD 2 equal to or less than 145 Gy and over 145 Gy were 3.7% and 23.5%, respectively, with a statistically significant difference (p = 0.026). Re-irradiation and vaginal D 2cc is a significant predictor of vaginal ulcer after HDR-ISBT for gynecologic

  16. The use of high-dose-rate brachytherapy alone after lumpectomy in patients with early-stage breast cancer treated with breast-conserving therapy

    International Nuclear Information System (INIS)

    Baglan, Kathy L.; Martinez, Alvaro A.; Frazier, Robert C.; Kini, Vijay R.; Kestin, Larry L.; Chen, Peter Y.; Edmundson, Greg; Mele, Elizabeth; Jaffray, David; Vicini, Frank A.

    2001-01-01

    Purpose: We present the preliminary results of our in-house protocol using outpatient high-dose-rate (HDR) brachytherapy as the sole radiation modality following lumpectomy in patients with early-stage breast cancer. Methods and Materials: Thirty-seven patients with 38 Stage I-II breast cancers received radiation to the lumpectomy cavity alone using an HDR interstitial implant with 192 Ir. A minimum dose of 32 Gy was delivered on an outpatient basis in 8 fractions of 4 Gy to the lumpectomy cavity plus a 1- to 2-cm margin over consecutive 4 days. Results: Median follow-up is 31 months. There has been one ipsilateral breast recurrence for a crude failure rate of 2.6% and no regional or distant failures. Wound healing was not impaired in patients undergoing an open-cavity implant. Three minor breast infections occurred, and all resolved with oral antibiotics. The cosmetic outcome was good to excellent in all patients. Conclusion: In selected patients with early-stage breast cancer, treatment of the lumpectomy cavity alone with outpatient HDR brachytherapy is both technically feasible and well tolerated. Early results are encouraging, however, longer follow-up is necessary before equivalence to standard whole-breast irradiation can be established and to determine the most optimal radiation therapy technique to be employed

  17. High versus low dose rate intracavitary irradiation for adenocarcinoma of the uterine cervix

    International Nuclear Information System (INIS)

    Kim, Woo-Chul; Loh, John J.K.; Kim, Gwi-Eon; Suh, Chang-Ok

    2001-01-01

    Traditionally, low dose rate (LDR) brachytherapy has been used as a standard modality in the treatment of patients with carcinoma of the uterine cervix. The purpose of this work was to evaluate the effects of high dose rate (HDR) brachytherapy on patients with adenocarcinoma of the uterine cervix and to compare them with the effects of LDR brachytherapy. From January 1971 to December 1992, 104 patients suffering from adenocarcinoma of the uterine cervix were treated with radiation therapy in the Department of Radiation Oncology, Yonsei University. LDR brachytherapy was carried out on 34 patients and HDR brachytherapy on 70 patients. In the LDR group, eight patients were in stage IB, six in IIA, 12 in IIB, three in IIIA and five in IIIB. External radiation therapy was delivered with 10 MV X-rays, 2 Gy fraction per day, total dose of whole pelvis 36-52 Gy (median 46 Gy). LDR radium intracavitary irradiation was performed with a Henschke applicator, 37-59 Gy targeted at point A (median 43 Gy). In the HDR group, there were 16 patients in stage IB, six in IIA, 32 in IIB and 16 in IIIB. The total whole pelvis dose of external radiation was 40-50 Gy (median 44 Gy), daily 1.8-2.0 Gy. HDR Co-60 intracavitary irradiation was performed with a remotely controlled after-loading system (RALS), 30-48 Gy (median 39 Gy) targeted at point A, three times per week, 3 Gy per fraction. The 5-year overall survival rate in the LDR group was 72.9, 61.9 and 35.7% in stage I, II and III, respectively and the corresponding figures for HDR were 87.1, 58.3 and 43.8% (p 0.05). No prognostic factors were evident in the comparison between the two groups. There was no difference in terms of 5-year survival rate in the patients with adenocarcinoma of the uterine cervix between those treated with HDR and those treated with LDR brachytherapy. Even though late complication rates were higher in the HDR group, most of them were classified as grade I. This retrospective study suggests that HDR

  18. Volume and dose rate dependent (MDR-LDR Ir-192 afterloading interstitial brachytherapy) treatment optimisation, for squamouscell carcinoma of the lip

    International Nuclear Information System (INIS)

    Stas, Nathalie; Goncalves, Julieta; Pinho, Eliana; Trigo, Lurdes; Fernandes, Tome; Vieira, Elio

    1996-01-01

    Introduction: From 1/1/90 to 1/1/95, 53 patients with squamouscell carcinoma of the lip were treated by MDR or LDR Ir-192 afterloading interstitital brachytherapy. We compare the oncological and aesthetical results and sequelae depending on the volume and the dose rate. Material and methods: 53 patients, 41 men and 12 women, median age = 66y; 48 primary tumors (T1 = 26; T2 = 16; T3 = 6; N0 = 47; N1 = 1; M0 = 48) and 5 recurrencies; squamouscell carcinoma (grade 1 =45, g2 =6, g3 =2); clinical extension: buccal comissure=3, check =2, muscular =15, skin =7, lower and upper lip =1. Before radiotherapy, 28 biopsies and 25 excisional surgeries (19 with positive margins, 6 with negative margins) were performed. Brachytherapy was performed alone (dose 60-75 Gy BD85%) or as a boost (dose 10-30 Gy BD85%) associated with external beam (dose 46-50 Gy). MDR or LDR microselectron's afterloading was done after a computerised dosimetry (Paris System): treatment mean time = 30, 98 hours; mean volume = 10,2 cc (T1-T2 8, 61cc); Ir - 192 activity = range 0,7 - 4,792 mCi/cm; reference dose rate 45,6 - 290, 1 cGy/h. Results: 46 patients are alive without cancer, 1 died without responding, 6 died from non oncological diseases; 8 patients had recurrences (5 local, 3 nodal) but are alive. Mean follow-up 30,83 months (range 3-60m), mean DFS = 22,49 m (range 5-57m). Acute secondary effects: 30 radioepithelyties (grade 1 = 7, g2=23, g3=14), and 39 radiomucitis (g1=3; g2=23; g3=13); mean time for complete healing = 21, 66 days. Sequelae: moderate sclerosis of the skin =11, skin retraction = 1, hyperpigmentation2, depigmentation= 10, edema= 6, gingivitis= 7. Aesthetical results: good32; moderate= 18; bad= 2, very bad= 1 (uncontrolled tumor). Conclusions: The sequelae and aesthetical results are closely dependent on the treated volume and the dose rate, less dependent on the total dose, and independent on the Iridium activity. Complete healing time does not influence the late aesthetical results

  19. Time, dose and volume factors in interstitial brachytherapy combined with external irradiation for oral tongue carcinoma

    International Nuclear Information System (INIS)

    Yorozu, Atsunori

    1996-01-01

    This is a retrospective analysis of 136 patients with squamous cell carcinoma of stages I and II of the oral tongue who were treated with interstitial brachytherapy alone or in combination with external irradiation between 1976 and 1991. Control of the primary lesion and the occurrence of late complications were analyzed with respect to dose, time and tumor size with the Cox hazard model. The 5-year survival rates for stages I and II were 84.5% and 75.6%. The 5-year primary control rate was 91.3% for stage I and 77.3% for stage II (p 50 Gy compared with a brachytherapy dose 30 mm. Late complications should be reduced by using a spacer, improvements in dental and oral hygiene, and a sophisticated implant method. (author)

  20. A systematic evaluation of the dose-rate constant determined by photon spectrometry for 21 different models of low-energy photon-emitting brachytherapy sources.

    Science.gov (United States)

    Chen, Zhe Jay; Nath, Ravinder

    2010-10-21

    The aim of this study was to perform a systematic comparison of the dose-rate constant (Λ) determined by the photon spectrometry technique (PST) with the consensus value ((CON)Λ) recommended by the American Association of Physicists in Medicine (AAPM) for 21 low-energy photon-emitting interstitial brachytherapy sources. A total of 63 interstitial brachytherapy sources (21 different models with 3 sources per model) containing either (125)I (14 models), (103)Pd (6 models) or (131)Cs (1 model) were included in this study. A PST described by Chen and Nath (2007 Med. Phys. 34 1412-30) was used to determine the dose-rate constant ((PST)Λ) for each source model. Source-dependent variations in (PST)Λ were analyzed systematically against the spectral characteristics of the emitted photons and the consensus values recommended by the AAPM brachytherapy subcommittee. The values of (PST)Λ for the encapsulated sources of (103)Pd, (125)I and (131)Cs varied from 0.661 to 0.678 cGyh(-1) U(-1), 0.959 to 1.024 cGyh(-1)U(-1) and 1.066 to 1.073 cGyh(-1)U(-1), respectively. The relative variation in (PST)Λ among the six (103)Pd source models, caused by variations in photon attenuation and in spatial distributions of radioactivity among the source models, was less than 3%. Greater variations in (PST)Λ were observed among the 14 (125)I source models; the maximum relative difference was over 6%. These variations were caused primarily by the presence of silver in some (125)I source models and, to a lesser degree, by the variations in photon attenuation and in spatial distribution of radioactivity among the source models. The presence of silver generates additional fluorescent x-rays with lower photon energies which caused the (PST)Λ value to vary from 0.959 to 1.019 cGyh(-1)U(-1) depending on the amount of silver used by a given source model. For those (125)I sources that contain no silver, their (PST)Λ was less variable and had values within 1% of 1.024 cGyh(-1)U(-1). For the 16

  1. Real-time monitoring and verification of in vivo high dose rate brachytherapy using a pinhole camera

    International Nuclear Information System (INIS)

    Duan, Jun; Macey, Daniel J.; Pareek, Prem N.; Brezovich, Ivan A.

    2001-01-01

    We investigated a pinhole imaging system for independent in vivo monitoring and verification of high dose rate (HDR) brachytherapy treatment. The system consists of a high-resolution pinhole collimator, an x-ray fluoroscope, and a standard radiographic screen-film combination. Autofluoroscopy provides real-time images of the in vivo Ir-192 HDR source for monitoring the source location and movement, whereas autoradiography generates a permanent record of source positions on film. Dual-pinhole autoradiographs render stereo-shifted source images that can be used to reconstruct the source dwell positions in three dimensions. The dynamic range and spatial resolution of the system were studied with a polystyrene phantom using a range of source strengths and dwell times. For the range of source activity used in HDR brachytherapy, a 0.5 mm diameter pinhole produced sharp fluoroscopic images of the source within the dynamic range of the fluoroscope. With a source-to-film distance of 35 cm and a 400 speed screen-film combination, the same pinhole yielded well recognizable images of a 281.2 GBq (7.60 Ci) Ir-192 source for dwell times in the typical clinical range of 2 to 400 s. This 0.5 mm diameter pinhole could clearly resolve source positions separated by lateral displacements as small as 1 mm. Using a simple reconstruction algorithm, dwell positions in a phantom were derived from stereo-shifted dual-pinhole images and compared to the known positions. The agreement was better than 1 mm. A preliminary study of a patient undergoing HDR treatment for cervical cancer suggests that the imaging method is clinically feasible. Based on these studies we believe that the pinhole imaging method is capable of providing independent and reliable real-time monitoring and verification for HDR brachytherapy

  2. Health-Related Quality of Life After Single-Fraction High-Dose-Rate Brachytherapy and Hypofractionated External Beam Radiotherapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Morton, Gerard C.; Loblaw, D. Andrew; Chung, Hans; Tsang, Gail; Sankreacha, Raxa; Deabreu, Andrea; Zhang Liying; Mamedov, Alexandre; Cheung, Patrick; Batchelar, Deidre; Danjoux, Cyril; Szumacher, Ewa

    2011-01-01

    Purpose: To investigate the change in health-related quality of life for men after high-dose-rate brachytherapy and external beam radiotherapy for prostate cancer and the factors associated with this change. Methods and Materials: Eligible patients had clinically localized intermediate-risk prostate cancer. The patients received high-dose-rate brachytherapy as a single 15-Gy implant, followed by external beam radiotherapy to 37.5 Gy in 15 fractions. The patients were monitored prospectively for toxicity (Common Terminology Criteria for Adverse Events, version 3.0) and health-related quality of life (Expanded Prostate Cancer Index Composite [EPIC]). The proportion of patients developing a clinically significant difference in the EPIC domain score (minimally important difference of >0.5 standard deviation) was determined and correlated with the baseline clinical and dosimetric factors. The study accrued 125 patients, with a median follow-up of 24 months. Results: By 24 months, 23% had Grade 2 urinary toxicity and only 5% had Grade 2 bowel toxicity, with no Grade 3 toxicity. The proportion of patients reporting a significant decrease in EPIC urinary, bowel, sexual, and hormonal domain scores was 53%, 51%, 45%, and 40% at 12 months and 57%, 65%, 51%, and 30% at 24 months, respectively. The proportion with a >1 standard deviation decrease in the EPIC urinary, bowel, sexual, and hormonal domain scores was 38%, 36%, 24%, and 20% at 12 months and 46%, 48%, 19%, and 8% at 24 months, respectively. On multivariate analysis, the dose to 10% of the urethra was associated with a decreasing EPIC urinary domain score (p = .0089) and, less strongly (p = .0312) with a decreasing hormonal domain score. No association was found between the prostate volume, bladder dose, or high-dose volume and urinary health-related quality of life. A high baseline International Index of Erectile Function score was associated (p = .0019) with a decreasing sexual domain score. The optimal maximal dose

  3. Comparison of one and two low dose rate brachytherapy insertions in the treatment of stage IIB cervix cancer with radiation therapy alone

    International Nuclear Information System (INIS)

    Ferrigno, Robson; Faria, S.L.C.O.

    1996-01-01

    Purpose/Objective: To compare one and two intracavitary brachytherapy with low dose rate in the management of stage IIB cervix cancer through a prospective and randomized trial. Materials and Methods: From September 1989 to December 1992, 81 patients with stage IIB cervix cancer were randomized in two arms according to the number of intracavitary brachytherapy insertion to be realized. Of these, 34 were treated by two intracavitary insertions (group A) and 47 by one insertion (group B). The external beam radiotherapy (EBRT) was realized through a Cobalt unit at whole pelvis with total dose of 40Gy in 20 fractions of 2,0Gy, in box arrangement, followed by parametrial complementation of 10Gy. The brachytherapy was realized right after the end of EBRT. The patients from group A were underwent to two insertions of 25Gy, calculated at point A, defined by the Manchester system. The interval between each insertions was 2 weeks. The patients from group B were underwent to one insertion of 40 Gy at point A. The average dose rate was 60cGy per hour at point A. Results: With the follow up ranging from 36 to 75 months and medium of 55 months, the disease free survival of the patients from group A was not statistically different of those from group B, 70,6% and 72,3% respectively (p=0,711). Local recurrence occurred in four patients from group A (11,7%) and in eight from group B (17%). Distant metastasis occurred in one patient from group A (2,9%) and in two from group B (4,2%). Three patients from group A (8,8%) and three from group B (6,4%) were lost to follow up and considered as dead. The causes of death among patients from group A were progression of local disease in four, distant metastasis in one, complicated diabetes mellitus in one and actinic intestinal complications in other one. The cause of deaths among patients from group B were progression of local disease in eight and distant metastasis in two. The grade I and II rectal complications rate was 5,9% and 6,3% at

  4. Re-distribution of brachytherapy dose using a differential dose prescription adapted to risk of local failure in low-risk prostate cancer patients

    DEFF Research Database (Denmark)

    Rylander, Susanne; Polders, Daniel; Steggerda, Marcel J

    2015-01-01

    BACKGROUND AND PURPOSE: We investigated the application of a differential target- and dose prescription concept for low-dose-rate prostate brachytherapy (LDR-BT), involving a re-distribution of dose according to risk of local failure and treatment-related morbidity. MATERIAL AND METHODS: Our study......- and dose prescription concept of prescribing a lower dose to the whole gland and an escalated dose to the GTV using LDR-BT seed planning was technically feasible and resulted in a significant dose-reduction to urethra and bladder neck....

  5. Implementation of three-dimensional planning in brachytherapy of high dose rate for gynecology therapies; Implementacao de planejamento tridimensional em braquiterapia de alta taxa de dose para tratamentos ginecologicos

    Energy Technology Data Exchange (ETDEWEB)

    Sales, Camila Pessoa de

    2015-09-01

    This work aims to implement the three-dimensional (3D) planning for gynecological brachytherapy treatments. For this purpose, tests of acceptance and commissioning of brachytherapy equipment were performed to establish a quality and periodic assurance program. For this purpose, an important step was searching for a material to be used as a dummy source, since the applicators do not have any specific dummy. In addition, the validation of the use of applicators library was made for reconstruction in computed tomography (CT) and magnetic resonance imaging (MRI). In order to validate 3D planning, comparison of doses in dose assessment points used in bidimensional (2D) plans have been performed with volumetric doses to adjacent organs to the tumor. Finally, a protocol was established for 3D brachytherapy planning alternately using magnetic resonance image (MRI) and CT images, making evaluation of the dose in the tumor through the recording of MR and CT images. It was not possible to find a suitable material that could be used as dummy in MRI. However, the acquisition of the license's library for the applicators made possible the 3D planning based on MRI. No correlation was found between volumetric and specific doses analyzed, showing the importance of the implementation of 3D planning. The average ratio between D{sub 2cc} and ICRU{sub Bladder} dose was 1,74, 22% higher than the ratio found by others authors. For the rectum, D{sub 2cc} was less than dose point for 60% of fractions; the average difference was 12,5%. The average ratio between D{sub 2cc} and point dose rectum, 0,85, is equivalent to the value showed by Kim et al, 0,91. The D{sub 2cc} for sigmoid was 69% higher than point dose used, unless it was not possible compare this value, since the sigmoid point used in the 2D procedures is not used in others institutes. Relative dose in 2 cc of sigmoid was 57% of the prescription dose, the same value was found by in literature. This work enabled the

  6. Attenuation measurements show that the presence of a TachoSil surgical patch will not compromise target irradiation in intra-operative electron radiation therapy or high-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Sarmento, Sandra; Costa, Filipa; Pereira, Alexandre; Lencart, Joana; Dias, Anabela; Cunha, Luís; Sousa, Olga; Silva, José Pedro; Santos, Lúcio

    2015-01-01

    Surgery of locally advanced and/or recurrent rectal cancer can be complemented with intra-operative electron radiation therapy (IOERT) to deliver a single dose of radiation directly to the unresectable margins, while sparing nearby sensitive organs/structures. Haemorrhages may occur and can affect the dose distribution, leading to an incorrect target irradiation. The TachoSil (TS) surgical patch, when activated, creates a fibrin clot at the surgical site to achieve haemostasis. The aim of this work was to determine the effect of TS on the dose distribution, and ascertain whether it could be used in combination with IOERT. This characterization was extended to include high dose rate (HDR) intraoperative brachytherapy, which is sometimes used at other institutions instead of IOERT. CT images of the TS patch were acquired for initial characterization. Dosimetric measurements were performed in a water tank phantom, using a conventional LINAC with a hard-docking system of cylindrical applicators. Percentage Depth Dose (PDD) curves were obtained, and measurements made at the depth of dose maximum for the three clinically used electron energies (6, 9 and 12MeV), first without any attenuator and then with the activated patch of TS completely covering the tip of the IOERT applicator. For HDR brachytherapy, a measurement setup was improvised using a solid water phantom and a Farmer ionization chamber. Our measurements show that the attenuation of a TachoSil patch is negligible, both for high energy electron beams (6 to 12MeV), and for a HDR 192 Ir brachytherapy source. Our results cannot be extrapolated to lower beam energies such as 50 kVp X-rays, which are sometimes used for breast IORT. The TachoSil surgical patch can be used in IORT procedures using 6MeV electron energies or higher, or HDR 192 Ir brachytherapy

  7. Attenuation measurements show that the presence of a TachoSil surgical patch will not compromise target irradiation in intra-operative electron radiation therapy or high-dose-rate brachytherapy.

    Science.gov (United States)

    Sarmento, Sandra; Costa, Filipa; Pereira, Alexandre; Lencart, Joana; Dias, Anabela; Cunha, Luís; Sousa, Olga; Silva, José Pedro; Santos, Lúcio

    2015-01-09

    Surgery of locally advanced and/or recurrent rectal cancer can be complemented with intra-operative electron radiation therapy (IOERT) to deliver a single dose of radiation directly to the unresectable margins, while sparing nearby sensitive organs/structures. Haemorrhages may occur and can affect the dose distribution, leading to an incorrect target irradiation. The TachoSil (TS) surgical patch, when activated, creates a fibrin clot at the surgical site to achieve haemostasis. The aim of this work was to determine the effect of TS on the dose distribution, and ascertain whether it could be used in combination with IOERT. This characterization was extended to include high dose rate (HDR) intraoperative brachytherapy, which is sometimes used at other institutions instead of IOERT. CT images of the TS patch were acquired for initial characterization. Dosimetric measurements were performed in a water tank phantom, using a conventional LINAC with a hard-docking system of cylindrical applicators. Percentage Depth Dose (PDD) curves were obtained, and measurements made at the depth of dose maximum for the three clinically used electron energies (6, 9 and 12MeV), first without any attenuator and then with the activated patch of TS completely covering the tip of the IOERT applicator. For HDR brachytherapy, a measurement setup was improvised using a solid water phantom and a Farmer ionization chamber. Our measurements show that the attenuation of a TachoSil patch is negligible, both for high energy electron beams (6 to 12MeV), and for a HDR (192)Ir brachytherapy source. Our results cannot be extrapolated to lower beam energies such as 50 kVp X-rays, which are sometimes used for breast IORT. The TachoSil surgical patch can be used in IORT procedures using 6MeV electron energies or higher, or HDR (192)Ir brachytherapy.

  8. SU-F-T-32: Evaluation of the Performance of a Multiple-Array-Diode Detector for Quality Assurance Tests in High-Dose-Rate Brachytherapy with Ir-192 Source

    Energy Technology Data Exchange (ETDEWEB)

    Harpool, K; De La Fuente Herman, T; Ahmad, S; Ali, I [University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)

    2016-06-15

    Purpose: To evaluate the performance of a two-dimensional (2D) array-diode- detector for geometric and dosimetric quality assurance (QA) tests of high-dose-rate (HDR) brachytherapy with an Ir-192-source. Methods: A phantom setup was designed that encapsulated a two-dimensional (2D) array-diode-detector (MapCheck2) and a catheter for the HDR brachytherapy Ir-192 source. This setup was used to perform both geometric and dosimetric quality assurance for the HDR-Ir192 source. The geometric tests included: (a) measurement of the position of the source and (b) spacing between different dwell positions. The dosimteric tests include: (a) linearity of output with time, (b) end effect and (c) relative dose verification. The 2D-dose distribution measured with MapCheck2 was used to perform the previous tests. The results of MapCheck2 were compared with the corresponding quality assurance testes performed with Gafchromic-film and well-ionization-chamber. Results: The position of the source and the spacing between different dwell-positions were reproducible within 1 mm accuracy by measuring the position of maximal dose using MapCheck2 in contrast to the film which showed a blurred image of the dwell positions due to limited film sensitivity to irradiation. The linearity of the dose with dwell times measured from MapCheck2 was superior to the linearity measured with ionization chamber due to higher signal-to-noise ratio of the diode readings. MapCheck2 provided more accurate measurement of the end effect with uncertainty < 1.5% in comparison with the ionization chamber uncertainty of 3%. Although MapCheck2 did not provide absolute calibration dosimeter for the activity of the source, it provided accurate tool for relative dose verification in HDR-brachytherapy. Conclusion: The 2D-array-diode-detector provides a practical, compact and accurate tool to perform quality assurance for HDR-brachytherapy with an Ir-192 source. The diodes in MapCheck2 have high radiation sensitivity and

  9. Analysis of complications in a prospective randomized trial comparing two brachytherapy low dose rates in cervical carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-07-30

    The analysis of complications in a prospective randomized trial comparing two preoperative brachytherapy low-dose rates in early stage cervical cancer is presented. The objective of this trial was to determine the benefits, if any, of the higher-dose rate within the therapeutic aresenal for this patient population, in terms of survival, local control, and complications. Overall survival, 85% at 2 years and local control, 93% at 2 years, were similarly distributed between the two groups. Regardless of their nature and severity, 139 and 175 complications were observed among 63% and 75% of patients, in the 0.4 and 0.8 Gy/h dose rate groups respectively. Gynecologic and urinary complications were the most frequent (38% and 28% of all complications), followed by vascular (15%), digestive (10%), nervous (5%), and cutaneous (5%). A total of 14 and 17 severe complications (Grade 3) were observed in 7% and 13% of patients, respectively in the 0.4 and 0.8 Gy/h dose rate groups (p = 0.12) Nonparametric survival methods used to compare the time to the first complication did not show a significant difference between the two groups: 62% and 72% at 2 years (p = 0.27). When the first complication and its evolution were considered (early complications), the prevalence of complications was not significantly different between the two groups: 28% vs. 34% at 2 years (p = 0.31). In this prospective trial, patients were regularly followed-up and complications of varying nature and severity were observed in succession during follow-up. When successive complications and their evolution were taken into account, the prevalence of complications was significantly greater in the higher-dose rate group: 30% vs 45% at 2 years (p = 0.03). The results of this trial showed that long-term effects of treatment, when represented by prevalence of complications over time, were more frequent in the higher dose rate group. 33 refs., 3 figs., 5 tabs.

  10. SU-G-201-06: Directional Low-Dose Rate Brachytherapy: Determination of the TG-43 Dose-Rate Constant Analog for a New Pd-103 Source

    Energy Technology Data Exchange (ETDEWEB)

    Aima, M; Culberson, W; Hammer, C; Micka, J; DeWerd, L [Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI (United States)

    2016-06-15

    Purpose: The aim of this work is to determine the TG-43 dose-rate constant analog for a new directional low-dose rate brachytherapy source based on experimental methods and comparison to Monte Carlo simulations. The CivaSheet™ is a new commercially available planar source array comprised of a variable number of discrete directional source elements called “CivaDots”. Given the directional nature and non-conventional design of the source, modifications to the AAPM TG-43 protocol for dosimetry are required. As a result, various parameters of the TG-43 dosimetric formalism have to be adapted to accommodate this source. This work focuses on the dose-rate constant analog determination for a CivaDot. Methods: Dose to water measurements of the CivaDot were performed in a polymethyl methacrylate phantom (20×20×12 cm{sup 3}) using thermoluminescent dosimeters (TLDs) and Gafchromic EBT3 film. The source was placed in the center of the phantom, and nine TLD micro-cubes were irradiated along its central axis at a distance of 1 cm. For the film measurements, the TLDs were substituted by a (3×3) cm{sup 2} EBT3 film. Primary air-kerma strength measurements of the source were performed using a variable-aperture free-air chamber. Finally, the source was modeled using the Monte Carlo N-Particle Transport Code 6. Results: Dose-rate constant analog observed for a total of eight CivaDots using TLDs and five CivaDots using EBT3 film was within ±7.0% and ±2.9% of the Monte Carlo predicted value respectively. The average difference observed was −4.8% and −0.1% with a standard deviation of 1.7% and 2.1% for the TLD and the film measurements respectively, which are both within the comparison uncertainty. Conclusion: A preliminary investigation to determine the doserate constant analog for a CivaDot was conducted successfully with good agreement between experimental and Monte Carlo based methods. This work will aid in the eventual realization of a clinically-viable dosimetric

  11. Improved tissue assignment using dual-energy computed tomography in low-dose rate prostate brachytherapy for Monte Carlo dose calculation

    Energy Technology Data Exchange (ETDEWEB)

    Côté, Nicolas [Département de Physique, Université de Montréal, Pavillon Roger-Gaudry (D-428), 2900 Boulevard Édouard-Montpetit, Montréal, Québec H3T 1J4 (Canada); Bedwani, Stéphane [Département de Radio-Oncologie, Centre Hospitalier de l’Université de Montréal (CHUM), 1560 Rue Sherbrooke Est, Montréal, Québec H2L 4M1 (Canada); Carrier, Jean-François, E-mail: jean-francois.carrier.chum@ssss.gouv.qc.ca [Département de Physique, Université de Montréal, Pavillon Roger-Gaudry (D-428), 2900 Boulevard Édouard-Montpetit, Montréal, Québec H3T 1J4, Canada and Département de Radio-Oncologie, Centre Hospitalier de l’Université de Montréal (CHUM), 1560 Rue Sherbrooke Est, Montréal, Québec H2L 4M1 (Canada)

    2016-05-15

    Purpose: An improvement in tissue assignment for low-dose rate brachytherapy (LDRB) patients using more accurate Monte Carlo (MC) dose calculation was accomplished with a metallic artifact reduction (MAR) method specific to dual-energy computed tomography (DECT). Methods: The proposed MAR algorithm followed a four-step procedure. The first step involved applying a weighted blend of both DECT scans (I {sub H/L}) to generate a new image (I {sub Mix}). This action minimized Hounsfield unit (HU) variations surrounding the brachytherapy seeds. In the second step, the mean HU of the prostate in I {sub Mix} was calculated and shifted toward the mean HU of the two original DECT images (I {sub H/L}). The third step involved smoothing the newly shifted I {sub Mix} and the two original I {sub H/L}, followed by a subtraction of both, generating an image that represented the metallic artifact (I {sub A,(H/L)}) of reduced noise levels. The final step consisted of subtracting the original I {sub H/L} from the newly generated I {sub A,(H/L)} and obtaining a final image corrected for metallic artifacts. Following the completion of the algorithm, a DECT stoichiometric method was used to extract the relative electronic density (ρ{sub e}) and effective atomic number (Z {sub eff}) at each voxel of the corrected scans. Tissue assignment could then be determined with these two newly acquired physical parameters. Each voxel was assigned the tissue bearing the closest resemblance in terms of ρ{sub e} and Z {sub eff}, comparing with values from the ICRU 42 database. A MC study was then performed to compare the dosimetric impacts of alternative MAR algorithms. Results: An improvement in tissue assignment was observed with the DECT MAR algorithm, compared to the single-energy computed tomography (SECT) approach. In a phantom study, tissue misassignment was found to reach 0.05% of voxels using the DECT approach, compared with 0.40% using the SECT method. Comparison of the DECT and SECT D

  12. Clinical application of a OneDose MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast.

    Science.gov (United States)

    Kinhikar, Rajesh A; Sharma, Pramod K; Tambe, Chandrashekhar M; Mahantshetty, Umesh M; Sarin, Rajiv; Deshpande, Deepak D; Shrivastava, Shyam K

    2006-07-21

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs.

  13. Economic assessment of pulsed dose-rate (P.D.R.) brachytherapy with optimized dose distribution for cervix carcinoma;Evaluation economique de la curietherapie de debit pulse gynecologique (PDR) avec optimisation de la dose pour les cancers du col uterin

    Energy Technology Data Exchange (ETDEWEB)

    Remonnay, R.; Morelle, M.; Pommier, P.; Carrere, M.O. [Lyon Univ., 69 (France); Remonnay, R.; Morelle, M.; Pommier, P. [Axe Economie de la Sante, GATE, CNRS-UMR 5824, Centre Leon-Berard, 69 - Lyon (France); Pommier, P. [Centre Leon-Berard, 69 - Lyon (France); Haie-Meder, C. [Institut Gustave-Roussy, 94 - Villejuif (France); Quetin, P. [Centre Paul-Strauss, 67 - Strasbourg (France); Kerr, C. [Centre Val-d' Aurelle, parc Euromedecine, 34 - Montpellier (France); Delannes, M. [Institut Claudius-Regaud, 31 - Toulouse (France); Castelain, B. [Centre Oscar-Lambret, 59 - Lille (France); Peignaux, K. [Centre Georges Francois Leclerc, 21 - Dijon (France); Kirova, Y. [Institut Curie, 75 - Paris (France); Romestaing, P. [Centre hospitalier Lyon Sud, 69 - Pierre-Benite (France); Williaume, D. [Centre Eugene-Marquis, 35 - Rennes (France); Krzisch, C. [Hopital Sud, 80 - Amiens (France); Thomas, L. [Institut Bergonie, 33 - Bordeaux (France); Lang, P. [Groupe hospitalier Pitie-Salpetriere, 75 - Paris (France); Baron, M.H. [Hopital Jean-Minjoz, 25 - Besancon (France); Cussac, A. [Centre Rene-Gauducheau, 44 - Nantes-Saint-Herblain (France); Lesaunier, F. [Centre Francois-Baclesse, 14 - Caen (France); Maillard, S. [Institut Jean-Godinot, 51 - Reims (France); Barillot, I. [Hopital Bretonneau, 37 - Tours (France); Charra-Brunaud, C.; Peiffert, D. [Centre Alexis-Vautrin, 54 - Vandoeuvre-les-Nancy (France)

    2010-06-15

    Purpose: Our study aims at evaluating the cost of pulsed dose-rate (P.D.R.) brachytherapy with optimized dose distribution versus traditional treatments (iridium wires, cesium, non-optimized P.D.R.). Issues surrounding reimbursement were also explored. Materials and methods: This prospective, multi-centre, non-randomized study conducted in the framework of a project entitled 'Support Program for Costly Diagnostic and Therapeutic Innovations' involved 21 hospitals. Patients with cervix carcinoma received either classical brachytherapy or the innovation. The direct medical costs of staff and equipment, as well as the costs of radioactive sources, consumables and building renovation were evaluated from a hospital point of view using a micro costing approach. Subsequent costs per brachytherapy were compared between the four strategies. Results: The economic study included 463 patients over two years. The main resources categories associated with P.D.R. brachytherapy (whether optimized or not) were radioactive sources (1053 Euros) and source projectors (735 Euros). Optimized P.D.R. induced higher cost of imagery and dosimetry (respectively 130 Euros and 367 Euros) than non-optimized P.D.R. (47 Euros and 75 Euros). Extra costs of innovation over the less costly strategy (iridium wires) reached more than 2100 Euros per treatment, but could be reduced by half in the hypothesis of 40 patients treated per year (instead of 24 in the study). Conclusion: Aside from staff, imaging and dosimetry, the current hospital reimbursements largely underestimated the cost of innovation related to equipment and sources. (authors)

  14. A new applicator design for endocavitary brachytherapy of cancer in the nasopharynx

    International Nuclear Information System (INIS)

    Levendag, Peter C.; Peters, Rob; Meeuwis, Cees A.; Visch, Leo L.; Sipkema, Dick; Pan, Connie de; Schmitz, Paul I.M.

    1997-01-01

    Introduction: In attempting to improve local tumor control by higher doses of radiation, there has been a resurgence of interest in the implementation of brachytherapy in the management of primary and recurrent cancers of the nasopharynx. Brachytherapy with its steep dose fall-off is of particular interest because of the proximity of critical dose limiting structures. Recent developments in brachytherapy, such as the introduction of pulsed-dose-rate and high-dose-rate computerized afterloaders, have encouraged further evolution of brachytherapy techniques. Materials and methods: We have designed an inexpensive, re-usable and flexible silicone applicator, tailored to the shape of the soft tissues of the nasopharynx, which can be used with either low-dose-rate brachytherapy or high (pulsed)-dose-rate remote controlled afterloaders. Results and conclusions: This Rotterdam nasopharynx applicator proved to be easy to introduce, patient friendly and can remain in situ for the duration of the treatment (2-6 days). The design, technique of application and the first consecutive 5 years of clinical experience in using this applicator are presented

  15. The difference of scoring dose to water or tissues in Monte Carlo dose calculations for low energy brachytherapy photon sources.

    Science.gov (United States)

    Landry, Guillaume; Reniers, Brigitte; Pignol, Jean-Philippe; Beaulieu, Luc; Verhaegen, Frank

    2011-03-01

    The goal of this work is to compare D(m,m) (radiation transported in medium; dose scored in medium) and D(w,m) (radiation transported in medium; dose scored in water) obtained from Monte Carlo (MC) simulations for a subset of human tissues of interest in low energy photon brachytherapy. Using low dose rate seeds and an electronic brachytherapy source (EBS), the authors quantify the large cavity theory conversion factors required. The authors also assess whether ap plying large cavity theory utilizing the sources' initial photon spectra and average photon energy induces errors related to spatial spectral variations. First, ideal spherical geometries were investigated, followed by clinical brachytherapy LDR seed implants for breast and prostate cancer patients. Two types of dose calculations are performed with the GEANT4 MC code. (1) For several human tissues, dose profiles are obtained in spherical geometries centered on four types of low energy brachytherapy sources: 125I, 103Pd, and 131Cs seeds, as well as an EBS operating at 50 kV. Ratios of D(w,m) over D(m,m) are evaluated in the 0-6 cm range. In addition to mean tissue composition, compositions corresponding to one standard deviation from the mean are also studied. (2) Four clinical breast (using 103Pd) and prostate (using 125I) brachytherapy seed implants are considered. MC dose calculations are performed based on postimplant CT scans using prostate and breast tissue compositions. PTV D90 values are compared for D(w,m) and D(m,m). (1) Differences (D(w,m)/D(m,m)-1) of -3% to 70% are observed for the investigated tissues. For a given tissue, D(w,m)/D(m,m) is similar for all sources within 4% and does not vary more than 2% with distance due to very moderate spectral shifts. Variations of tissue composition about the assumed mean composition influence the conversion factors up to 38%. (2) The ratio of D90(w,m) over D90(m,m) for clinical implants matches D(w,m)/D(m,m) at 1 cm from the single point sources, Given

  16. Dose mapping of the rectal wall during brachytherapy with an array of scintillation dosimeters

    International Nuclear Information System (INIS)

    Cartwright, L. E.; Suchowerska, N.; Yin, Y.; Lambert, J.; Haque, M.; McKenzie, D. R.

    2010-01-01

    Purpose: In pelvic brachytherapy treatments, the rectum is an organ at risk. The authors have developed an array of scintillation dosimeters suitable for in vivo use that enables quality assurance of the treatment delivery and provides an alert to potential radiation accidents. Ultimately, this will provide evidence to direct treatment planning and dose escalation and correlate dose with the rectal response. Methods: An array of 16 scintillation dosimeters in an insertable applicator has been developed. The dosimeters were calibrated simultaneously in a custom designed circular jig before use. Each dosimeter is optically interfaced to a set of pixels on a CCD camera located outside the treatment bunker. A customized software converts pixel values into dose rate and accumulates dose for presentation during treatment delivery. The performance of the array is tested by simulating brachytherapy treatments in a water phantom. The treatment plans were designed to deliver a known dose distribution on the surface of the rectal applicator, assumed to represent the dose to the rectal wall. Results: The measured doses were compared to those predicted by the treatment plan and found to be in agreement to within the uncertainty in measurement, usually within 3%. The array was also used to track the progression of the source as it moved along the catheter. The measured position was found to agree with the position reported by the afterloader to within the measurement uncertainty, usually within 2 mm. Conclusions: This array is capable of measuring the actual dose received by each region of the rectal wall during brachytherapy treatments. It will provide real time monitoring of treatment delivery and raise an alert to a potential radiation accident. Real time dose mapping in the clinical environment will give the clinician additional confidence to carry out dose escalation to the tumor volume while avoiding rectal side effects.

  17. The Effect of Dose and Quality Assurance in Early Prostate Cancer Treated with Low Dose Rate Brachytherapy as Monotherapy.

    Science.gov (United States)

    Henry, A M; Rodda, S L; Mason, M; Musunuru, H; Al-Qaisieh, B; Bownes, P; Smith, J; Franks, K; Carey, B; Bottomley, D

    2015-07-01

    To examine the relationship between post-implant computed tomography dosimetry and long-term prostate-specific antigen relapse-free survival in patients treated with iodine 125 (I-125) low dose rate prostate brachytherapy as monotherapy and, second, to audit recent practice against Royal College of Radiologists' (RCR) guidelines after the re-introduction of post-implant dosimetry for all patients in our centre. Between March 1995 and September 2007, 2157 consecutive patients with localised prostate cancer underwent I-125 permanent prostate brachytherapy as monotherapy in a single UK centre. All patients were transrectal ultrasound planned delivering a 145 Gy (TG 43) minimum peripheral dose. None received supplemental external beam radiotherapy. Post-implant computed tomography-based dosimetry was undertaken between 4 and 6 weeks after treatment and was available for 711 (33%). Outcomes were analysed in terms of the relationship of D90 to prostate-specific antigen relapse-free survival (nadir 2+ definition) and all patients had a minimum follow-up of 5 years. For contemporary patients from 2011, quality metrics from post-implant computed tomography as defined by RCR guidelines are presented. A mean D90 of 138.7 Gy (standard deviation 24.7) was achieved for the historic cohort. Biochemical control at 10 years was 76% in patients with D90 > 140 Gy and 68% in those with D90 standard deviation) D90 has increased from 154 (15.3) Gy in 2011 to 164 (13.5) Gy in 2013. Similarly, an increase in the mean (standard deviation) V100 from 92 (4.4) to 95 (3.2) % is noted over time. No difference between clinicians was noted. D90 values of less than 140 Gy continue to be predictive of increased risk of recurrence of prostate cancer across risk groups with longer follow-up. Quality assurance can be used to ensure improved and consistent implant quality in a team with multiple clinicians. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights

  18. An analysis of acute complications and perioperative morbidity from high dose rate brachytherapy in the treatment of gynecological malignancies

    International Nuclear Information System (INIS)

    Sarkaria, Jann N.; Petereit, Daniel G.; Kinsella, Timothy J.; Buchler, Dolores A.

    1995-01-01

    Purpose: To evaluate the acute morbidity and mortality for high dose-rate (HDR) brachytherapy performed in an outpatient setting in the treatment of gynecological malignancies, and to identify possible risk factors for adverse outcomes. Materials and Methods: One hundred seventy-one patients with cervical (n=129) or uterine (n=42) carcinoma with an intact uterus were evaluated and treated from August 1989 through December 1994, with at least part of their therapy delivered with intracavitary HDR 192 Ir radiation. A total of 830 ICR insertions were performed with greater than 95% done on an outpatient basis under heavy intravenous sedation using fentanyl and midazolam. Perioperative morbidity and mortality were recorded for any event occurring within 30 days of the completion of therapy. Anesthesia risk was evaluated retrospectively in all patients based on the American Society of Anesthesiologists' (ASA) Physical Class System. Results: The uterine patients, many treated with radiation alone because of morbid obesity or medical inoperability, had a significantly higher perioperative morbidity and mortality rate as compared to the cervix patient cohort. Thirteen of the 42 (31%) uterine patients and 8 of the 129 (6%) cervix patients required hospitalization within 30 days of treatment completion (p 2) experienced greater morbidity and mortality, while the best predictor of complications in the cervix patients was age greater than 70 years. For the entire cohort of patients, no correlation was found between the 30 day morbidity and mortality and the doses of fentanyl and midazolam used or the length of the procedure. Conclusions: The acute complication rate from HDR brachytherapy performed on an outpatient basis with heavy intravenous sedation is acceptable for the great majority of patients who present for treatment. However, the high morbidity and mortality experienced by certain patient cohorts suggests that careful assessment of the risk/benefit ratio for treatment

  19. A non-rigid point matching method with local topology preservation for accurate bladder dose summation in high dose rate cervical brachytherapy.

    Science.gov (United States)

    Chen, Haibin; Zhong, Zichun; Liao, Yuliang; Pompoš, Arnold; Hrycushko, Brian; Albuquerque, Kevin; Zhen, Xin; Zhou, Linghong; Gu, Xuejun

    2016-02-07

    GEC-ESTRO guidelines for high dose rate cervical brachytherapy advocate the reporting of the D2cc (the minimum dose received by the maximally exposed 2cc volume) to organs at risk. Due to large interfractional organ motion, reporting of accurate cumulative D2cc over a multifractional course is a non-trivial task requiring deformable image registration and deformable dose summation. To efficiently and accurately describe the point-to-point correspondence of the bladder wall over all treatment fractions while preserving local topologies, we propose a novel graphic processing unit (GPU)-based non-rigid point matching algorithm. This is achieved by introducing local anatomic information into the iterative update of correspondence matrix computation in the 'thin plate splines-robust point matching' (TPS-RPM) scheme. The performance of the GPU-based TPS-RPM with local topology preservation algorithm (TPS-RPM-LTP) was evaluated using four numerically simulated synthetic bladders having known deformations, a custom-made porcine bladder phantom embedded with twenty one fiducial markers, and 29 fractional computed tomography (CT) images from seven cervical cancer patients. Results show that TPS-RPM-LTP achieved excellent geometric accuracy with landmark residual distance error (RDE) of 0.7  ±  0.3 mm for the numerical synthetic data with different scales of bladder deformation and structure complexity, and 3.7  ±  1.8 mm and 1.6  ±  0.8 mm for the porcine bladder phantom with large and small deformation, respectively. The RDE accuracy of the urethral orifice landmarks in patient bladders was 3.7  ±  2.1 mm. When compared to the original TPS-RPM, the TPS-RPM-LTP improved landmark matching by reducing landmark RDE by 50  ±  19%, 37  ±  11% and 28  ±  11% for the synthetic, porcine phantom and the patient bladders, respectively. This was achieved with a computational time of less than 15 s in all cases

  20. Direction-Modulated Brachytherapy for High-Dose-Rate Treatment of Cervical Cancer. I: Theoretical Design

    International Nuclear Information System (INIS)

    Han, Dae Yup; Webster, Matthew J.; Scanderbeg, Daniel J.; Yashar, Catheryn; Choi, Dongju; Song, Bongyong; Devic, Slobodan; Ravi, Ananth; Song, William Y.

    2014-01-01

    Purpose: To demonstrate that utilization of the direction-modulated brachytherapy (DMBT) concept can significantly improve treatment plan quality in the setting of high-dose-rate (HDR) brachytherapy for cervical cancer. Methods and Materials: The new, MRI-compatible, tandem design has 6 peripheral holes of 1.3-mm diameter, grooved along a nonmagnetic tungsten-alloy rod (ρ = 18.0 g/cm 3 ), enclosed in Delrin tubing (polyoxymethylene, ρ = 1.41 g/cm 3 ), with a total thickness of 6.4 mm. The Monte Carlo N-Particle code was used to calculate the anisotropic 192 Ir dose distributions. An in-house-developed inverse planning platform, geared with simulated annealing and constrained-gradient optimization algorithms, was used to replan 15 patient cases (total 75 plans) treated with a conventional tandem and ovoids (T and O) applicator. Prescription dose was 6 Gy. For replanning, we replaced the conventional tandem with that of the new DMBT tandem for optimization but left the ovoids in place and kept the dwell positions as originally planned. All DMBT plans were normalized to match the high-risk clinical target volume V100 coverage of the T and O plans. Results: In general there were marked improvements in plan quality for the DMBT plans. On average, D2cc for the bladder, rectum, and sigmoid were reduced by 0.59 ± 0.87 Gy (8.5% ± 28.7%), 0.48 ± 0.55 Gy (21.1% ± 27.2%), and 0.10 ± 0.38 Gy (40.6% ± 214.9%) among the 75 plans, with best single-plan reductions of 3.20 Gy (40.8%), 2.38 Gy (40.07%), and 1.26 Gy (27.5%), respectively. The high-risk clinical target volume D90 was similar, with 6.55 ± 0.96 Gy and 6.59 ± 1.06 Gy for T and O and DMBT, respectively. Conclusions: Application of the DMBT concept to cervical cancer allowed for improved organ at risk sparing while achieving similar target coverage on a sizeable patient population, as intended, by maximally utilizing the anatomic information contained in 3-dimensional imaging. A

  1. Calculation of integrated biological response in brachytherapy

    International Nuclear Information System (INIS)

    Dale, Roger G.; Coles, Ian P.; Deehan, Charles; O'Donoghue, Joseph A.

    1997-01-01

    Purpose: To present analytical methods for calculating or estimating the integrated biological response in brachytherapy applications, and which allow for the presence of dose gradients. Methods and Materials: The approach uses linear-quadratic (LQ) formulations to identify an equivalent biologically effective dose (BED eq ) which, if applied to a specified tissue volume, would produce the same biological effect as that achieved by a given brachytherapy application. For simple geometrical cases, BED multiplying factors have been derived which allow the equivalent BED for tumors to be estimated from a single BED value calculated at a dose reference point. For more complex brachytherapy applications a voxel-by-voxel determination of the equivalent BED will be more accurate. Equations are derived which when incorporated into brachytherapy software would facilitate such a process. Results: At both high and low dose rates, the BEDs calculated at the dose reference point are shown to be lower than the true values by an amount which depends primarily on the magnitude of the prescribed dose; the BED multiplying factors are higher for smaller prescribed doses. The multiplying factors are less dependent on the assumed radiobiological parameters. In most clinical applications involving multiple sources, particularly those in multiplanar arrays, the multiplying factors are likely to be smaller than those derived here for single sources. The overall suggestion is that the radiobiological consequences of dose gradients in well-designed brachytherapy treatments, although important, may be less significant than is sometimes supposed. The modeling exercise also demonstrates that the integrated biological effect associated with fractionated high-dose-rate (FHDR) brachytherapy will usually be different from that for an 'equivalent' continuous low-dose-rate (CLDR) regime. For practical FHDR regimes involving relatively small numbers of fractions, the integrated biological effect to

  2. SU-E-T-10: A Clinical Implementation and the Dosimetric Evidence in High Dose Rate Vaginal Multichannel Applicator Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Syh, J; Syh, J; Patel, B; Zhang, J; Wu, H; Rosen, L [Willis-Knighton Medical Center, Shreveport, LA (United States)

    2015-06-15

    Purpose: The multichannel cylindrical applicator has a distinctive modification of the traditional single channel cylindrical applicator. The novel multichannel applicator has additional peripheral channels that provide more flexibility both in treatment planning process and outcomes. To protect by reducing doses to adjacent organ at risk (OAR) while maintaining target coverage with inverse plan optimization are the goals for such novel Brachytherapy device. Through a series of comparison and analysis of reults in more than forty patients who received HDR Brachytherapy using multichannel vaginal applicator, this procedure has been implemented in our institution. Methods: Multichannel planning was CT image based. The CTV of 5mm vaginal cuff rind with prescribed length was well reconstructed as well as bladder and rectum. At least D95 of CTV coverage is 95% of prescribed dose. Multichannel inverse plan optimization algorithm not only shapes target dose cloud but set dose avoids to OAR’s exclusively. The doses of D2cc, D5cc and D5; volume of V2Gy in OAR’s were selected to compare with single channel results when sole central channel is only possibility. Results: Study demonstrates plan superiorly in OAR’s doe reduction in multi-channel plan. The D2cc of the rectum and bladder were showing a little lower for multichannel vs. single channel. The V2Gy of the rectum was 93.72% vs. 83.79% (p=0.007) for single channel vs. multichannel respectively. Absolute reduced mean dose of D5 by multichannel was 17 cGy (s.d.=6.4) and 44 cGy (s.d.=15.2) in bladder and rectum respectively. Conclusion: The optimization solution in multichannel was to maintain D95 CTV coverage while reducing the dose to OAR’s. Dosimetric advantage in sparing critical organs by using a multichannel applicator in HDR Brachytherapy treatment of the vaginal cuff is so promising and has been implemented clinically.

  3. Anatomy-based inverse optimization in high-dose-rate brachytherapy combined with hypofractionated external beam radiotherapy for localized prostate cancer: Comparison of incidence of acute genitourinary toxicity between anatomy-based inverse optimization and geometric optimization

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Katoh, Hiroyuki; Kitamoto, Yoshizumi; Shirai, Katsuyuki; Shioya, Mariko; Nakano, Takashi

    2006-01-01

    Purpose: To evaluate the advantages of anatomy-based inverse optimization (IO) in planning high-dose-rate (HDR) brachytherapy. Methods and Materials: A total of 114 patients who received HDR brachytherapy (9 Gy in two fractions) combined with hypofractionated external beam radiotherapy (EBRT) were analyzed. The dose distributions of HDR brachytherapy were optimized using geometric optimization (GO) in 70 patients and by anatomy-based IO in the remaining 44 patients. The correlation between the dose-volume histogram parameters, including the urethral dose and the incidence of acute genitourinary (GU) toxicity, was evaluated. Results: The averaged values of the percentage of volume receiving 80-150% of the prescribed minimal peripheral dose (V 8 -V 15 ) of the urethra generated by anatomy-based IO were significantly lower than the corresponding values generated by GO. Similarly, the averaged values of the minimal dose received by 5-50% of the target volume (D 5 -D 5 ) obtained using anatomy-based IO were significantly lower than those obtained using GO. Regarding acute toxicity, Grade 2 or worse acute GU toxicity developed in 23% of all patients, but was significantly lower in patients for whom anatomy-based IO (16%) was used than in those for whom GO was used (37%), consistent with the reduced urethral dose (p <0.01). Conclusion: The results of this study suggest that anatomy-based IO is superior to GO for dose optimization in HDR brachytherapy for prostate cancer

  4. Intraoperative high-dose-rate brachytherapy for the treatment of pediatric tumors: the Ohio State University experience

    International Nuclear Information System (INIS)

    Nag, Subir; Tippin, Douglas; Ruymann, Frederick B.

    2001-01-01

    Purpose: To determine whether intraoperative high-dose-rate brachytherapy (IO-HDRBT) can be used to decrease the dose of external beam radiotherapy (EBRT) in the treatment of children with soft-tissue sarcomas and, thereby, reduce morbidity without compromising local control. Methods and Materials: From March 1992 through April 1999, 13 pediatric patients were treated with IO-HDRBT, low-dose EBRT, chemotherapy, and radical surgery at 21 sites that were not amenable to intraoperative electron beam therapy. The IO-HDRBT dose at 5 mm depth was 10 to 12.5 Gy for close margins/microscopic disease at 14 sites and 12.5 to 15 Gy for gross disease at 7 sites. The treatment volumes ranged from 4 to 96 cm 3 (mean 27). The EBRT dose was limited to 27-30 Gy in most cases to minimize growth retardation and preserve normal organ function. Results: After a median follow-up of 47 months (range 12-97), 11 patients were alive and without evidence of disease (overall survival rate 85%, 4-year actuarial survival rate 77%). Of the 2 who died, 1 had Stage III pulmonary blastoma with a sacral recurrence; the other had Stage IV undifferentiated synovial sarcoma with a pulmonary recurrence. One local failure occurred in a patient with gross residual disease after incomplete resection for Stage IV pulmonary blastoma. The local control rate was 95%, and morbidity was observed in 3 patients (23%). One patient developed impaired orbital growth with mild ptosis. Another patient required orthopedic pinning of her femoral subcapital epiphysis and construction of a neobladder secondary to urethral obstruction. The third patient required reimplantation of her autotransplanted kidney secondary to chronic urinary tract infection and ureteral reflux. Conclusions: IO-HDRBT allowed for reduction in EBRT without compromising local control or disease-free survival in children with soft-tissue sarcomas. Tumor beds inaccessible to electron beam methods could be satisfactorily encompassed with IO

  5. Accelerated partial breast irradiation: An analysis of variables associated with late toxicity and long-term cosmetic outcome after high-dose-rate interstitial brachytherapy

    International Nuclear Information System (INIS)

    Wazer, David E.; Kaufman, Seth; Cuttino, Laurie; Di Petrillo, Thomas; Arthur, Douglas W.

    2006-01-01

    Purpose: To perform a detailed analysis of variables associated with late tissue effects of high-dose-rate (HDR) interstitial brachytherapy accelerated partial breast irradiation (APBI) in a large cohort of patients with prolonged follow-up. Methods and Materials: Beginning in 1995, 75 women with Stage I/II breast cancer were enrolled in identical institutional trials evaluating APBI as monotherapy after lumpectomy. Patients eligible included those with T1-2, N0-1 (≤3 nodes positive), M0 tumors of nonlobular histology with negative surgical margins, no extracapsular nodal extension, and negative results on postexcision mammogram. All patients underwent surgical excision and postoperative irradiation with HDR interstitial brachytherapy. The planning target volume was defined as the excision cavity plus a 2-cm margin. Treatment was delivered with a high-activity Ir-192 source at 3.4 Gy per fraction twice daily for 5 days to a total dose of 34 Gy. Dosimetric analyses were performed with three-dimensional postimplant dose and volume reconstructions. All patients were evaluated at 3-6-month intervals and assessed with a standardized cosmetic rating scale and according to Radiation Therapy Oncology Group late normal tissue toxicity scoring criteria. Clinical and therapy-related features were analyzed for their relationship to cosmetic outcome and toxicity rating. Clinical features analyzed included age, volume of resection, history of diabetes or hypertension, extent of axillary surgery, and systemic therapies. Therapy-related features analyzed included volume of tissue encompassed by the 100%, 150%, and 200% isodose lines (V100, V150, and V200, respectively), the dose homogeneity index (DHI), number of source dwell positions, and planar separation. Results: The median follow-up of all patients was 73 months (range, 43-118 months). The cosmetic outcome at last follow-up was rated as excellent, good, and fair/poor in 67%, 24%, and 9% of patients, respectively

  6. Long-term results of curative intraluminal high dose rate brachytherapy for endobronchial carcinoma

    Directory of Open Access Journals (Sweden)

    Kawamura Hidemasa

    2012-07-01

    Full Text Available Abstract Background The treatment strategy of central lung tumors is not established. Intraluminal brachytherapy (ILBT is widely used for palliative treatment of endobronchial tumors, however, it is also a promising option for curative treatment with limited data. This study evaluates the results after ILBT for endobronchial carcinoma. Method Sixteen-endobronchial carcinoma of 13 patients treated with ILBT in curative intent for 2000 to 2008 were retrospectively reviewed. ILBT using high dose rate 192 iridium thin wire system was performed with 5 Gy/fraction at mucosal surface. The patient age ranged from 57 to 82 years old with median 75 years old. The 16 lesions consisted of 13 central endobronchial cancers including 7 roentgenographically occult lung cancers and 3 of tracheal cancers. Of them, 10 lesions were treated with ILBT of median 20 Gy combined with external beam radiation therapy of median 45 Gy and 6 lesions were treated with ILBT alone of median 25 Gy. Results Median follow-up time was 32.5 months. Two-year survival rate and local control rate were 92.3% and 86.2%, respectively. Local recurrences were observed in 2 lesions. Three patients died due to lung cancer (1 patient and intercurrent disease (2 patients. Complications greater than grade 2 were not observed except for one grade 3 dyspnea. Conclusions ILBT combined with or without EBRT might be a curative treatment option in inoperable endobronchial carcinoma patients with tolerable complication.

  7. Clinical application of a OneDose(TM) MOSFET for skin dose measurements during internal mammary chain irradiation with high dose rate brachytherapy in carcinoma of the breast

    International Nuclear Information System (INIS)

    Kinhikar, Rajesh A; Sharma, Pramod K; Tambe, Chandrashekhar M; Mahantshetty, Umesh M; Sarin, Rajiv; Deshpande, Deepak D; Shrivastava, Shyam K

    2006-01-01

    In our earlier study, we experimentally evaluated the characteristics of a newly designed metal oxide semiconductor field effect transistor (MOSFET) OneDose(TM) in-vivo dosimetry system for Ir-192 (380 keV) energy and the results were compared with thermoluminescent dosimeters (TLDs). We have now extended the same study to the clinical application of this MOSFET as an in-vivo dosimetry system. The MOSFET was used during high dose rate brachytherapy (HDRBT) of internal mammary chain (IMC) irradiation for a carcinoma of the breast. The aim of this study was to measure the skin dose during IMC irradiation with a MOSFET and a TLD and compare it with the calculated dose with a treatment planning system (TPS). The skin dose was measured for ten patients. All the patients' treatment was planned on a PLATO treatment planning system. TLD measurements were performed to compare the accuracy of the measured results from the MOSFET. The mean doses measured with the MOSFET and the TLD were identical (0.5392 Gy, 15.85% of the prescribed dose). The mean dose was overestimated by the TPS and was 0.5923 Gy (17.42% of the prescribed dose). The TPS overestimated the skin dose by 9% as verified by the MOSFET and TLD. The MOSFET provides adequate in-vivo dosimetry for HDRBT. Immediate readout after irradiation, small size, permanent storage of dose and ease of use make the MOSFET a viable alternative for TLDs. (note)

  8. Development of computerized dose planning system and applicator for high dose rate remote afterloading irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, T. J. [Keimyung Univ., Taegu (Korea); Kim, S. W. [Fatima Hospital, Taegu (Korea); Kim, O. B.; Lee, H. J.; Won, C. H. [Keimyung Univ., Taegu (Korea); Yoon, S. M. [Dong-a Univ., Pusan (Korea)

    2000-04-01

    To design and fabricate of the high dose rate source and applicators which are tandem, ovoids and colpostat for OB/Gyn brachytherapy includes the computerized dose planning system. Designed the high dose rate Ir-192 source with nuclide atomic power irradiation and investigated the dose characteristics of fabricated brachysource. We performed the effect of self-absorption and determining the gamma constant and output factor and determined the apparent activity of designed source. he automated computer planning system provided the 2D distribution and 3D includes analysis programs. Created the high dose rate source Ir-192, 10 Ci(370GBq). The effective attenuation factor from the self-absorption and source wall was examined to 0.55 of the activity of bare source and this factor is useful for determination of the apparent activity and gamma constant 4.69 Rcm{sup 2}/mCi-hr. Fabricated the colpostat was investigated the dose distributions of frontal, axial and sagittal plane in intra-cavitary radiation therapy for cervical cancer. The reduce dose at bladder and rectum area was found about 20 % of original dose. The computerized brachytherapy planning system provides the 2-dimensional isodose and 3-D include the dose-volume histogram(DVH) with graphic-user-interface mode. emoted afterloading device was built for experiment of created Ir-192 source with film dosimetry within {+-}1 mm discrepancy. 34 refs., 25 figs., 11 tabs. (Author)

  9. Comparison of absorbed dose in the cervix carcinoma therapy by brachytherapy of high dose rate using the conventional planning and Monte Carlo simulation; Comparacao da dose absorvida no tratamento do cancer ginecologico por braquiterapia de alta taxa de dose utilizando o planejamento convencional do tratamento e simulacao de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Aneli Oliveira da

    2010-07-01

    This study aims to compare the doses received for patients submitted to brachytherapy High Dose Rate (HDR) brachytherapy, a method of treatment of the cervix carcinoma, performed in the planning system PLATO BPS with the doses obtained by Monte Carlo simulation using the radiation transport code MCNP 5 and one female anthropomorphic phantom based on voxel, the FAX. The implementation of HDR brachytherapy treatment for the cervix carcinoma consists of the insertion of an intrauterine probe and an intravaginal probe (ring or ovoid) and then two radiographs are obtained, anteroposterior (AP) and lateral (LAT) to confirm the position of the applicators in the patient and to allow the treatment planning and the determination of the absorbed dose at points of interest: rectum, bladder, sigmoid and point A, which corresponds anatomically to the crossings of the uterine arteries with ureters The absorbed doses obtained with the code MCNP 5, with the exception of the absorbed dose in the rectum and sigmoid for the simulation considering a point source of {sup 192}Ir, are lower than the absorbed doses from PLATO BPS calculations because the MCNP 5 considers the chemical compositions and densities of FAX body, not considering the medium as water. When considering the Monte Carlo simulation for a source with dimensions equal to that used in the brachytherapy irradiator used in this study, the values of calculated absorbed dose to the bladder, to the rectum, to the right point A and to the left point A were respectively lower than those determined by the treatment planning system in 33.29, 5.01, 22.93 and 19.04%. These values are almost all larger than the maximum acceptable deviation between patient planned and administered doses (5 %). With regard to the rectum and bladder, which are organs that must be protected, the present results are in favor of the radiological protection of patients. The point A, that is on the isodose of 100%, used to tumor treatment, the results

  10. 3-D conformal treatment of prostate cancer to 74 Gy vs. high-dose-rate brachytherapy boost: A cross-sectional quality-of-life survey

    International Nuclear Information System (INIS)

    Vordermark, Dirk

    2006-01-01

    The effects of two modalities of dose-escalated radiotherapy on health-related quality of life (HRQOL) were compared. Forty-one consecutive patients were treated with a 3-D conformal (3-DC) boost to 74 Gy, and 43 with high-dose rate (HDR) brachytherapy boost (2x9 Gy), following 3-D conformal treatment to 46 Gy. Median age was 70 years in both groups, median initial PSA was 7.9 μg/l in 3-DC boost patients and 8.1 μg/l in HDR boost patients. Stage was 7 in 52% and 47%, respectively. HRQOL was assessed cross-sectionally using EORTC QLQ-C30 and organ-specific PR25 modules 3-32 (median 19) and 4-25 (median 14) months after treatment, respectively. Questionnaires were completed by 93% and 97% of patients, respectively. Diarrhea and insomnia scores were significantly increased in both groups. In the PR25 module, scores of 3-DC boost and HDR boost patients for urinary, bowel and treatment-related symptoms were similar. Among responders, 34% of 3-DC boost patients and 86% of HDR boost patients had severe erectile problems. Dose escalation in prostate cancer by either 3-DC boost to 74 Gy or HDR brachytherapy boost appears to result in similar HRQOL profiles

  11. Dosimetric evaluation of a novel high dose rate (HDR) intraluminal / interstitial brachytherapy applicator for gastrointestinal and bladder cancers

    Science.gov (United States)

    Aghamiri, Seyyed Mahmoud Reza; Najarian, Siamak; Jaberi, Ramin

    2010-01-01

    High dose rate (HDR) brachytherapy is one of the accepted treatment modalities in gastro‐intestinal tract and bladder carcinomas. Considering the shortcoming of contact brachytherapy routinely used in gastrointestinal tract in treatment of big tumors or invasive method of bladder treatment, an intraluminal applicator with the capability of insertion into the tumor depth seems to be useful. This study presents some dosimetric evaluations to introduce this applicator to the clinical use. The radiation attenuation characteristics of the applicator were evaluated by means of two dosimetric methods including well‐type chamber and radiochromic film. The proposed 110 cm long applicator has a flexible structure made of stainless steel for easy passage through lumens and a needle tip to drill into big tumors. The 2 mm diameter of the applicator is thick enough for source transition, while easy passage through any narrow lumen such as endoscope or cystoscope working channel is ensured. Well‐chamber results showed an acceptably low attenuation of this steel springy applicator. Performing absolute dosimetry resulted in a correlation coefficient of R=0.9916(p‐value≈10−7) between standard interstitial applicator and the one proposed in this article. This study not only introduces a novel applicator with acceptable attenuation but also proves the response independency of the GAFCHROMIC EBT films to energy. By applying the dose response of the applicator in the treatment planning software, it can be used as a new intraluminal / interstitial applicator. PACS number: 87.53.Bn, 87.53.Jw, 29.40.Cs

  12. The relationship between milligram-hours quantity and doses at points A and B in gynecologic brachytherapy

    International Nuclear Information System (INIS)

    Martins, H.L.; Albuquerque, L.F.

    1987-01-01

    A comparison of mghr prescrition (Fletcher's system) to doses at points A and B (Manchester's system) in gynecologic brachytherapy is presented. The dose rate at points A and B from computerized isodose curves is studied. The f ratio = (dose rates)/(mgRaeq) is measured by: the ovoid charge, the curvature of uterine probe, the shifting charge of uterine probes, the lateral shifting of extern orifice in relationship of extern orifice in relationship to the pelve, the separation between the ovoids and the angulation of uterine probe. (M.A.C.) [pt

  13. Phantom's construction for dose measurement in brachytherapy

    International Nuclear Information System (INIS)

    Tri Harjanto; Hidayat Joko Puspito; Joko Triyanto

    2009-01-01

    In nuclear medicine, dose rate validation is the key for a successful process in therapy and diagnose of any deases. Therefore, the brachytherapy equipment being designed and constructed is to be validated its dose rate received by the radiated object. A phantom for such validation purpose is designed and constructed as a correct as if on site geometrical position of sources. The design of phantom consists of seven layers of flexi glass plates: 10 mm thick, 105 mm wide, and 280 mm length. All the plates are to be holed according to the size of the applicator to be used. Every surface of the flexi glass layers is grooved 1 mm wide, 1 mm depth, and 10 mm distance between the groove. The applicator inside the phantom is positioned at a certain reference for measurement. Every TLD installed has a fix position toward the reference coordinate and has an index number. By this system of phantom, the isodose system can be plotted. (author)

  14. Nationwide, Multicenter, Retrospective Study on High-Dose-Rate Brachytherapy as Monotherapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Yoshioka, Yasuo; Kotsuma, Tadayuki; Komiya, Akira; Kariya, Shinji; Konishi, Koji; Nonomura, Norio; Ogawa, Kazuhiko; Tanaka, Eiichi; Nishimura, Kensaku; Fujiuchi, Yasuyoshi; Kitamura, Hiroshi; Yamagami, Takuji; Yamasaki, Ichiro; Nishimura, Kazuo; Teshima, Teruki; Nakamura, Katsumasa; Itami, Jun

    2017-01-01

    Purpose: To present, analyze, and discuss results of a nationwide, multicenter, retrospective study on high-dose-rate brachytherapy (HDR-BT) as monotherapy for low-, intermediate-, and high-risk prostate cancer. Methods and Materials: From 1995 through 2013, 524 patients, 73 (14%) with low-risk, 207 (40%) with intermediate-risk, and 244 (47%) with high-risk prostate cancer, were treated with HDR-BT as monotherapy at 5 institutions in Japan. Dose fractionations were 27 Gy/2 fractions for 69 patients (13%), 45.5 Gy/7 fractions for 168 (32%), 49 Gy/7 fractions for 149 (28%), 54 Gy/9 fractions for 130 (25%), and others for 8 (2%). Of these patients, 156 (30%) did not receive androgen deprivation therapy, and 202 patients (39%) did receive androgen deprivation therapy 3 years. Median follow-up time was 5.9 years (range, 0.4-18.1 years), with a minimum of 2 years for surviving patients. Results: After 5 years, respective actuarial rates of no biochemical evidence of disease, overall survival, cause-specific survival, and metastasis-free survival for all patients were 92%, 97%, 99%, and 94%. For low/intermediate/high-risk patients, the 5-year no biochemical evidence of disease rates were 95%/94%/89%, the 5-year overall survival rates were 98%/98%/94%, the 5-year cause-specific survival rates were 98%/100%/98%, and the 5-year metastasis-free survival rates were 98%/95%/90%, respectively. The cumulative incidence of late grade 2 to 3 genitourinary toxicity at 5 years was 19%, and that of late grade 3 was 1%. The corresponding incidences of gastrointestinal toxicity were 3% and 0% (0.2%). No grade 4 or 5 of either type of toxicity was detected. Conclusions: The findings of this nationwide, multicenter, retrospective study demonstrate that HDR-BT as monotherapy was safe and effective for all patients with low-, intermediate-, and high-risk prostate cancer.

  15. Nationwide, Multicenter, Retrospective Study on High-Dose-Rate Brachytherapy as Monotherapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Yasuo, E-mail: yoshioka@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Kotsuma, Tadayuki [Department of Radiation Oncology, Osaka National Hospital, Osaka (Japan); Komiya, Akira [Department of Urology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama (Japan); Department of Urology, Chiba University Hospital, Chiba (Japan); Kariya, Shinji [Department of Radiology, Kochi Medical School, Kochi (Japan); Konishi, Koji [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Nonomura, Norio [Department of Urology, Osaka University Graduate School of Medicine, Osaka (Japan); Ogawa, Kazuhiko [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Tanaka, Eiichi [Department of Radiation Oncology, Osaka National Hospital, Osaka (Japan); Nishimura, Kensaku [Department of Urology, Osaka National Hospital, Osaka (Japan); Fujiuchi, Yasuyoshi; Kitamura, Hiroshi [Department of Urology, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama (Japan); Yamagami, Takuji [Department of Radiology, Kochi Medical School, Kochi (Japan); Yamasaki, Ichiro [Department of Urology, Kochi Medical School, Kochi (Japan); Nishimura, Kazuo [Department of Urology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Teshima, Teruki [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Nakamura, Katsumasa [Department of Radiation Oncology, Hamamatsu University School of Medicine, Shizuoka (Japan); Itami, Jun [Department of Radiation Oncology, National Cancer Center Hospital, Tokyo (Japan)

    2017-04-01

    Purpose: To present, analyze, and discuss results of a nationwide, multicenter, retrospective study on high-dose-rate brachytherapy (HDR-BT) as monotherapy for low-, intermediate-, and high-risk prostate cancer. Methods and Materials: From 1995 through 2013, 524 patients, 73 (14%) with low-risk, 207 (40%) with intermediate-risk, and 244 (47%) with high-risk prostate cancer, were treated with HDR-BT as monotherapy at 5 institutions in Japan. Dose fractionations were 27 Gy/2 fractions for 69 patients (13%), 45.5 Gy/7 fractions for 168 (32%), 49 Gy/7 fractions for 149 (28%), 54 Gy/9 fractions for 130 (25%), and others for 8 (2%). Of these patients, 156 (30%) did not receive androgen deprivation therapy, and 202 patients (39%) did receive androgen deprivation therapy <1 year, 112 (21%) for 1-3 years, and 54 (10%) for >3 years. Median follow-up time was 5.9 years (range, 0.4-18.1 years), with a minimum of 2 years for surviving patients. Results: After 5 years, respective actuarial rates of no biochemical evidence of disease, overall survival, cause-specific survival, and metastasis-free survival for all patients were 92%, 97%, 99%, and 94%. For low/intermediate/high-risk patients, the 5-year no biochemical evidence of disease rates were 95%/94%/89%, the 5-year overall survival rates were 98%/98%/94%, the 5-year cause-specific survival rates were 98%/100%/98%, and the 5-year metastasis-free survival rates were 98%/95%/90%, respectively. The cumulative incidence of late grade 2 to 3 genitourinary toxicity at 5 years was 19%, and that of late grade 3 was 1%. The corresponding incidences of gastrointestinal toxicity were 3% and 0% (0.2%). No grade 4 or 5 of either type of toxicity was detected. Conclusions: The findings of this nationwide, multicenter, retrospective study demonstrate that HDR-BT as monotherapy was safe and effective for all patients with low-, intermediate-, and high-risk prostate cancer.

  16. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

    International Nuclear Information System (INIS)

    Casey, Kevin E.; Kry, Stephen F.; Howell, Rebecca M.; Followill, David; Alvarez, Paola; Lawyer, Ann

    2013-01-01

    Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom.Methods: The authors designed and built an 8 × 8 × 10 cm 3 prototype phantom that had two slots capable of holding Al 2 O 3 :C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all 192 Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian 192 Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits.Results: The linearity correction factor was k L = (−9.43 × 10 −5 × dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using 60 Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian 192 Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance criterion for source strength audits under a

  17. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Kevin E.; Kry, Stephen F.; Howell, Rebecca M.; Followill, David [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 and The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, Texas 77030 (United States); Alvarez, Paola; Lawyer, Ann [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2013-11-15

    Purpose: The aim of this work was to create a mailable phantom with measurement accuracy suitable for Radiological Physics Center (RPC) audits of high dose-rate (HDR) brachytherapy sources at institutions participating in National Cancer Institute-funded cooperative clinical trials. Optically stimulated luminescence dosimeters (OSLDs) were chosen as the dosimeter to be used with the phantom.Methods: The authors designed and built an 8 × 8 × 10 cm{sup 3} prototype phantom that had two slots capable of holding Al{sub 2}O{sub 3}:C OSLDs (nanoDots; Landauer, Glenwood, IL) and a single channel capable of accepting all {sup 192}Ir HDR brachytherapy sources in current clinical use in the United States. The authors irradiated the phantom with Nucletron and Varian {sup 192}Ir HDR sources in order to determine correction factors for linearity with dose and the combined effects of irradiation energy and phantom characteristics. The phantom was then sent to eight institutions which volunteered to perform trial remote audits.Results: The linearity correction factor was k{sub L}= (−9.43 × 10{sup −5}× dose) + 1.009, where dose is in cGy, which differed from that determined by the RPC for the same batch of dosimeters using {sup 60}Co irradiation. Separate block correction factors were determined for current versions of both Nucletron and Varian {sup 192}Ir HDR sources and these vendor-specific correction factors differed by almost 2.6%. For the Nucletron source, the correction factor was 1.026 [95% confidence interval (CI) = 1.023–1.028], and for the Varian source, it was 1.000 (95% CI = 0.995–1.005). Variations in lateral source positioning up to 0.8 mm and distal/proximal source positioning up to 10 mm had minimal effect on dose measurement accuracy. The overall dose measurement uncertainty of the system was estimated to be 2.4% and 2.5% for the Nucletron and Varian sources, respectively (95% CI). This uncertainty was sufficient to establish a ±5% acceptance

  18. A fast inverse treatment planning strategy facilitating optimized catheter selection in image-guided high-dose-rate interstitial gynecologic brachytherapy.

    Science.gov (United States)

    Guthier, Christian V; Damato, Antonio L; Hesser, Juergen W; Viswanathan, Akila N; Cormack, Robert A

    2017-12-01

    Interstitial high-dose rate (HDR) brachytherapy is an important therapeutic strategy for the treatment of locally advanced gynecologic (GYN) cancers. The outcome of this therapy is determined by the quality of dose distribution achieved. This paper focuses on a novel yet simple heuristic for catheter selection for GYN HDR brachytherapy and their comparison against state of the art optimization strategies. The proposed technique is intended to act as a decision-supporting tool to select a favorable needle configuration. The presented heuristic for catheter optimization is based on a shrinkage-type algorithm (SACO). It is compared against state of the art planning in a retrospective study of 20 patients who previously received image-guided interstitial HDR brachytherapy using a Syed Neblett template. From those plans, template orientation and position are estimated via a rigid registration of the template with the actual catheter trajectories. All potential straight trajectories intersecting the contoured clinical target volume (CTV) are considered for catheter optimization. Retrospectively generated plans and clinical plans are compared with respect to dosimetric performance and optimization time. All plans were generated with one single run of the optimizer lasting 0.6-97.4 s. Compared to manual optimization, SACO yields a statistically significant (P ≤ 0.05) improved target coverage while at the same time fulfilling all dosimetric constraints for organs at risk (OARs). Comparing inverse planning strategies, dosimetric evaluation for SACO and "hybrid inverse planning and optimization" (HIPO), as gold standard, shows no statistically significant difference (P > 0.05). However, SACO provides the potential to reduce the number of used catheters without compromising plan quality. The proposed heuristic for needle selection provides fast catheter selection with optimization times suited for intraoperative treatment planning. Compared to manual optimization, the

  19. Effect of rectal enemas on rectal dosimetric parameters during high-dose-rate vaginal cuff brachytherapy. A prospective trial

    Energy Technology Data Exchange (ETDEWEB)

    Sabater, Sebastia; Andres, Ignacio; Sevillano, Marimar; Berenguer, Roberto; Aguayo, Manuel; Villas, Maria Victoria [Complejo Hospitalario Universitario de Albacete (CHUA), Department of Radiation Oncology, Albacete (Spain); Gascon, Marina; Arenas, Meritxell [Hospital Universitari Sant Joan, Department of Radiation Oncology, Reus (Spain); Rovirosa, Angeles; Camacho-Lopez, Cristina [University of Barcelona, IDIBAPS, Gynecological Cancer Unit, Radiation Oncology Department, ICMHO, Hospital Clinic, Barcelona (Spain)

    2016-04-15

    To evaluate the effects of rectal enemas on rectal doses during postoperative high-dose-rate (HDR) vaginal cuff brachytherapy (VCB). This prospective trial included 59 patients. Two rectal cleansing enemas were self-administered before the second fraction, and fraction 1 was considered the basal status. Dose-volume histogram (DVH) values were generated for the rectum and correlated with rectal volume variation. Statistical analyses used paired and unpaired t-tests. Despite a significant 15 % reduction in mean rectal volume (44.07 vs. 52.15 cc, p = 0.0018), 35.6 % of patients had larger rectums after rectal enemas. No significant rectal enema-related DVH differences were observed compared to the basal data. Although not statistically significant, rectal cleansing-associated increases in mean rectal DVH values were observed: D{sub 0.1} {sub cc}: 6.6 vs. 7.21 Gy; D{sub 1} {sub cc}: 5.35 vs. 5.52 Gy; D{sub 2} {sub cc}: 4.67 vs. 4.72 Gy, before and after rectal cleaning, respectively (where D{sub x} {sub cc} is the dose to the most exposed x cm {sup 3}). No differences were observed in DVH parameters according to rectal volume increase or decrease after the enema. Patients whose rectal volume increased also had significantly larger DVH parameters, except for D{sub 5} {sub %}, D{sub 25} {sub %}, and D{sub 50} {sub %}. In contrast, in patients whose rectal volume decreased, significance was only seen for D{sub 25} {sub %} and D{sub 50} {sub %} (D{sub x} {sub %} dose covering x % of the volume). In the latter patients, nonsignificant reductions in D{sub 2} {sub cc}, D{sub 5} {sub cc} and V{sub 5} {sub Gy} (volume receiving at least 5 Gy) were observed. The current rectal enemas protocol was ineffective in significantly modifying rectal DVH parameters for HDR-VCB. (orig.) [German] Beurteilung der Auswirkungen von rektalen Dosen waehrend postoperativer High-Dose-Rate-(HDR-)Brachytherapie an der Scheidenmanschette (''vaginal cuff brachytherapy'', VCB). An

  20. Outcomes Associated With 3 Treatment Schedules of High-Dose-Rate Brachytherapy Monotherapy for Favorable-Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jawad, Maha Saada; Dilworth, Joshua T.; Gustafson, Gary S.; Ye, Hong; Wallace, Michelle [Department of Radiation Oncology, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Martinez, Alvaro [Michigan HealthCare Professionals/21" s" t Century Oncology, Farmington Hills, Michigan (United States); Chen, Peter Y. [Department of Radiation Oncology, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States); Krauss, Daniel J., E-mail: DKrauss@beaumont.edu [Department of Radiation Oncology, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan (United States)

    2016-03-15

    Purpose: We report the outcomes associated with 3 high-dose-rate (HDR) brachytherapy regimens used as monotherapy for favorable-risk prostate cancer. Methods and Materials: Four hundred ninety-four patients with stage ≤T2b prostate cancer, Gleason score ≤7, and prostate-specific antigen levels ≤15 ng/mL underwent HDR brachytherapy as monotherapy. Of those, 319 received 38 Gy in 4 fractions, 79 received 24 Gy in 2 fractions, and 96 received 27 Gy in 2 fractions. Acute and chronic genitourinary (GU) and gastrointestinal (GI) toxicities were defined as side effects occurring ≤6 and >6 months, respectively, after radiation therapy (RT) and were graded according to the Common Terminology Criteria for Adverse Events version 3.0. The time to toxicity was calculated from the date of RT completion. Variables were analyzed with χ{sup 2} test. P values <.05 were considered significant. Results: The median overall follow-up time was 4 years (range, 5.5, 3.5, and 2.5 years for 38 Gy, 24 Gy, and 27 Gy, respectively, P<.001). Acute and chronic grade ≥2 GU and GI toxicity profiles were similar among groups. Acceptable rates of grade 2 GU toxicities were seen with overall acute/chronic frequency/urgency, dysuria, retention, incontinence, and hematuria rates of 14%/20%, 6%/7%, 7%/4%, 1.5%/2%, and 1.5%/7%, respectively. Minimal grade 3 and no grade 4 or 5 toxicities were seen. Grade 1, 2, and 3 chronic urethral stricture rates were 0.3%, 2%, and 1%, respectively. All GI toxicities were similar between groups, with overall rates of acute/chronic grade 2 diarrhea, rectal pain/tenesmus, rectal bleeding, and proctitis of 1%/1%, <1%/0.5%, 0%/2%, and <1%/1%, respectively. No grade 3, 4, or 5 toxicities were seen. All comparisons were similar for hormone-naïve patients. The median time to maximal GU/GI toxicity was similar between groups, ranging from 1 to 1.6 to 0.9 to 1.2 years, respectively. There were no differences in clinical outcomes between the 3 groups at 5

  1. Dose determination in breast tumor in brachytherapy using Iridium-192

    International Nuclear Information System (INIS)

    Okuno, S.F.

    1984-01-01

    Thermoluminescent dosimetry studies in vivo and in vitro aiming to determing radiation dose in the breast tumor, in brachytherapy using Iridium-192 was done. The correlation between radiation doses in tumor and external surface of the breast was investigated for correcting the time interval of radiation source implantation. (author) [pt

  2. External beam radiotherapy boosted with high dose rate brachytherapy in completely resected uterine sarcomas. Is this a treatment option?

    Energy Technology Data Exchange (ETDEWEB)

    Pellizzon, Antonio Cassio Assis; Novaes, Paulo Eduardo Ribeiro dos Santos; Maia, Maria Aparecida Conte; Ferrigno, Robson; Fogarolli, Ricardo; Salvajoli, Joao Vitor [Hospital de Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Oncologia de Radiacao]. E-mail: pellizzon@aol.com

    2005-04-15

    Uterine sarcoma (US) is a relative rare tumor, which accounts for only about 3-5% of all uterine cancers. Aggressive cytoreductive surgery at the time of the initial diagnosis with maximum tumor debulking may lead to a prolonged survival or cure. Objective: to identify and review the role of adjuvant external beam radiation therapy (EBRT) associated with high dose rate brachytherapy (HDRB) in the management of patients presenting US with complete resection. Material and methods: this study is a retrospective analysis of 23 patients with US treated from 10/92 to 03/03, with surgery, external beam radiation therapy (EBRT) and high dose rate brachytherapy (HDRB). The inclusion criteria for study participation included: histologically proven and graded US, completely resection of tumor, Karnofsky status 60-100, absence of significant infection, and recovery from recent surgery. Results: The median age of patients was 62 years (range 39-84); ten-year actuarial disease-free and overall survivals were 42.2% and 63.4%, respectively. On univariate analysis, predictive factors for disease-free survival (DFS) were age at initial presentation (p=0.0268), parity (p=0.0441), tumor grade (p= 0.0095), cervical or vaginal invasion (p=0.0014) and node dissection at time of surgery (p= 0.0471). On multivariate analysis, the only predictive factor was cervical or vaginal invasion (p= 0.048), hazard ratio of 4.7. Conclusion: it is quite likely that neither radiotherapy nor chemotherapy alone will appreciably improve survival in US. If radiation therapy provides better locoregional tumor control, hematogenous metastases will assume an even greater proportion of treatment failures. Unfortunately, our small and heterogeneous group analyzed precludes any definitive conclusions about the impact of HDRB associated to EBRT radiation therapy on recurrence or survival. (author)

  3. External beam radiotherapy boosted with high dose rate brachytherapy in completely resected uterine sarcomas. Is this a treatment option?

    International Nuclear Information System (INIS)

    Pellizzon, Antonio Cassio Assis; Novaes, Paulo Eduardo Ribeiro dos Santos; Maia, Maria Aparecida Conte; Ferrigno, Robson; Fogarolli, Ricardo; Salvajoli, Joao Vitor

    2005-01-01

    Uterine sarcoma (US) is a relative rare tumor, which accounts for only about 3-5% of all uterine cancers. Aggressive cytoreductive surgery at the time of the initial diagnosis with maximum tumor debulking may lead to a prolonged survival or cure. Objective: to identify and review the role of adjuvant external beam radiation therapy (EBRT) associated with high dose rate brachytherapy (HDRB) in the management of patients presenting US with complete resection. Material and methods: this study is a retrospective analysis of 23 patients with US treated from 10/92 to 03/03, with surgery, external beam radiation therapy (EBRT) and high dose rate brachytherapy (HDRB). The inclusion criteria for study participation included: histologically proven and graded US, completely resection of tumor, Karnofsky status 60-100, absence of significant infection, and recovery from recent surgery. Results: The median age of patients was 62 years (range 39-84); ten-year actuarial disease-free and overall survivals were 42.2% and 63.4%, respectively. On univariate analysis, predictive factors for disease-free survival (DFS) were age at initial presentation (p=0.0268), parity (p=0.0441), tumor grade (p= 0.0095), cervical or vaginal invasion (p=0.0014) and node dissection at time of surgery (p= 0.0471). On multivariate analysis, the only predictive factor was cervical or vaginal invasion (p= 0.048), hazard ratio of 4.7. Conclusion: it is quite likely that neither radiotherapy nor chemotherapy alone will appreciably improve survival in US. If radiation therapy provides better locoregional tumor control, hematogenous metastases will assume an even greater proportion of treatment failures. Unfortunately, our small and heterogeneous group analyzed precludes any definitive conclusions about the impact of HDRB associated to EBRT radiation therapy on recurrence or survival. (author)

  4. Brachytherapy of endometrial cancers

    International Nuclear Information System (INIS)

    Peiffert, D.; Hoffstetter, S.; Charra-Brunaud, C.

    2003-01-01

    Endometrial adenocarcinomas rank third as tumoral sites en France. The tumors are confined to the uterus in 80% of the cases. Brachytherapy has a large place in the therapeutic strategy. The gold standard treatment remains extra-fascial hysterectomy with bilateral annexiectomy and bilateral internal iliac lymph node dissection. However, after surgery alone, the rate of locoregional relapses reaches 4-20%, which is reduced to 0-5% after postoperative brachytherapy of the vaginal cuff. This postoperative brachytherapy is delivered as outpatients treatment, by 3 or 4 fractions, at high dose rate. The utero-vaginal preoperative brachytherapy remains well adapted to the tumors which involve the uterine cervix. Patients presenting a localized tumor but not operable for general reasons (< 10%) can be treated with success by exclusive irradiation, which associates a pelvic irradiation followed by an utero-vaginal brachytherapy. A high local control of about 80-90% is obtained, a little lower than surgery, with a higher risk of late complications. Last but not least, local relapses in the vaginal cuff, or in the perimeatic area, can be treated by interstitial salvage brachytherapy, associated if possible with external beam irradiation. The local control is reached in half of the patients, but metastatic dissemination is frequent. We conclude that brachytherapy has a major role in the treatment of endometrial adenocarcinomas, in combination with surgery, or with external beam irradiation for not operable patients or in case of local relapses. It should use new technologies now available including computerized after-loaders and 3D dose calculation. (authors)

  5. [Developments in brachytherapy].

    Science.gov (United States)

    Ikeda, H

    1995-09-01

    Brachytherapy is one of the ideal methods of radiotherapy because of the concentration of a high dose on the target. Recent developments, including induction of afterloading method, utilization of small-sized high-activity sources such as Iridium-192, and induction of high technology and computerization, have made for shortening of irradiation time and source handling, which has led to easier management of the patient during treatment. Dose distribution at high dose rate (HDR) is at least as good as that of low dose rate (LDR), and selection of fractionation and treatment time assures even greater biological effects on hypoxic tumor cells than LDR. Experience with HDR brachytherapy in uterine cervix cancer using Cobalt-60 during the past 20 years in this country has gradually been evaluated in U.S. and Europe. The indications for HDR treatment have extended to esophagus, bronchus, bile duct, brain, intraoperative placement of source guide, and perineal region using templates, as well as the conventional use for uterus, tongue and so on.

  6. A non-rigid point matching method with local topology preservation for accurate bladder dose summation in high dose rate cervical brachytherapy

    International Nuclear Information System (INIS)

    Chen, Haibin; Liao, Yuliang; Zhen, Xin; Zhou, Linghong; Zhong, Zichun; Pompoš, Arnold; Hrycushko, Brian; Albuquerque, Kevin; Gu, Xuejun

    2016-01-01

    GEC-ESTRO guidelines for high dose rate cervical brachytherapy advocate the reporting of the D2cc (the minimum dose received by the maximally exposed 2cc volume) to organs at risk. Due to large interfractional organ motion, reporting of accurate cumulative D2cc over a multifractional course is a non-trivial task requiring deformable image registration and deformable dose summation. To efficiently and accurately describe the point-to-point correspondence of the bladder wall over all treatment fractions while preserving local topologies, we propose a novel graphic processing unit (GPU)-based non-rigid point matching algorithm. This is achieved by introducing local anatomic information into the iterative update of correspondence matrix computation in the ‘thin plate splines-robust point matching’ (TPS-RPM) scheme. The performance of the GPU-based TPS-RPM with local topology preservation algorithm (TPS-RPM-LTP) was evaluated using four numerically simulated synthetic bladders having known deformations, a custom-made porcine bladder phantom embedded with twenty one fiducial markers, and 29 fractional computed tomography (CT) images from seven cervical cancer patients. Results show that TPS-RPM-LTP achieved excellent geometric accuracy with landmark residual distance error (RDE) of 0.7  ±  0.3 mm for the numerical synthetic data with different scales of bladder deformation and structure complexity, and 3.7  ±  1.8 mm and 1.6  ±  0.8 mm for the porcine bladder phantom with large and small deformation, respectively. The RDE accuracy of the urethral orifice landmarks in patient bladders was 3.7  ±  2.1 mm. When compared to the original TPS-RPM, the TPS-RPM-LTP improved landmark matching by reducing landmark RDE by 50  ±  19%, 37  ±  11% and 28  ±  11% for the synthetic, porcine phantom and the patient bladders, respectively. This was achieved with a computational time of less than 15 s in all cases

  7. High versus low dose-rate intracavitary irradiation for adenocarcinoma of the uterine cervix

    International Nuclear Information System (INIS)

    Kim, Woo Chul; Kim, Gwi Eon; Chung, Eun Ji; Suh, Chang Ok; Hong, Soon Won; Cho, Young Kap; Loh, John Jk

    1999-01-01

    The incidence of adenocarcinoma of the uterine cervix is low. Traditionally, Low Dose Rate (LDR) brachytherapy has been used as a standard modality in the treatment for patients with carcinoma of the uterine cervix. The purpose of this report is to evaluate the effects of the High Dose Rate (HDR) brachytherapy in the patients with adenocarcinoma of the uterine cervix compared with the LDR. From January 1971 to December 1992, 106 patients of adenocarcinoma of uterine cervix were treated with radiation therapy in the Department of Radiation Oncology, Yonsei University with curative intent. LDR brachytherapy was carried out on 35 patients and 71 patients were treated with HDR brachytherapy. In LDR Group, 8 patients were in stage I, 18 in stage II and 9 in stage III. external radiation therapy was delivered with 10 MV X-ray, daily 2 Gy fractionation, total dose 40-46 Gy (median 48 Gy). And LDR Radium intracavitary irradiation was performed with Henschke applicator, 22-56 Gy to point A (median 43 Gy). In HDR Group, there were 16 patients in stage I, 38 in stage II and 17 in stage III. The total dose of external radiation was 40-61 Gy (median 45 Gy), daily 1.8-2.0 Gy. HDR Co-60 intracavitary irradiation was performed with RALS(Remote Afterloading System), 30-57 Gy (median 39 Gy) to point A, 3 times a week, 3 Gy per fraction. The 5-year overall survival rate in LDR Group was 72.9%, 61.9%, 45.0% in stage I, II, III, respectively and corresponding figures for HDR were 87.1%, 58.3%, 41.2%, respectively (p>0.05). There was no statistical difference in terms of the 5-year overall survival rate between HDR Group and LDR Group in adenocarcinoma of the uterine cervix. There was 11% of late complication rates in LDR Group and 27% in HDR Group. There were no prognostic factors compared HDR with LDR group. The incidence of the late complication rate in HDR Group stage II, III was higher than that in LDR Group (16.7% vs. 31.6% in stage II, 11.1% vs. 35.3% in stage III, p>0

  8. 3-D conformal treatment of prostate cancer to 74 Gy vs. high-dose-rate brachytherapy boost: A cross-sectional quality-of-life survey

    Energy Technology Data Exchange (ETDEWEB)

    Vordermark, Dirk [Univ. of Wuerzburg (DE). Dept. of Radiation Oncology] (and others)

    2006-09-15

    The effects of two modalities of dose-escalated radiotherapy on health-related quality of life (HRQOL) were compared. Forty-one consecutive patients were treated with a 3-D conformal (3-DC) boost to 74 Gy, and 43 with high-dose rate (HDR) brachytherapy boost (2x9 Gy), following 3-D conformal treatment to 46 Gy. Median age was 70 years in both groups, median initial PSA was 7.9 {mu}g/l in 3-DC boost patients and 8.1 {mu}g/l in HDR boost patients. Stage was 7 in 52% and 47%, respectively. HRQOL was assessed cross-sectionally using EORTC QLQ-C30 and organ-specific PR25 modules 3-32 (median 19) and 4-25 (median 14) months after treatment, respectively. Questionnaires were completed by 93% and 97% of patients, respectively. Diarrhea and insomnia scores were significantly increased in both groups. In the PR25 module, scores of 3-DC boost and HDR boost patients for urinary, bowel and treatment-related symptoms were similar. Among responders, 34% of 3-DC boost patients and 86% of HDR boost patients had severe erectile problems. Dose escalation in prostate cancer by either 3-DC boost to 74 Gy or HDR brachytherapy boost appears to result in similar HRQOL profiles.

  9. Effect and toxicity of endoluminal high-dose-rate (HDR) brachytherapy in centrally located tumors of the upper respiratory tract

    International Nuclear Information System (INIS)

    Harms, W.; Wannenmacher, M.; Becker, H.; Herth, F.; Fritz, P.

    2000-01-01

    Aim: To assess effect an toxicity of high-dose-rate afterloading (HDR) alone or in combination with external beam radiotherapy (EBRT) in centrally located tumors of the upper respiratory tract. Patients and Methods: From 1987 to 1996, 55 patients were treated. Twenty-one patients (group A1: 17 non-small-cell lung cancer [NSCLC], A2: 4 metastases from other malignancies) were treated using HDR alone due to a relapse after external beam irradiation. In 34 previously untreated and inoperable patients (group B1: 27 NSCLC, B2: 7 metastases from other malignancies) HDR was given as a boost after EBRT (30 to 60 Gy, median 50). HDR was carried out with a 192 Ir source (370 GBq). The brachytherapy dose (group A: 5 to 27 Gy, median 20; B: 10 to 20 Gy, median 15) was prescribed to 1 cm distance from the source axis. A distanciable applicator was used in 39/55 patients. Results: In group A1, a response rate (CR, PR) of 53% (group B1: 77%) was reached. The median survival (Kaplan-Meier) was 5 months in group A1 (B1: 20 months). The 1-, 3- and 5-year local progression free survival rates (Kaplan-Meier) were 66% (15%), 52% (0%), and 37% (0%) in group B1 (group A1). Prognostic favorable factors in group B1 were a tumor diameter 70. Grade-1 or 2 toxicity (RTOG/EORTC) occurred in 0% in group A and in 6% in group B. We observed no Grad-3 or 4 toxicity. Complications caused by persistent or progressive local disease occurred in 3 patients in goup A (fatal hemorrhage, tracheomediastinal fistula, hemoptysis) and in 2 patients in group B (fatal hemorrhage, hemoptysis). Conclusions: HDR brachytherapy is an effective treatment with moderate side effects. In combination with external beam irradiation long-term remissions can be reached in one third of the patients. (orig.) [de

  10. Calculated and measured brachytherapy dosimetry parameters in water for the Xoft Axxent X-Ray Source: an electronic brachytherapy source.

    Science.gov (United States)

    Rivard, Mark J; Davis, Stephen D; DeWerd, Larry A; Rusch, Thomas W; Axelrod, Steve

    2006-11-01

    A new x-ray source, the model S700 Axxent X-Ray Source (Source), has been developed by Xoft Inc. for electronic brachytherapy. Unlike brachytherapy sources containing radionuclides, this Source may be turned on and off at will and may be operated at variable currents and voltages to change the dose rate and penetration properties. The in-water dosimetry parameters for this electronic brachytherapy source have been determined from measurements and calculations at 40, 45, and 50 kV settings. Monte Carlo simulations of radiation transport utilized the MCNP5 code and the EPDL97-based mcplib04 cross-section library. Inter-tube consistency was assessed for 20 different Sources, measured with a PTW 34013 ionization chamber. As the Source is intended to be used for a maximum of ten treatment fractions, tube stability was also assessed. Photon spectra were measured using a high-purity germanium (HPGe) detector, and calculated using MCNP. Parameters used in the two-dimensional (2D) brachytherapy dosimetry formalism were determined. While the Source was characterized as a point due to the small anode size, S700 Source exhibited depth dose behavior similar to low-energy photon-emitting low dose rate sources 125I and l03Pd, yet with capability for variable and much higher dose rates and subsequently adjustable penetration capabilities. This paper presents the calculated and measured in-water brachytherapy dosimetry parameters for the model S700 Source at the aforementioned three operating voltages.

  11. Objective method to report planner-independent skin/rib maximal dose in balloon-based high dose rate (HDR) brachytherapy for breast cancer

    International Nuclear Information System (INIS)

    Kim, Yongbok; Trombetta, Mark G.

    2011-01-01

    Purpose: An objective method was proposed and compared with a manual selection method to determine planner-independent skin and rib maximal dose in balloon-based high dose rate (HDR) brachytherapy planning. Methods: The maximal dose to skin and rib was objectively extracted from a dose volume histogram (DVH) of skin and rib volumes. A virtual skin volume was produced by expanding the skin surface in three dimensions (3D) external to the breast with a certain thickness in the planning computed tomography (CT) images. Therefore, the maximal dose to this volume occurs on the skin surface the same with a conventional manual selection method. The rib was also delineated in the planning CT images and its maximal dose was extracted from its DVH. The absolute (Abdiff=|D max Man -D max DVH |) and relative (Rediff[%]=100x(|D max Man -D max DVH |)/D max DVH ) maximal skin and rib dose differences between the manual selection method (D max Man ) and the objective method (D max DVH ) were measured for 50 balloon-based HDR (25 MammoSite and 25 Contura) patients. Results: The average±standard deviation of maximal dose difference was 1.67%±1.69% of the prescribed dose (PD). No statistical difference was observed between MammoSite and Contura patients for both Abdiff and Rediff[%] values. However, a statistically significant difference (p value max >90%) compared with lower dose range (D max <90%): 2.16%±1.93% vs 1.19%±1.25% with p value of 0.0049. However, the Rediff[%] analysis eliminated the inverse square factor and there was no statistically significant difference (p value=0.8931) between high and low dose ranges. Conclusions: The objective method using volumetric information of skin and rib can determine the planner-independent maximal dose compared with the manual selection method. However, the difference was <2% of PD, on average, if appropriate attention is paid to selecting a manual dose point in 3D planning CT images.

  12. Using the computed tomography in comparison to the orthogonal radiography based treatment planning in high dose rate (HDR) brachytherapy in cervical uteri cancer patients; a single institution feasibility study.

    Science.gov (United States)

    Bahadur, Yasir A; El-Sayed, Mohamed E; El-Taher, Zeinab H; Zaza, Khaled O; Moftah, Belal A; Hassouna, Ashraf H; Ghassal, Noor M

    2008-03-01

    Brachytherapy is an integral part in the treatment of cervical uteri cancer patients. Orthogonal treatment planning is the standard mode of calculation based on reference points. Introduction of the innovative 3-D computer based treatment planning allows accurate calculation based on volumetric information as regards the target volume and organs at risk (OAR). Also provide dose volume histogram (DVH) for proper estimation of the dose in relation to the volume. To correlate and compare the information obtained from the two approaches for high dose rate brachytherapy of cervical uteri cancer; the orthogonal conventional method and the computerized tomography (CT) three dimensions (3D) based calculation method in relation to the target and organ at risk (OAR). From 6 patients of cervical uteri cancer, 21 applications with orthogonal planning using the Brachy Vision treatment planning system version 7.3.10 were performed. In 10 applications; comparison between orthogonal and CT based planning was done. In orthogonal planning; the dose to point A, rectum and bladder were defined according to the American Brachytherapy Society (ABS) recommendation. From the CT based planning the target volume and dose volume histogram lpar;DVH) were calculated for the clinical target volume (CTV), rectum and bladder. From these two sets, information was obtained and compared and mean values were derived. For dose prescription at point A, an average of 63.5% of CTV received the prescribed dose. The mean ICRU dose to the bladder point is 2.9 Gy+/-1.2 SD (Standard Deviation) and 17% of the bladder volume derived from CT was encompassed by 2.9 Gy isodose line. The mean ICRU dose at the rectum point is 3.4 Gy+/-1.2 SD and 21% of the rectum volume from CT was encompassed by 3.4 Gy isodose line. The maximum dose to the rectum and the bladder derived from the CT and compared to the maximal dose at ICRU is 1.7 and 2.8 times higher than the orthogonal reference points; with the corresponding p

  13. Using the Computed Tomography in Comparison to the Orthogonal Radiography Based Treatment Planning in High dose Rate (HDR) Brachytherapy in Cervical Uteri Cancer Patients; A Single Institution Feasibility Study

    International Nuclear Information System (INIS)

    BAHADUR, Y.A.; EL-SAYED, M.E.; HASSOUNA, A.H.; EL-TAHER, Z.H.; GHASSAL, N.M.; ZAZA, Kh.O.M.D.; OFTAH, B.A.

    2008-01-01

    Brachytherapy is an integral part in the treatment of cervical uteri cancer patients. Orthogonal treatment planning is the standard mode of calculation based on reference points. Introduction of the innovative 3-D computer based treatment planning allows accurate calculation based on volumetric information as regards the target volume and organs at risk (OAR). Also provide dose volume histogram (DVH) for proper estimation of the dose in relation to the volume. Aim: To correlate and compare the information obtained from the two approaches for high dose rate brachytherapy of cervical uteri cancer; the orthogonal conventional method and the computerized tomography (CT) three dimensions (3D) based calculation method in relation to the target and organ at risk (OAR). Methods: From 6 patients of cervical uteri cancer, 21 applications with orthogonal planning using the Brachy Vision treatment planning system version 7.3.10 were performed. In 10 applications; comparison between orthogonal and CT based planning was done. In orthogonal planning; the dose to point A, rectum and bladder were defined according to the American Brachytherapy Society (ABS) recommendation. From the CT based planning the target volume and dose volume histogram (DVH) were calculated for the clinical target volume (CTV), rectum and bladder. From these two sets, information was obtained and compared and mean values were derived. Results: For dose prescription at point A, an average of 63.5% of CTV received the prescribed dose. The mean ICRU dose to the bladder point is 2.9 Gy±l .2 SD (Standard Deviation) and 17% of the bladder volume derived from CT was encompassed by 2.9 Gy isodose line. The mean ICRU dose at the rectum point is 3.4 Gy±1.2 SD and 21% of the rectum volume from CT was encompassed by 3.4 Gy isodose line. The maximum dose to the rectum and the bladder derived from the CT and compared to the maximal dose at ICRU is 1.7 and 2.8 times higher than the orthogonal reference points; with the

  14. SU-F-T-65: AutomaticTreatment Planning for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    International Nuclear Information System (INIS)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X

    2016-01-01

    Purpose: High dose rate (HDR) brachytherapy treatment planning is conventionally performed in a manual fashion. Yet it is highly desirable to perform computerized automated planning to improve treatment planning efficiency, eliminate human errors, and reduce plan quality variation. The goal of this research is to develop an automatic treatment planning tool for HDR brachytherapy with a cylinder applicator for vaginal cancer. Methods: After inserting the cylinder applicator into the patient, a CT scan was acquired and was loaded to an in-house developed treatment planning software. The cylinder applicator was automatically segmented using image-processing techniques. CTV was generated based on user-specified treatment depth and length. Locations of relevant points (apex point, prescription point, and vaginal surface point), central applicator channel coordinates, and dwell positions were determined according to their geometric relations with the applicator. Dwell time was computed through an inverse optimization process. The planning information was written into DICOM-RT plan and structure files to transfer the automatically generated plan to a commercial treatment planning system for plan verification and delivery. Results: We have tested the system retrospectively in nine patients treated with vaginal cylinder applicator. These cases were selected with different treatment prescriptions, lengths, depths, and cylinder diameters to represent a large patient population. Our system was able to generate treatment plans for these cases with clinically acceptable quality. Computation time varied from 3–6 min. Conclusion: We have developed a system to perform automated treatment planning for HDR brachytherapy with a cylinder applicator. Such a novel system has greatly improved treatment planning efficiency and reduced plan quality variation. It also served as a testbed to demonstrate the feasibility of automatic HDR treatment planning for more complicated cases.

  15. SU-F-T-65: AutomaticTreatment Planning for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: High dose rate (HDR) brachytherapy treatment planning is conventionally performed in a manual fashion. Yet it is highly desirable to perform computerized automated planning to improve treatment planning efficiency, eliminate human errors, and reduce plan quality variation. The goal of this research is to develop an automatic treatment planning tool for HDR brachytherapy with a cylinder applicator for vaginal cancer. Methods: After inserting the cylinder applicator into the patient, a CT scan was acquired and was loaded to an in-house developed treatment planning software. The cylinder applicator was automatically segmented using image-processing techniques. CTV was generated based on user-specified treatment depth and length. Locations of relevant points (apex point, prescription point, and vaginal surface point), central applicator channel coordinates, and dwell positions were determined according to their geometric relations with the applicator. Dwell time was computed through an inverse optimization process. The planning information was written into DICOM-RT plan and structure files to transfer the automatically generated plan to a commercial treatment planning system for plan verification and delivery. Results: We have tested the system retrospectively in nine patients treated with vaginal cylinder applicator. These cases were selected with different treatment prescriptions, lengths, depths, and cylinder diameters to represent a large patient population. Our system was able to generate treatment plans for these cases with clinically acceptable quality. Computation time varied from 3–6 min. Conclusion: We have developed a system to perform automated treatment planning for HDR brachytherapy with a cylinder applicator. Such a novel system has greatly improved treatment planning efficiency and reduced plan quality variation. It also served as a testbed to demonstrate the feasibility of automatic HDR treatment planning for more complicated cases.

  16. Positional variation of applicators during low dose rate intracavitary brachytherapy for cervical cancer: a prospective study

    Directory of Open Access Journals (Sweden)

    Arul Ponni

    2010-10-01

    Full Text Available Purpose: In order to know the effect of variation in position of applicators to the dose received by the tumor volume, critical organs such as rectum and bladder and the correlation of variation on the clinical outcome.Material and methods: 36 patients with histologically proven cervical cancer, undergoing intracavitary brachythe - rapy (ICBT from October 2005 to December 2006 were the subjects of the study. Two pairs of orthogonal X-ray films were taken: one prior to loading of sources and the other after removal of sources. These patients were followed up as per the RTOG criteria.Results: The median duration of insertion was 25 hours with a median follow up period of 6.7 months. The translational variation of the applicator position for all patients was 3 mm and 1 mm (2 SD, respectively, in the patient’s lateral and antero-posterior direction. The rotational variation was 3 and 4 degrees (2 SD in the patient’s transverse and sagittal planes. Detailed analysis of source movement showed following changes in median dose: point A: 14%, point B: 2%, point P: 1%, Rectum 1: 3.5%, Rectum 2: 4% and Bladder: 9.1%. The incidence of rectal toxicity was 6/36(16.7% and that of bladder was 1/36 (2.8%. When the variables were grouped to evaluate the relationship, our study showed statistically significant relationship between: R2 and rectal toxicity (p value: 0.002, point A and rectal toxicity (Pearson: 0.792, lateral displacement/anteroposterior displacement and rectal toxicity (p value: 0.012/0.003, beta angle and R2 (p value: 0.002.Conclusions: The geometric relationships between the ICBT applicators and the critical structures vary during the course of low dose rate brachytherapy. Source movement does result in significant dose alterations in terms of increased rate of complications, but its impact on cure rates needs to be studied in the future.

  17. Radiobiological considerations in gynaecological HDR and LDR brachytherapy

    International Nuclear Information System (INIS)

    Bauer, M.; Schulz-Wendtland, R.

    1989-01-01

    In brachytherapy the advantages of high dose rate over low dose rate afterloading therapy were obvious. Out-patient treatment becomes possible, the position of the sources is reproducible and can be observed during the treatment and the patients have to be immobilised for only a short time, giving less psychological stress and a decreased risk of thrombosis and embolism. When changing from LDR to HDR afterloading therapy we are not yet able to evaluate its biological impact. Radiobiological considerations and our experimental data, however, give us the following clinical consequences by using HDR brachytherapy: There is a need for about 15 fractions or more and each increase in dose rate requires higher fractioning. Due to the steep dose rate decline and the inhomogeneous dose distribution, multiple equivalence factors are necessary when fractioning is not sufficiently high. Correction factors to reduce the dose close to the source are low, with increasing distance from the source they increase. If HDR radiation therapy is used, the percutaneous dose in the pelvic wall region should be reduced. The reduction of the dose in HDR brachytherapy is a compromise to limit the side effects caused by the radiation. The drawback is a small therapeutic range and reduced therapeutic effectivity at the tumour. (orig.) [de

  18. American brachytherapy society recommends no change for prostate permanent implant dose prescriptions using iodine-125 or palladium-103

    International Nuclear Information System (INIS)

    Rivard, M.J.; Butler, W.M.; Merrick, G.S.; Devlin, P.M.; Hayes, J.K.; Hearn, R.A.; Lief, E.P.; Meigooni, A.S.; Williamson, J.F.

    2008-01-01

    Purpose - In 2004, the American Association of Physicists in Medicine (AAPM) issued a report outlining recommended 125 I and 103 Pd datasets for consistency in calculating brachytherapy dose distributions. In 2005, to aid evaluating the clinical impact of implementing these datasets, the AAPM assessed the historical dependence of how prescribed doses differed from administered doses for 125 I and 103 Pd for permanent implantation of the prostate. Consequently, the American Brachytherapy Society (ABS) considered the nature of these changes towards issuing recommended dose prescriptions for 125 I and 103 Pd interstitial brachytherapy implants for mono-therapy and standard boosts. Methods and materials - An investigation was performed of the 2005 AAPM analysis to determine changes in administered dose while affixing prescribed dose using 2004 AAPM 125 I and 103 Pd brachytherapy dosimetry datasets for prostate implants. For 125 I and 103 Pd, administered dose would change by +1.4% and +4.2%, respectively. The biological and societal impact of changing prescribed dose was considered. Results - Based on the need for clinical constancy and in recognition of overall uncertainties, the ABS recommends immediate implementation of the 2004 AAPM consensus brachytherapy dosimetry datasets and no changes to 125 I and 103 Pd dose prescriptions at this time. Conclusions - Radiation oncologists should continue to prescribe mono-therapy doses of 145 Gy and 125 Gy for 125 I and 105 Pd, respectively, and standard boost doses of 100-110 Gy and 90-100 Gy for 125 I and 103 Pd, respectively. (authors)

  19. High-dose-rate intracavitary brachytherapy in the management of cervical and vaginal intraepithelial neoplasia

    International Nuclear Information System (INIS)

    Ogino, Ichiro; Kitamura, Tatsuo; Okajima, Hiroyuki; Matsubara, Sho

    1998-01-01

    Purpose: To assess the effectiveness of high-dose rate intracavitary brachytherapy (HDR-ICR) in patients with grade 3 cervical intraepithelial neoplasia (CIN-3) and grade 3 vaginal intraepithelial neoplasia (VAIN-3). Methods and Materials: This was a retrospective analysis in 20 patients with CIN-3 (n = 14) or VAIN-3 (n = 6), average age 61.9 years, managed with HDR-ICR at Kanagawa Cancer Center. Two patients with CIN-3 with microinvasive foci and 11 other patients with CIN-3 were treated with HDR-ICR for cervical lesions. Six patients with CIN-3 after hysterectomy received HDR-ICR for recurrent or residual VAIN-3 lesions. One patient received radiation therapy for both CIN-3 and VAIN-3 lesions. All these patients but one were postmenopausal. Results: Seventeen patients were treated with HDR-ICR alone, and three with combined external radiation therapy. The dose was calculated at Point A located 2 cm superior to the external os and 2 cm lateral to the axis of the intrauterine tube for intact uterus. For lesions of the vaginal stump, the dose was calculated at a point 1 cm superior to the vaginal apex or 1 cm beyond vaginal mucosa. In the 14 patients treated for CIN-3 lesions, the mean total dose of HDR-ICR was 26.1 Gy (range 20-30). Six patients received HDR-ICR for VAIN-3 lesions with mean dose of 23.3 Gy (range 15-30). At follow-up (mean 90.5 months; range 13-153), 14 patients were alive and 6 had died owing to nonmalignant intercurrent disease. No patient developed recurrent disease. Rectal bleeding occurred in three patients, but this symptom subsided spontaneously. Moderate and severe vaginal reactions were noted in two patients, in whom the treatment had included the entire vagina. Conclusions: HDR-ICR can be employed as the primary management strategy for postmenopausal women with CIN-3. In intraepithelial neoplasia involving the vaginal wall after hysterectomy, HDR-ICR should be considered as an alternative to total vaginectomy

  20. dose in cervical cancer intracavitary brachytherapy

    Directory of Open Access Journals (Sweden)

    Zahra Siavashpour

    2016-04-01

    Full Text Available Purpose: To analyze the optimum organ filling point for organs at risk (OARs dose in cervical cancer high-dose-rate (HDR brachytherapy. Material and methods : In a retrospective study, 32 locally advanced cervical cancer patients (97 insertions who were treated with 3D conformal external beam radiation therapy (EBRT and concurrent chemotherapy during 2010-2013 were included. Rotterdam HDR tandem-ovoid applicators were used and computed tomography (CT scanning was performed after each insertion. The OARs delineation and GEC-ESTRO-based clinical target volumes (CTVs contouring was followed by 3D forward planning. Then, dose volume histogram (DVH parameters of organs were recorded and patients were classified based on their OARs volumes, as well as their inserted tandem length. Results : The absorbed dose to point A ranged between 6.5-7.5 Gy. D 0.1cm ³ and D 2cm ³ of the bladder significantly increased with the bladder volume enlargement (p value < 0.05. By increasing the bladder volume up to about 140 cm3, the rectum dose was also increased. For the cases with bladder volumes higher than 140 cm3, the rectum dose decreased. For bladder volumes lower than 75 cm3, the sigmoid dose decreased; however, for bladder volumes higher than 75 cm3, the sigmoid dose increased. The D 2cm ³ of the bladder and rectum were higher for longer tandems than for shorter ones, respectively. The divergence of the obtained results for different tandem lengths became wider by the extension of the bladder volume. The rectum and sigmoid volume had a direct impact on increasing their D 0.1cm ³ and D 2cm ³, as well as decreasing their D 10 , D 30 , and D 50 . Conclusions : There is a relationship between the volumes of OARs and their received doses. Selecting a bladder with a volume of about 70 cm3 or less proved to be better with regards to the dose to the bladder, rectum, and sigmoid.

  1. Cosmetic Analysis Following Breast-Conserving Surgery and Adjuvant High-Dose-Rate Interstitial Brachytherapy for Early-Stage Breast Cancer: A Prospective Clinical Study

    International Nuclear Information System (INIS)

    Garsa, Adam A.; Ferraro, Daniel J.; DeWees, Todd; Margenthaler, Julie A.; Naughton, Michael; Aft, Rebecca; Gillanders, William E.; Eberlein, Timothy; Matesa, Melissa A.; Zoberi, Imran

    2013-01-01

    Purpose: To prospectively evaluate cosmetic outcomes in women treated with accelerated partial breast irradiation using high-dose-rate interstitial brachytherapy for early-stage breast cancer. Methods and Materials: Between 2004 and 2008, 151 patients with early-stage breast cancer were enrolled in a phase 2 prospective clinical trial. Eligible patients had stage Tis-T2 tumors of ≤3 cm that were excised with negative margins and with no nodal involvement. Patients received 3.4 Gy twice daily to a total dose of 34 Gy. Both the patients and the treating radiation oncologist qualitatively rated cosmesis as excellent, good, fair, or poor over time and ascribed a cause for changes in cosmesis. Cosmetic outcome was evaluated quantitatively by percentage of breast retraction assessment (pBRA). Patients also reported their satisfaction with treatment over time. Results: Median follow-up was 55 months. The rates of excellent-to-good cosmesis reported by patients and the treating radiation oncologist were 92% and 97% pretreatment, 91% and 97% at 3 to 4 months' follow-up, 87% and 94% at 2 years, and 92% and 94% at 3 years, respectively. Breast infection and adjuvant chemotherapy were independent predictors of a fair-to-poor cosmetic outcome at 3 years. Compared to pretreatment pBRA (7.35), there was no significant change in pBRA over time. The volume receiving more than 150 Gy (V150) was the only significant predictor of pBRA. The majority of patients (86.6%) were completely satisfied with their treatment. Conclusions: Patients and the treating physician reported a high rate of excellent-to-good cosmetic outcomes at all follow-up time points. Acute breast infection and chemotherapy were associated with worse cosmetic outcomes. Multicatheter interstitial brachytherapy does not significantly change breast size as measured by pBRA

  2. Cosmetic Analysis Following Breast-Conserving Surgery and Adjuvant High-Dose-Rate Interstitial Brachytherapy for Early-Stage Breast Cancer: A Prospective Clinical Study

    Energy Technology Data Exchange (ETDEWEB)

    Garsa, Adam A.; Ferraro, Daniel J.; DeWees, Todd [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Margenthaler, Julie A. [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Naughton, Michael [Department of Medicine, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Aft, Rebecca [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Department of Surgery, John Cochran Veterans Hospital, St. Louis, Missouri (United States); Gillanders, William E.; Eberlein, Timothy [Department of Surgery, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Matesa, Melissa A. [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States); Zoberi, Imran, E-mail: izoberi@radonc.wustl.edu [Department of Radiation Oncology, Siteman Cancer Center, Barnes-Jewish Hospital and Washington University School of Medicine, St. Louis, Missouri (United States)

    2013-03-15

    Purpose: To prospectively evaluate cosmetic outcomes in women treated with accelerated partial breast irradiation using high-dose-rate interstitial brachytherapy for early-stage breast cancer. Methods and Materials: Between 2004 and 2008, 151 patients with early-stage breast cancer were enrolled in a phase 2 prospective clinical trial. Eligible patients had stage Tis-T2 tumors of ≤3 cm that were excised with negative margins and with no nodal involvement. Patients received 3.4 Gy twice daily to a total dose of 34 Gy. Both the patients and the treating radiation oncologist qualitatively rated cosmesis as excellent, good, fair, or poor over time and ascribed a cause for changes in cosmesis. Cosmetic outcome was evaluated quantitatively by percentage of breast retraction assessment (pBRA). Patients also reported their satisfaction with treatment over time. Results: Median follow-up was 55 months. The rates of excellent-to-good cosmesis reported by patients and the treating radiation oncologist were 92% and 97% pretreatment, 91% and 97% at 3 to 4 months' follow-up, 87% and 94% at 2 years, and 92% and 94% at 3 years, respectively. Breast infection and adjuvant chemotherapy were independent predictors of a fair-to-poor cosmetic outcome at 3 years. Compared to pretreatment pBRA (7.35), there was no significant change in pBRA over time. The volume receiving more than 150 Gy (V150) was the only significant predictor of pBRA. The majority of patients (86.6%) were completely satisfied with their treatment. Conclusions: Patients and the treating physician reported a high rate of excellent-to-good cosmetic outcomes at all follow-up time points. Acute breast infection and chemotherapy were associated with worse cosmetic outcomes. Multicatheter interstitial brachytherapy does not significantly change breast size as measured by pBRA.

  3. On the use of particle filters for electromagnetic tracking in high dose rate brachytherapy

    Science.gov (United States)

    Götz, Th I.; Lahmer, G.; Brandt, T.; Kallis, K.; Strnad, V.; Bert, Ch; Hensel, B.; Tomé, A. M.; Lang, E. W.

    2017-10-01

    Modern radiotherapy of female breast cancers often employs high dose rate brachytherapy, where a radioactive source is moved inside catheters, implanted in the female breast, according to a prescribed treatment plan. Source localization relative to the patient’s anatomy is determined with solenoid sensors whose spatial positions are measured with an electromagnetic tracking system. Precise sensor dwell position determination is of utmost importance to assure irradiation of the cancerous tissue according to the treatment plan. We present a hybrid data analysis system which combines multi-dimensional scaling with particle filters to precisely determine sensor dwell positions in the catheters during subsequent radiation treatment sessions. Both techniques are complemented with empirical mode decomposition for the removal of superimposed breathing artifacts. We show that the hybrid model robustly and reliably determines the spatial positions of all catheters used during the treatment and precisely determines any deviations of actual sensor dwell positions from the treatment plan. The hybrid system only relies on sensor positions measured with an EMT system and relates them to the spatial positions of the implanted catheters as initially determined with a computed x-ray tomography.

  4. SU-F-T-06: Development of a Formalism for Practical Dose Measurements in Brachytherapy in the German Standard DIN 6803

    Energy Technology Data Exchange (ETDEWEB)

    Hensley, F [Ruprecht Karl University of Heidelberg, Heidelberg (Germany); Chofor, N [Carl von Ossietzky University of Oldenburg, Oldenburg (Germany); Schoenfeld, A [University of Oldenburg, Oldenburg (Germany); Harder, D [Georg-August University of Goettingen, Goettingen (Germany)

    2016-06-15

    Purpose: In the steep dose gradients in the vicinity of a radiation source and due to the properties of the changing photon spectra, dose measurements in Brachytherapy usually have large uncertainties. Working group DIN 6803-3 is presently discussing recommendations for practical brachytherapy dosimetry incorporating recent theoretical developments in the description of brachytherapy radiation fields as well as new detectors and phantom materials. The goal is to prepare methods and instruments to verify dose calculation algorithms and for clinical dose verification with reduced uncertainties. Methods: After analysis of the distance dependent spectral changes of the radiation field surrounding brachytherapy sources, the energy dependent response of typical brachytherapy detectors was examined with Monte Carlo simulations. A dosimetric formalism was developed allowing the correction of their energy dependence as function of source distance for a Co-60 calibrated detector. Water equivalent phantom materials were examined with Monte Carlo calculations for their influence on brachytherapy photon spectra and for their water equivalence in terms of generating equivalent distributions of photon spectra and absorbed dose to water. Results: The energy dependence of a detector in the vicinity of a brachytherapy source can be described by defining an energy correction factor kQ for brachytherapy in the same manner as in existing dosimetry protocols which incorporates volume averaging and radiation field distortion by the detector. Solid phantom materials were identified which allow precise positioning of a detector together with small correctable deviations from absorbed dose to water. Recommendations for the selection of detectors and phantom materials are being developed for different measurements in brachytherapy. Conclusion: The introduction of kQ for brachytherapy sources may allow more systematic and comparable dose measurements. In principle, the corrections can be

  5. Ultrasound-guided high dose rate conformal brachytherapy boost in prostate cancer: treatment description and preliminary results of a phase I/II clinical trial

    Energy Technology Data Exchange (ETDEWEB)

    Stromberg, Jannifer; Martinez, Alvaro; Gonzalez, Jose; Edmundson, Gregory; Ohanian, Neshan; Vicini, Frank; Hollander, Jay; Gustafson, Gary; Spencer, William; Di, Yan; Brabbins, Donald

    1995-08-30

    Purpose: To improve results for locally advanced prostate cancer, a prospective clinical trial of concurrent external beam irradiation and fractionated iridium-192 (Ir-192) high dose rate (HDR) conformal boost brachytherapy was initiated. Methods and Materials: Between November 1991 and February 1994, 99 implants were performed on 33 patients with prostatic adenocarcinoma at William Beaumont Hospital. Using AJCC staging criteria, 9 patients had T2b tumors, 17 patients had T2c tumors, and 7 patients had T3 disease. Patients were treated with (a) 45.6 Gy whole pelvis external irradiation and (b) three HDR fractions of 5.5 Gy each (18 patients) or 6 Gy each (15 patients) to the prostate. Transperineal needle implants using real-time ultrasound guidance with interactive on-line isodose distributions were performed on an outpatient basis during weeks 1, 2, and 3 of external irradiation. Acute toxicity was scored using the Radiation Therapy Oncology Group (RTOG) morbidity grading system. Results: This technique of concurrent external pelvic irradiation and conformal HDR brachytherapy was well tolerated. No significant intraoperative or perioperative complications occurred. Three patients (9%) experienced Grade 3 acute toxicity (two dysuria and one diarrhea). All toxicities were otherwise Grades 1 or 2 and were primarily as expected from pelvic external irradiation. Persistent implant-related toxicities included Grades 1-2 perineal pain (12%) and hematospermia (15%). Median follow-up time was 13 months. Serum prostatic-specific antigen (PSA) levels normalized in 91% of patients (29 out of 32) within 1-14 months (median 2.8 months) after irradiation. PSA levels were progressively decreasing in the other three patients at last measurement. Prospectively planned prostatic rebiopsies done at 18 months in the first 10 patients were negative in 9 out of 10 (90%). Conclusions: Acute toxicity has been acceptable with this unique approach using conformal high dose rate Ir-192

  6. The role of brachytherapy in the definitive management of prostate cancer; Place de la curietherapie dans le traitement du cancer prostatique localise

    Energy Technology Data Exchange (ETDEWEB)

    Crook, J. [British Columbia Cancer Agency, Center for the Southern Interior, 399, Royal Avenue, Kelowna, British Columbia, V1Y 5L33 (Canada)

    2011-06-15

    Over the past two decades, brachytherapy has played an ever expanding role in the definitive radiotherapy of prostate cancer. Brachytherapy surpasses external beam radiotherapy in its ability to deliver intense intra-prostatic dose escalation. Although initially low dose rate permanent seed brachytherapy was favored for favorable risk prostate cancers, and high dose rate temporary brachytherapy for intermediate and advanced disease, both types of brachytherapy now have a place across all the risk groups of localized prostate cancer. This article will review indications and patient selection, planning and technical aspects, toxicity and efficacy for both low and high dose rate prostate brachytherapy. (author)

  7. SU-G-TeP4-05: An Evaluation of a Low Dose Rate (LDR) Prostate Brachytherapy Procedure Using a Failure Modes and Effects Analysis (FMEA)

    International Nuclear Information System (INIS)

    Cheong, S-K; Kim, J

    2016-01-01

    Purpose: The aim of the study is the application of a Failure Modes and Effects Analysis (FMEA) to access the risks for patients undergoing a Low Dose Rate (LDR) Prostate Brachytherapy Treatment. Methods: FMEA was applied to identify all the sub processes involved in the stages of identifying patient, source handling, treatment preparation, treatment delivery, and post treatment. These processes characterize the radiation treatment associated with LDR Prostate Brachytherapy. The potential failure modes together with their causes and effects were identified and ranked in order of their importance. Three indexes were assigned for each failure mode: the occurrence rating (O), the severity rating (S), and the detection rating (D). A ten-point scale was used to score each category, ten being the number indicating most severe, most frequent, and least detectable failure mode, respectively. The risk probability number (RPN) was calculated as a product of the three attributes: RPN = O X S x D. The analysis was carried out by a working group (WG) at UPMC. Results: The total of 56 failure modes were identified including 32 modes before the treatment, 13 modes during the treatment, and 11 modes after the treatment. In addition to the protocols already adopted in the clinical practice, the prioritized risk management will be implanted to the high risk procedures on the basis of RPN score. Conclusion: The effectiveness of the FMEA method was established. The FMEA methodology provides a structured and detailed assessment method for the risk analysis of the LDR Prostate Brachytherapy Procedure and can be applied to other radiation treatment modes.

  8. SU-G-TeP4-05: An Evaluation of a Low Dose Rate (LDR) Prostate Brachytherapy Procedure Using a Failure Modes and Effects Analysis (FMEA)

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, S-K; Kim, J [University of Pittsburgh Medical Center, Pittsburgh, PA (United States)

    2016-06-15

    Purpose: The aim of the study is the application of a Failure Modes and Effects Analysis (FMEA) to access the risks for patients undergoing a Low Dose Rate (LDR) Prostate Brachytherapy Treatment. Methods: FMEA was applied to identify all the sub processes involved in the stages of identifying patient, source handling, treatment preparation, treatment delivery, and post treatment. These processes characterize the radiation treatment associated with LDR Prostate Brachytherapy. The potential failure modes together with their causes and effects were identified and ranked in order of their importance. Three indexes were assigned for each failure mode: the occurrence rating (O), the severity rating (S), and the detection rating (D). A ten-point scale was used to score each category, ten being the number indicating most severe, most frequent, and least detectable failure mode, respectively. The risk probability number (RPN) was calculated as a product of the three attributes: RPN = O X S x D. The analysis was carried out by a working group (WG) at UPMC. Results: The total of 56 failure modes were identified including 32 modes before the treatment, 13 modes during the treatment, and 11 modes after the treatment. In addition to the protocols already adopted in the clinical practice, the prioritized risk management will be implanted to the high risk procedures on the basis of RPN score. Conclusion: The effectiveness of the FMEA method was established. The FMEA methodology provides a structured and detailed assessment method for the risk analysis of the LDR Prostate Brachytherapy Procedure and can be applied to other radiation treatment modes.

  9. Periodical assessment of genitourinary and gastrointestinal toxicity in patients who underwent prostate low-dose-rate brachytherapy

    International Nuclear Information System (INIS)

    Tanaka, Nobumichi; Asakawa, Isao; Anai, Satoshi; Hirayama, Akihide; Hasegawa, Masatoshi; Konishi, Noboru; Fujimoto, Kiyohide

    2013-01-01

    To compare the periodical incidence rates of genitourinary (GU) and gastrointestinal (GI) toxicity in patients who underwent prostate low-dose-rate brachytherapy between the monotherapy group (seed implantation alone) and the boost group (in combination with external beam radiation therapy (EBRT)). A total of 218 patients with a median follow-up of 42.5 months were enrolled. The patients were divided into 2 groups by treatment modality, namely, the monotherapy group (155 patients) and the boost group (63 patients). The periodical incidence rates of GU and GI toxicity were separately evaluated and compared between the monotherapy group and the boost group using the National Cancer Institute - Common Terminology Criteria for Adverse Events, version 3.0. To elucidate an independent factor among clinical and postdosimetric parameters to predict grade 2 or higher GU and GI toxicity in the acute and late phases, univariate and multivariate logistic regression analyses were carried out. Of all patients, 78.0% showed acute GU toxicity, and 7.8% showed acute GI toxicity, while 63.8% showed late GU toxicity, and 21.1% showed late GI toxicity. The incidence rates of late GU and GI toxicity were significantly higher in the boost group. Multivariate analysis showed that the International Prostate Symptom Score (IPSS) before seed implantation was a significant parameter to predict acute GU toxicity, while there were no significant predictive parameters for acute GI toxicity. On the other hand, combination with EBRT was a significant predictive parameter for late GU toxicity, and rectal volume (mL) receiving 100% of the prescribed dose (R100) was a significant predictive parameter for late GI toxicity. The boost group showed higher incidence rates of both GU and GI toxicity. Higher IPSS before seed implantation, combination with EBRT and a higher R100 were significant predictors for acute GU, late GU and late GI toxicity

  10. American Brachytherapy Society consensus report for accelerated partial breast irradiation using interstitial multicatheter brachytherapy.

    Science.gov (United States)

    Hepel, Jaroslaw T; Arthur, Douglas; Shaitelman, Simona; Polgár, Csaba; Todor, Dorin; Zoberi, Imran; Kamrava, Mitchell; Major, Tibor; Yashar, Catheryn; Wazer, David E

    To develop a consensus report for the quality practice of accelerated partial breast irradiation (APBI) using interstitial multicatheter brachytherapy (IMB). The American Brachytherapy Society Board appointed an expert panel with clinical and research experience with breast brachytherapy to provide guidance for the current practice of IMB. This report is based on a comprehensive literature review with emphasis on randomized data and expertise of the panel. Randomized trials have demonstrated equivalent efficacy of APBI using IMB compared with whole breast irradiation for select patients with early-stage breast cancer. Several techniques for placement of interstitial catheters are described, and importance of three-dimensional planning with appropriate optimization is reviewed. Optimal target definition is outlined. Commonly used dosing schemas include 50 Gy delivered in pulses of 0.6-0.8 Gy/h using pulsed-dose-rate technique and 34 Gy in 10 fractions, 32 Gy in eight fractions, or 30 Gy in seven fractions using high-dose-rate technique. Potential toxicities and strategies for toxicity avoidance are described in detail. Dosimetric constraints include limiting whole breast volume that receives ≥50% of prescription dose to 0.75 (>0.85 preferred), V 150  < 45 cc, and V 200  < 14 cc. Using an optimal implant technique coupled with optimal planning and appropriate dose constraints, a low rate of toxicity and a good-to-excellent cosmetic outcome of ≥90% is expected. IMB is an effective technique to deliver APBI for appropriately selected women with early-stage breast cancer. This consensus report has been created to assist clinicians in the appropriate practice of APBI using IMB. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  11. Treatment outcome with low-dose-rate interstitial brachytherapy in early-stage oral tongue cancers

    Directory of Open Access Journals (Sweden)

    Bhalavat Rajendra

    2009-01-01

    Full Text Available Purpose : Although radical radiotherapy is known to be equally effective for early-stage oral tongue cancers (T1-2 N0 with the added advantage of organ and function preservation, surgery remains the preferred treatment. We present outcome of patients treated with brachytherapy (BT either radical or boost. Materials and Methods : Fifty-seven patients (T1/T2 31/26 were studied. Seventeen patients (30% were treated with radical BT (50-67 Gy while 40 (70% with external beam radiation therapy (EBRT + BT (36-56 Gy + 15-38 Gy]. Low-dose-rate (LDR BT was delivered with 192 Ir wires, using plastic bead technique with varied dose rates (< 60 cGy/h in 29 patients, 60-90 cGy/h in 17, and> 90 cGy/h in 11. Results : The overall local control (LCR was achieved in 59.7% (34/57 patients. LCR for T1 and T2 was 67.8% and 50%, respectively. A total of 23 patients had failures [local: 20 (T1: 8; T2: 12 patients, node: 5 (T1:2; T2: 3, and local + nodal: 3]. Overall 5-year disease-free survival and overall survival (OAS were 51% and 67%, respectively and those for T1 and T2 was 64.5/77.4% and 38.5/54% respectively (P = 0.002. All 16 patients were salvaged. Median survival after salvage treatment was 13.5 months (6-100 months. Soft tissue necrosis was observed in 12.3% (7/57 and osteoradionecrosis in two patients. Conclusion : BT, as an integral part of radical radiation therapy in early-stage tongue cancers, appears to be an effective alternative treatment modality with preservation of the organ and function without jeopardizing the outcome.

  12. Radioablation of liver malignancies with interstitial high-dose-rate brachytherapy. Complications and risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Mohnike, Konrad; Wolf, Steffen; Damm, Robert; Seidensticker, Max; Seidensticker, Ricarda; Fischbach, Frank; Pech, Maciej; Ricke, Jens [Otto-von-Guericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany); Peters, Nils; Hass, Peter; Gademann, Guenther [Otto-von-Guericke-Universitaet, Klinik fuer Strahlentherapie, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany)

    2016-05-15

    To evaluate complications and identify risk factors for adverse events in patients undergoing high-dose-rate interstitial brachytherapy (iBT). Data from 192 patients treated in 343 CT- or MRI-guided interventions from 2006-2009 at our institution were analyzed. In 41 %, the largest tumor treated was ≥ 5 cm, 6 % of the patients had tumors ≥ 10 cm. Prior to iBT, 60 % of the patients had chemotherapy, 22 % liver resection, 19 % thermoablation or transarterial chemoembolization (TACE). Safety was the primary endpoint; survival data were obtained as the secondary endpoints. During follow-up, MRI or CT imaging was performed and clinical and laboratory parameters were obtained. The rate of major complications was below 5 %. Five major bleedings (1.5 %) occurred. The frequency of severe bleeding was significantly higher in patients with advanced liver cirrhosis. One patient developed signs of a nonclassic radiation-induced liver disease. In 3 patients, symptomatic gastrointestinal (GI) ulcers were detected. A dose exposure to the GI wall above 14 Gy/ml was a reliable threshold to predict ulcer formation. A combination of C-reactive protein ≥ 165 mg/l and/or leukocyte count ≥ 12.7 Gpt/l on the second day after the intervention predicted infection (sensitivity 90.0 %; specificity 92.8 %.) Two patients (0.6 %) died within 30 days. Median overall survival after the first liver treatment was 20.1 months for all patients and the local recurrence-free surviving proportion was 89 % after 12 months. Image-guided iBT yields a low rate of major complications and is effective. (orig.) [German] Evaluierung der Komplikationsrate und Identifizierung von Risikofaktoren fuer Komplikationen und Nebenwirkungen bei Patienten mit Lebermalignomen, die mit der hochdosierten interstitiellen Brachytherapie (iBT) behandelt wurden. Von 2006 bis 2009 wurden 192 Patienten in 343 CT- oder MRT-gefuehrten Interventionen behandelt und deren Daten ausgewertet. Der groesste behandelte Tumor war in

  13. An evaluation of a Low-Dose-Rate (LDR) brachytherapy procedure using a systems engineering & error analysis methodology for health care (SEABH) - (SAVE)

    LENUS (Irish Health Repository)

    Chadwick, Liam

    2012-03-12

    Health Care Failure Modes and Effects Analysis (HFMEA®) is an established tool for risk assessment in health care. A number of deficiencies have been identified in the method. A new method called Systems and Error Analysis Bundle for Health Care (SEABH) was developed to address these deficiencies. SEABH has been applied to a number of medical processes as part of its validation and testing. One of these, Low Dose Rate (LDR) prostate Brachytherapy is reported in this paper. The case study supported the validity of SEABH with respect to its capacity to address the weaknesses of (HFMEA®).

  14. Erectile function after prostate brachytherapy

    International Nuclear Information System (INIS)

    Merrick, Gregory S.; Butler, Wayne M.; Wallner, Kent E.; Galbreath, Robert W.; Anderson, Richard L.; Kurko, Brian S.; Lief, Jonathan H.; Allen, Zachariah A.

    2005-01-01

    Purpose: To evaluate erectile function after permanent prostate brachytherapy using a validated patient-administered questionnaire and to determine the effect of multiple clinical, treatment, and dosimetric parameters on penile erectile function. Methods and materials: A total of 226 patients with preimplant erectile function determined by the International Index of Erectile Function (IIEF) questionnaire underwent permanent prostate brachytherapy in two prospective randomized trials between February 2001 and January 2003 for clinical Stage T1c-T2c (2002 American Joint Committee on Cancer) prostate cancer. Of the 226 patients, 132 were potent before treatment and, of those, 128 (97%) completed and returned the IIEF questionnaire after brachytherapy. The median follow-up was 29.1 months. Potency was defined as an IIEF score of ≥13. The clinical, treatment, and dosimetric parameters evaluated included patient age; preimplant IIEF score; clinical T stage; pretreatment prostate-specific antigen level; Gleason score; elapsed time after implantation; preimplant nocturnal erections; body mass index; presence of hypertension or diabetes mellitus; tobacco consumption; the volume of the prostate gland receiving 100%, 150%, and 200% of the prescribed dose (V 100/150/200 ); the dose delivered to 90% of the prostate gland (D 90 ); androgen deprivation therapy; supplemental external beam radiotherapy (EBRT); isotope; prostate volume; planning volume; and radiation dose to the proximal penis. Results: The 3-year actuarial rate of potency preservation was 50.5%. For patients who maintained adequate posttreatment erectile function, the preimplant IIEF score was 29, and in patients with brachytherapy-related ED, the preimplant IIEF score was 25. The median time to the onset of ED was 5.4 months. After brachytherapy, the median IIEF score was 20 in potent patients and 3 in impotent patients. On univariate analysis, the preimplant IIEF score, patient age, presence of nocturnal

  15. Correlations of post-implant regional dosimetric parameters at 24 hours and one month, with clinical results of low-dose-rate brachytherapy for localized prostate cancer

    Directory of Open Access Journals (Sweden)

    Eiichiro Okazaki

    2017-12-01

    Full Text Available Purpose : To evaluate the correlations of post-implant regional dosimetrics at 24 hours (24 h and 1 month after implant procedures, with clinical outcomes of low-dose-rate (LDR brachytherapy for localized prostate cancer. Material and methods : Between January 2008 and December 2014, 130 consecutive patients treated for localized prostate cancer, receiving definitive iodine-125 ( 125 I brachytherapy treatment were retrospectively analyzed. All patients underwent post-implant CT imaging for dosimetric analysis at 24 h and 1 month after implantation procedure. Prostate contours were divided into quadrants: anterior-superior (ASQ, posterior-superior (PSQ, anterior-inferior (AIQ, and posterior-inferior (PIQ. Predictive factors and cut-off values of biochemical failure-free survival (BFFS and toxicities of LDR brachytherapy were analyzed. Results : The median follow-up time was 69.5 months. Seven patients (5.4% had biochemical failure. The 3-year and 5-year BFFS rates were 96.7% and 93.1%, respectively. On multivariate analysis, prostate-specific antigen and Gleason score were significant prognostic factors for biochemical failure. D 90 (the minimal dose received by 90% of the volume of PSQ and PIQ at 24 h, and D 90 of PSQ at 1 month were also significant factors. The cut-off values of PSQ D 90 were 145 Gy at 24 h and 160 Gy at 1 month. D 90 of the whole prostate was not significant at 24 h and at 1 month. D 90 of PSQ at 1 month was a significant factor for rectal hemorrhage. Conclusions : Post-implant D 90 of PSQ is significantly associated with BFFS for localized prostate cancer not only at 1 month, but also at 24 hours. D 90 of PSQ at 1 month is also a significant factor for rectal hemorrhage.

  16. Adjuvant high-dose-rate brachytherapy after external beam radiotherapy in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Oezyar, Enis; Yildz, Ferah; Akyol, Fadil H.; Atahan, I. Lale

    2002-01-01

    Purpose: To compare the local control and survival rates obtained with either external beam radiation therapy (ERT) and adjuvant high-dose-rate (HDR) brachytherapy (BRT) or ERT alone in patients with nasopharyngeal cancer. Methods and Materials: Between December 1993 and December 1999, 144 patients (106 male, 38 female) with the diagnosis of nasopharyngeal cancer were treated with either ERT and adjuvant HDR BRT (Group A) or ERT alone (Group B) at our department. BRT was not applied in 38 patients for the following reasons: (1) Unit was unavailable (n=13), (2) Patient was younger than 18 years (n=17), (3) Patient received accelerated hyperfractionated ERT (n=6), and (4) Patient refused BRT (n=2). The median age for whole group was 43 (range: 9-82 years). According to the AJCC-1997 staging system, there were 11 (7.6%), 35 (24.3%), 38 (26.4%), and 60 (41.7%) patients in Stage I, II, III, and IV, respectively. There were 57 (39.6%) patients with T1, 41 (28.5%) with T2, 20 (13.9%) with T3, and 26 (18.1%) with T4 tumors. Histopathologic diagnosis was WHO 2-3 in 137 (95.2%) patients. ERT doses ranged between 58.8 and 74 Gy (median: 66 Gy). There were significantly more patients with young age, N2 status, and Stage III disease in Group B and with Stage II disease in Group A. Significantly more patients received chemotherapy in Group B. BRT with an HDR 192 Ir microSelectron afterloading unit was delivered in 106 patients at the conclusion of ERT using a single-channel nasal applicator. Dose was prescribed at 1 cm from the source, and total dose of 12 Gy in 3 fractions on 3 consecutive days was given immediately after ERT. Besides radiotherapy, 82 (56.9%) patients received cisplatin-based chemotherapy, as well. Follow-up time ranged between 12 and 80 months (median: 32 months). Results: The two groups were comparable in terms of local recurrence, locoregional failure, regional failure, and rate of distant metastasis. Local failure was observed in 11 (10.3%) out of 106

  17. LDR vs. HDR brachytherapy for localized prostate cancer: the view from radiobiological models.

    Science.gov (United States)

    King, Christopher R

    2002-01-01

    Permanent LDR brachytherapy and temporary HDR brachytherapy are competitive techniques for clinically localized prostate radiotherapy. Although a randomized trial will likely never be conducted comparing these two forms of brachytherapy, a comparative radiobiological modeling analysis proves useful in understanding some of their intrinsic differences, several of which could be exploited to improve outcomes. Radiobiological models based upon the linear quadratic equations are presented for fractionated external beam, fractionated (192)Ir HDR brachytherapy, and (125)I and (103)Pd LDR brachytherapy. These models incorporate the dose heterogeneities present in brachytherapy based upon patient-derived dose volume histograms (DVH) as well as tumor doubling times and repair kinetics. Radiobiological parameters are normalized to correspond to three accepted clinical risk factors based upon T-stage, PSA, and Gleason score to compare models with clinical series. Tumor control probabilities (TCP) for LDR and HDR brachytherapy (as monotherapy or combined with external beam) are compared with clinical bNED survival rates. Predictions are made for dose escalation with HDR brachytherapy regimens. Model predictions for dose escalation with external beam agree with clinical data and validate the models and their underlying assumptions. Both LDR and HDR brachytherapy achieve superior tumor control when compared with external beam at conventional doses (LDR brachytherapy as boost achieves superior tumor control than when used as monotherapy. Stage for stage, both LDR and current HDR regimens achieve similar tumor control rates, in agreement with current clinical data. HDR monotherapy with large-dose fraction sizes might achieve superior tumor control compared with LDR, especially if prostate cancer possesses a high sensitivity to dose fractionation (i.e., if the alpha/beta ratio is low). Radiobiological models support the current clinical evidence for equivalent outcomes in localized

  18. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern

    Science.gov (United States)

    Borot de Battisti, M.; Maenhout, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; van Vulpen, M.; Moerland, M. A.

    2015-10-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm3to 23.3 cm3) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions.

  19. Doses determination in UCCA treatments with LDR brachytherapy using Monte Carlo methods

    International Nuclear Information System (INIS)

    Benites R, J. L.; Vega C, H. R.

    2017-10-01

    Using Monte Carlo methods, with the code MCNP5, a gynecological mannequin and a vaginal cylinder were modeled. The spatial distribution of absorbed dose rate in uterine cervical cancer (UCCA) treatments was determined under the modality of manual brachytherapy of low dose rate (B-LDR). The design of the model included the gynecological liquid water mannequin, a vaginal cylinder applicator of Lucite (PMMA) with hemisphere termination. The applicator was formed by a vaginal cylinder 10.3 cm long and 2 cm in diameter. This cylinder was mounted on a stainless steel tube 15.2 cm long by 0.6 cm in diameter. A linear array of four radioactive sources of Cesium 137 was inserted into the tube. 13 water cells of 0.5 cm in diameter were modeled around the vaginal cylinder and the absorbed dose was calculated in these. The distribution of the fluence of gamma photons in the mesh was calculated. It was found that the distribution of the absorbed dose is symmetric for cells located in the upper and lower part of the vaginal cylinder. The values of the absorbed dose rate were estimated for the date of manufacture of the sources. This result allows the use of the law of radioactive decay to determine the dose rate at any date of a gynecological treatment of B-LDR. (Author)

  20. BrachyView: proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy.

    Science.gov (United States)

    Petasecca, M; Loo, K J; Safavi-Naeini, M; Han, Z; Metcalfe, P E; Meikle, S; Pospisil, S; Jakubek, J; Bucci, J A; Zaider, M; Lerch, M L F; Qi, Y; Rosenfeld, A B

    2013-04-01

    The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5-3 mm for a 10-60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for real-time imaging (using a 3 s

  1. BrachyView: Proof-of-principle of a novel in-body gamma camera for low dose-rate prostate brachytherapy

    International Nuclear Information System (INIS)

    Petasecca, M.; Loo, K. J.; Safavi-Naeini, M.; Han, Z.; Metcalfe, P. E.; Lerch, M. L. F.; Qi, Y.; Rosenfeld, A. B.; Meikle, S.; Pospisil, S.; Jakubek, J.; Bucci, J. A.; Zaider, M.

    2013-01-01

    Purpose: The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe so as to provide anatomically correct seed positions for intraoperative planning and postimplant dosimetry. Dosimetric calculations are based on the TG-43 method using the real position of the seeds. The purpose of this paper is to demonstrate the feasibility of BrachyView using the Medipix2 pixel detector and a pinhole collimator to reconstruct the real-time 3D position of low dose-rate brachytherapy seeds in a phantom. Methods: BrachyView incorporates three Medipix2 detectors coupled to a multipinhole collimator. Three-dimensionally triangulated seed positions from multiple planar images are used to determine the seed placement in a PMMA prostate phantom in real time. MATLAB codes were used to test the reconstruction method and to optimize the device geometry. Results: The results presented in this paper show a 3D position reconstruction accuracy of the seed in the range of 0.5–3 mm for a 10–60 mm seed-to-detector distance interval (Z direction), respectively. The BrachyView system also demonstrates a spatial resolution of 0.25 mm in the XY plane for sources at 10 mm distance from Medipix2 detector plane, comparable to the theoretical value calculated for an equivalent gamma camera arrangement. The authors successfully demonstrated the capability of BrachyView for

  2. Accelerated partial breast irradiation in the elderly: 5-year results of high-dose rate multi-catheter brachytherapy

    International Nuclear Information System (INIS)

    Genebes, Caroline; Hannoun-Levi, Jean-Michel; Chand, Marie-Eve; Gal, Jocelyn; Gautier, Mathieu; Raoust, Ines; Ihrai, Tarik; Courdi, Adel; Ferrero, Jean-Marc; Peyrottes, Isabelle

    2014-01-01

    To evaluate clinical outcome after accelerated partial breast irradiation (APBI) in the elderly after high-dose-rate interstitial multi-catheter brachytherapy (HIBT). Between 2005 and 2013, 70 patients underwent APBI using HIBT. Catheter implant was performed intra or post-operatively (referred patients) after lumpectomy and axillary sentinel lymph node dissection. Once the pathological results confirmed the indication of APBI, planification CT-scan was performed to deliver 34 Gy/10f/5d or 32 Gy/8f/4d. Dose-volume adaptation was manually achieved (graphical optimization). Dosimetric results and clinical outcome were retrospectively analyzed. Physician cosmetic evaluation was reported. With a median follow-up of 60.9 months [4.6 – 90.1], median age was 80.7 years [62 – 93.1]. Regarding APBI ASTRO criteria, 61.4%, 18.6% and 20% were classified as suitable, cautionary and non-suitable respectively. Axillary sentinel lymph node dissection was performed in 94.3%; 8 pts (11.5%) presented an axillary involvement. A median dose of 34 Gy [32 – 35] in 8 to 10 fractions was delivered. Median CTV was 75.2 cc [16.9 – 210], median D90 EQD2 was 43.3 Gy [35 – 72.6] and median DHI was 0.54 [0.19 – 0.74]. One patient experienced ipsilateral recurrence (5-year local free recurrence rate: 97.6%. Five-year specific and overall survival rates were 97.9% and 93.2% respectively. Thirty-four patients (48%) presented 47 late complications classified grade 1 (80.8%) and grade 2 (19.2%) with no grade ≥ 3. Cosmetic results were considered excellent/good for 67 pts (95.7%). APBI using HIBT and respecting strict rules of implantation and planification, represents a smart alternative between no post-operative irradiation and whole breast irradiation delivered over 6 consecutive weeks

  3. Exposure dose estimation of nursing personnel and visitors following "1"2"5I brachytherapy

    International Nuclear Information System (INIS)

    Nakazato, Kazuhisa; Kikuchi, Hirosumi; Hotta, Harumi; Nishizawa, Kunihide

    2007-01-01

    An automated access management system to the controlled sickrooms for "1"2"5I brachytherapy was developed. The system consists of access control and video surveillance units. The patients implanted "1"2"5I seeds were isolated for about 20 h after surgery in the controlled sickrooms. The maximum doses and dose rates of the nurses and visitors were estimated by using the legal upper limit activity of 1,300 MBq, the measured longest staying time, and the shortest distance between the patients and individuals. Video analysis revealed activities of the nurses, patients, and visitors in the controlled sickroom, and relationships between the access frequency and staying time. The nurses' measured doses ranged from 1 to 3 μSv, and averaged 1.6 μSv. The nurses' maximum dose and dose rate were 16 μSv and 5.6 nSv·h"-"1·MBq"-"1. The visitors' maximum dose and dose rate were 6 μSv and 2.6 nSv·h"-"1·MBq"-"1. The nurses and visitors' exposure doses per patient were estimated to be negligible compared with the annual limit of the public. (author)

  4. Vaginal Dose Is Associated With Toxicity in Image Guided Tandem Ring or Ovoid-Based Brachytherapy

    International Nuclear Information System (INIS)

    Susko, Matthew; Craciunescu, Oana; Meltsner, Sheridan; Yang, Yun; Steffey, Beverly; Cai, Jing; Chino, Junzo

    2016-01-01

    Purpose: To calculate vaginal doses during image guided brachytherapy with volume-based metrics and correlate with long-term vaginal toxicity. Methods and Materials: In this institutional review board–approved study, institutional databases were searched to identify women undergoing computed tomography and/or magnetic resonance–guided brachytherapy at the Duke Cancer Center from 2009 to 2015. All insertions were contoured to include the vagina as a 3-dimensional structure. All contouring was performed on computed tomography or magnetic resonance imaging and used a 0.4-cm fixed brush to outline the applicator and/or packing, expanded to include any grossly visible vagina. The surface of the cervix was specifically excluded from the contour. High-dose-rate (HDR) and low-dose-rate (LDR) doses were converted to the equivalent dose in 2-Gy fractions using an α/β of 3 for late effects. The parameters D0.1cc, D1cc, and D2cc were calculated for all insertions and summed with prior external beam therapy. Late and subacute toxicity to the vagina were determined by the Common Terminology Criteria for Adverse Events version 4.0 and compared by the median and 4th quartile doses, via the log-rank test. Univariate and multivariate hazard ratios were calculated via Cox regression. Results: A total of 258 insertions in 62 women who underwent definitive radiation therapy including brachytherapy for cervical (n=48) and uterine cancer (n=14) were identified. Twenty HDR tandem and ovoid, 32 HDR tandem and ring, and 10 LDR tandem and ovoid insertions were contoured. The median values (interquartile ranges) for vaginal D0.1cc, D1cc, and D2cc were 157.9 (134.4-196.53) Gy, 112.6 (96.7-124.6) Gy, and 100.5 (86.8-108.4) Gy, respectively. At the 4th quartile cutoff of 108 Gy for D2cc, the rate of late grade 1 toxicity at 2 years was 61.2% (95% confidence interval [CI] 43.0%-79.4%) below 108 Gy and 83.9% (63.9%-100%) above (P=.018); grade 2 or greater toxicity was 36.2% (95% CI 15

  5. Vaginal Dose Is Associated With Toxicity in Image Guided Tandem Ring or Ovoid-Based Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Susko, Matthew; Craciunescu, Oana; Meltsner, Sheridan; Yang, Yun; Steffey, Beverly; Cai, Jing; Chino, Junzo, E-mail: junzo.chino@duke.edu

    2016-04-01

    Purpose: To calculate vaginal doses during image guided brachytherapy with volume-based metrics and correlate with long-term vaginal toxicity. Methods and Materials: In this institutional review board–approved study, institutional databases were searched to identify women undergoing computed tomography and/or magnetic resonance–guided brachytherapy at the Duke Cancer Center from 2009 to 2015. All insertions were contoured to include the vagina as a 3-dimensional structure. All contouring was performed on computed tomography or magnetic resonance imaging and used a 0.4-cm fixed brush to outline the applicator and/or packing, expanded to include any grossly visible vagina. The surface of the cervix was specifically excluded from the contour. High-dose-rate (HDR) and low-dose-rate (LDR) doses were converted to the equivalent dose in 2-Gy fractions using an α/β of 3 for late effects. The parameters D0.1cc, D1cc, and D2cc were calculated for all insertions and summed with prior external beam therapy. Late and subacute toxicity to the vagina were determined by the Common Terminology Criteria for Adverse Events version 4.0 and compared by the median and 4th quartile doses, via the log-rank test. Univariate and multivariate hazard ratios were calculated via Cox regression. Results: A total of 258 insertions in 62 women who underwent definitive radiation therapy including brachytherapy for cervical (n=48) and uterine cancer (n=14) were identified. Twenty HDR tandem and ovoid, 32 HDR tandem and ring, and 10 LDR tandem and ovoid insertions were contoured. The median values (interquartile ranges) for vaginal D0.1cc, D1cc, and D2cc were 157.9 (134.4-196.53) Gy, 112.6 (96.7-124.6) Gy, and 100.5 (86.8-108.4) Gy, respectively. At the 4th quartile cutoff of 108 Gy for D2cc, the rate of late grade 1 toxicity at 2 years was 61.2% (95% confidence interval [CI] 43.0%-79.4%) below 108 Gy and 83.9% (63.9%-100%) above (P=.018); grade 2 or greater toxicity was 36.2% (95% CI 15

  6. Vaginal Dose Is Associated With Toxicity in Image Guided Tandem Ring or Ovoid-Based Brachytherapy.

    Science.gov (United States)

    Susko, Matthew; Craciunescu, Oana; Meltsner, Sheridan; Yang, Yun; Steffey, Beverly; Cai, Jing; Chino, Junzo

    2016-04-01

    To calculate vaginal doses during image guided brachytherapy with volume-based metrics and correlate with long-term vaginal toxicity. In this institutional review board-approved study, institutional databases were searched to identify women undergoing computed tomography and/or magnetic resonance-guided brachytherapy at the Duke Cancer Center from 2009 to 2015. All insertions were contoured to include the vagina as a 3-dimensional structure. All contouring was performed on computed tomography or magnetic resonance imaging and used a 0.4-cm fixed brush to outline the applicator and/or packing, expanded to include any grossly visible vagina. The surface of the cervix was specifically excluded from the contour. High-dose-rate (HDR) and low-dose-rate (LDR) doses were converted to the equivalent dose in 2-Gy fractions using an α/β of 3 for late effects. The parameters D0.1cc, D1cc, and D2cc were calculated for all insertions and summed with prior external beam therapy. Late and subacute toxicity to the vagina were determined by the Common Terminology Criteria for Adverse Events version 4.0 and compared by the median and 4th quartile doses, via the log-rank test. Univariate and multivariate hazard ratios were calculated via Cox regression. A total of 258 insertions in 62 women who underwent definitive radiation therapy including brachytherapy for cervical (n=48) and uterine cancer (n=14) were identified. Twenty HDR tandem and ovoid, 32 HDR tandem and ring, and 10 LDR tandem and ovoid insertions were contoured. The median values (interquartile ranges) for vaginal D0.1cc, D1cc, and D2cc were 157.9 (134.4-196.53) Gy, 112.6 (96.7-124.6) Gy, and 100.5 (86.8-108.4) Gy, respectively. At the 4th quartile cutoff of 108 Gy for D2cc, the rate of late grade 1 toxicity at 2 years was 61.2% (95% confidence interval [CI] 43.0%-79.4%) below 108 Gy and 83.9% (63.9%-100%) above (P=.018); grade 2 or greater toxicity was 36.2% (95% CI 15.8%-56.6%) below 108 Gy and 70.7% (95% CI 45

  7. SU-G-201-01: An Automated Treatment Plan Quality Assurance Program for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: Plan specific quality assurance (QA) is an important step in high dose rate (HDR) brachytherapy to ensure the integrity of a treatment plan. The conventional approach is to assemble a set of plan screen-captures in a document and have an independent plan-checker to verify it. Not only is this approach cumbersome and time-consuming, using a document also limits the items that can be verified, hindering plan quality and patient safety. We have initiated efforts to develop a web-based HDR brachytherapy QA system called AutoBrachy QA, for comprehensive and efficient QA. This abstract reports a new plugin in this system for the QA of a cylinder HDR brachytherapy treatment. Methods: A cylinder plan QA module was developed using Python. It was plugged into our AutoBrachy QA system. This module extracted information from CT images and treatment plan. Image processing techniques were employed to obtain geometric parameters, e.g. cylinder diameter. A comprehensive set of eight geometrical and eight dosimetric features of the plan were validated against user specified planning parameter, such as prescription value, treatment depth and length, etc. A PDF document was generated, consisting of a summary QA sheet with all the QA results, as well as images showing plan details. Results: The cylinder QA program has been implemented in our clinic. To date, it has been used in 11 patient cases and was able to successfully perform QA tests in all of them. The QA program reduced the average plan QA time from 7 min using conventional manual approach to 0.5 min. Conclusion: Being a new module in our AutoBrachy QA system, an automated treatment plan QA module for cylinder HDR brachytherapy has been successfully developed and clinically implemented. This module improved clinical workflow and plan integrity compared to the conventional manual approach.

  8. SU-G-201-01: An Automated Treatment Plan Quality Assurance Program for High-Dose Rate (HDR) Brachytherapy with a VaginalCylinder Applicator

    International Nuclear Information System (INIS)

    Zhou, Y; Tan, J; Jiang, S; Albuquerque, K; Jia, X

    2016-01-01

    Purpose: Plan specific quality assurance (QA) is an important step in high dose rate (HDR) brachytherapy to ensure the integrity of a treatment plan. The conventional approach is to assemble a set of plan screen-captures in a document and have an independent plan-checker to verify it. Not only is this approach cumbersome and time-consuming, using a document also limits the items that can be verified, hindering plan quality and patient safety. We have initiated efforts to develop a web-based HDR brachytherapy QA system called AutoBrachy QA, for comprehensive and efficient QA. This abstract reports a new plugin in this system for the QA of a cylinder HDR brachytherapy treatment. Methods: A cylinder plan QA module was developed using Python. It was plugged into our AutoBrachy QA system. This module extracted information from CT images and treatment plan. Image processing techniques were employed to obtain geometric parameters, e.g. cylinder diameter. A comprehensive set of eight geometrical and eight dosimetric features of the plan were validated against user specified planning parameter, such as prescription value, treatment depth and length, etc. A PDF document was generated, consisting of a summary QA sheet with all the QA results, as well as images showing plan details. Results: The cylinder QA program has been implemented in our clinic. To date, it has been used in 11 patient cases and was able to successfully perform QA tests in all of them. The QA program reduced the average plan QA time from 7 min using conventional manual approach to 0.5 min. Conclusion: Being a new module in our AutoBrachy QA system, an automated treatment plan QA module for cylinder HDR brachytherapy has been successfully developed and clinically implemented. This module improved clinical workflow and plan integrity compared to the conventional manual approach.

  9. CT-image based conformal high-dose rate brachytherapy boost in the conservative treatment of stage I - II breast cancer - introducing the procedure

    International Nuclear Information System (INIS)

    Kubaszewska, M.; Skowronek, J.; Chichel, A.; Kanikowski, M.; Dymnicka, M.

    2008-01-01

    Aim: Breast-conserving surgery (BCS) followed by radiotherapy (RT) has become the standard treatment for the majority of patients with early breast cancer. With regard to boost technique some disagreements are found between groups that are emphasizing the value of electron boost treatment and groups pointing out the value of interstitial brachytherapy (BT) boost treatment. We present the preliminary results in treating selected patients with early-stage breast cancer using high-dose-rate brachytherapy (HD R-BT) as a boost after breast conservation therapy (BCT). Materials/Methods: Between January 2006 and August 2007, a total of 58 female patients with first and second stage breast cancer underwent BCT. This therapeutic procedure involves BCS, whole breast radiation therapy (WBRT) and additional irradiation to the tumour bed (boost) using interstitial HDR-BT via flexible implant tubes. A 10 Gy boost dose was received by all patients. The treatment planning was based on CT-guided 3D (three-dimensional) reconstruction of the surgical clips, implant tubes and critical structures localization (skin and ribs). The accuracy of tumour bed localization, the conformity of planning target volume and treated volume were analyzed. Results: The evaluations of implant parameters involved the use of: dose volume histogram (DVH), the volume encompassed by the 100% reference isodose surface (V100%), the high dose volumecalculation (V150%, V200%, V300%), the dose non-uniformity ratio (DNR), and the conformity index (COIN). Our results were as follows: the mean PTV volume, the mean high dose volume (V150%; V200%; V300%), the DNR and COIN mean value were estimated at 57.38, 42.98, 21.38, 7.90, 0.52 and 0.83 respectively. Conclusions: CT-guided 3D HDR-BT is most appropriate for planning the boost procedure after BT especially in large breast volume, in cases with a deep seated tumour bed, as well as in patients with high risk for local recurrences. This technique reduces the

  10. A comparison study on various low energy sources in interstitial prostate brachytherapy.

    Science.gov (United States)

    Bakhshabadi, Mahdi; Ghorbani, Mahdi; Khosroabadi, Mohsen; Knaup, Courtney; Meigooni, Ali S

    2016-02-01

    Low energy sources are routinely used in prostate brachytherapy. (125)I is one of the most commonly used sources. Low energy (131)Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of (125)I, (103)Pd, and (131)Cs sources in interstitial brachytherapy of prostate. ProstaSeed (125)I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of (103)Pd and (131)Cs were simulated with the same geometry as the ProstaSeed (125)I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, (131)Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the (103)Pd source. The higher initial absolute dose in cGy/(h.U) of (131)Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the (103)Pd source are advantages of this later brachytherapy source. Based on the total dose the (125)I source has advantage over the others due to its longer half-life.

  11. Investigation of the dose rate dependency of the PAGAT gel dosimeter at low dose rates

    International Nuclear Information System (INIS)

    Zehtabian, M.; Faghihi, R.; Zahmatkesh, M.H.; Meigooni, A.S.; Mosleh-Shirazi, M.A.; Mehdizadeh, S.; Sina, S.; Bagheri, S.

    2012-01-01

    Medical physicists need dosimeters such as gel dosimeters capable of determining three-dimensional dose distributions with high spatial resolution. To date, in combination with magnetic resonance imaging (MRI), polyacrylamide gel (PAG) polymers are the most promising gel dosimetry systems. The purpose of this work was to investigate the dose rate dependency of the PAGAT gel dosimeter at low dose rates. The gel dosimeter was used for measurement of the dose distribution around a Cs-137 source from a brachytherapy LDR source to have a range of dose rates from 0.97 Gy h −1 to 0.06 Gy h −1 . After irradiation of the PAGAT gel, it was observed that the dose measured by gel dosimetry was almost the same at different distances (different dose rates) from the source, although the points nearer the source had been expected to receive greater doses. Therefore, it was suspected that the PAGAT gel is dose rate dependent at low dose rates. To test this further, three other sets of measurements were performed by placing vials containing gel at different distances from a Cs-137 source. In the first two measurements, several plastic vials were exposed to equal doses at different dose rates. An ionization chamber was used to measure the dose rate at each distance. In addition, three TLD chips were simultaneously irradiated in order to verify the dose to each vial. In the third measurement, to test the oxygen diffusion through plastic vials, the experiment was repeated again using plastic vials in a nitrogen box and glass vials. The study indicates that oxygen diffusion through plastic vials for dose rates lower than 2 Gy h −1 would affect the gel dosimeter response and it is suggested that the plastic vials or (phantoms) in an oxygen free environment or glass vials should be used for the dosimetry of low dose rate sources using PAGAT gel to avoid oxygen diffusion through the vials.

  12. Obstructive urination problems after high-dose-rate brachytherapy boost treatment for prostate cancer are avoidable.

    Science.gov (United States)

    Kragelj, Borut

    2016-03-01

    Aiming at improving treatment individualization in patients with prostate cancer treated with combination of external beam radiotherapy and high-dose-rate brachytherapy to boost the dose to prostate (HDRB-B), the objective was to evaluate factors that have potential impact on obstructive urination problems (OUP) after HDRB-B. In the follow-up study 88 patients consecutively treated with HDRB-B at the Institute of Oncology Ljubljana in the period 2006-2011 were included. The observed outcome was deterioration of OUP (DOUP) during the follow-up period longer than 1 year. Univariate and multivariate relationship analysis between DOUP and potential risk factors (treatment factors, patients' characteristics) was carried out by using binary logistic regression. ROC curve was constructed on predicted values and the area under the curve (AUC) calculated to assess the performance of the multivariate model. Analysis was carried out on 71 patients who completed 3 years of follow-up. DOUP was noted in 13/71 (18.3%) of them. The results of multivariate analysis showed statistically significant relationship between DOUP and anti-coagulation treatment (OR 4.86, 95% C.I. limits: 1.21-19.61, p = 0.026). Also minimal dose received by 90% of the urethra volume was close to statistical significance (OR = 1.23; 95% C.I. limits: 0.98-1.07, p = 0.099). The value of AUC was 0.755. The study emphasized the relationship between DOUP and anticoagulation treatment, and suggested the multivariate model with fair predictive performance. This model potentially enables a reduction of DOUP after HDRB-B. It supports the belief that further research should be focused on urethral sphincter as a critical structure for OUP.

  13. Obstructive urination problems after high-dose-rate brachytherapy boost treatment for prostate cancer are avoidable

    International Nuclear Information System (INIS)

    Kragelj, Borut

    2016-01-01

    Aiming at improving treatment individualization in patients with prostate cancer treated with combination of external beam radiotherapy and high-dose-rate brachytherapy to boost the dose to prostate (HDRB-B), the objective was to evaluate factors that have potential impact on obstructive urination problems (OUP) after HDRB-B. In the follow-up study 88 patients consecutively treated with HDRB-B at the Institute of Oncology Ljubljana in the period 2006-2011 were included. The observed outcome was deterioration of OUP (DOUP) during the follow-up period longer than 1 year. Univariate and multivariate relationship analysis between DOUP and potential risk factors (treatment factors, patients’ characteristics) was carried out by using binary logistic regression. ROC curve was constructed on predicted values and the area under the curve (AUC) calculated to assess the performance of the multivariate model. Analysis was carried out on 71 patients who completed 3 years of follow-up. DOUP was noted in 13/71 (18.3%) of them. The results of multivariate analysis showed statistically significant relationship between DOUP and anti-coagulation treatment (OR 4.86, 95% C.I. limits: 1.21-19.61, p = 0.026). Also minimal dose received by 90% of the urethra volume was close to statistical significance (OR = 1.23; 95% C.I. limits: 0.98-1.07, p = 0.099). The value of AUC was 0.755. The study emphasized the relationship between DOUP and anticoagulation treatment, and suggested the multivariate model with fair predictive performance. This model potentially enables a reduction of DOUP after HDRB-B. It supports the belief that further research should be focused on urethral sphincter as a critical structure for OUP

  14. An analysis of acute complications and perioperative morbidity from high dose rate brachytherapy in the treatment of gynecological malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Sarkaria, Jann N; Petereit, Daniel G; Kinsella, Timothy J; Buchler, Dolores A

    1995-07-01

    Purpose: To evaluate the acute morbidity and mortality for high dose-rate (HDR) brachytherapy performed in an outpatient setting in the treatment of gynecological malignancies, and to identify possible risk factors for adverse outcomes. Materials and Methods: One hundred seventy-one patients with cervical (n=129) or uterine (n=42) carcinoma with an intact uterus were evaluated and treated from August 1989 through December 1994, with at least part of their therapy delivered with intracavitary HDR {sup 192}Ir radiation. A total of 830 ICR insertions were performed with greater than 95% done on an outpatient basis under heavy intravenous sedation using fentanyl and midazolam. Perioperative morbidity and mortality were recorded for any event occurring within 30 days of the completion of therapy. Anesthesia risk was evaluated retrospectively in all patients based on the American Society of Anesthesiologists' (ASA) Physical Class System. Results: The uterine patients, many treated with radiation alone because of morbid obesity or medical inoperability, had a significantly higher perioperative morbidity and mortality rate as compared to the cervix patient cohort. Thirteen of the 42 (31%) uterine patients and 8 of the 129 (6%) cervix patients required hospitalization within 30 days of treatment completion (p<0.001). Four of these uterine patients (10%) died of medical complications related to therapy or disease progression within 30 days, while 2 of the cervix patients (1.5%) died: one from disease progression and the other due to radiation enteritis (p=0.05). Preliminary analysis suggests that uterine patients with a high anesthesia risk score (ASA>2) experienced greater morbidity and mortality, while the best predictor of complications in the cervix patients was age greater than 70 years. For the entire cohort of patients, no correlation was found between the 30 day morbidity and mortality and the doses of fentanyl and midazolam used or the length of the procedure

  15. Evaluation of Wall Correction Factor of INER's Air-Kerma Primary Standard Chamber and Dose Variation by Source Displacement for HDR 192Ir Brachytherapy

    Directory of Open Access Journals (Sweden)

    J. H. Lee

    2013-01-01

    Full Text Available The aim of the present study was to estimate the wall effect of the self-made spherical graphite-walled cavity chamber with the Monte Carlo method for establishing the air-kerma primary standard of high-dose-rate (HDR 192Ir brachytherapy sources at the Institute of Nuclear Energy Research (INER, Taiwan. The Monte Carlo method established in this paper was also employed to respectively simulate wall correction factors of the 192Ir air-kerma standard chambers used at the National Institute of Standards and Technology (NIST, USA and the National Physical Laboratory (NPL, UK for comparisons and verification. The chamber wall correction calculation results will be incorporated into INER's HDR 192Ir primary standard in the future. For the brachytherapy treatment in the esophagus or in the bronchi, the position of the isotope may have displacement in the cavity. Thus the delivered dose would differ from the prescribed dose in the treatment plan. We also tried assessing dose distribution due to the position displacement of HDR 192Ir brachytherapy source in a phantom with a central cavity by the Monte Carlo method. The calculated results could offer a clinical reference for the brachytherapy within the human organs with cavity.

  16. SU-E-T-169: Characterization of Pacemaker/ICD Dose in SAVI HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kalavagunta, C; Lasio, G; Yi, B; Zhou, J; Lin, M [Univ. of Maryland School Of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: It is important to estimate dose to pacemaker (PM)/Implantable Cardioverter Defibrillator (ICD) before undertaking Accelerated Partial Breast Treatment using High Dose Rate (HDR) brachytherapy. Kim et al. have reported HDR PM/ICD dose using a single-source balloon applicator. To the authors knowledge, there have so far not been any published PM/ICD dosimetry literature for the Strut Adjusted Volume Implant (SAVI, Cianna Medical, Aliso Viejo, CA). This study aims to fill this gap by generating a dose look up table (LUT) to predict maximum dose to the PM/ICD in SAVI HDR brachytherapy. Methods: CT scans for 3D dosimetric planning were acquired for four SAVI applicators (6−1-mini, 6−1, 8−1 and 10−1) expanded to their maximum diameter in air. The CT datasets were imported into the Elekta Oncentra TPS for planning and each applicator was digitized in a multiplanar reconstruction window. A dose of 340 cGy was prescribed to the surface of a 1 cm expansion of the SAVI applicator cavity. Cartesian coordinates of the digitized applicator were determined in the treatment leading to the generation of a dose distribution and corresponding distance-dose prediction look up table (LUT) for distances from 2 to 15 cm (6-mini) and 2 to 20 cm (10–1).The deviation between the LUT doses and the dose to the cardiac device in a clinical case was evaluated. Results: Distance-dose look up table were compared to clinical SAVI plan and the discrepancy between the max dose predicted by the LUT and the clinical plan was found to be in the range (−0.44%, 0.74%) of the prescription dose. Conclusion: The distance-dose look up tables for SAVI applicators can be used to estimate the maximum dose to the ICD/PM, with a potential usefulness for quick assessment of dose to the cardiac device prior to applicator placement.

  17. Unresectable colorectal liver metastases. Percutaneous ablation using CT-guided high-dose-rate brachytherapy (CT-HDBRT); Nicht resektable kolorektale Lebermetastasen. Perkutane Ablation mittels CT-gesteuerter Hochdosisbrachytherapie (CT-HDBRT)

    Energy Technology Data Exchange (ETDEWEB)

    Collettini, F.; Lutter, A.; Schnapauff, D.; Denecke, T.; Gebauer, B. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of Diagnostic and Interventional Radiology; Hildebrandt, B. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of Oncology; Puhl, G. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of General, Visceral and Transplantation Surgery; Wust, P. [Charite, Campus Virchow-Klinikum, Berlin (Germany). Dept. of Radiation Oncology

    2014-06-15

    Purpose: To evaluate the clinical outcome of CT-guided high-dose-rate brachytherapy (CT-HDRBT) of unresectable colorectal liver metastases (CRLMs). Materials and Methods: Retrospective analysis of all consecutive patients with unresectable CRLMs treated with CT-HDRBT between January 2008 and November 2012. Treatment was performed by CT-guided catheter placement and high-dose-rate brachytherapy with an iridium-192 source. MRI follow-up was performed after 6 weeks and then every 3 months post-intervention. The primary endpoint was local tumor control (LTC); secondary endpoints included time to progression (TTP) and overall survival (OS). Results: 80 heavily pretreated patients with 179 metastases were available for MRI evaluation for a mean follow-up time of 16.9 months. The mean tumor diameter was 28.5 mm (range: 8 - 107 mm). No major complications were observed. A total of 23 (12.9%) local tumor progressions were observed. Lesions ≥ 4 cm in diameter showed significantly more local progression than smaller lesions (< 4 cm). 50 patients (62.5%) experienced systemic tumor progression. The median TTP was 6 months. 28 (43%) patients died during the follow-up period. The median OS after ablation was 18 months. Conclusion: CT-HDRBT is an effective technique for the treatment of unresectable CRLMs and warrants promising LTC rates compared to thermal ablative techniques. A combination with other local and systemic therapies should be evaluated in patients with lesions > 4 cm in diameter, in which higher progression rates are expected. (orig.)

  18. The feasibility study and characterization of a two-dimensional diode array in “magic phantom” for high dose rate brachytherapy quality assurance

    International Nuclear Information System (INIS)

    Espinoza, A.; Beeksma, B.; Petasecca, M.; Fuduli, I.; Porumb, C.; Cutajar, D.; Lerch, M. L. F.; Rosenfeld, A. B.; Corde, S.; Jackson, M.

    2013-01-01

    Purpose: High dose rate (HDR) brachytherapy is a radiation treatment technique capable of delivering large dose rates to the tumor. Radiation is delivered using remote afterloaders to drive highly active sources (commonly 192 Ir with an air KERMA strength range between 20 000 and 40 000 U, where 1 U = 1 μGy m 2 /h in air) through applicators directly into the patient's prescribed region of treatment. Due to the obvious ramifications of incorrect treatment while using such an active source, it is essential that there are methods for quality assurance (QA) that can directly and accurately verify the treatment plan and the functionality of the remote afterloader. This paper describes the feasibility study of a QA system for HDR brachytherapy using a phantom based two-dimensional 11 × 11 epitaxial diode array, named “magic phantom.”Methods: The HDR brachytherapy treatment plan is translated to the phantom with two rows of 10 (20 in total) HDR source flexible catheters, arranged above and below the diode array “magic plate” (MP). Four-dimensional source tracking in each catheter is based upon a developed fast iterative algorithm, utilizing the response of the diodes in close proximity to the 192 Ir source, sampled at 100 ms intervals by a fast data acquisition (DAQ) system. Using a 192 Ir source in a solid water phantom, the angular response of the developed epitaxial diodes utilized in the MP and also the variation of the MP response as a function of the source-to-detector distance (SDD) were investigated. These response data are then used by an iterative algorithm for source dwelling position determination. A measurement of the average transit speed between dwell positions was performed using the diodes and a fast DAQ.Results: The angular response of the epitaxial diode showed a variation of 15% within 360°, with two flat regions above and below the detector face with less than 5% variation. For SDD distances of between 5 and 30 mm the relative response of

  19. A phantom for verification of dwell position and time of a high dose rate brachytherapy source

    International Nuclear Information System (INIS)

    Madebo, M.; Kron, T.; Pillainayagam, J.; Franich, R.

    2012-01-01

    Accuracy of dwell position and reproducibility of dwell time are critical in high dose rate (HDR) brachytherapy. A phantom was designed to verify dwell position and dwell time reproducibility for an Ir-192 HDR stepping source using Computed Radiography (CR). The central part of the phantom, incorporating thin alternating strips of lead and acrylic, was used to measure dwell positions. The outer part of the phantom features recesses containing different absorber materials (lead, aluminium, acrylic and polystyrene foam), and was used for determining reproducibility of dwell times. Dwell position errors of <1 mm were easily detectable using the phantom. The effect of bending a transfer tube was studied with this phantom and no change of clinical significance was observed when varying the curvature of the transfer tube in typical clinical scenarios. Changes of dwell time as low as 0.1 s, the minimum dwell time of the treatment unit, could be detected by choosing dwell times over the four materials that produce identical exposure at the CR detector.

  20. Preparation and determination of kerma for Iridium 192 sources of low dose rate for brachytherapy

    International Nuclear Information System (INIS)

    Tendilla, J.I.; Tovar M, V.; Mitsoura, E.; Aguilar H, F.; Alanis M, J.

    2000-01-01

    The practice of Brachytherapy with Iridium-192 sources of low dose rate (0.4 - 0.8 Gy/h) is a technique used in the treatment of diverse illnesses. in this work the preparation, quality control and calibration are presented in terms of kerma in air of Iridium-192 using as target these recycled Iridium-Platinum wires. The targets were obtained as decayed sources of different radio therapeutical centers in the country and they were characterized by Scanning electron microscopy in order to determine their chemical composition. Subsequently it was developed an experimental design to establish the effect of neutron flux, geometrical array and irradiation time over the activity and percentage of the sources homogeneity. The homogeneity was determined by auto radiography and by Gamma spectroscopy. Once the optimal irradiation conditions were established, it is determined the apparent activity and kerma in air using a well type ionization chamber with traceability to a primary laboratory. Iridium-192 sources were obtained with an average homogeneity 96 %, apparent activity 282.129 ± 0.531 M Bq and kerma in air 0.03200 ± 0.00006 m Gy m/h A. (Author)

  1. Does inverse planning applied to Iridium192 high dose rate prostate brachytherapy improve the optimization of the dose afforded by the Paris system?

    International Nuclear Information System (INIS)

    Nickers, Philippe; Lenaerts, Eric; Thissen, Benedicte; Deneufbourg, Jean-Marie

    2005-01-01

    Background and purpose: The purpose of the work is to analyse for 192 Ir prostate brachytherapy (BT) some of the different steps in optimizing the dose delivered to the CTV, urethra and rectum. Materials and methods: Between 07/1998 and 12/2001, 166 patients were treated with 192 Ir wires providing a low dose rate, according to the Paris system philosophy and with the 2D version of the treatment planning Isis R . 40-45 Gy were delivered after an external beam radiotherapy of 40 Gy. The maximum tolerable doses for BT were 25 Gy to the anterior third of the rectum on the whole length of the implant (R dose) and 52 Gy to the urethra on a 1 cm length (U max ). A U max /CTV dose ratio >1.3 represented a pejorative value as the planned dose of 40-45 Gy could not be achieved. On the other side a ratio ≤1.25 was considered optimal and the intermediate values satisfactory. A R/CTV dose ratio 192 Ir sources. Results: At the end of a learning curve reaching a plateau after the first 71 patients, 90% of the implants with 192 Ir wires were stated at least satisfactory for a total rate of 82% for the whole population. When the 3D dosimetry for SST was used, the initial values >1.25 decreased significantly with optimization required on CTV contours and additional constraints on urethra while the R/CTV ratio was maintained under 0.55. For initial U max /CTV >1.3 or >1.25 but ≤1.3 indeed, the mean respective values of 1.41±0.16 and 1.28±0.01 decreased to 1.28±0.24 and 1.17±0.09 (P<0.001), allowing to increase the total dose to the CTV by 4 Gy. Conclusions: The Paris system which assumes a homogeneous distribution of a minimum number of catheters inside the CTV allowed to anticipate a satisfactory dosimetry in 82% of cases. However, this precision rate could be improved until 95% with an optimization approach based on an inverse planning philosophy. These new 3D optimization methods, ideally based on good quality implants at first allow to deliver the highest doses with

  2. Application of the Monte Carlo integration method in calculations of dose distributions in HDR-Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Baltas, D; Geramani, K N; Ioannidis, G T; Kolotas, C; Zamboglou, N [Strahlenklinik, Stadtische Kliniken Offenbach, Offenbach (Germany); Giannouli, S [Department of Electrical and Computer Engineering, National Technical University of Athens, Athens (Greece)

    1999-12-31

    Source anisotropy is a very important factor in brachytherapy quality assurance of high dose rate HDR Ir 192 afterloading stepping sources. If anisotropy is not taken into account then doses received by a brachytherapy patient in certain directions can be in error by a clinically significant amount. Experimental measurements of anisotropy are very labour intensive. We have shown that within acceptable limits of accuracy, Monte Carlo integration (MCI) of a modified Sievert integral (3D generalisation) can provide the necessary data within a much shorter time scale than can experiments. Hence MCI can be used for routine quality assurance schedules whenever a new design of HDR or PDR Ir 192 is used for brachytherapy afterloading. Our MCI calculation results are comparable with published experimental data and Monte Carlo simulation data for microSelectron and VariSource Ir 192 sources. We have shown not only that MCI offers advantages over alternative numerical integration methods, but also that treating filtration coefficients as radial distance-dependent functions improves Sievert integral accuracy at low energies. This paper also provides anisotropy data for three new Ir 192 sources, one for microSelectron-HDR and two for the microSelectron-PDR, for which data currently is not available. The information we have obtained in this study can be incorporated into clinical practice.

  3. Directional interstitial brachytherapy from simulation to application

    Science.gov (United States)

    Lin, Liyong

    Organs at risk (OAR) are sometimes adjacent to or embedded in or overlap with the clinical target volume (CTV) to be treated. The purpose of this PhD study is to develop directionally low energy gamma-emitting interstitial brachytherapy sources. These sources can be applied between OAR to selectively reduce hot spots in the OARs and normal tissues. The reduction of dose over undesired regions can expand patient eligibility or reduce toxicities for the treatment by conventional interstitial brachytherapy. This study covers the development of a directional source from design optimization to construction of the first prototype source. The Monte Carlo code MCNP was used to simulate the radiation transport for the designs of directional sources. We have made a special construction kit to assemble radioactive and gold-shield components precisely into D-shaped titanium containers of the first directional source. Directional sources have a similar dose distribution as conventional sources on the treated side but greatly reduced dose on the shielded side, with a sharp dose gradient between them. A three-dimensional dose deposition kernel for the 125I directional source has been calculated. Treatment plans can use both directional and conventional 125I sources at the same source strength for low-dose-rate (LDR) implants to optimize the dose distributions. For prostate tumors, directional 125I LDR brachytherapy can potentially reduce genitourinary and gastrointestinal toxicities and improve potency preservation for low risk patients. The combination of better dose distribution of directional implants and better therapeutic ratio between tumor response and late reactions enables a novel temporary LDR treatment, as opposed to permanent or high-dose-rate (HDR) brachytherapy for the intermediate risk T2b and high risk T2c tumors. Supplemental external-beam treatments can be shortened with a better brachytherapy boost for T3 tumors. In conclusion, we have successfully finished the

  4. Conventional external beam radiation therapy and high dose rate afterloading brachytherapy as a boost for patients older than 70 years

    International Nuclear Information System (INIS)

    Pellizzon, Antonio Cassio Assis; Salvajoli, Joao Vitor; Fogaroli, Ricardo Cesar; Novaes, Paulo Eduardo R.S.; Maia, Maria Aparecida Conte; Ferrigno, Robson

    2005-01-01

    The treatment options for patients with non metastatic prostate cancer range from observation, radical prostatectomy, radiation therapy, hormonal therapy to various combination of some to all of them. Objective: we evaluated the impact on biochemical control of disease (bNED), acute and late intestinal (GI) and urological (GU) morbidity for a group of patients older than 70 years presenting initial or locally advanced prostate cancer treated with fractionated high dose rate brachytherapy (HDRB) as a boost to conventional external beam radiation therapy (RT) at the Department of Radiation Oncology from Hospital do Cancer A. C. Camargo, Sao Paulo, Brazil. Methods: a total of 56 patients older than 70 were treated from March, 1997 to June, 2002. All patients had prior to HDRB a course of RT to a median dose of 45 Gy. HDRB doses ranged from 16 Gy to 20 Gy, given in 4 fractions. Results: the median age of the patients was 74.4 years (range 70-83) and the median follow-up 33 months (range 24 to 60). The 5-year actuarial bNED rate was 77%. Acute GU and GI morbidity G1-2 were seen in 17.8% and 7.1% of patients, respectively. Late G1 or G2 GU morbidity was seen in 10.7% of the patients, while late G3 morbidity was observed in 7.1% of the patients, represented by urethral strictures. Conclusion: this group of patients had similar bNED rates when compared to literature, with acceptable morbidity rates. (author)

  5. Assessment of Absorbed Dose in Persons close to the Patients during 192Ir brachytherapy for Cervical Cancer

    International Nuclear Information System (INIS)

    Jung, Joo Young; Kang, Se Sik

    2010-01-01

    According to the 2007 Annual Report of the National Cancer Registry, cervical cancer showed an occurring frequency of 7th in female cancers and 4rd in females with an age of 35-64 years. Both radiotherapy and chemotherapy are mainly used for the treatment of cervical cancer. In case of radiotherapy, brachytherapy using radioisotopes in conjunction with external-beam radiation therapy (EBRT) using a linear accelerator is used in most cases to improve the outcome of cancer treatment. Brachytherapy, one of the cervical cancer radiotherapies, is a method that can minimize the damage of normal tissues restricting absorbed dose to uterus. It is, however, necessary to conduct a quantitative assessment on brachytherapy because it may cause radiation exposure to medical care providers during the radiotherapy. Therefore, the study provides the basic research data regarding brachytherapy for cervical cancer, estimating the absorbed dose in persons close to the patients using a mathematical phantom during 192Ir brachytherapy for cervical cancer

  6. Generation of uniformly distributed dose points for anatomy-based three-dimensional dose optimization methods in brachytherapy.

    Science.gov (United States)

    Lahanas, M; Baltas, D; Giannouli, S; Milickovic, N; Zamboglou, N

    2000-05-01

    We have studied the accuracy of statistical parameters of dose distributions in brachytherapy using actual clinical implants. These include the mean, minimum and maximum dose values and the variance of the dose distribution inside the PTV (planning target volume), and on the surface of the PTV. These properties have been studied as a function of the number of uniformly distributed sampling points. These parameters, or the variants of these parameters, are used directly or indirectly in optimization procedures or for a description of the dose distribution. The accurate determination of these parameters depends on the sampling point distribution from which they have been obtained. Some optimization methods ignore catheters and critical structures surrounded by the PTV or alternatively consider as surface dose points only those on the contour lines of the PTV. D(min) and D(max) are extreme dose values which are either on the PTV surface or within the PTV. They must be avoided for specification and optimization purposes in brachytherapy. Using D(mean) and the variance of D which we have shown to be stable parameters, achieves a more reliable description of the dose distribution on the PTV surface and within the PTV volume than does D(min) and D(max). Generation of dose points on the real surface of the PTV is obligatory and the consideration of catheter volumes results in a realistic description of anatomical dose distributions.

  7. Brachytherapy source calibration, reviews, and consistency of 192Ir high-dose rate afterloading sources supplied over the period of 10 years: a retrospective analysis

    International Nuclear Information System (INIS)

    Nagappan, Balasubramanian; Kumar, Yogesh; Patel, Narayan P.; Dhull, Anil Kumar; Kaushal, Vivek

    2015-01-01

    Measurement and verification of strength of monomodal high-dose rate (mHDR) 192 Ir source supplied by the vendor is a major part of quality assurance program. Reference air kerma rate (RAKR) or air kerma strength (AKS) is the recommended quantity to specify the strength of gamma emitting brachytherapy sources. Physicist in our institution performed the source calibration as soon as each 192 Ir new source was loaded on the mHDR afterloading machine. The AKS accurately measured using a physikalisch technische werkstatten (PTW) re-entrant chamber-electrometer system in a scatter-free geometry was used to compute the air kerma rate (AKR) at one-meter distance in the air. To ensure accurate dose delivery to brachytherapy patients, measured AKS or RAKR should be entered correctly in both HDR treatment console station (TCS) as well as treatment planning system (TPS) associated with it. The clinical outcome mainly depends not only on the accuracy of the source strength measurement in the hospital but also on the correct source strength entered into both TCS and TPS software. A retrospective study on 22 mHDR V2 sources supplied by the vendor for the period of 10 years was taken up to access the accuracy of source strength supplied to the Radiotherapy department. The results are analyzed and reported. The accuracy in measured RAKR of all 22 sources supplied by vendor was well within the tolerance limits set by the national regulatory body and international recommendations. The deviations observed between measured RAKR versus manufacturer's quoted RAKR were in the range from -1.71% to +1.15%. In conclusion, the measured RAKR have good agreement with vendor quoted RAKR values. (author)

  8. Prediction of late rectal complication following high-dose-rate intracavitary brachytherapy in cancer of the uterine cervix

    International Nuclear Information System (INIS)

    Lee, Jeung Eun; Huh, Seung Jae; Park, Won; Lim, Do Hoon; Ahn, Yong Chan

    2003-01-01

    Although high-dose-rate intracavitary radiotherapy (HDR ICR) has been used in the treatment of cervical cancer, the potential for increased risk of late complication, most commonly in the rectum, is a major concern. We have previously reported on 136 patients treated with HDR brachytherapy between 1995 and 1999. The purpose of this study is to upgrade the previous data and confirm the correlation between late rectal complication and rectal dose in cervix cancer patients treated with HDR ICR. A retrospective analysis was performed for 222 patients with cervix cancer who were treated for curative intent with extemal beam radiotherapy (EBRT) and HDR ICR from July 1995 to December 2001. The median dose of EBRT was 50.4 (30.6-56.4) Gy with a daily fraction size 1.8 Gy. A total of six fractions of HDR ICR were given twice weekly with fraction size of 4 (3-5.5) Gy to A point by Iridium-192 source. The rectal dose was calculated at the rectal reference point using the barium contrast criteria in vivo measurement of the rectal dose was performed with thermoluminescent dosimeter (TLD) during HDR ICR. The median follow-up period was 39 months, ranging from 6 to 90 months. Twenty-one patients (9.5%) experienced late rectal bleeding, from 3 to 44 months (median, 13 months) after the completion of RT. The calculated rectal doses were not different between the patients with rectal bleeding and those without, but the measured rectal doses were higher in the complicated patients. The differences of the measured ICR rectal fractional dose, ICR total rectal dose, and total rectal biologically equivalent dose (BED) were statistically significant. When the measured ICR total rectal dose was beyond 16 Gy, when the ratio of the measured rectal dose to A point dose was beyond 70%, or when the measured rectal BED was over 110 GY 3 , a high possibility of late rectal complication was found. Late rectal complication was closely correlated with measured rectal dose by in vivo dosimetry using

  9. Posttraumatic Stress Disorder After High-Dose-Rate Brachytherapy for Cervical Cancer With 2 Fractions in 1 Application Under Spinal/Epidural Anesthesia: Incidence and Risk Factors

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheiner, Kathrin, E-mail: kathrin.kirchheiner@meduniwien.ac.at [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria); Czajka-Pepl, Agnieszka [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Ponocny-Seliger, Elisabeth [Department of Psychology, Sigmund Freud Private University Vienna, Vienna (Austria); Scharbert, Gisela; Wetzel, Léonore [Department of Anaesthesia, General Intensive Care and Pain Management, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Nout, Remi A. [Department of Clinical Oncology, Leiden University Medical Center, Leiden (Netherlands); Sturdza, Alina [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Dimopoulos, Johannes C. [Metropolitan Hospital, Athens (Greece); Dörr, Wolfgang; Pötter, Richard [Department of Radiation Oncology, Comprehensive Cancer Center, Medical University of Vienna/General Hospital of Vienna, Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna (Austria)

    2014-06-01

    Purpose: To investigate the psychological consequences of high-dose-rate brachytherapy with 2 fractions in 1 application under spinal/epidural anesthesia in the treatment of locally advanced cervical cancer. Methods and Materials: In 50 patients with locally advanced cervical cancer, validated questionnaires were used for prospective assessment of acute and posttraumatic stress disorder (ASD/PTSD) (Impact of Event Scale–Revision), anxiety/depression (Hospital Anxiety and Depression Scale), quality of life (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30/Cervical Cancer 24), physical functioning (World Health Organization performance status), and pain (visual analogue scale), before and during treatment and 1 week and 3 months after treatment. Qualitative interviews were recorded in open format for content analysis. Results: Symptoms of ASD occurred in 30% of patients 1 week after treatment; and of PTSD in 41% 3 months after treatment in association with this specific brachytherapy procedure. Pretreatment predictive variables explain 82% of the variance of PTSD symptoms. Helpful experiences were the support of the treatment team, psychological support, and a positive attitude. Stressful factors were pain, organizational problems during treatment, and immobility between brachytherapy fractions. Conclusions: The specific brachytherapy procedure, as performed in the investigated mono-institutional setting with 2 fractions in 1 application under spinal/epidural anesthesia, bears a considerable risk of traumatization. The source of stress seems to be not the brachytherapy application itself but the maintenance of the applicator under epidural anesthesia in the time between fractions. Patients at risk may be identified before treatment, to offer targeted psycho-social support. The patients' open reports regarding helpful experiences are an encouraging feedback for the treatment team; the reported stressful

  10. Posttraumatic Stress Disorder After High-Dose-Rate Brachytherapy for Cervical Cancer With 2 Fractions in 1 Application Under Spinal/Epidural Anesthesia: Incidence and Risk Factors

    International Nuclear Information System (INIS)

    Kirchheiner, Kathrin; Czajka-Pepl, Agnieszka; Ponocny-Seliger, Elisabeth; Scharbert, Gisela; Wetzel, Léonore; Nout, Remi A.; Sturdza, Alina; Dimopoulos, Johannes C.; Dörr, Wolfgang; Pötter, Richard

    2014-01-01

    Purpose: To investigate the psychological consequences of high-dose-rate brachytherapy with 2 fractions in 1 application under spinal/epidural anesthesia in the treatment of locally advanced cervical cancer. Methods and Materials: In 50 patients with locally advanced cervical cancer, validated questionnaires were used for prospective assessment of acute and posttraumatic stress disorder (ASD/PTSD) (Impact of Event Scale–Revision), anxiety/depression (Hospital Anxiety and Depression Scale), quality of life (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30/Cervical Cancer 24), physical functioning (World Health Organization performance status), and pain (visual analogue scale), before and during treatment and 1 week and 3 months after treatment. Qualitative interviews were recorded in open format for content analysis. Results: Symptoms of ASD occurred in 30% of patients 1 week after treatment; and of PTSD in 41% 3 months after treatment in association with this specific brachytherapy procedure. Pretreatment predictive variables explain 82% of the variance of PTSD symptoms. Helpful experiences were the support of the treatment team, psychological support, and a positive attitude. Stressful factors were pain, organizational problems during treatment, and immobility between brachytherapy fractions. Conclusions: The specific brachytherapy procedure, as performed in the investigated mono-institutional setting with 2 fractions in 1 application under spinal/epidural anesthesia, bears a considerable risk of traumatization. The source of stress seems to be not the brachytherapy application itself but the maintenance of the applicator under epidural anesthesia in the time between fractions. Patients at risk may be identified before treatment, to offer targeted psycho-social support. The patients' open reports regarding helpful experiences are an encouraging feedback for the treatment team; the reported stressful

  11. SU-F-T-16: Experimental Determination of Ionization Chamber Correction Factors for In-Phantom Measurements of Reference Air Kerma Rate and Absorbed Water Dose Rate of Brachytherapy 192Ir Source

    International Nuclear Information System (INIS)

    Chan, M; Lee, V; Wong, M; Leung, R; Law, G; Lee, K; Cheung, S; Tung, S

    2016-01-01

    Purpose: Following the method of in-phantom measurements of reference air kerma rate (Ka) at 100cm and absorbed water dose rate (Dw1) at 1cm of high-dose-rate 192Ir brachytherapy source using 60Co absorbed-dose-to-water calibrated (ND,w,60Co) ionization chamber (IC), we experimentally determined the in-phantom correction factors (kglob) of the PTW30013 (PTW, Freiburg, Germany) IC by comparing the Monte Carlo (MC)-calculated kglob of the other PTW30016 IC. Methods: The Dw1 formalism of in-phantom measurement is: M*ND,w,60Co*(kglob)Dw1, where M is the collected charges, and (kglob)Dw1 the in-phantom Dw1 correction factor. Similarly, Ka is determined by M*ND,w,60Co*(kglob)ka, where (kglob)ka the in-phantom Ka correction factor. Two thimble ICs PTW30013 and another PTW30016 having a ND,w,60Co from the German primary standard laboratory (PTB) were simultaneously exposed to the microselectron 192Ir v2 source at 8cm in a PMMA phantom. A reference well chamber (PTW33004) with a PTB transfer Ka calibration Nka was used for comparing the in-phantom measurements to derive the experimental (kglob)ka factors. We determined the experimental (kglob)Dw1 of the PTW30013 by comparing the PTW30016 measurements with MC-calculated (kglob)Dw1. Results: Ka results of the PTW30016 based on ND,w,60Co and MC-calculated (kglob)ka differ from the well chamber results based on Nka by 1.6% and from the manufacturer by 1.0%. Experimental (kglob)ka factors for the PTW30016 and two other PTW30013 are 0.00683, 0.00681 and 0.00679, and vary <0.5% with 1mm source positioning uncertainty. Experimental (kglob)Dw1 of the PTW30013 ICs are 75.3 and 75.6, and differ by 1.6% from the conversion by dose rate constant from the AAPM report 229. Conclusion: The 1.7% difference between MC and experimental (kglob)ka for the PTW30016 IC is within the PTB 2.5% expanded uncertainty in Ka calibration standard. Using a single IC with ND,w,60Co to calibrate the brachytherapy source and dose output in external

  12. Late toxicity and five year outcomes after high-dose-rate brachytherapy as a monotherapy for localized prostate cancer

    International Nuclear Information System (INIS)

    Ghadjar, Pirus; Oesch, Sebastian L; Rentsch, Cyrill A; Isaak, Bernhard; Cihoric, Nikola; Manser, Peter; Thalmann, George N; Aebersold, Daniel M

    2014-01-01

    To determine the 5-year outcome after high-dose-rate brachytherapy (HDR-BT) as a monotherapy. Between 10/2003 and 06/2006, 36 patients with low (28) and intermediate (8) risk prostate cancer were treated by HDR-BT monotherapy. All patients received one implant and 4 fractions of 9.5 Gy within 48 hours for a total prescribed dose (PD) of 38 Gy. Five patients received concomitant androgen deprivation therapy (ADT). Toxicity was scored according to the common terminology criteria for adverse events from the National Cancer Institute (CTCAE) version 3.0. Biochemical recurrence was defined according to the Phoenix criteria and analyzed using the Kaplan Meier method. Predictors for late grade 3 GU toxicity were analyzed using univariate and multivariate Cox regression analyses. The median follow-up was 6.9 years (range, 1.5-8.0 years). Late grade 2 and 3 genitourinary (GU) toxicity was observed in 10 (28%) and 7 (19%) patients, respectively. The actuarial proportion of patients with late grade 3 GU toxicity at 5 years was 17.7%. Late grade 2 and 3 gastrointestinal (GI) toxicities were not observed. The crude erectile function preservation rate in patients without ADT was 75%. The 5 year biochemical recurrence-free survival (bRFS) rate was 97%. Late grade 3 GU toxicity was associated with the urethral volume (p = 0.001) and the urethral V 120 (urethral volume receiving ≥120% of the PD; p = 0.0005) after multivariate Cox regression. After HDR-BT monotherapy late grade 3 GU was observed relatively frequently and was associated with the urethral V 120 . GI toxicity was negligible, the erectile function preservation rate and the bRFS rate was excellent

  13. Accelerated partial-breast irradiation using high-dose-rate interstitial brachytherapy: 12-year update of a prospective clinical study

    International Nuclear Information System (INIS)

    Polgar, Csaba; Major, Tibor; Fodor, Janos; Sulyok, Zoltan; Somogyi, Andras; Loevey, Katalin; Nemeth, Gyoergy; Kasler, Miklos

    2010-01-01

    Background and purpose: To report the 12-year updated results of accelerated partial-breast irradiation (APBI) using multicatheter interstitial high-dose-rate (HDR) brachytherapy (BT). Patients and methods: Forty-five prospectively selected patients with T1N0-N1mi, nonlobular breast cancer without the presence of an extensive intraductal component and with negative surgical margins were treated with APBI after breast-conserving surgery (BCS) using interstitial HDR BT. A total dose of 30.3 Gy (n = 8) and 36.4 Gy (n = 37) in seven fractions within 4 days was delivered to the tumour bed plus a 1-2 cm margin. The median follow-up time was 133 months for surviving patients. Local and regional control, disease-free (DFS), cancer-specific (CSS), and overall survival (OS), as well as late side effects, and cosmetic results were assessed. Results: Four (8.9%) ipsilateral breast tumour recurrences were observed, for a 5-, 10-, and 12-year actuarial rate of 4.4%, 9.3%, and 9.3%, respectively. A total of two regional nodal failures were observed for a 12-year actuarial rate of 4.4%. The 12-year DFS, CSS, and OS was 75.3%, 91.1%, and 88.9%, respectively. Grade 3 fibrosis was observed in one patient (2.2%). No patient developed grade 3 teleangiectasia. Fat necrosis requiring surgical intervention occurred in one woman (2.2%). Cosmetic results were rated excellent or good in 35 patients (77.8%). Conclusions: Twelve-year results with APBI using HDR multicatheter interstitial implants continue to demonstrate excellent long-term local tumour control, survival, and cosmetic results with a low-rate of late side effects.

  14. A comparison study on various low energy sources in interstitial prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Mahdi Bakhshabadi

    2016-02-01

    Full Text Available Purpose: Low energy sources are routinely used in prostate brachytherapy. 125 I is one of the most commonly used sources. Low energy 131 Cs source was introduced recently as a brachytherapy source. The aim of this study is to compare dose distributions of 125 I, 103 Pd, and 131 Cs sources in interstitial brachytherapy of prostate. Material and methods: ProstaSeed 125 I brachytherapy source was simulated using MCNPX Monte Carlo code. Additionally, two hypothetical sources of 103 Pd and 131 Cs were simulated with the same geometry as the ProstaSeed 125 I source, while having their specific emitted gamma spectra. These brachytherapy sources were simulated with distribution of forty-eight seeds in a phantom including prostate. The prostate was considered as a sphere with radius of 1.5 cm. Absolute and relative dose rates were obtained in various distances from the source along the transverse and longitudinal axes inside and outside the tumor. Furthermore, isodose curves were plotted around the sources. Results : Analyzing the initial dose profiles for various sources indicated that with the same time duration and air kerma strength, 131 Cs delivers higher dose to tumor. However, relative dose rate inside the tumor is higher and outside the tumor is lower for the 103 Pd source. Conclusions : The higher initial absolute dose in cGy/(h.U of 131 Cs brachytherapy source is an advantage of this source over the others. The higher relative dose inside the tumor and lower relative dose outside the tumor for the 103 Pd source are advantages of this later brachytherapy source. Based on the total dose the 125 I source has advantage over the others due to its longer half-life.

  15. Radiotherapy alone in the treatment of uterine cervix cancer with telecobalt and low-dose-rate brachytherapy: retrospective analysis of results and variables

    International Nuclear Information System (INIS)

    Ferrigno, Robson; Campos de Oliveira Faria, Sergio Luis; Weltman, Eduardo; Salvajoli, Joao Victor; Segreto, Roberto Araujo; Pastore, Ayrton; Nadalin, Wladimir

    2003-01-01

    Purpose: This retrospective analysis aims to report results and variables from patients with cervix cancer treated by radiation therapy alone with telecobalt and low-dose-rate brachytherapy (LDRB). Methods and Materials: Between September 1989 and September 1995, 190 patients with histologic diagnosis of cervix carcinoma were treated with telecobalt for external beam radiotherapy (EBR), followed by one or two insertions of LDRB. Stage distribution according to patients was the following: IB, 12; IIA, 4; IIB, 105; and IIIB, 69. Median dose of EBR at whole pelvis was 40 Gy, and median parametrial doses for Stages II and III patients were 50 Gy and 60 Gy, respectively. Median doses of LDRB at point A for patients treated with one and two insertions were 38 Gy and 50 Gy, respectively. Results: Median follow-up time was 70 months (range: 8-127 months). Overall survival, disease-free survival, and 5-year local control of patients at Stages I, II, and III were 83%, 78%, and 46%; 83%, 82%, and 49%; and 92%, 87%, and 58%, respectively. Overall incidence of late complications in the rectum, small bowel, and urinary tract was 15.3% (19/190), 4.2% (8/190), and 6.8% (13/190), respectively. The actuarial 5-year rectal, small bowel, and urinary incidence of late complications was 16.1%, 4.6%, and 7.6%, respectively. Clinical stage was the only significant variable for overall 5-year survival (p = 0.001), for disease-free survival (p=0.001), and for local control (p=0.001). Stage II patients more than 50 years old had better disease-free survival and local control at 5 years (p=0.004). None of the analyzed variables influenced the actuarial 5-year incidence of late complications. Conclusions: Results of this series suggest that the use of telecobalt equipment for EBR with doses up to 50 Gy at whole pelvis, prior to brachytherapy, is an acceptable technique for radiation therapy alone in the treatment of cervix cancer, especially in developing countries, including Brazil, where

  16. Remote Afterloading High Dose Rate (HDR) Endobronchial Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hyesook; Choi, Eun Kyung; Yi, Byong Yong; Kim, Won Dong; Kim, Woo Sung; Koh, Youn Suck [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    1991-12-15

    Authors described the remote afterloading endobronchial brachytherapy (EBBT) technique using the microSelectron HDR Ir-192 and the Asan Medical Center experience. Total 28 EBBT in 9 patients were performed since November 1989 and 24 EBBT in 8 patients were employed for palliation and 3 EBBT in 1 patient was treated curatively. Authors observed a significant relief of obstructive symptom with tumor regression in 7 patients out of 8 who were treated palliatively but one of them died of pulmonary congestion in 3 weeks after EBBT. One patient with prior therapy of extensive electrocautery expired within 1 day after 2nd EBBT procedure with massive hemorrhage from the lesion. EBBT procedure has been tolerable and can be performed as an outpatient.

  17. Remote Afterloading High Dose Rate (HDR) Endobronchial Brachytherapy

    International Nuclear Information System (INIS)

    Chang, Hyesook; Choi, Eun Kyung; Yi, Byong Yong; Kim, Won Dong; Kim, Woo Sung; Koh, Youn Suck

    1991-01-01

    Authors described the remote afterloading endobronchial brachytherapy (EBBT) technique using the microSelectron HDR Ir-192 and the Asan Medical Center experience. Total 28 EBBT in 9 patients were performed since November 1989 and 24 EBBT in 8 patients were employed for palliation and 3 EBBT in 1 patient was treated curatively. Authors observed a significant relief of obstructive symptom with tumor regression in 7 patients out of 8 who were treated palliatively but one of them died of pulmonary congestion in 3 weeks after EBBT. One patient with prior therapy of extensive electrocautery expired within 1 day after 2nd EBBT procedure with massive hemorrhage from the lesion. EBBT procedure has been tolerable and can be performed as an outpatient

  18. Computed Tomography–Guided Interstitial High-Dose-Rate Brachytherapy in Combination With Regional Positive Lymph Node Intensity-Modulated Radiation Therapy in Locally Advanced Peripheral Non–Small Cell Lung Cancer: A Phase 1 Clinical Trial

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Li; Zhang, Jian-wen; Lin, Sheng; Luo, Hui-Qun; Wen, Qing-Lian; He, Li-Jia; Shang, Chang-Ling; Ren, Pei-Rong; Yang, Hong-Ru; Pang, Hao-Wen; Yang, Bo; He, Huai-Lin [Department of Oncology, Affiliated Hospital of Luzhou Medical College, Luzhou (China); Chen, Yue, E-mail: chenyue5523@126.com [Department of Nuclear Medicine, Affiliated Hospital of Luzhou Medical College, Luzhou (China); Wu, Jing-Bo, E-mail: wjb6147@163.com [Department of Oncology, Affiliated Hospital of Luzhou Medical College, Luzhou (China)

    2015-08-01

    Purpose: To assess the technical safety, adverse events, and efficacy of computed tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy in combination with regional positive lymph node intensity modulated radiation therapy in patients with locally advanced peripheral non–small cell lung cancer (NSCLC). Methods and Materials: Twenty-six patients with histologically confirmed NSCLC were enrolled in a prospective, officially approved phase 1 trial. Primary tumors were treated with HDR brachytherapy. A single 30-Gy dose was delivered to the 90% isodose line of the gross lung tumor volume. A total dose of at least 70 Gy was administered to the 95% isodose line of the planning target volume of malignant lymph nodes using 6-MV X-rays. The patients received concurrent or sequential chemotherapy. We assessed treatment efficacy, adverse events, and radiation toxicity. Results: The median follow-up time was 28 months (range, 7-44 months). There were 3 cases of mild pneumothorax but no cases of hemothorax, dyspnea, or pyothorax after the procedure. Grade 3 or 4 acute hematologic toxicity was observed in 5 patients. During follow-up, mild fibrosis around the puncture point was observed on the CT scans of 2 patients, but both patients were asymptomatic. The overall response rates (complete and partial) for the primary mass and positive lymph nodes were 100% and 92.3%, respectively. The 1-year and 2-year overall survival (OS) rates were 90.9% and 67%, respectively, with a median OS of 22.5 months. Conclusion: Our findings suggest that HDR brachytherapy is safe and feasible for peripheral locally advanced NSCLC, justifying a phase 2 clinical trial.

  19. Radiochromic dye film studies for brachytherapy applications

    International Nuclear Information System (INIS)

    Martinez-Davalos, A.; Rodriguez-Villafuerte, M.; Diaz-Perches, R.; Arzamendi-Perez, S.

    2002-01-01

    Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate 137 Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200) with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study. (author)

  20. Evaluation of a Machine-Learning Algorithm for Treatment Planning in Prostate Low-Dose-Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Nicolae, Alexandru [Department of Physics, Ryerson University, Toronto, Ontario (Canada); Department of Medical Physics, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Morton, Gerard; Chung, Hans; Loblaw, Andrew [Department of Radiation Oncology, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Jain, Suneil; Mitchell, Darren [Department of Clinical Oncology, The Northern Ireland Cancer Centre, Belfast City Hospital, Antrim, Northern Ireland (United Kingdom); Lu, Lin [Department of Radiation Therapy, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Helou, Joelle; Al-Hanaqta, Motasem [Department of Radiation Oncology, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Heath, Emily [Department of Physics, Carleton University, Ottawa, Ontario (Canada); Ravi, Ananth, E-mail: ananth.ravi@sunnybrook.ca [Department of Medical Physics, Odette Cancer Center, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada)

    2017-03-15

    Purpose: This work presents the application of a machine learning (ML) algorithm to automatically generate high-quality, prostate low-dose-rate (LDR) brachytherapy treatment plans. The ML algorithm can mimic characteristics of preoperative treatment plans deemed clinically acceptable by brachytherapists. The planning efficiency, dosimetry, and quality (as assessed by experts) of preoperative plans generated with an ML planning approach was retrospectively evaluated in this study. Methods and Materials: Preimplantation and postimplantation treatment plans were extracted from 100 high-quality LDR treatments and stored within a training database. The ML training algorithm matches similar features from a new LDR case to those within the training database to rapidly obtain an initial seed distribution; plans were then further fine-tuned using stochastic optimization. Preimplantation treatment plans generated by the ML algorithm were compared with brachytherapist (BT) treatment plans in terms of planning time (Wilcoxon rank sum, α = 0.05) and dosimetry (1-way analysis of variance, α = 0.05). Qualitative preimplantation plan quality was evaluated by expert LDR radiation oncologists using a Likert scale questionnaire. Results: The average planning time for the ML approach was 0.84 ± 0.57 minutes, compared with 17.88 ± 8.76 minutes for the expert planner (P=.020). Preimplantation plans were dosimetrically equivalent to the BT plans; the average prostate V150% was 4% lower for ML plans (P=.002), although the difference was not clinically significant. Respondents ranked the ML-generated plans as equivalent to expert BT treatment plans in terms of target coverage, normal tissue avoidance, implant confidence, and the need for plan modifications. Respondents had difficulty differentiating between plans generated by a human or those generated by the ML algorithm. Conclusions: Prostate LDR preimplantation treatment plans that have equivalent quality to plans created

  1. Evaluation of a Machine-Learning Algorithm for Treatment Planning in Prostate Low-Dose-Rate Brachytherapy

    International Nuclear Information System (INIS)

    Nicolae, Alexandru; Morton, Gerard; Chung, Hans; Loblaw, Andrew; Jain, Suneil; Mitchell, Darren; Lu, Lin; Helou, Joelle; Al-Hanaqta, Motasem; Heath, Emily; Ravi, Ananth

    2017-01-01

    Purpose: This work presents the application of a machine learning (ML) algorithm to automatically generate high-quality, prostate low-dose-rate (LDR) brachytherapy treatment plans. The ML algorithm can mimic characteristics of preoperative treatment plans deemed clinically acceptable by brachytherapists. The planning efficiency, dosimetry, and quality (as assessed by experts) of preoperative plans generated with an ML planning approach was retrospectively evaluated in this study. Methods and Materials: Preimplantation and postimplantation treatment plans were extracted from 100 high-quality LDR treatments and stored within a training database. The ML training algorithm matches similar features from a new LDR case to those within the training database to rapidly obtain an initial seed distribution; plans were then further fine-tuned using stochastic optimization. Preimplantation treatment plans generated by the ML algorithm were compared with brachytherapist (BT) treatment plans in terms of planning time (Wilcoxon rank sum, α = 0.05) and dosimetry (1-way analysis of variance, α = 0.05). Qualitative preimplantation plan quality was evaluated by expert LDR radiation oncologists using a Likert scale questionnaire. Results: The average planning time for the ML approach was 0.84 ± 0.57 minutes, compared with 17.88 ± 8.76 minutes for the expert planner (P=.020). Preimplantation plans were dosimetrically equivalent to the BT plans; the average prostate V150% was 4% lower for ML plans (P=.002), although the difference was not clinically significant. Respondents ranked the ML-generated plans as equivalent to expert BT treatment plans in terms of target coverage, normal tissue avoidance, implant confidence, and the need for plan modifications. Respondents had difficulty differentiating between plans generated by a human or those generated by the ML algorithm. Conclusions: Prostate LDR preimplantation treatment plans that have equivalent quality to plans created

  2. SU-E-J-232: Feasibility of MRI-Based Preplan On Low Dose Rate Prostate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y; Tward, J; Rassiah-Szegedi, P; Zhao, H; Sarkar, V; Huang, L; Szegedi, M; Kokeny, K; Salter, B [University of Utah Huntsman Cancer Institute, Salt Lake City, UT (United States)

    2015-06-15

    Purpose: To investigate the feasibility of using MRI-based preplan for low dose rate prostate brachytherapy. Methods: 12 patients who received transrectal ultrasound (TRUS) guided prostate brachytherapy with Pd-103 were retrospectively studied. Our care-standard of the TRUS-based preplan served as the control. One or more prostate T2-weighted wide and/or narrow-field of view MRIs obtained within the 3 months prior to the implant were imported into the MIM Symphony software v6.3 (MIM Software Inc., Cleveland, OH) for each patient. In total, 37 MRI preplans (10 different image sequences with average thickness of 4.8mm) were generated. The contoured prostate volume and the seed counts required to achieve adequate dosimetric coverage from TRUS and MRI preplans were compared for each patient. The effects of different MRI sequences and image thicknesses were also investigated statistically using Student’s t-test. Lastly, the nomogram from the MRI preplan and TRUS preplan from our historical treatment data were compared. Results: The average prostate volume contoured on the TRUS and MRI were 26.6cc (range: 12.6∼41.3cc), and 27.4 cc (range: 14.3∼50.0cc), respectively. Axial MRI thicknesses (range: 3.5∼8.1mm) did not significantly affect the contoured volume or the number of seeds required on the preplan (R2 = 0.0002 and 0.0012, respectively). Four of the MRI sequences (AX-T2, AX-T2-Whole-Pelvis, AX-T2-FSE, and AXIALT2- Hi-Res) showed statistically significant better prostate volume agreement with TRUS than the other seven sequences (P <0.01). Nomogram overlay between the MRI and TRUS preplans showed good agreement; indicating volumes contoured on MRI preplan scan reliably predict how many seeds are needed for implant. Conclusion: Although MRI does not allow for determination of the actual implant geometry, it can give reliable volumes for seed ordering purposes. Our future work will investigate if MRI is sufficient to reliably replace TRUS preplanning in patients

  3. Brachytherapy in vulvar cancer: analysis of 18 patients

    International Nuclear Information System (INIS)

    Frezza, G.; Baldissera, A.; Bernardi, L.; Bunkheila, F.; Galuppi, A.; Salvi, F.

    1996-01-01

    INTRODUCTION: Vulvar cancer is a rather common neoplasm in elderly patients. Surgery, followed eventually by postoperative radiotherapy, is the treatment of choice. The results of exclusive radiotherapy (external beam irradiation and/or brachytherapy) are not well defined and in the recent literature only small series are reported. Radiotherapy however is the only therapeutic option in patients who are not fit for radical surgery. It is thus necessary to review its indications and its modalities. PATIENTS METHODS AND RESULTS: From 1990 to 1994 18 pts with a diagnosis of squamous cell carcinoma of the vulva have been submitted to brachytherapy. Age ranged from 60 to 92 years (mean age 76, 1 ys). 14 pts were treated at diagnosis (11 pts) or for recurrent disease after surgery (3 pts). In 8 of them brachytherapy (total dose 35-45 Gy, dose rate: 0,4-0,78 Gy/h) was preceded by external beam irradiation (Co60 or electron beam, 40-50 Gy to primary and inguinal nodes); 6 pts were treated with brachytherapy alone (58-60 Gy; dose rate 0,44-0,63 Gy/h). 4 pts underwent to brachytherapy alone for local recurrence after surgery and postoperative radiotherapy (total dose 45-60 Gy; dose rate 0,37-0,49 Gy/h). Brachytherapy was always performed with 192 Ir. Plastic tubes (2 to 5 lines) were used for single plane implantation of small exophytic lesions limited to the labia (8 cases); a perineal template (10 cases) was employed in lesions extended to the vaginal mucosa or involving the clitoris or the area of the perineum. (10(14)) pts treated at diagnosis are alive and free from local recurrence after 11-48 mos. 3 of them, treated with brachytherapy alone, have presented a nodal recurrence in the groin after 14, 15 and 27 mos. respectively. All of them are alive and free from disease after surgery and external radiotherapy. None of the pts treated for recurrent disease after surgery + external beam radiotherapy has achieved a local control. CONCLUSION: Brachytherapy alone or

  4. SU-E-J-116: Uncertainties Associated with Dose Summation of High-Dose Rate Brachytherapy and Intensity Modulated Radiotherapy for Gynecological Cases

    Energy Technology Data Exchange (ETDEWEB)

    Kauweloa, K; Bergamo, A; Gutierrez, A; Stathakis, S; Papanikolaou, N; Kirby, N [University of Texas HSC SA, San Antonio, TX (United States); Cancer Therapy and Research Center, San Antonio, TX (United States); Mavroidis, P [University of North Carolina, Chapel Hill, NC (United States)

    2015-06-15

    Purpose: Determining the cumulative dose distribution (CDD) for gynecological patients treated with both high-dose rate (HDR) brachytherapy and intensity-modulated radiotherapy (IMRT) is challenging. The purpose of this work is to study the uncertainty of performing this with a structure-guided deformable (SGD) approach in Velocity. Methods: For SGD, the Hounsfield units inside specified contours are overridden to set uniform values. Deformable image registration (DIR) is the run on these process images, which forces the DIR to focus on these contour boundaries. 18 gynecological cancer patients were used in this study. The original bladder and rectum planning contours for these patients were used to drive the SGD. A second set of contours were made of the bladder by the same person with the intent of carefully making them completely consistent with each other. This second set was utilized to evaluate the spatial accuracy of the SGD. The determined spatial accuracy was then multiplied by the local dose gradient to determine a dose uncertainty associated with the SGD dose warping. The normal tissue complication probability (NTCP) was then calculated for each dose volume histogram (DVH) that included four different probabilistic uncertainties associated with the spatial errors (e.g., 68.3% and 95.4%). Results: The NTCPs for each DVH (e.g., NTCP-−95.4%, NTCP-−68.3%, NTCP-68.3%, NTCP-95.4%) differed amongst patients. All patients had an NTCP-−95.4% close to 0%, while NTCP-95.4% ranged from 0.67% to 100%. Nine patients had an NTCP-−95.4% less than 50% while the remaining nine patients had NTCP-95.4% greater than 50%. Conclusion: The uncertainty associated with this CDD technique renders a large NTCP uncertainty. Thus, it is currently not practical for clinical use. The two ways to improve this would be to use more precise contours to drive the SGD and to use a more accurate DIR algorithm.

  5. A survey of current clinical practice in permanent and temporary prostate brachytherapy: 2010 update.

    Science.gov (United States)

    Buyyounouski, Mark K; Davis, Brian J; Prestidge, Bradley R; Shanahan, Thomas G; Stock, Richard G; Grimm, Peter D; Demanes, D Jeffrey; Zaider, Marco; Horwitz, Eric M

    2012-01-01

    To help establish patterns of care and standards of care of interstitial permanent low-dose-rate (LDR) and temporary high-dose-rate brachytherapy for prostate cancer and to compare the results with a similar 1998 American Brachytherapy Society (ABS) survey. A comprehensive questionnaire intended to survey specific details of current clinical brachytherapy practice was provided to the participants of the seventh ABS Prostate Brachytherapy School. Responses were tabulated and descriptive statistics are reported. Sixty-five brachytherapy practitioners responded to the survey. Eighty-nine percent (89%) of respondents performed LDR and 49% perform high-dose-rate brachytherapy. The median number of years of experience for LDR brachytherapists increased from 5 to 10 years over the course of the 12 years since the preceding survey. Compared with the first ABS, a smaller proportion of respondents received formal brachytherapy residency training (43% vs. 56%) or formal "hands-on" brachytherapy training (15% vs. 63%). There has been a marked decline in the utilization of the Mick applicator (Mick Radio-Nuclear Instruments, Inc., Mount Vernon, NY, USA) (60% vs. 28%) and an increase in the use of stranded seeds (40% vs. 11%). Compliance with postimplant dosimetry was higher in the 2010 survey. This survey does suggest an evolution in the practice of LDR brachytherapy since 1998 and aids in identifying aspects that require further progress or investigation. ABS guidelines and other practice recommendations appear to impact the practice of brachytherapy. Copyright © 2012 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  6. Effect of brachytherapy technique and patient characteristics on cervical cancer implant dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Anker, Christopher J., E-mail: chris.anker@hci.utah.edu [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States); O' Donnell, Kristen [Department of Radiation Oncology, The University of Arizona, Tucson, AZ (United States); Boucher, Kenneth M. [Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT (United States); Gaffney, David K. [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States)

    2013-01-01

    Our purpose was to evaluate the relationship between brachytherapy technique and patient characteristics on dose to organs-at-risk (OARs) in patients undergoing high dose rate (HDR) brachytherapy for cervical cancer. From 1998 to 2008, 31 patients with cervical cancer with full dosimetric data were identified who received definitive external-beam radiation and HDR brachytherapy with tandem and ovoid applicators. Doses were recorded at point A, the International Commission on Radiation Units and Measurements (ICRU)-38 rectal point, the ICRU-38 bladder point, the vaginal surface, and the pelvic sidewall. Generalized estimating equations were used to determine the significance of changes in OAR to point A dose ratios with differences in brachytherapy technique or patient characteristics. Patients underwent a median of 5 brachytherapy procedures (range, 3 to 5), with a total of 179 procedures for 31 patients. For all brachytherapy treatments, the average ratios between the doses for the rectal, bladder, vaginal surface, and pelvic sidewall reference points to those at point A were 0.49, 0.59, 1.15, and 0.17, respectively. In general, decreased OAR dose was associated with a lower stage, younger age, increased ovoid size, increased tandem length, and earlier implant number. Increased tandem curvature significantly increased bladder dose and decreased rectal dose. Intravenous anesthesia usage was not correlated with improved dosimetry. This study allowed identification of patient and procedure characteristics influencing OAR dosing. Although the advent of 3-dimensional (3D) image-guided brachytherapy will bring new advances in treatment optimization, the actual technique involved at the time of the brachytherapy implant procedure will remain important.

  7. Study of the radiation levels in low dose rate brachytherapy zones of the National Institute of Neoplastic Illnesses

    International Nuclear Information System (INIS)

    Figueroa J, N.; Mora Y, B.

    2006-01-01

    The present study has as objective to evaluate the radiation levels of the Brachytherapy work areas of low dose rate (Gammateque, nurses station and of hospitalization rooms of patients RIC of 4th, 5th Floor-East) and to estimate the effective dose of the occupationally exposed personnel and the public in general. The measurements of the dose rate in these areas, were registered with a radiations monitor Inspector trademark, during a period of 60 days, without altering the routinary work conditions. The more high levels of environmental dose equivalent rate registered in the different work areas its are of 1.41 and 47.78 μSv/h rooms 1 and 2 in the Gammateque environments, in the hospitalization rooms of the 4th and 5th floor in the point 1 are of 40.77 and 23.67, μSv/h respectively and in the point 2 are of 129.19 and 39.93, μSv/h respectively, and in the nurses station of the 4th and 5th floor its are respectively of 7.62 u Sv/h and 0.45 u Sv/h. According to the carried out measurements and the permanency in the work place is possible to estimate the effective dose involved to the occupationally exposed personnel. The personnel that works in Gammateque could be receiving respectively as maximum dose 0.61 mSv/month, and the personnel that works in the nurses station of 13.17 and 0.78 mSv/year in the 4th and 5th floor. These registered differences among the two floors are due to that the 5th floor counts with the shielding systems (screen) contrary to the 4th, another of the factors is the distribution form of the patient beds RIC. We should have present that the radiation levels although in some cases it is very high, however, they are below of the permissible limits according to standards, but it is still possible to reduce even more, the radiation levels in the critical points fulfilling with the ALARA principle. (Author)

  8. Image Guided Cervical Brachytherapy: 2014 Survey of the American Brachytherapy Society

    Energy Technology Data Exchange (ETDEWEB)

    Grover, Surbhi, E-mail: Surbhi.grover@uphs.upenn.edu [Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Harkenrider, Matthew M. [Department of Radiation Oncology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois (United States); Cho, Linda P. [Department of Radiation Oncology, Brigham & Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Erickson, Beth [Department Radiation Oncology, Froedtert Hospital and Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Small, Christina [Department of Public Health Sciences, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois (United States); Small, William [Department of Radiation Oncology, Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois (United States); Viswanathan, Akila N. [Department of Radiation Oncology, Brigham & Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States)

    2016-03-01

    Purpose: To provide an update of the 2007 American brachytherapy survey on image-based brachytherapy, which showed that in the setting of treatment planning for gynecologic brachytherapy, although computed tomography (CT) was often used for treatment planning, most brachytherapists used point A for dose specification. Methods and Materials: A 45-question electronic survey on cervical cancer brachytherapy practice patterns was sent to all American Brachytherapy Society members and additional radiation oncologists and physicists based in the United States between January and September 2014. Responses from the 2007 survey and the present survey were compared using the χ{sup 2} test. Results: There were 370 respondents. Of those, only respondents, not in training, who treat more than 1 cervical cancer patient per year and practice in the United States, were included in the analysis (219). For dose specification to the target (cervix and tumor), 95% always use CT, and 34% always use MRI. However, 46% use point A only for dose specification to the target. There was a lot of variation in parameters used for dose evaluation of target volume and normal tissues. Compared with the 2007 survey, use of MRI has increased from 2% to 34% (P<.0001) for dose specification to the target. Use of volume-based dose delineation to the target has increased from 14% to 52% (P<.0001). Conclusion: Although use of image-based brachytherapy has increased in the United States since the 2007 survey, there is room for further growth, particularly with the use of MRI. This increase may be in part due to educational initiatives. However, there is still significant heterogeneity in brachytherapy practice in the United States, and future efforts should be geared toward standardizing treatment.

  9. Gold nanoparticle-aided brachytherapy with vascular dose painting: estimation of dose enhancement to the tumor endothelial cell nucleus.

    Science.gov (United States)

    Ngwa, Wilfred; Makrigiorgos, G Mike; Berbeco, Ross I

    2012-01-01

    Theoretical microdosimetry at the subcellular level is employed in this study to estimate the dose enhancement to tumor endothelial cell nuclei, caused by radiation-induced photo/Auger electrons originating from gold nanoparticles (AuNPs) targeting the tumor endothelium, during brachytherapy. A tumor vascular endothelial cell (EC) is modeled as a slab of 2 μm (thickness) × 10 μm (length) × 10 μm (width). The EC contains a nucleus of 5 μm diameter and thickness of 0.5-1 μm, corresponding to nucleus size 5%-10% of cellular volume, respectively. Analytic calculations based on the electron energy loss formula of Cole were carried out to estimate the dose enhancement to the nucleus caused by photo/Auger electrons from AuNPs attached to the exterior surface of the EC. The nucleus dose enhancement factor (nDEF), representing the ratio of the dose to the nucleus with and without the presence of gold nanoparticles was calculated for different AuNP local concentrations. The investigated concentration range considers the potential for significantly higher local concentration near the EC due to preferential accumulation of AuNP in the tumor vasculature. Four brachytherapy sources: I-125, Pd-103, Yb-169, and 50 kVp x-rays were investigated. For nucleus size of 10% of the cellular volume and AuNP concentrations ranging from 7 to 140 mg/g, brachytherapy sources Pd-103, I-125, 50 kVp, and Yb-169 yielded nDEF values of 5.6-73, 4.8-58.3, 4.7-56.6, and 3.2-25.8, respectively. Meanwhile, for nucleus size 5% of the cellular volume in the same concentration range, Pd-103, I-125, 50 kVp, and Yb-169 yielded nDEF values of 6.9-79.2, 5.1-63.2, 5.0-61.5, and 3.3-28.3, respectively. The results predict that a substantial dose boost to the nucleus of endothelial cells can be achieved by applying tumor vasculature-targeted AuNPs in combination with brachytherapy. Such vascular dose boosts could induce tumor vascular shutdown, prompting extensive tumor cell death.

  10. Gold nanoparticle-aided brachytherapy with vascular dose painting: Estimation of dose enhancement to the tumor endothelial cell nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Ngwa, Wilfred; Makrigiorgos, G. Mike; Berbeco, Ross I. [Department of Radiation Oncology, Division of Medical Physics and Biophysics, Brigham and Women' s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2012-01-15

    Purpose: Theoretical microdosimetry at the subcellular level is employed in this study to estimate the dose enhancement to tumor endothelial cell nuclei, caused by radiation-induced photo/Auger electrons originating from gold nanoparticles (AuNPs) targeting the tumor endothelium, during brachytherapy. Methods: A tumor vascular endothelial cell (EC) is modeled as a slab of 2 {mu}m (thickness) x 10 {mu}m (length) x 10 {mu}m (width). The EC contains a nucleus of 5 {mu}m diameter and thickness of 0.5-1 {mu}m, corresponding to nucleus size 5%-10% of cellular volume, respectively. Analytic calculations based on the electron energy loss formula of Cole were carried out to estimate the dose enhancement to the nucleus caused by photo/Auger electrons from AuNPs attached to the exterior surface of the EC. The nucleus dose enhancement factor (nDEF), representing the ratio of the dose to the nucleus with and without the presence of gold nanoparticles was calculated for different AuNP local concentrations. The investigated concentration range considers the potential for significantly higher local concentration near the EC due to preferential accumulation of AuNP in the tumor vasculature. Four brachytherapy sources: I-125, Pd-103, Yb-169, and 50 kVp x-rays were investigated. Results: For nucleus size of 10% of the cellular volume and AuNP concentrations ranging from 7 to 140 mg/g, brachytherapy sources Pd-103, I-125, 50 kVp, and Yb-169 yielded nDEF values of 5.6-73, 4.8-58.3, 4.7-56.6, and 3.2-25.8, respectively. Meanwhile, for nucleus size 5% of the cellular volume in the same concentration range, Pd-103, I-125, 50 kVp, and Yb-169 yielded nDEF values of 6.9-79.2, 5.1-63.2, 5.0-61.5, and 3.3-28.3, respectively. Conclusions: The results predict that a substantial dose boost to the nucleus of endothelial cells can be achieved by applying tumor vasculature-targeted AuNPs in combination with brachytherapy. Such vascular dose boosts could induce tumor vascular shutdown, prompting

  11. Dose rate considerations in brachytherapy: biological equivalence of LDR and HDR

    International Nuclear Information System (INIS)

    Orton, C.G.

    1994-01-01

    The linear-quadratic model for cell survival and bioeffect doses is discussed and equations for low dose rate (LDR), high dose rate (HDR) and intermediate situations are presented. The model, when used to define LDR and single fractions of HDR, shows, that these correspond to irradiations lasting longer than about 14 hours or shorter than about 0.7 hours, respectively. It is shown that, for HDR to be as safe and effective as LDR, the dose-rate effect of LDR has to be replaced by the fractionation-effect of HDR. This is necessary in order to take advantage of the differential repair characteristics between late-reacting normal tissue and tumor cells at low doses and low dose rates. Using the linear-quadratic model to simulate repair mathematically, it is shown that the number of fractions required is highly dependent upon what parameters are assumed for normal tissues and tumor, as well as whether or not there is any physical advantage gained by conversion from LDR to HDR. (author). 20 refs., 7 figs

  12. Radiobiological responses for two cell lines following continuous low dose-rate (CLDR) and pulsed dose rate (PDR) brachytherapy

    International Nuclear Information System (INIS)

    Hanisch, Per Henrik; Furre, Torbjoern; Olsen, Dag Rune; Pettersen, Erik O.

    2007-01-01

    The iso-effective irradiation of continuous low-dose-rate (CLDR) irradiation was compared with that of various schedules of pulsed dose rate (PDR) irradiation for cells of two established human lines, T-47D and NHIK 3025. Complete single-dose response curves were obtained for determination of parameters α and β by fitting of the linear quadratic formula. Sublethal damage repair constants μ and T 1/2 were determined by split-dose recovery experiments. On basis of the acquired parameters of each cell type the relative effectiveness of the two regimens of irradiation (CLDR and PDR) was calculated by use of Fowler's radiobiological model for iso-effect irradiation for repeated fractions of dose delivered at medium dose rates. For both cell types the predicted and observed relative effectiveness was compared at low and high iso-effect levels. The results indicate that the effect of PDR irradiation predicted by Fowler's model is equal to that of CLDR irradiation for both small and large doses with T-47D cells. With NHIK 3025 cells PDR irradiation induces a larger effect than predicted by the model for small doses, while it induces the predicted effect for high doses. The underlying cause of this difference is unclear, but cell-cycle parameters, like G2-accumulation is tested and found to be the same for the two cell lines

  13. Definitive Brachytherapy for Kaposi's Sarcoma

    International Nuclear Information System (INIS)

    Williams, A.; Ezzell, G.; Zalupski, M.; Fontanesi, J.

    1996-01-01

    Purpose: To assess the efficacy and possible complications in patients diagnosed with Kaposi's sarcoma and treated with definitive brachytherapy. Methods and Materials: Between January, 1995 and December, 1995, four patients with Kaposi's sarcoma (KS) were treated with brachytherapy. Three patients, all with positive HIV status were treated using Iridium 192 (Ir-192) sources via a high-dose rate remote afterloader. One patient with endemic KS was treated using the application of catheters loaded with Californium 252. Eight sites were treated and included scalp, feet, nose, penis, hand, neck, and back. Dose rate for Ir-192 was 330cGy/fx to a total dose of 990cGy. The Californium was delivered as 100nGy/b.i.d. to a total dose of 900nGy. Follow-up as ranged from 2-6 months. Results: All four patients remain alive. Seven of eight sites have had complete clinical response and each patient has reported durable pain relief that has not subsided through last follow-up of 1/96. Two of eight sites, both treated with surface mold technique with Californium 252 developed moist desquamation. The remaining six sites did not demonstrate significant toxicity. Conclusion: Brachytherapy can offer Kaposi's sarcoma patients results that are equivalent to external beam radiation therapy, with minimal complications, a shorter treatment time and potential cost effectiveness

  14. High-Dose-Rate Brachytherapy Alone for Localized Prostate Cancer in Patients at Moderate or High Risk of Biochemical Recurrence

    Energy Technology Data Exchange (ETDEWEB)

    Hoskin, Peter [Cancer Centre, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom); Rojas, Ana, E-mail: arc03@btconnect.com [Cancer Centre, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom); Lowe, Gerry; Bryant, Linda; Ostler, Peter; Hughes, Rob; Milner, Jessica; Cladd, Helen [Cancer Centre, Mount Vernon Hospital, Northwood, Middlesex (United Kingdom)

    2012-03-15

    Purpose: To evaluate genitourinary (GU) and gastrointestinal (GI) morbidity and biochemical control of disease in patients with localized prostate adenocarcinoma treated with escalating doses per fraction of high-dose rate brachytherapy alone. Methods and Materials: A total of 197 patients were treated with 34 Gy in four fractions, 36 Gy in four fractions, 31.5 Gy in three fractions, or 26 Gy in two fractions. Median follow-up times were 60, 54, 36, and 6 months, respectively. Results: Incidence of early Grade {>=} 3 GU morbidity was 3% to 7%, and Grade 4 was 0% to 4%. During the first 12 weeks, the highest mean International Prostate Symptom Score (IPSS) value was 14, and between 6 months and 5 years it was 8. Grade 3 or 4 early GI morbidity was not observed. The 3-year actuarial rate of Grade 3 GU was 3% to 16%, and was 3% to 7% for strictures requiring surgery (4-year rate). An incidence of 1% Grade 3 GI events was seen at 3 years. Late Grade 4 GU or GI events were not observed. At 3 years, 99% of patients with intermediate-risk and 91% with high-risk disease were free of biochemical relapse (log-rank p = 0.02). Conclusions: There was no significant difference in urinary and rectal morbidity between schedules. Biochemical control of disease in patients with intermediate and high risk of relapse was good.

  15. Calibration procedure for thermoluminescent dosemeters in water absorbed doses for Iridium-192 high dose rate sources

    International Nuclear Information System (INIS)

    Reyes Cac, Franky Eduardo

    2004-10-01

    Thermoluminescent dosimeters are used in brachytherapy services quality assurance programs, with the aim of guaranteeing the correct radiation dose supplied to cancer patients, as well as with the purpose of evaluating new clinical procedures. This work describes a methodology for thermoluminescent dosimeters calibration in terms of absorbed dose to water for 192 Ir high dose rate sources. The reference dose used is measured with an ionization chamber previously calibrated for 192 Ir energy quality, applying the methodology proposed by Toelli. This methodology aims to standardizing the procedure, in a similar form to that used for external radiotherapy. The work evolves the adaptation of the TRS-277 Code of the International Atomic Energy Agency, for small and big cavities, through the introduction for non-uniform experimental factor, for the absorbed dose in the neighborhood of small brachytherapy sources. In order to simulate a water medium around the source during the experimental work, an acrylic phantom was used. It guarantees the reproducibility of the ionization chamber and the thermoluminescent dosimeter's location in relation to the radiation source. The values obtained with the ionization chamber and the thermoluminescent dosimeters, exposed to a 192 Ir high dose rate source, were compared and correction factors for different source-detector distances were determined for the thermoluminescent dosimeters. A numeric function was generated relating the correction factors and the source-detector distance. These correction factors are in fact the thermoluminescent dosimeter calibration factors for the 192 Ir source considered. As a possible application of this calibration methodology for thermoluminescent dosimeters, a practical range of source-detector distances is proposed for quality control of 192 Ir high dose rate sources. (author)

  16. Brachytherapy - not pulsed and low rate brachytherapy. Medical radiation protection - ED 4248

    International Nuclear Information System (INIS)

    2008-06-01

    After an indication of authorizations required to perform brachytherapy, this sheet indicates the concerned personnel, indicates the different treatment steps, briefly describes the risk related to ionizing radiations, indicates the various aspects of risk assessment and of determination of exposure levels (definition of controlled and monitored areas, personnel classification, possible methods for dose monitoring), presents the strategy for risk management (rules regarding risk reduction, technical measures regarding the installation, individual technical measures, training and information, prevention and medical monitoring) and how this risk management can be assessed

  17. Calculating of Dose Distribution in Tongue Brachytherapy by Different Radioisotopes using Monte Carlo Simulation and Comparing by Experimental Data

    Directory of Open Access Journals (Sweden)

    Banafsheh Zeinali Rafsanjani

    2011-06-01

    Full Text Available Introduction: Among different kinds of oral cavity cancers, the frequency of tongue cancer occurrence is more significant. Brachytherapy is the most common method to cure tongue cancers. Long sources are used in different techniques of tongue brachytherapy. The objective of this study is to asses the dose distribution around long sources, comparing different radioisotopes as brachytherapy sources, measuring the homogeneity of delivered dose to treatment volume and also comparing mandible dose and dose of tongue in the regions near the mandible with and without using shield. Material and Method: The Monte Carlo code MCNP4C was used for simulation. The accuracy of simulation was verified by comparing the results with experimental data. The sources like Ir-192, Cs-137, Ra-226, Au-198, In-111 and Ba-131 were simulated and the position of sources was determined by Paris system. Results: The percentage of mandible dose reduction with use of 2 mm Pb shield for the sources mentioned above were: 35.4%, 20.1%, 86.6%, 32.24%, 75.6%, and 36.8%. The tongue dose near the mandible with use of shied did not change significantly. The dose homogeneity from the most to least was obtained from these sources: Cs-137, Au-198, Ir-192, Ba-131, In-111 and Ra-226. Discussion and Conclusion: Ir-192 and Cs-137 were the best sources for tongue brachytherapy treatment but In-111 and Ra-226 were not suitable choices for tongue brachytherapy. The sources like Au-198 and Ba-131 had rather the same performance as Ir-192

  18. Oncological outcome, complications, lower urinary tract symptoms, and health-related quality of life after low-dose-rate salvage brachytherapy for recurrent prostate cancer following primary radiotherapy: a report of 8 cases

    Directory of Open Access Journals (Sweden)

    Makito Miyake

    2017-07-01

    Full Text Available Purpose: We evaluated our experience with low-dose-rate salvage brachytherapy for local recurrence after primary prostate radiotherapy, and described the changes in lower urinary tract symptoms and health-related quality of life. Material and methods: Between 2011 and 2016, eight men with local recurrence after primary prostate radiotherapy underwent iodine-125 salvage brachytherapy with a prescribed dose of 110 or 145 Gy. Recurrence-free survival was evaluated with a post-treatment prostate-specific antigen profile. The toxicity and changes in lower urinary tract symptoms and health-related quality of life during the follow-up were evaluated on the Common Terminology Criteria for Adverse Events version 4.0, International Prostate Symptom Score, Short Form-8, and Expanded Prostate Cancer Index Composite, respectively. Results: The median follow-up was 12.2 months (range, 8.3-71.9 after salvage brachytherapy. Of all eight patients, two (25% experienced treatment failure, one of whom developed left seminal vesicle recurrence 36 months after salvage brachytherapy for the right seminal vesicle recurrence, while the other developed bone metastases after 6 months. The International Prostate Symptom Scores peaked at 3 months, and returned to baseline by 6 months. The scores of all domains of health-related quality of life remained unchanged during the 12-month follow-up after salvage brachytherapy. Early grade ≤ 2 genitourinary toxicity was observed in five patients (63%, and late grade 2 gastrointestinal toxicity in one patient (13% having persistent diarrhea. No patient required intermittent catheterization and no grade 3 or greater toxicity occurred during follow-up. Conclusions: The present study is our experiment of eight patients undergoing salvage brachytherapy, suggesting that this modality is noninvasive, safe, and an effective salvage local treatment in selected patients. To our knowledge, this is the first study to evaluate lower urinary

  19. High-dose-rate-intracavitary brachytherapy applications and the difference in the bladder and rectum doses: A study from rural centre of Maharashatra, India

    Directory of Open Access Journals (Sweden)

    Jain Vandana

    2007-01-01

    Full Text Available Aim : To report the difference in the bladder and rectum doses with different applications by the radiotherapists in the same patient of the carcinoma of the uterine cervix treated by multiple fractions of high-dose-rate (HDR intracavitary brachytherapy (ICBT. Materials and Methods : Between January 2003 to December 2004, a total of 60 cases of the carcinoma uterine cervix were selected randomly for the retrospective analyses. All 60 cases were grouped in six groups according to the treating radiotherapist who did the HDR-ICBT application. Three radiotherapists were considered for this study, named A, B and C. Ten cases for each radiotherapist in whom all three applications were done by the same radiotherapist. And 10 cases for each radiotherapist with shared applications in the same patient (A+B, A+C and B+C. The bladder and rectal doses were calculated in reference to point "A" dose and were limited to 80% of prescribed point "A" dose, as per ICRU-38 recommendations. Received dose grouped in three groups- less then 80% (< 80%, 80-100% and above 100% (>100%. A total of 180 applications for 60 patients were calculated for the above analyses. Results : There is a lot of difference in the bladder and rectal doses with the application by the different radiotherapists, even in the same patient with multiple fractions of HDR-ICBT. Applications by ′A′ radiotherapist were within the limits in the self as well as in the shared groups more number of times, by ′B′ radiotherapist was more times exceeding the limit and by ′C′ radiotherapist doses were in between the A and B. Discussion and Conclusion : For the rectal and bladder doses most important factors are patient′s age, disease stage, duration between EBRT and HDR-ICRT and patient anatomy, but these differences can be minimized to some extent by careful application, proper packing and proper fixation.

  20. Effect of improved TLD dosimetry on the determination of dose rate constants for 125I and 103Pd brachytherapy seeds

    International Nuclear Information System (INIS)

    Rodriguez, M.; Rogers, D. W. O.

    2014-01-01

    Purpose: To more accurately account for the relative intrinsic energy dependence and relative absorbed-dose energy dependence of TLDs when used to measure dose rate constants (DRCs) for 125 I and 103 Pd brachytherapy seeds, to thereby establish revised “measured values” for all seeds and compare the revised values with Monte Carlo and consensus values. Methods: The relative absorbed-dose energy dependence, f rel , for TLDs and the phantom correction, P phant , are calculated for 125 I and 103 Pd seeds using the EGSnrc BrachyDose and DOSXYZnrc codes. The original energy dependence and phantom corrections applied to DRC measurements are replaced by calculated (f rel ) −1 and P phant values for 24 different seed models. By comparing the modified measured DRCs to the MC values, an appropriate relative intrinsic energy dependence, k bq rel , is determined. The new P phant values and relative absorbed-dose sensitivities, S AD rel , calculated as the product of (f rel ) −1 and (k bq rel ) −1 , are used to individually revise the measured DRCs for comparison with Monte Carlo calculated values and TG-43U1 or TG-43U1S1 consensus values. Results: In general, f rel is sensitive to the energy spectra and models of the brachytherapy seeds. Values may vary up to 8.4% among 125 I and 103 Pd seed models and common TLD shapes. P phant values depend primarily on the isotope used. Deduced (k bq rel ) −1 values are 1.074 ± 0.015 and 1.084 ± 0.026 for 125 I and 103 Pd seeds, respectively. For (1 mm) 3 chips, this implies an overall absorbed-dose sensitivity relative to 60 Co or 6 MV calibrations of 1.51 ± 1% and 1.47 ± 2% for 125 I and 103 Pd seeds, respectively, as opposed to the widely used value of 1.41. Values of P phant calculated here have much lower statistical uncertainties than literature values, but systematic uncertainties from density and composition uncertainties are significant. Using these revised values with the literature’s DRC measurements, the