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Sample records for beam radiotherapy ebrt

  1. Intraoperative radiotherapy (IORT combined with external beam radiotherapy (EBRT for soft-tissue sarcomas – a retrospective evaluation of the Homburg experience in the years 1995–2007

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    Bleuzen Caroline

    2009-08-01

    Full Text Available Abstract Purpose To retrospectively evaluate the results after a regimen of surgery, IORT (intraoperative radiotherapy, and EBRT (external beam radiotherapy for soft-tissue sarcomas Methods 38 consecutive patients underwent IORT for soft-tissue sarcoma; 29 were treated for primary tumours, 9 for recurrences. There were 14 cases with liposarcomas, 8 with leiomyosarcomas, 7 with malignant fibrous histiocytomas. 27/38 tumours were located in the extremities, the remaining ones in the retroperitoneum or the chest. Radical resection was attempted in all patients; a R0-resection was achieved in 15/38 patients, R1 in 12/38 pats and R2 in 4/38 pats. IORT was performed using a J-125 source and a HDR (high dose rate afterloading machine after suturing silicone flaps to the tumour bed. The total dose applied ranged from 8–15 Gy/0.5 cm tissue depth measured from the flap surface. After wound healing external beam radiotherapy (EBRT was applied in 31/38 patients with total doses of 23–56 Gy dependent on resection status and wound situation. The mean duration of follow-up was 2.3 years. Results A local recurrence was found in 10/36 patients, lymph node metastases in 2/35, and distant metastases in 6/35 patients. The actuarial local control rate was 63%/5 years. The overall survival rate was 57%/5 years. There was no statistically significant difference between the results after treatment for primaries or for recurrences. Late toxicity to the skin was found in 13/31 patients, wound healing problems in 5/31 patients. A neuropathy was never seen. Conclusion The combination of surgery, IORT, and EBRT yields favourable local control and survival data which are well within the range of the results reported in the literature. The complication rates, however, are considerable although the complications are not severe, they should be taken into account when therapy decisions are made.

  2. Modulated photon radiotherapy (XMRT): an algorithm for the simultaneous optimization of photon beamlet energy and intensity in external beam radiotherapy (EBRT) planning

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    McGeachy, Philip; Villarreal-Barajas, Jose Eduardo; Zinchenko, Yuriy; Khan, Rao

    2016-02-01

    This is a proof of principle study on an algorithm for optimizing external beam radiotherapy in terms of both photon beamlet energy and fluence. This simultaneous beamlet energy and fluence optimization is denoted modulated photon radiotherapy (XMRT). XMRT is compared with single-energy intensity modulated radiotherapy (IMRT) for five clinically relevant test geometries to determine whether treating beamlet energy as a decision variable improves the dose distributions. All test geometries were modelled in a cylindrical water phantom. XMRT optimized the fluence for 6 and 18 MV beamlets while IMRT optimized with only 6 MV and only 18 MV. CERR (computational environment for radiotherapy research) was used to calculate the dose deposition matrices and the resulting dose for XMRT and IMRT solutions. Solutions were compared via their dose volume histograms and dose metrics, such as the mean, maximum, and minimum doses for each structure. The homogeneity index (HI) and conformity number (CN) were calculated to assess the quality of the target dose coverage. Complexity of the resulting fluence maps was minimized using the sum of positive gradients technique. The results showed XMRT’s ability to improve healthy-organ dose reduction while yielding comparable coverage of the target relative to IMRT for all geometries. All three energy-optimization approaches yielded similar HI and CNs for all geometries, as well as a similar degree of fluence map complexity. The dose reduction provided by XMRT was demonstrated by the relative decrease in the dose metrics for the majority of the organs at risk (OARs) in all geometries. Largest reductions ranged between 5% to 10% in the mean dose to OARs for two of the geometries when compared with both single-energy IMRT schemes. XMRT has shown potential dosimetric benefits through improved OAR sparing by allowing beam energy to act as a degree of freedom in the EBRT optimization process.

  3. The Degree of Lipiodol Accumulation Can Be an Indicator of Successful Treatment for Unresectable Hepatocellular Carcinoma (HCC) Patients - in the Case of Transcatheter Arterial Chemoembolization (TACE) and External Beam Radiotherapy (EBRT)

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    Yang, Ping; Zeng, Zhao-Chong; Wang, Bin-Liang; Zhang, Jian-Ying; Fan, Jia; Zhou, Jian; Hu, Yong

    2016-01-01

    Purpose: Transcatheter arterial chemoembolization (TACE) in combination with external beam radiotherapy (EBRT) results in improved survival due to better local control in patients with unresectable hepatocellular carcinoma (HCC). The purpose of this study was to investigate lipiodol accumulation, as it reflects tumor burden and is a potential prognostic factor, in HCC patients treated with TACE/EBRT. Methods and Materials: We retrospectively studied 147 patients with unresectable HCC treated with TACE and EBRT. Clinical features, adverse reactions, and prognostic factors were analyzed. All patients were treated with TACE 1-6 times in combination with EBRT (44-66 Gy) in dose of 2 Gy/fraction given once a day five times a week. Tumor status and laboratory findings were followed. The degree of lipiodol accumulation was assessed by computed tomography before EBRT, and was categorized as either complete/intense or low/moderate. Results: The response rate of tumor size after EBRT was 68.2%, median survival was 23.1 months, and overall survival rates were 86.6%, 49.2%, and 28.2% at 1, 2, and 3 years, respectively. Univariate analysis showed that lower hemoglobin levels, higher alkaline phosphatase levels, Child-Pugh B, negative alpha-fetoprotein (AFP) response after EBRT, poor treatment response after EBRT, tumor diameter >10 cm, and poor lipiodol accumulation were unfavorable prognostic factors. On multivariate analysis, higher hemoglobin levels, Child-Pugh A, decreased AFP levels after treatment, Helical Tomotherapy (HT) and intense lipiodol accumulation after TACE were significant favorable predictors. Conclusions: The degree of lipiodol accumulation before EBRT is a prognostic factor in patients with unresectable HCC. Increased AFP levels after EBRT are always associated with poor survival. HT is recommended as a potentially better EBRT modality than three-dimensional conformal radiation therapy (3D-CRT). PMID:27471557

  4. Analysis of health related quality of life (HRQoL) of patients with clinically localized prostate cancer, one year after treatment with external beam radiotherapy (EBRT) alone versus EBRT and high dose rate brachytherapy (HDRBT)

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    Prostate cancer is the leading form of cancer diagnosed among North American men. Most patients present with localized disease, which can be effectively treated with a variety of different modalities. These are associated with widely different acute and late effects, which can be both physical and psychological in nature. HRQoL concerns are therefore important for these patients for selecting between the different treatment options. One year after receiving radiotherapy for localised prostate cancer 117 patients with localized prostate cancer were invited to participate in a quality of life (QoL) self reported survey. 111 patients consented and participated in the survey, one year after completion of their treatment. 88 patients received EBRT and 23 received EBRT and HDRBT. QoL was compared in the two groups by using a modified version of Functional Assessment of Cancer Therapy-Prostate (FACT-P) survey instrument. One year after completion of treatment, there was no significant difference in overall QoL scores between the two groups of patients. For each component of the modified FACT-P survey, i.e. physical, social/family, emotional, and functional well-being; there were no statistically significant differences in the mean scores between the two groups. In prostate cancer patients treated with EBRT alone versus combined EBRT and HDRBT, there was no significant difference in the QoL scores at one year post-treatment

  5. Combination of External Beam Radiotherapy (EBRT) With Intratumoral Injection of Dendritic Cells as Neo-Adjuvant Treatment of High-Risk Soft Tissue Sarcoma Patients

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    Finkelstein, Steven E., E-mail: steven.finkelstein@moffitt.org [H. Lee Moffitt Cancer Center, Tampa, FL (United States); Iclozan, Cristina; Bui, Marilyn M.; Cotter, Matthew J.; Ramakrishnan, Rupal; Ahmed, Jamil; Noyes, David R.; Cheong, David; Gonzalez, Ricardo J.; Heysek, Randy V.; Berman, Claudia; Lenox, Brianna C.; Janssen, William; Zager, Jonathan S.; Sondak, Vernon K.; Letson, G. Douglas; Antonia, Scott J. [H. Lee Moffitt Cancer Center, Tampa, FL (United States); Gabrilovich, Dmitry I., E-mail: dmitry.gabrilovich@moffitt.org [H. Lee Moffitt Cancer Center, Tampa, FL (United States)

    2012-02-01

    Purpose: The goal of this study was to determine the effect of combination of intratumoral administration of dendritic cells (DC) and fractionated external beam radiation (EBRT) on tumor-specific immune responses in patients with soft-tissue sarcoma (STS). Methods and Material: Seventeen patients with large (>5 cm) high-grade STS were enrolled in the study. They were treated in the neoadjuvant setting with 5,040 cGy of EBRT, split into 28 fractions and delivered 5 days per week, combined with intratumoral injection of 10{sup 7} DCs followed by complete resection. DCs were injected on the second, third, and fourth Friday of the treatment cycle. Clinical evaluation and immunological assessments were performed. Results: The treatment was well tolerated. No patient had tumor-specific immune responses before combined EBRT/DC therapy; 9 patients (52.9%) developed tumor-specific immune responses, which lasted from 11 to 42 weeks. Twelve of 17 patients (70.6%) were progression free after 1 year. Treatment caused a dramatic accumulation of T cells in the tumor. The presence of CD4{sup +} T cells in the tumor positively correlated with tumor-specific immune responses that developed following combined therapy. Accumulation of myeloid-derived suppressor cells but not regulatory T cells negatively correlated with the development of tumor-specific immune responses. Experiments with {sup 111}In labeled DCs demonstrated that these antigen presenting cells need at least 48 h to start migrating from tumor site. Conclusions: Combination of intratumoral DC administration with EBRT was safe and resulted in induction of antitumor immune responses. This suggests that this therapy is promising and needs further testing in clinical trials design to assess clinical efficacy.

  6. Salvage brachytherapy for locally recurrent prostate cancer after external beam radiotherapy

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    Yasuhiro Yamada; Koji Okihara; Tsuyoshi Iwata; Koji Masui; Kazumi Kamoi; Kei Yamada; Tsuneharu Miki

    2015-01-01

    External beam radiotherapy (EBRT) is a standard treatment for prostate cancer. Despite the development of novel radiotherapy techniques such as intensity-modulated conformal radiotherapy, the risk of local recurrence after EBRT has not been obviated. Various local treatment options (including salvage prostatectomy, brachytherapy, cryotherapy, and high-intensity focused ultrasound [HIFU]) have been employed in cases of local recurrence after primary EBRT. Brachytherapy is the first-line treatm...

  7. Radical radiotherapy treatment (EBRT + HDR-ICRT of carcinoma of the uterine cervix: Outcome in patients treated at a rural center in India

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    Jain Vandana

    2007-01-01

    Full Text Available Aim: To report the outcome of carcinoma of the uterine cervix patients treated radically by external beam radiotherapy (EBRT and high-dose-rate (HDR intracavitary radiotherapy (ICRT. Materials and Methods: Between January 1997 to December 2001, a total of 550 newly diagnosed cases of carcinoma of the uterine cervix were reported in the department. All cases were staged according to the International Federation of Gynecologists and Oncologists (FIGO staging system, but for analytical convenience, the staging was limited to stages I, II, III, and IV. Out of the 550 cases, 214 completed radical radiotherapy (EBRT + HDR-ICRT and were retrospectively analyzed for presence of local residual disease, local recurrence, distant metastases, radiation reactions, and disease-free survival. Results: There were 7 (3.27%, 88 (41.1%, 101 (47.1%, and 18 (8.4% patients in stage I, II, III, and IV, respectively. The median follow-up time for all patients was 43 months (range: 3-93 months and for patients who were disease free till the last follow-up it was 59 months (range: 24-93 months. The overall treatment time (OTT ranged from 52 to 73 days (median 61 days. The 5-year disease-free mean survival rate was 58%, 44%, 33%, and 15%, with 95% confidence interval of 48 to 68, 37 to 51, 24 to 35, and 6 to 24 for stages I, II, III, and IV, respectively. There were 62 (28.97% cases with local residual disease, 35 (16.3% developed local recurrence/distant metastases, 17 (7.9% developed distant metastases, and 9 (4.2% had local recurrence as well. Discussion and Conclusion: The overall outcome was poor in advanced stage disease, but might be improved by increasing the total dose, decreasing overall duration of treatment, and by adding chemotherapy in patients with disease limited to the pelvis.

  8. Localized External Beam Radiation Therapy (EBRT) to the Pelvis Induces Systemic IL-1Beta and TNF-Alpha Production: Role of the TNF-Alpha Signaling in EBRT-Induced Fatigue.

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    McDonald, Tasha L; Hung, Arthur Y; Thomas, Charles R; Wood, Lisa J

    2016-01-01

    Prostate cancer patients undergoing localized external beam radiation therapy (EBRT) can experience a progressive increase in fatigue, which can affect physical functioning and quality of life. The purpose of this study was to develop a mouse EBRT prostate cancer treatment model with which to determine the role of pro-inflammatory cytokines in the genesis of EBRT-related fatigue. We assessed voluntary wheel-running activity (VWRA) as a proxy for fatigue, food intake and body weight in male C57BL/6 mice undergoing EBRT to the pelvis. In the first experiment, anesthetized male C57BL/6 mice underwent fractionated EBRT to the pelvis for a total dose of 68.2 Gy, thereby mimicking a clinically relevant therapeutic dose and frequency. The day after the last treatment, levels of IL-1β and TNF-α in plasma along with mRNA levels in liver, colon and whole brain were measured. EBRT-induced fatigue resulted in reduced body weight, diminished food intake, and increased plasma and tissue levels of IL-1β and TNF-α. In a follow-up experiment, we used TNF-α-deficient mice to further delineate the role of TNF-α signaling in EBRT-induced sickness behavior. EBRT-induced changes in fatigue, food intake and body weight were no different between TNF-α deficient mice and their wild-type counterparts. Taken together our data demonstrate that a clinically relevant localized irradiation of the pelvis induces a systemic IL-1β and TNF-α response and sickness behavior in mice, but the TNF-α signaling pathway alone does not independently mediate these effects. PMID:26720802

  9. Salvage brachytherapy for locally recurrent prostate cancer after external beam radiotherapy

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    Yasuhiro Yamada

    2015-01-01

    Full Text Available External beam radiotherapy (EBRT is a standard treatment for prostate cancer. Despite the development of novel radiotherapy techniques such as intensity-modulated conformal radiotherapy, the risk of local recurrence after EBRT has not been obviated. Various local treatment options (including salvage prostatectomy, brachytherapy, cryotherapy, and high-intensity focused ultrasound [HIFU] have been employed in cases of local recurrence after primary EBRT. Brachytherapy is the first-line treatment for low-risk and selected intermediate-risk prostate tumors. However, few studies have examined the use of brachytherapy to treat post-EBRT recurrent prostate cancer. The purpose of this paper is to analyze the current state of our knowledge about the effects of salvage brachytherapy in patients who develop locally recurrent prostate cancer after primary EBRT. This article also introduces our novel permanent brachytherapy salvage method.

  10. Salvage brachytherapy for locally recurrent prostate cancer after external beam radiotherapy.

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    Yamada, Yasuhiro; Okihara, Koji; Iwata, Tsuyoshi; Masui, Koji; Kamoi, Kazumi; Yamada, Kei; Miki, Tsuneharu

    2015-01-01

    External beam radiotherapy (EBRT) is a standard treatment for prostate cancer. Despite the development of novel radiotherapy techniques such as intensity-modulated conformal radiotherapy, the risk of local recurrence after EBRT has not been obviated. Various local treatment options (including salvage prostatectomy, brachytherapy, cryotherapy, and high-intensity focused ultrasound [HIFU]) have been employed in cases of local recurrence after primary EBRT. Brachytherapy is the first-line treatment for low-risk and selected intermediate-risk prostate tumors. However, few studies have examined the use of brachytherapy to treat post-EBRT recurrent prostate cancer. The purpose of this paper is to analyze the current state of our knowledge about the effects of salvage brachytherapy in patients who develop locally recurrent prostate cancer after primary EBRT. This article also introduces our novel permanent brachytherapy salvage method. PMID:26112477

  11. Evaluation of the Curative Effect of External Beam Radiotherapy and Brachytherapy for Tongue Carcinoma

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    Ping Wang; Qingsong Pang

    2007-01-01

    OBJECTIVE To evaluate the curative effect of external beam radiotherapy (EBRT) and brachytherapy (BT) for tongue carcinoma. METHODS From 1991 to 2003, 35 patients received EBRT and BT in our department. We analyzed their curative and side effects retrospectively. RESULTS Local control was 80%. The 3-year overall (OS) and disease specific survival (DSS) rates were 75% and 79%. One patient developed metastases. Three patients (9%) developed different late complications. CONCLUSIONS Local regional control, survival, and complications in patients with tongue carcinoma treated by EBRT and BT have been satisfactory.

  12. Single fraction radiotherapy versus multiple fraction radiotherapy for bone metastases in prostate cancer patients: comparative effectiveness

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    External beam radiotherapy (EBRT) is an effective treatment for symptomatic bone metastases from a variety of primary malignancies. Previous meta-analyses and systematic reviews have reported on the efficacy of EBRT on bone metastases from multiple primaries. This review is focused on the comparative effectiveness of single fraction radiotherapy versus multiple fraction radiotherapy for bone metastases in prostate cancer patients

  13. Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement

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    Droege, L.H.; Hinsche, T.; Hess, C.F.; Wolff, H.A. [University Hospital of Goettingen, Department of Radiotherapy and Radiation Oncology, Goettingen (Germany); Canis, M. [University of Goettingen, Department of Otorhinolaryngology, Head and Neck Surgery, Goettingen (Germany); Alt-Epping, B. [University of Goettingen, Department of Palliative Medicine, Goettingen (Germany)

    2014-02-15

    Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting. (orig.)

  14. Erectile function following brachytherapy, external beam radiotherapy, or radical prostatectomy in prostate cancer patients

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    For localized prostate cancer, treatment options include external beam radiotherapy (EBRT), radical prostatectomy (RP), and brachytherapy (BT). Erectile dysfunction (ED) is a common side-effect. Our aim was to evaluate penile erectile function (EF) before and after BT, EBRT, or RP using a validated self-administered quality-of-life survey from a prospective registry. Analysis included 478 patients undergoing RP (n = 252), EBRT (n = 91), and BT (n = 135) with at least 1 year of follow-up and EF documented using IIEF-5 scores at baseline, 6 weeks, 6 months, 1 year, and annually thereafter. Differences among treatments were most pronounced among patients with no or mild initial ED (IIEF-5 ≥ 17). Overall, corrected for baseline EF and age, BT was associated with higher IIEF-5 scores than RP (+ 7.8 IIEF-5 score) or EBRT (+ 3.1 IIEF-5 score). EBRT was associated with better IIEF-5 scores than RP (+ 4.7 IIEF-5 score). In patients undergoing EBRT or RP with bilateral nerve sparing (NS), recovery of EF was observed and during follow-up, the differences to BT were not statistically significant. Overall age had a negative impact on EF preservation (corrected for baseline IIEF). In our series, EF was adversely affected by each treatment modality. Considered overall, BT provided the best EF preservation in comparison to EBRT or RP. (orig.)

  15. Nanoparticle-aided external beam radiotherapy leveraging the Čerenkov effect.

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    Ouyang, Zi; Liu, Bo; Yasmin-Karim, Sayeda; Sajo, Erno; Ngwa, Wilfred

    2016-07-01

    This study investigates the feasibility of exploiting the Čerenkov radiation (CR) present during external beam radiotherapy (EBRT) for significant therapeutic gain, using titanium dioxide (titania) nanoparticles (NPs) delivered via newly designed radiotherapy biomaterials. Using Monte Carlo radiation transport simulations, we calculated the total CR yield inside a tumor volume during EBRT compared to that of the radionuclides. We also considered a novel approach for intratumoral titania delivery using radiotherapy biomaterials (e.g. fiducials) loaded with NPs. The intratumoral distribution/diffusion of titania released from the fiducials was calculated. To confirm the CR induced enhancement in EBRT experimentally, we used 6MV radiation to irradiate human lung cancer cells with or without titania NPs and performed clonogenic assays. For a radiotherapy biomaterial loaded with 20μg/g of 2-nm titania NPs, at least 1μg/g could be delivered throughout a tumor sub-volume of 2-cm diameter after 14days. This concentration level could inflict substantial damage to cancer cells during EBRT. The Monte Carlo results showed the CR yield by 6MV radiation was higher than by the radionuclides of interest and hence greater damage might be obtained during EBRT. In vitro study showed significant enhancement with 6MV radiation and titania NPs. These preliminary findings demonstrate a potential new approach that can be used to take advantage of the CR present during megavoltage EBRT to boost damage to cancer cells. The results provide significant impetus for further experimental studies towards the development of nanoparticle-aided EBRT powered by the Čerenkov effect. PMID:27397906

  16. Nanoparticle-aided external beam radiotherapy leveraging the Čerenkov effect

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    Ouyang, Zi; Liu, Bo; Yasmin-Karim, Sayeda; Sajo, Erno; Ngwa, Wilfred

    2016-01-01

    This study investigates the feasibility of exploiting the Čerenkov radiation (CR) present during external beam radiotherapy (EBRT) for significant therapeutic gain, using titanium dioxide (titania) nanoparticles (NPs) delivered via newly designed radiotherapy biomaterials. Using Monte Carlo radiation transport simulations, we calculated the total CR yield inside a tumor volume during EBRT compared to that of the radionuclides. We also considered a novel approach for intratumoral titania delivery using radiotherapy biomaterials (e.g. fiducials) loaded with NPs. The intratumoral distribution/diffusion of titania released from the fiducials was calculated. To confirm the CR induced enhancement in EBRT experimentally, we used 6 MV radiation to irradiate human lung cancer cells with or without titania NPs and performed clonogenic assays. For a radiotherapy biomaterial loaded with 20 μg/g of 2-nm titania NPs, at least 1 μg/g could be delivered throughout a tumor sub-volume of 2-cm diameter after 14 days. This concentration level could inflict substantial damage to cancer cells during EBRT. The Monte Carlo results showed the CR yield by 6 MV radiation was higher than by the radionuclides of interest and hence greater damage may be obtained during EBRT. In vitro study showed significant enhancement with 6 MV radiation and titania NPs. These preliminary findings demonstrate a potential new approach that can be used to take advantage of the CR present during megavoltage EBRT to boost damage to cancer cells. The results provide significant impetus for further experimental studies towards the development of nanoparticle-aided EBRT powered by the Čerenkov effect. PMID:27397906

  17. Radical prostatectomy versus external beam radiotherapy for localized prostate cancer. Comparison of treatment outcomes

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    Kim, Yeon-Joo; Cho, Kwan Ho; Lee, Kang Hyun; Moon, Sung Ho; Kim, Tae Hyun; Shin, Kyung Hwan; Kim, Joo-Young; Kim, Young-kyung; Lee, Se Byeong [National Cancer Center, Research Institute and Hospital, Goyang (Korea, Republic of); Pyo, Hong Ryull [Sungkyunkwan University, Department of Radiation Oncology, Samsung Medical Center, School of Medicine, Seoul (Korea, Republic of)

    2015-04-01

    We retrospectively compared the treatment outcomes of localized prostate cancer between radical prostatectomy (RP) and external beam radiotherapy (EBRT). We retrospectively analyzed 738 patients with localized prostate cancer who underwent either RP (n = 549) or EBRT (n = 189) with curative intent at our institution between March 2001 and December 2011. Biochemical failure was defined as a prostate-specific antigen (PSA) level of ≥ 0.2 ng/ml in the RP group and the nadir of + ≥ 2 ng/ml in the EBRT group. The median (range) follow-up duration was 48.8 months (0.7-133.2 months) and 48.7 months (1.0-134.8 months) and the median age was 66 years (45-89 years) and 71 years (51-84 years; p < 0.001) in the RP and EBRT groups, respectively. Overall, 21, 42, and 36 % of patients in the RP group, and 15, 27, and 58 % of patients in the EBRT group were classified as low, intermediate, and high risk, respectively (p < 0.001). Androgen-deprivation therapy was more common in the EBRT group (59 vs. 27 %, respectively; p < 0.001). The 8-year biochemical failure-free survival rates were 44 and 72 % (p < 0.001) and the disease-specific survival rates were 98 % and 97 % (p = 0.543) in the RP and EBRT groups, respectively. Although the EBRT group included more high-risk patients than did the RP group, the outcomes of EBRT were not inferior to those of RP. Our data suggest that EBRT is a viable alternative to RP for treating localized prostate cancer. (orig.) [German] Wir vergleichen retrospektiv die Verfahrensergebnisse des lokal begrenzten Prostatakarzinoms zwischen radikaler Prostatektomie (RP) und externer Strahlentherapie (EBRT). Wir analysieren zurueckblickend 738 Patienten mit lokal begrenztem Prostatakarzinom, die zwischen Maerz 2001 und Dezember 2011 in unserem Institut entweder eine RP (n = 549) oder eine EBRT (n = 189) mit kurativer Intention durchliefen. Biochemischer Fehler wurde als prostataspezifisches Antigen (PSA) ≥ 0,2 ng/ml in der RP-Gruppe und ein Nadir +

  18. Neoadjuvant hormonal therapy and external-beam radiotherapy versus external-beam irradiation alone for prostate cancer. A quality-of-life analysis

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    Pinkawa, Michael; Piroth, Marc D.; Asadpour, Branka; Gagel, Bernd; Fischedick, Karin; Siluschek, Jaroslav; Kehl, Mareike; Krenkel, Barbara; Eble, Michael J. [RWTH Aachen (Germany). Dept. of Radiotherapy

    2009-02-15

    To evaluate the impact of neoadjuvant hormonal therapy (NHT) on quality of life after external-beam radiotherapy (EBRT) for prostate cancer. A group of 170 patients (85 with and 85 without NHT) has been surveyed prospectively before EBRT (70.2-72 Gy), at the last day of EBRT, a median time of 2 months and 15 months after EBRT using a validated questionnaire (Expanded Prostate Cancer Index Composite). Pairs with and without NHT (median treatment time of 3.5 months before EBRT) were matched according to the respective planning target volume and prostate volume. Before EBRT, significantly lower urinary function/bother, sexual function and hormonal function/bother scores were found for patients with NHT. More than 1 year after EBRT, only sexual function scores remained lower. In a multivariate analysis, NHT and adjuvant hormonal therapy (HT) versus NHT only (hazard ratio 14; 95% confidence interval 2.7-183; p = 0.02) and luteinizing hormone-releasing hormone (LHRH) agonists versus antiandrogens (hazard ratio 3.6; 95% confidence interval 1.1-12; p = 0.04) proved to be independent risk factors for long-term erectile dysfunction (no or very poor ability to have an erection). With the exception of sexual function (additional adjuvant HT and application of LHRH analog independently adverse), short-term NHT was not found to decrease quality of life after EBRT for prostate cancer. (orig.)

  19. [Prostate cancer external beam radiotherapy].

    Science.gov (United States)

    de Crevoisier, R; Pommier, P; Latorzeff, I; Chapet, O; Chauvet, B; Hennequin, C

    2016-09-01

    The prostate external beam radiotherapy techniques are described, when irradiating the prostate or after prostatectomy, with and without pelvic lymph nodes. The following parts are presented: indications of radiotherapy, total dose and fractionation, planning CT image acquisition, volume of interest delineation (target volumes and organs at risk) and margins, Intensity modulated radiotherapy planning and corresponding dose-volume constraints, and finally Image guided radiotherapy. PMID:27516051

  20. Unified registration framework for cumulative dose assessment in cervical cancer across external beam radiotherapy and brachytherapy

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    Roy, Sharmili; Totman, John J.; Choo, Bok A.

    2016-03-01

    Dose accumulation across External Beam Radiotherapy (EBRT) and Brachytherapy (BT) treatment fractions in cervical cancer is extremely challenging due to structural dissimilarities and large inter-fractional anatomic deformations between the EBRT and BT images. The brachytherapy applicator and the bladder balloon, present only in the BT images, introduce missing structural correspondences for the underlying registration problem. Complex anatomical deformations caused by the applicator and the balloon, different rectum and bladder filling and tumor shrinkage compound the registration difficulties. Conventional free-form registration methods struggle to handle such topological differences. In this paper, we propose a registration pipeline that first transforms the original images to their distance maps based on segmentations of critical organs and then performs non-linear registration of the distance maps. The resulting dense deformation field is then used to transform the original anatomical image. The registration accuracy is evaluated on 27 image pairs from stage 2B-4A cervical cancer patients. The algorithm reaches a Hausdorff distance of close to 0:5 mm for the uterus, 2:2 mm for the bladder and 1:7 mm for the rectum when applied to (EBRT,BT) pairs, taken at time points more than three months apart. This generalized model-free framework can be used to register any combination of EBRT and BT images as opposed to methods in the literature that are tuned for either only (BT,BT) pair, or only (EBRT,EBRT) pair or only (BT,EBRT) pair. A unified framework for 3D dose accumulation across multiple EBRT and BT fractions is proposed to facilitate adaptive personalized radiation therapy.

  1. Palliative treatment of Erdheim-Chester disease with radiotherapy: A Rare Cancer Network study

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    A retrospective study of the use of palliative external beam radiotherapy (EBRT) in nine patients with Erdheim-Chester disease was conducted through the Rare Cancer Network. Patients received EBRT for bone pain, brain infiltration, or retro-orbital involvement. EBRT typically provided short-term palliation, with later recurrence of symptoms in most cases

  2. Erectile function following brachytherapy, external beam radiotherapy, or radical prostatectomy in prostate cancer patients

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    Putora, P.M.; Buchauer, K.; Plasswilm, L. [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland); Engeler, D.; Schmid, H.P. [Kantonsspital St. Gallen, Department of Urology, St. Gallen (Switzerland); Haile, S.R.; Graf, N. [Kantonsspital St. Gallen, Clinical Trials Unit, St. Gallen (Switzerland)

    2016-03-15

    For localized prostate cancer, treatment options include external beam radiotherapy (EBRT), radical prostatectomy (RP), and brachytherapy (BT). Erectile dysfunction (ED) is a common side-effect. Our aim was to evaluate penile erectile function (EF) before and after BT, EBRT, or RP using a validated self-administered quality-of-life survey from a prospective registry. Analysis included 478 patients undergoing RP (n = 252), EBRT (n = 91), and BT (n = 135) with at least 1 year of follow-up and EF documented using IIEF-5 scores at baseline, 6 weeks, 6 months, 1 year, and annually thereafter. Differences among treatments were most pronounced among patients with no or mild initial ED (IIEF-5 ≥ 17). Overall, corrected for baseline EF and age, BT was associated with higher IIEF-5 scores than RP (+ 7.8 IIEF-5 score) or EBRT (+ 3.1 IIEF-5 score). EBRT was associated with better IIEF-5 scores than RP (+ 4.7 IIEF-5 score). In patients undergoing EBRT or RP with bilateral nerve sparing (NS), recovery of EF was observed and during follow-up, the differences to BT were not statistically significant. Overall age had a negative impact on EF preservation (corrected for baseline IIEF). In our series, EF was adversely affected by each treatment modality. Considered overall, BT provided the best EF preservation in comparison to EBRT or RP. (orig.) [German] Die externe Radiotherapie (EBRT), die radikale Prostatektomie (RP) sowie die Brachytherapie (BT) stellen Behandlungsoptionen fuer das lokalisierte Prostatakarzinom dar. Die erektile Dysfunktion (ED) ist eine haeufige Nebenwirkung dieser Therapien. Unser Ziel war es, die penile erektile Funktion (EF) vor und nach BT, EBRT und RP mit Hilfe eines validierten, vom Patienten ausgefuellten Lebensqualitaetsfragebogens aus einer prospektiven Datenbank zu beurteilen. Mit einer minimalen Nachbeobachtungszeit von einem Jahr wurden 478 Patienten analysiert, die eine RP (n = 252), EBRT (n = 91) oder BT (n = 135) erhalten hatten und deren EF mit

  3. Combined effects of MPA and EBRT in stage Ic endometrial cancer patients%Ic期子宫内膜癌患者中MPA和EBRT的联合疗效

    Institute of Scientific and Technical Information of China (English)

    Rumana Jafarey; Wei Zhang; Sun Jing

    2008-01-01

    Objective: To report the comparative effect of combined medroxyprogesterone acetate (MPA) and external beam pelvic radiotherapy (EBRT) with EBRT alone on local or distant recurrences, overall survival and treatment related toxicities in patients with stage Ic grade 3 endometrial cancer. Methods:A retrospective review of 80 International Federation of Gynecology and Obstetrics (FIGO) stage Ic grade 3 endometrial carcinoma patients treated between October 1994 and October 2004 at Renmin Hospital, Wuhan University, China was performed. All patients underwent surgery, of which 40 patients in arm Ⅰ received combined MPA and EBRT while in arm Ⅱ 40 patients received only adjuvant EBRT after surgery. The median dose of EBRT in arm Ⅰ was 50 Gy (range 36-54 Gy) and in arm Ⅱ was 45.2 Gy (range 43.2-50.4 Gy). Multivariate analysis was performed for the prognostic factors and Kaplan-Meier method was used for overall survival. Results: Of the 80 eligible patients, 40 in each group could be evaluated. The follow-up times ranged from 4-98 months with a median of 45 months. The overall survival rates at five years were 73% among patients treated with combined MPA and EBRT and 28.2% among patients treated with EBRT alone (P < 0.001). The rate of distant metastasis was significantly higher among patients treated with EBRT alone group than combined MPA and EBRT (55% vs 25%, P = 0.006) while no difference in Ioco regional recurrence rates was observed in both treatment groups. Most of the side effects observed in the combined MPA and EBRT group. Age (P < 0.001) and the presence of progesterone receptors (P = 0.003) were independent significant prognostic factors for overall survival in multiple regression analysis. Conclusion: We has been concluded that the addition of progestagen to external beam pelvic radiotherapy significantly improved survival and reduced distant metastasis among women with stage Ic grade 3 endometrial cancer.

  4. Hypofractionated SBRT versus conventionally fractionated EBRT for prostate cancer: comparison of PSA slope and nadir

    International Nuclear Information System (INIS)

    Patients with early stage prostate cancer have a variety of curative radiotherapy options, including conventionally-fractionated external beam radiotherapy (CF-EBRT) and hypofractionated stereotactic body radiotherapy (SBRT). Although results of CF-EBRT are well known, the use of SBRT for prostate cancer is a more recent development, and long-term follow-up is not yet available. However, rapid post-treatment PSA decline and low PSA nadir have been linked to improved clinical outcomes. The purpose of this study was to compare the PSA kinetics between CF-EBRT and SBRT in newly diagnosed localized prostate cancer. 75 patients with low to low-intermediate risk prostate cancer (T1-T2; GS 3 + 3, PSA < 20 or 3 + 4, PSA < 15) treated without hormones with CF-EBRT (>70.2 Gy, <76 Gy) to the prostate only, were identified from a prospectively collected cohort of patients treated at the University of California, San Francisco (1997–2012). Patients were excluded if they failed therapy by the Phoenix definition or had less than 1 year of follow-up or <3 PSAs. 43 patients who were treated with SBRT to the prostate to 38 Gy in 4 daily fractions also met the same criteria. PSA nadir and rate of change in PSA over time (slope) were calculated from the completion of RT to 1, 2 and 3 years post-RT. The median PSA nadir and slope for CF-EBRT was 1.00, 0.72 and 0.60 ng/ml and -0.09, -0.04, -0.02 ng/ml/month, respectively, for durations of 1, 2 and 3 years post RT. Similarly, for SBRT, the median PSA nadirs and slopes were 0.70, 0.40, 0.24 ng and -0.09, -0.06, -0.05 ng/ml/month, respectively. The PSA slope for SBRT was greater than CF-EBRT (p < 0.05) at 2 and 3 years following RT, although similar during the first year. Similarly, PSA nadir was significantly lower for SBRT when compared to EBRT for years 2 and 3 (p < 0.005). Patients treated with SBRT experienced a lower PSA nadir and greater rate of decline in PSA 2 and 3 years following completion of RT than with CF-EBRT, consistent

  5. Development of late toxicity and International Prostate Symptom Score resolution after external-beam radiotherapy combined with pulsed dose rate brachytherapy for prostate cancer

    NARCIS (Netherlands)

    B.R. Pieters; E. Rezaie; E.D. Geijsen; K. Koedooder; J.N.B. van der Grient; L.E.C.M. Blank; T.M. de Reijke; C.C.E. Koning

    2011-01-01

    To investigate the development of gastrointestinal (GI) toxicity, genitourinary (GU) toxicity, erectile dysfunction, and International Prostate Symptom Score (IPSS) resolution in a cohort of patients treated with external-beam radiotherapy (EBRT) followed by a brachytherapy pulsed dose rate (PDR) bo

  6. Planning of External Beam Radiotherapy for Prostate Cancer Guided by PET/CT.

    Science.gov (United States)

    von Eyben, Finn Edler; Kairemo, Kalevi; Kiljunen, Timo; Joensuu, Timo

    2015-01-01

    In this paper, we give an overview of articles on non-choline tracers for PET/CT for patients with prostate cancer and planning of radiotherapy guided by PET/CT. Nineteen articles described (11)C-Acetate PET/CT. Of 629 patients 483 (77%, 95% CI 74% - 80%) had positive (11)C-Acetate PET/CT scans. Five articles described (18)F-FACBC PET/CT. Of 174 patients, 127 (73%, 95% CI 68% - 78%) had positive scans. Both tracers detected local lesions, lesions in regional lymph nodes, and distant organs. Ten articles described (18)F-NaF PET/CT and found that 1289 of 3918 patients (33%) had positive reactive lesions in bones. PET/CT scan can guide external beam radiotherapy (EBRT) planning for patients with loco-regional prostate cancer. In six studies with 178 patients with localized prostate cancer, PET/CT pointed out dominant intraprostatic lesions (DIL). Oncologists gave EBRT to the whole prostate and a simultaneously integrated boost to the DIL. Four studies with 254 patients described planning of EBRT for patients with PETpositive lymph nodes. After the EBRT, 15 of 29 node-positive patients remained in remission for median 28 months (range 14 to 50 months). Most articles describe (11)C- and (18)F-Choline PET/CT. However, (11)C-Acetate and (18)F-FACBC may also be useful tracers for PET/CT. Planning of radiotherapy guided by MRI or PET/CT is an investigational method for localized prostate cancer. Current clinical controlled trials evaluate whether the method improves overall survival.

  7. Role of adjuvant postoperative external beam radiotherapy for well differentiated thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jeanny; Wu, Hong Gyun; Youn, Yeo Kyu; Lee, Kyu Eun; Kim, Kwang Hyun; Park, Do Joon [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2013-09-15

    To analyze the outcome of adjuvant postoperative external beam radiotherapy (EBRT) in well-differentiated thyroid cancer (WDTC). We identified 84 patients treated with EBRT for WDTC from February 1981 to December 2010. Among them, we analyzed 39 patients who received EBRT after initial radical surgery. Twenty-four females and 15 males were included. The median age was 49 years (range, 16 to 72 years). There were 34 papillary thyroid carcinomas and 5 follicular thyroid carcinomas. Most patients showed pathologic T3/T4 stage (54%/26%). Ten patients (25.6%) had gross residual tumors. Five patients (12.8%) had tumor cells at the margin. The median EBRT dose and fraction size were 62.6 Gy and 1.8 to 2.0 Gy, respectively. The median follow-up was 73 months (range, 21 to 372 months). The five-year overall survival (OS) and locoregional recurrence free survival (LRFS) were 97.4% and 86.9%, respectively. Locoregional failures occurred in 5 and all failure sites were the neck node area. In univariate analysis, OS was significantly influenced by invasion of the trachea (p = 0.016) or esophagus (p = 0.006). LRFS was significantly decreased by male (p = 0.020), gross residuum after resection (p = 0.002), close or positive tumor at surgical margin involvement (p = 0.044), and tracheal invasion (p = 0.040). No significant prognostic factor was identified in the multivariate analysis. No patient experienced the Radiation Therapy Oncology Group grade 3 or more toxicity. Our locoregional control rate of 87.2% is comparable to historical controls with surgery alone, even though our study had a large proportion of advanced stage. Adjuvant EBRT may an effective and safe treatment option in patients with WDTC.

  8. Risk-adapted targeted intraoperative radiotherapy versus whole-breast radiotherapy for breast cancer

    DEFF Research Database (Denmark)

    Vaidya, Jayant S; Wenz, Frederik; Bulsara, Max;

    2014-01-01

    The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intraoperative radiotherapy (TARGIT) versus fractionated external beam radiotherapy (EBRT) for breast cancer. We report 5-year results for local recurrence and the first analysis of overall survival....

  9. Outcomes of Patients With Non-Hodgkin's Lymphoma Treated With Bexxar With or Without External-Beam Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kristy; Byer, Gracie; Morris, Christopher G.; Kirwan, Jessica M.; Lightsey, Judith [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL (United States); Mendenhall, Nancy P., E-mail: menden@shands.ufl.edu [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL (United States); Hoppe, Bradford S.; Lynch, James [Division of Hematology/Oncology, University of Florida College of Medicine, Gainesville, FL (United States); Olivier, Kenneth [Mayo Clinic, Rochester, MN (United States)

    2012-03-01

    Purpose: To compare the efficacy and toxicity of external-beam radiotherapy (EBRT) to sites of bulky lymphadenopathy in patients with chemotherapy-refractory low-grade non-Hodgkin's lymphoma (NHL) immediately before receiving Bexxar (tositumomab and {sup 131}I) vs. in patients receiving Bexxar alone for nonbulky disease. Methods and Materials: Nineteen patients with chemotherapy-refractory NHL were treated with Bexxar at our institution (University of Florida, Gainesville, FL) from 2005 to 2008. Seventeen patients had Grade 1-2 follicular lymphoma. Ten patients received a median of 20 Gy in 10 fractions to the areas of clinical involvement, immediately followed by Bexxar (EBRT + Bexxar); 9 patients received Bexxar alone. The median tumor sizes before EBRT + Bexxar and Bexxar alone were 4.8 cm and 3.3 cm, respectively. All 5 patients with a tumor diameter >5 cm were treated with EBRT + Bexxar. A univariate analysis of prognostic factors for progression-free survival (PFS) was performed. Results: The median follow-up was 2.3 years for all patients and 3.1 years for 12 patients alive at last follow-up. Of all patients, 79% had a partial or complete response; 4 of the 8 responders in the EBRT + Bexxar group achieved a durable response of over 2 years, including 3 of the 5 with tumors >5 cm. Three of 9 patients treated with Bexxar alone achieved a durable response over 2 years. Actuarial estimates of 3-year overall survival and PFS for EBRT + Bexxar and Bexxar alone were 69% and 38% and 62% and 33%, respectively. The median time to recurrence after EBRT + Bexxar and Bexxar alone was 9 months. Having fewer than 4 involved lymph-node regions was associated with superior PFS at 3 years (63% vs. 18%). There was no Grade 4 or 5 complications. Conclusions: Adding EBRT immediately before Bexxar produced PFS equivalent to that with Bexxar alone, despite bulkier disease. Hematologic toxicity was not worsened. EBRT combined with Bexxar adds a safe and effective therapeutic

  10. Palliative external-beam radiotherapy for bone metastases from hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Shinya; Hayashi; Hidekazu; Tanaka; Hiroaki; Hoshi

    2014-01-01

    The incidence of bone metastases(BMs)from hepatocellular carcinoma(HCC)is relatively low compared to those of other cancers,but it has increased recently,especially in Asian countries.Typically,BMs from HCC appear radiologically as osteolytic,destructive,and expansive components with large,bulky soft-tissue masses.These soft-tissue masses are unique to bone metastases from HCC and often replace the normal bone matrix and exhibit expansive growth.They often compress the peripheral nerves,spinal cord,or cranial nerves,causing not only bone pain but also neuropathic pain and neurological symptoms.In patients with spinal BMs,the consequent metastatic spinal cord compression(MSCC)causes paralysis.Skull base metastases(SBMs)with cranial nerve involvement can cause neurological symptoms.Therefore,patients with bony lesions often suffer from pain or neurological symptoms that have a severe,adverse effect on the quality of life.External-beam radiotherapy(EBRT)can effectively relieve bone pain and neurological symptoms caused by BMs.However,EBRT is not yet widely used for the palliative management of BMs from HCC because of the limited number of relevant studies.Furthermore,the optimal dosing schedule remains unclear,despite clinical evidence to support single-fraction ra-diation schedules for primary cancers.In this review,we outline data describing palliative EBRT for BMs from HCC in the context of(1)bone pain;(2)MSCC;and(3)SBMs.

  11. Radiotherapy for pituitary adenomas: long-term outcome and complications

    OpenAIRE

    Rim, Chai Hong; Yang, Dae Sik; Park, Young Je; Yoon, Won Sup; Lee, Jung Ae; Kim, Chul Yong

    2011-01-01

    Purpose To evaluate long-term local control rate and toxicity in patients treated with external beam radiotherapy (EBRT) for pituitary adenomas. Materials and Methods We retrospectively reviewed the medical records of 60 patients treated with EBRT for pituitary adenoma at Korea University Medical Center from 1996 and 2006. Thirty-five patients had hormone secreting tumors, 25 patients had non-secreting tumors. Fifty-seven patients had received postoperative radiotherapy (RT), and 3 had receiv...

  12. Single fraction radiotherapy versus multiple fraction radiotherapy for bone metastases in prostate cancer patients: comparative effectiveness

    Directory of Open Access Journals (Sweden)

    Yoon F

    2014-11-01

    Full Text Available Frederick Yoon,1 Gerard C Morton2 1Simcoe Muskoka Regional Cancer Centre, Royal Victoria Regional Health Centre, Barrie, ON, Canada; 2Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada Abstract: External beam radiotherapy (EBRT is an effective treatment for symptomatic bone metastases from a variety of primary malignancies. Previous meta-analyses and systematic reviews have reported on the efficacy of EBRT on bone metastases from multiple primaries. This review is focused on the comparative effectiveness of single fraction radiotherapy versus multiple fraction radiotherapy for bone metastases in prostate cancer patients. Keywords: radiotherapy, bone, metastases, prostate, comparative effectiveness

  13. Conservative treatment of a recto-urethral fistula due to savage HIFU for local recurrence of prostate cancer, 5 years after radical prostatectomy and external beam radiotherapy

    OpenAIRE

    Topazio, Luca; Perugia, Claudio; Finazzi-Agro, Enrico

    2012-01-01

    Recto-urethral fistula is one of the most serious complications caused by high-intensity-focused ultrasound used as salvage treatment for recurrence of prostate cancer after brachytherapy or external beam radiotherapy (EBRT). We report the case of a recto-urethral fistula in a 68-year-old patient, who previously had undergone radical prostatectomy and EBRT for prostate cancer (pT3 N0 Mx). The fistula was treated conservatively by an indwelling Foley catheter, without the creation of an intest...

  14. Prostate-specific antigen (PSA) rate of decline post external beam radiotherapy predicts prostate cancer death

    International Nuclear Information System (INIS)

    Background and purpose: To assess the association between PSA velocity (PSAV) in the first 24 months after external beam radiotherapy (EBRT) and prostate cancer-specific mortality (PCSM) and all cause mortality. Materials and methods: All eligible patients in the South Australian (SA) Prostate Cancer Clinical Outcomes registry were followed. 848 Patients treated by definitive EBRT with more than one PSA recorded in the two year post-treatment were included. We calculated PSAV by linear regression. Results: The mean number of PSA measurements in the 2 year period was 4.4 (SD1.9). The median PSAVs across quartiles (Q1–Q4) were −4.17, −1.29, −0.38 and 0.20 ng/ml/yr. In multivariable analysis, a U-shaped relationship was seen between PSAV and PCSM with Q1–Q4 hazard ratios (HR) being 3.82 (1.46–10.00), 3.07 (1.10–8.58), 1, 5.15 (1.99–13.30) respectively. HR for all cause mortality in a similar model were 1.79 (1.07–2.98), 1.55 (0.93–2.59), 1.00 and 1.74 (1.04–2.90) for Q1 to Q4 respectively. A rapid PSA decline in the first year was a strong predictor of PCSM. However, in the second year PSA increase was positively associated with PCSM. Conclusion: A rapid decline in PSA in the first year following EBRT is positively associated with PCSM. This may be a useful early indicator of the need for additional therapies

  15. Variation in Use of Androgen Suppression With External-Beam Radiotherapy for Nonmetastatic Prostate Cancer

    International Nuclear Information System (INIS)

    Purpose: To describe practice patterns associated with androgen suppression (AS) stratified by disease risk group in patients undergoing external-beam radiotherapy (EBRT) for localized prostate cancer. Methods and Materials: We identified 2,184 low-risk, 2,339 intermediate-risk, and 2,897 high-risk patients undergoing EBRT for nonmetastatic prostate cancer diagnosed between January 1, 2004, and December 31, 2005, in the linked Surveillance, Epidemiology, and End Results—Medicare database. We examined the association of patient, clinical, and demographic characteristics with AS use by multivariate logistic regression. Results: The proportions of patients receiving AS for low-risk, intermediate-risk, and high-risk prostate cancer were 32.2%, 56.3%, and 81.5%, respectively. AS use among men in the low-risk disease category varied widely, ranging from 13.6% in Detroit to 47.8% in Kentucky. We observed a significant decline in AS use between 2004 and 2005 within all three disease risk categories. Men aged ≥75 years or with elevated comorbidity levels were more likely to receive AS. Conclusion: Our results identified apparent overuse and underuse of AS among men within the low-risk and high-risk disease categories, respectively. These results highlight the need for clinician and patient education regarding the appropriate use of AS. Practice patterns among intermediate-risk patients reflect the clinical heterogeneity of this population and underscore the need for better evidence to guide the treatment of these patients.

  16. Variation in Use of Androgen Suppression With External-Beam Radiotherapy for Nonmetastatic Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Swisher-McClure, Samuel, E-mail: Swisher-Mcclure@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Pollack, Craig E. [Division of General Internal Medicine, Johns Hopkins University School of Medicine and Johns Hopkins Bloomberg School of Public Health, Baltimore, MD (United States); Christodouleas, John P. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Guzzo, Thomas J. [Department of Surgery, Division of Urology, University of Pennsylvania, Philadelphia, PA (United States); Haas, Naomi B. [Department of Medicine, Division of Hematology and Oncology, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Vapiwala, Neha [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Bekelman, Justin E. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Abramson Cancer Center, University of Pennsylvania, Philadelphia, PA (United States); Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA (United States)

    2012-05-01

    Purpose: To describe practice patterns associated with androgen suppression (AS) stratified by disease risk group in patients undergoing external-beam radiotherapy (EBRT) for localized prostate cancer. Methods and Materials: We identified 2,184 low-risk, 2,339 intermediate-risk, and 2,897 high-risk patients undergoing EBRT for nonmetastatic prostate cancer diagnosed between January 1, 2004, and December 31, 2005, in the linked Surveillance, Epidemiology, and End Results-Medicare database. We examined the association of patient, clinical, and demographic characteristics with AS use by multivariate logistic regression. Results: The proportions of patients receiving AS for low-risk, intermediate-risk, and high-risk prostate cancer were 32.2%, 56.3%, and 81.5%, respectively. AS use among men in the low-risk disease category varied widely, ranging from 13.6% in Detroit to 47.8% in Kentucky. We observed a significant decline in AS use between 2004 and 2005 within all three disease risk categories. Men aged {>=}75 years or with elevated comorbidity levels were more likely to receive AS. Conclusion: Our results identified apparent overuse and underuse of AS among men within the low-risk and high-risk disease categories, respectively. These results highlight the need for clinician and patient education regarding the appropriate use of AS. Practice patterns among intermediate-risk patients reflect the clinical heterogeneity of this population and underscore the need for better evidence to guide the treatment of these patients.

  17. Minimal requirements for quality controls in radiotherapy with external beams

    International Nuclear Information System (INIS)

    Physical dosimetric guidelines have been developed by the Italian National Institute of Health study group on quality assurance in radiotherapy to define protocols for quality controls in external beam radiotherapy. While the document does not determine strict rules or firm recommendations, it suggests minimal requirements for quality controls necessary to guarantee an adequate degree of accuracy in external beam radiotherapy

  18. External and intraoperative radiotherapy for resectable and unresectable pancreatic cancer: analysis of survival rates and complications

    International Nuclear Information System (INIS)

    Purpose: Clinical results of intraoperative radiotherapy (IORT) and/or external beam radiotherapy (EBRT) for both resectable and unresectable pancreatic cancer were analyzed. Methods and Materials: Between 1980 and 1995, 332 patients with pancreatic cancer were treated with surgery and/or radiation therapy (RT). Of the 332 patients, 157 patients were treated with surgical resection of pancreatic tumor, and the remaining 175 patients had unresectable pancreatic tumors. Among the 157 patients with resected pancreatic cancer, 62 patients were not treated with RT, while 40 patients were treated with EBRT alone (mean RT dose; 46.3 Gy) and 55 patients with IORT (25.2 Gy) ± EBRT (44.0 Gy). On the other hand, among the 175 patients with unresectable pancreatic cancer, 58 patients were not treated with RT, 46 patients were treated with EBRT alone (39.2 Gy), and the remaining 71 patients with IORT (29.3 Gy) ± EBRT (41.2 Gy). Results: For 87 patients with curative resection, the median survival times (MSTs) of the no-RT, the EBRT, and the IORT ± EBRT groups were 10.4, 13.0, and 15.5 months, respectively, without significant difference. For 70 patients with non curative resection, the MSTs of the no-RT, the EBRT, and the IORT ± EBRT groups were 5.3, 8.7, and 6.5 months, respectively. When the EBRT and the IORT ± EBRT groups were combined, the survival rate was significantly higher than that of the no RT group for non curatively resected pancreatic cancers (log rank test; p = 0.028). The 2-year survival probability of the IORT ± EBRT group (16%) was higher than that of the EBRT group (0%). For unresectable pancreatic cancer, the MSTs of 52 patients without distant metastases were 6.7 months for palliative surgery alone, 7.6 months for EBRT alone, and 8.2 months for IORT ± EBRT. The survival curve of the IORT ± EBRT group was significantly better than that of the no-RT group (p 2 years) were obtained by IORT ± EBRT for non curatively resected and unresectable pancreatic

  19. Monitor tables for electron beams in radiotherapy

    International Nuclear Information System (INIS)

    The application of electron beams in radiotherapy is still based on tables of monitor units, although 3-D treatment planning systems for electron beams are available. This have several reasons: The need for 3-D treatment planning is not recognized; there is no confidence in the calculation algorithm; Monte-Carlo algorithms are too time-consuming; and the effort necessary to measure basic beam data for 3-D planning is considered disproportionate. However, the increasing clinical need for higher dosimetric precision and for more conformal electron beams leads to the requirement for more sophisticated tables of monitor units. The present paper summarizes and discusses the main aspects concerning the preparation of tables of monitor units for electron beams. The measurement equipment and procedures for measuring basic beam data needed for tables of monitor units for electron beams are described for a standard radiation therapy linac. The design of tables of monitor units for standard electron applicators is presented; this design can be extended for individual electron inserts, to variable applicator surface distances, to oblique beam incidence, and the use of bolus material. Typical data of an Elekta linac are presented in various tables. (orig.)

  20. Stereotactic Body Radiotherapy as Monotherapy or Post-External Beam Radiotherapy Boost for Prostate Cancer: Technique, Early Toxicity, and PSA Response

    Energy Technology Data Exchange (ETDEWEB)

    Jabbari, Siavash [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Weinberg, Vivian K. [Biostatistics and Computational Biology Core, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, California (United States); Kaprealian, Tania; Hsu, I-Chow; Ma Lijun; Chuang, Cynthia; Descovich, Martina; Shiao, Stephen [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Shinohara, Katsuto [Department of Urology, University of California San Francisco, San Francisco, California (United States); Roach, Mack [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States); Department of Urology, University of California San Francisco, San Francisco, California (United States); Gottschalk, Alexander R., E-mail: AGottschalk@radonc.ucsf.edu [Department of Radiation Oncology, University of California San Francisco, San Francisco, California (United States)

    2012-01-01

    Purpose: High dose rate (HDR) brachytherapy has been established as an excellent monotherapy or after external-beam radiotherapy (EBRT) boost treatment for prostate cancer (PCa). Recently, dosimetric studies have demonstrated the potential for achieving similar dosimetry with stereotactic body radiotherapy (SBRT) compared with HDR brachytherapy. Here, we report our technique, PSA nadir, and acute and late toxicity with SBRT as monotherapy and post-EBRT boost for PCa using HDR brachytherapy fractionation. Patients and Methods: To date, 38 patients have been treated with SBRT at University of California-San Francisco with a minimum follow-up of 12 months. Twenty of 38 patients were treated with SBRT monotherapy (9.5 Gy Multiplication-Sign 4 fractions), and 18 were treated with SBRT boost (9.5 Gy Multiplication-Sign 2 fractions) post-EBRT and androgen deprivation therapy. PSA nadir to date for 44 HDR brachytherapy boost patients with disease characteristics similar to the SBRT boost cohort was also analyzed as a descriptive comparison. Results: SBRT was well tolerated. With a median follow-up of 18.3 months (range, 12.6-43.5), 42% and 11% of patients had acute Grade 2 gastrourinary and gastrointestinal toxicity, respectively, with no Grade 3 or higher acute toxicity to date. Two patients experienced late Grade 3 GU toxicity. All patients are without evidence of biochemical or clinical progression to date, and favorably low PSA nadirs have been observed with a current median PSA nadir of 0.35 ng/mL (range, <0.01-2.1) for all patients (0.47 ng/mL, range, 0.2-2.1 for the monotherapy cohort; 0.10 ng/mL, range, 0.01-0.5 for the boost cohort). With a median follow-up of 48.6 months (range, 16.4-87.8), the comparable HDR brachytherapy boost cohort has achieved a median PSA nadir of 0.09 ng/mL (range, 0.0-3.3). Conclusions: Early results with SBRT monotherapy and post-EBRT boost for PCa demonstrate acceptable PSA response and minimal toxicity. PSA nadir with SBRT boost

  1. Preoperative external beam radiotherapy and reduced dose brachytherapy for carcinoma of the cervix: survival and pathological response

    Directory of Open Access Journals (Sweden)

    Pellizzon Antonio

    2007-02-01

    Full Text Available Abstract Purpose To evaluate the pathologic response of cervical carcinoma to external beam radiotherapy (EBRT and high dose rate brachytherapy (HDRB and outcome. Materials and methods Between 1992 and 2001, 67 patients with cervical carcinoma were submitted to preoperative radiotherapy. Sixty-five patients were stage IIb. Preoperative treatment included 45 Gy EBRT and 12 Gy HDRB. Patients were submitted to surgery after a mean time of 82 days. Lymphadenectomy was performed in 81% of patients. Eleven patients with residual cervix residual disease on pathological specimen were submitted to 2 additional insertions of HDRB. Results median follow up was 72 months. Five-year cause specific survival was 75%, overall survival 65%, local control 95%. Complete pelvic pathological response was seen in 40%. Surgery performed later than 80 days was associated with pathological response. Pelvic nodal involvement was found in 12%. Complete pelvic pathological response and negative lymphnodes were associated with better outcome (p = .03 and p = .005. Late grade 3 and 4 urinary and intestinal adverse effects were seen in 12 and 2% of patients. Conclusion Time allowed between RT and surgery correlated with pathological response. Pelvic pathological response was associated with improved outcome. Postoperative additional HDRB did not improve therapeutic results. Treatment was well tolerated.

  2. Intraoperative EBRT and resection for renal cell carcinoma. Twenty-year outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, F.A. [Hospital Gneral Universitario Gregorio Maranon, Madrid (Spain). Dept. of Oncology; Complutense Univ., Madrid (Spain). School of Medicine; Sole, C.V. [Hospital Gneral Universitario Gregorio Maranon, Madrid (Spain). Dept. of Oncology; Complutense Univ., Madrid (Spain). School of Medicine; Instituto de Radiomedicina, Santiago (Spain). Service of Radiation Oncology; Martinez-Monge, R.; Aristu, J. [Clinica Universitaria de Navarra, Pamplona (Spain). Dept. of Radiation Oncology; Azinovic, I. [Hospital de San Jaime, Torrevieja (Spain). Dept. of Radiation Oncology; Zudaire, J.; Berian, J.M. [Clinica Universitaria de Navarra, Pamplona (Spain). Dept. of Urology; Garcia-Sabrido, J.L. [Hospital General Universitario Gregorio Maranon, Madrid (Spain). Dept. of General Surgery

    2013-02-15

    Purpose: We report the outcomes of a multimodality treatment approach combining maximal surgical resection and intraoperative electron radiotherapy (IOERT) with or without external beam radiation therapy (EBRT) in patients with locoregionally (LR) recurrent renal cell carcinoma (RCC) after radical nephrectomy or LR advanced primary RCC. Patients and methods: From 1983 to 2008, 25 patients with LR recurrent (n = 10) or LR advanced primary (n = 15) RCC were treated with this approach. Median patient age was 60 years (range, 16-79 years). Fifteen patients (60%) received perioperative EBRT (median dose, 44 Gy). Surgical resection was R0 (negative margins) in 6 patients (24%) and R1 (residual microscopic disease) in 19 patients (76%). The median dose of IOERT was 14 Gy (range, 9-15). Overall survival (OS) and relapse patterns were calculated using the Kaplan-Meier method. Results: Median follow-up for surviving patients was 22.2 years (range, 3.6-26 years). OS and DFS at 5 and 10 years were 38% and 18% and 19% and 14%, respectively. LR control (tumor bed or regional lymph nodes) and distant metastases-free survival rates at 5 years were 80% and 22%, respectively. The death rate within 30 days of surgery and IOERT was 4% (n = 1). Six patients (24%) experienced acute or late toxicities of grade 3 or higher according to the National Cancer Institute Common Toxicity Criteria (NCI-CTCAE) v4. Conclusion: In patients with LR recurrent or LR advanced primary RCC, a multimodality approach consisting of maximal surgical resection and IOERT with or without adjuvant EBRT yielded encouraging local control results, justifying further evaluation. (orig.)

  3. Radical External Beam Radiotherapy for Clinically Localized Prostate Cancer in Japan: Changing Trends in the Patterns of Care Process Survey

    International Nuclear Information System (INIS)

    Purpose: To delineate changing trends in radical external beam radiotherapy (EBRT) for prostate cancer in Japan. Methods and Materials: Data from 841 patients with clinically localized prostate cancer treated with EBRT in the Japanese Patterns of Care Study (PCS) from 1996 to 2005 were analyzed. Results: Significant increases in the proportions of patients with stage T1 to T2 disease and decrease in prostate-specific antigen values were observed. Also, there were significant increases in the percentages of patients treated with radiotherapy by their own choice. Median radiation doses were 65.0 Gy and 68.4 Gy from 1996 to 1998 and from 1999 to 2001, respectively, increasing to 70 Gy from 2003 to 2005. Moreover, conformal therapy was more frequently used from 2003 to 2005 (84.9%) than from 1996 to 1998 (49.1%) and from 1999 to 2001 (50.2%). On the other hand, the percentage of patients receiving hormone therapy from 2003 to 2005 (81.1%) was almost the same as that from 1996 to 1998 (86.3%) and from 1999 to 2001 (89.7%). Compared with the PCS in the United States, patient characteristics and patterns of treatments from 2003 to 2005 have become more similar to those in the United States than those from 1996 to 1998 and those from 1999 to 2001. Conclusions: This study indicates a trend toward increasing numbers of patients with early-stage disease and increasing proportions of patients treated with higher radiation doses with advanced equipment among Japanese prostate cancer patients treated with EBRT during 1996 to 2005 survey periods. Patterns of care for prostate cancer in Japan are becoming more similar to those in the United States.

  4. Combined total body X-ray irradiation and total skin electron beam radiotherapy with an improved technique for mycosis fungoides

    International Nuclear Information System (INIS)

    Twelve consecutive patients with advanced stage mycosis fungoides (MF) were treated with combined total body X ray irradiation (TBI) and total skin electron beam radiotherapy (EBRT). Six had generalized plaque disease and dermatopathic nodes, three had tumor stage disease and node biopsy positive for mycosis fungoides, and three had erythroderma/Sezary syndrome. The treatment regimen consisted of split course total body X ray irradiation, given in twice weekly 15 cGy fractions to 75 cGy, then total skin electron beam radiation therapy given in once weekly 400 cGy fractions to a total dose of 2400 cGy. Underdosed areas and areas of greatest initial involvement were boosted 400 cGy twice weekly for an additional 1200 cGy. This was followed by a second course of total body X ray irradiation, to a total dose of 150 cGy. The total skin electron beam radiotherapy technique is a modification of an established six position EBRT technique for mycosis fungoides. Measurements to characterize the beam with and without a lexan scattering plate, demonstrated that the combination of no-plate beams produced better dose uniformity with a much higher dose rate. This improved technique is particularly advantageous for elderly and/or frail patients. Nine (75%) of the 12 patients achieved complete response (CR). The other three had significant improvement with greater than 80% clearing of their disease and resolution of symptoms. All six patients with generalized plaque disease achieved complete response and remained free of disease from 2 to 16 months. Two of three node positive patients also achieved complete response; one, with massive biopsy-documented mycosis fungoides nodal disease and deep open tumors, remained relapse-free over 2 years. Only one of the three patients with erythroderma/Sezary syndrome achieved a complete response, which was short lived

  5. Combined total body X-ray irradiation and total skin electron beam radiotherapy with an improved technique for mycosis fungoides

    Energy Technology Data Exchange (ETDEWEB)

    Halberg, F.E.; Fu, K.K.; Weaver, K.A.; Zackheim, H.S.; Epstein, E.H. Jr.; Wintroub, B.U.

    1989-08-01

    Twelve consecutive patients with advanced stage mycosis fungoides (MF) were treated with combined total body X ray irradiation (TBI) and total skin electron beam radiotherapy (EBRT). Six had generalized plaque disease and dermatopathic nodes, three had tumor stage disease and node biopsy positive for mycosis fungoides, and three had erythroderma/Sezary syndrome. The treatment regimen consisted of split course total body X ray irradiation, given in twice weekly 15 cGy fractions to 75 cGy, then total skin electron beam radiation therapy given in once weekly 400 cGy fractions to a total dose of 2400 cGy. Underdosed areas and areas of greatest initial involvement were boosted 400 cGy twice weekly for an additional 1200 cGy. This was followed by a second course of total body X ray irradiation, to a total dose of 150 cGy. The total skin electron beam radiotherapy technique is a modification of an established six position EBRT technique for mycosis fungoides. Measurements to characterize the beam with and without a lexan scattering plate, demonstrated that the combination of no-plate beams produced better dose uniformity with a much higher dose rate. This improved technique is particularly advantageous for elderly and/or frail patients. Nine (75%) of the 12 patients achieved complete response (CR). The other three had significant improvement with greater than 80% clearing of their disease and resolution of symptoms. All six patients with generalized plaque disease achieved complete response and remained free of disease from 2 to 16 months. Two of three node positive patients also achieved complete response; one, with massive biopsy-documented mycosis fungoides nodal disease and deep open tumors, remained relapse-free over 2 years. Only one of the three patients with erythroderma/Sezary syndrome achieved a complete response, which was short lived.

  6. External beam radiotherapy for thyroid cancer

    International Nuclear Information System (INIS)

    The indications for and techniques of external beam radiotherapy for thyroid tumours can be clearly defined in relation to the histological type of tumour and stage of disease. Localized treatment for carcinoma can easily be accomplished as can wide field irradiation for lymphoma. However, when either extensive lateral neck disease is present or tumour extends into the superior mediastinum, it becomes difficult to adequately encompass the required volume without including the spinal cord. Several techniques are described which overcome this problem and thus allow a radical dose to be given without significant risk of transverse myelitis

  7. High-Intensity Focused Ultrasound as Salvage Therapy for Patients With Recurrent Prostate Cancer After Radiotherapy

    OpenAIRE

    Song, Wan; Jung, U Seok; Suh, Yoon Seok; Jang, Hyun Jun; Sung, Hyun Hwan; Jeon, Hwang Gyun; Jeong, Byung Chang; Seo, Seong Il; Jeon, Seong Soo; Choi, Han Yong; Lee, Hyun Moo

    2014-01-01

    Purpose To evaluate the oncologic outcomes and postoperative complications of high-intensity focused ultrasound (HIFU) as a salvage therapy after external-beam radiotherapy (EBRT) failure in patients with prostate cancer. Materials and Methods Between February 2002 and August 2010, we retrospectively reviewed the medical records of all patients who underwent salvage HIFU for transrectal ultrasound-guided, biopsy-proven locally recurred prostate cancer after EBRT failure (by ASTRO definition: ...

  8. ILBT BOOST FOLLOWING EBRT IN LOCALLY ADVANCED OESOPHAGEAL CARCINOMA- IS IT REALLY CURATIVE OR JUST PALLIATION?

    Directory of Open Access Journals (Sweden)

    Rajeev

    2016-05-01

    Full Text Available INTRODUCTION Oesophageal Cancer is usually associated with late presentation and poor prognosis. Unfortunately, advanced disease at presentation is seen in around 70% oesophageal cancer patients with limited curative option. The main objective of treatment remains palliation. Different treatment modalities were tried in locally advanced oesophageal cancer, but the median survival remains less than 10 months. [1-3] A combination of these modalities in advanced cases has marginally improved the results. Radiotherapy can be external beam (EBRT alone, intraluminal brachytherapy (ILBT alone or combination of both and nowadays IMRT/IGRT with different fractionation schedules have some promising results and needs further exploration through large clinical studies. MATERIAL AND METHODS We evaluated the efficacy and safety of EBRT followed by ILBT in locally advanced unresectable cases of carcinoma oesophagus and compared it with EBRT alone arm with boost. All the patients were administered three cycles of three weekly neoadjuvant chemotherapy (NACT with TPF and further received a total target radiation absorbed dose of 40 Gy/20 fractions/4 weeks. All patients were divided in two arms of 30- each. In arm-1, patients received 3 sessions of ILBT boost of 5 Gy each, a week apart. In this arm, ILBT boost was given using state of the art MicroSelectron HDR brachytherapy machine with Iridium192 source. In arm-2, patients received EBRT boost of 20 Gy/10 fractions (Cobalt-60 Teletherapy machine by three field isocentric technique using Simulix HP Simulator. After completion of treatment, response was evaluated every month, in terms of local control, symptomatic relief like dysphagia, odynophagia, etc. All the patients were followed up regularly for five years. RESULTS Complete response at completion of treatment was 37% vs. 23% in arm-1 & arm-2 respectively although the results were statistically insignificant. There was marked difference in relief of dysphagia

  9. Postoperative external beam radiotherapy for medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Ha Chung; Lee, Myung Za [College of Medicine, Hanyang Univ., Seoul (Korea, Republic of)

    2000-06-01

    This study was performed to evaluate the effectiveness and tolerance of craniospinal irradiation for patients with medulloblastoma and to define the optimal radiotherapeutic regimen. We retrospectively analyzed the records of 43 patients with medulloblastoma who were treated with external beam craniospinal radiotherapy at our institution between May, 1984 and April, 1998. Median follow up period was 47 months with range of 18 to 86 months. Twenty seven patients were male and sixteen patients were female, a male to female ratio of 1.7:1. Surgery consisted of biopsy alone in 5 patients, subtotal excision in 24 patients, and gross total excision in 14 patients. All of the patients were treated with craniospinal irradiation. All of the patients except four received fat least 5,000 cGy to the posterior fossa and forty patients received more than 3,000 cGy to the spinal cord. The overall survival rates at 5 and 7 years for entire group of patients were 67% and 56%, respectively. Corresponding disease free survival rates were 60% and 51%, respectively. The rates of disease control in the posterior fossa were 77% and 67% at 5 and 7 years. Gross total excision and subtotal excision resulted in 5 year overall survival rates of 76% and 66%, respectively. in contrast, those patients who had biopsy alone had a 5 year survival rate of only 40%. Posterior fossa was a component of failure in 11 of the 18 recurrences. Seven recurrences were isolated to the posterior fossa. Four patients had neuraxis recurrences, three had distant metastasis alone and four had multiple sites of failure, all involving the primary site. Craniospinal irradiation for patients with medulloblastoma is an effective adjuvant treatment without significant treatment related toxicities. There is room for improvement in terms of posterior fossa control, especially in biopsy alone patients. The advances in radiotherapy including hyperfractionation, stereotactic radiosurgery and 3D conformal radiotherapy would be

  10. Quality improvement process to assess tattoo alignment, set-up accuracy and isocentre reproducibility in pelvic radiotherapy patients

    OpenAIRE

    Elsner, Kelly; Francis, Kate; Hruby, George; Roderick, Stephanie

    2014-01-01

    Introduction This quality improvement study tested three methods of tattoo alignment and isocentre definition to investigate if aligning lateral tattoos to minimise pitch, roll and yaw decreased set-up error, and if defining the isocentre using the lateral tattoos for cranio-caudal (CC) position improved isocentre reproducibility. The study population was patients receiving curative external beam radiotherapy (EBRT) for prostate cancer. The results are applicable to all supine pelvic EBRT pat...

  11. Combined brachytherapy and external beam radiotherapy without adjuvant androgen deprivation therapy for high-risk prostate cancer

    International Nuclear Information System (INIS)

    To report the outcomes of patients treated with combined iodine-125 (I-125) brachytherapy and external beam radiotherapy (EBRT) for high-risk prostate cancer. Between 2003 and 2009, I-125 permanent prostate brachytherapy plus EBRT was performed for 206 patients with high-risk prostate cancer. High-risk patients had prostate-specific antigen ≥ 20 ng/mL, and/or Gleason score ≥ 8, and/or Stage ≥ T3. One hundred and one patients (49.0%) received neoadjuvant androgen deprivation therapy (ADT) but none were given adjuvant ADT. Biochemical failure-free survival (BFFS) was determined using the Phoenix definition. The 5-year actuarial BFFS rate was 84.8%. The 5-year cause-specific survival and overall survival rates were 98.7% and 97.6%, respectively. There were 8 deaths (3.9%), of which 2 were due to prostate cancer. On multivariate analysis, positive biopsy core rates and the number of high-risk factors were independent predictors of BFFS. The 5-year BFFS rates for patients in the positive biopsy core rate <50% and ≥50% groups were 89.3% and 78.2%, respectively (p = 0.03). The 5-year BFFS rate for patients with the any single high-risk factor was 86.1%, compared with 73.6% for those with any 2 or all 3 high-risk factors (p = 0.03). Neoadjuvant ADT did not impact the 5-year BFFS. At a median follow-up of 60 months, high-risk prostate cancer patients undergoing combined I-125 brachytherapy and EBRT without adjuvant ADT have a high probability of achieving 5-year BFFS

  12. Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus [University Medical Center Hamburg-Eppendorf, Martini-Clinic Prostate Cancer Center, Hamburg (Germany); Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf [University Medical Center Hamburg-Eppendorf, Department of Radiation oncology, Hamburg (Germany)

    2015-04-01

    The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [German] Der Nutzen einer zusaetzlichen Hormonentzugstherapie (ADT, ''androgen deprivation therapy'') fuer Patienten mit Prostatakarzinom (PCa), welche mit einer Kombination aus HDR-Brachytherapie (HDR-BT) und perkutaner Bestrahlung (EBRT) behandelt werden, ist weiterhin ungeklaert. Fuer diese Studie wurden konsekutive, nach der D'Amico-Risikoklassifizierung in ''intermediate'' und ''high-risk'' eingeteilte Patienten ausgewaehlt, die zwischen Januar 1999 und Februar 2009 in unserem Institut eine kombinierte Therapie aus HDR-BT, EBRT ± ADT erhalten haben. Eine

  13. The effect of short term neo-adjuvant androgen deprivation on erectile function in patients treated with external beam radiotherapy for localised prostate cancer: an analysis of the 4- versus 8-month randomised trial (Irish Clinical Oncology Research Group 97-01).

    LENUS (Irish Health Repository)

    Daly, Patricia E

    2012-07-01

    Erectile dysfunction is a common consequence of external beam radiotherapy (EBRT) for prostate cancer. The addition of neo-adjuvant androgen deprivation (NAD) has an indeterminate additive effect. We examined the long-term effect on erectile function (EF) of two durations (4 months: arm 1 and 8 months: arm 2) of NAD prior to radiation (RT) for patients with localised prostate cancer from the Irish Clinical Oncology Research Group (ICORG 97-01) 4- versus 8-month trial. In this study we aimed to (1) analyse the overall effect on EF of NAD in an EBRT population, (2) compare the probability of retained EF over time in an EBRT population treated with either 4 or 8 months of NAD and (3) identify any variables such as risk group and age which may have an additive detrimental effect. This analysis provides unique long term follow up data.

  14. Optimization approaches for planning external beam radiotherapy

    Science.gov (United States)

    Gozbasi, Halil Ozan

    Cancer begins when cells grow out of control as a result of damage to their DNA. These abnormal cells can invade healthy tissue and form tumors in various parts of the body. Chemotherapy, immunotherapy, surgery and radiotherapy are the most common treatment methods for cancer. According to American Cancer Society about half of the cancer patients receive a form of radiation therapy at some stage. External beam radiotherapy is delivered from outside the body and aimed at cancer cells to damage their DNA making them unable to divide and reproduce. The beams travel through the body and may damage nearby healthy tissue unless carefully planned. Therefore, the goal of treatment plan optimization is to find the best system parameters to deliver sufficient dose to target structures while avoiding damage to healthy tissue. This thesis investigates optimization approaches for two external beam radiation therapy techniques: Intensity-Modulated Radiation Therapy (IMRT) and Volumetric-Modulated Arc Therapy (VMAT). We develop automated treatment planning technology for IMRT that produces several high-quality treatment plans satisfying provided clinical requirements in a single invocation and without human guidance. A novel bi-criteria scoring based beam selection algorithm is part of the planning system and produces better plans compared to those produced using a well-known scoring-based algorithm. Our algorithm is very efficient and finds the beam configuration at least ten times faster than an exact integer programming approach. Solution times range from 2 minutes to 15 minutes which is clinically acceptable. With certain cancers, especially lung cancer, a patient's anatomy changes during treatment. These anatomical changes need to be considered in treatment planning. Fortunately, recent advances in imaging technology can provide multiple images of the treatment region taken at different points of the breathing cycle, and deformable image registration algorithms can

  15. 20 Gy Versus 44 Gy of Supplemental External Beam Radiotherapy With Palladium-103 for Patients With Greater Risk Disease: Results of a Prospective Randomized Trial

    Energy Technology Data Exchange (ETDEWEB)

    Merrick, Gregory S., E-mail: gmerrick@urologicresearchinstitute.org [Schiffler Cancer Center/Wheeling Jesuit University, Wheeling, WV (United States); Wallner, Kent E. [Puget Sound Healthcare Corporation, University of Washington, Seattle, WA (United States); Butler, Wayne M.; Galbreath, Robert W. [Schiffler Cancer Center/Wheeling Jesuit University, Wheeling, WV (United States); Taira, Al V. [Western Radiation Oncology Inc, Mountain View, CA (United States); Orio, Peter [Department of Radiation Oncology, Dana Farber Cancer Institute/Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Adamovich, Edward [Department of Pathology, Wheeling Hospital, Wheeling, WV (United States)

    2012-03-01

    Purpose: The necessity of external beam radiotherapy (EBRT) as a supplement to prostate brachytherapy remains unknown. We report brachytherapy outcomes for patients with higher risk features randomized to substantially different supplemental EBRT regimens. Methods and Materials: Between December 1999 and June 2004, 247 patients were randomized to 20 Gy vs. 44 Gy EBRT followed by a palladium-103 boost (115 Gy vs. 90 Gy). The eligibility criteria included clinically organ-confined disease with Gleason score 7-10 and/or pretreatment prostate-specific antigen (PSA) level 10-20 ng/mL. The median follow-up period was 9.0 years. Biochemical progression-free survival (bPFS) was defined as a PSA level of {<=}0.40 ng/mL after nadir. The median day 0 prescribed dose covering 90% of the target volume was 125.7%; 80 men received androgen deprivation therapy (median, 4 months). Multiple parameters were evaluated for their effect on bPFS. Results: For the entire cohort, the cause-specific survival, bPFS, and overall survival rates were 97.7%, 93.2%, and 80.8% at 8 years and 96.9%, 93.2%, and 75.4% at 10 years, respectively. The bPFS rate was 93.1% and 93.4% for the 20-Gy and 44-Gy arms, respectively (p = .994). However, no statistically significant differences were found in cause-specific survival or overall survival were identified. When stratified by PSA level of {<=}10 ng/mL vs. >10 ng/mL, Gleason score, or androgen deprivation therapy, no statistically significant differences in bPFS were discerned between the two EBRT regimens. On multivariate analysis, bPFS was most closely related to the preimplant PSA and clinical stage. For patients with biochemically controlled disease, the median PSA level was <0.02 ng/mL. Conclusion: The results of the present trial strongly suggest that two markedly different supplemental EBRT regimens result in equivalent cause-specific survival, bPFS, and overall survival. It is probable that the lack of benefit for a higher supplemental EBRT dose

  16. High-Dose-Rate Brachytherapy and External-Beam Radiotherapy for Hormone-Naieve Low- and Intermediate-Risk Prostate Cancer: A 7-Year Experience

    Energy Technology Data Exchange (ETDEWEB)

    Aluwini, Shafak, E-mail: s.aluwini@erasmusmc.nl [Department of Radiation Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Rooij, Peter H. van [Department of Radiation Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Kirkels, Wim J. [Department of Urology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Jansen, Peter P.; Praag, John O. [Department of Radiation Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Bangma, Chris H. [Department of Urology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Kolkman-Deurloo, Inger-Karine K. [Department of Radiation Oncology, Erasmus MC, Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2012-08-01

    Purpose: To report clinical outcomes and early and late complications in 264 hormone-naieve patients with low- and intermediate-risk prostate cancer treated with high-dose-rate brachytherapy (HDR-BT) in combination with external-beam radiotherapy (EBRT). Methods and Materials: Between February 2000 and July 2007, 264 patients underwent HDR-BT in combination with EBRT as a treatment for their low- to intermediate-risk prostate cancer. The HDR-BT was performed using ultrasound-based implantation. The total HDR-BT dose was 18 Gy in 3 fractions within 24 h, with a 6-h minimum interval. The EBRT started 2 weeks after HDR-BT and was delivered in 25 fractions of 1.8 Gy to 45 Gy within 5 weeks. Results: After a mean follow-up of 74.5 months, 4 patients (1.5%) showed prostate-specific antigen progression according to the American Society for Radiation Oncology definition and 8 patients (3%) according to the Phoenix definition. A biopsy-proven local recurrence was registered in 1 patient (0.4%), and clinical progression (bone metastases) was documented in 2 patients (0.7%). Seven-year actuarial freedom from biochemical failure was 97%, and 7-year disease-specific survival and overall survival were 100% and 91%, respectively. Toxicities were comparable to other series. Conclusions: Treatment with interstitial HDR-BT plus EBRT shows a low incidence of late complications and a favorable oncologic outcome after 7 years follow-up.

  17. Registering prostate external beam radiotherapy with a boost from high-dose-rate brachytherapy: a comparative evaluation of deformable registration algorithms

    International Nuclear Information System (INIS)

    Registering CTs for patients receiving external beam radiotherapy (EBRT) with a boost dose from high-dose-rate brachytherapy (HDR) can be challenging due to considerable image discrepancies (e.g. rectal fillings, HDR needles, HDR artefacts and HDR rectal packing materials). This study is the first to comparatively evaluate image processing and registration methods used to register the rectums in EBRT and HDR CTs of prostate cancer patients. The focus is on the rectum due to planned future analysis of rectal dose-volume response. For 64 patients, the EBRT CT was retrospectively registered to the HDR CT with rigid registration and non-rigid registration methods in VelocityAI. Image processing was undertaken on the HDR CT and the rigidly-registered EBRT CT to reduce the impact of discriminating features on alternative non-rigid registration methods applied in the software suite for Deformable Image Registration and Adaptive Radiotherapy Research (DIRART) using the Horn-Schunck optical flow and Demons algorithms. The propagated EBRT-rectum structures were compared with the HDR structure using the Dice similarity coefficient (DSC), Hausdorff distance (HD) and average surface distance (ASD). The image similarity was compared using mutual information (MI) and root mean squared error (MSE). The displacement vector field was assessed via the Jacobian determinant (JAC). The post-registration alignments of rectums for 21 patients were visually assessed. The greatest improvement in the median DSC relative to the rigid registration result was 35 % for the Horn-Schunck algorithm with image processing. This algorithm also provided the best ASD results. The VelocityAI algorithms provided superior HD, MI, MSE and JAC results. The visual assessment indicated that the rigid plus deformable multi-pass method within VelocityAI resulted in the best rectum alignment. The DSC, ASD and HD improved significantly relative to the rigid registration result if image processing was applied prior

  18. Characterization of a homemade ionization chamber for radiotherapy beams.

    Science.gov (United States)

    Neves, Lucio P; Perini, Ana P; dos Santos, Gelson P; Xavier, Marcos; Khoury, Helen J; Caldas, Linda V E

    2012-07-01

    A homemade cylindrical ionization chamber was studied for routine use in therapy beams of (60)Co and X-rays. Several characterization tests were performed: leakage current, saturation, ion collection efficiency, polarity effect, stability, stabilization time, chamber orientation and energy dependence. All results obtained were within international recommendations. Therefore the homemade ionization chamber presents usefulness for routine dosimetric procedures in radiotherapy beams.

  19. Characterization of a homemade ionization chamber for radiotherapy beams.

    Science.gov (United States)

    Neves, Lucio P; Perini, Ana P; dos Santos, Gelson P; Xavier, Marcos; Khoury, Helen J; Caldas, Linda V E

    2012-07-01

    A homemade cylindrical ionization chamber was studied for routine use in therapy beams of (60)Co and X-rays. Several characterization tests were performed: leakage current, saturation, ion collection efficiency, polarity effect, stability, stabilization time, chamber orientation and energy dependence. All results obtained were within international recommendations. Therefore the homemade ionization chamber presents usefulness for routine dosimetric procedures in radiotherapy beams. PMID:22153889

  20. Impact of the target volume (prostate alone vs. prostate with seminal vesicles) and fraction dose (1.8 Gy vs. 2.0 Gy) on quality of life changes after external-beam radiotherapy for prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Eble, Michael J. [Dept. of Radiotherapy, RWTH Aachen (Germany); Pinkawa, Michael; Piroth, Marc D.; Fischedick, Karin; Holy, Richard; Klotz, Jens; Nussen, Sandra; Krenkel, Barbara

    2009-11-15

    Purpose: to evaluate the impact of the clinical target volume (CTV) and fraction dose on quality of life (QoL) after external-beam radiotherapy (EBRT) for prostate cancer. Patients and methods: a group of 283 patients has been surveyed prospectively before, at the last day, at a median time of 2 months and 15 months after EBRT (70.2-72 Gy) using a validated questionnaire (Expanded Prostate Cancer Index Composite). FBRT of prostate alone (P, n = 70) versus prostate with seminal vesicles (PS, n = 213) was compared. Differences of fraction doses (1.8 Gy, n = 80, vs. 2.0 Gy, n = 69) have been evaluated in the patient group receiving a total dose of 72 Gy. Results: significantly higher bladder and rectum volumes were found at all dose levels for the patients with PS versus P within the CTV (p < 0.001). Similar volumes resulted in the groups with different fraction doses. Paradoxically, bowel function scores decreased significantly less 2 and 15 months after EBRT of PS versus P. 2 months after EBRT, patients with a fraction dose of 2.0 Gy versus 1.8 Gy reported pain with urination ({>=} once a day in 12% vs. 3%; p = 0.04) and painful bowel movements ({>=} rarely in 46% vs. 29%; p = 0.05) more frequently. No long-term differences were found. Conclusion: the risk of adverse QoL changes after EBRT for prostate cancer cannot be derived from the dose-volume histogram alone. Seminal vesicles can be included in the CTV up to a moderate total dose without adverse effects on QoL. Apart from a longer recovery period, higher fraction doses were not associated with higher toxicity. (orig.)

  1. External Beam Radiation in Differentiated Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Salem Billan

    2016-01-01

    Full Text Available The treatment of differentiated thyroid carcinoma (DTC is surgery followed in some cases by adjuvant treatment, mostly with radioactive iodine (RAI. External beam radiotherapy (EBRT is less common and not a well-established treatment modality in DTC. The risk of recurrence depends on three major prognostic factors: extra-thyroid extension, patient’s age, and tumor with reduced iodine uptake. Increased risk for recurrence is a major factor in the decision whether to treat the patient with EBRT. Data about the use of EBRT in DTC are limited to small retrospective studies. Most series have demonstrated an increase in loco-regional control. The risk/benefit from giving EBRT requires careful patient selection. Different scoring systems have been proposed by different investigators and centers. The authors encourage clinicians treating DTC to become familiarized with those scoring systems and to use them in the management of different cases. The irradiated volume should include areas of risk for microscopic disease. Determining those areas in each case can be difficult and requires detailed knowledge of the surgery and pathological results, and also understanding of the disease-spreading pattern. Treatment with EBRT in DTC can be beneficial, and data support the use of EBRT in high-risk patients. Randomized controlled trials are needed for better confirmation of the role of EBRT.

  2. External beam radiotherapy synergizes 188Re-liposome against human esophageal cancer xenograft and modulates 188Re-liposome pharmacokinetics

    Directory of Open Access Journals (Sweden)

    Chang CH

    2015-05-01

    Full Text Available Chih-Hsien Chang,1,2 Shin-Yi Liu,3 Chih-Wen Chi,3 Hsiang-Lin Yu,1 Tsui-Jung Chang,1 Tung-Hu Tsai,4 Te-Wei Lee,1 Yu-Jen Chen3–5 1Isotope Application Division, Institute of Nuclear Energy Research, Taoyuan, Taiwan; 2Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, 3Department of Medical Research MacKay Memorial Hospital, 4Institute of Traditional Medicine, National Yang-Ming University, 5Department of Radiation Oncology, MacKay Memorial Hospital, Taipei, Taiwan Abstract: External beam radiotherapy (EBRT treats gross tumors and local microscopic diseases. Radionuclide therapy by radioisotopes can eradicate tumors systemically. Rhenium 188 (188Re-liposome, a nanoparticle undergoing clinical trials, emits gamma rays for imaging validation and beta rays for therapy, with biodistribution profiles preferential to tumors. We designed a combinatory treatment and examined its effects on human esophageal cancer xenografts, a malignancy with potential treatment resistance and poor prognosis. Human esophageal cancer cell lines BE-3 (adenocarcinoma and CE81T/VGH (squamous cell carcinoma were implanted and compared. The radiochemical purity of 188Re-liposome exceeded 95%. Molecular imaging by NanoSPECT/CT showed that BE-3, but not CE81T/VGH, xenografts could uptake the 188Re-liposome. The combination of EBRT and 188Re-liposome inhibited tumor regrowth greater than each treatment alone, as the tumor growth inhibition rate was 30% with EBRT, 25% with 188Re-liposome, and 53% with the combination treatment at 21 days postinjection. Combinatory treatment had no additive adverse effects and significant biological toxicities on white blood cell counts, body weight, or liver and renal functions. EBRT significantly enhanced the excretion of 188Re-liposome into feces and urine. In conclusion, the combination of EBRT with 188Re-liposome might be a potential treatment modality for esophageal cancer. Keywords: Radionuclide

  3. Radiation-related quality of life parameters after targeted intraoperative radiotherapy versus whole breast radiotherapy in patients with breast cancer: results from the randomized phase III trial TARGIT-A

    International Nuclear Information System (INIS)

    Intraoperative radiotherapy (IORT) is a new treatment approach for early stage breast cancer. This study reports on the effects of IORT on radiation-related quality of life (QoL) parameters. Two hundred and thirty women with stage I-III breast cancer (age, 31 to 84 years) were entered into the study. A single-center subgroup of 87 women from the two arms of the randomized phase III trial TARGIT-A (TARGeted Intra-operative radioTherapy versus whole breast radiotherapy for breast cancer) was analyzed. Furthermore, results were compared to non-randomized control groups: n = 90 receiving IORT as a tumor bed boost followed by external beam whole breast radiotherapy (EBRT) outside of TARGIT-A (IORT-boost), and n = 53 treated with EBRT followed by an external-beam boost (EBRT-boost). QoL was collected using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaires C30 (QLQ-C30) and BR23 (QLQ-BR23). The mean follow-up period in the TARGIT-A groups was 32 versus 39 months in the non-randomized control groups. Patients receiving IORT alone reported less general pain (21.3 points), breast (7.0 points) and arm (15.1 points) symptoms, and better role functioning (78.7 points) as patients receiving EBRT (40.9; 19.0; 32.8; and 60.5 points, respectively, P < 0.01). Patients receiving IORT alone also had fewer breast symptoms than TARGIT-A patients receiving IORT followed by EBRT for high risk features on final pathology (IORT-EBRT; 7.0 versus 29.7 points, P < 0.01). There were no significant differences between TARGIT-A patients receiving IORT-EBRT compared to non-randomized IORT-boost or EBRT-boost patients and patients receiving EBRT without a boost. In the randomized setting, important radiation-related QoL parameters after IORT were superior to EBRT. Non-randomized comparisons showed equivalent parameters in the IORT-EBRT group and the control groups

  4. TECHNOLOGIES FOR DELIVERY OF PROTON AND ION BEAMS FOR RADIOTHERAPY

    CERN Document Server

    Owen, H; Alonso, J; Mackay, R

    2014-01-01

    Recent developments for the delivery of proton and ion beam therapy have been significant, and a number of technological solutions now exist for the creation and utilisation of these particles for the treatment of cancer. In this paper we review the historical development of particle accelerators used for external beam radiotherapy and discuss the more recent progress towards more capable and cost-effective sources of particles.

  5. Technologies for Delivery of Proton and Ion Beams for Radiotherapy

    CERN Document Server

    Owen, Hywel; Alonso, Jose; MacKay, Ranald

    2013-01-01

    Recent developments for the delivery of proton and ion beam therapy have been significant, and a number of technological solutions now exist for the creation and utilisation of these particles for the treatment of cancer. In this paper we review the historical development of particle accelerators used for external beam radiotherapy and discuss the more recent progress towards more capable and cost-effective sources of particles.

  6. Diaphragm motion characterization using chest motion data for biomechanics-based lung tumor tracking during EBRT

    Science.gov (United States)

    Karami, Elham; Gaede, Stewart; Lee, Ting-Yim; Samani, Abbas

    2016-03-01

    Despite recent advances in image-guided interventions, lung cancer External Beam Radiation Therapy (EBRT) is still very challenging due to respiration induced tumor motion. Among various proposed methods of tumor motion compensation, real-time tumor tracking is known to be one of the most effective solutions as it allows for maximum normal tissue sparing, less overall radiation exposure and a shorter treatment session. As such, we propose a biomechanics-based real-time tumor tracking method for effective lung cancer radiotherapy. In the proposed algorithm, the required boundary conditions for the lung Finite Element model, including diaphragm motion, are obtained using the chest surface motion as a surrogate signal. The primary objective of this paper is to demonstrate the feasibility of developing a function which is capable of inputting the chest surface motion data and outputting the diaphragm motion in real-time. For this purpose, after quantifying the diaphragm motion with a Principal Component Analysis (PCA) model, correlation coefficient between the model parameters of diaphragm motion and chest motion data was obtained through Partial Least Squares Regression (PLSR). Preliminary results obtained in this study indicate that the PCA coefficients representing the diaphragm motion can be obtained through chest surface motion tracking with high accuracy.

  7. Beam monitoring in radiotherapy and hadron-therapy

    International Nuclear Information System (INIS)

    Radiotherapy techniques have evolved over the past twenty years. For photon beams, the development of tools such as multi leaf collimators, machines such as Cyberknife or tomo-therapy, have improved the conformation of treatments to the tumor volume and lowered maximum dose to healthy tissue. In another register, the use of proton-therapy is expanding in all countries and the development of carbon ions beams for hadron-therapy is also increasing. If techniques improve, the control requirements for the monitoring of the dose administered to patients are always the same. This document presents, first, the ins and outs of the different techniques of external beam radiotherapy: photon treatments, protons and hadrons. Starting from the basis of clinical requirements, it sets the variables to be measured in order to ensure the quality of treatment for the different considered modalities. It then describes some implementations, based on precise and rigorous specifications, for the monitoring and measurement of beams delivered by external beam radiotherapy equipments. Two instrumental techniques are particularly highlighted, plastic scintillators dosimetry for the control of megavoltage photon beams and ionization chamber dosimetry applied to proton-therapy or radiobiology experiments conducted at the GANIL facility. Analyzes and perspectives, based on the recent developments of treatment techniques, are delivered in conclusion and can serve as guide for future instrumental developments. (author)

  8. Improving anatomical mapping of complexly deformed anatomy for external beam radiotherapy and brachytherapy dose accumulation in cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Vásquez Osorio, Eliana M., E-mail: e.vasquezosorio@erasmusmc.nl; Kolkman-Deurloo, Inger-Karine K.; Schuring-Pereira, Monica; Zolnay, András; Heijmen, Ben J. M.; Hoogeman, Mischa S. [Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam 3075 (Netherlands)

    2015-01-15

    Purpose: In the treatment of cervical cancer, large anatomical deformations, caused by, e.g., tumor shrinkage, bladder and rectum filling changes, organ sliding, and the presence of the brachytherapy (BT) applicator, prohibit the accumulation of external beam radiotherapy (EBRT) and BT dose distributions. This work proposes a structure-wise registration with vector field integration (SW+VF) to map the largely deformed anatomies between EBRT and BT, paving the way for 3D dose accumulation between EBRT and BT. Methods: T2w-MRIs acquired before EBRT and as a part of the MRI-guided BT procedure for 12 cervical cancer patients, along with the manual delineations of the bladder, cervix-uterus, and rectum-sigmoid, were used for this study. A rigid transformation was used to align the bony anatomy in the MRIs. The proposed SW+VF method starts by automatically segmenting features in the area surrounding the delineated organs. Then, each organ and feature pair is registered independently using a feature-based nonrigid registration algorithm developed in-house. Additionally, a background transformation is calculated to account for areas far from all organs and features. In order to obtain one transformation that can be used for dose accumulation, the organ-based, feature-based, and the background transformations are combined into one vector field using a weighted sum, where the contribution of each transformation can be directly controlled by its extent of influence (scope size). The optimal scope sizes for organ-based and feature-based transformations were found by an exhaustive analysis. The anatomical correctness of the mapping was independently validated by measuring the residual distances after transformation for delineated structures inside the cervix-uterus (inner anatomical correctness), and for anatomical landmarks outside the organs in the surrounding region (outer anatomical correctness). The results of the proposed method were compared with the results of the

  9. Improving anatomical mapping of complexly deformed anatomy for external beam radiotherapy and brachytherapy dose accumulation in cervical cancer

    International Nuclear Information System (INIS)

    Purpose: In the treatment of cervical cancer, large anatomical deformations, caused by, e.g., tumor shrinkage, bladder and rectum filling changes, organ sliding, and the presence of the brachytherapy (BT) applicator, prohibit the accumulation of external beam radiotherapy (EBRT) and BT dose distributions. This work proposes a structure-wise registration with vector field integration (SW+VF) to map the largely deformed anatomies between EBRT and BT, paving the way for 3D dose accumulation between EBRT and BT. Methods: T2w-MRIs acquired before EBRT and as a part of the MRI-guided BT procedure for 12 cervical cancer patients, along with the manual delineations of the bladder, cervix-uterus, and rectum-sigmoid, were used for this study. A rigid transformation was used to align the bony anatomy in the MRIs. The proposed SW+VF method starts by automatically segmenting features in the area surrounding the delineated organs. Then, each organ and feature pair is registered independently using a feature-based nonrigid registration algorithm developed in-house. Additionally, a background transformation is calculated to account for areas far from all organs and features. In order to obtain one transformation that can be used for dose accumulation, the organ-based, feature-based, and the background transformations are combined into one vector field using a weighted sum, where the contribution of each transformation can be directly controlled by its extent of influence (scope size). The optimal scope sizes for organ-based and feature-based transformations were found by an exhaustive analysis. The anatomical correctness of the mapping was independently validated by measuring the residual distances after transformation for delineated structures inside the cervix-uterus (inner anatomical correctness), and for anatomical landmarks outside the organs in the surrounding region (outer anatomical correctness). The results of the proposed method were compared with the results of the

  10. Bilateral Rhegmatogenous Retinal Detachment during External Beam Radiotherapy

    Directory of Open Access Journals (Sweden)

    Takako Hidaka

    2016-06-01

    Full Text Available Herein, we report a case of nontraumatic bilateral rhegmatogenous retinal detachment (RRD during external beam radiotherapy for nonocular tumor, presented as an observational case study in conjunction with a review of the relevant literature. A 65-year-old male was referred to our hospital due to bilateral RRD. He underwent a biopsy for a tumor of the left frontal lobe 4 months prior to presentation, and the tumor had been diagnosed as primary central nerve system B-cell type lymphoma. He received chemotherapy and external beam radiotherapy for 1 month. There were no traumatic episodes. Bilateral retinal detachment occurred during a series of radiotherapies. Simultaneous nontraumatic bilateral retinal detachment is rare. The effects of radiotherapy on ocular functionality, particularly in cases involving retinal adhesion and vitreous contraction, may include RRD. Thus, it is necessary to closely monitor the eyes of patients undergoing radiotherapy, particularly those undergoing surgery for retinal detachment and those with a history of photocoagulation for retinal tears, a relevant family history, or risk factors known to be associated with RRD.

  11. Intraoperative radiotherapy (IORT is an option for patients with localized breast recurrences after previous external-beam radiotherapy

    Directory of Open Access Journals (Sweden)

    Schaefer Joerg

    2007-09-01

    Full Text Available Abstract Background For patients suffering of recurrent breast cancer within the irradiated breast, generally mastectomy is recommended. The normal tissue tolerance does not permit a second full-dose course of radiotherapy to the entire breast after a second breast-conserving surgery (BCS. A novel option is to treat these patients with partial breast irradiation (PBI. This approach is based on the hypothesis that re-irradiation of a limited volume will be effective and result in an acceptable frequency of side effects. The following report presents a single center experience with intraoperative radiotherapy (IORT during excision of recurrent breast cancer in the previously irradiated breast. Methods Between 4/02 and 11/06, 15 patients were treated for in-breast recurrences at a median of 10 years (3–25 after previous EBRT (10 recurrences in the initial tumor bed, 3 elsewhere in-breast failures, 2 invasive recurrences after previous DCIS. Additional 2 patients were selected for IORT with new primary breast cancer after previous partial breast EBRT for treatment of Hodgkin's disease. IORT with a single dose of 14.7 – 20 Gy 50 kV X-rays at the applicator surface was delivered with the Intrabeam™-device (Carl Zeiss, Oberkochen, Germany. Results After a median follow-up of 26 months (1–60, no local recurrence occurred. 14 out of 17 patients are alive and free of disease progression. Two patients are alive with distant metastases. One patient died 26 months after BCS/IORT due to pulmonary metastases diagnosed 19 months after BCS/IORT. Acute toxicity after IORT was mild with no Grade 3/4 toxicities and cosmetic outcome showed excellent/good/fair results in 7/7/3 cases. Conclusion IORT for recurrent breast cancer using low energy X-rays is a valuable option for patients with recurrent breast cancer after previous radiotherapy.

  12. External-beam radiotherapy for clinically localized prostate cancer in Osaka, Japan, 1995-2006. Time trends, outcome, and risk stratification

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Yasuo; Inoue, Takehiro [Dept. of Radiation Oncology, Osaka Univ. Graduate School of Medicine (Japan); Suzuki, Osamu [Dept. of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases (Japan); Kobayashi, Kana; Yamazaki, Hideya [Dept. of Radiology, Kyoto Prefectural Univ. of Medicine (Japan); Teshima, Teruki [Dept. of Radiology, Suita Municipal Hospital, Osaka (Japan); Yamada, Yuji [Dept. of Radiation Oncology, Kansai Rosai Hospital, Hyogo (Japan); Kotsuma, Tadayuki [Dept. of Radiology, National Hospital Organization Osaka National Hospital (Japan); Koizumi, Masahiko [Faculty of Radiological Technology, School of Health Sciences, Fujita Health Univ., Aichi (Japan); Kagawa, Kazufumi [Dept. of Radiation Oncology, NTT West Osaka Hospital (Japan); Chatani, Masashi [Dept. of Radiology, Osaka Rosai Hospital (Japan); Shimamoto, Shigetoshi [Dept. of Radiation Oncology, Osaka Prefectural General Medical Center (Japan); Tanaka, Eiichi [Dept. of Radiation Oncology, Rinku General Medical Center, Osaka (Japan)

    2009-07-15

    Purpose: To establish an initial database of external-beam radiotherapy (EBRT) for clinically localized prostate cancer used in Osaka, Japan, and, by analyzing the results of the Osaka multicenter cooperative study, to determine time trends, outcome, and applicability of existing and the authors' original risk stratification methods. Patients and methods: Data of 652 patients with clinically localized prostate cancer (T1-4 NO MO) were accrued from July to December 2007. These patients had been treated from 1995 through 2006 with consecutive definitive EBRT of {>=} 60 Gy at eleven institutions, mainly in Osaka. Altogether, 436 patients were eligible for analysis using several risk stratification methods, namely, those of D'Amico et al., the National Comprehensive Cancer Network (NCCN), and Seattle, as well as the authors' original Prostate Cancer Risk Index (PRIX). Results: The number of patients showed a tenfold increase over 10 years, together with a rapid spread of the use of Gleason Score from 0% to > 90% of cases. The dominant RT dose fractionation was 70 Gy/35 fractions (87%). Hormone therapy had been administered to 95% of the patients and the higher PRIX corresponded to the higher rate of hormone usage. 3- and 5-year biochemical relapse-free survival (bRFS) rates were 85% and 70%, respectively. The D'Amico (p = 0.132), NCCN (p = 0.138), Seattle (p = 0.041) and PRIX (p = 0.044) classifications showed weak or no correlation with bRFS, while the own modified three-class PRIX (PRIX 0, 1-5, 6) showed a strong correlation (p = 0.002). Conclusion: The use of prostate EBRT in Japan is still in its infancy, but is rapidly expanding. The short-term outcomes have been satisfactory considering the moderate RT dose. A very high rate of hormone usage may affect the outcome favorably, but also may compromise the usefulness of current risk stratification. (orig.)

  13. Detection of Local, Regional, and Distant Recurrence in Patients With PSA Relapse After External-Beam Radiotherapy Using 11C-Choline Positron Emission Tomography

    International Nuclear Information System (INIS)

    Purpose: An elevated serum prostate-specific antigen (PSA) level cannot distinguish between local-regional recurrences and the presence of distant metastases after treatment with curative intent for prostate cancer. With the advent of salvage treatment such as cryotherapy, it has become important to localize the site of recurrence (local or distant). In this study, the potential of 11C-choline positron emission tomography (PET) to identify site of recurrence was investigated in patients with rising PSA after external-beam radiotherapy (EBRT). Methods and Materials: Seventy patients with histologically proven prostate cancer treated with EBRT and showing biochemical recurrence as defined by American Society for Therapeutic Radiology and Oncology consensus statement and 10 patients without recurrence underwent a PET scan using 400 MBq 11C-choline intravenously. Biopsy-proven histology from the site of suspicion, findings with other imaging modalities, clinical follow-up and/or response to adjuvant therapy were used as comparative references. Results: None of the 10 patients without biochemical recurrence had a positive PET scan. Fifty-seven of 70 patients with biochemical recurrence (median PSA 9.1 ng/mL; mean PSA 12.3 ng/mL) showed an abnormal uptake pattern (sensitivity 81%). The site of recurrence was only local in 41 of 57 patients (mean PSA 11.1 ng/mL at scan), locoregionally and/or distant in 16 of 57 patients (mean PSA 17.7 ng/mL). Overall the positive predictive value and negative predictive value for 11C-choline PET scan were 1.0 and 0.44 respectively. Accuracy was 84%. Conclusions: 11C-choline PET scan is a sensitive technique to identify the site of recurrence in patients with PSA relapse after EBRT for prostate cancer.

  14. Length and quality of survival after external-beam radiotherapy with concurrent continuous 5-fluorouracil infusion for locally unresectable pancreatic cancer

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to evaluate whether external-beam radiotherapy (EBRT) with concurrent continuous 5-fluorouracil (5-FU) infusion affects the length and quality of survival in patients with locally unresectable pancreatic cancer. Methods: Thirty-one patients with histologically proven locally advanced and unresectable pancreatic cancer without distant metastases were evaluated in this prospective randomized trial. Sixteen patients received EBRT (50.4 Gy/28 fractions) with concurrent continuous infusion of 5-FU (200 mg/m2/day), whereas 15 patients received no chemoradiation. The length and quality of survival was analyzed and compared for the two groups. Results: The median survival of 13.2 months and the 1-year survival rate of 53.3% in the chemoradiation group were significantly better than the respective 6.4 months and 0% in the group without chemoradiotherapy (p=0.0009). The average monthly Karnofsky score, a quality of life indicator, was 77.1 in the chemoradiation group, which was significantly higher than the 65.5 in the group without chemoradiotherapy (p<0.0001). The number of hospital days per month of survival was significantly less in the chemoradiation than in the no-therapy group (12.3 vs. 19.0 days, p<0.05). In the chemoradiation group, 5 patients (31%) had a partial response, and 9 (56%) had radiologically stable disease at a median duration of 6.1 months. The patients who had chemoradiation had a lower rate of liver and peritoneal metastases than patients without chemoradiotherapy (31% vs. 64%). Of 10 patients who experienced pain before chemoradiation, 8 (80%) received pain relief that lasted a median of 5.2 months. Conclusions: EBRT with concurrent continuous 5-FU infusion increased the length and quality of survival as compared to no chemoradiotherapy and provided a definite palliative benefit for patients with unresectable pancreatic cancer

  15. Characterization of a homemade ionization chamber for radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Lucio P., E-mail: lpneves@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Perini, Ana P., E-mail: aperini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Santos, Gelson P. dos, E-mail: gpsantos@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Xavier, Marcos, E-mail: mxavier@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.br [Universidade Federal de Pernambuco, Departamento de Energia Nuclear, Av. Prof. Luiz Freire 1000, 50740-540 Recife (Brazil); Caldas, Linda V.E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo (Brazil)

    2012-07-15

    A homemade cylindrical ionization chamber was studied for routine use in therapy beams of {sup 60}Co and X-rays. Several characterization tests were performed: leakage current, saturation, ion collection efficiency, polarity effect, stability, stabilization time, chamber orientation and energy dependence. All results obtained were within international recommendations. Therefore the homemade ionization chamber presents usefulness for routine dosimetric procedures in radiotherapy beams. - Highlights: Black-Right-Pointing-Pointer A homemade ionization chamber was studied for routine use in radiotherapy. Black-Right-Pointing-Pointer Several characterization tests were performed and the results were satisfactory. Black-Right-Pointing-Pointer This chamber was compared to commercial ones and the results were similar. Black-Right-Pointing-Pointer This chamber is suitable for calibration procedures in {sup 60}Co beams.

  16. A device for a proton beam energy control for radiotherapy

    International Nuclear Information System (INIS)

    A Medical-Technical Facility for hadron radiotherapy based on the JINR DLNP phasotron has been constructed and put into operation. Upgrading of methods, hardware and software for radiotherapy is one of the main tasks for further development of the Facility. This article concerns one of the fields of this work, that is the development of equipment for dynamic irradiation of a deep lying target - the construction of a device for the proton beam energy control and measurement of its depth-dose curve in a treatment room. (author)

  17. A Device for a Proton Beam Energy Control for Radiotherapy

    CERN Document Server

    Agapov, A V; Molokanov, A G; Shvidkii, S V

    2004-01-01

    A Medical-Technical Facility for hadron radiotherapy based on DLNP JINR phasotron has been constructed and put into operation. Upgrading of methods, hardware and software for radiotherapy is one of the main tasks for further development of the Facility. This article concerns one of the fields of this work, that is the development of equipment for dynamic irradiation of deep lying target - the construction of a device for the proton beam energy control and measurement of its depth-dose curve in a treatment room.

  18. Olfactory neural tumours - the role of external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Slevin, N.J.; Irwin, C.J.R.; Banerjee, S.S.; Path, F.R.C.; Gupta, N.K.; Farrington, W.T. [Christie Hospital and Holt Radium Inst., Manchester (United Kingdom)

    1996-11-01

    Olfactory neuroblastoma is an uncommon tumour arising in the nasal cavity or paranasal sinuses. We report the management of nine cases treated with external beam radiotherapy subsequent to surgery, either attempted definitive removal or biopsy only. Recent refinements in pathological evaluation of these tumours are discussed. Seven cases were deemed classical olfactory neuroblastoma whilst two were classified as neuroendocrine carcinoma. The clinical features, radiotherapy technique and variable natural history are presented. Seven of eight patients treated radically were controlled locally, with a minimum follow-up of two years. Three patients developed cervical lymph node disease and three patients died of systemic metastatic disease. Suggestions are made as to which patients should have en-bloc resection rather than definitive radiotherapy. (author).

  19. Olfactory neural tumours - the role of external beam radiotherapy

    International Nuclear Information System (INIS)

    Olfactory neuroblastoma is an uncommon tumour arising in the nasal cavity or paranasal sinuses. We report the management of nine cases treated with external beam radiotherapy subsequent to surgery, either attempted definitive removal or biopsy only. Recent refinements in pathological evaluation of these tumours are discussed. Seven cases were deemed classical olfactory neuroblastoma whilst two were classified as neuroendocrine carcinoma. The clinical features, radiotherapy technique and variable natural history are presented. Seven of eight patients treated radically were controlled locally, with a minimum follow-up of two years. Three patients developed cervical lymph node disease and three patients died of systemic metastatic disease. Suggestions are made as to which patients should have en-bloc resection rather than definitive radiotherapy. (author)

  20. Validating dose rate calibration of radiotherapy photon beams through IAEA/WHO postal audit dosimetry service

    International Nuclear Information System (INIS)

    In external beam radiation therapy (EBRT), the quality assurance (QA) of the radiation beam is crucial to the accurate delivery of the prescribed dose to the patient. One of the dosimetric parameters that require monitoring is the beam output, specified as the dose rate on the central axis under reference conditions. The aim of this project was to validate dose rate calibration of megavoltage photon beams using the International Atomic Energy Agency (IAEA)/World Health Organisation (WHO) postal audit dosimetry service. Three photon beams were audited: a 6 MV beam from the low-energy linac and 6 and 18 MV beams from a dual high-energy linac. The agreement between our stated doses and the IAEA results was within 1% for the two 6 MV beams and within 2% for the 18 MV beam. The IAEA/WHO postal audit dosimetry service provides an independent verification of dose rate calibration protocol by an international facility. (author)

  1. Compensation techniques in NIRS proton beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Akanuma, A. (Univ. of Tokyo, Japan); Majima, H.; Furukawa, S.

    1982-09-01

    Proton beam has the dose distribution advantage in radiation therapy, although it has little advantage in biological effects. One of the best advantages is its sharp fall off of dose after the peak. With proton beam, therefore, the dose can be given just to cover a target volume and potentially no dose is delivered thereafter in the beam direction. To utilize this advantage, bolus techniques in conjunction with CT scanning are employed in NIRS proton beam radiation therapy planning. A patient receives CT scanning first so that the target volume can be clearly marked and the radiation direction and fixation method can be determined. At the same time bolus dimensions are calculated. The bolus frames are made with dental paraffin sheets according to the dimensions. The paraffin frame is replaced with dental resin. Alginate (a dental impression material with favorable physical density and skin surface contact) is now employed for the bolus material. With fixation device and bolus on, which are constructed individually, the patient receives CT scanning again prior to a proton beam treatment in order to prove the devices are suitable. Alginate has to be poured into the frame right before each treatments. Further investigations are required to find better bolus materials and easier construction methods.

  2. Monitoring external beam radiotherapy using real-time beam visualization

    International Nuclear Information System (INIS)

    Purpose: To characterize the performance of a novel radiation therapy monitoring technique that utilizes a flexible scintillating film, common optical detectors, and image processing algorithms for real-time beam visualization (RT-BV). Methods: Scintillating films were formed by mixing Gd2O2S:Tb (GOS) with silicone and casting the mixture at room temperature. The films were placed in the path of therapeutic beams generated by medical linear accelerators (LINAC). The emitted light was subsequently captured using a CMOS digital camera. Image processing algorithms were used to extract the intensity, shape, and location of the radiation field at various beam energies, dose rates, and collimator locations. The measurement results were compared with known collimator settings to validate the performance of the imaging system. Results: The RT-BV system achieved a sufficient contrast-to-noise ratio to enable real-time monitoring of the LINAC beam at 20 fps with normal ambient lighting in the LINAC room. The RT-BV system successfully identified collimator movements with sub-millimeter resolution. Conclusions: The RT-BV system is capable of localizing radiation therapy beams with sub-millimeter precision and tracking beam movement at video-rate exposure

  3. Modelling beam transport and biological effectiveness to develop treatment planning for ion beam radiotherapy

    CERN Document Server

    Grzanka, Leszek

    2014-01-01

    Radiation therapy with carbon ions is a novel technique of cancer radiotherapy, applicable in particular to treating radioresistant tumours at difficult localisations. Therapy planning, where the medical physicist, following the medical prescription, finds the optimum distribution of cancer cells to be inactivated by their irradiation over the tumour volume, is a basic procedure of cancer radiotherapy. The main difficulty encountered in therapy planning for ion radiotherapy is to correctly account for the enhanced radiobiological effectiveness of ions in the Spread Out Bragg Peak (SOBP) region over the tumour volume. In this case, unlike in conventional radiotherapy with photon beams, achieving a uniform dose distribution over the tumour volume does not imply achieving uniform cancer cell inactivation. In this thesis, an algorithm of the basic element (kernel) of a treatment planning system (TPS) for carbon ion therapy is developed. The algorithm consists of a radiobiological part which suitably corrects for ...

  4. Treatment results of radical radiotherapy of carcinoma uterine cervix using external beam radiotherapy and high dose rate intracavitary radiotherapy

    Directory of Open Access Journals (Sweden)

    Azad S

    2010-01-01

    Full Text Available Aim: To report the outcome of carcinoma cervix patients treated radically by external beam radiotherapy and high dose rate intracavitary radiotherapy. Material and Methods: From January 2005 to December 2006, a total of 709 newly diagnosed cases of carcinoma cervix were reported in our department. All cases were staged according to the International Federation of Gynecologist and Oncologist staging system. Out of 709 cases, 342 completed radical radiotherapy and were retrospectively analyzed for the presence of local residual disease, local recurrence, distant metastases, radiation reaction, and disease free survival. Results: There were 11(3.22%, 82(23.98%, 232(67.83%, and 17(4.97% patients in stages I, II, III, and IV, respectively. The median follow up time for all patients was 36 months (range 3 -54 months. The overall treatment time (OTT ranged from 52 to 69 days (median 58 days. The 3 year disease free survival rate was 81.8%, 70.7%, 40.08%, and 11.76% for stages I, II, III, and IV, respectively. There were 91 (26.6% cases with local residual diseases, 27(7.9% developed distant metastasis, and 18(5.26% pts had local recurrence. Discussion: The results of this study suggest that radical radiotherapy with HDR brachytherapy was appropriate for the treatment of early staged cancer of uterine cervix. For locally advanced cancer of cervix addition of concurrent chemotherapy, higher radiation doses, reduction of overall treatment time to less than 8 weeks, and use of latest radiotherapy techniques such as IMRT is recommended to improve the results.

  5. Filling the gap in central shielding: three-dimensional analysis of the EQD2 dose in radiotherapy for cervical cancer with the central shielding technique

    OpenAIRE

    Tamaki, Tomoaki; Ohno, Tatsuya; NODA, SHIN-EI; Kato, Shingo; Nakano, Takashi

    2015-01-01

    This study aimed to provide accurate dose distribution profiles of radiotherapy for cervical cancer when treated with the central shielding technique by analysing the composite 3D EQD2 dose distribution of external beam radiotherapy (EBRT) plus intracavitary brachytherapy (ICBT). On a phantom, four patterns of the combinations of whole pelvis irradiation (WP) (4 fields), pelvis irradiation with central shielding technique (CS) [anterior–posterior/posterior–anterior (AP-PA fields), shielding w...

  6. Combined external beam and intraluminal radiotherapy for irresectable Klatskin tumors

    Energy Technology Data Exchange (ETDEWEB)

    Schleicher, U.M. [Klinik fuer Strahlentherapie, Technische Hochschule Aachen (Germany); Staatz, G. [Klinik fuer Radiologische Diagnostik, Technische Hochschule Aachen (Germany); Alzen, G. [Klinik fuer Radiologische Diagnostik, Technische Hochschule Aachen (Germany); Abt. Kinderradiologie, Giessen Univ. (Germany); Andreopoulos, D. [Klinik fuer Strahlentherapie, Technische Hochschule Aachen (Germany); BOC Oncology Centre, Nikosia (Cyprus)

    2002-12-01

    Background: In most cases of proximal cholangiocarcinoma, curative surgery is not possible. Radiotherapy can be used for palliative treatment. We report our experience with combined external beam and intraluminal radiotherapy of advanced Klatskin's tumors. Patients and Methods: 30 patients were treated for extrahepatic proximal bile duct cancer. Our schedule consisted for external beam radiotherapy (median dose 30 Gy) and a high-dose-rate brachytherapy boost (median dose 40 Gy) delivered in four or five fractions, which could be applied completely in twelve of our patients. 15 patients in the brachytherapy and nine patients in the non-brachytherapy group received additional low-dose chemotherapy with 5-fluorouracil. Results: The brachytherapy boost dose improved the effect of external beam radiotherapy by increasing survival from a median of 3.9 months in the non-brachytherapy group to 9.1 months in the brachytherapy group. The effect was obvious in patients receiving a brachytherapy dose above 30 Gy, and in those without jaundice at the beginning of radiotherapy (p<0.05). Conclusions: The poor prognosis in patients with advanced Klatskin's tumors may be improved by combination therapy, with the role of brachytherapy and chemotherapy still to be defined. Our results suggest that patients without jaundice should be offered brachytherapy, and that a full dose of more than 30 Gy should be applied. (orig.) [German] Hintergrund: Bei den meisten Patienten mit proximalen Cholangiokarzinomen ist eine kurative Operation nicht mehr moeglich. Im Rahmen der Palliativbehandlung kann die Strahlentherapie eingesetzt werden. Wir berichten ueber unsere Erfahrungen mit der Kombination aus perkutaner und intraluminaler Strahlentherapie fortgeschrittener Klatskin-Tumoren. Patienten und Methode: 30 Patienten wurden wegen extrahepatischer proximaler Gallengangskarzinome behandelt. Unser Therapieschema umfasste eine perkutane Strahlentherapie (mediane Dosis: 30 Gy) sowie einen

  7. Does obesity hinder radiotherapy in endometrial cancer patients? The implementation of new techniques in adjuvant radiotherapy – focus on obese patients

    Directory of Open Access Journals (Sweden)

    Małgorzata Moszyńska-Zielińska

    2014-05-01

    Full Text Available The increasing incidence of obesity in Poland and its relation to endometrioid endometrial cancer (EEC is resulting in the increasing necessity of treating obese women. Treatment of an overweight patient with EEC may impede not only the surgical procedures but also radiotherapy, especially external beam radiotherapy (EBRT. The problems arise both during treatment planning and when delivering each fraction due to the difficulty of positioning such a patient – it implies the danger of underdosing targets and overdosing organs at risk. Willingness to use dynamic techniques in radiation oncology has increased for patients with EEC, even those who are obese. During EBRT careful daily verification is necessary for both safety and treatment accuracy. The most accurate method of verification is cone beam computed tomography (CBCT with soft tissue assessment, although it is time consuming and often requires a radiation oncologist. In order to improve the quality of such treatment, the authors present the practical aspects of planning and treatment itself by means of dynamic techniques in EBRT. The authors indicate the advantages and disadvantages of different types of on-board imaging (OBI verification images. Considering the scanty amount of literature in this field, it is necessary to conduct further research in order to highlight proper planning and treatment of obese endometrial cancer patients. The review of the literature shows that all centres that wish to use EBRT for gynaecological tumours should develop their own protocols on qualification, planning the treatment and methods of verifying the patients’ positioning.

  8. Performance of EPI diodes as dosimeters for photon beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Thais C. dos; Bizetto, Cesar A., E-mail: ccbueno@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Neves-Junior, Wellington F.P.; Haddad, Cecilia M.K. [Hospital Sirio Libanes (HSL), Sao Paulo, SP (Brazil); Goncalves, Josemary A.C.; Bueno, Carmen C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Pontificia Universidade Catolica de Sao Paulo (PUC-SP), SP (Brazil)

    2011-07-01

    In this work we present the preliminary results about the performance of an epitaxial (EPI) diode as on-line dosimeter for photon beam radiotherapy. The diode used was processed at University of Hamburg on n-type 75 {mu}m thick epitaxial silicon layer grown on a highly doped n-type 300 {mu}m thick Czochralski (Cz) silicon substrate. The measurements were performed with a diode which not received any type of pre-dose. In order to use this device as a dosimeter, it was enclosed in a black polymethylmethacrylate (PMMA) probe. The diode was connected to an electrometer Keithley 6517B in the photovoltaic mode. During all measurements, the diode was held between PMMA plates, placed at 10.0 cm depth and centered in a radiation field of 10 x 10 cm{sup 2}, with the source-to-surface distance (SSD) kept at 100 cm. The short-term repeatability was measured with photon beams of 6 and 18 MV energy by registering five consecutive current signals for the same radiation dose. The current signals induced showed good instantaneous repeatability of the diode, characterized by a smallest coefficient of variation (CV) of 0.21%. Furthermore, the dose-response curves of the diode were quite linear with the highest charge sensitivity achieved of 5.0 {mu}C/Gy. It worth noting that still remains to be investigated the pre-dose influence on epitaxial silicon diode response in radiotherapy photon beam dosimetry, the long term stability and the radiation hardness of these diodes for absorbed doses higher than that investigated in this work. All these studies are under way. (author)

  9. Status of Radiotherapy in Kenya: The Milestones and Challenges

    International Nuclear Information System (INIS)

    According to Gobacan 2012, seventy eight (78) Kenyans die daily of cancer related complications. Ratiotherapy is the treatment of cancer using high energy radiation targeting the tumour cells. The three main modalities used in treatment are radiotherapy, chemotherapy and surgery. More than 50% of cases are treated using radiotherapy. Radiotherapy is divided into two brad categoeis, namely external beam radiotherapy (EBRT) or teletherapy and internal radiotherapy (Brachytherapy). In Kenya, the machines available for EBRT are Cobalt-60 and linear accelerators. Co-60 source emits gamma-ray with energy of 1.25 MV while linear accelerators available locally emit photons (x-rays) and electrons ranging between 6 to 8MV. Until 2010, there was only one (public) radiotherapy facility using the co-60. Currently, four private facilities using linear accelerations have joined the fray. Two more public institutions are at different stages of putting up radiotherapy facilities. Owing to the high energy range, a lot of radiation safety considerations are made prior to installation, during acceptance testing and commissioning and during the operation. These include, but not limited to shielding integrity checks, Dosimetry checks, mechanical checks and emergency procedures check. In view of these, a lot of capacity building still needs to be done in term of skilled staff development as well as equipment

  10. Quality Assesment Of Photon And Electron Beams From Siemens PRIMUS Radiotherapy Accelerator

    International Nuclear Information System (INIS)

    There are two types of radiation from SIEMENS Primus Radiotherapy Accelerator at the National Cancer Hospital (K Hospital): electron and photon beams. Electron beams with four different energies of 6; 9; 12 and 15 MeV. Photon beams with two different energies: 6 MV and 15 MV. The symmetry as well as flatness of profiles created by all these beams are very important factors using in clinical practice. This report presents the method using water phantom to define absorbed dose distribution in medium of all beams. This is an effective and accurate method to define quality of radiation beams with different field sizes using in radiotherapy. (author)

  11. The use of beam code in external radiotherapy; Utilisation du code beam en radiotherapie externe

    Energy Technology Data Exchange (ETDEWEB)

    Guillerminet, C.; Gschwind, R.; Makovicka, L. [CREST - UMR 6000 CNRS, 25 - Montbeliard (France)

    2003-07-01

    This code, in constant evolution, has several assets because it allows in one hand to better characterize the beams at the energy and angular level of accelerators at medical use; these data being accessible only by simulation and on the other hand to establish a three dimensional dose calculation fro any phantom. The limit factors are the calculation time, the size of voxels need important dimension tables for the data storage, and the compatibility between the code and the different images formats. (N.C.)

  12. Issues in respiratory motion compensation during external-beam radiotherapy

    International Nuclear Information System (INIS)

    Purpose: To investigate how respiration influences the motion of lung and pancreas tumors and to relate the observations to treatment procedures intended to improve dose alignment by predicting the moving tumor's position from external breathing indicators. Methods and materials: Breathing characteristics for five healthy subjects were observed by optically tracking the displacement of the chest and abdomen, and by measuring tidal air volume with a spirometer. Fluoroscopic imaging of five radiotherapy patients detected the motion of lung and pancreas tumors synchronously with external breathing indicators. Results: The external and fluoroscopic data showed a wide range of behavior in the normal breathing pattern and its effects on the position of lung and pancreas tumors. This included transient phase shifts between two different external measures of breathing that diminished to zero over a period of minutes, modulated phase shifts between tumor and chest wall motion, and other complex phenomena. Conclusions: Respiratory compensation strategies that infer tumor position from external breathing signals, including methods of beam gating and dynamic beam tracking, require three-dimensional knowledge of the tumor's motion trajectory as well as the ability to detect and adapt to transient and continuously changing characteristics of respiratory motion during treatment

  13. Intraoperative avidination for radionuclide treatment as a radiotherapy boost in breast cancer: results of a phase II study with 90Y-labeled biotin

    International Nuclear Information System (INIS)

    External beam radiotherapy (EBRT) after conservative surgery for early breast cancer requires 5-7 weeks. For elderly patients and those distant from an RT center, attending for EBRT may be difficult or impossible. We investigated local toxicity, cosmetic outcomes, and quality of life in a new breast irradiation technique - intraoperative avidination for radionuclide therapy (IART) - in which avidin is administered to the tumor bed and 90Y-labelled biotin later administered intravenously to bind the avidin and provide irradiation. Reduced duration EBRT (40 Gy) is given subsequently. After surgery, 50 (ten patients), 100 (15 patients) or 150 mg (ten patients) of avidin was injected into the tumor bed. After 12-24 h, 3.7 GBq 90Y-biotin (beta source for therapeutic effect) plus 185 MBq 111In-biotin (gamma source for imaging and dosimetry) was infused slowly. Whole-body scintigraphy and SPECT/CT images were taken for up to 30 h. Shortened EBRT started 4 weeks later. Local toxicity was assessed by RTOG scale; quality of life was assessed by EORTC QOL-30. Of 35 patients recruited (mean age 63 years; range 42-74) 32 received IART plus EBRT. 100 mg avidin provided 19.5 ± 4.0 Gy to the tumor bed and was considered the optimum dose. No side-effects of avidin or 90Y-biotin occurred, with no hematological or local toxicity. Local G3 toxicity occurred in 3/32 patients during EBRT. IART plus EBRT was well accepted, with good cosmetic outcomes and maintained quality of life. IART plus reduced EBRT can accelerate irradiation after conservative breast surgery. (orig.)

  14. Intraoperative avidination for radionuclide treatment as a radiotherapy boost in breast cancer: results of a phase II study with {sup 90}Y-labeled biotin

    Energy Technology Data Exchange (ETDEWEB)

    Paganelli, Giovanni; De Cicco, Concetta; Carbone, Giuseppe; Pacifici, Monica [European Institute of Oncology, Division of Nuclear Medicine, Milan (Italy); Ferrari, Mahila E.; Cremonesi, Marta; Di Dia, Amalia [European Institute of Oncology, Division of Medical Physics, Milan (Italy); Pagani, Gianmatteo; Galimberti, Viviana; Luini, Alberto [European Institute of Oncology, Division of Senology, Milan (Italy); Leonardi, Maria Cristina; Ferrari, Annamaria; Orecchia, Roberto [European Institute of Oncology, Division of Radiotherapy, Milan (Italy); De Santis, Rita [Sigma-Tau SpA R and D, Rome (Italy); Zurrida, Stefano [European Institute of Oncology, Division of Senology, Milan (Italy); University of Milan School of Medicine, Milan (Italy); Veronesi, Umberto [European Institute of Oncology, Scientific Director, Milan (Italy)

    2010-02-15

    External beam radiotherapy (EBRT) after conservative surgery for early breast cancer requires 5-7 weeks. For elderly patients and those distant from an RT center, attending for EBRT may be difficult or impossible. We investigated local toxicity, cosmetic outcomes, and quality of life in a new breast irradiation technique - intraoperative avidination for radionuclide therapy (IART) - in which avidin is administered to the tumor bed and {sup 90}Y-labelled biotin later administered intravenously to bind the avidin and provide irradiation. Reduced duration EBRT (40 Gy) is given subsequently. After surgery, 50 (ten patients), 100 (15 patients) or 150 mg (ten patients) of avidin was injected into the tumor bed. After 12-24 h, 3.7 GBq {sup 90}Y-biotin (beta source for therapeutic effect) plus 185 MBq {sup 111}In-biotin (gamma source for imaging and dosimetry) was infused slowly. Whole-body scintigraphy and SPECT/CT images were taken for up to 30 h. Shortened EBRT started 4 weeks later. Local toxicity was assessed by RTOG scale; quality of life was assessed by EORTC QOL-30. Of 35 patients recruited (mean age 63 years; range 42-74) 32 received IART plus EBRT. 100 mg avidin provided 19.5 {+-} 4.0 Gy to the tumor bed and was considered the optimum dose. No side-effects of avidin or {sup 90}Y-biotin occurred, with no hematological or local toxicity. Local G3 toxicity occurred in 3/32 patients during EBRT. IART plus EBRT was well accepted, with good cosmetic outcomes and maintained quality of life. IART plus reduced EBRT can accelerate irradiation after conservative breast surgery. (orig.)

  15. Analysis of late toxicity associated with external beam radiation therapy for prostate cancer with uniform setting of classical 4-field 70 Gy in 35 fractions: a survey study by the Osaka Urological Tumor Radiotherapy Study Group

    OpenAIRE

    Yoshioka, Yasuo; Suzuki, Osamu; Nishimura, Kazuo; Inoue, Hitoshi; Hara, Tsuneo; Yoshida, Ken; Imai, Atsushi; Tsujimura, Akira; Nonomura, Norio; Ogawa, Kazuhiko

    2012-01-01

    We aimed to analyse late toxicity associated with external beam radiation therapy (EBRT) for prostate cancer using uniform dose-fractionation and beam arrangement, with the focus on the effect of 3D (CT) simulation and portal field size. We collected data concerning patients with localized prostate adenocarcinoma who had been treated with EBRT at five institutions in Osaka, Japan, between 1998 and 2006. All had been treated with 70 Gy in 35 fractions, using the classical 4-field technique wit...

  16. Residual tumour volumes and grey zones after external beam radiotherapy (with or without chemotherapy) in cervical cancer patients. A low-field MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, M.P.; Mansmann, B.; Federico, M.; Georg, P.; Fidarova, E. [General Hospital of Vienna (Austria). Dept. of Radiotherapy; Dimopoulous, J.C.A. [Metropolitan Hospital, Athens (Greece). Dept. of Radiation Oncology; Doerr, W. [General Hospital of Vienna (Austria). Dept. of Radiotherapy; Technische Univ. Dresden (Germany). Dept. of Radiotherapy and Radiation Oncology; Medical University of Vienna (Austria). Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology; Poetter, R. [General Hospital of Vienna (Austria). Dept. of Radiotherapy; Medical University of Vienna (Austria). Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology

    2013-03-15

    Background: Grey zones, which are defined as tissue with intermediate signal intensity in the area of primary hyperintense tumour extension, can be seen during radiation with or without chemotherapy on the T2-weighted MRI in patients with cervical cancer. The purpose of this study was to systematically measure the tumour volume at the time of diagnosis and the residual tumour volume at the time of brachytherapy without and with consideration of the grey zones and to estimate tumour regression during external beam radiotherapy (EBRT). Material and methods: T2-weighted MRI datasets of 175 patients with locally advanced cervical cancer (FIGO stage IB-IVA), who underwent combined external beam radiotherapy and brachytherapy with or without concomitant chemotherapy were available for this study. The gross tumour volume at the time of diagnosis (GTV{sub init}) and at the time of first brachytherapy without (GTV{sub res}) and with (GTV{sub res} + GZ) consideration of grey zones were measured for each patient. A descriptive statistical analysis was performed and tumour regression rates without (R) and with consideration of grey zones (R{sub GZ}) were calculated. Further, the role of prognostic factors on GTV{sub init}, GTV{sub res}, GTV{sub res} + GZ and tumour regression rates was investigated. Results: The median GTV{sub init}, GTV{sub res}, GTV{sub res} + GZ in all patients were 44.4 cm{sup 3}, 8.2 cm{sup 3}, 20.3 cm{sup 3}, respectively. The median R was 78.5% and the median R{sub GZ} was 50.1%. The histology and FIGO staging showed a significant impact on GTV{sub init}, GTV{sub res} and GTV{sub res} + GZ. Conclusion: Grey zones represent a substantial proportion of the residual tumour volume at the time of brachytherapy. Differentiation of high signal intensity mass and surrounding intermediate signal intensity grey zones may be reasonable. (orig.)

  17. Residual tumour volumes and grey zones after external beam radiotherapy (with or without chemotherapy) in cervical cancer patients. A low-field MRI study

    International Nuclear Information System (INIS)

    Background: Grey zones, which are defined as tissue with intermediate signal intensity in the area of primary hyperintense tumour extension, can be seen during radiation with or without chemotherapy on the T2-weighted MRI in patients with cervical cancer. The purpose of this study was to systematically measure the tumour volume at the time of diagnosis and the residual tumour volume at the time of brachytherapy without and with consideration of the grey zones and to estimate tumour regression during external beam radiotherapy (EBRT). Material and methods: T2-weighted MRI datasets of 175 patients with locally advanced cervical cancer (FIGO stage IB-IVA), who underwent combined external beam radiotherapy and brachytherapy with or without concomitant chemotherapy were available for this study. The gross tumour volume at the time of diagnosis (GTVinit) and at the time of first brachytherapy without (GTVres) and with (GTVres + GZ) consideration of grey zones were measured for each patient. A descriptive statistical analysis was performed and tumour regression rates without (R) and with consideration of grey zones (RGZ) were calculated. Further, the role of prognostic factors on GTVinit, GTVres, GTVres + GZ and tumour regression rates was investigated. Results: The median GTVinit, GTVres, GTVres + GZ in all patients were 44.4 cm3, 8.2 cm3, 20.3 cm3, respectively. The median R was 78.5% and the median RGZ was 50.1%. The histology and FIGO staging showed a significant impact on GTVinit, GTVres and GTVres + GZ. Conclusion: Grey zones represent a substantial proportion of the residual tumour volume at the time of brachytherapy. Differentiation of high signal intensity mass and surrounding intermediate signal intensity grey zones may be reasonable. (orig.)

  18. Salivary Gland. Photon beam and particle radiotherapy: Present and future.

    Science.gov (United States)

    Orlandi, Ester; Iacovelli, Nicola Alessandro; Bonora, Maria; Cavallo, Anna; Fossati, Piero

    2016-09-01

    Salivary gland cancers (SGCs) are rare diseases and their treatment depends upon histology, stage and site of origin. Radical surgery is the mainstay of treatment but radiotherapy (RT) plays a key role in both the postoperative and the inoperable setting, as well as in recurrent disease. In the absence of prospective randomized trials, a wide retrospective literature suggests postoperative RT (PORT) in patients with high risk pathological features. SGCs, and adenoid cystic carcinoma (ACC) in particular, are known to be radio-resistant tumors and should therefore respond well to particle beam therapy. Recently, excellent outcome has been reported with radical carbon ion RT (CIRT) in particular for ACC. Both modern photon- and hadron-based treatments are effective and are characterized by a favourable toxicity profile. But it is not clear whether one modality is superior to the other for disease control, due to the differences in patients' selection, techniques, fractionation schedules and outcome measurements among clinical experiences. In this paper, we review the role of photon and particle RT for malignant SGCs, discussing the difference between modalities in terms of biological and technical characteristics. RT dose and target volumes for different histologies (ACC versus non-ACC) have also been taken into consideration. PMID:27394087

  19. The relationship between the biochemical control outcomes and the quality of planning of high-dose rate brachytherapy as a boost to external beam radiotherapy for locally and locally advanced prostate cancer using the RTOG-ASTRO Phoenix definition

    Directory of Open Access Journals (Sweden)

    Antonio Cassio Assis Pellizzon, João Salvajoli, Paulo Novaes, Maria Maia, Ricardo Fogaroli, Doglas Gides, Rodrigues Horriot

    2008-01-01

    Full Text Available Purpose: To evaluated prognostic factors and impact of the quality of planning of high dose rate brachytherapy (HDR-BT for patients with local or locally advanced prostate cancer treated with external beam radiotherapy (EBRT and HDR-BT. Methods and Materials: Between 1997 and 2005, 209 patients with biopsy proven prostate adenocarcinoma were treated with localized EBRT and HDR-BT at the Department of Radiation-Oncology, Hospital A. C. Camargo, Sao Paulo, Brazil. Patient's age, Gleason score (GS, clinical stage (CS, initial PSA (iPSA, risk group for biochemical failure (GR, doses of EBRT and HDR-BT, use of three-dimensional planning for HDR-BT (3DHDR and the Biological Effective Dose (BED were evaluated as prognostic factors for biochemical control (bC. Results: Median age and median follow-up time were 68 and 5.3 years, respectively. Median EBRT and HDR-BT doses were 45 Gy and 20 Gy. The crude bC at 3.3 year was 94.2%. For the Low, intermediate and high risk patients the bC rates at 3.3 years were 91.5%, 90.2% and 88.5%, respectively. Overall survival (OS and disease specific survival rates at 3.3 years were 97.8% and 98.4%, respectively. On univariate analysis the prognostic factors related bC were GR (p= 0.040, GS ≤ 6 (p= 0.002, total dose of HDR-BT ≥ 20 Gy (p< 0.001, 3DHDR (p< 0.001, BED-HDR ≥ 99 Gy1.5 (p<0.001 and BED-TT ≥ 185 (p<0.001. On multivariate analysis the statistical significant predictive factors related to bC were RG (p< 0.001, HDR-BT ≥ 20 Gy (p=0.008 and 3DHDR (p<0.001. Conclusions: we observed that the bC rates correlates with the generally accepted risk factors described in the literature. Dose escalation, evaluated through the BED, and the quality of planning of HDR-BT are also important predictive factors when treating prostate cancer.

  20. Patient-reported lower urinary tract symptoms, urinary incontinence, and quality of life after external beam radiotherapy for localized prostate cancer - 15 years' follow-up. A comparison with age-matched controls

    Energy Technology Data Exchange (ETDEWEB)

    Fransson, Per (Dept. of Radiation Sciences, Oncology, Umeaa Univ., Umeaa (Sweden))

    2008-06-15

    Background. To prospectively examine the urinary toxicity and quality of life (QOL) in patients 15 years after external beam radiotherapy (EBRT) for localized prostate cancer (LPC) and compare the outcomes with results for age-matched controls. Material and methods. Urinary symptoms were assessed using the symptom-specific Prostate Cancer Symptom Scale (PCSS) questionnaire, and QOL was assessed with the European Organization for Research and Treatment of Cancer (EORTC)'s Quality of Life Questionnaire (QLQ-C30). Both questionnaires were sent to the surviving 41 patients (25%) and the PCSS questionnaire was sent to 69 age-matched controls for comparison. Results. The response rate was 71% in the patient group and 59% in the control group. Two patients and four controls were excluded due to other cancer diagnoses, resulting in a total of 27 patients and 37 controls for inclusion in the analyses. The mean age in both groups was 78 years. In the patient group, incontinence had increased between the 8-year (mean=0.6) and the 15-year follow-up (mean=2.1; p=0.038). No other differences in urinary problems were seen between these two follow-ups. Increased incontinence, stress incontinence, and pain while urinating were reported by the patients in comparison with the controls at 15 years. Role function was worse in the patient group (mean=67.3) compared with the controls (mean=82.4; p=0.046). The patients also reported more appetite loss, diarrhea, nausea/vomiting, and pain than the controls. Conclusion. EBRT for LPC has divergent effects on urinary symptoms and QOL in comparison with age-matched controls. In our patient population, urinary incontinence increased between 8 and 15 years of follow-up. Otherwise, no differences in urinary symptoms were seen between 4 and 15 years. Incontinence, stress incontinence, and pain while urinating were increased after EBRT in comparison with the controls. Conventional EBRT did not result in a major deterioration in QOL 15 years

  1. Dosimetric Comparing between Protons Beam and Photons Beam 
for Lung Cancer Radiotherapy: A Meta-analysis

    Directory of Open Access Journals (Sweden)

    Guangwei TIAN

    2013-05-01

    Full Text Available Background and objective The clinical evidences are not sufficient on the proton beam therapy of lung cancer for lacking of the RCTs on the comparing the proton with the photon beam in lung cancer radiotherapy. The aim of this study is to evaluate the dosimetry superiority of the proton beam and provide more valuable evidences to the clinical researches. Methods Clinical trails of dosimetric comparing between protons beam and photons beam for lung cancer radiotherapy were obtained from the Cochrane library, Pubmed, EMbase, CBM, CNKI, VIP, and Wan Fang databases. The data included in the study were evaluated and analyzed using the Cochrane Collaboration's RevMan 5.2 software. Results Six trails were included. Compared to photon therapy (three-dimensional conformal photon radiotherapy, 3D-CRT, the proton therapy had a significantly lower total lung Dmean (MD=-4.15, 95%CI: -5.56--2.74, P<0.001 and V20, V10, V5 (MD=-10.92, 95%CI: -13.23--8.62, P<0.001; The V20, V10, V5 significantly decreased in proton therapy group. Compared to photon therapy (intensity-modulated photon radiotherapy, IMRT, V20, V10, V5 were also significantly lowered in proton therapy group (MD=-3.70, 95%CI: -5.31--2.10, P<0.001; MD=-8.86, 95%CI: -10.74--6.98, P<0.001; MD=-20.13, 95%CI: -27.11--13.14, P<0.001; The esophagus Dmean was not lowered, while the heart Dmean decreased in proton therapy group. Conclusion Comparing to photon beam radiotherapy (3D-CRT and IMRT, proton beam therapy is advantageous in dosimetry of the lung cancer radiotherapy and recommended for clinical applying.

  2. Radiotherapy for 71 patients with tonsillar carcinoma

    International Nuclear Information System (INIS)

    Objective: To evaluate the therapeutic outcome and determine the prognosticators of tonsillar carcinoma treated by different approaches. Methods: A retrospective study was done on 71 tonsillar carcinoma patients treated from August 1971 to October 1995 by three different ways of radiotherapy. All were pathologically proved. Fifteen patients received external bean therapy plus intracavitary brachytherapy (EBRT + BRT), 39 patients were treated by EBRT only (EBRT) and the other 17 patients underwent FBRT plus chemotherapy (EBTR + CHEMO). Results: The local control rates of EBRT + BRT, EBRT and EBRT + chemo were 82.1%, 68.4% and 64.2%. There was significant difference between EBRT + BRT and the other two groups (x2=4.65, P=0.030; x2=5.65, P=0.018). The 3-, 5- and 10- year survival rates of EBRT + BRT, EBRT and EBRT + CHEMO were 76.3%, 53.2%, 31.2%; 74.0%, 45.2%, 33.5% and 75.2%, 47.1%, 25.3%. All these survival rates showed no statistical significance. (P > 0.05). Conclusion: Brachytherapy, when used to increase the dose effect, may enhance the local effect without any change in the overall survival

  3. Radiotherapy combined with hormonal therapy in prostate cancer: the state of the art

    Directory of Open Access Journals (Sweden)

    Piotr Milecki

    2010-10-01

    Full Text Available Piotr Milecki1,2, Piotr Martenka1, Andrzej Antczak3, Zbigniew Kwias31Department of Radiotherapy, Greater Poland Cancer Center, Poznan, Poland; 2Department of Electroradiology, Medical University, Poznan, Poland; 3Chair of Urology, Medical University, Poznan, PolandAbstract: Androgen-deprivation therapy (ADT is used routinely in combination with definitive external beam radiation therapy (EBRT in patients with high-risk clinically localized or locally advanced disease. The combined treatment (ADT–EBRT also seems to play a significant role in improving treatment results in the intermediate-risk group of prostate cancer patients. On the other hand, there is a growing body of evidence that treatment with ADT can be associated with serious and lifelong adverse events including osteoporosis, cardiovascular disease, diabetes, and many others. Almost all ADT adverse events are time dependant and tend to increase in severity with prolongation of hormonal manipulation. Therefore, it is crucial to clearly state the optimal schedule for ADT in combination with EBRT, that maintaining the positive effect on treatment efficacy would keep the adverse events risk at reasonable level. To achieve this goal, treatment schedule may have to be highly individualized on the basis of the patient-specific potential vulnerability to adverse events. In this study, the concise and evidence-based review of current literature concerning the general rationales for combining radiotherapy and hormonal therapy, its mechanism, treatment results, and toxicity profile is presented.Keywords: prostate cancer, radiotherapy, androgen deprivation, combined treatment

  4. One-dimensional field analyzer of medical proton beam in radiotherapy

    International Nuclear Information System (INIS)

    A Medical-Technical Complex for hadron radiotherapy of cancer patients based on the 660 MeV proton Phasotron has been constructed and put into operation at JINR. Upgrading of methods, hardware and software for radiotherapy is one of the main tasks for further development of the Facility. This article concerns one of the fields of this work: that is the development of equipment for conformal proton beam therapy and dynamic irradiation of deep lying target - the construction of a device for measurement of proton beam depth-dose curve in a treatment room

  5. Intraoperative Radiotherapy for Pancreatic Cancer: 30-Year Experience in a Single Institution in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Jingu, Keiichi, E-mail: kjingu-jr@rad.med.tohoku.ac.jp [Department of Radiation Oncology, Tohoku University School of Medicine, Sendai (Japan); Tanabe, Takaya [Department of Radiation Oncology, Tohoku University School of Medicine, Sendai (Japan); Nemoto, Kenji [Department of Radiation Oncology, Yamagata University School of Medicine, Yamagata (Japan); Ariga, Hisanori; Umezawa, Rei; Ogawa, Yoshihiro; Takeda, Ken; Koto, Masashi; Sugawara, Toshiyuki; Kubozono, Masaki; Shimizu, Eiji; Abe, Keiko; Yamada, Shogo [Department of Radiation Oncology, Tohoku University School of Medicine, Sendai (Japan)

    2012-07-15

    Purpose: To analyze retrospectively the results of intraoperative radiotherapy (IORT) with or without external beam radiotherapy ({+-} EBRT) for localized pancreatic cancer in the past three decades and to analyze prognostic factors by multivariate analysis. Methods and Materials: Records for 322 patients with pancreatic cancer treated by IORT {+-} EBRT in Tohoku University Hospital between 1980 and 2009 were reviewed. One hundred ninety-two patients who had no distant organ metastases or dissemination at the time of laparotomy were enrolled in the present study. Results: Eighty-three patients underwent gross total resection (R0: 48 patients, R1: 35 patients), and 109 patients underwent only biopsy or palliative resection. Fifty-five patients underwent adjuvant EBRT, and 124 underwent adjuvant chemotherapy. The median doses of IORT and EBRT were 25 and 40 Gy, respectively. The median follow-up period was 37.5 months. At the time of the analysis, 166 patients had disease recurrence, and 35 patients had local failure. The 2-year local control (LC) and overall survival (OS) rates were 71.0% and 16.9%, respectively. Comparison of the results for each decade showed that OS was significantly improved decade by decade (2-year: 25.0% vs. 18.8% vs. 4.2%, p < 0.001). Multivariate analysis showed that degree of resection (R0-1 vs. R2, hazard ratio = 1.97, p = 0.001) and adjuvant chemotherapy (yes vs. no, hazard ratio = 1.54, p = 0.028) had significant impacts on OS. Late gastrointestinal morbidity of Common Terminology Criteria for Adverse Events version 3.0 grade 4 or 5 was observed in four patients. Conclusion: Excellent local control for pancreatic cancer with few cases of severe late toxicity was achieved by using IORT. OS of patients with pancreatic cancer treated by IORT {+-} EBRT improved significantly decade by decade. Multivariate analysis showed that degree of resection and adjuvant chemotherapy had significant impacts on OS.

  6. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

    Science.gov (United States)

    Christensen, A. N.; Rydhög, J. S.; Søndergaard, R. V.; Andresen, T. L.; Holm, S.; Munck Af Rosenschöld, P.; Conradsen, K.; Jølck, R. I.

    2016-05-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively.Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The

  7. Factors determining acute normal tissue reactions during postoperative radiotherapy in endometrial cancer: analysis of 317 consecutive cases

    International Nuclear Information System (INIS)

    Background and purpose: Acute radiotherapy reactions are commonly underestimated and under-reported in the literature. Our aim was to evaluate the incidence and risk factors for acute reactions during postoperative radiotherapy in endometrial cancer patients. Material and methods: Performed was detailed retrospective analysis of 317 endometrial cancer patients given postoperative radiotherapy. Two hundred forty seven patients (78%) received both intracavitary (BRT) and external beam irradiation (EBRT), 49 patients (15%) received only BRT and 21 patients (7%) - only EBRT. BRT included radium (Ra) or cesium (Cs). The mean total dose at 0.5 cm for Ra and Cs was 50.5±10.3 Gy and 48.4±15.0 Gy, respectively, and the mean dose rate - 0.47±0.06 Gy/h and 1.42±0.41 Gy/h, respectively. Mean EBRT dose in the ICRU reference point was 49.0±3.7 Gy given in fractions of 1.54-2.49 Gy (mean 2.0±0.17 Gy). Radiotherapy and Oncology Group classification system was employed to score acute reactions. The impact of patient- and treatment-related factors on the risk of acute bowel and urinary bladder reactions was assessed with uni- and multivariate tests. Results: Acute radiotherapy reactions of any grade occurred in 265 patients (84%) including bowel complications in 66% and urinary bladder complications in 36%. There were 21 severe (grade 3 or 4) reactions, all but one seen in the patients treated with combined EBRT and BRT. Higher total dose (P=0.024), higher EBRT dose (P=0.022) and higher age (P=0.026) were correlated with increased acute bowel toxicity in univariate analysis. Multivariate analysis showed that higher EBRT dose (P=0.015) and older age (P=0.016) were independently correlated with the risk of acute bowel events. Higher total dose (P=0.009), BRT dose (P=0.029), BRT dose rate (P=0.004), EBRT fraction size (P=0.007), the use of Cs BRT (P=0.001) and lower parity (P=0.041) were correlated with increased risk of acute bladder toxicity in univariate test. Multivariate

  8. IART® (Intra-Operative Avidination for Radionuclide Therapy) for accelerated radiotherapy in breast cancer patients. Technical aspects and preliminary results of a phase II study with 90Y-labelled biotin

    OpenAIRE

    Paganelli, G.; De Cicco, C; M. E. Ferrari; McVie, G.; Pagani, G; Leonardi, M C; Cremonesi, M.; Ferrari, A.; Pacifici, M.; Di Dia, A; Botta, F; De Santis, R; Galimberti, V.; Luini, A.; Orecchia, R.

    2010-01-01

    Background: Breast conserving surgery (BCS) plus external beam radiotherapy (EBRT) is considered the standard treatment for early breast cancer. We have investigated the possibility of irradiating the residual gland, using an innovative nuclear medicine approach named IART® (Intra-operative Avidination for Radionuclide Therapy). Aim: The objective of this study was to determine the optimal dose of avidin with a fixed activity (3.7 GBq) of 90Y-biotin, in order to provide a boost of 20 Gy, foll...

  9. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography.

    Science.gov (United States)

    Christensen, A N; Rydhög, J S; Søndergaard, R V; Andresen, T L; Holm, S; Munck Af Rosenschöld, P; Conradsen, K; Jølck, R I

    2016-06-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive (106)Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively. PMID:27174233

  10. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

    DEFF Research Database (Denmark)

    Christensen, Anders Nymark; Rydhög, J. S.; Søndergaard, Rikke Vicki;

    2016-01-01

    -nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive (106)Ag......Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver...

  11. Volumetric modulation arc radiotherapy with flattening filter-free beams compared with conventional beams for nasopharyngeal carcinoma: a feasibility study

    Institute of Scientific and Technical Information of China (English)

    Mingzan Zhuang; Tuodan Zhang; Zhijian Chen; Zhixiong Lin; Derui Li; Xun Peng; Qingchun Qiu

    2013-01-01

    There is increasing interest in the clinical use of flattening filter-free (FFF) beams.In this study,we aimed to investigate the dosimetric characteristics of volumetric modulated arc radiotherapy (VMAT) with FFF beams for nasopharyngeal carcinoma (NPC).Ten NPC patients were randomly selected to undergo a RapidArc plan with either FFF beams (RA-FFF) or conventional beams (RA-C).The doses to the planning target volumes (PTVs),organs at risk (OARs),and normal tissues were compared.The technical delivery parameters for RapidArc plans were also assessed to compare the characteristics of FFF and conventional beams.Both techniques delivered adequate doses to PTVs.For PTVs,RA-C delivered lower maximum and mean doses and improved conformity and homogeneity compared with RA-FFF.Both techniques provided similar maximum doses to the optic nerves and lenses.For the brain stem,spinal cord,larynx,parotid glands,oral cavity,and skin,RA-FFF showed significant dose increases compared to RA-C.The dose to normal tissue was lower in RA-FFF.The monitor units (MUs) were (536 ± 46) MU for RA-FFF and (501 ± 25) MU for RA-C.The treatment duration did not significantly differ between plans.Although both treatment plans could meet clinical needs,RA-C is dosimetrically superior to RA-FFF for NPC radiotherapy.

  12. Management of hilar bile duct carcinoma with high-dose radiotherapy and expandable metallic stent placement

    International Nuclear Information System (INIS)

    This article describes our experience with high-dose radiotherapy in combination with the placement of expandable metallic stents (EMS) in the management of hilar bile duct carcinoma. Between 1988 and 1999, 107 consecutive patients with hilar bile duct carcinoma were treated with EMS placement either alone or in combination with high-dose radiotherapy. External beam radiotherapy (EBRT) was indicated in 101 patients, and in 86 this was combined with intraluminal 192Ir irradiation (ILRT, 59-98 Gy) EMS were placed after the completion of radiotherapy. The 1-, 2-, 3-, and 5-year actuarial survival rates for the radiotherapy group were 66.4%, 23.4%, 15.6%, 7.8%, respectively, and the 1- and 2-year actuarial survival rates for the nonradiotherapy group were 66.4% and 0%, respectively. The placement of EMS was useful for the early establishment of an internal bile passage in radically irradiated patients and the 1-, 2-, 3-, and 5-year actuarial patency rates for the radiotherapy group were 56.3%, 45.3%, 35.2%, and 23.4%, respectively, and the 1- and 2-year actuarial patency rates for the non radiotherapy group were 50.0% and 0% respectively. High-dose radiotherapy, consisting of ILRT and EBRT, appears to be feasible in the management of hilar bile duct carcinoma, and it offers a survival advantage for patients no suited for surgical resection. The placement of EMS assists the internal bile flow and lengthens survival after high-dose radiotherapy. (author)

  13. External beam radiotherapy plus single-fraction high dose rate brachytherapy in the treatment of locally advanced prostate cancer

    International Nuclear Information System (INIS)

    Purpose: To evaluate the efficacy and toxicity of external beam radiation therapy (EBRT) plus high-dose-rate brachytherapy (HDRB) as a boost in patients (pts) with intermediate or high-risk prostate cancer. Methods and materials: From 2002 to July 2012, 377 pts with a diagnosis of intermediate or high-risk prostate cancer were treated with EBRT plus HDRB. Median patient age was 66 years (range, 41–86). Most patients (347 pts; 92%) were classified as high-risk (stage T2c–T3, or PSA > 20 ng/mL, or GS ⩾ 8), with 30 patients (8%) considered intermediate risk. All patients underwent EBRT at a prescribed dose of 60.0 Gy (range, 45–70 Gy) to the prostate and seminal vesicles. A total of 120 pts (31%) received a dose of 46 Gy (45–50 Gy) to the true pelvis. All pts received a single-fraction 9 Gy (9–15 Gy) HDR boost. Most patients (353; 94%) were prescribed complete androgen deprivation therapy (ADT). Overall survival (OS), cause-specific survival (CSS), and biochemical relapse-free survival (BRFS) rates were calculated. In the case of BRFS, patients with <26 months of follow-up (n = 106) were excluded to minimize the impact of ADT. Results: The median follow-up for the entire sample was 50 months (range, 12–126), with 5-year actuarial OS and CSS, respectively, of 88% (95% confidence interval [CI]: 84–92) and 98% (95% CI: 97–99). The 5-year BRFS was 91% (95% CI: 87–95) in the 271 pts with ⩾26 months (median, 60 months) of follow-up. Late toxicity included grade 2 and 3 gastrointestinal toxicity in 17 (4.6%) and 6 pts (1.6%), respectively, as well as grades 2 and 3 genitourinary toxicity in 46 (12.2%) and 3 pts (0.8%), respectively. Conclusion: These long-term outcomes confirm that EBRT plus a single-fraction HDRB boost provides good results in treatment-related toxicity and biochemical control. In addition to the excellent clinical results, this fractionation schedule reduces physician workload, treatment-related expenses, patient discomfort and risks

  14. Multimodality treatment for cerebral arteriovenous malformations. Complementary role of proton beam radiotherapy

    International Nuclear Information System (INIS)

    A total of 29 cerebral arteriovenous malformations (AVMs) treated at the University of Tsukuba with multimodality treatment including proton beam (PB) radiotherapy for cerebral AVMs between 2005 and 2011 were retrospectively evaluated. Eleven AVMs were classified as Spetzler-Martin grades I and II, 10 as grade III, and 8 as grades IV and V. For AVMs smaller than 2.5 cm and located on superficial and non-eloquent areas, surgical removal with/without embolization was offered as a first-line treatment. For some small AVMs located in deep or eloquent lesions, gamma knife (GK) radiosurgery was offered. Some AVMs were treated with only embolization. AVMs larger than 2.5 cm were embolized to achieve reduction in size, to enhance the safety of the surgery, and to render the AVM amenable to GK radiosurgery. For larger AVMs located in deep or eloquent areas, PB radiotherapy was offered with/without embolization. Immediately after the treatment, 24 patients exhibited no neurological worsening. Four patients had moderate disability, and 1 patient had severe disability. Three patients suffered brain damage after surgical resection, and 2 patients suffered embolization complications. However, no neurological worsening was observed after either GK radiosurgery or PB radiotherapy, but 3 patients treated by PB radiotherapy suffered delayed hemorrhage. Fractionated PB radiotherapy for cerebral AVMs seems to be useful for the treatment of large AVMs, but careful long-term follow up is required to establish the efficacy and safety. (author)

  15. Facilities for radiotherapy with ion beams status and worldwide developments

    CERN Document Server

    Wolf, B H

    1999-01-01

    Forty-five years after the first ion beam therapy in Berkeley around 25,000 cancer patients worldwide have been treated successfully. Ion accelerators, designed for nuclear research, delivered most of this treatment. The first hospital-based facility started operation in 1998 at Loma Linda California, the first for heavier ions at Chiba, Japan in 1994 and the first commercially delivered facilities started operation in 1998 at Kashiwa, Japan. In 2000, the Harvard Medical Centre, Boston, US, will commence operation and several new facilities are planned or under construction worldwide, although none in Australia. This paper will discuss the physical and biological advantages of ion beams over x-rays and electrons. In the treatment of cancer patients ion beam therapy is especially suited for localised tumours in radiation sensitive areas like skull or spine. Heavier ions are also effective in anoxic tumour cells (found around the normally oxygenated cell population). An additional advantage of the heavier carbo...

  16. A dose optimization method for electron radiotherapy using randomized aperture beams.

    Science.gov (United States)

    Engel, Konrad; Gauer, Tobias

    2009-09-01

    The present paper describes the entire optimization process of creating a radiotherapy treatment plan for advanced electron irradiation. Special emphasis is devoted to the selection of beam incidence angles and beam energies as well as to the choice of appropriate subfields generated by a refined version of intensity segmentation and a novel random aperture approach. The algorithms have been implemented in a stand-alone programme using dose calculations from a commercial treatment planning system. For this study, the treatment planning system Pinnacle from Philips has been used and connected to the optimization programme using an ASCII interface. Dose calculations in Pinnacle were performed by Monte Carlo simulations for a remote-controlled electron multileaf collimator (MLC) from Euromechanics. As a result, treatment plans for breast cancer patients could be significantly improved when using randomly generated aperture beams. The combination of beams generated through segmentation and randomization achieved the best results in terms of target coverage and sparing of critical organs. The treatment plans could be further improved by use of a field reduction treatment plans could be further improved by use of a field reduction algorithm. Without a relevant loss in dose distribution, the total number of MLC fields and monitor units could be reduced by up to 20%. In conclusion, using randomized aperture beams is a promising new approach in radiotherapy and exhibits potential for further improvements in dose optimization through a combination of randomized electron and photon aperture beams.

  17. Feasibility study on effect and stability of adaptive radiotherapy on kilovoltage cone beam CT:

    OpenAIRE

    Yadav, Poonam; Ramasubramanian, Velayudham; Paliwal, Bhudatt R.

    2011-01-01

    Background We have analyzed the stability of CT to density curve of kilovoltage cone-beam computerized tomography (kV CBCT) imaging modality over the period of six months. We also, investigated the viability of using image value to density table (IVDT) generated at different time, for adaptive radiotherapy treatment planning. The consequences of target volume change and the efficacy of kV CBCT for adaptive planning issues is investigated. Materials and methods. Standard electron density phant...

  18. Shading correction algorithm for improvement of cone-beam CT images in radiotherapy

    OpenAIRE

    Marchant, T. E.; Moore, C. J.; Rowbottom, C G; Mackay, R. I.; Williams, P.C.

    2008-01-01

    Cone-beam CT (CBCT) images have recently become an established modality for treatment verification in radiotherapy. However, identification of soft-tissue structures and the calculation of dose distributions based on CBCT images is often obstructed by image artefacts and poor consistency of density calibration. A robust method for voxel-by-voxel enhancement of CBCT images using a priori knowledge from the planning CT scan has been developed and implemented. CBCT scans were enhanced using a lo...

  19. The magic cube and the pixel ionization chamber: detectors for monitor and dosimetry of radiotherapy beams

    Science.gov (United States)

    Amerio, S.; Boriano, A.; Bourhaleb, F.; Cirio, R.; Donetti, M.; Garelli, E.; Giordanengo, S.; Madon, E.; Marchetto, F.; Nastasi, U.; Peroni, C.; Sanz Freire, C. J.; Sardo, A.; Trevisiol, E.

    2003-09-01

    Tumor therapy takes advantage of the energy deposition of radiation to concentrate high doses in the target while sparing healthy tissue. Elective pathologies for highly conformal radiotherapies such as photon Intensity Modulated Radiotherapy (IMRT) and radiotherapy with hadrons are head and neck, eye, prostate and in general all tumors that are either deep or located close to critical organs. In the world there are several centers that are using such techniques and a common problem that is being experienced is the verification of treatment plans and monitoring of the beam. We have designed and built two detectors that allow 2D and 3D measurements of dose and fluence of such beams. The detectors allow measurements on big surfaces, up to 25∗25 cm2. The active media are parallel plate, strip and pixel segmented ionization chambers with front-end Very Large Scale Integration (VLSI) readout and PC based data acquistion. The description of dosimeter, chamber and electronics will be given with results from beam tests and therapy plan verification.

  20. {sup 11}C-Choline PET/CT detects the site of relapse in the majority of prostate cancer patients showing biochemical recurrence after EBRT

    Energy Technology Data Exchange (ETDEWEB)

    Ceci, Francesco; Graziani, Tiziano; Lodi, Filippo; Fanti, Stefano [University of Bologna, Service of Nuclear Medicine, Policlinico S. Orsola Malpighi, Bologna (Italy); Castellucci, Paolo [University of Bologna, Service of Nuclear Medicine, Policlinico S. Orsola Malpighi, Bologna (Italy); Azienda Ospedaliero-Unversitaria di Bologna Policlinico Sant' Orsola-Malpighi, UO di Medicina Nucleare, PAD. 30, Bologna (Italy); Schiavina, Riccardo; Brunocilla, Eugenio; Martorana, Giuseppe [University of Bologna, Department of Urology, Policlinico S. Orsola Malpighi, Bologna (Italy); Mazzarotto, Renzo; Ntreta, Maria [University of Bologna, Service of Radiotherapy, Policlinico S. Orsola Malpighi, Bologna (Italy)

    2014-05-15

    The aim of this retrospective study was to evaluate the usefulness and the detection rate of {sup 11}C-choline PET/CT in a population of patients with prostate cancer (PC), exclusively treated with external beam radiotherapy (EBRT) as primary treatment, who showed biochemical relapse. We enrolled 140 patients showing a serum PSA level >2 ng/mL (mean 8.6 ng/mL, median 5 ng/mL, range 2 - 60 ng/mL). All patients had been treated with EBRT to the prostate gland and prostatic fossa with doses ranging from 70 to 76 Gy in low-risk patients (T1/T2 and/or serum PSA <10 ng/mL) and escalating to >76 Gy (range 76 - 81 Gy) in high-risk patients (T3/T4 and/or serum PSA >10 ng/mL). Of the 140 patients, 53 were receiving androgen deprivation therapy at the time of the scan. All positive {sup 11}C-choline PET/CT findings were validated by transrectal ultrasound-guided biopsy or at least 12 months of follow-up with contrast-enhanced CT, MR, bone scintigraphy or a repeated {sup 11}C-choline PET/CT scan. The relationships between the detection rate of {sup 11}C-choline PET/CT and the factors PSA level, PSA kinetics, Gleason score, age, time to relapse and SUVmax in patients with positive findings were analysed. {sup 11}C-Choline PET/CT detected the site of relapse in 123 of the 140 patients with a detection rate of 87.8 % (46 patients showed local relapse, 31 showed local and distant relapse, and 46 showed only distant relapse). In patients with relapse the mean serum PSA level was 9.08 ng/mL (median 5.1 ng/mL, range 2 - 60 ng/mL), the mean PSA doubling time was 5.6 months (median 3.5 months, range 0.4 - 48 months), and the mean PSA velocity was 15 ng/mL/year (median 8.8 ng/mL/year, range 0.4 - 87 ng/mL/year). Of the 123 patients with relapse, 77 (62.6 %) showed distant relapse with/without local relapse, and of these 77, 31 (40.2 %) showed oligometastatic disease (one or two distant lesions: lymph node lesions only in 16, bone lesions only in 14, and lymph node lesions and bone

  1. Beam related response of in vivo diode detectors for external radiotherapy

    Science.gov (United States)

    Baci, Syrja; Telhaj, Ervis; Malkaj, Partizan

    2016-03-01

    In Vivo Dosimetry (IVD) is a set of methods used in cancer treatment clinics to determine the real dose of radiation absorbed by target volume in a patient's body. IVD has been widely implemented in radiotherapy treatment centers and is now recommended part of Quality Assurance program by many International health and radiation organizations. Because of cost and lack of specialized personnel, IVD has not been practiced as yet, in Albanian radiotherapy clinics. At Hygeia Hospital Tirana, patients are irradiated with high energy photons generated by Elekta Synergy Accelerators. We have recently started experimenting with the purpose of establishing an IVD practice at this hospital. The first set of experiments was aimed at calibration of diodes that are going to be used for IVD. PMMA, phantoms by PTW were used to calibrate p - type Si, semiconductor diode dosimeters, made by PTW Freiburg for entrance dose. Response of the detectors is affected by energy of the beam, accumulated radiation dose, dose rate, temperature, angle against the beam axis, etc. Here we present the work done for calculating calibration factor and correction factors of source to surface distance, field size, and beam incidence for the entrance dose for both 6 MV photon beam and 18 MV photon beam. Dependence of dosimeter response was found to be more pronounced with source to surface distance as compared to other variables investigated.

  2. External beam radiotherapy for basal cell carcinoma. Local control and cosmetic outcome

    International Nuclear Information System (INIS)

    Background: The basal cell carcinoma which is often occurring in the elderly can be well treated by surgery. For large and recurrent lesions and in cosmetically difficult locations external beam radiotherapy provides an equally effective treatment alternative. Patients and Methods: From 1986 to 1999, 60 females and 39 males received primary radiotherapy for a total of 127 histologically verified basal cell carcinoma lesions. Tumors were mostly localized in the face at the temple, nose and forehead. Radiotherapy was applied with orthovoltage equipment and energies of up to 100 kV. Single doses ranged from 2 to 5 Gy related to the 80%-isodose depth. Weekly doses ranged from 8 to 25 Gy and total doses from 25 to 60 Gy. The mean follow-up period was 36±21 months. The acute sequelae were scored according to CTC criteria. Radiogenic late effects as single events were related to the radiation portal. Results: 3 months after treatment all besides one patient (99%) experienced complete tumor remission (CR). In all cases, acute radiation reaction occurred within the radiation portal: CTC Grade 1 in 100%, CTC Grade 2 in 54% and CTC Grade 3 in 30% of the cases. All side effects regressed under simple local measures without further complications. Late sequelae were observed in three cases. Overall cosmetic outcome was good to excellent in almost all patients (98%). In two cases (2%) a local recurrence was observed 6 and 20 months after radiotherapy. Conclusion: External beam (orthovoltage) radiotherapy is very effective and yields high tumor control rates and good cosmetic results in long-term follow-up. Former dermatological treatment concepts should be replaced by an ICRU-based radiophysical dose prescription and should respect the newer radiobiological fractionation principles. (orig.)

  3. Beam commissioning of a superconducting rotating-gantry for carbon-ion radiotherapy

    Science.gov (United States)

    Iwata, Y.; Fujimoto, T.; Matsuba, S.; Fujita, T.; Sato, S.; Furukawa, T.; Hara, Y.; Mizushima, K.; Saraya, Y.; Tansho, R.; Saotome, N.; Shirai, T.; Noda, K.

    2016-10-01

    A superconducting rotating-gantry for carbon-ion radiotherapy was developed. This isocentric gantry can transport carbon ions having kinetic energies of between E=430 and 48 MeV/u to an isocenter over an angle of ±180°, and is further capable of performing three-dimensional raster-scanning irradiation. Construction of the entire rotating-gantry system was completed by the end of September 2015. Prior to beam commissioning, phase-space distributions of extracted carbon beams from the synchrotron were deduced by using an empirical method. In this method, phase-space distributions at the extraction channel of the synchrotron were modeled with 8 parameters, and the best parameters were determined so as to minimize a difference between the calculated and measured beam profiles by using a simplex method. Based on the phase-space distributions, beam optics through the beam-transport lines as well as the rotating gantry were designed. Since horizontal and vertical beam emittances, as extracted slowly from the synchrotron, generally differ with each other, a horizontal-vertical beam coupling would occur when the gantry rotates. Thus, the size and shape of beam spots at the isocenter should vary depending on the gantry angle. To compensate for the difference in the emittances, we employed a method to utilize multiple Coulomb scattering of the beam particles by a thin scatterer. Having compensated for the emittances and designed beam optics through the rotating gantry, beam commissioning over various combinations of gantry angles and beam energies was performed. By finely tuning the superconducting quadrupoles of the rotating gantry, we could successfully obtain the designed beam quality, which satisfies the requirements of scanning irradiation.

  4. Constrained customization of non-coplanar beam orientations in radiotherapy of brain tumours

    Science.gov (United States)

    Rowbottom, Carl Graham; Oldham, Mark; Webb, Steve

    1999-02-01

    A methodology for the constrained customization of non-coplanar beam orientations in radiotherapy treatment planning has been developed and tested on a cohort of five patients with tumours of the brain. The methodology employed a combination of single and multibeam cost functions to produce customized beam orientations. The single-beam cost function was used to reduce the search space for the multibeam cost function, which was minimized using a fast simulated annealing algorithm. The scheme aims to produce well-spaced, customized beam orientations for each patient that produce low dose to organs at risk (OARs). The customized plans were compared with standard plans containing the number and orientation of beams chosen by a human planner. The beam orientation constraint-customized plans employed the same number of treatment beams as the standard plan but with beam orientations chosen by the constrained-customization scheme. Improvements from beam orientation constraint-customization were studied in isolation by customizing the beam weights of both plans using a dose-based downhill simplex algorithm. The results show that beam orientation constraint-customization reduced the maximum dose to the orbits by an average of 18.8 (, 1SD)% and to the optic nerves by 11.4 (, 1SD)% with no degradation of the planning target volume (PTV) dose distribution. The mean doses, averaged over the patient cohort, were reduced by 4.2 (, 1SD)% and 12.4 ( 1SD)% for the orbits and optic nerves respectively. In conclusion, the beam orientation constraint-customization can reduce the dose to OARs, for few-beam treatment plans, when compared with standard treatment plans developed by a human planner.

  5. Safety and Efficacy of Concurrent Cisplatin and Radiotherapy in Inoperable or Metastatic Squamous Cell Esophageal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Shaleen; Dimri, Kislay; Datta, Niloy R.; Rastogi, Neeraj; Lal, Punita; Das, Koilpillai J. Maria; Ayyagari, Sundar [Sanjay Gandhi Postgraduate Inst. of Medical Sciences, Lucknow (India). Dept of Radiotherapy

    2002-09-01

    Between August 1996 and May 1999, 50 consecutive, previously untreated patients with carcinoma of the esophagus and who were inoperable for various reasons were treated with weekly doses of cisplatin (35 mg/m{sup 2}, maximum 7 cycles) concurrent with either 66 Gy/33 fractions external beam radiotherapy (EBRT) (n=42) or 50 Gy/25 fractions EBRT and two insertions of high-dose-rate intraluminal radiotherapy of 6 Gy each, spaced a week apart (n=8). Eighty-two percent (41/50) of the patients received the stipulated radiotherapy (RT) dose. Seventy-six percent (38/50) received at least 6 cycles of chemotherapy. Neutropenia in the form of WHO grade II-12% (6/50) and grade III-2% (1/50) was observed. Grade III emesis was seen in 8% (4/50). Improvement in the swallowing status was seen in 84% (42/50). Median duration of dysphagia relief was 6 months. The median overall survival was 9 months with 17% estimated to be alive after 4 years. Combined treatment with single agent cisplatin and definitive radiotherapy for inoperable cancer of the esophagus is safe, well tolerated and reasonably efficacious.

  6. A quality audit program for external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, W.F.; Stovall, M. [Univ. of Texas, Houston, TX (United States)

    1993-12-31

    For more than 25 years, the University of Texas M. D. Anderson Cancer Center has had a quality audit program using mailed dosimeters to verify radiation therapy machine output. Two programs, one compulsory and one voluntary, presently monitor therapy beams at more than 1000 megavoltage-therapy facilities. A successful program requires two major components: a high-precision thermoluminescent dosimeter (TLD) system and dedicated staff that interact closely with the users to resolve discrepancies. The TLD system, the logistics used, and the human interaction of these programs are described. Examples show that the programs can identify major discrepancies, exceeding 5 %, as well as discrepancies as small as 3%.

  7. Particle-beam accelerators for radiotherapy and radioisotopes

    International Nuclear Information System (INIS)

    The philosophy used in developing the new PIGMI technology was that the parameters chosen for physics research machines are not necessarily the right ones for a dedicated therapy or radioisotope machine. In particular, the beam current and energy can be optimized, and the design should emphasize minimum size, simplicity and reliability of operation, and economy in capital and operating costs. A major part of achieving these goals lay in raising the operating frequency and voltage gradient of the accelerator, which shrinks the diameter and length of the components. Several other technical innovations resulted in major system improvements. One of these is a radically new type of accelerator structure named the radio-frequency quadrupole (RFQ) accelerator. This allowed us to eliminate the large, complicated ion source used in previous ion accelerators, and to achieve a very high quality accelerated beam. Also, by using advanced permanent magnet materials to make the focusing elements, the system becomes much simpler. Other improvements have been made in all of the accelerator components and in the methods for operating them. These will be described, and design and costing information examples given for several possible therapy and radioisotope production machines

  8. Dosimetry quality audit of high energy photon beams in greek radiotherapy centers

    International Nuclear Information System (INIS)

    Background and purpose: Dosimetry quality audits and intercomparisons in radiotherapy centers is a useful tool in order to enhance the confidence for an accurate therapy and to explore and dissolve discrepancies in dose delivery. This is the first national comprehensive study that has been carried out in Greece. During 2002 - 2006 the Greek Atomic Energy Commission performed a dosimetry quality audit of high energy external photon beams in all (23) Greek radiotherapy centers, where 31 linacs and 13 Co-60 teletherapy units were assessed in terms of their mechanical performance characteristics and relative and absolute dosimetry. Materials and Methods: The quality audit in dosimetry of external photon beams took place by means of on-site visits, where certain parameters of the photon beams were measured, calculated and assessed according to a specific protocol and the IAEA TRS 398 dosimetry code of practice. In each radiotherapy unit (Linac or Co-60), certain functional parameters were measured and the results were compared to tolerance values and limits. Doses in water under reference and non reference conditions were measured and compared to the stated values. Also, the treatment planning systems (TPS) were evaluated with respect to irradiation time calculations. Results: The results of the mechanical tests, dosimetry measurements and TPS evaluation have been presented in this work and discussed in detail. This study showed that Co-60 units had worse performance mechanical characteristics than linacs. 28% of all irradiation units (23% of linacs and 42% of Co-60 units) exceeded the acceptance limit at least in one mechanical parameter. Dosimetry accuracy was much worse in Co60 units than in linacs. 61% of the Co60 units exhibited deviations outside ±3% and 31% outside ±5%. The relevant percentages for the linacs were 24% and 7% respectively. The results were grouped for each hospital and the sources of errors (functional and human) have been investigated and

  9. Relative biological effectiveness (RBE) of proton beams in radiotherapy

    International Nuclear Information System (INIS)

    Treatment planning in proton therapy uses a generic value for the Relative Biological Efficiency (RBE) of 1.1 relative to 60Co gamma-rays throughout the Spread Out Bragg Peak (SOBP). We have studied the variation of the RBE at three positions in the SOBP of the 76 and 201 MeV proton beams used for cancer treatment at the Institut Curie Proton Therapy in Orsay (ICPO) in two human tumor cell lines using clonogenic cell death and the incidence of DNA double-strand breaks (DSB) as measured by pulse-field gel electrophoresis without and with endonuclease treatment to reveal clustered lesions as endpoints.The RBE for induced cell killing by the 76 MeV beam increased with depth in the SOBP. However for the 201 MeV protons it was close to that for 137Cs gamma-rays and did not vary significantly. The incidence of DSBs and clustered lesions was higher for protons than for 137Cs g-rays, but did not depend on the proton energy or the position in the SOBP. In the second part of our work, we have shown using cell clones made deficient for known repair genes by stable or transient shRNA transfection, that the D-NHEJ pathway determine the response to protons. The response of DNA damages created in the distal part of the 76 MeV SOBP suggests that those damages belong to the class of DNA 'complex lesions' (LMDS). It also appears that the particle fluence is a major determinant of the outcome of treatment in the distal part of the SOBP. (author)

  10. Feasibility of proton transmission-beam stereotactic ablative radiotherapy versus photon stereotactic ablative radiotherapy for lung tumors: a dosimetric and feasibility study.

    Directory of Open Access Journals (Sweden)

    Benjamin Mou

    Full Text Available Stereotactic ablative radiotherapy is being increasingly adopted in the treatment of lung tumors. The use of proton beam therapy can further reduce dose to normal structures. However, uncertainty exists in proton-based treatment plans, including range uncertainties, large sensitivity to position uncertainty, and calculation of dose deposition in heterogeneous areas. This study investigated the feasibility of proton transmission beams, i.e. without the Bragg peak, to treat lung tumors with stereotactic ablative radiotherapy. We compared three representative treatment plans using proton transmission beams versus conformal static-gantry photon beams. It was found that proton treatment plans using transmission beams passing through the patient were feasible and demonstrated lower dose to normal structures and markedly reduced treatment times than photon plans. This is the first study to demonstrate the feasibility of proton-based stereotactic ablative radiotherapy planning for lung tumors using proton transmission beams alone. Further research using this novel approach for proton-based planning is warranted.

  11. Clinical application of intensity and energy modulated radiotherapy with photon and electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Xiangkui Mu

    2005-01-01

    In modern, advanced radiotherapy (e.g. intensity modulated photon radiotherapy, IMXT) the delivery time for each fraction becomes prolonged to 10-20 minutes compared with the conventional, commonly 2-5 minutes. The biological effect of this prolongation is not fully known. The large number of beam directions in IMXT commonly leads to a large integral dose in the patient. Electrons would reduce the integral dose but are not suitable for treating deep-seated tumour, due to their limited penetration in tissues. By combining electron and photon beams, the dose distributions may be improved compared with either used alone. One obstacle for using electron beams in clinical routine is that there is no available treatment planning systems that optimise electron beam treatments in a similar way as for IMXT. Protons have an even more pronounced dose fall-off, larger penetration depth and less penumbra widening than electrons and are therefore more suitable for advanced radiotherapy. However, proton facilities optimised for advanced radiotherapy are not commonly available. In some instances electron beams may be an acceptable surrogate. The first part of this study is an experimental in vitro study where the situation in a tumour during fractionated radiotherapy is simulated. The effect of the prolonged fraction time is compared with the predictions by radiobiological models. The second part is a treatment planning study to analyse the mixing of electron and photon beams for at complex target volume in comparison with IMXT. In the next step a research version of an electron beam optimiser was used for the improvement of treatment plans. The aim was to develop a method for translating crude energy and intensity matrices for optimised electrons into a deliverable treatment plan without destroying the dose distribution. In the final part, different methods of treating the spinal canal in medulloblastoma were explored in a treatment planning study that was evaluated with

  12. Nanoscale radiation transport and clinical beam modeling for gold nanoparticle dose enhanced radiotherapy (GNPT) using X-rays.

    Science.gov (United States)

    Zygmanski, Piotr; Sajo, Erno

    2016-01-01

    We review radiation transport and clinical beam modelling for gold nanoparticle dose-enhanced radiotherapy using X-rays. We focus on the nanoscale radiation transport and its relation to macroscopic dosimetry for monoenergetic and clinical beams. Among other aspects, we discuss Monte Carlo and deterministic methods and their applications to predicting dose enhancement using various metrics.

  13. Radiotherapy

    International Nuclear Information System (INIS)

    The need for radiotherapy research is exemplified by the 100,000 cancer patients who will fail treatment locally and/or regionally annually for the next several years but who would benefit from better local treatment modalities. Theoretically, all of the areas of investigation discussed in this projection paper have the potential to significantly improve local-regional treatment of cancer by radiotherapy alone or in combination with other modalities. In many of the areas of investigation discussed in this paper encouraging results have been obtained in cellular and animal tumor studies and in limited studies in humans as well. In the not too distant future the number of patients who would benefit from better local control may increase by tens of thousands if developments in chemotherapy and/or immunotherapy provide a means to eradicate disseminated microscopic foci of cancer. Thus the efforts to improve local-regional control take on even greater significance

  14. Differentiated Thyroid Cancer with Extrathyroidal Extension: Prognosis and the Role of External Beam Radiotherapy

    Directory of Open Access Journals (Sweden)

    Michael A. Sia

    2010-01-01

    Full Text Available A study was performed to identify variables that affected cause-specific survival (CSS and local relapse-free rate (LRFR in patients with differentiated thyroid cancer (DTC and extrathyroid extension (ETE and to examine the role of external beam radiotherapy (XRT. Prognostic factors were similar to those found in studies of all patients with DTC. In patients with postoperative gross residual disease treated with radiotherapy, 10-year CSS and LRFR were 48% and 90%. For patients with no residual or microscopic disease, 10-year CSS and LRFR were 92% and 93%. In patients older than 60 years with T3 ETE but no gross residual disease postoperatively there was an improved LRFR at 5 years of 96%, compared to 87.5% without XRT (P=.02. Patients with gross ETE benefit from XRT and there may be a potential benefit in reducing locoregional failure in patients over 60 years with minimal extrathyroidal extension (T3.

  15. Calculation of uncertainties in the protocol of dosimetry for Co 60 beams in Radiotherapy

    International Nuclear Information System (INIS)

    The objective in this work is to show how the uncertainty is possible to know in the determination of the absorbed dose in Co 60 photon beams and to establish in a rational form, tolerance levels for this. It is took as base the spanish protocol of dosimetry in Radiotherapy. We have been centered in a Co 60 beam. We utilized the statistical theory of little samples. We allowed to suggest a new approach about the treatment of the tolerance levels and the uncertainty of the measurement. After two years of experience in the practical hospitable application we have gotten to put around 1 % uncertainty in the absolute dosimetry of the Co 60 beam. The presented protocol allows to execute the accuracy requirements in the determination of absorbed doses. (Author)

  16. Supine proton beam craniospinal radiotherapy using a novel tabletop adapter

    Energy Technology Data Exchange (ETDEWEB)

    Buchsbaum, Jeffrey C., E-mail: jbuchsba@iupui.edu [IU Health Proton Therapy Center, Bloomington, IN (United States); Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States); Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN (United States); Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, IN (United States); Besemer, Abby; Simmons, Joseph; Hoene, Ted; Simoneaux, Victor; Sandefur, Amy [IU Health Proton Therapy Center, Bloomington, IN (United States); Wolanski, Mark; Li, Zhao; Cheng, Chee-Wei [IU Health Proton Therapy Center, Bloomington, IN (United States); Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States)

    2013-04-01

    To develop a device that allows supine craniospinal proton and photon therapy to the vast majority of proton and photon facilities currently experiencing limitations as a result of couch design issues. Plywood and carbon fiber were used for the development of a prototype unit. Once this was found to be satisfactory after all design issues were addressed, computer-assisted design (CAD) was used and carbon fiber tables were built to our specifications at a local manufacturer of military and racing car carbon fiber parts. Clinic-driven design was done using real-time team discussion for a prototype design. A local machinist was able to construct a prototype unit for us in <2 weeks after the start of our project. Once the prototype had been used successfully for several months and all development issues were addressed, a custom carbon fiber design was developed in coordination with a carbon fiber manufacturer in partnership. CAD methods were used to design the units to allow oblique fields from head to thigh on patients up to 200 cm in height. Two custom-designed carbon fiber craniospinal tabletop designs now exist: one long and one short. Four are in successful use in our facility. Their weight tolerance is greater than that of our robot table joint (164 kg). The long unit allows for working with taller patients and can be converted into a short unit as needed. An affordable, practical means of doing supine craniospinal therapy with protons or photons can be used in most locations via the use of these devices. This is important because proton therapy provides a much lower integral dose than all other therapy methods for these patients and the supine position is easier for patients to tolerate and for anesthesia delivery. These units have been successfully used for adult and pediatric supine craniospinal therapy, proton therapy using oblique beams to the low pelvis, treatment of various spine tumors, and breast-sparing Hodgkin's therapy.

  17. SU-E-T-221: Investigation of Lower Energy (< 6 MV) Photon Beams for Cancer Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y; Ming, X [Tianjin University, Tianjin (China); New Haven Hospital, New Haven, CT (United States); Feng, Y [Tianjin University, Tianjin (China); East Carolina University, Rockville, MD (United States); Zhou, L [New Haven Hospital, New Haven, CT (United States); West China Hospital, Sichuan University, Chengdu, Sichuan (China); Ahmad, M; Deng, J [New Haven Hospital, New Haven, CT (United States); Nguyen, K; Griffin, M [William Backus Hospital, Norwich, CT (United States)

    2014-06-01

    Purpose: To study the potential applications of the lower energy (< 6MV) photon beams in the radiotherapeutic management of pediatric cancer and lung cancer patients. Methods: Photon beams of 2, 3, 4, 5 and 6MV were first simulated with EGS4/BEAM and then used for Monte-Carlo dose calculations. For four pediatric patients with abdominal and brain lesions, six 3D-conformal radiotherapy (3DCRT) plans were generated using single photon energy (2 to 6MV) or mixed energies (3 and 6MV). Furthermore, a virtual machine of 3 and 6MV was commissioned in a treatment planning system (TPS) based on Monte-Carlo simulated data. Three IMRT plans of a lung cancer patient were generated on this virtual machine. All plans were normalized to D95% of target dose for 6MV plan and then compared in terms of integral dose and OAR sparing. Results: For the four pediatric patients, the integral dose for the 2, 3, 4 and 5MV plans increased by 9%, 5%, 3.5%, 1.7%, respectively as compared to 6MV. Almost all OARs in the 2MV plan received more than 10% more doses than 6MV. Mixed energy 3DCRT plans were of the same quality as 6MV plans. For the lung IMRT plans, both the 3MV plan and the mixed beam plan showed better OAR sparing in comparison to 6MV plan. Specifically, the maximum and mean doses to the spinal cord in the mixed energy plan were lower by 21% and 16%, respectively. Conclusion: Single lower energy photon beam was found to be inferior to 6MV in the radiotherapy of pediatric patients and lung cancer patients when the integral doses and the doses to the OARs were considered. However, mixed energy plans combining low with high energy beams showed significant OAR sparing while maintaining the same PTV coverage. Investigation with more patient data is ongoing for further confirmation.

  18. Development of a postal dosimetric system for quality assurance programs in radiotherapy using fotons beams in non references conditions

    CERN Document Server

    Marin, A

    2003-01-01

    In radiotherapy, to cure the primary tumor, the absorbed dose delivered at the target volume should have an accuracy better than +- 5%. As the basic aim in radiotherapy is the eradication of the primary tumor with the smallest possible damage to the health tissues, it is necessary to guarantee that the dose delivered to the patient in different depths and treatment configurations has the right accuracy. For this reason, a quality control program should be carried out by regulatory and national standardization programs including postal evaluation of the beam dosimetry are also necessary. Since many years Brazil is running a postal quality control program in radiotherapy in reference conditions, Nevertheless it should be increased to include also measurements in non reference conditions. In this paper we present a new dosimetric postal system using thermoluminescent dosimeters (TLD-100 in powder) for photon beams quality control in radiotherapy, in non reference conditions. This system has been checked and appl...

  19. Investigations of high mobility single crystal chemical vapor deposition diamond for radiotherapy photon beam monitoring

    Science.gov (United States)

    Tromson, D.; Descamps, C.; Tranchant, N.; Bergonzo, P.; Nesladek, M.; Isambert, A.

    2008-03-01

    The intrinsic properties of diamond make this material theoretically very suitable for applications in medical physics. Until now ionization chambers have been fabricated from natural stones and are commercialized by PTW, but their fairly high costs and long delivery times have often limited their use in hospital. The properties of commercialized intrinsic polycrystalline diamond were investigated in the past by many groups. The results were not completely satisfactory due to the nature of the polycrystalline material itself. In contrast, the recent progresses in the growth of high mobility single crystal synthetic diamonds prepared by chemical vapor deposition (CVD) technique offer new alternatives. In the framework of the MAESTRO project (Methods and Advanced Treatments and Simulations for Radio Oncology), the CEA-LIST is studying the potentialities of synthetic diamond for new techniques of irradiation such as intensity modulated radiation therapy. In this paper, we present the growth and characteristics of single crystal diamond prepared at CEA-LIST in the framework of the NoRHDia project (Novel Radiation Hard CVD Diamond Detector for Hadrons Physics), as well as the investigations of high mobility single crystal CVD diamond for radiotherapy photon beam monitoring: dosimetric analysis performed with the single crystal diamond detector in terms of stability and repeatability of the response signal, signal to noise ratio, response speed, linearity of the signal versus the absorbed dose, and dose rate. The measurements performed with photon beams using radiotherapy facilities demonstrate that single crystal CVD diamond is a good alternative for air ionization chambers for beam quality control.

  20. MRI assessment of cervical cancer for adaptive radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Johannes C.A.; Schirl, Gertrude; Baldinger, Anja; Poetter, Richard [Medical Univ. of Vienna (Austria). Dept. of Radiotherapy; Helbich, Thomas H. [Medical Univ. of Vienna (Austria). Dept of Radiology

    2009-05-15

    Purpose: To assess the importance of the information obtained from MRI for adaptive cervix cancer radiotherapy. Patients and methods: 49 patients with cervix cancer, treated by external-beam radiotherapy (EBRT) and MRI-assisted high-dose-rate brachytherapy {+-} concomitant cisplatin, underwent MRI at diagnosis and at the time of brachytherapy fractions. 190 MRI examinations were performed. Pretreatment scans were correlated with clinical examination (CE) findings. Measurements in 3-D of the tumor extension and also of the distance from the tumor to the pelvic side wall were performed using both MRI and CE. The tumor volume regression induced initially by EBRT and the subsequent regression after each brachytherapy fraction were assessed. Results: MRI and CE showed 92% agreement in overall parametrial staging and 73% agreement in terms of vaginal involvement. There was, however, disagreement in parametrial side (right/left) classification in 25% of the parametria examined. These were patients with unilateral displacement of the cervix and contralateral invasion of the parametrium. The mean tumor volume on the pretreatment MRI scan (GTVD) was 61 cm{sup 3}. At the time of the four brachytherapy fractions the mean was 16 cm{sup 3}, 10 cm{sup 3}, 9 cm{sup 3}, and 8 cm{sup 3}, defined as the GTVBT plus the gray zones in the parametria. Conclusion: CE and MRI findings agree well in terms of overall staging. The clinical assessment of side-specific parametrial invasion improved when having access to the additional knowledge obtained from MRI. The greatest decrease in tumor volume occurs during EBRT, whereas tumor regression between the first and subsequent brachytherapy fractions is minor. (orig.)

  1. Incidence of Secondary Cancer Development After High-Dose Intensity-Modulated Radiotherapy and Image-Guided Brachytherapy for the Treatment of Localized Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zelefsky, Michael J., E-mail: Zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Housman, Douglas M.; Pei Xin; Alicikus, Zumre; Magsanoc, Juan Martin [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Dauer, Lawrence T.; St Germain, Jean [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Yamada, Yoshiya; Kollmeier, Marisa; Cox, Brett [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zhang Zhigang [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2012-07-01

    Purpose: To report the incidence and excess risk of second malignancy (SM) development compared with the general population after external beam radiotherapy (EBRT) and brachytherapy to treat prostate cancer. Methods and Materials: Between 1998 and 2001, 1,310 patients with localized prostate cancer were treated with EBRT (n = 897) or brachytherapy (n = 413). We compared the incidence of SMs in our patients with that of the general population extracted from the National Cancer Institute's Surveillance, Epidemiology, and End Results data set combined with the 2000 census data. Results: The 10-year likelihood of SM development was 25% after EBRT and 15% after brachytherapy (p = .02). The corresponding 10-year likelihood for in-field SM development in these groups was 4.9% and 1.6% (p = .24). Multivariate analysis showed that EBRT vs. brachytherapy and older age were the only significant predictors for the development of all SMs (p = .037 and p = .030), with a trend for older patients to develop a SM. The increased incidence of SM for EBRT patients was explained by the greater incidence of skin cancer outside the radiation field compared with that after brachytherapy (10.6% and 3.3%, respectively, p = .004). For the EBRT group, the 5- and 10-year mortality rate was 1.96% and 5.1% from out-of field cancer, respectively; for in-field SM, the corresponding mortality rates were 0.1% and 0.7%. Among the brachytherapy group, the 5- and 10-year mortality rate related to out-of field SM was 0.8% and 2.7%, respectively. Our observed SM rates after prostate RT were not significantly different from the cancer incidence rates in the general population. Conclusions: Using modern sophisticated treatment techniques, we report low rates of in-field bladder and rectal SM risks after prostate cancer RT. Furthermore, the likelihood of mortality secondary to a SM was unusual. The greater rate of SM observed with EBRT vs. brachytherapy was related to a small, but significantly

  2. Incidence of Secondary Cancer Development After High-Dose Intensity-Modulated Radiotherapy and Image-Guided Brachytherapy for the Treatment of Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Purpose: To report the incidence and excess risk of second malignancy (SM) development compared with the general population after external beam radiotherapy (EBRT) and brachytherapy to treat prostate cancer. Methods and Materials: Between 1998 and 2001, 1,310 patients with localized prostate cancer were treated with EBRT (n = 897) or brachytherapy (n = 413). We compared the incidence of SMs in our patients with that of the general population extracted from the National Cancer Institute’s Surveillance, Epidemiology, and End Results data set combined with the 2000 census data. Results: The 10-year likelihood of SM development was 25% after EBRT and 15% after brachytherapy (p = .02). The corresponding 10-year likelihood for in-field SM development in these groups was 4.9% and 1.6% (p = .24). Multivariate analysis showed that EBRT vs. brachytherapy and older age were the only significant predictors for the development of all SMs (p = .037 and p = .030), with a trend for older patients to develop a SM. The increased incidence of SM for EBRT patients was explained by the greater incidence of skin cancer outside the radiation field compared with that after brachytherapy (10.6% and 3.3%, respectively, p = .004). For the EBRT group, the 5- and 10-year mortality rate was 1.96% and 5.1% from out-of field cancer, respectively; for in-field SM, the corresponding mortality rates were 0.1% and 0.7%. Among the brachytherapy group, the 5- and 10-year mortality rate related to out-of field SM was 0.8% and 2.7%, respectively. Our observed SM rates after prostate RT were not significantly different from the cancer incidence rates in the general population. Conclusions: Using modern sophisticated treatment techniques, we report low rates of in-field bladder and rectal SM risks after prostate cancer RT. Furthermore, the likelihood of mortality secondary to a SM was unusual. The greater rate of SM observed with EBRT vs. brachytherapy was related to a small, but significantly increased

  3. Optimal beam arrangement for pulmonary ventilation image-guided intensity-modulated radiotherapy for lung cancer

    OpenAIRE

    Wang, Ruihao; Zhang, Shuxu; YU, HUI; Lin, Shengqu; Zhang, Guoqian; Tang, Rijie; Qi, Bin

    2014-01-01

    Background The principal aim of this study was to evaluate the feasibility of incorporating four-dimensional (4D)-computed tomography (CT)-based functional information into treatment planning and to evaluate the potential benefits of individualized beam setups to better protect lung functionality in patients with non-small cell lung cancer (NSCLC). Methods Peak-exhale and peak-inhale CT scans were carried out in 16 patients with NSCLC treated with intensity-modulated radiotherapy (IMRT). 4D-C...

  4. Endoscopic findings of rectal mucosal damage after pelvic radiotherapy for cervical carcinoma: correlation of rectal mucosal damage with radiation dose and clinical symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Gyu; Huh, Seung Jae; Park, Won [Dept. of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2013-06-15

    To describe chronic rectal mucosal damage after pelvic radiotherapy (RT) for cervical cancer and correlate these findings with clinical symptoms and radiation dose. Thirty-two patients who underwent pelvic RT were diagnosed with radiation-induced proctitis based on endoscopy findings. The median follow-up period was 35 months after external beam radiotherapy (EBRT) and intracavitary radiotherapy (ICR). The Vienna Rectoscopy Score (VRS) was used to describe the endoscopic findings and compared to the European Organization for Research and Treatment of Cancer (EORTC)/Radiation Therapy Oncology Group (RTOG) morbidity score and the dosimetric parameters of RT (the ratio of rectal dose calculated at the rectal point [RP] to the prescribed dose, biologically effective dose [BED] at the RP in the ICR and EBRT plans, {alpha}/{beta} = 3). Rectal symptoms were noted in 28 patients (rectal bleeding in 21 patients, bowel habit changes in 6, mucosal stools in 1), and 4 patients had no symptoms. Endoscopic findings included telangiectasia in 18 patients, congested mucosa in 20, ulceration in 5, and stricture in 1. The RP ratio, BEDICR, BEDICR+EBRT was significantly associated with the VRS (RP ratio, median 76.5%; BEDICR, median 37.1 Gy3; BEDICR+EBRT, median 102.5 Gy3; p < 0.001). The VRS was significantly associated with the EORTC/RTOG score (p = 0.038). The most prevalent endoscopic findings of RT-induced proctitis were telangiectasia and congested mucosa. The VRS was significantly associated with the EORTC/RTOG score and RP radiation dose.

  5. Monte Carlo based beam model using a photon MLC for modulated electron radiotherapy

    International Nuclear Information System (INIS)

    Purpose: Modulated electron radiotherapy (MERT) promises sparing of organs at risk for certain tumor sites. Any implementation of MERT treatment planning requires an accurate beam model. The aim of this work is the development of a beam model which reconstructs electron fields shaped using the Millennium photon multileaf collimator (MLC) (Varian Medical Systems, Inc., Palo Alto, CA) for a Varian linear accelerator (linac). Methods: This beam model is divided into an analytical part (two photon and two electron sources) and a Monte Carlo (MC) transport through the MLC. For dose calculation purposes the beam model has been coupled with a macro MC dose calculation algorithm. The commissioning process requires a set of measurements and precalculated MC input. The beam model has been commissioned at a source to surface distance of 70 cm for a Clinac 23EX (Varian Medical Systems, Inc., Palo Alto, CA) and a TrueBeam linac (Varian Medical Systems, Inc., Palo Alto, CA). For validation purposes, measured and calculated depth dose curves and dose profiles are compared for four different MLC shaped electron fields and all available energies. Furthermore, a measured two-dimensional dose distribution for patched segments consisting of three 18 MeV segments, three 12 MeV segments, and a 9 MeV segment is compared with corresponding dose calculations. Finally, measured and calculated two-dimensional dose distributions are compared for a circular segment encompassed with a C-shaped segment. Results: For 15 × 34, 5 × 5, and 2 × 2 cm2 fields differences between water phantom measurements and calculations using the beam model coupled with the macro MC dose calculation algorithm are generally within 2% of the maximal dose value or 2 mm distance to agreement (DTA) for all electron beam energies. For a more complex MLC pattern, differences between measurements and calculations are generally within 3% of the maximal dose value or 3 mm DTA for all electron beam energies. For the two

  6. Comparison between the lateral penumbra of a collimated double-scattered beam and uncollimated scanning beam in proton radiotherapy

    International Nuclear Information System (INIS)

    Intensity modulated proton radiotherapy (IMPT) can reduce the dose to critical structures by optimizing the distribution and intensity of individual pencil beams. The IMPT can be delivered by dynamically scanning a pencil beam with variable intensity and energy across the tumor target volume. The lateral penumbra of an uncollimated pencil beam is compromised, however, by the scattering in air between the vacuum window and the patient, and by the initial beam size. In this study, we compare the transversal penumbra of a pencil beam to the one of a collimated Gaussian broad divergent beam, such as the one produced by the double scattering system, for different range compensator thicknesses, collimator-to-surface distances (CSD), proton range and pencil beam sizes (σ0). The effect of vacuum and helium in the nozzle on the pencil beam lateral profile further downstream is also investigated. The lateral spatial intensity distribution for the collimated Gaussian broad divergent proton beam is modeled using the generalized Fermi-Eyges theory. The model is validated with measurements of the lateral profile in water at different depths for two different ranges (7.7 cm and 22.1 cm, respectively). Nearly 2500 treatment fields are analyzed to establish typical clinical beam configurations, such as the range compensator thicknesses, CSD and range, which we use to predict the 80%-20% lateral penumbra. The penumbra of the collimated broad divergent beam is calculated for fixed source-to-surface distance (SSD) of 220 cm and source size of 2.5 cm (σ). The results show that the model predicts the penumbra at different water depths with accuracy better than 0.2 mm. At depths larger than 7.6 cm (minimum range of the clinical fields analyzed), the accuracy is better than 3%. The treatment fields feature the following average configuration: the range compensator thickness of 6.5 ± 2.8 cm (max 19.4 cm), CSD 11.9 ± 3.8 cm (max 29.4 cm) and range of 16.0 ± 6.1 cm. The penumbra of a

  7. Changes in Pulmonary Function After Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, or Proton Beam Therapy for Non-Small-Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Guerra, Jose L. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Hospitales Universitarios Virgen del Rocio, Seville (Spain); Department of Medicine, Universitat Autonoma de Barcelona, Barcelona (Spain); Gomez, Daniel R., E-mail: dgomez@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhuang Yan; Levy, Lawrence B. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Eapen, George [Department of Pulmonary Medicine, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liu, Hongmei; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Liao Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-07-15

    Purpose: To investigate the extent of change in pulmonary function over time after definitive radiotherapy for non-small-cell lung cancer (NSCLC) with modern techniques and to identify predictors of changes in pulmonary function according to patient, tumor, and treatment characteristics. Patients and Methods: We analyzed 250 patients who had received {>=}60 Gy radio(chemo)therapy for primary NSCLC in 1998-2010 and had undergone pulmonary function tests before and within 1 year after treatment. Ninety-three patients were treated with three-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy, and 60 with proton beam therapy. Postradiation pulmonary function test values were evaluated among individual patients compared with the same patient's preradiation value at the following time intervals: 0-4 (T1), 5-8 (T2), and 9-12 (T3) months. Results: Lung diffusing capacity for carbon monoxide (DLCO) was reduced in the majority of patients along the three time periods after radiation, whereas the forced expiratory volume in 1 s per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, radiotherapy dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume, lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC. Conclusions: Lung diffusing capacity for carbon monoxide is reduced in the majority of patients after radiotherapy with modern techniques. Multiple factors, including gross tumor volume, preradiation lung function, and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology, such as proton beam therapy or

  8. Changes in Pulmonary Function After Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, or Proton Beam Therapy for Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Purpose: To investigate the extent of change in pulmonary function over time after definitive radiotherapy for non-small-cell lung cancer (NSCLC) with modern techniques and to identify predictors of changes in pulmonary function according to patient, tumor, and treatment characteristics. Patients and Methods: We analyzed 250 patients who had received ≥60 Gy radio(chemo)therapy for primary NSCLC in 1998–2010 and had undergone pulmonary function tests before and within 1 year after treatment. Ninety-three patients were treated with three-dimensional conformal radiotherapy, 97 with intensity-modulated radiotherapy, and 60 with proton beam therapy. Postradiation pulmonary function test values were evaluated among individual patients compared with the same patient’s preradiation value at the following time intervals: 0–4 (T1), 5–8 (T2), and 9–12 (T3) months. Results: Lung diffusing capacity for carbon monoxide (DLCO) was reduced in the majority of patients along the three time periods after radiation, whereas the forced expiratory volume in 1 s per unit of vital capacity (FEV1/VC) showed an increase and decrease after radiation in a similar percentage of patients. There were baseline differences (stage, radiotherapy dose, concurrent chemotherapy) among the radiation technology groups. On multivariate analysis, the following features were associated with larger posttreatment declines in DLCO: pretreatment DLCO, gross tumor volume, lung and heart dosimetric data, and total radiation dose. Only pretreatment DLCO was associated with larger posttreatment declines in FEV1/VC. Conclusions: Lung diffusing capacity for carbon monoxide is reduced in the majority of patients after radiotherapy with modern techniques. Multiple factors, including gross tumor volume, preradiation lung function, and dosimetric parameters, are associated with the DLCO decline. Prospective studies are needed to better understand whether new radiation technology, such as proton beam therapy

  9. Telerobotic system concept for real-time soft-tissue imaging during radiotherapy beam delivery

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, Jeffrey; Salisbury, Kenneth; Hristov, Dimitre [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Department of Computer Science and Department of Surgery, Stanford University, Stanford, California 94305 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States)

    2010-12-15

    , as would be enabled by real-time imaging, gross tumor volume coverage was identical while notable reductions of bladder and rectal volumes exposed to large doses were possible. The quality of U.S. images obtained during beam operation was not appreciably degraded by radiofrequency interference and 2D tracking of a phantom object in U.S. images obtained with the beam on/off yielded no significant differences. Conclusions: Remotely controlled robotic U.S. imaging is feasible in the radiotherapy environment and for the first time may offer real-time volumetric soft-tissue guidance concurrent with radiotherapy delivery.

  10. Outcome and Predictive Factors in Uterine Carcinosarcoma Using Postoperative Radiotherapy: A Rare Cancer Network Study.

    Science.gov (United States)

    Zwahlen, Daniel R; Schick, Ulrike; Bolukbasi, Yasemin; Thariat, Juliette; Abdah-Bortnyak, Roxolyana; Kuten, Abraham; Igdem, Sefik; Caglar, Hale; Ozsaran, Zeynep; Loessl, Kristina; Belkaaloul, Kaouthar Khanfir; Villette, Sylviane; Vees, Hansjörg

    2016-06-28

    Uterine carcinosarcomas (UCS) are rare tumors. Consensus regarding therapeutic management in non-metastatic disease is lacking. This study reports on outcome and predictive factors when using postoperative radiotherapy. We analyzed a retrospective analysis in 124 women treated between 1987-2007 in the framework of the Rare-Cancer-Network. Median follow-up was 27 months. Postoperative pelvic EBRT was administered in 105 women (85%) and 92 patients (74%) received exclusive or additional vaginal brachytherapy. Five-year overall survival (OS), disease-free survival (DFS), cancer specific survival (CSS) and locoregional control (LRC) were 51.6% (95% CI 35-73%), 53.7% (39-71%), 58.6% (38-74%) and 48% (38-67%). Multivariate analysis showed that external beam radiation therapy (EBRT) >50Gy was an independent prognostic factor for better OS (P=0.03), CSS (P=0.02) and LRC (P=0.01). Relative risks (RR) for better OS (P=0.02), DFS (P=0.04) and LRC (P=0.01) were significantly associated with younger age (≤60 years). Higher brachytherapy (BT)-dose (>9Gy) improved DFS (P=0.04) and LRC (P=0.008). We concluded that UCS has high systemic failure rate. Local relapse was reduced by a relative risk factor of over three in all stages of diseases when using higher doses for EBRT and brachytherapy. Postoperative RT was most effective in UCS stage I/II-diseases. PMID:27441069

  11. Inhomogeneities in high energy photon beams used in radiotherapy. Experimental and theoretical studies

    International Nuclear Information System (INIS)

    This work is dedicated to the influence of the human body inhomogeneities on the dose distribution for high energy photons beams used in Radiotherapy. It consists in an experimental part and a theoretical analysis leading to original models of calculation. We study essentially, - the beam quality of the machines used and its influence on some basic dosimetric quantities and on the response of an ionization chamber. - The dose perturbation due to off-axis heterogeneous volumes at off-axis points of measurement; a model is suggested to take into account the perturbation of the multiple scatter. The perturbation of the dose in the transition region, between water equivalent medium and heterogeneous medium (air) is also investigated. The last part is devoted to computer applications of the proposed correction methods and to a comparison between the different computerized treatment planning systems which take into account of inhomogeneities

  12. Intraoperative Radiotherapy for Breast Cancer: The Lasting Effects of a Fleeting Treatment

    Directory of Open Access Journals (Sweden)

    Harriet B. Eldredge-Hindy

    2014-01-01

    Full Text Available In well-selected patients who choose to pursue breast conservation therapy (BCT for early-stage breast cancer, partial breast irradiation (PBI delivered externally or intraoperatively, may be a viable alternative to conventional whole breast irradiation. Two large, contemporary randomized trials have demonstrated breast intraoperative radiotherapy (IORT to be noninferior to whole breast external beam radiotherapy (EBRT when assessing for ipsilateral breast tumor recurrence in select patients. Additionally, IORT and other PBI techniques are likely to be more widely adopted in the future because they improve patient convenience by offering an accelerated course of treatment. Coupled with these novel techniques for breast radiotherapy (RT are distinct toxicity profiles and unique cosmetic alterations that differ from conventional breast EBRT and have the potential to impact disease surveillance and patient satisfaction. This paper will review the level-one evidence for treatment efficacy as well as important secondary endpoints like RT toxicity, breast cosmesis, quality of life, patient satisfaction, and surveillance mammography following BCT with IORT.

  13. The use of Monte-Carlo codes for treatment planning in external-beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Alan, E.; Nahum, PhD. [Copenhagen University Hospital, Radiation Physics Dept. (Denmark)

    2003-07-01

    Monte Carlo simulation of radiation transport is a very powerful technique. There are basically no exact solutions to the Boltzmann transport equation. Even, the 'straightforward' situation (in radiotherapy) of an electron beam depth-dose distribution in water proves to be too difficult for analytical methods without making gross approximations such as ignoring energy-loss straggling, large-angle single scattering and Bremsstrahlung production. monte Carlo is essential when radiation is transport from one medium into another. As the particle (be it a neutron, photon, electron, proton) crosses the boundary then a new set of interaction cross-sections is simply read in and the simulation continues as though the new medium were infinite until the next boundary is encountered. Radiotherapy involves directing a beam of megavoltage x rays or electrons (occasionally protons) at a very complex object, the human body. Monte Carlo simulation has proved in valuable at many stages of the process of accurately determining the distribution of absorbed dose in the patient. Some of these applications will be reviewed here. (Rogers and al 1990; Andreo 1991; Mackie 1990). (N.C.)

  14. The use of Monte-Carlo codes for treatment planning in external-beam radiotherapy

    International Nuclear Information System (INIS)

    Monte Carlo simulation of radiation transport is a very powerful technique. There are basically no exact solutions to the Boltzmann transport equation. Even, the 'straightforward' situation (in radiotherapy) of an electron beam depth-dose distribution in water proves to be too difficult for analytical methods without making gross approximations such as ignoring energy-loss straggling, large-angle single scattering and Bremsstrahlung production. monte Carlo is essential when radiation is transport from one medium into another. As the particle (be it a neutron, photon, electron, proton) crosses the boundary then a new set of interaction cross-sections is simply read in and the simulation continues as though the new medium were infinite until the next boundary is encountered. Radiotherapy involves directing a beam of megavoltage x rays or electrons (occasionally protons) at a very complex object, the human body. Monte Carlo simulation has proved in valuable at many stages of the process of accurately determining the distribution of absorbed dose in the patient. Some of these applications will be reviewed here. (Rogers and al 1990; Andreo 1991; Mackie 1990). (N.C.)

  15. The results of radiotherapy for T1 glottic cancers; influence of radiation beam energy.

    Directory of Open Access Journals (Sweden)

    Yamamoto M

    1999-04-01

    Full Text Available We analyzed the influence of various parameters on the results of radiotherapy for T1 glottic cancer by assessing the outcomes of 60 patients with this cancer who received definitive radiotherapy between 1985 and 1994. Seven patients were treated with a cobalt-60 unit, and the other 53 with a linear accelerator (26 patients at 3-MV, 10 at 6-MV, and 17 at 10-MV. Of the 17 patients treated at 10-MV, 4 also received part of their treatment with a cobalt-60 unit. The total radiation dose ranged from 56 Gy to 70 Gy (mean, 61 Gy. The total radiation dose of 51 patients (85% was 60 Gy. The factors found to influence local control were the strength of the radiation beam energy and whether or not there was gross tumor invasion of the anterior commissure. The local control rate was 71% in the patients treated with a 10-MV linear accelerator, 56% in those treated with a 6-MV linear accelerator and, 97% in those treated with a cobalt-60 unit or a 3-MV linear accelerator (P = 0.0173. The local control rate was 43% in the patients with gross anterior commissure invasion and 88% in those without (P = 0.0075. We conclude that low energy photon beams are more suitable for the treatment of early glottic cancers, especially if the lesion grossly invades the anterior commissure.

  16. Volumetric Modulated Arc Radiotherapy for Early Stage Non-Small-Cell Lung Carcinoma: Is It Better Than the Conventional Static Beam Intensity Modulated Radiotherapy?

    OpenAIRE

    Vincent Wing Cheung Wu; Man In Pun; Cho Pan Lam; To Wing Mok; Wah Wai Mok

    2014-01-01

    This study compared the performance of volumetric modulated arc therapy (VMAT) techniques: single arc volumetric modulated arc therapy (SA-VMAT) and double arc volumetric modulated arc therapy (DA-VMAT) with the static beam conventional intensity modulated radiotherapy (C-IMRT) for non-small-cell lung carcinoma (NSCLC). Twelve stage I and II NSCLC patients were recruited and their planning CT with contoured planning target volume (PTV) and organs at risk (OARs) was used for planning. Using th...

  17. The Results of Intraoperative Radiotherapy for Stomach Cancer

    International Nuclear Information System (INIS)

    We retrospectively analyzed the long-term results of radical surgery and intraoperative radiation therapy (IORT) in patients with stomach cancer. From 1988 to 1994, 51 patients were treated with curative surgery and IORT. Postoperative external beam radiotherapy (EBRT) was administered to 30 patients, while adjuvant chemotherapy was administered to 35 patients. A dose of 15 Gy was irradiated with a 9 MeV electron beam as the IORT and a median dose of EBRT was 43.2 Gy (range, 7.2 to 45 Gy). The follow-up period ranged from 1-254 months, with a median follow-up period of 64 months. The median age of all the patients was 58 years (range, 30 to 71 years). The distribution of pathologic stage (American Joint Committee on Cancer [AJCC] 2002 tumor-note-metastasis [TNM]) was as follows: 13 stage I (25.5%), 10 stage II (19.6%), 25 stage III (49.0%), and 3 stage IV (5.9%). Distant metastases occurred in 11 patients (10 in the peritoneum and 1 in bone), including one patient with concurrent local recurrence (anastomosis site). The 5-year locoregional control, disease free survival and overall survival rates were 94.7%, 66.5%, and 51.7%, respectively. For the multivariate analysis, age, TNM stage, and EBRT were significant prognostic factors for overall survival, and only TNM stage for disease free survival. We could have achieved a high loco-regional control rate in patients with locally advanced stomach cancer by adding IORT to radical surgery. However, the benefit of IORT on survival remains to be elucidated.

  18. The Results of Intraoperative Radiotherapy for Stomach Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ji Hoon; Kang, Min Kyu; Kim, Myung Se; Kim, Sung Kyu; Yun, Sang Mo; Kim, Sung Hoon [Dept. of Radiation Oncology, Yeungnam University College of Medicine, Daegu (Korea, Republic of)

    2010-11-15

    We retrospectively analyzed the long-term results of radical surgery and intraoperative radiation therapy (IORT) in patients with stomach cancer. From 1988 to 1994, 51 patients were treated with curative surgery and IORT. Postoperative external beam radiotherapy (EBRT) was administered to 30 patients, while adjuvant chemotherapy was administered to 35 patients. A dose of 15 Gy was irradiated with a 9 MeV electron beam as the IORT and a median dose of EBRT was 43.2 Gy (range, 7.2 to 45 Gy). The follow-up period ranged from 1-254 months, with a median follow-up period of 64 months. The median age of all the patients was 58 years (range, 30 to 71 years). The distribution of pathologic stage (American Joint Committee on Cancer [AJCC] 2002 tumor-note-metastasis [TNM]) was as follows: 13 stage I (25.5%), 10 stage II (19.6%), 25 stage III (49.0%), and 3 stage IV (5.9%). Distant metastases occurred in 11 patients (10 in the peritoneum and 1 in bone), including one patient with concurrent local recurrence (anastomosis site). The 5-year locoregional control, disease free survival and overall survival rates were 94.7%, 66.5%, and 51.7%, respectively. For the multivariate analysis, age, TNM stage, and EBRT were significant prognostic factors for overall survival, and only TNM stage for disease free survival. We could have achieved a high loco-regional control rate in patients with locally advanced stomach cancer by adding IORT to radical surgery. However, the benefit of IORT on survival remains to be elucidated.

  19. The international protocol for the dosimetry of external radiotherapy beams based on standards of absorbed dose to water

    International Nuclear Information System (INIS)

    An International Code of Practice (CoP, or dosimetry protocol) for external beam radiotherapy dosimetry based on standards of absorbed dose to water has been published by the IAEA on behalf of IAEA, WHO, PAHO and ESTRO. The CoP provides a systematic and internationally unified approach for the determination of the absorbed dose to water in reference conditions with radiotherapy beams. The development of absorbed-dose-to-water standards for high-energy photons and electrons offers the possibility of reducing the uncertainty in the dosimetry of radiotherapy beams. Many laboratories already provide calibrations at the radiation quality of 60Co gamma-rays and some have extended calibrations to high-energy photon and electron beams. The dosimetry of kilovoltage x-rays, as well as that of proton and ion beams can also be based on these standards. Thus, a coherent dosimetry system based on the same formalism is achieved for practically all radiotherapy beams. The practical use of the CoP as simple. The document is formed by a set of different CoPs for each radiation type, which include detailed procedures and worksheets. All CoPs are based on ND,w chamber calibrations at a reference beam quality Qo, together with radiation beam quality correction factors kQ preferably measured directly for the user's chamber in a standards laboratory. Calculated values of kQ are provided together with their uncertainty estimates. Beam quality specifiers are 60Co, TPR20,10 (high-energy photons), R50 (electrons), HVL and kV (x-rays) and Rres (protons and ions)

  20. Dual source and dual detector arrays tetrahedron beam computed tomography for image guided radiotherapy.

    Science.gov (United States)

    Kim, Joshua; Lu, Weiguo; Zhang, Tiezhi

    2014-02-01

    Cone-beam computed tomography (CBCT) is an important online imaging modality for image guided radiotherapy. But suboptimal image quality and the lack of a real-time stereoscopic imaging function limit its implementation in advanced treatment techniques, such as online adaptive and 4D radiotherapy. Tetrahedron beam computed tomography (TBCT) is a novel online imaging modality designed to improve on the image quality provided by CBCT. TBCT geometry is flexible, and multiple detector and source arrays can be used for different applications. In this paper, we describe a novel dual source-dual detector TBCT system that is specially designed for LINAC radiation treatment machines. The imaging system is positioned in-line with the MV beam and is composed of two linear array x-ray sources mounted aside the electrical portal imaging device and two linear arrays of x-ray detectors mounted below the machine head. The detector and x-ray source arrays are orthogonal to each other, and each pair of source and detector arrays forms a tetrahedral volume. Four planer images can be obtained from different view angles at each gantry position at a frame rate as high as 20 frames per second. The overlapped regions provide a stereoscopic field of view of approximately 10-15 cm. With a half gantry rotation, a volumetric CT image can be reconstructed having a 45 cm field of view. Due to the scatter rejecting design of the TBCT geometry, the system can potentially produce high quality 2D and 3D images with less radiation exposure. The design of the dual source-dual detector system is described, and preliminary results of studies performed on numerical phantoms and simulated patient data are presented.

  1. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning

    Science.gov (United States)

    Thomas, T. Hannah Mary; Devakumar, D.; Purnima, S.; Ravindran, B. Paul

    2009-04-01

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm × 10 cm beam at a gantry angle of 0° and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between ±6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.

  2. The adaptation of megavoltage cone beam CT for use in standard radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, T Hannah Mary; Purnima, S; Ravindran, B Paul [Department of Radiotherapy, Christian Medical College, Vellore (India); Devakumar, D [Department of Nuclear Medicine, Christian Medical College, Vellore (India)], E-mail: paul@cmcvellore.ac.in

    2009-04-07

    Potential areas where megavoltage computed tomography (MVCT) could be used are second- and third-phase treatment planning in 3D conformal radiotherapy and IMRT, adaptive radiation therapy, single fraction palliative treatment and for the treatment of patients with metal prostheses. A feasibility study was done on using MV cone beam CT (CBCT) images generated by proprietary 3D reconstruction software based on the FDK algorithm for megavoltage treatment planning. The reconstructed images were converted to a DICOM file set. The pixel values of megavoltage cone beam computed tomography (MV CBCT) were rescaled to those of kV CT for use with a treatment planning system. A calibration phantom was designed and developed for verification of geometric accuracy and CT number calibration. The distance measured between two marker points on the CBCT image and the physical dimension on the phantom were in good agreement. Point dose verification for a 10 cm x 10 cm beam at a gantry angle of 0{sup 0} and SAD of 100 cm were performed for a 6 MV beam for both kV and MV CBCT images. The point doses were found to vary between {+-}6.1% of the dose calculated from the kV CT image. The isodose curves for 6 MV for both kV CT and MV CBCT images were within 2% and 3 mm distance-to-agreement. A plan with three beams was performed on MV CBCT, simulating a treatment plan for cancer of the pituitary. The distribution obtained was compared with those corresponding to that obtained using the kV CT. This study has shown that treatment planning with MV cone beam CT images is feasible.

  3. Dosimetric Characteristics of Circular 6-MeV X-Ray Beams for Stereotactic Radiotherapy with a Linear Accelerator

    Science.gov (United States)

    Wysocka, A.; Rostkowska, J.; Kania, M.; Bulski, W.; Fijuth, J.

    2000-01-01

    Dosimetric characteristics of 6 MeV circular X-ray beams of diameters ranging from 7.5 to 35.0 mm are reported. The 6-MeV X-ray beam from Clinac 2300CD was formed using additional cylindrical BrainLAB's collimators. The mechanical stability of the entire system was verified. Specific quantities measured include tissue maximum ratios (TMR), beam profiles (off-axis ratios OAR) and relative output factors. Measurements of these parameters were performed in a water phantom using small cylindrical ionization chambers and a diamond detector. Comparison of TMR values measured with the ionization chamber and the diamond detector showed no significant differences. It was shown that the latter yields more accurate results for beam profiles than ionization chambers. The mechanical and dosimetric characteristics of this radiotherapy unit are found to be suitable for stereotactic radiosurgery and radiotherapy.

  4. Cone beam computed tomography guided treatment delivery and planning verification for magnetic resonance imaging only radiotherapy of the brain

    DEFF Research Database (Denmark)

    Edmund, Jens M.; Andreasen, Daniel; Mahmood, Faisal;

    2015-01-01

    Background. Radiotherapy based on MRI only (MRI-only RT) shows a promising potential for the brain. Much research focuses on creating a pseudo computed tomography (pCT) from MRI for treatment planning while little attention is often paid to the treatment delivery. Here, we investigate if cone beam...

  5. Dramatic response of follicular thyroid carcinoma with superior vena cava syndrome and tracheal obstruction to external-beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wilford, M.R.; Chertow, B.S.; Lepanto, P.B.; Leidy, J.W. Jr. (Section of Endocrinology, Marshall University School of Medicine, Huntington, West Virginia (USA))

    1991-06-01

    We report a patient with follicular thyroid carcinoma progressing to superior vena cava (SVC) syndrome and tracheal obstruction despite multiple doses of radioactive iodine therapy but subsequently responding dramatically to external-beam radiotherapy (RT). Although RT is not considered to be the treatment of choice for follicular carcinoma, RT in our patient produced unequivocal improvement of SVC syndrome and tracheal obstruction.

  6. MRI of the prostate after combined radiotherapy (interstitial with external beam irradiation): histopathological correlation

    International Nuclear Information System (INIS)

    Aim: To identify the MRI changes of the prostate after combined (high-dose rate interstitial with external beam) radiotherapy for, localized prostate cancer and to correlate the findings with histology in order to determine the value of MR imaging in the follow-up of these patients. Material and methods: Twenty-three patients underwent MR imaging at 1.5 T between 6 and 24 months after completion of combined radiotherapy. The prostate was imaged with axial and coronal T2-weighted sequences and axial T1-weighted sequences before and after intravenous administration of Gd-DTPA. Quandrant or sextant biopsy was performed in all cases and three patients with proven persistence of the tumor underwent salvage prostatectomy. The MRI findings were compared with the biopsy results or the large-area sections. Results: On T2-weighted images the fibrotically changed peripheral zone was hypointense while persistent tumor tissue showed hyperintensity. Solid tumors were depicted when they had a diameter of 1 cm or more. Persistent tumors of the diffuse multifocal type escaped detection. Contrast-enhanced T1-weighted imaging yielded no additional information. The accuracy in detecting persistent tumor was 74%. Conclusions: Histopathologic changes seen after combined radiotherapy correlate with the findings on T2-weighted MR images. MR imaging cannot replace follow-up by routine biopsy. Its only role is assessing local operability in cases found to have increasing PSA levels during follow-up. Further studies are needed to determine the role of MR imaging in this patient population. (orig.)

  7. EPR dosimetry of radiotherapy photon beams in inhomogeneous media using alanine films.

    Science.gov (United States)

    Osterås, Bjørn Helge; Hole, Eli Olaug; Olsen, Dag Rune; Malinen, Eirik

    2006-12-21

    In the current work, EPR (electron paramagnetic resonance) dosimetry using alanine films (134 microm thick) was utilized for dose measurements in inhomogeneous phantoms irradiated with radiotherapy photon beams. The main phantom material was PMMA, while either Styrofoam or aluminium was introduced as an inhomogeneity. The phantoms were irradiated to a maximum dose of about 30 Gy with 6 or 15 MV photons. The performance of the alanine film dosimeters was investigated and compared to results from ion chamber dosimetry, Monte Carlo simulations and radiotherapy treatment planning calculations. It was found that the alanine film dosimeters had a linear dose response above approximately 5 Gy, while a background signal obscured the response at lower dose levels. For doses between 5 and 60 Gy, the standard deviation of single alanine film dose estimates was about 2%. The alanine film dose estimates yielded results comparable to those from the Monte Carlo simulations and the ion chamber measurements, with absolute differences between estimates in the order of 1-15%. The treatment planning calculations exhibited limited applicability. The current work shows that alanine film dosimetry is a method suitable for estimating radiotherapeutical doses and for dose measurements in inhomogeneous media. PMID:17148820

  8. EPR dosimetry of radiotherapy photon beams in inhomogeneous media using alanine films

    Energy Technology Data Exchange (ETDEWEB)

    Oesteraas, Bjoern Helge [Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Montebello, N-0310 Oslo (Norway); Hole, Eli Olaug [Department of Physics, University of Oslo, PO Box 1048 Blindern, N-0316 Oslo (Norway); Olsen, Dag Rune [Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, N-0310 Oslo (Norway); Malinen, Eirik [Department of Radiation Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, N-0310 Oslo (Norway)

    2006-12-21

    In the current work, EPR (electron paramagnetic resonance) dosimetry using alanine films (134 {mu}m thick) was utilized for dose measurements in inhomogeneous phantoms irradiated with radiotherapy photon beams. The main phantom material was PMMA, while either Styrofoam or aluminium was introduced as an inhomogeneity. The phantoms were irradiated to a maximum dose of about 30 Gy with 6 or 15 MV photons. The performance of the alanine film dosimeters was investigated and compared to results from ion chamber dosimetry, Monte Carlo simulations and radiotherapy treatment planning calculations. It was found that the alanine film dosimeters had a linear dose response above approximately 5 Gy, while a background signal obscured the response at lower dose levels. For doses between 5 and 60 Gy, the standard deviation of single alanine film dose estimates was about 2%. The alanine film dose estimates yielded results comparable to those from the Monte Carlo simulations and the ion chamber measurements, with absolute differences between estimates in the order of 1-15%. The treatment planning calculations exhibited limited applicability. The current work shows that alanine film dosimetry is a method suitable for estimating radiotherapeutical doses and for dose measurements in inhomogeneous media.

  9. Multiobjective optimization with a modified simulated annealing algorithm for external beam radiotherapy treatment planning

    International Nuclear Information System (INIS)

    Inverse planning in external beam radiotherapy often requires a scalar objective function that incorporates importance factors to mimic the planner's preferences between conflicting objectives. Defining those importance factors is not straightforward, and frequently leads to an iterative process in which the importance factors become variables of the optimization problem. In order to avoid this drawback of inverse planning, optimization using algorithms more suited to multiobjective optimization, such as evolutionary algorithms, has been suggested. However, much inverse planning software, including one based on simulated annealing developed at our institution, does not include multiobjective-oriented algorithms. This work investigates the performance of a modified simulated annealing algorithm used to drive aperture-based intensity-modulated radiotherapy inverse planning software in a multiobjective optimization framework. For a few test cases involving gastric cancer patients, the use of this new algorithm leads to an increase in optimization speed of a little more than a factor of 2 over a conventional simulated annealing algorithm, while giving a close approximation of the solutions produced by a standard simulated annealing. A simple graphical user interface designed to facilitate the decision-making process that follows an optimization is also presented

  10. Prostate image-guided radiotherapy by megavolt cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Zucca, Sergio; Carau, Barbara; Solla, Ignazio; Garibaldi, Elisabetta; Farace, Paolo; Lay, Giancarlo; Meleddu, Gianfranco; Gabriele, Pietro [Regional Oncological Hospital, Cagliari (Italy). Dept. of Radiooncology

    2011-08-15

    To test megavolt cone-beam CT (MV-CBCT) in order to evaluate setup errors in prostate radiotherapy. The setup of 9 patients was verified weekly by electronic portal imaging (EPI) and MV-CBCT, both performed in the same treatment session. EPI were compared with digitally reconstructed radiographies (DRRs). MV-CBCTs were matched to simulation CTs by manual registration based on bone markers (BMR), by manual registration based on soft tissues (STR) - rectum, bladder, and seminal vesicles - and by automatic registration (AR) performed by a mutual information algorithm. Shifts were evaluated along the three main axes: anteroposterior (AP), craniocaudal (CC), and laterolateral (LL). Finally, in 4 additional patients showing intraprostatic calcifications, the calcification mismatch error was used to evaluate the three MV-CBCT matching methods. A total of 50 pairs of orthogonal EPIs and 50 MV-CBCTs were analyzed. Assuming an overall tolerance of 2 mm, no significant differences were observed comparing EPI vs BMR in any axis. A significant difference (p < 0.001) was observed along the AP axis comparing EPI vs AR and EPI vs STR. On the calcification data set (22 measures), the calcification mismatch along the AP direction was significantly lower (p < 0.05) after STR than after BMR or AR. Bone markers were not an effective surrogate of the target position and significant differences were observed comparing EPI or BMR vs STR, supporting the assessment of soft tissue position by MVCBs to verify and correct patient setup in prostate radiotherapy. (orig.)

  11. An alternative approach to compensators design for photon beams used in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Jurkovic, S. [University Hospital, Department of Radiotherapy, Physics Division, Kresimirova 42, 51000 Rijeka (Croatia); Zauhar, G. [School of Medicine, Department of Physics, Brace Branchetta 20, 51000 Rijeka (Croatia)], E-mail: gordz@medri.hr; Bistrovic, M. [Hospital for Tumors, Radiotherapy Department, Ilica 272, 10000 Zagreb (Croatia); Faj, D. [University Hospital, Department of Radiotherapy and Oncology, J. Huttlera 4, 31000 Osijek (Croatia); Kaliman, Z. [Faculty of Sciences and Arts, Department of Physics, Omladinska 14, 51000 Rijeka (Croatia); Smilovic Radojcic, D. [University Hospital, Department of Radiotherapy, Physics Division, Kresimirova 42, 51000 Rijeka (Croatia)

    2007-09-21

    The use of compensators in order to achieve desired dose distribution has a long history and is a well-established technique in radiation therapy planning. There are several different calculation methods for determining a compensator's thickness. An alternative method that is based on the Cunningham's modification of Clarkson's method to calculate scattered radiation in beams with an inhomogeneous cross-section is proposed. It is well known that the total dose distribution of radiotherapy photon beam consists of the contributions of the primary beam, attenuated by the tissue layer, and the scattered radiation generated by the primary radiation in single and multiple photon scatter events. The scattered component can be represented as a function of the primary radiation. The central point of our method is the numerical estimation of the primary distribution required to achieve the desired total distribution. Now using the calculated primary distribution, the shape of the modulator could be determined. In this way the contribution of the scattered component is validated in a more accurate way than using effective attenuation coefficients, which is a common practice. The method is verified in various clinical situations and compared with the standard method. The accuracy, although dependent on geometry, was improved by at least 2%. With more complex geometries there is an even higher gain in accuracy with our method when compared to the standard method.

  12. A volumetric approach to path-length measurements is essential when treating radiotherapy with modulated beams

    International Nuclear Information System (INIS)

    The established dosimetric benefits of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy have lead to their increased use in prostate radiotherapy. Complimenting these techniques, volumetric image guidance has supported increased positional accuracy. In addition, 3-dimensional image guidance has also allowed for assessment of potential dosimetric variation that can be attributed to a deformation of either internal or external structures, such as rectal distension or body contour. Compounding these issues is the variation of tissue density through which the new field position passes and also the variation of dose across a modulated beam. Despite the growing level of interest in this area, there are only a limited number of articles that examine the effect of a variation in beam path length, particularly across a modulated field. IMRT and volumetric-modulated radiation therapy (VMAT) fields are dynamic in nature, and the dose gradient within these fields is variable. Assessment of variation of path length away from the beam's central axis and across the entire field is vital where there is considerable variation of dose within the field, such as IMRT and VMAT. In these cases, reliance on the traditional central axis to focus skin distances is no longer appropriate. This article discusses these more subtle challenges that may have a significant clinical effect if left unrecognized and undervalued

  13. A volumetric approach to path-length measurements is essential when treating radiotherapy with modulated beams

    Energy Technology Data Exchange (ETDEWEB)

    Forde, Elizabeth, E-mail: eforde@tcd.ie [Discipline of Radiation Therapy, School of Medicine, Trinity College Dublin, Dublin (Ireland); Booth, Jeremy [Northern Sydney Cancer Centre, Royal North Shore Hospital, New South Wales (Australia); Leech, Michelle [Discipline of Radiation Therapy, School of Medicine, Trinity College Dublin, Dublin (Ireland)

    2014-07-01

    The established dosimetric benefits of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy have lead to their increased use in prostate radiotherapy. Complimenting these techniques, volumetric image guidance has supported increased positional accuracy. In addition, 3-dimensional image guidance has also allowed for assessment of potential dosimetric variation that can be attributed to a deformation of either internal or external structures, such as rectal distension or body contour. Compounding these issues is the variation of tissue density through which the new field position passes and also the variation of dose across a modulated beam. Despite the growing level of interest in this area, there are only a limited number of articles that examine the effect of a variation in beam path length, particularly across a modulated field. IMRT and volumetric-modulated radiation therapy (VMAT) fields are dynamic in nature, and the dose gradient within these fields is variable. Assessment of variation of path length away from the beam's central axis and across the entire field is vital where there is considerable variation of dose within the field, such as IMRT and VMAT. In these cases, reliance on the traditional central axis to focus skin distances is no longer appropriate. This article discusses these more subtle challenges that may have a significant clinical effect if left unrecognized and undervalued.

  14. Optimal beam arrangement for pulmonary ventilation image-guided intensity-modulated radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    The principal aim of this study was to evaluate the feasibility of incorporating four-dimensional (4D)-computed tomography (CT)-based functional information into treatment planning and to evaluate the potential benefits of individualized beam setups to better protect lung functionality in patients with non-small cell lung cancer (NSCLC). Peak-exhale and peak-inhale CT scans were carried out in 16 patients with NSCLC treated with intensity-modulated radiotherapy (IMRT). 4D-CT-based ventilation information was generated from the two sets of CT images using deformable image registration. Four kinds of IMRT plans were generated for each patient: two anatomic plans without incorporation of ventilation information, and two functional plans with ventilation information, using either five equally spaced beams (FESB) or five manually optimized beams (FMOB). The dosimetric parameters of the plans were compared in terms of target and normal tissue structures, with special focus on dose delivered to total lung and functional lung. In both the anatomic and functional plans, the percentages of both the functional and total lung regions irradiated at V5, V10, and V20 (percentage volume irradiated to >5, >10 and >20 Gy, respectively) were significantly lower for FMOB compared with FESB (P < 0.05), but there was no significant difference for V30 (P > 0.05). Compared with FESB, a greater degree of sparing of the functional lung was achieved in functional IMRT plans with optimal beam arrangement, without compromising target volume coverage or the irradiated volume of organs at risk, such as the spinal cord, esophagus, and heart. Pulmonary ventilation image-guided IMRT planning with further optimization of beam arrangements improves the preservation of functional lung in patients with NSCLC

  15. The Role of Dosimetry Audits in Radiotherapy Quality Assurance: Eight Years of Experience in Greek External Beam Radiotherapy and Brachytherapy Centres

    International Nuclear Information System (INIS)

    The Greek Atomic Energy Commission (GAEC) runs dosimetry audits through on-site visits for photon and electron beams and for 192Ir brachytherapy high dose rate systems in all Greek radiotherapy centres. In audits, absolute and relative dosimetry measurements are being performed. The deviation, expressed as the percentage difference of the measured values by the GAEC to the respective stated values by the radiotherapy centre of absorbed dose to water or air kerma strength were recorded and compared to the action levels of ±3% (preventive actions needed) and ±5% (immediate corrective actions needed). The results of the subsequent audit rounds, each one lasting for approximately four years, are presented in this work. During the first round, 79.2% of photon beams exhibited deviations of less than 3%, while during the second round this photon beam percentage increased to 96.9%. During the first round, 76.4% of the electron beams recorded deviations less than 3% and 12.9% higher than 5%. All brachytherapy sources showed deviations less than 3%. An improvement in dose accuracy was recorded during the subsequent rounds of the audits. (author)

  16. Dosimetric properties characterization of silicon diodes used in photon beam radiotherapy

    International Nuclear Information System (INIS)

    In the current work it was studied the performance of epitaxial (EPI) and float zone (FZ) silicon diodes as on-line dosimeters for megavoltage (EPI diode) and orthovoltage (EPI and FZ diode) photon beam radiotherapy. In order to be used as dosimeters the diodes were enclosed in black polymethylmethacrylate (PMMA) probes. The devices were then connected, on photovoltaic mode, to an electrometer Keithley® 6517B to allow measurements of the photocurrent. The irradiations were performed with 6 and 18 MV photon beams (Siemens Primus® linear accelerator), 6 and 15 MV (Novalis TX®) and 10, 25, 30 and 50 kV of a Pantak / Seifert X ray radiation device. During the measurements with the Siemens Primus the diodes were held between PMMA plates placed at 10.0 cm depth. When using Novalis TX® the devices were held between solid water plates placed at 50 cm depth. In both cases the diodes were centered in a radiation field of 10 x 10 cm2, with the source-to-surface distance (SSD) kept at 100 cm. In measurements with orthovoltage photon beams the diodes were placed 50.0 cm from the tube in a radiation field of 8 cm diameter. The dose-rate dependency was studied for 6 and 15 MV (varying the dose-rate from 100 to 600 monitor units per minute) and for the 50 kV beam by varying the current tube from 2 to 20 mA. All devices showed linear response with dose rate and, within uncertainties the charge collected is independent of dose rate. The current signals induced showed good instantaneous repeatability of the diodes, characterized by coefficients of variation of current (CV) smaller than 1.14% (megavoltage beams) and 0.15% for orthovoltage beams and coefficients of variation of charge (CV) smaller than 1.84% (megavoltage beams) and 1.67% (orthovoltage beams). The dose response curves were quite linear with linear correlation coefficients better than 0.9999 for all diodes. (author)

  17. Evaluation of a plane-parallel ionization chamber for low-energy radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana Paula; Neves, Lucio Pereira; Santos, William de Souza; Caldas, Linda V.E., E-mail: aperini@ipen.br, E-mail: lpneves@ipen.br, E-mail: wssantos@ipen.br, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    A plane-parallel ionization chamber, with a sensitive volume of 6.3 cm{sup 3}, developed at the Calibration Laboratory of IPEN (LCI), was utilized to verify the possibility of its application in low-energy X-ray beam qualities for radiotherapy (T-qualities). This homemade ion chamber was manufactured using polymethyl methacrylate (PMMA) coated with graphite, and co-axial cables. In order to evaluate the performance of this ionization chamber, some characterization tests were performed: short- and medium-term stability, leakage current, saturation, ion collection efficiency, polarity effect and linearity of response. The maximum value obtained in the short-term stability test was 0.2%, in accordance with the limit value of 0.3% provided by the IEC 60731 standard. The saturation curve was obtained varying the applied voltage from -400 V to +400 V, in steps of 50 V, using the charge collecting time of 20 s. From the saturation curve two other characteristics were analyzed: the polarity effect and the ion collection efficiency, with results within the international recommendations. The leakage current of the ionization chamber was measured in time intervals of 20 minutes, before and after its irradiations, and all the results obtained were in agreement with the IEC 60731 standard. The linearity of response was verified utilizing the T-50(b) radiation quality, and the ionization chamber was exposed to different air kerma rates. The response of the ionization chamber presented a linear behavior. Therefore, all results were considered satisfactory, within international recommendations, indicating that this homemade ionization chamber presents potential routine use in dosimetry of low-energy radiotherapy beams. (author)

  18. Contribution to the planning and dosimetry of photon beams applied to radiosurgery and stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Radiosurgery and stereotactic radiotherapy are irradiation techniques that use small diameter photon beams for treating intracranial lesions such as pituitary adenomas, acoustic tumors and arterio-venous malformations which are inaccessible for surgery. These treatment techniques are characterized by the use of very small radiation beams which deliver a precisely measured dose to the target volume, while sparing the surrounding healthy tissue. Treatment can be performed by using multiple 60Co gamma-ray sources (in the so-called 'Gamma Knife'), charged particles or X-ray beams produced by linear accelerators. The prescribed dose can be given in a single session or in multiple fractions, as in conventional radiotherapy. The success of the treatment depends, among other factors, of the accurate determination of the parameters that characterize the radiation beam produced by the equipment, as well as, of a well designed quality assurance program. In this study, the dosimetric parameters of a set of collimating cones of a RadionicsTM treatment system applied to two 6 MV- photon beams (Clinac 600C - VarianTM, and Mevatron MD2 - SiemensTM) were evaluated by using a water filled PMMA simulator. Measurements were carried out for photon beam diameters ranging from 12.5 to 40.0 mm for the Clinac-600C and from 5.0 to 50.0 mm for the Mevatron MD2. The parameters were evaluated by using a parallel plate ionization chamber (Markus), Kodak X-Omat V dosimetric films, thermoluminescent dosemeters (Harschaw, TLD-100) and photodiodes. The maximum tissue-ratio, the off-axis profile and the output factors were determined and the results were compared to those reported elsewhere. A study of the dosimetric characteristics of some commercially available phototransistors was also carried out. The results showed that these electronic components can be successfully used for measuring the dosimetric parameters of small diameter photon beans used in radiosurgery. Measurements were also

  19. Development of a diamond dosimeter for measuring the absorbed dose in small beams used in stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Stereotactic radiotherapy is a relatively recent technique used for the treatment of small benign and malignant tumors with small radiation beams. The clinical efficiency of this technique has been proved. However, the measurement of absolute and relative dose in small beams is not possible currently due to the lack of suited detectors for these measurements. In small beam dosimetry, the detector has to be as close as possible to tissue equivalence and exhibit a small detection volume due to the lack of lateral electronic equilibrium. Characteristics of diamond (water equivalent material Z=6, high density) make it an ideal candidate to fulfil most of small beam dosimetry requirements. In this thesis, we developed a dosimeter prototype for small beams, based on CVD synthetic single crystal diamond. The diamond samples were characterized optically and their detection properties were investigated under X-rays and alpha-particles. First diamond dosimeter prototypes were tested with small beams produced by several stereotactic machines. Studies using Monte Carlo simulations were performed in order to optimize the parameters involved in the detector response in small beams. This leaded to a final diamond dosimeter prototype that respects all radiotherapy centers requirements, in both standard and small beams. (author)

  20. On the clinical applicability of large-area 2-D TL dosimetry for verifying small photon radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Kabat, D.; Nahajowski, D.; Gora, E.; Rozwadowska-Bogusz, B.; Lesiak, J.; Polak, B. [Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow Branch, Garncarska 11, 31-115 Krakow (Poland); Czopyk, L.; Olko, P. [Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Krakow (Poland); Waligorski, M.P.R. [Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow Branch, Garncarska 11, 31-115 Krakow (Poland); Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Krakow (Poland)], E-mail: z5waligo@cyf-kr.edu.pl

    2008-02-15

    A two-dimensional (2-D) thermoluminescence (TL) dosimetry system consisting of LiF:Mg,Cu,P (MCP-N)-ETFE (Teflon)-based TL foils and a large-area TLD reader equipped with a CCD camera, has been developed at the Institute of Nuclear Physics (IFJ PAN). At our radiotherapy department we tested the applicability of this system to verify 2-D dose distributions in a multileaf collimator-shaped 6 MV radiotherapy beam of size about 3x3cm{sup 2}. Water-immersible TL foils, of size 50x50mm{sup 2}, c. 0.2 mm thickness and density 1.95g/cm{sup 3} were placed in a water phantom and exposed at different depths, across or along the beam axis, read out using a 2-D TL reader equipped with a CCD camera and processed by reader software, yielding respective beam dose profiles in digital matrix form. We were also able to further process these matrices with the software of the therapy planning system (TPS) which we use routinely for clinical purposes. Satisfactory agreement found between dose distributions measured as percent depth dose or transverse beam profiles at different depths and respective distributions calculated by the TPS, confirms that the 2-D TL dosimetry is a promising technique for quality assurance of radiotherapy beams where steep dose gradients may occur over small field areas.

  1. Whole breast radiotherapy in prone and supine position: is there a place for multi-beam IMRT?

    OpenAIRE

    Mulliez, Thomas; Speleers, Bruno; Madani, Indira; De Gersem, Werner; Veldeman, Liv; De Neve, Wilfried

    2013-01-01

    Background: Early stage breast cancer patients are long-term survivors and finding techniques that may lower acute and late radiotherapy-induced toxicity is crucial. We compared dosimetry of wedged tangential fields (W-TF), tangential field intensity-modulated radiotherapy (TF-IMRT) and multi-beam IMRT (MB-IMRT) in prone and supine positions for whole-breast irradiation (WBI). Methods: MB-IMRT, TF-IMRT and W-TF treatment plans in prone and supine positions were generated for 18 unselected ...

  2. External-beam radiation therapy after surgical resection and intraoperative electron-beam radiation therapy for oligorecurrent gynecological cancer. Long-term outcome

    Energy Technology Data Exchange (ETDEWEB)

    Sole, C.V. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Complutense University, School of Medicine, Madrid (Spain); Instituto de Radiomedicina, Service of Radiation Oncology, Santiago (Chile); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Calvo, F.A. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Complutense University, School of Medicine, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Lozano, M.A.; Gonzalez-Sansegundo, C. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Service of Radiation Oncology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Gonzalez-Bayon, L. [Hospital General Universitario Gregorio Maranon, Service of General Surgery, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Alvarez, A. [Hospital General Universitario Gregorio Maranon, Service of Radiation Oncology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Lizarraga, S. [Hospital General Universitario Gregorio Maranon, Department of Gynecology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute of Research Investigation, Madrid (Spain); Garcia-Sabrido, J.L. [Complutense University, School of Medicine, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Service of General Surgery, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Department of Gynecology, Madrid (Spain)

    2014-02-15

    The goal of the present study was to analyze prognostic factors in patients treated with external-beam radiation therapy (EBRT), surgical resection and intraoperative electron-beam radiotherapy (IOERT) for oligorecurrent gynecological cancer (ORGC). From January 1995 to December 2012, 61 patients with ORGC [uterine cervix (52 %), endometrial (30 %), ovarian (15 %), vagina (3 %)] underwent IOERT (12.5 Gy, range 10-15 Gy), and surgical resection to the pelvic (57 %) and paraaortic (43 %) recurrence tumor bed. In addition, 29 patients (48 %) also received EBRT (range 30.6-50.4 Gy). Survival outcomes were estimated using the Kaplan-Meier method, and risk factors were identified by univariate and multivariate analyses. Median follow-up time for the entire cohort of patients was 42 months (range 2-169 months). The 10-year rates for overall survival (OS) and locoregional control (LRC) were 17 and 65 %, respectively. On multivariate analysis, no tumor fragmentation (HR 0.22; p = 0.03), time interval from primary tumor diagnosis to locoregional recurrence (LRR) < 24 months (HR 4.02; p = 0.02) and no EBRT at the time of pelvic recurrence (HR 3.95; p = 0.02) retained significance with regard to LRR. Time interval from primary tumor to LRR < 24 months (HR 2.32; p = 0.02) and no EBRT at the time of pelvic recurrence (HR 3.77; p = 0.04) showed a significant association with OS after adjustment for other covariates. External-beam radiation therapy at the time of pelvic recurrence, time interval for relapse ≥24 months and not multi-involved fragmented resection specimens are associated with improved LRC in patients with ORGC. As suggested from the present analysis a significant group of ORGC patients could potentially benefit from multimodality rescue treatment. (orig.)

  3. An international randomised controlled trial to compare TARGeted Intraoperative radioTherapy (TARGIT) with conventional postoperative radiotherapy after breast-conserving surgery for women with early-stage breast cancer (the TARGIT-A trial).

    Science.gov (United States)

    Vaidya, Jayant S; Wenz, Frederik; Bulsara, Max; Tobias, Jeffrey S; Joseph, David J; Saunders, Christobel; Brew-Graves, Chris; Potyka, Ingrid; Morris, Stephen; Vaidya, Hrisheekesh J; Williams, Norman R; Baum, Michael

    2016-01-01

    BACKGROUND Based on our laboratory work and clinical trials we hypothesised that radiotherapy after lumpectomy for breast cancer could be restricted to the tumour bed. In collaboration with the industry we developed a new radiotherapy device and a new surgical operation for delivering single-dose radiation to the tumour bed - the tissues at highest risk of local recurrence. We named it TARGeted Intraoperative radioTherapy (TARGIT). From 1998 we confirmed its feasibility and safety in pilot studies. OBJECTIVE To compare TARGIT within a risk-adapted approach with whole-breast external beam radiotherapy (EBRT) over several weeks. DESIGN The TARGeted Intraoperative radioTherapy Alone (TARGIT-A) trial was a pragmatic, prospective, international, multicentre, non-inferiority, non-blinded, randomised (1 : 1 ratio) clinical trial. Originally, randomisation occurred before initial lumpectomy (prepathology) and, if allocated TARGIT, the patient received it during the lumpectomy. Subsequently, the postpathology stratum was added in which randomisation occurred after initial lumpectomy, allowing potentially easier logistics and a more stringent case selection, but which needed a reoperation to reopen the wound to give TARGIT as a delayed procedure. The risk-adapted approach meant that, in the experimental arm, if pre-specified unsuspected adverse factors were found postoperatively after receiving TARGIT, EBRT was recommended. Pragmatically, this reflected how TARGIT would be practised in the real world. SETTING Thirty-three centres in 11 countries. PARTICIPANTS Women who were aged ≥ 45 years with unifocal invasive ductal carcinoma preferably ≤ 3.5 cm in size. INTERVENTIONS TARGIT within a risk-adapted approach and whole-breast EBRT. MAIN OUTCOME MEASURES The primary outcome measure was absolute difference in local recurrence, with a non-inferiority margin of 2.5%. Secondary outcome measures included toxicity and breast cancer-specific and non

  4. Fractionated changes in prostate cancer radiotherapy using cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Tzung-Chi, E-mail: tzungchi.huang@mail.cmu.edu.tw [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan (China); Department of Biomedical Informatics, Asia University, Taichung City, Taiwan (China); Chou, Kuei-Ting [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan (China); Yang, Shih-Neng [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan (China); Department of Biomedical Informatics, Asia University, Taichung City, Taiwan (China); Chang, Chih-Kai [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung City, Taiwan (China); Liang, Ji-An [Department of Radiation Oncology, China Medical University Hospital, Taichung City, Taiwan (China); Zhang, Geoffrey [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States)

    2015-10-01

    The high mobility of the bladder and the rectum causes uncertainty in radiation doses prescribed to patients with prostate cancer who undergo radiotherapy (RT) multifraction treatments. The purpose of this study was to estimate the dose received by the bladder, rectum, and prostate from multifraction treatments using daily cone-beam computed tomography (CBCT). Overall, 28 patients with prostate cancer who planned to receive radiation treatments were enrolled in the study. The acquired CBCT before the treatment delivery was registered with the planning CT to map the dose distribution used in the treatment plan for estimating the received dose during clinical treatment. For all 28 patients with 112 data sets, the mean percentage differences (± standard deviation) in the volume and radiation dose were 44% (± 41) and 18% (± 17) for the bladder, 20% (± 21) and 2% (± 2) for the prostate, and 36% (± 29) and 22% (± 15) for the rectum, respectively. Substantial differences between the volumes and radiation dose and those specified in treatment plans were observed. Besides the use of image-guided RT to improve patient setup accuracy, further consideration of large changes in bladder and rectum volumes is strongly suggested when using external beam radiation for prostate cancer.

  5. Design and test of a scintillation dosimeter for dosimetry measurements of high energy radiotherapy beams

    International Nuclear Information System (INIS)

    This work describes the design and evaluation of the performances of a scintillation dosimeter developed for the dosimetry of radiation beams used in radiotherapy. The dosimeter consists in a small plastic scintillator producing light which is guided by means of a plastic optical fiber towards photodetectors. In addition to scintillation, high energy ionizing radiations produce Cerenkov light both in the scintillator and the optical fiber. Based on a wavelength analysis, we have developed a deconvolution technique to measure the scintillation light in the presence of Cerenkov light. We stress the advantages that are anticipated from plastic scintillator, in particular concerning tissue or water equivalence (mass stopping power, mass attenuation or mass energy absorption coefficients). We show that detectors based on this material have better characteristics than conventional dosimeters such as ionisation chambers or silicon detectors. The deconvolution technique is exposed, as well as the calibration procedure using an ionisation chamber. We have studied the uncertainty of our dosimeter. The electronics noise, the fiber transmission, the deconvolution technique and the calibration errors give an overall combined experimental uncertainty of about 0,5%. The absolute response of the dosimeter is studied by means of depth dose measurements. We show that absolute uncertainty with photons or electrons beams with energies ranging from 4 MeV to 25 MeV is less than ± 1 %. Last, at variance with other devices, our scintillation dosimeter does not need dose correction with depth. (author)

  6. Fractionated changes in prostate cancer radiotherapy using cone-beam computed tomography

    International Nuclear Information System (INIS)

    The high mobility of the bladder and the rectum causes uncertainty in radiation doses prescribed to patients with prostate cancer who undergo radiotherapy (RT) multifraction treatments. The purpose of this study was to estimate the dose received by the bladder, rectum, and prostate from multifraction treatments using daily cone-beam computed tomography (CBCT). Overall, 28 patients with prostate cancer who planned to receive radiation treatments were enrolled in the study. The acquired CBCT before the treatment delivery was registered with the planning CT to map the dose distribution used in the treatment plan for estimating the received dose during clinical treatment. For all 28 patients with 112 data sets, the mean percentage differences (± standard deviation) in the volume and radiation dose were 44% (± 41) and 18% (± 17) for the bladder, 20% (± 21) and 2% (± 2) for the prostate, and 36% (± 29) and 22% (± 15) for the rectum, respectively. Substantial differences between the volumes and radiation dose and those specified in treatment plans were observed. Besides the use of image-guided RT to improve patient setup accuracy, further consideration of large changes in bladder and rectum volumes is strongly suggested when using external beam radiation for prostate cancer

  7. Kilovoltage Rotational External Beam Radiotherapy on a Breast Computed Tomography Platform: A Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    Prionas, Nicolas D.; McKenney, Sarah E. [Department of Radiology, University of California, Davis, Medical Center, Sacramento, California (United States); Stern, Robin L. [Department of Radiation Oncology, University of California, Davis, Medical Center, Sacramento, California (United States); Boone, John M., E-mail: jmboone@ucdavis.edu [Department of Radiology, University of California, Davis, Medical Center, Sacramento, California (United States)

    2012-10-01

    Purpose: To demonstrate the feasibility of a dedicated breast computed tomography (bCT) platform to deliver rotational kilovoltage (kV) external beam radiotherapy (RT) for partial breast irradiation, whole breast irradiation, and dose painting. Methods and Materials: Rotational kV-external beam RT using the geometry of a prototype bCT platform was evaluated using a Monte Carlo simulator. A point source emitting 178 keV photons (approximating a 320-kVp spectrum with 4-mm copper filtration) was rotated around a 14-cm voxelized polyethylene disk (0.1 cm tall) or cylinder (9 cm tall) to simulate primary and primary plus scattered photon interactions, respectively. Simulations were also performed using voxelized bCT patient images. Beam collimation was varied in the x-y plane (1-14 cm) and in the z-direction (0.1-10 cm). Dose painting for multiple foci, line, and ring distributions was demonstrated using multiple rotations with varying beam collimation. Simulations using the scanner's native hardware (120 kVp filtered by 0.2-mm copper) were validated experimentally. Results: As the x-y collimator was narrowed, the two-dimensional dose profiles shifted from a cupped profile with a high edge dose to an increasingly peaked central dose distribution with a sharp dose falloff. Using a 1-cm beam, the cylinder edge dose was <7% of the dose deposition at the cylinder center. Simulations using 120-kVp X-rays showed distributions similar to the experimental measurements. A homogeneous dose distribution (<2.5% dose fluctuation) with a 20% decrease in dose deposition at the cylinder edge (i.e., skin sparing) was demonstrated by weighted summation of four dose profiles using different collimation widths. Simulations using patient bCT images demonstrated the potential for treatment planning and image-guided RT. Conclusions: Rotational kV-external beam RT for partial breast irradiation, dose painting, and whole breast irradiation with skin sparing is feasible on a bCT platform

  8. On the feasibility of dose quantification with in-beam PET data in radiotherapy with 12C and proton beams

    International Nuclear Information System (INIS)

    The physical advantages of light ions in combination with technological advances like intensity controlled raster scanning offer a unique tool for high precision radiotherapy. This is particularly applied to delicate clinical situations of inoperable tumours growing in close proximity to critical organs. The potential benefit of such a high selectivity of ion beam therapy demands the complex and strictly conformal dose delivery to be monitored in-situ and non-invasively in three dimensions. In contrast to conventional photon radiation, light ions exhibit a well defined range which determines the position of the maximum dose delivery in the inhomogeneous tumour target. This requires a monitoring technology along the ion trajectory offering millimetre precision. Additionally, accurate control of the lateral position of the irradiation field within the patient can be a crucial issue for the frequent case of portals passing adjacent to organs at risk. At present, positron emission tomography (PET) represents the only feasible method fulfilling these requirements. For this purpose a dedicated in-beam positron camera has been completely integrated into the experimental heavy ion treatment site at the Gesellschaft fuer Schwerionenforschung (GSI) Darmstadt. This allows to measure the minor amount of β+-activity produced in nuclear reactions between the projectiles and the target nuclei of the tissue simultaneously to the tumour irradiation. The emitted signal is correlated but not directly proportional to the spatial pattern of the delivered dose. Hence, therapy control is achieved by comparing the measured β+-activity distribution with a prediction based on the treatment plan and the specific time course of the particular irradiation. (orig.)

  9. Intraoperative radiotherapy given as a boost for early breast cancer: Long-term clinical and cosmetic results

    International Nuclear Information System (INIS)

    Purpose: The standard radiotherapy (RT) of breast cancer consists of 50 Gy external beam RT (EBRT) to the whole breast followed by an electron boost of 10-16 Gy to the tumor bed, but this has several cosmetic disadvantages. Intraoperative radiotherapy (IORT) could be an alternative to overcome these. Methods and Materials: We evaluated 50 women with early breast cancer operated on in a dedicated IORT facility. Median dose of 10 Gy was delivered using 9-MeV electron beams. All patients received postoperative EBRT (50 Gy in 2 Gy fractions). Late toxicity and cosmetic results were assessed independently by two physicians according to the Common Terminology Criteria for Adverse Event v3.0 grading system and the European Organization for Research and Treatment of Cancer questionnaires. Results: After a median follow-up of 9.1 years (range, 5-15 years), two local recurrences were observed within the primary tumor bed. At the time of analysis, 45 patients are alive with (n = 1) or without disease. Among the 42 disease-free remaining patients, 6 experienced Grade 2 late subcutaneous fibrosis within the boost area. Overall, the scores indicated a very good quality of life and cosmesis was good to excellent in the evaluated patients. Conclusion: Our results confirm that IORT given as a boost after breast-conserving surgery is a reliable alternative to conventional postoperative fractionated boost radiation

  10. Cone-beam computed tomography in hypofractionated stereotactic radiotherapy for brain metastases

    Directory of Open Access Journals (Sweden)

    Ingrosso Gianluca

    2012-04-01

    Full Text Available Abstract Background To assess interfraction translational and rotational setup errors, in patients treated with image-guded hypofractionated stereotactic radiotherapy, immobilized by a thermoplastic mask and a bite-block and positioned using stereotactic coordinates. Methods 37 patients with 47 brain metastases were treated with hypofractionated stererotactic radiotherapy. All patients were immobilized with a combination of a thermoplastic mask and a bite-block fixed to a stereotactic frame support. Daily cone-beam CT scans were acquired for every patient before the treatment session and were matched online with planning CT images, for 3D image registration. The mean value and standard deviation of all translational (X, Y, Z and rotational errors (θx, θy, θz were calculated for the matching results of bone matching algorithm. Results A total of 194 CBCT scans were analyzed. Mean +/- standard deviation of translational errors (X, Y, Z were respectively 0.5 +/- 1.6 mm (range -5.7 and 5.9 mm in X; 0.4 +/- 2.7 mm (range -8.2 and 12.1 mm in Y; 0.4 +/- 1.9 mm (range -7.0 and 14 mm in Z; median and 90th percentile were respectively within 0.5 mm and 2.4 mm in X, 0.3 mm and 3.2 mm in Y, 0.3 mm and 2.2 mm in Z. Mean +/- standard deviation of rotational errors (θx, θy, θz were respectively 0.0 degrees+/- 1.3 degrees (θx (range -6.0 degrees and 3.1 degrees; -0.1 degrees +/- 1.1 degrees (θy (range -3.0 degrees and 2.4 degrees; -0.6 degrees +/- 1.4 degrees (θz (range -5.0 degrees and 3.3 degrees. Median and 90th percentile of rotational errors were respectively within 0.1 degrees and 1.4 degrees (θx, 0.0 degrees and 1.2 degrees (θy, 0.0 degrees and 0.9 degrees (θz. Mean +/- SD of 3D vector was 3.1 +/- 2.1 mm (range 0.3 and 14.9 mm; median and 90th percentile of 3D vector was within 2.7 mm and 5.1 mm. Conclusions Hypofractionated stereotactic radiotherapy have the significant limitation of uncertainty in interfraction repeatability of the patient

  11. Salvage High-intensity Focused Ultrasound for the Recurrent Prostate Cancer after Radiotherapy

    Science.gov (United States)

    Shoji, S.; Nakano, M.; Omata, T.; Harano, Y.; Nagata, Y.; Usui, Y.; Terachi, T.; Uchida, T.

    2010-03-01

    To investigate the use of minimally invasive high-intensity focused ultrasound (HIFU) as a salvage therapy in men with localized prostate cancer recurrence following external beam radiotherapy (EBRT), brachytherapy or proton therapy. A review of 20 cases treated using the Sonablate® 500 HIFU device, between August 28, 2002 and September 1, 2009, was carried out. All men had presumed organ-confined, histologically confirmed recurrent prostate adenocarcinoma following radiation therapy. All men with presumed, organ-confined, recurrent disease following EBRT in 8 patients, brachytherapy in 7 patients or proton therapy in 5 patients treated with salvage HIFU were included. The patients were followed for a mean (range) of 16.0 (3-80) months. Biochemical disease-free survival (bDFS) rates in patients with low-intermediate and high risk groups were 86% and 50%, respectively. Side-effects included urethral stricture in 2 of the 16 patients (13%), urinary tract infection or dysuria syndrome in eight (26%), and urinary incontinence in one (6%). Recto-urethral fistula occurred in one patient (6%). Transrectal HIFU is an effective treatment for recurrence after radiotherapy especially in patients with low- and intermediate risk groups.

  12. Survival of women with clear cell and papillary serous endometrial cancer after adjuvant radiotherapy

    International Nuclear Information System (INIS)

    Type II (papillary serous and clear cell) endometrial carcinoma (EC) is a rare subgroup and is considered to have an unfavorable prognosis. The purpose of this retrospective analysis was to elucidate the meaning of adjuvant radiotherapy (RT) for clinical outcome and to define prognostic factors in these patients (pts). From 2004-2012 forty-two pts with type II EC underwent surgery followed by adjuvant RT at our department. Median age was 72 years. The majority were early stage carcinomas (FIGO I n = 27 [64.3%], FIGO II n = 4 [9.5%], FIGO III n = 11 [26.2%]. Seven pts (16.7%) received adjuvant chemotherapy (ChT). Pts were treated with external beam radiotherapy (EBRT) and brachytherapy (IVB) boost. Five-year local recurrence free survival (LRFS), distant metastases free survival (DMFS) and overall survival (OS) were 85.4%, 78%, and 64.5% respectively. LRFS was better with lower pT stage, without lymphangiosis (L0), without haemangiosis (V0) and negative resection margins (R0). DMFS was prolonged in lymph node negatives (N0), L0, V0 and R0. OS was improved in younger pts, N0, L0, V0 and after lymphadenectomy (LNE). Multivariate analysis revealed haemangiosis (V1) as the only independent prognostic factor for OS (p = .014) and DMFS (p = .008). For LRFS pT stage remained as an independent prognostic factor (p = .028). Adjuvant RT with EBRT/IVB ensures adequate local control in type II EC, but control rates remain lower than in type I EC. A benefit of additional adjuvant ChT could not be demonstrated and a general omission of EBRT cannot be recommended at this point. Lymphovascular infiltration and pT stage might be the best predictive factors for a benefit from combined local and systemic treatment

  13. Integral dose investigation of non-coplanar treatment beam geometries in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dan; Dong, Peng; Ruan, Dan; Low, Daniel A.; Sheng, Ke, E-mail: ksheng@mednet.ucla.edu [Department of Radiation Oncology, University of California, Los Angeles, California 90095 (United States); Long, Troy; Romeijn, Edwin [Department of Industrial and Operations, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-01-15

    Purpose: Automated planning and delivery of non-coplanar plans such as 4π radiotherapy involving a large number of fields have been developed to take advantage of the newly available automated couch and gantry on C-arm gantry linacs. However, there is an increasing concern regarding the potential changes in the integral dose that needs to be investigated. Methods: A digital torso phantom and 22 lung and liver stereotactic body radiation therapy (SBRT) patients were included in the study. The digital phantom was constructed as a water equivalent elliptical cylinder with a major axis length of 35.4 cm and minor axis of 23.6 cm. A 4.5 cm diameter target was positioned at varying depths along the major axis. Integral doses from intensity modulated, non-coplanar beams forming a conical pattern were compared against the equally spaced coplanar beam plans. Integral dose dependence on the phantom geometry and the beam number was also quantified. For the patient plans, the non-coplanar and coplanar beams and fluences were optimized using a column generation and pricing approach and compared against clinical VMAT plans using two full (lung) or partial coplanar arcs (liver) entering at the side proximal to the tumor. Both the average dose to the normal tissue volume and the total volumes receiving greater than 2 Gy (V2) and 5 Gy (V5) were evaluated and compared. Results: The ratio of integral dose from the non-coplanar and coplanar plans depended on the tumor depth for the phantom; for tumors shallower than 10 cm, the non-coplanar integral doses were lower than coplanar integral doses for non-coplanar angles less than 60°. Similar patterns were observed in the patient plans. The smallest non-coplanar integral doses were observed for tumor 6–8 cm deep. For the phantom, the integral dose was independent of the number of beams, consistent with the liver SBRT patients but the lung SBRT patients showed slight increase in the integral dose when more beams were used. Larger

  14. Initial patient imaging with an optimised radiotherapy beam for portal imaging

    International Nuclear Information System (INIS)

    Background and purpose: To investigate the feasibility and the advantages of a portal-imaging mode on a medical accelerator, consisting of a thin low-Z bremsstrahlung target and a thin Gd2O2S/film detector, for patient imaging. Patients and methods: The international code of practice for high-energy photon dosimetry was used to calibrate dosimetry instruments for the imaging beam produced by 4.75 MeV electrons hitting a 6 mm thick aluminium target. Images of the head and neck of a humanoid phantom were taken with a mammography film system and the dose in the phantom was measured with TLDs calibrated for this beam. The first head and neck patient images are compared with conventional images (taken with the treatment beam on a film radiotherapy verification detector). Visibility of structures for six patients was evaluated. Results: Images of the head and neck of a humanoid phantom, taken with both imaging systems showed that the contrast increased dramatically for the new system while the dose required to form an image was less than 10-2 Gy. The patient images taken with the new and the conventional systems showed that air-tissue interfaces were better defined in the new system image. Anatomical structures, visible on both films, are clearer with the new system. Additionally, bony structures, such as vertebrae, were clearly visible only with the new system. The system under evaluation was significantly better for all features in lateral images and most features in anterior images. Conclusions: This pilot study of the new portal imaging system showed the image quality is significantly improved

  15. Matched Cohort Analysis of Outcomes of Definitive Radiotherapy for Prostate Cancer in Human Immunodeficiency Virus-Positive Patients

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, Shannon, E-mail: shannonkahn@yahoo.com [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Jani, Ashesh; Edelman, Scott; Rossi, Peter; Godette, Karen; Landry, Jerome; Anderson, Cynthia [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA (United States)

    2012-05-01

    Purpose: To compare the biochemical outcome and toxicity scores of men with human immunodeficiency virus (HIV) and prostate cancer with a matched control population with negative or unknown HIV status when treated with external-beam radiotherapy (EBRT). Methods and Materials: A single-institution database of men with prostate cancer treated with EBRT from 1999 to 2009 was reviewed. Thirteen men with HIV were identified and matched to 2 control patients according to age, race, T stage, prostate-specific antigen level, Gleason score, RT dose, intensity-modulated RT vs. three-dimensional conformal RT, and whole-pelvis vs. prostate-only RT, for a total of 39 cases. The median follow-up time was 39 months (range, 3-110 months). Results: The 4-year biochemical failure (BF)-free survival rate was 87% in the HIV-positive group vs. 89% in the controls (p = 0.94). Pre- and post-RT viral loads were found to be predictive of BF (p = 0.04 and p = 0.04, respectively). No men with HIV died, whereas 2 in the control group died of causes unrelated to prostate cancer. Acute and chronic genitourinary and gastrointestinal toxicity were less in the HIV-positive patients than in controls (p < 0.001, p < 0.001, p = 0.003, and p < 0.001, respectively). The HIV-positive men experienced an average decline in CD4 count of 193 cells/mm{sup 3}. Conclusions: Our findings suggest that men with HIV treated with EBRT have a similar risk of BF; however, high viral loads may contribute to an increased risk. This analysis supports that HIV-positive men with prostate cancer can be treated with definitive EBRT with similar disease control and toxicity outcomes as in the general population.

  16. Matched Cohort Analysis of Outcomes of Definitive Radiotherapy for Prostate Cancer in Human Immunodeficiency Virus-Positive Patients

    International Nuclear Information System (INIS)

    Purpose: To compare the biochemical outcome and toxicity scores of men with human immunodeficiency virus (HIV) and prostate cancer with a matched control population with negative or unknown HIV status when treated with external-beam radiotherapy (EBRT). Methods and Materials: A single-institution database of men with prostate cancer treated with EBRT from 1999 to 2009 was reviewed. Thirteen men with HIV were identified and matched to 2 control patients according to age, race, T stage, prostate-specific antigen level, Gleason score, RT dose, intensity-modulated RT vs. three-dimensional conformal RT, and whole-pelvis vs. prostate-only RT, for a total of 39 cases. The median follow-up time was 39 months (range, 3–110 months). Results: The 4-year biochemical failure (BF)-free survival rate was 87% in the HIV-positive group vs. 89% in the controls (p = 0.94). Pre- and post-RT viral loads were found to be predictive of BF (p = 0.04 and p = 0.04, respectively). No men with HIV died, whereas 2 in the control group died of causes unrelated to prostate cancer. Acute and chronic genitourinary and gastrointestinal toxicity were less in the HIV-positive patients than in controls (p 3. Conclusions: Our findings suggest that men with HIV treated with EBRT have a similar risk of BF; however, high viral loads may contribute to an increased risk. This analysis supports that HIV-positive men with prostate cancer can be treated with definitive EBRT with similar disease control and toxicity outcomes as in the general population.

  17. Intraoperative radiotherapy for early breast cancer: do health professionals choose convenience or risk?

    International Nuclear Information System (INIS)

    The randomized TARGIT trial comparing experimental intra-operative radiotherapy (IORT) to up to 7 weeks of daily conventional external beam radiotherapy (EBRT) recruited participants in Western Australia between 2003 and 2012. We aimed to understand preferences for this evolving radiotherapy treatment for early breast cancer (EBC) in health professionals, and how they changed over time and in response to emerging data. Preferences for single dose IORT or EBRT for EBC were elicited in 2004 and 2011, together with factors that may be associated with these preferences. Western Australian health professionals working with breast cancer patients were invited to complete a validated, self-administered questionnaire. The questionnaire used hypothetical scenarios and trade-off methodology to determine the maximum increase in risk of local recurrence health professionals were willing to accept in order to have a single dose of IORT in the place of EBRT if they were faced with this decision themselves. Health professional characteristics were similar across the two time points although 2011 included a higher number of nurse (49% vs. 36%) and allied health (10% vs. 4%) participants and a lower number of radiation therapists (17% vs. 32%) compared to 2004. Health professional preferences varied, with 7.5% and 3% judging IORT unacceptable at any risk, 18% and 21% judging IORT acceptable only if offering an equivalent risk, 56% and 59% judging IORT acceptable with a low maximum increase in risk (1-3%) and 19% and 17% judging a high maximum increase in risk acceptable (4-5%), in 2004 and 2011 respectively. A significantly greater number of nurses accepted IORT as a treatment option in 2011. Most Western Australian health professionals working with breast cancer patients are willing to accept an increase in risk of local recurrence in order to replace EBRT with IORT in a hypothetical setting. This finding was consistent over two time points spanning 7 years despite the duration of

  18. A survey of techniques to reduce and manage external beam radiation-induced xerostomia in British oncology and radiotherapy departments

    Energy Technology Data Exchange (ETDEWEB)

    Macknelly, Andrew [Norfolk and Norwich University Hospital (United Kingdom); Day, Jane [Faculty of Health, Wellbeing and Science, University Campus Suffolk, Waterfront Building, Neptune Quay, Ipswich (United Kingdom)], E-mail: j.day@ucs.ac.uk

    2009-11-15

    Xerostomia is the most common side effect of external beam radiotherapy to the head and neck [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et-al. Can dose reduction to one parotid gland prevent xerostomia? - A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy. Clinical Oncology 2006;18(6):497-504.]. A survey was carried out in British oncology departments to determine what treatment regimes, to minimise xerostomia, are used for patients with head-and-neck cancers treated with external beam radiotherapy. A semi-structured questionnaire consisting of both quantitative and qualitative questions was designed that asked departments which of the identified methods they used, why a method might not be currently employed, and whether its use had ever been considered. The study found that there are wide disparities between the techniques employed by oncology departments to avoid and reduce xerostomia in patients with cancers of the head and neck. The National Institute of Clinical Health and Excellence, [National Institute for Clinical Health and Excellence (NICE). Improving outcomes in head and neck cancers: the manual. London: Office of Public Sector Information; 2004.] for example, recommends that patients are given dental care and dietary advice but some departments did not appear to be doing this. Less than half of departments stated that they offer complementary therapies and less than 40% prescribed pilocarpine, a saliva-stimulant. Only two respondents stated that they use amifostine, a radioprotector, during radiotherapy treatment to the head and neck. The results also suggested a move toward using Intensity Modulated Radiotherapy (IMRT) for treating head-and-neck cancers which offers better normal tissue sparing than three-dimensional conformal radiotherapy. [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et al. Can dose reduction to one parotid gland prevent xerostomia

  19. A survey of techniques to reduce and manage external beam radiation-induced xerostomia in British oncology and radiotherapy departments

    International Nuclear Information System (INIS)

    Xerostomia is the most common side effect of external beam radiotherapy to the head and neck [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et-al. Can dose reduction to one parotid gland prevent xerostomia? - A feasibility study for locally advanced head and neck cancer patients treated with intensity-modulated radiotherapy. Clinical Oncology 2006;18(6):497-504.]. A survey was carried out in British oncology departments to determine what treatment regimes, to minimise xerostomia, are used for patients with head-and-neck cancers treated with external beam radiotherapy. A semi-structured questionnaire consisting of both quantitative and qualitative questions was designed that asked departments which of the identified methods they used, why a method might not be currently employed, and whether its use had ever been considered. The study found that there are wide disparities between the techniques employed by oncology departments to avoid and reduce xerostomia in patients with cancers of the head and neck. The National Institute of Clinical Health and Excellence, [National Institute for Clinical Health and Excellence (NICE). Improving outcomes in head and neck cancers: the manual. London: Office of Public Sector Information; 2004.] for example, recommends that patients are given dental care and dietary advice but some departments did not appear to be doing this. Less than half of departments stated that they offer complementary therapies and less than 40% prescribed pilocarpine, a saliva-stimulant. Only two respondents stated that they use amifostine, a radioprotector, during radiotherapy treatment to the head and neck. The results also suggested a move toward using Intensity Modulated Radiotherapy (IMRT) for treating head-and-neck cancers which offers better normal tissue sparing than three-dimensional conformal radiotherapy. [Anand A, Jain J, Negi P, Chaudhoory A, Sinha S, Choudhury P, et al. Can dose reduction to one parotid gland prevent xerostomia

  20. Development and research on the voxelized dose program based on AAPM TG-43 for the brachtherapy combined with EBRT%内外联合照射剂量计算方法的研究

    Institute of Scientific and Technical Information of China (English)

    王彬冰; 狄小云; 李林飞; 毛仙芝; 陈维军; Anupama HA

    2011-01-01

    目的 基于TG-43U1号报告剂量算法开发体元化的铱-192后装剂量计算程序,通过该程序将两个不同治疗计划系统的内外照射计算结果叠加、计算并显示总剂量分布.方法 在开发的后装铱-192剂量计算程序中,根据Nucletron Plato治疗计划系统中读取的后装治疗计划的治疗信息(放射源强度、驻留位置、驻留时间等),重建出参照ADAC治疗计划系统坐标的后装源驻留位置,并重新计算后装治疗计划的三维剂量分布.计算结果经开发的程序转换并输入到ADAC计划系统,在ADAC中重建后装剂量分布并和ADAC外照射计划的剂量分布结果相叠加.结果 根据TG-43U1号报告算法编写的程序剂量计算结果和Nucletron的Plato治疗计划系统得到的计算结果完全一致,误差<0.1%.同时,该计算结果可以在ADAC计划系统上和其他外照射计划进行叠加.结论 笔者编写的铱-192后装剂量计算程序能使不同治疗计划系统的内外照射计算结果叠加,有一定的临床使用价值.%Objective To develop a brachtherapy (BT) dose calculation program based on AAPM TG-43UI formula.With this program we can combine the dose result of external beam radiotherapy (EBRT) and BT together which is calculated by the different treatment planning TPS.Methods BT treatment data, such as source parameter, dwelling position and dwelling time, are retrieved from Nucletron Plato planning system and converted to ADAC planning system coordinate.The BT 3D dose distribution is re-calculated as well.Then the 3D dose distribution is exported to ADAC planning system.In that way, ADAC planning system can display either the EBRT dose or the BT dose and the combined dose can be calculated, displayed and evaluated as well.Results BT dose calculation result of our program which based on AAPM TG-43UI formula is identical with which of Plato (<0.1%).Furthermore, the BT dose can be transfer to the ADAC easily and the dose distributions of

  1. Theoretical aspects of implementation of kilovoltage cone-beam CT onboard linear accelerator for image-guided radiotherapy.

    Science.gov (United States)

    Rodríguez Cordón, Marta; Ferrer Albiach, Carlos

    2009-08-01

    The main objective of image-guided radiation therapy (IGRT) equipment is to reduce and correct inherent errors in external radiotherapy processes. At the present time, there are different IGRT systems available, but here we will refer exclusively to the kilovoltage cone-beam CT onboard linear accelerator (CBkVCT) and the different aspects that, from a clinical point of view, should be taken into consideration before the implementation of this equipment.

  2. GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    OpenAIRE

    Gu, Xuejun; Jelen, Urszula; Li, Jinsheng; Jia, Xun; Jiang, Steve B.

    2011-01-01

    Targeting at the development of an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite size pencil beam (FSPB) algorithm with a 3D-density correction method on GPU. This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework. Dosimetric evaluations against Monte Carlo dose calculations are conducted on 10 IMRT treatment plans (5 head-and-neck cases and 5 lung cases). For all cases, there i...

  3. Sci—Thur PM: Planning and Delivery — 02: Treatment planning workflow for very high-energy electron beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Bazalova, Magdalena; Qu, Bradley; Palma, Bianey; Maxim, Peter; Loo, Billy [Stanford University, Stanford, CA (United States); Hårdemark, Bjorn; Hynning, Elin [RaySearch Laboratories AB, Stockholm (Sweden)

    2014-08-15

    Purpose: To develop treatment planning workflow for rapid radiotherapy delivered with very-high energy electron (VHEE) scanning beam. Methods: VHEE radiotherapy treatment planning was performed by linking Monte Carlo (MC) dose calculations with inverse optimization in a research version of RayStation. In order to study a number of treatment parameters, a Matlab graphical user interface (GUI) for calculation of VHEE beamlet dose was developed. Through the GUI, EGSnrc MC simulations were run for a number of beam energies, number of beams, beamlet spot and grid sizes, and machine bore sizes. VHEE plans for a pediatric patient with a 4.3 cm{sup 3} brain target optimized with spot-scanning algorithm in RayStation were compared to the clinically delivered 6 MV VMAT plan. Results and Discussion: VHEE beam energy had the largest effect on the quality of dose distributions. For the same target dose, the mean doses to critical organs decreased by 10–15% when planned with 100 MeV compared to 60 MeV. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams. While beamlet spacing and bore size had a small effect on VHEE dose distributions, 0.1-3mm beamlet sizes resulted in identical dose distributions. Critical organ doses were by up to 70% lower in the best VHEE plan compared to the clinical 6 MV VMAT plan. Conclusions: We have developed a GUI for MC beamlet generation for treatment planning of VHEE radiotherapy. We have demonstrated that pediatric VHEE plans resulted in significant critical organ dose sparing compared to the clinical VMAT plan.

  4. Optimization of leaf margins for lung stereotactic body radiotherapy using a flattening filter-free beam

    Energy Technology Data Exchange (ETDEWEB)

    Wakai, Nobuhide, E-mail: wakai@naramed-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan and Department of Radiation Oncology, Nara Medical University, Kashihara, Nara 634-8522 (Japan); Sumida, Iori; Otani, Yuki; Suzuki, Osamu; Seo, Yuji; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Hasegawa, Masatoshi [Department of Radiation Oncology, Nara Medical University, Kashihara, Nara 634-8522 (Japan)

    2015-05-15

    Purpose: The authors sought to determine the optimal collimator leaf margins which minimize normal tissue dose while achieving high conformity and to evaluate differences between the use of a flattening filter-free (FFF) beam and a flattening-filtered (FF) beam. Methods: Sixteen lung cancer patients scheduled for stereotactic body radiotherapy underwent treatment planning for a 7 MV FFF and a 6 MV FF beams to the planning target volume (PTV) with a range of leaf margins (−3 to 3 mm). Forty grays per four fractions were prescribed as a PTV D95. For PTV, the heterogeneity index (HI), conformity index, modified gradient index (GI), defined as the 50% isodose volume divided by target volume, maximum dose (Dmax), and mean dose (Dmean) were calculated. Mean lung dose (MLD), V20 Gy, and V5 Gy for the lung (defined as the volumes of lung receiving at least 20 and 5 Gy), mean heart dose, and Dmax to the spinal cord were measured as doses to organs at risk (OARs). Paired t-tests were used for statistical analysis. Results: HI was inversely related to changes in leaf margin. Conformity index and modified GI initially decreased as leaf margin width increased. After reaching a minimum, the two values then increased as leaf margin increased (“V” shape). The optimal leaf margins for conformity index and modified GI were −1.1 ± 0.3 mm (mean ± 1 SD) and −0.2 ± 0.9 mm, respectively, for 7 MV FFF compared to −1.0 ± 0.4 and −0.3 ± 0.9 mm, respectively, for 6 MV FF. Dmax and Dmean for 7 MV FFF were higher than those for 6 MV FF by 3.6% and 1.7%, respectively. There was a positive correlation between the ratios of HI, Dmax, and Dmean for 7 MV FFF to those for 6 MV FF and PTV size (R = 0.767, 0.809, and 0.643, respectively). The differences in MLD, V20 Gy, and V5 Gy for lung between FFF and FF beams were negligible. The optimal leaf margins for MLD, V20 Gy, and V5 Gy for lung were −0.9 ± 0.6, −1.1 ± 0.8, and −2.1 ± 1.2 mm, respectively, for 7 MV FFF compared

  5. Second cancer incidence risk estimates using BEIR VII models for standard and complex external beam radiotherapy for early breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, E. M.; James, H.; Bonora, M.; Yarnold, J. R.; Evans, P. M. [Joint Department of Physics, Royal Marsden NHS Foundation Trust and Institute of Cancer Research, Sutton SM2 5PT (United Kingdom); Physics Department, Ipswich Hospital NHS Foundation Trust, Ipswich IP4 5PD (United Kingdom); Department of Academic Radiotherapy, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton SM2 5PT, United Kingdom and School of Radiotherapy, University of Milan, Milan 20122 (Italy); Department of Academic Radiotherapy, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Sutton SM2 5PT (United Kingdom); Centre for Vision Speech and Signal Processing, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2012-10-15

    Purpose: To compare organ specific cancer incidence risks for standard and complex external beam radiotherapy (including cone beam CT verification) following breast conservation surgery for early breast cancer.Method: Doses from breast radiotherapy and kilovoltage cone beam CT (CBCT) exposures were obtained from thermoluminescent dosimeter measurements in an anthropomorphic phantom in which the positions of radiosensitive organs were delineated. Five treatment deliveries were investigated: (i) conventional tangential field whole breast radiotherapy (WBRT), (ii) noncoplanar conformal delivery applicable to accelerated partial beast irradiation (APBI), (iii) two-volume simultaneous integrated boost (SIB) treatment, (iv) forward planned three-volume SIB, and (v) inverse-planned three volume SIB. Conformal and intensity modulated radiotherapy methods were used to plan the complex treatments. Techniques spanned the range from simple methods appropriate for patient cohorts with a low cancer recurrence risk to complex plans relevant to cohorts with high recurrence risk. Delineated organs at risk included brain, salivary glands, thyroid, contralateral breast, left and right lung, esophagus, stomach, liver, colon, and bladder. Biological Effects of Ionizing Radiation (BEIR) VII cancer incidence models were applied to the measured mean organ doses to determine lifetime attributable risk (LAR) for ages at exposure from 35 to 80 yr according to radiotherapy techniques, and included dose from the CBCT imaging. Results: All LAR decreased with age at exposure and were lowest for brain, thyroid, liver, and bladder (<0.1%). There was little dependence of LAR on radiotherapy technique for these organs and for colon and stomach. LAR values for the lungs for the three SIB techniques were two to three times those from WBRT and APBI. Uncertainties in the LAR models outweigh any differences in lung LAR between the SIB methods. Constraints in the planning of the SIB methods ensured that

  6. Nondosimetric quality assurance of radiotherapy treatment planning system using multi-leaf collimator beam geometry phantom

    International Nuclear Information System (INIS)

    Radiotherapy treatment planning system (RTPS) plays an important role in overall treatment delivery process. Nondosimetric quality assurance (QA) of the RTPS was carried out to assess the accuracy of nondosimetric parameters of the RTPS for regular/irregular fields obtained with jaws/multi-leaf collimator (MLC) using a dedicated MLC beam geometry phantom. Simulated radiation beams of field sizes 1 x 2 cm, 10 x 10 cm and 15 x 15 cm were created in RTPS using jaws for combinations of (i) 0° couch and gantry angles, and (ii) 323° gantry and 204° couch angles on computed tomography (CT) images of the phantom. Digitally reconstructed radiographs (DRR) for these setups were also generated. MLC co-ordinates were set in the RTPS corresponding to preset irregular field (formed by over travel of A or B bank of leaves) and resulting leaves positions were manually adjusted to fit the structures provided in the phantom. The dimensions of known geometries were measured and compared against the actual dimensions. The variation in measured and expected values of field sizes created by jaws was within 1.8 mm. In the case of DRR for 0° couch and gantry angles, the variation ranged from - 2.7 mm to 1.7 mm and for 204° couch and 323° gantry angles it was in the range of - 1.5-1.3 mm. The maximum variation between set leaf positions and manually adjusted positions for irregular field of MLC were found in the range of 2-4 mm. Nondosimetric QA of an RTPS was carried out, and results of the test provide confidence for its safe use for clinical practice. (author)

  7. Fractionated External Beam Radiotherapy as a Suitable Preparative Regimen for Hepatocyte Transplantation After Partial Hepatectomy

    International Nuclear Information System (INIS)

    Purpose: Hepatocyte transplantation is strongly considered to be a promising option to correct chronic liver failure through repopulation of the diseased organ. We already reported on extensive liver repopulation by hepatocytes transplanted into rats preconditioned with 25-Gy single dose selective external beam irradiation (IR). Herein, we tested lower radiation doses and fractionated protocols, which would be applicable in clinical use. Methods and Material: Livers of dipeptidylpeptidase IV (DPPIV)-deficient rats were preconditioned with partial liver external beam single dose IR at 25 Gy, 8 Gy, or 5 Gy, or fractionated IR at 5 x 5 Gy or 5 x 2 Gy. Four days after completion of IR, a partial hepatectomy (PH) was performed to resect the untreated liver section. Subsequently, 12 million wild-type (DPPIV+) hepatocytes were transplanted via the spleen into the recipient livers. The degree of donor cell integration and liver repopulation was studied 16 weeks after transplantation by means of immunofluorescence and DPPIV-luminescence assay. Results: Donor hepatocyte integration and liver repopulation were more effective in the irradiated livers following pretreatment with the IR doses 1 x 25 Gy and 5 x 5 Gy (formation of large DPPIV-positive cell clusters) than single-dose irradiation at 8 Gy or 5 Gy (DPPIV-positive clusters noticeably smaller and less frequent). Quantitative analysis of extracted DPPIV revealed signals exceeding the control level in all transplanted animals treated with IR and PH. Compared with the standard treatment of 1 x 25 Gy, fractionation with 5 x 5 Gy was equally efficacious, the Mann-Whitney U test disclosing no statistically significant difference (p = 0.146). The lower doses of 1 x 5 Gy, 1 x 8 Gy, and 5 x 2 Gy were significantly less effective with p < 0.05. Conclusion: This study suggests that fractionated radiotherapy in combination with PH is a conceivable pretreatment approach to prime the host liver for hepatocyte transplantation, thus

  8. An advanced rectal carcinoma treated with radical radiotherapy using a proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Miyo, Yasushi; Koyama, Shohei; Kobayashi, S. (Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine) (and others)

    1991-07-01

    The authors present the case of a 72-year-old man admitted to hospital because of anal bleeding. A barium enema and subsequent endoscopic studies revealed a Borrmann type 3, well-differentiated adenocarcinoma of the rectum, with marked narrowing at the Rb to Ra region. On the basis of CT scans, a metastasis to the regional lymph nodes and the softer fatty tissue in the pelvic space was suspected. As surgery was contraindicated since an abnormal antibody against the erythrocytes was detected in the patient's blood, radical radiotherapy was pursued to cure the rectal cancer. Thus, a 250 MeV proton beam was administered to the primary lesion, and a total dose of 90 Gy was delivered in 28 fractions of 3 to 4 Gy daily over 64 days. In addition, X-ray therapy, using a 12 MV linear accelerator and a total dose of 50.4 Gy in 28 fractions of 1.8 Gy, was used for the treatment of a regional lymph node metastasis in the pelvic space. Three years and five months later, the patient died of an occlusive ileus of the rectum. On autopsy, the rectum revealed organized cicatricial fibrosis with marked stenosis. Further, the histological findings of the irradiated tumor cells showed massive fibrosis and hyalinized connective tissue. Vital cancer cells only were found in small parts of the primary rectal lesion, and the biological significance of these small clusters of vital tumor cells is discussed. Finally, neither a regional lymph node metastasis nor a distant metastasis, i.e., to the liver and/or lung, were observed. In conclusion, proton beam therapy was seen to have a beneficial effect on this rectal cancer and on the local control of the disease. (author).

  9. Malignant obstructive jaundice: treatment with external-beam and intracavitary radiotherapy

    International Nuclear Information System (INIS)

    Eleven patients with obstructive jaundice from unresectable cholangiocarcinoma, metastatic porta hepatis adenopathy, or direct compression from a pancreatic malignancy were treated at the Stanford University Medical Center from 1978-1983 with an external drainage procedure followed by high-dose external-beam radiotherapy and by an intracavitary boost to the site of obstruction with Iridium192 (Ir192). A median dose of 5000 cGy was delivered with 4-6 Mv photons to the tumor bed and regional lymphatics in 9 patients, 1 patient received 2100 cGy to the liver in accelerated fractions because of extensive intrahepatic disease, and 1 patient received 7000 equivalent cGy to his pancreatic tumor bed and regional lymphatics with neon heavy particles. An Ir192 wire source later delivered a 3100-10,647 cGy boost to the site of biliary obstruction in each patient, for a mean combined dose of 10,202 cGy to a point 5 mm from the line source. Few acute complications were noted, but 3/11 patients (27%) subsequently developed upper gastrointestinal bleeding from duodenitis or frank duodenal ulceration 4 weeks, 4 months, and 7.5 months following treatment. Eight patients died - 5 with local recurrence +/- distant metastasis, 2 with sepsis, and 1 with widespread systemic metastasis. Autopsies revealed no evidence of biliary tree obstruction in 3/3 patients. Evolution of radiation treatment technqiues for biliary obstruction in the literature is reviewed. High-dose external-beam therapy followed by high-dose Ir192 intracavitary boost is well tolerated and provides significant palliation

  10. Malignant obstructive jaundice: treatment with external-beam and intracavitary radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, D.W.; Safai, C.; Goffinet, D.R.

    1985-02-01

    Eleven patients with obstructive jaundice from unresectable cholangiocarcinoma, metastatic porta hepatis adenopathy, or direct compression from a pancreatic malignancy were treated at the Stanford University Medical Center from 1978-1983 with an external drainage procedure followed by high-dose external-beam radiotherapy and by an intracavitary boost to the site of obstruction with Iridium/sup 192/ (Ir/sup 192/). A median dose of 5000 cGy was delivered with 4-6 Mv photons to the tumor bed and regional lymphatics in 9 patients, 1 patient received 2100 cGy to the liver in accelerated fractions because of extensive intrahepatic disease, and 1 patient received 7000 equivalent cGy to his pancreatic tumor bed and regional lymphatics with neon heavy particles. An Ir/sup 192/ wire source later delivered a 3100-10,647 cGy boost to the site of biliary obstruction in each patient, for a mean combined dose of 10,202 cGy to a point 5 mm from the line source. Few acute complications were noted, but 3/11 patients (27%) subsequently developed upper gastrointestinal bleeding from duodenitis or frank duodenal ulceration 4 weeks, 4 months, and 7.5 months following treatment. Eight patients died - 5 with local recurrence +/- distant metastasis, 2 with sepsis, and 1 with widespread systemic metastasis. Autopsies revealed no evidence of biliary tree obstruction in 3/3 patients. Evolution of radiation treatment technqiues for biliary obstruction in the literature is reviewed. High-dose external-beam therapy followed by high-dose Ir/sup 192/ intracavitary boost is well tolerated and provides significant palliation.

  11. A review of setup error in supine breast radiotherapy using cone-beam computed tomography.

    Science.gov (United States)

    Batumalai, Vikneswary; Holloway, Lois; Delaney, Geoff P

    2016-01-01

    Setup error in breast radiotherapy (RT) measured with 3-dimensional cone-beam computed tomography (CBCT) is becoming more common. The purpose of this study is to review the literature relating to the magnitude of setup error in breast RT measured with CBCT. The different methods of image registration between CBCT and planning computed tomography (CT) scan were also explored. A literature search, not limited by date, was conducted using Medline and Google Scholar with the following key words: breast cancer, RT, setup error, and CBCT. This review includes studies that reported on systematic and random errors, and the methods used when registering CBCT scans with planning CT scan. A total of 11 relevant studies were identified for inclusion in this review. The average magnitude of error is generally less than 5mm across a number of studies reviewed. The common registration methods used when registering CBCT scans with planning CT scan are based on bony anatomy, soft tissue, and surgical clips. No clear relationships between the setup errors detected and methods of registration were observed from this review. Further studies are needed to assess the benefit of CBCT over electronic portal image, as CBCT remains unproven to be of wide benefit in breast RT. PMID:27311516

  12. The Effect of the Size of Radiotherapy Photon Beams on the Absorbed Dose to an Al2O3 Dosimeter

    Institute of Scientific and Technical Information of China (English)

    陈少文; 张文澜; 范丽仙; 唐强; 刘小伟

    2012-01-01

    The effect of the size of radiotherapy photon beams on the absorbed dose to an Al2O3 dosimeter was investigated using the Monte Carlo method. The EGSnrc/DOSRZnrc program code was used to simulate the absorbed dose to the Al2O3 dosimeter, as well as the absorbed dose to water at the corresponding position in the absence of the dosimeter. The incident beams were 60Co γ and 6 MV with a different beam radius ranging from 0.1 cm to 2 cm. Results revealed that the absorbed dose ratio factor depends on the size of the incident photon beam. When the radius of the incident beam is smaller than that of the dosimeter, the absorbed dose ratio factor decreases as the incident beam size increases. The absorbed dose ratio factor reaches its minimum when the radius of the incident beam is almost the same as that of the dosimeter. When the radius of the incident beam is larger than that of the dosimeter, the absorbed dose ratio factor increases as the incident beam size increases. The maximum difference among these absorbed dose ratio factors can be up to 14% in 60Co γ beams and 23% in 6 MV beams. However, when the size of the incident beam is much larger than that of the dosimeter, the effect of the incident beam size on the absorbed dose ratio factor becomes quite small. The maximum discrepancy between the absorbed dose ratio factors and the average value is not more than 1%.

  13. Optical eye tracking system for real-time noninvasive tumor localization in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Via, Riccardo, E-mail: riccardo.via@polimi.it; Fassi, Aurora; Fattori, Giovanni [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano 20133 (Italy); Fontana, Giulia; Pella, Andrea; Tagaste, Barbara; Ciocca, Mario [CNAO Centro Nazionale di Adroterapia Oncologica, Pavia 27100 (Italy); Riboldi, Marco; Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano 20133, Italy and CNAO Centro Nazionale di Adroterapia Oncologica, Pavia 27100 (Italy); Orecchia, Roberto [CNAO Centro Nazionale di Adroterapia Oncologica, Pavia 27100, Italy and European Institute of Oncology, Milano 20141 (Italy)

    2015-05-15

    Purpose: External beam radiotherapy currently represents an important therapeutic strategy for the treatment of intraocular tumors. Accurate target localization and efficient compensation of involuntary eye movements are crucial to avoid deviations in dose distribution with respect to the treatment plan. This paper describes an eye tracking system (ETS) based on noninvasive infrared video imaging. The system was designed for capturing the tridimensional (3D) ocular motion and provides an on-line estimation of intraocular lesions position based on a priori knowledge coming from volumetric imaging. Methods: Eye tracking is performed by localizing cornea and pupil centers on stereo images captured by two calibrated video cameras, exploiting eye reflections produced by infrared illumination. Additionally, torsional eye movements are detected by template matching in the iris region of eye images. This information allows estimating the 3D position and orientation of the eye by means of an eye local reference system. By combining ETS measurements with volumetric imaging for treatment planning [computed tomography (CT) and magnetic resonance (MR)], one is able to map the position of the lesion to be treated in local eye coordinates, thus enabling real-time tumor referencing during treatment setup and irradiation. Experimental tests on an eye phantom and seven healthy subjects were performed to assess ETS tracking accuracy. Results: Measurements on phantom showed an overall median accuracy within 0.16 mm and 0.40° for translations and rotations, respectively. Torsional movements were affected by 0.28° median uncertainty. On healthy subjects, the gaze direction error ranged between 0.19° and 0.82° at a median working distance of 29 cm. The median processing time of the eye tracking algorithm was 18.60 ms, thus allowing eye monitoring up to 50 Hz. Conclusions: A noninvasive ETS prototype was designed to perform real-time target localization and eye movement monitoring

  14. Optical eye tracking system for real-time noninvasive tumor localization in external beam radiotherapy

    International Nuclear Information System (INIS)

    Purpose: External beam radiotherapy currently represents an important therapeutic strategy for the treatment of intraocular tumors. Accurate target localization and efficient compensation of involuntary eye movements are crucial to avoid deviations in dose distribution with respect to the treatment plan. This paper describes an eye tracking system (ETS) based on noninvasive infrared video imaging. The system was designed for capturing the tridimensional (3D) ocular motion and provides an on-line estimation of intraocular lesions position based on a priori knowledge coming from volumetric imaging. Methods: Eye tracking is performed by localizing cornea and pupil centers on stereo images captured by two calibrated video cameras, exploiting eye reflections produced by infrared illumination. Additionally, torsional eye movements are detected by template matching in the iris region of eye images. This information allows estimating the 3D position and orientation of the eye by means of an eye local reference system. By combining ETS measurements with volumetric imaging for treatment planning [computed tomography (CT) and magnetic resonance (MR)], one is able to map the position of the lesion to be treated in local eye coordinates, thus enabling real-time tumor referencing during treatment setup and irradiation. Experimental tests on an eye phantom and seven healthy subjects were performed to assess ETS tracking accuracy. Results: Measurements on phantom showed an overall median accuracy within 0.16 mm and 0.40° for translations and rotations, respectively. Torsional movements were affected by 0.28° median uncertainty. On healthy subjects, the gaze direction error ranged between 0.19° and 0.82° at a median working distance of 29 cm. The median processing time of the eye tracking algorithm was 18.60 ms, thus allowing eye monitoring up to 50 Hz. Conclusions: A noninvasive ETS prototype was designed to perform real-time target localization and eye movement monitoring

  15. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization

    International Nuclear Information System (INIS)

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 50 around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed.

  16. The use of electron beams in radiotherapy: 1st e-learning course in Latin America

    International Nuclear Information System (INIS)

    Full text: Radiotherapy in Brazil has now about 80 linear accelerators with electron beams. Due to the continental dimensions of the country, training of medical physicists is still a problem, because many of these physicists are far from the main training centers (Rio de Janeiro and Sao Paulo) and cannot afford to spend any time there. In other cases, they cannot leave the work since there are not enough physicists at their hospital. Then, the Quality Assurance Programme of the National Cancer Institute, whose mission is to improve the quality of the radiotherapeutic treatments in Brazil, decided to create its 1st e-learning course to help the medical physicists perform a correct electron beam dosimetry, according to the IAEA TRS-398 and quality control tests based on the IAEA-TECDOC-1151. The course had the collaboration of the Public Health National School (Fiocruz) and covers the following subjects: 1) therapeutic linear accelerator electron beams: history, production and clinical application, 2) dosimetric equipment and calibration methods, 3) quality control. It is a 60 hour course, totally at a distance and pedagogically based on the basic principle of constructivism. It is the 1st course on the subject and under this model in Brazil and all Latin America. The students receive a high quality book and CD-ROM (with all the material of the course, including four films with the dosimetric measurements in practice). They also count on full time tutors specially trained in a virtual environment, through which they can communicate with the tutors and among themselves, access a virtual library and participate in special forums. By the end of each subject of the course, the students have to answer questions or perform measurements, which are evaluated by the tutors (receiving specific degrees). The course has been announced during only two weeks. We received 161 registrations. Five times more than anticipated. We selected 81 candidates that have been divided in four

  17. Treatment planning considerations in contrast-enhanced radiotherapy: energy and beam aperture optimization

    Energy Technology Data Exchange (ETDEWEB)

    Garnica-Garza, H M, E-mail: hgarnica@cinvestav.mx [Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional Unidad Monterrey, Via del Conocimiento 201 Parque de Investigacion e Innovacion Tecnologica, Apodaca NL CP 66600 (Mexico)

    2011-01-21

    It has been shown that the use of kilovoltage x-rays in conjunction with a contrast agent incorporated into the tumor can lead to acceptable treatment plans with regard to the absorbed dose distribution produced in the target as well as in the tissue and organs at risk surrounding it. In this work, several key aspects related to the technology and irradiation techniques necessary to clinically implement this treatment modality are addressed by means of Monte Carlo simulation. The Zubal phantom was used to model a prostate radiotherapy treatment, a challenging site due to the depth of the prostate and the presence of bony structures that must be traversed by the x-ray beam on its way to the target. It is assumed that the concentration levels of the enhancing agent present in the tumor are at or below 10 mg per 1 g of tissue. The Monte Carlo code PENELOPE was used to model a commercial x-ray tube having a tungsten target. X-ray energy spectra for several combinations of peak electron energy and added filtration were obtained. For each energy spectrum, a treatment plan was calculated, with the PENELOPE Monte Carlo code, by modeling the irradiation of the patient as 72 independent conformal beams distributed at intervals of 5{sup 0} around the phantom in order to model a full x-ray source rotation. The Cimmino optimization algorithm was then used to find the optimum beam weight and energy for different treatment strategies. It is shown that for a target dose prescription of 72 Gy covering the whole tumor, the maximum rectal wall and bladder doses are kept below 52 Gy for the largest concentration of contrast agent of 10 mg per 1 g of tissue. It is also shown that concentrations of as little as 5 mg per 1 g of tissue also render dose distributions with excellent sparing of the organs at risk. A treatment strategy to address the presence of non-uniform distributions of the contrast agent in the target is also modeled and discussed.

  18. Fifteen-Year Radiotherapy Outcomes of the Randomized PORTEC-1 Trial for Endometrial Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Creutzberg, Carien L., E-mail: c.l.creutzberg@lumc.nl [Department of Clinical Oncology, Leiden University Medical Center (Netherlands); Nout, Remi A. [Department of Clinical Oncology, Leiden University Medical Center (Netherlands); Lybeert, Marnix L.M. [Department of Radiotherapy, Catharina Hospital Eindhoven (Netherlands); Warlam-Rodenhuis, Carla C. [Department of Radiation Oncology, University Medical Center Utrecht (Netherlands); Jobsen, Jan J. [Department of Radiotherapy, Medisch Spectrum Twente, Enschede (Netherlands); Mens, Jan-Willem M. [Department of Radiation Oncology, ErasmusMC-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Lutgens, Ludy C.H.W. [MAASTRO clinic, Maastricht (Netherlands); Pras, Elisabeth [Department of Radiotherapy, University Medical Center Groningen (Netherlands); Poll-Franse, Lonneke V. van de [Comprehensive Cancer Centre South, Eindhoven and Center of Research on Psychology in Somatic Diseases, Tilburg University (Netherlands); Putten, Wim L.J. van [Department of Biostatistics, ErasmusMC-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)

    2011-11-15

    Purpose: To evaluate the very long-term results of the randomized Post Operative Radiation Therapy in Endometrial Carcinoma (PORTEC)-1 trial for patients with Stage I endometrial carcinoma (EC), focusing on the role of prognostic factors for treatment selection and the long-term risk of second cancers. Patients and Methods: The PORTEC trial (1990-1997) included 714 patients with Stage IC Grade 1-2 or Stage IB Grade 2-3 EC. After surgery, patients were randomly allocated to external-beam pelvic radiotherapy (EBRT) or no additional treatment (NAT). Analysis was by intention to treat. Results: 426 patients were alive at the date of analysis. The median follow-up time was 13.3 years. The 15-year actuarial locoregional recurrence (LRR) rates were 6% for EBRT vs. 15.5% for NAT (p < 0.0001). The 15-year overall survival was 52% vs. 60% (p = 0.14), and the failure-free survival was 50% vs. 54% (p = 0.94). For patients with high-intermediate risk criteria, the 15-year overall survival was 41% vs. 48% (p = 0.51), and the 15-year EC-related death was 14% vs. 13%. Most LRR in the NAT group were vaginal recurrences (11.0% of 15.5%). The 15-year rates of distant metastases were 9% vs. 7% (p = 0.25). Second primary cancers had been diagnosed over 15 years in 19% of all patients, 22% vs. 16% for EBRT vs. NAT (p = 0.10), with observed vs. expected ratios of 1.6 (EBRT) and 1.2 (NAT) compared with a matched population (p = NS). Multivariate analysis confirmed the prognostic significance of Grade 3 for LRR (hazard ratio [HR] 3.4, p = 0.0003) and for EC death (HR 7.3, p < 0.0001), of age >60 (HR 3.9, p = 0.002 for LRR and 2.7, p = 0.01 for EC death) and myometrial invasion >50% (HR 1.9, p = 0.03 and HR 1.9, p = 0.02). Conclusions: The 15-year outcomes of PORTEC-1 confirm the relevance of HIR criteria for treatment selection, and a trend for long-term risk of second cancers. EBRT should be avoided in patients with low- and intermediate-risk EC.

  19. Dose verification in carcinoma of uterine cervix patients undergoing 3D conformal radiotherapy with Farmer type ion chamber

    Directory of Open Access Journals (Sweden)

    Challapalli Srinivas

    2014-01-01

    Full Text Available External beam radiotherapy (EBRT for carcinoma of uterine cervix is a basic line of treatment with three dimensional conformal radiotherapy (3DCRT in large number of patients. There is need for an established method for verification dosimetry. We tried to document absorbed doses in a group of carcinoma cervix patients by inserting a 0.6 cc Farmer type ion chamber in the vaginal cavity. A special long perspex sleeve cap is designed to cover the chamber for using in the patient′s body. Response of ionization chamber is checked earlier in water phantom with and without cap. Treatment planning was carried out with X-ray computed tomography (CT scan and with the chamber along with cap in inserted position, and with the images Xio treatment planning system. Three measurements on 3 days at 5-6 fraction intervals were recorded in 12 patients. Electrometer measured charges are converted to absorbed dose at the chamber center, in vivo. Our results show good agreement with planned dose within 3% against prescribed dose. This study, is a refinement over our previous studies with transmission dosimetry and chemicals in ampules. This preliminary work shows promise that this can be followed as a routine dose check with special relevance to new protocols in the treatment of carcinoma cervix with EBRT.

  20. Role of radiotherapy in the chemotherapy-containing multidisciplinary management of patients with resected pancreatic adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sole, Claudio V. [Instituto de Radiomedicina (IRAM), Department of Radiation Oncology, Santiago (Chile); Complutense University, School of Medicine, Madrid (Spain); Calvo, Felipe A. [Complutense University, School of Medicine, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Atahualpa, Freddy; Gonzalez-Bayon, Luis; Garcia-Sabrido, Jose Luis [Complutense University, School of Medicine, Madrid (Spain); Hospital General Universitario Gregorio Maranon, General Surgery Service III, Madrid (Spain); Berlin, Alejandro [Clinica Alemana de Santiago, Department of Radiation Oncology, Santiago (Chile); Herranz, Rafael [Hospital General Universitario Gregorio Maranon, Department of Radiation Oncology, Madrid (Spain)

    2014-10-08

    To analyze prognostic factors associated with long-term outcomes in patients with resected pancreatic cancer treated with chemotherapy (CT) and surgery with or without external beam radiotherapy (EBRT). From January 1995 to December 2012, 95 patients with adenocarcinoma of the pancreas and locoregional disease [clinical stage IB-IIA (n = 45; 47 %), IIB-IIIC (n = 50; 53 %)] were treated with curative resection [R0 (n = 52; 55 %), R1 (n = 43, 45 %)] and CT with (n = 60; 63 %) or without (n = 35; 37 %) EBRT (45-50.4 Gy). Additionally, 29 patients (48 %) also received a pre-anastomosis IOERT boost (applicator diameter size, 7-10 cm; dose, 10-15 Gy; beam energy, 9-18 MeV). With a median follow-up of 17.2 months (range, 1-182), 2-year overall survival (OS), disease-free survival (DFS), and locoregional control were 28, 20, and 53 %, respectively. Univariate analyses showed that IIB-IIIC stage (HR, 2.23; p = 0.04), R1 margin resection status (HR, 2.09; p = 0.04), no vascular resection (HR, 0.42; p = 0.02), and not receiving external beam radiotherapy (HR, 2.70; p = 0.004) were associated with locoregional recurrence. In the multivariate analysis, only R1 margin resection status (HR, 2.63; p = 0.009) and not receiving EBRT (HR, 2.91; p = 0.002) retained significance with regard to locoregional recurrence. We observed no difference in toxicity between patients treated with or without EBRT (p = 0.44). Overall treatment mortality was 3 %. No long-term treatment-related death occurred. Although adjuvant CT is still the standard of care for resected pancreatic tumors, OS remains modest owing to the high risk of distant metastases. Locoregional treatment needs to be tested in the context of more efficient systemic therapy. (orig.) [German] Zur Evaluierung von Prognosefaktoren im Rahmen von Langzeitresultaten bei Patienten mit reseziertem Pankreaskarzinom und verabreichter Chemotherapie (CT) mit oder ohne zusaetzlicher externer Radiotherapie (EBRT). Von Januar 1995 bis Dezember

  1. Evaluation of thermoluminescent BeO samples in standard radiotherapy beams; Avaliacao de amostras termoluminescentes de BeO em feixes padroes de radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, Daniela P.; Silva, Jonas O.; Caldas, Linda V.E., E-mail: daniela.piai.groppo@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-08-15

    Beryllium oxide thermoluminescent samples were evaluated in standard radiotherapy beams of low energy. Results for response reproducibility, dose-response curve and energy dependence were obtained. The lower detection limit was determined. The pellets of BeO showed their usefulness for beam dosimetry. (author)

  2. Volumetric Modulated Arc Radiotherapy for Early Stage Non-Small-Cell Lung Carcinoma: Is It Better Than the Conventional Static Beam Intensity Modulated Radiotherapy?

    Directory of Open Access Journals (Sweden)

    Vincent Wing Cheung Wu

    2014-01-01

    Full Text Available This study compared the performance of volumetric modulated arc therapy (VMAT techniques: single arc volumetric modulated arc therapy (SA-VMAT and double arc volumetric modulated arc therapy (DA-VMAT with the static beam conventional intensity modulated radiotherapy (C-IMRT for non-small-cell lung carcinoma (NSCLC. Twelve stage I and II NSCLC patients were recruited and their planning CT with contoured planning target volume (PTV and organs at risk (OARs was used for planning. Using the same dose constraints and planning objectives, the C-IMRT, SA-VMAT, and DA-VMAT plans were optimized. C-IMRT consisted of 7 static beams, while SA-VMAT and DA-VMAT plans consisted of one and two full gantry rotations, respectively. No significant difference was found among the three techniques in target homogeneity and conformity. Mean lung dose in C-IMRT plan was significantly lower than that in DA-VMAT plan P=0.04. The ability of OAR sparing was similar among the three techniques, with no significant difference in V20, V10, or V5 of normal lungs, spinal cord, and heart. Less MUs were required in SA-VMAT and DA-VMAT. Besides, SA-VMAT required the shortest beam on time among the three techniques. In treatment of early stage NSCLC, no significant dosimetric superiority was shown by the VMAT techniques over C-IMRT and DA-VMAT over SA-VMAT.

  3. Radiobiologically optimized couch shift: A new localization paradigm using cone-beam CT for prostate radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yimei, E-mail: yhuang2@hfhs.org; Gardner, Stephen J.; Wen, Ning; Zhao, Bo; Gordon, James; Brown, Stephen; Chetty, Indrin J. [Department of Radiation Oncology, Henry Ford Health System, 2799 W Grand Boulevard, Detroit, Michigan 48202 (United States)

    2015-10-15

    Purpose: To present a novel positioning strategy which optimizes radiation delivery by utilizing radiobiological response knowledge and evaluate its use during prostate external beam radiotherapy. Methods: Five patients with low or intermediate risk prostate cancer were evaluated retrospectively in this IRB-approved study. For each patient, a VMAT plan with one 358° arc was generated on the planning CT (PCT) to deliver 78 Gy in 39 fractions. Five representative pretreatment cone beam CTs (CBCT) were selected for each patient. The CBCT images were registered to PCT by a human observer, which consisted of an initial automated registration with three degrees-of-freedom, followed by manual adjustment for agreement at the prostate/rectal wall interface. To determine the optimal treatment position for each CBCT, a search was performed centering on the observer-matched position (OM-position) utilizing a score function based on radiobiological and dosimetric indices (EUD{sub prostate}, D99{sub prostate}, NTCP{sub rectum}, and NTCP{sub bladder}) for the prostate, rectum, and bladder. We termed the optimal treatment position the radiobiologically optimized couch shift position (ROCS-position). Results: The dosimetric indices, averaged over the five patients’ treatment plans, were (mean ± SD) 79.5 ± 0.3 Gy (EUD{sub prostate}), 78.2 ± 0.4 Gy (D99{sub prostate}), 11.1% ± 2.7% (NTCP{sub rectum}), and 46.9% ± 7.6% (NTCP{sub bladder}). The corresponding values from CBCT at the OM-positions were 79.5 ± 0.6 Gy (EUD{sub prostate}), 77.8 ± 0.7 Gy (D99{sub prostate}), 12.1% ± 5.6% (NTCP{sub rectum}), and 51.6% ± 15.2% (NTCP{sub bladder}), respectively. In comparison, from CBCT at the ROCS-positions, the dosimetric indices were 79.5 ± 0.6 Gy (EUD{sub prostate}), 77.3 ± 0.6 Gy (D99{sub prostate}), 8.0% ± 3.3% (NTCP{sub rectum}), and 46.9% ± 15.7% (NTCP{sub bladder}). Excessive NTCP{sub rectum} was observed on Patient 5 (19.5% ± 6.6%) corresponding to localization at OM

  4. On-line optimization of intraoperative electron beam radiotherapy of the breast

    International Nuclear Information System (INIS)

    Purpose: To optimize the dose delivery to the breast lumpectomy target treated with intraoperative electron beam radiotherapy (IOERT). Materials and methods: Two tools have been developed in our MU calculation software NEMO X to improve the dose homogeneity and the in-vivo dosimetry effectiveness for IOERT treatments. Given the target (tumor bed) thickness measured by the surgeon, NEMO X can provide auto dose normalization to cover 95% of the target volume with 95% of the prescription dose (PD) and a “best guess” of the expected dosimeter dose (EDD) for a deep seated in-vivo dosimeter. The tools have been validated with the data of 91 patients treated with IOERT on a LIAC mobile accelerator. In-vivo dosimetry has been performed with microMOSFETs positioned on the shielding disk inserted between the tumor bed and the chest wall. Results: On average the auto normalization showed to provide better results if compared to conventional normalization rules in terms of mean target dose (|MTD–PD|/PD ⩽ 5% in 95% vs. 53% of pts) and V107 percentage (〈V107〉 = 19% vs. 32%). In-vivo dosimetry MOSFET dose (MD) showed a better correlation with the EDD guessed by our tool than just by assuming that EDD = PD (|MD–EDD|/EDD ⩽ 5% in 57 vs. 26% of pts). Conclusions: NEMO X provides two useful tools for the on-line optimization of the dose delivery in IOERT. This optimization can help to reduce unnecessary large over-dosage regions and allows introducing reliable action levels for in-vivo dosimetry.

  5. Superficial dosimetry imaging of Čerenkov emission in electron beam radiotherapy of phantoms

    Science.gov (United States)

    Zhang, Rongxiao; Fox, Colleen J.; Glaser, Adam K.; Gladstone, David J.; Pogue, Brian W.

    2013-08-01

    Čerenkov emission is generated from ionizing radiation in tissue above 264 keV energy. This study presents the first examination of this optical emission as a surrogate for the absorbed superficial dose. Čerenkov emission was imaged from the surface of flat tissue phantoms irradiated with electrons, using a range of field sizes from 6 cm × 6 cm to 20 cm × 20 cm, incident angles from 0° to 50°, and energies from 6 to 18 MeV. The Čerenkov images were compared with the estimated superficial dose in phantoms from direct diode measurements, as well as calculations by Monte Carlo and the treatment planning system. Intensity images showed outstanding linear agreement (R2 = 0.97) with reference data of the known dose for energies from 6 to 18 MeV. When orthogonal delivery was carried out, the in-plane and cross-plane dose distribution comparisons indicated very little difference (±2-4% differences) between the different methods of estimation as compared to Čerenkov light imaging. For an incident angle 50°, the Čerenkov images and Monte Carlo simulation show excellent agreement with the diode data, but the treatment planning system had a larger error (OPT = ±1˜2%, diode = ±2˜3%, TPS = ±6-8% differences) as would be expected. The sampling depth of superficial dosimetry based on Čerenkov radiation has been simulated in a layered skin model, showing the potential of sampling depth tuning by spectral filtering. Taken together, these measurements and simulations indicate that Čerenkov emission imaging might provide a valuable method of superficial dosimetry imaging from incident radiotherapy beams of electrons.

  6. Dose calculation accuracy using cone-beam CT (CBCT) for pelvic adaptive radiotherapy

    Science.gov (United States)

    Guan, Huaiqun; Dong, Hang

    2009-10-01

    This study is to evaluate the dose calculation accuracy using Varian's cone-beam CT (CBCT) for pelvic adaptive radiotherapy. We first calibrated the Hounsfield Unit (HU) to electron density (ED) for CBCT using a mini CT QC phantom embedded into an IMRT QA phantom. We then used a Catphan 500 with an annulus around it to check the calibration. The combined CT QC and IMRT phantom provided correct HU calibration, but not Catphan with an annulus. For the latter, not only was the Teflon an incorrect substitute for bone, but the inserts were also too small to provide correct HUs for air and bone. For the former, three different scan ranges (6 cm, 12 cm and 20.8 cm) were used to investigate the HU dependence on the amount of scatter. To evaluate the dose calculation accuracy, CBCT and plan-CT for a pelvic phantom were acquired and registered. The single field plan, 3D conformal and IMRT plans were created on both CT sets. Without inhomogeneity correction, the two CT generated nearly the same plan. With inhomogeneity correction, the dosimetric difference between the two CT was mainly from the HU calibration difference. The dosimetric difference for 6 MV was found to be the largest for the single lateral field plan (maximum 6.7%), less for the 3D conformal plan (maximum 3.3%) and the least for the IMRT plan (maximum 2.5%). Differences for 18 MV were generally 1-2% less. For a single lateral field, calibration with 20.8 cm achieved the minimum dosimetric difference. For 3D and IMRT plans, calibration with a 12 cm range resulted in better accuracy. Because Catphan is the standard QA phantom for the on-board imager (OBI) device, we specifically recommend not using it for the HU calibration of CBCT.

  7. Optimum radiotherapy schedule for uterine cervical cancer based-on the detailed information of dose fractionation and radiotherapy technique

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jae Ho; Kim, Hyun Chang; Suh, Chang Ok [Yonsei University Medical School, Seoul (Korea, Republic of)] (and others)

    2005-09-15

    The best dose-fractionation regimen of the definitive radiotherapy for cervix cancer remains to be clearly determined. It seems to be partially attributed to the complexity of the affecting factors and the lack of detailed information on external and intra-cavitary fractionation. To find optimal practice guidelines, our experiences of the combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) were reviewed with detailed information of the various treatment parameters obtained from a large cohort of women treated homogeneously at a single institute. The subjects were 743 cervical cancer patients (Stage IB 198, IIA 77, IIB 364, IIIA 7, IIIB 89 and IVA 8) treated by radiotherapy alone, between 1990 and 1996. A total external beam radiotherapy (EBRT) dose of 23.4 {approx} 59.4 Gy (Median 45.0) was delivered to the whole pelvis. High-dose-rate intracavitary brachytherapy (HDR-ICBT) was also performed using various fractionation schemes. A Midline block (MLB) was initiated after the delivery of 14.4{approx} 43.2 Gy (Median 36.0) of EBRT in 495 patients, while in the other 248 patients EBRT could not be used due to slow tumor regression or the huge initial bulk of tumor. The point A, actual bladder and rectal doses were individually assessed in all patients. The biologically effective dose (BED) to the tumor ({alpha} / {beta} = 10) and late-responding tissues ({alpha} /{beta} = 3) for both EBRT and HDR-ICBT were calculated. The total BED values to point A, the actual bladder and rectal reference points were the summation of the EBRT and HDR-ICBT. In addition to all the details on dose-fractionation, the other factors (i.e. the overall treatment time, physicians preference) that can affect the schedule of the definitive radiotherapy were also thoroughly analyzed. The association between MD-BED Gy{sub 3} and the risk of complication was assessed using serial multiple logistic regressions models. The associations between R

  8. Organ doses can be estimated from the computed tomography (CT) dose index for cone-beam CT on radiotherapy equipment.

    Science.gov (United States)

    Martin, Colin J; Abuhaimed, Abdullah; Sankaralingam, Marimuthu; Metwaly, Mohamed; Gentle, David J

    2016-06-01

    Cone beam computed tomography (CBCT) systems are fitted to radiotherapy linear accelerators and used for patient positioning prior to treatment by image guided radiotherapy (IGRT). Radiotherapists' and radiographers' knowledge of doses to organs from CBCT imaging is limited. The weighted CT dose index for a reference beam of width 20 mm (CTDIw,ref) is displayed on Varian CBCT imaging equipment known as an On-Board Imager (OBI) linked to the Truebeam linear accelerator. This has the potential to provide an indication of organ doses. This knowledge would be helpful for guidance of radiotherapy clinicians preparing treatments. Monte Carlo simulations of imaging protocols for head, thorax and pelvic scans have been performed using EGSnrc/BEAMnrc, EGSnrc/DOSXYZnrc, and ICRP reference computational male and female phantoms to derive the mean absorbed doses to organs and tissues, which have been compared with values for the CTDIw,ref displayed on the CBCT scanner console. Substantial variations in dose were observed between male and female phantoms. Nevertheless, the CTDIw,ref gave doses within  ±21% for the stomach and liver in thorax scans and 2  ×  CTDIw,ref can be used as a measure of doses to breast, lung and oesophagus. The CTDIw,ref could provide indications of doses to the brain for head scans, and the colon for pelvic scans. It is proposed that knowledge of the link between CTDIw for CBCT should be promoted and included in the training of radiotherapy staff. PMID:26975735

  9. High-dose rate iridium-192 brachytherapy combined with external beam radiotherapy for localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kasahara, Kotaro; Inoue, Keiji; Karashima, Takashi; Inoue, Yuichiro; Kariya, Shinji; Inomata, Taisuke; Yoshida, Shoji; Shuin, Taro [Kochi Medical School, Nankoku (Japan)

    2001-07-01

    We report our technique and also preliminary results in the cases with localized prostate cancer treated by the combination of high-dose rate Iridium-192 (HDR-Ir 192) brachytherapy and external irradiation. From June 1999 to August 2000, 17 patients were treated by the combination of HDR-Ir 192 and external beam. The mean age of patients was 72 years (range, 48-81 years). The clinical stage was B1 in 5, B2 in 7 and C (no cancer with seminal vesicle) in 5 cases. Of 10 patients without neoadjuvant hormonal therapy, the median initial pretreatment PSA was 15.3 ng/ml (6.93-222.32 ng/ml). The treatment was given by HDR-Ir 192 brachytherapy (6 Gy x 3 times/2 days) and external beam irradiation (40 or 45 Gy). The brachytherapy was given using TRUS guided percutaneously inserted temporary needles with a high dose rate remote afterloading control. Local control was evaluated by digital rectal examination, TRUS-guided biopsies and serum PSA evaluations. Follow-up ranged from 2 to 14 months, with a median of 8 months. In 4 (40.0%) of 10 patients without neoadjuvant hormonal therapy the level of serum PSA was decreased to less than 4.0 ng/ml within 3 months after the therapy. The effective grade in the biopsy specimens of 8 patients without neoadjuvant hormonal therapy was Grade 0b in 4, Grade 1 in 1, Grade 3 in 3 cases at 3 months after the therapy. No severe intra-or peri-operative complications occurred. The combined radiotherapy treatment is safe and effective for use in the patients with localized prostate cancer. However, more comprehensive studies involving long-term follow-up and great numbers of the cases with localized prostate cancer treated by the combination of HDR-Ir 192 brachytherapy and external irradiation will be necessary to determine whether this therapy contributes to better prognosis. (author)

  10. Development of silicon monolithic arrays for dosimetry in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Bisello, Francesca, E-mail: francesca.bisello@iba-group.com [IBA Dosimetry GmbH, Schwarzenbruck (Germany); Friedrich-Alexander Universität Erlangen—Nürnberg, Erlangen (Germany); Menichelli, David [IBA Dosimetry GmbH, Schwarzenbruck (Germany); Scaringella, Monica [University of Florence, Firenze (Italy); INFN—Florence Division, Sesto Fiorentino (Italy); Talamonti, Cinzia; Zani, Margherita; Bucciolini, Marta [University of Florence, Firenze (Italy); Azienda Ospedaliera Unversitaria Careggi, Firenze (Italy); Bruzzi, Mara [University of Florence, Firenze (Italy); INFN—Florence Division, Sesto Fiorentino (Italy)

    2015-10-01

    New tools for dosimetry in external beam radiotherapy have been developed during last years in the framework of the collaboration among the University of Florence, INFN Florence and IBA Dosimetry. The first step (in 2007) was the introduction in dosimetry of detector solutions adopted from high energy physics, namely epitaxial silicon as the base detector material and a guard ring in diode design. This allowed obtaining state of the art radiation hardness, in terms of sensitivity dependence on accumulated dose, with sensor geometry particularly suitable for the production of monolithic arrays with modular design. Following this study, a 2D monolithic array has been developed, based on 6.3×6.3 cm{sup 2} modules with 3 mm pixel pitch. This prototype has been widely investigated and turned out to be a promising tool to measure dose distributions of small and IMRT fields. A further linear array prototype has been recently design with improve spatial resolution (1 mm pitch) and radiation hardness. This 24 cm long device is constituted by 4×64 mm long modules. It features low sensitivity changes with dose (0.2%/kGy) and dose per pulse (±1% in the range 0.1–2.3 mGy/pulse, covering applications with flattened and unflattened photon fields). The detector has been tested with very satisfactory results as a tool for quality assurance of linear accelerators, with special regards to small fields, and proton pencil beams. In this contribution, the characterization of the linear array with unflattened MV X-rays, {sup 60}Co radiation and 226 MeV protons is reported. - Highlights: • A silicon monolithic 1D array with 1 mm pixel pitch was developed. • The detector was characterized with {sup 60}Co, unflattened MV X-rays, 226 MeV protons. • Dose linearity in clinical relevance range and dose profiles were measured. • The detector performs good agreement with reference detectors. • The technology is suitable in dose profiling in MV X-ray and proton therapy.

  11. Effect of fractionated regional external beam radiotherapy on peripheral blood cell count

    International Nuclear Information System (INIS)

    Purpose: The purpose of this study was to assess the need for obtaining weekly complete blood count (CBC) values and to identify the pattern of changes in CBC during regional conventional fractionated radiotherapy. Methods and Materials: A retrospective analysis of CBC data on 299 adult cancer patients who received definitive conventional radiotherapy to head and neck (n=95), chest (n=96), and pelvis (n=108) was performed. Temporal patterns and magnitude of change in white blood cells, neutrophils, lymphocytes, and platelets during radiotherapy were examined. Results: There were statistically significant declines in all counts, albeit not clinically significant. Notable differences between disease sites were found. The greatest weekly interval change in counts occurred during the first week of radiotherapy for all groups of patients. The mean WBC nadir values during treatment were 5.8 for head and neck, 6.8 for chest, and 5.4 for pelvis. The nadirs for all counts occurred toward the middle-to-end of radiotherapy. Lymphocytes were found to be more sensitive to radiotherapy than other leukocyte subcomponents. Conclusion: Our study suggests that weekly CBC monitoring is not necessary for all patients undergoing standard fractionated radiotherapy. Baseline blood counts may be used to determine an optimal schedule for monitoring CBCs in patients receiving conventional radiation alone. Reduced monitoring of CBC may result in significant financial savings

  12. Environmental and social benefits of the targeted intraoperative radiotherapy for breast cancer: data from UK TARGIT-A trial centres and two UK NHS hospitals offering TARGIT IORT

    Science.gov (United States)

    Coombs, Nathan J; Coombs, Joel M; Vaidya, Uma J; Singer, Julian; Bulsara, Max; Tobias, Jeffrey S; Wenz, Frederik; Joseph, David J; Brown, Douglas A; Rainsbury, Richard; Davidson, Tim; Adamson, Douglas J A; Massarut, Samuele; Morgan, David; Potyka, Ingrid; Corica, Tammy; Falzon, Mary; Williams, Norman; Baum, Michael; Vaidya, Jayant S

    2016-01-01

    Objective To quantify the journeys and CO2 emissions if women with breast cancer are treated with risk-adapted single-dose targeted intraoperative radiotherapy (TARGIT) rather than several weeks' course of external beam whole breast radiotherapy (EBRT) treatment. Setting (1) TARGIT-A randomised clinical trial (ISRCTN34086741) which compared TARGIT with traditional EBRT and found similar breast cancer control, particularly when TARGIT was given simultaneously with lumpectomy, (2) 2 additional UK centres offering TARGIT. Participants 485 UK patients (249 TARGIT, 236 EBRT) in the prepathology stratum of TARGIT-A trial (where randomisation occurred before lumpectomy and TARGIT was delivered simultaneously with lumpectomy) for whom geographical data were available and 22 patients treated with TARGIT after completion of the TARGIT-A trial in 2 additional UK breast centres. Outcome measures The shortest total journey distance, time and CO2 emissions from home to hospital to receive all the fractions of radiotherapy. Methods Distances, time and CO2 emissions were calculated using Google Maps and assuming a fuel efficiency of 40 mpg. The groups were compared using the Student t test with unequal variance and the non-parametric Wilcoxon rank-sum (Mann-Whitney) test. Results TARGIT patients travelled significantly fewer miles: TARGIT 21 681, mean 87.1 (SE 19.1) versus EBRT 92 591, mean 392.3 (SE 30.2); had lower CO2 emissions 24.7 kg (SE 5.4) vs 111 kg (SE 8.6) and spent less time travelling: 3 h (SE 0.53) vs 14 h (SE 0.76), all p<0.0001. Patients treated with TARGIT in 2 hospitals in semirural locations were spared much longer journeys (753 miles, 30 h, 215 kg CO2 per patient). Conclusions The use of TARGIT intraoperative radiotherapy for eligible patients with breast cancer significantly reduces their journeys for treatment and has environmental benefits. If widely available, 5 million miles (8 000 000 km) of travel, 170 000 woman-hours and 1200

  13. Radiotherapy in the management of keloids. Clinical experience with electron beam irradiation and comparison with X-ray therapy

    Energy Technology Data Exchange (ETDEWEB)

    Maarouf, M. [Dept. of Radiotherapy, Univ. of Technology (RWTH), Aachen (Germany); Dept. of Stereotactic and Functional Neurosurgery, Univ. of Cologne (Germany); Schleicher, U.; Schmachtenberg, A.; Ammon, J. [Dept. of Radiotherapy, Univ. of Technology (RWTH), Aachen (Germany)

    2002-06-01

    Background: Aim of this study was to evaluate the advantages of electron beam irradiation compared to kilovoltage X-ray therapy in the treatment of keloids. Furthermore, the risk of developing malignancy following keloid radiotherapy was assessed. Patients and Methods: An automatic water phantom was used to evaluate the dose distribution in tissue. Furthermore, a series of measurements was done on the patients using thermoluminescence dosimeters (TLD) to estimate the doses absorbed by the organs at risk. We also report our clinical experience with electron beam radiation of 134 keloids following surgical excision. Results: Electron beam irradiation offers a high control rate (84%) with minimal side effects for keloids. Electron irradiation provides better dose distribution in tissue, and therefore less radiation burden to the organs at risk. After a mean follow-up period of 7.2 years, no severe side effects or malignancies were observed after keloid radiotherapy. Conclusions: Electron radiation therapy is superior to kilovoltage irradiation for treating keloids due to better dose distribution in tissue. In agreement with the literature, no cases of malignancy were observed after keloid irradiation. (orig.)

  14. Factors influencing the development of ulcers and strictures in carcinoma of the esophagus treated with radiotherapy with or without concurrent chemotherapy

    Directory of Open Access Journals (Sweden)

    Khurana Rohini

    2007-01-01

    Full Text Available Purpose: To ascertain factors that could influence the development of ulcers and strictures in the definitive management of squamous cell carcinoma (SCC of esophagus treated with external beam radiotherapy (EBRT, high-dose-rate (HDR intralumenal radiotherapy (ILRT with or without concurrent weekly cisplatin (CDDP @ 35 mg/m2 chemotherapy (CT. Materials and Methods: Between 1990-2005, 244 patients with inoperable SCC of esophagus were identified from our database and grouped into one of the following: those receiving at least 60Gy EBRT (Gp E, n=44; EBRT followed by HDR-ILRT (Gp E+I, n=98; at least 50Gy EBRT with CT (Gp E+C, n=68; EBRT+HDR-ILRT + CT (Gp E+I+C, n=34. Ulcers (discovered on endoscopy and strictures evident on a barium swallow (which needed dilatations were scored as treatment induced, if the biopsy was negative. Factors likely to influence their outcome were analyzed. Results: The groups were matched for all patient and disease characteristics except pretreatment hemoglobin and Karnofsky performance score (KPS, which were lower in Gp E. The incidence of ulcers was 7%, 8%, 6% and 21% ( P =0.08 while that of strictures was 14%, 9%, 21% and 41% ( P =0.00 for the groups E, E+I, E+C and E+I+C respectively. On univariate analysis, patients with better KPS ( P =0.03, treated with narrow applicators (6 mm vs. 10 mm, P =0.00, received CT ( P =0.00 or assigned to Gp E+I+C ( P =0.00 were more likely to develop strictures, with a trend for development of ulcers in Gp. E+I+C ( P =0.08. Logistic regression retained only Gp E+I+C for development of ulcers (OR 10.36, 95% CI 1.2-89.1, P =0.03 and strictures (OR 4.2, 95% CI 1.4-12.6, P =0.00. Conclusion: Treatment intensification as in Gp E+I+C results in about a three-fold increase in treatment induced late morbidity which can adversely impact on swallowing function and therefore emphasizes the need for optimisation of HDR-ILRT when used in a CT+RT protocol.

  15. Merkel cell carcinoma: Outcome and role of radiotherapy; Carcinome a cellules de Merkel: prise en charge et place de la radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Salvador Alonso, R.; Lahbabi, I.; Ben Hassel, M.; Boisselier, P.; Crevoisier, R. de [Centre Eugene-Marquis, Dept. de Radiotherapie, 35 - Rennes (France); Chaari, N. [Institut Gustave-Roussy, Dept. de Radiotherapie, 94 - Villejuif (France); Lesimple, T. [Centre Eugene-Marquis, Dept. d' Oncologie Medicale, 35 - Rennes (France); Chevrier, S. [Centre Hospitalier Prive de Saint-Gregoire, Dept. de Chirurgie Plastique, 35 - Saint-Gregoire (France)

    2008-09-15

    Merkel cell carcinoma (M.C.C.) are rare neuroendocrine malignant tumor of the skin, occurring in elderly patients. It affects primarily the sun-exposed areas of the skin, with approximately 50% of all tumors occurring in the face and neck and 40% in the extremities. Immunohistochemical markers (C.K.20+, C.K.7- and T.T.F.1-) are used to distinguish between M.C.C. and other tumors. M.C.C. have a tendency to rapid local progression, frequent spread to regional lymph nodes and distant metastases. Due to the rarity of the disease, the optimal treatment has not been fully defined. Localized stages (stages I and II) are treated by surgical excision of the primary tumor (with 2 to 3 cm margin) and lymphadenectomy in case of node-positive disease, followed by external beam radiotherapy (E.B.R.T.) to a total dose of 50 to 60 Gy in the tumor bed. Adjuvant E.B.R.T. has been shown to decrease markedly locoregional recurrences and to increase survival in recent studies. Treatment of lymph nodes area is more controversial. Chemotherapy is recommended only for metastatic disease. (authors)

  16. Intravitreal bevacizumab for macular edema due to proton beam radiotherapy: Favorable results shown after eighteen months follow-up

    Directory of Open Access Journals (Sweden)

    Eleni Loukianou

    2010-05-01

    Full Text Available Eleni Loukianou, Dimitrios Brouzas, Eleni Georgopoulou, Chrysanthi Koutsandrea, Michael ApostolopoulosEye Department, University of Athens, Athens, GreecePurpose: To evaluate the safety and efficacy of intravitreal injections of bevacizumab (Avastin® as a treatment option for radiation maculopathy secondary to proton beam radiotherapy for choroidal melanoma.Case: A 61-year-old woman presented with a gradual decrease in left eye visual acuity (VA 29 months after proton beam radiotherapy for choroidal melanoma. On presentation, her best-corrected VA (BCVA was 2/10 in the left eye and the intraocular pressure was 15 mmHg. Fundoscopy revealed cystoid macular edema, intraretinal hemorrhages, epiretinal membrane in the posterior pole, and residual tumor scar with exudative retinal detachment and hard exudates in the periphery of the superotemporal quadrant. A treatment with intravitreal injections of bevacizumab (Avastin® was recommended. The injections were performed on a six-weekly basis.Results: The central retinal thickness prior to the treatment was 458 μm. After the first intravitreal injection of bevacizumab, the retinal thickness at the centre of the fovea was reduced to 322 μm. After the third injection, the central retinal thickness was 359 μm and 18 months after presentation, it reduced to 334 μm. The BCVA increased to 3/10 after the intravitreal injections of bevacizumab and remained stable during the follow-up period. The intraocular pressure was within normal range during the follow-up period.Conclusion: Bevacizumab should be regarded as a treatment option for macular edema due to proton beam radiotherapy for choroidal melanoma. By reducing the central retinal thickness, intravitreal bevacizumab can improve VA or ameliorate further decline caused by radiation maculopathy.Keywords: bevacizumab (Avastin®, choroidal melanoma, macular edema, radiation retinopathy

  17. Radiotherapy for pituitary adenomas: long-term outcome and complications

    Energy Technology Data Exchange (ETDEWEB)

    Rim, Chai Hong; Yang, Dae Sik; Park, Young Je; Yoon, Won Sup; Lee, Jung AE; Kim, Chul Yong [Korea University Medical Center, Seoul (Korea, Republic of)

    2011-09-15

    To evaluate long-term local control rate and toxicity in patients treated with external beam radiotherapy (EBRT) for pituitary adenomas. We retrospectively reviewed the medical records of 60 patients treated with EBRT for pituitary adenoma at Korea University Medical Center from 1996 and 2006. Thirty-fi ve patients had hormone secreting tumors, 25 patients had non-secreting tumors. Fifty-seven patients had received postoperative radiotherapy (RT), and 3 had received RT alone. Median total dose was 54 Gy (range, 36 to 61.2 Gy). The definition of tumor progression were as follows: evidence of tumor progression on computed tomography or magnetic resonance imaging, worsening of clinical sign requiring additional operation or others, rising serum hormone level against a previously stable or falling value, and failure of controlling serum hormone level so that the hormone level had been far from optimal range until last follow-up. Age, sex, hormone secretion, tumor extension, tumor size, and radiation dose were analyzed for prognostic significance in tumor control. Median follow-up was 5.7 years (range, 2 to 14.4 years). The 10-year actuarial local control rates for non-secreting and secreting adenomas were 96% and 66%, respectively. In univariate analysis, hormone secretion was significant prognostic factor (p = 0.042) and cavernous sinus extension was marginally significant factor (p = 0.054) for adverse local control. All other factors were not significant. In multivariate analysis, hormone secretion and gender were significant. Fifty-three patients had mass-effect symptoms (headache, dizziness, visual disturbance, hypopituitarism, loss of consciousness, and cranial nerve palsy). A total of 17 of 23 patients with headache and 27 of 34 patients with visual impairment were improved. Twenty-seven patients experienced symptoms of endocrine hypersecretion (galactorrhea, amenorrhea, irregular menstruation, decreased libido, gynecomastia, acromegaly, and Cushing

  18. Radiotherapy for pituitary adenomas: long-term outcome and complications

    International Nuclear Information System (INIS)

    To evaluate long-term local control rate and toxicity in patients treated with external beam radiotherapy (EBRT) for pituitary adenomas. We retrospectively reviewed the medical records of 60 patients treated with EBRT for pituitary adenoma at Korea University Medical Center from 1996 and 2006. Thirty-fi ve patients had hormone secreting tumors, 25 patients had non-secreting tumors. Fifty-seven patients had received postoperative radiotherapy (RT), and 3 had received RT alone. Median total dose was 54 Gy (range, 36 to 61.2 Gy). The definition of tumor progression were as follows: evidence of tumor progression on computed tomography or magnetic resonance imaging, worsening of clinical sign requiring additional operation or others, rising serum hormone level against a previously stable or falling value, and failure of controlling serum hormone level so that the hormone level had been far from optimal range until last follow-up. Age, sex, hormone secretion, tumor extension, tumor size, and radiation dose were analyzed for prognostic significance in tumor control. Median follow-up was 5.7 years (range, 2 to 14.4 years). The 10-year actuarial local control rates for non-secreting and secreting adenomas were 96% and 66%, respectively. In univariate analysis, hormone secretion was significant prognostic factor (p = 0.042) and cavernous sinus extension was marginally significant factor (p = 0.054) for adverse local control. All other factors were not significant. In multivariate analysis, hormone secretion and gender were significant. Fifty-three patients had mass-effect symptoms (headache, dizziness, visual disturbance, hypopituitarism, loss of consciousness, and cranial nerve palsy). A total of 17 of 23 patients with headache and 27 of 34 patients with visual impairment were improved. Twenty-seven patients experienced symptoms of endocrine hypersecretion (galactorrhea, amenorrhea, irregular menstruation, decreased libido, gynecomastia, acromegaly, and Cushing's disease

  19. A GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    OpenAIRE

    Gu, Xuejun; Jelen, Urszula; Li, Jinsheng; Jia, Xun; Jiang, Steve B.

    2011-01-01

    Targeting at the development of an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite size pencil beam (FSPB) algorithm with a 3D-density correction method on GPU. This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework [Gu et al. Phys. Med. Biol. 54 6287-97, 2009]. Dosimetric evaluations against Monte Carlo dose calculations are conducted on 10 IMRT treatment plans (5 head-and-neck c...

  20. Characterization of a new ionization chamber in radiotherapy beams: angular dependence and variation of response with distance.

    Science.gov (United States)

    Silva, Jonas O; Linda V E, Caldas

    2012-10-01

    A new double faced ionization chamber was constructed at the Calibration Laboratory of IPEN. It has different collecting electrode materials: aluminum and graphite. It was irradiated in standard radiotherapy beams ((60)Co and X-rays). The response variation with distance and the angular dependence of this ionization chamber were evaluated. It was verified that the chamber response follows the inverse square law within a maximum variation of 11.2% in relation to the reference value. For the angular dependence it showed good agreement with international standards.

  1. The effectiveness of external beam radiotherapy for acromegaly is not affected by previous pituitary ablative treatments

    Energy Technology Data Exchange (ETDEWEB)

    Reed, P.I.; Joplin, G.F. (Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London (UK)); Speirs, C.J. (Department of Clinical Pharmacology, Royal Postgraduate Medical School, Hammersmith Hospital, London (UK)); Morrison, R. (Department of Radiotherapy, Royal Postgraduate Medical School, Hammersmith Hospital, London (UK)); Aber, V. (Department of Medical Physics, Royal Postgraduate Medical School, Hammersmith Hospital, London (UK))

    1990-01-01

    Thirty-three acromegalic patients were treated with radiotherapy and followed up for at least 3 years (mean 6 years, range 3 to 12). Seventeen had not had previous pituitary ablative therapy and 16 had. The mean GH level for these two groups before radiotherapy was comparable at 98 and 119 mlU/l. The observed frequency of reaching <10 mlU/L was 53% and 75% of patients in the two groups, respectively, the mean observed falls in growth hormone level were 81 and 85% of the initial level, and the calculated exponential decline rate of GH level was 72 and 52% per fyear. Considering all 35 patients, requirement for pituitary hormone replacement therapy increased from 15 patients before radiotherapy to 20 after radiotherapy, being mostly those who had had prior ablative therapies. There were no complications attributable to the radiotherapy treatment. It appears that radiotherapy is equally efficacious whether a prior unsuccessful ablative procedure had been used or not. (author).

  2. Radiation-induced second primary cancer risks from modern external beam radiotherapy for early prostate cancer: impact of stereotactic ablative radiotherapy (SABR), volumetric modulated arc therapy (VMAT) and flattening filter free (FFF) radiotherapy

    Science.gov (United States)

    Murray, Louise J.; Thompson, Christopher M.; Lilley, John; Cosgrove, Vivian; Franks, Kevin; Sebag-Montefiore, David; Henry, Ann M.

    2015-02-01

    Risks of radiation-induced second primary cancer following prostate radiotherapy using 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), flattening filter free (FFF) and stereotactic ablative radiotherapy (SABR) were evaluated. Prostate plans were created using 10 MV 3D-CRT (78 Gy in 39 fractions) and 6 MV 5-field IMRT (78 Gy in 39 fractions), VMAT (78 Gy in 39 fractions, with standard flattened and energy-matched FFF beams) and SABR (42.7 Gy in 7 fractions with standard flattened and energy-matched FFF beams). Dose-volume histograms from pelvic planning CT scans of three prostate patients, each planned using all 6 techniques, were used to calculate organ equivalent doses (OED) and excess absolute risks (EAR) of second rectal and bladder cancers, and pelvic bone and soft tissue sarcomas, using mechanistic, bell-shaped and plateau models. For organs distant to the treatment field, chamber measurements recorded in an anthropomorphic phantom were used to calculate OEDs and EARs using a linear model. Ratios of OED give relative radiation-induced second cancer risks. SABR resulted in lower second cancer risks at all sites relative to 3D-CRT. FFF resulted in lower second cancer risks in out-of-field tissues relative to equivalent flattened techniques, with increasing impact in organs at greater distances from the field. For example, FFF reduced second cancer risk by up to 20% in the stomach and up to 56% in the brain, relative to the equivalent flattened technique. Relative to 10 MV 3D-CRT, 6 MV IMRT or VMAT with flattening filter increased second cancer risks in several out-of-field organs, by up to 26% and 55%, respectively. For all techniques, EARs were consistently low. The observed large relative differences between techniques, in absolute terms, were very low, highlighting the importance of considering absolute risks alongside the corresponding relative risks, since when absolute

  3. External beam radiotherapy for basal cell carcinoma. Local control and cosmetic outcome; Strahlentherapie des Basalzellkarzinoms. Lokale Kontrolle und kosmetisches Ergebnis

    Energy Technology Data Exchange (ETDEWEB)

    Seegenschmiedt, M.H.; Oberste-Beulmann, S.; Guntrum, F.; Olschewski, T. [Krankenhaus Essen (Germany). Klinik fuer Radioonkologie, Strahlentherapie und Nuklearmedizin; Lang, E.; Lang, B. [Praxis fuer Dermatologie, Essen (Germany)

    2001-05-01

    Background: The basal cell carcinoma which is often occurring in the elderly can be well treated by surgery. For large and recurrent lesions and in cosmetically difficult locations external beam radiotherapy provides an equally effective treatment alternative. Patients and Methods: From 1986 to 1999, 60 females and 39 males received primary radiotherapy for a total of 127 histologically verified basal cell carcinoma lesions. Tumors were mostly localized in the face at the temple, nose and forehead. Radiotherapy was applied with orthovoltage equipment and energies of up to 100 kV. Single doses ranged from 2 to 5 Gy related to the 80%-isodose depth. Weekly doses ranged from 8 to 25 Gy and total doses from 25 to 60 Gy. The mean follow-up period was 36{+-}21 months. The acute sequelae were scored according to CTC criteria. Radiogenic late effects as single events were related to the radiation portal. Results: 3 months after treatment all besides one patient (99%) experienced complete tumor remission (CR). In all cases, acute radiation reaction occurred within the radiation portal: CTC Grade 1 in 100%, CTC Grade 2 in 54% and CTC Grade 3 in 30% of the cases. All side effects regressed under simple local measures without further complications. Late sequelae were observed in three cases. Overall cosmetic outcome was good to excellent in almost all patients (98%). In two cases (2%) a local recurrence was observed 6 and 20 months after radiotherapy. Conclusion: External beam (orthovoltage) radiotherapy is very effective and yields high tumor control rates and good cosmetic results in long-term follow-up. Former dermatological treatment concepts should be replaced by an ICRU-based radiophysical dose prescription and should respect the newer radiobiological fractionation principles. (orig.) [German] Hintergrund: Das Basaliom oder Basalzellkarzinom ist ein im Alter haeufig vorkommender Hauttumor, der chirurgisch gut behandelbar ist. Bei grossen und rezidivierenden Tumoren und

  4. SU-D-213-02: Characterization of the Effect of a New Commercial Transmission Detector On Radiotherapy Beams

    International Nuclear Information System (INIS)

    Purpose: To evaluate the influence of a new commercial transmission detector on radiotherapy beams of various energies. Methods: A transmission detector designed for online treatment monitoring was characterized on a TrueBeam STx linear accelerator with 6MV, 6FFF, 10MV, and 10FFF beams. Measurements of beam characteristics including percentage depth doses (PDDs), inplane and crossplane off-axis profiles at different depths, transmission factors, and skin dose were acquired at field sizes of 3×3cm, 5×5m, 10×10cm, and 20×20cm at 100cm and 80cm source-to-surface distance (SSD). All measurements were taken with and without the transmission detector in the path of the beam. A CC04 chamber was used for all profile and transmission factor measurements. Skin dose was assessed at 100cm, 90cm, and 80cm SSD and using a variety of detectors (Roos and Markus parallel-plate chambers, and OSLD). Results: The PDDs showed small differences between the unperturbed and perturbed beams for both 100cm and 80cm SSD (≤4mm dmax difference and <1.2% average profile difference). The differences were larger for the flattened beams and at larger field sizes. The off-axis profiles showed similar trends. The penumbras looked similar with and without the transmission detector. Comparisons in the central 80% of the profile showed a maximum average (maximum) profile difference between all field sizes of 0.756% (1.535%) and 0.739% (3.682%) for 100cm and 80cm SSD, respectively. The average measured skin dose at 100cm (80cm) SSD for 10×10cm field size was <4% (<35%) dose increase for all energies. For 20×20cm field size, this value increased to <10% (≤45%). Conclusion: The transmission detector has minimal effect on the clinically relevant radiotherapy beams for IMRT and VMAT (field sizes 10×10cm and less). For larger field sizes, some perturbations are observable which would need to be assessed for clinical impact. The authors of this publication has research support from IBA Dosimetry

  5. SU-D-213-02: Characterization of the Effect of a New Commercial Transmission Detector On Radiotherapy Beams

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, J; Morin, O [University of California San Francisco, San Francisco, CA (United States)

    2015-06-15

    Purpose: To evaluate the influence of a new commercial transmission detector on radiotherapy beams of various energies. Methods: A transmission detector designed for online treatment monitoring was characterized on a TrueBeam STx linear accelerator with 6MV, 6FFF, 10MV, and 10FFF beams. Measurements of beam characteristics including percentage depth doses (PDDs), inplane and crossplane off-axis profiles at different depths, transmission factors, and skin dose were acquired at field sizes of 3×3cm, 5×5m, 10×10cm, and 20×20cm at 100cm and 80cm source-to-surface distance (SSD). All measurements were taken with and without the transmission detector in the path of the beam. A CC04 chamber was used for all profile and transmission factor measurements. Skin dose was assessed at 100cm, 90cm, and 80cm SSD and using a variety of detectors (Roos and Markus parallel-plate chambers, and OSLD). Results: The PDDs showed small differences between the unperturbed and perturbed beams for both 100cm and 80cm SSD (≤4mm dmax difference and <1.2% average profile difference). The differences were larger for the flattened beams and at larger field sizes. The off-axis profiles showed similar trends. The penumbras looked similar with and without the transmission detector. Comparisons in the central 80% of the profile showed a maximum average (maximum) profile difference between all field sizes of 0.756% (1.535%) and 0.739% (3.682%) for 100cm and 80cm SSD, respectively. The average measured skin dose at 100cm (80cm) SSD for 10×10cm field size was <4% (<35%) dose increase for all energies. For 20×20cm field size, this value increased to <10% (≤45%). Conclusion: The transmission detector has minimal effect on the clinically relevant radiotherapy beams for IMRT and VMAT (field sizes 10×10cm and less). For larger field sizes, some perturbations are observable which would need to be assessed for clinical impact. The authors of this publication has research support from IBA Dosimetry.

  6. Treatment planning for radiotherapy with very high-energy electron beams and comparison of VHEE and VMAT plans

    Energy Technology Data Exchange (ETDEWEB)

    Bazalova-Carter, Magdalena; Qu, Bradley; Palma, Bianey; Jensen, Christopher; Maxim, Peter G., E-mail: Peter.Maxim@Stanford.edu, E-mail: BWLoo@Stanford.edu; Loo, Billy W., E-mail: Peter.Maxim@Stanford.edu, E-mail: BWLoo@Stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Hårdemark, Björn; Hynning, Elin [RaySearch Laboratories AB, Stockholm SE-103 65 (Sweden)

    2015-05-15

    Purpose: The aim of this work was to develop a treatment planning workflow for rapid radiotherapy delivered with very high-energy electron (VHEE) scanning pencil beams of 60–120 MeV and to study VHEE plans as a function of VHEE treatment parameters. Additionally, VHEE plans were compared to clinical state-of-the-art volumetric modulated arc therapy (VMAT) photon plans for three cases. Methods: VHEE radiotherapy treatment planning was performed by linking EGSnrc Monte Carlo (MC) dose calculations with inverse treatment planning in a research version of RayStation. In order to study the effect of VHEE treatment parameters on VHEE dose distributions, a MATLAB graphical user interface (GUI) for calculation of VHEE MC pencil beam doses was developed. Through the GUI, pediatric case MC simulations were run for a number of beam energies (60, 80, 100, and 120 MeV), number of beams (13, 17, and 36), pencil beam spot (0.1, 1.0, and 3.0 mm) and grid (2.0, 2.5, and 3.5 mm) sizes, and source-to-axis distance, SAD (40 and 50 cm). VHEE plans for the pediatric case calculated with the different treatment parameters were optimized and compared. Furthermore, 100 MeV VHEE plans for the pediatric case, a lung, and a prostate case were calculated and compared to the clinically delivered VMAT plans. All plans were normalized such that the 100% isodose line covered 95% of the target volume. Results: VHEE beam energy had the largest effect on the quality of dose distributions of the pediatric case. For the same target dose, the mean doses to organs at risk (OARs) decreased by 5%–16% when planned with 100 MeV compared to 60 MeV, but there was no further improvement in the 120 MeV plan. VHEE plans calculated with 36 beams outperformed plans calculated with 13 and 17 beams, but to a more modest degree (<8%). While pencil beam spacing and SAD had a small effect on VHEE dose distributions, 0.1–3 mm pencil beam sizes resulted in identical dose distributions. For the 100 MeV VHEE pediatric

  7. Persistent pain after targeted intraoperative radiotherapy (TARGIT) or external breast radiotherapy for breast cancer: A randomized trial

    DEFF Research Database (Denmark)

    Andersen, Kenneth Geving; Gärtner, Rune; Kroman, Niels;

    2012-01-01

    Persistent pain after breast cancer treatment (PPBCT) affects between 25 and 60% of patients depending on surgical and adjuvant treatment. External breast radiotherapy (EBRT) has been shown to be a riskfactor for PPBCT, raising the question whether intraoperative radiation therapy (IORT), with its...

  8. Multicenter study differentiated thyroid carcinoma (MSDS). Diminished acceptance of adjuvant external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, M.; Pixberg, M.K.; Schober, O. [Muenster Univ. (Germany). Dept. of Nuclear Medicine; Schuck, A.; Willich, N. [Muenster Univ. (Germany). Dept. of Radiooncology; Heinecke, A.; Koepke, W. [Muenster Univ. (Germany). Dept. of Medical Informatics and Biomathematics; Schmid, K.W. [Essen Univ. (Germany). Dept. of Pathology; Dralle, H. [Halle-Wittenberg Univ., Halle (Germany). Dept. of Surgery

    2003-12-01

    Aim: The Multicenter Study Differentiated Thyroid Carcinoma (MSDS) is an ongoing study in Germany, Austria, and Switzerland on the clinical benefit of adjuvant external beam radiotherapy (RTx) for locally invasive differentiated thyroid carcinoma (DTC) in TNM stages pT4 pNO/1/xMO/x (5th ed. 1997). Methods: MSDS was designed as a prospective randomized trial. Patients receive thyroidectomy, radioiodine therapy (RIT) to ablate the thyroid remnant, and TSH-suppressive L-thyroxine therapy with or without RTx after documented elimination of cervical iodine-131 uptake (http://msds-studie.uni-muenster.de). Results: 311 patients were enrolled between January 2000 and March 2003. 279 patients met the trial's inclusion criteria. 45 consented to randomization, of whom 17 were randomized into treatment arm A (RTx) and 18 into arm B (no RTx). Advised by the trial's independent Data Monitoring and Safety Committee, the MSDS steering committee decided to terminate randomization in April 2003 and continue MSDS as a prospective cohort study. 23 of the 234 patients in the observation arm of the trial were prescribed RTx by their physicians. Thus, 14% of the trial cohort were randomized or assigned to receive RTx (intention-to-treat analysis). In contrast, at least 44% of all patients with pT4 papillary DTC in Germany in the nationwide PCES study underwent RTx in 1996 (p<0.001, {chi}{sup 2}-test). Conclusions: Acceptance of external beam RTx as a treatment modality for DTC has receded to a degree that accrual of a sufficient number of patients for a randomized trial has been impossible. Observation of the trial cohort is continued in order to assess clinical event rates with and without RTx and chronic RTx toxicity. (orig.) [German] Ziel: Die Multizentrische Studie Differenziertes Schilddruesenkarzinom (MSDS) ist eine laufende Studie in Deutschland, Oesterreich und der Schweiz zum klinischen Nutzen der adjuvanten perkutanen Strahlentherapie (RTx) bei lokal invasivem

  9. Polymer gels impregnated with gold nanoparticles implemented for measurements of radiation dose enhancement in synchrotron and conventional radiotherapy type beams

    International Nuclear Information System (INIS)

    Normoxic type polyacrylamide gel (nPAG) dosimeters are established for dose quantification in three-dimensions for radiotherapy and hence represent an adequate dosimeter for quantification of the dose variation due to the existence of the gold nanoparticles (AuNPs) in the target during irradiation. This work compared the degree of polymerisation in gel doped with nanoparticles (nPAG–AuNP) with control gel samples when irradiated by various sources. Samples were irradiated with a synchrotron radiation source of mean energy 125 keV, 80 kV X-ray beams from superficial therapy machine (SXRT), 6 MV X-rays and 6 MeV electron beams from linear accelerator. Analysis of the dose–response relation was used to determine a dose enhancement factor (DEF) of 1.76 ± 0.34 and 1.64 ± 0.44 obtained for samples irradiated with kilovoltage X-rays energy from synchrotron source and SXRT respectively. Similarly, including AuNPs in gel results in a DEF of approximately 1.37 ± 0.35 when irradiated by an electron beam and 1.14 ± 0.28 for high energy X-ray beams. The results demonstrate the use of AuNPs embedded in polymer gels for measuring the enhancement of radiation caused by metallic nanoparticles.

  10. Prognostic Value of External Beam Radiation Therapy in Patients Treated With Surgical Resection and Intraoperative Electron Beam Radiation Therapy for Locally Recurrent Soft Tissue Sarcoma: A Multicentric Long-Term Outcome Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Felipe A. [Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); School of Medicine, Complutense University, Madrid (Spain); Sole, Claudio V., E-mail: cvsole@uc.cl [Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); School of Medicine, Complutense University, Madrid (Spain); Service of Radiation Oncology, Instituto de Radiomedicina, Santiago (Chile); Cambeiro, Mauricio [Service of Radiation Oncology, Clínica Universitaria, Universidad de Navarra, Pamplona (Spain); Montero, Angel; Polo, Alfredo [Service of Radiation Oncology, Hospital Universitario Ramón y Cajal, Universidad de Alcala, Madrid (Spain); Gonzalez, Carmen [School of Medicine, Complutense University, Madrid (Spain); Service of Radiation Oncology, Instituto de Radiomedicina, Santiago (Chile); Service of Radiation Oncology, Clínica Universitaria, Universidad de Navarra, Pamplona (Spain); Service of Radiation Oncology, Hospital Universitario Ramón y Cajal, Universidad de Alcala, Madrid (Spain); Service of Radiation Oncology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); Cuervo, Miguel [Service of Orthopedics and Traumatology, Hospital General Universitario Gregorio Marañón, Madrid (Spain); San Julian, Mikel [Service of Orthopedics and Traumatology, Clínica Universitaria, Universidad de Navarra, Pamplona (Spain); and others

    2014-01-01

    Background: A joint analysis of data from centers involved in the Spanish Cooperative Initiative for Intraoperative Electron Radiotherapy was performed to investigate long-term outcomes of locally recurrent soft tissue sarcoma (LR-STS) patients treated with a multidisciplinary approach. Methods and Materials: Patients with a histologic diagnosis of LR-STS (extremity, 43%; trunk wall, 24%; retroperitoneum, 33%) and no distant metastases who underwent radical surgery and intraoperative electron radiation therapy (IOERT; median dose, 12.5 Gy) were considered eligible for participation in this study. In addition, 62% received external beam radiation therapy (EBRT; median dose, 50 Gy). Results: From 1986 to 2012, a total of 103 patients from 3 Spanish expert IOERT institutions were analyzed. With a median follow-up of 57 months (range, 2-311 months), 5-year local control (LC) was 60%. The 5-year IORT in-field control, disease-free survival (DFS), and overall survival were 73%, 43%, and 52%, respectively. In the multivariate analysis, no EBRT to treat the LR-STS (P=.02) and microscopically involved margin resection status (P=.04) retained significance in relation to LC. With regard to IORT in-field control, only not delivering EBRT to the LR-STS retained significance in the multivariate analysis (P=.03). Conclusion: This joint analysis revealed that surgical margin and EBRT affect LC but that, given the high risk of distant metastases, DFS remains modest. Intensified local treatment needs to be further tested in the context of more efficient concurrent, neoadjuvant, and adjuvant systemic therapy.

  11. Potential for enhancing external beam radiotherapy for lung cancer using high-Z nanoparticles administered via inhalation

    Science.gov (United States)

    Hao, Yao; Altundal, Yucel; Moreau, Michele; Sajo, Erno; Kumar, Rajiv; Ngwa, Wilfred

    2015-09-01

    Nanoparticle-aided radiation therapy is emerging as a promising modality to enhance radiotherapy via the radiosensitizing action of high atomic number (Z) nanoparticles. However, the delivery of sufficiently potent concentrations of such nanoparticles to the tumor remain a challenge. This study investigates the dose enhancement to lung tumors due to high-Z nanoparticles (NPs) administered via inhalation during external beam radiotherapy. Here NPs investigated include: cisplatin nanoparticles (CNPs), carboplatin nanoparticles (CBNPs), and gold nanoparticles (GNPs). Using Monte Carlo-generated megavoltage energy spectra, a previously employed analytic method was used to estimate dose enhancement to lung tumors due to radiation-induced photoelectrons from the NPs administered via inhalation route (IR) in comparison to intravenous (IV) administration. Previous studies have indicated about 5% of FDA-approved cisplatin concentrations reach the lung via IV. Meanwhile recent experimental studies indicate that 3.5-14.6 times higher concentrations of NPs can reach the lung by IR compared to IV. Taking these into account, the dose enhancement factor (DEF) defined as the ratio of the radiotherapy dose with and without nanoparticles was calculated for a range of NPs concentrations and tumor sizes. The DEF for IR was then compared with that for IV. For IR with 3.5 times higher concentrations than IV, and 2 cm diameter tumor, clinically significant DEF values of up to 1.19, 1.26, and 1.51 were obtained for CNPs, CBNPs and GNPs. In comparison values of 1.06, 1.08, and 1.15 were obtained via IV administration. For IR with 14.6 times higher concentrations, even higher DEF values were obtained e.g. 1.81 for CNPs. Results also showed that the DEF increased with increasing field size or decreasing tumor volume, as expected. The results of this work indicate that IR administration of targeted high-Z CNPs/CBNPs/GNPs could enable clinically significant DEF to lung tumors compared to IV

  12. Potential for enhancing external beam radiotherapy for lung cancer using high-Z nanoparticles administered via inhalation.

    Science.gov (United States)

    Hao, Yao; Altundal, Yucel; Moreau, Michele; Sajo, Erno; Kumar, Rajiv; Ngwa, Wilfred

    2015-09-21

    Nanoparticle-aided radiation therapy is emerging as a promising modality to enhance radiotherapy via the radiosensitizing action of high atomic number (Z) nanoparticles. However, the delivery of sufficiently potent concentrations of such nanoparticles to the tumor remain a challenge. This study investigates the dose enhancement to lung tumors due to high-Z nanoparticles (NPs) administered via inhalation during external beam radiotherapy. Here NPs investigated include: cisplatin nanoparticles (CNPs), carboplatin nanoparticles (CBNPs), and gold nanoparticles (GNPs). Using Monte Carlo-generated megavoltage energy spectra, a previously employed analytic method was used to estimate dose enhancement to lung tumors due to radiation-induced photoelectrons from the NPs administered via inhalation route (IR) in comparison to intravenous (IV) administration. Previous studies have indicated about 5% of FDA-approved cisplatin concentrations reach the lung via IV. Meanwhile recent experimental studies indicate that 3.5-14.6 times higher concentrations of NPs can reach the lung by IR compared to IV. Taking these into account, the dose enhancement factor (DEF) defined as the ratio of the radiotherapy dose with and without nanoparticles was calculated for a range of NPs concentrations and tumor sizes. The DEF for IR was then compared with that for IV. For IR with 3.5 times higher concentrations than IV, and 2 cm diameter tumor, clinically significant DEF values of up to 1.19, 1.26, and 1.51 were obtained for CNPs, CBNPs and GNPs. In comparison values of 1.06, 1.08, and 1.15 were obtained via IV administration. For IR with 14.6 times higher concentrations, even higher DEF values were obtained e.g. 1.81 for CNPs. Results also showed that the DEF increased with increasing field size or decreasing tumor volume, as expected. The results of this work indicate that IR administration of targeted high-Z CNPs/CBNPs/GNPs could enable clinically significant DEF to lung tumors compared to IV

  13. Potential for enhancing external beam radiotherapy for lung cancer using high-Z nanoparticles administered via inhalation

    International Nuclear Information System (INIS)

    Nanoparticle-aided radiation therapy is emerging as a promising modality to enhance radiotherapy via the radiosensitizing action of high atomic number (Z) nanoparticles. However, the delivery of sufficiently potent concentrations of such nanoparticles to the tumor remain a challenge. This study investigates the dose enhancement to lung tumors due to high-Z nanoparticles (NPs) administered via inhalation during external beam radiotherapy. Here NPs investigated include: cisplatin nanoparticles (CNPs), carboplatin nanoparticles (CBNPs), and gold nanoparticles (GNPs).Using Monte Carlo–generated megavoltage energy spectra, a previously employed analytic method was used to estimate dose enhancement to lung tumors due to radiation-induced photoelectrons from the NPs administered via inhalation route (IR) in comparison to intravenous (IV) administration. Previous studies have indicated about 5% of FDA-approved cisplatin concentrations reach the lung via IV. Meanwhile recent experimental studies indicate that 3.5–14.6 times higher concentrations of NPs can reach the lung by IR compared to IV. Taking these into account, the dose enhancement factor (DEF) defined as the ratio of the radiotherapy dose with and without nanoparticles was calculated for a range of NPs concentrations and tumor sizes. The DEF for IR was then compared with that for IV.For IR with 3.5 times higher concentrations than IV, and 2 cm diameter tumor, clinically significant DEF values of up to 1.19, 1.26, and 1.51 were obtained for CNPs, CBNPs and GNPs. In comparison values of 1.06, 1.08, and 1.15 were obtained via IV administration. For IR with 14.6 times higher concentrations, even higher DEF values were obtained e.g. 1.81 for CNPs. Results also showed that the DEF increased with increasing field size or decreasing tumor volume, as expected.The results of this work indicate that IR administration of targeted high-Z CNPs/CBNPs/GNPs could enable clinically significant DEF to lung tumors compared to IV

  14. A novel four-dimensional radiotherapy planning strategy from a tumor-tracking beam's eye view

    Science.gov (United States)

    Li, Guang; Cohen, Patrice; Xie, Huchen; Low, Daniel; Li, Diana; Rimner, Andreas

    2012-11-01

    To investigate the feasibility of four-dimensional radiotherapy (4DRT) planning from a tumor-tracking beam's eye view (ttBEV) with reliable gross tumor volume (GTV) delineation, realistic normal tissue representation, high planning accuracy and low clinical workload, we propose and validate a novel 4D conformal planning strategy based on a synthesized 3.5D computed tomographic (3.5DCT) image with a motion-compensated tumor. To recreate patient anatomy from a ttBEV in the moving tumor coordinate system for 4DRT planning (or 4D planning), the centers of delineated GTVs in all phase CT images of 4DCT were aligned, and then the aligned CTs were averaged to produce a new 3.5DCT image. This GTV-motion-compensated CT contains a motionless target (with motion artifacts minimized) and motion-blurred normal tissues (with a realistic temporal density average). Semi-automatic threshold-based segmentation of the tumor, lung and body was applied, while manual delineation was used for other organs at risk (OARs). To validate this 3.5DCT-based 4D planning strategy, five patients with peripheral lung lesions of small size (V50) of prescribed dose of these 4D plans. The volume of the delineated GTV from different phase CTs varied dramatically from 24% to 112% among the five patients, whereas the GTV from 3.5DCT deviated from the averaged GTV in 4DCT by only -6%±6%. For planning tumor volume (PTV) coverage, the difference between the DVH3.5D and iDVH4D was negligible (<1% area), whereas the DVH3.5D and DVH4D were quite different, due to DIR uncertainty (˜2 mm), which propagates to PTV dose coverage with a pronounced uncertainty for small tumors (0.3-4.0 cm3) in stereotactic plans with sharp dose falloff around PTV. For OARs, such as the lung, heart, cord and esophagus, the three DVH curves (DVH3.5D, DVH4D and iDVH4D) were found to be almost identical for the same patients, especially in high-dose regions. For the tumor-containing lung, the relative difference of the areas

  15. Minimal requirements for quality controls in radiotherapy with external beams; Controlli di qualita' essenziali in radioterapia con fasci esterni

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    Physical dosimetric guidelines have been developed by the Italian National Institute of Health study group on quality assurance in radiotherapy to define protocols for quality controls in external beam radiotherapy. While the document does not determine strict rules or firm recommendations, it suggests minimal requirements for quality controls necessary to guarantee an adequate degree of accuracy in external beam radiotherapy. [Italian] Il gruppo di studio Assicurazione di qualita' in radioterapia dell'Istituto Superiore di Sanita' presenta le linee guida per la stesura dei protocolli di controllo di qualita' essenziali necessari a garantire un adeguato livello di accuratezza del trattamento radiante e rappresenta pertanto una parte essenziale del contributo fisico-dosimetrico globale di assicurazione di qualita' in radioterapia con fasci esterni.

  16. The feasibility and safety of high-intensity focused ultrasound combined with low-dose external beam radiotherapy as supplemental therapy for advanced prostate cancer following hormonal therapy

    OpenAIRE

    Wu, Rui-Yi; Wang, Guo-Min; Xu, Lei; ZHANG, BO-HENG; Xu, Ye-Qing; Zeng, Zhao-Chong; Chen, Bing

    2011-01-01

    The aim of this study was to investigate the feasibility and safety of high-intensity focused ultrasound (HIFU) combined with (+) low-dose external beam radiotherapy (LRT) as supplemental therapy for advanced prostate cancer (PCa) following hormonal therapy (HT). Our definition of HIFU+LRT refers to treating primary tumour lesions with HIFU in place of reduced field boost irradiation to the prostate, while retaining four-field box irradiation to the pelvis in conventional-dose external beam r...

  17. Prediction of lung density changes after radiotherapy by cone beam computed tomography response markers and pre-treatment factors for non-small cell lung cancer patients

    DEFF Research Database (Denmark)

    Bernchou, Uffe; Hansen, Olfred; Schytte, Tine;

    2015-01-01

    BACKGROUND AND PURPOSE: This study investigates the ability of pre-treatment factors and response markers extracted from standard cone-beam computed tomography (CBCT) images to predict the lung density changes induced by radiotherapy for non-small cell lung cancer (NSCLC) patients. METHODS...

  18. Comparative evaluation of a novel 3D segmentation algorithm on in-treatment radiotherapy cone beam CT images

    Science.gov (United States)

    Price, Gareth; Moore, Chris

    2007-03-01

    Image segmentation and delineation is at the heart of modern radiotherapy, where the aim is to deliver as high a radiation dose as possible to a cancerous target whilst sparing the surrounding healthy tissues. This, of course, requires that a radiation oncologist dictates both where the tumour and any nearby critical organs are located. As well as in treatment planning, delineation is of vital importance in image guided radiotherapy (IGRT): organ motion studies demand that features across image databases are accurately segmented, whilst if on-line adaptive IGRT is to become a reality, speedy and correct target identification is a necessity. Recently, much work has been put into the development of automatic and semi-automatic segmentation tools, often using prior knowledge to constrain some grey level, or derivative thereof, interrogation algorithm. It is hoped that such techniques can be applied to organ at risk and tumour segmentation in radiotherapy. In this work, however, we make the assumption that grey levels do not necessarily determine a tumour's extent, especially in CT where the attenuation coefficient can often vary little between cancerous and normal tissue. In this context we present an algorithm that generates a discontinuity free delineation surface driven by user placed, evidence based support points. In regions of sparse user supplied information, prior knowledge, in the form of a statistical shape model, provides guidance. A small case study is used to illustrate the method. Multiple observers (between 3 and 7) used both the presented tool and a commercial manual contouring package to delineate the bladder on a serially imaged (10 cone beam CT volumes ) prostate patient. A previously presented shape analysis technique is used to quantitatively compare the observer variability.

  19. Assessment of contrast enhanced respiration managed cone-beam CT for image guided radiotherapy of intrahepatic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Nikolaj K. G., E-mail: nkyj@regionsjaelland.dk [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Stewart, Errol [Radiology, St. Joseph' s Health Care, London, Ontario N6A 4V2 (Canada); Imaging Research Lab, Robarts Research Institute, London, Ontario N6A 5B7 (Canada); Imaging Program, Lawson Health Research Institute, London, Ontario N6C 2R5 (Canada); Lock, Michael; Fisher, Barbara [Radiation Oncology, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Kozak, Roman [Radiology, St. Joseph' s Health Care, London, Ontario N6A 4V2 (Canada); Chen, Jeff [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Lee, Ting-Yim [Radiology, St. Joseph' s Health Care, London, Ontario N6A 4V2 (Canada); Imaging Research Lab, Robarts Research Institute, London, Ontario N6A 5B7 (Canada); Imaging Program, Lawson Health Research Institute, London, Ontario N6C 2R5 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Wong, Eugene [Physics and Engineering, London Regional Cancer Program, London, Ontario N6A3K7 (Canada); Department of Oncology, University of Western Ontario, London, Ontario N6A 4L6 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 5C1 (Canada); Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

    2014-05-15

    Purpose: Contrast enhancement and respiration management are widely used during image acquisition for radiotherapy treatment planning of liver tumors along with respiration management at the treatment unit. However, neither respiration management nor intravenous contrast is commonly used during cone-beam CT (CBCT) image acquisition for alignment prior to radiotherapy. In this study, the authors investigate the potential gains of injecting an iodinated contrast agent in combination with respiration management during CBCT acquisition for liver tumor radiotherapy. Methods: Five rabbits with implanted liver tumors were subjected to CBCT with and without motion management and contrast injection. The acquired CBCT images were registered to the planning CT to determine alignment accuracy and dosimetric impact. The authors developed a simulation tool for simulating contrast-enhanced CBCT images from dynamic contrast enhanced CT imaging (DCE-CT) to determine optimal contrast injection protocols. The tool was validated against contrast-enhanced CBCT of the rabbit subjects and was used for five human patients diagnosed with hepatocellular carcinoma. Results: In the rabbit experiment, when neither motion management nor contrast was used, tumor centroid misalignment between planning image and CBCT was 9.2 mm. This was reduced to 2.8 mm when both techniques were employed. Tumors were not visualized in clinical CBCT images of human subjects. Simulated contrast-enhanced CBCT was found to improve tumor contrast in all subjects. Different patients were found to require different contrast injections to maximize tumor contrast. Conclusions: Based on the authors’ animal study, respiration managed contrast enhanced CBCT improves IGRT significantly. Contrast enhanced CBCT benefits from patient specific tracer kinetics determined from DCE-CT.

  20. Assessment of contrast enhanced respiration managed cone-beam CT for image guided radiotherapy of intrahepatic tumors

    International Nuclear Information System (INIS)

    Purpose: Contrast enhancement and respiration management are widely used during image acquisition for radiotherapy treatment planning of liver tumors along with respiration management at the treatment unit. However, neither respiration management nor intravenous contrast is commonly used during cone-beam CT (CBCT) image acquisition for alignment prior to radiotherapy. In this study, the authors investigate the potential gains of injecting an iodinated contrast agent in combination with respiration management during CBCT acquisition for liver tumor radiotherapy. Methods: Five rabbits with implanted liver tumors were subjected to CBCT with and without motion management and contrast injection. The acquired CBCT images were registered to the planning CT to determine alignment accuracy and dosimetric impact. The authors developed a simulation tool for simulating contrast-enhanced CBCT images from dynamic contrast enhanced CT imaging (DCE-CT) to determine optimal contrast injection protocols. The tool was validated against contrast-enhanced CBCT of the rabbit subjects and was used for five human patients diagnosed with hepatocellular carcinoma. Results: In the rabbit experiment, when neither motion management nor contrast was used, tumor centroid misalignment between planning image and CBCT was 9.2 mm. This was reduced to 2.8 mm when both techniques were employed. Tumors were not visualized in clinical CBCT images of human subjects. Simulated contrast-enhanced CBCT was found to improve tumor contrast in all subjects. Different patients were found to require different contrast injections to maximize tumor contrast. Conclusions: Based on the authors’ animal study, respiration managed contrast enhanced CBCT improves IGRT significantly. Contrast enhanced CBCT benefits from patient specific tracer kinetics determined from DCE-CT

  1. Consensus and differences in primary radiotherapy for localized and locally advanced prostate cancer in Switzerland. A survey on patterns of practice

    Energy Technology Data Exchange (ETDEWEB)

    Panje, Cedric M. [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland); Universitaetsspital Zuerich, Department of Radiation Oncology, Zurich (Switzerland); Dal Pra, Alan [Inselspital Bern, Department of Radiation Oncology, Bern (Switzerland); Zilli, Thomas [Hopitaux Universitaires de Geneve, Department of Radiation Oncology, Geneva (Switzerland); Zwahlen, Daniel R. [Kantonsspital Graubuenden, Department of Radiation Oncology, Chur (Switzerland); Papachristofilou, Alexandros [Universitaetsspital Basel, Department of Radiation Oncology, Basel (Switzerland); Herrera, Fernanda G. [Centre Hospitalier Universitaire Vaudois, Department of Radiation Oncology, Lausanne (Switzerland); Matzinger, Oscar [Hopital Riviera-Chablais, Department of Radiation Oncology, Vevey (Switzerland); Plasswilm, Ludwig; Putora, Paul Martin [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland)

    2015-10-15

    External beam radiotherapy (EBRT), with or without androgen deprivation therapy (ADT), is an established treatment option for nonmetastatic prostate cancer. Despite high-level evidence from several randomized trials, risk group stratification and treatment recommendations vary due to contradictory or inconclusive data, particularly with regard to EBRT dose prescription and ADT duration. Our aim was to investigate current patterns of practice in primary EBRT for prostate cancer in Switzerland. Treatment recommendations on EBRT and ADT for localized and locally advanced prostate cancer were collected from 23 Swiss radiation oncology centers. Written recommendations were converted into center-specific decision trees, and analyzed for consensus and differences using a dedicated software tool. Additionally, specific radiotherapy planning and delivery techniques from the participating centers were assessed. The most commonly prescribed radiation dose was 78 Gy (range 70-80 Gy) across all risk groups. ADT was recommended for intermediate-risk patients for 6 months in over 80 % of the centers, and for high-risk patients for 2 or 3 years in over 90 % of centers. For recommendations on combined EBRT and ADT treatment, consensus levels did not exceed 39 % in any clinical scenario. Arc-based intensity-modulated radiotherapy (IMRT) is implemented for routine prostate cancer radiotherapy by 96 % of the centers. Among Swiss radiation oncology centers, considerable ranges of radiotherapy dose and ADT duration are routinely offered for localized and locally advanced prostate cancer. In the vast majority of cases, doses and durations are within the range of those described in current evidence-based guidelines. (orig.) [German] Die Radiotherapie (RT) ist als Monotherapie oder in Kombination mit einer Androgendeprivationstherapie (ADT) eine etablierte Behandlungsoption fuer das lokalisierte und lokal fortgeschrittene Prostatakarzinom. Trotz der guten Evidenzlage durch zahlreiche

  2. Radiobiological Characterization of Two Photon-Beam Energies 6 and 15 MV used in Radiotherapy From Linear Accelerator

    International Nuclear Information System (INIS)

    The main objective of this study is to perform radiobiological characterization of two different photon beam energies, 6 MV and 15 MV, from linear accelerator used in radiotherapy, with special regard to late effects of radiation. Two end-points, namely cell survival and micronucleus induction were used for the characterization. Chinese hamster V 79 lung fibroblast cell line to prepare cell culture and to perform the innervate experiments. chromosomes number was counted and found to be 22 chromosomes per cell, this result is in complete agreement with expected 11 pairs of chromosomes representing the genome of this species. Cells were kept in confluent growth for two days and then exposed to two photon beam energies, 6 and 15 MV respectively. Different dose rates were used for the two beam energies, 0.25, 0.5, 1.0, 2.0, 4.0, 7.0 Gy. Cells were counted immediately after irradiation and re seeded, the seeded number of cells was calculated to the dose rate used. Another set of unirradiated cells treated the same as the experimental set was used as a control group. The plating efficiency (PE) was calculated for the control group, then cells were incubated at 37oC for 6 days to construct the survival curve, five samples were counted per dose and the mean was calculated. The two survival curves are similar for photon beam energies (6 and 15 MV) and the surviving fraction was decreased with dose rate. The two curves showed similar values of α and β parameters, this result is expected for the same radiation type (X-ray). For the micronuclei assay three samples for each dose were seeded and incubated at 37oC for 24 hours then Cytochalasin-B was added to block cells in cytokinesis phase of the mitosis. The micronuclei number was counted and plotted with dose. A significant positive correlation was found between dose and micronuclei frequency (P=0.00), moreover, the micronuclei frequency is relatively higher with 15 MV compared with 6 MV energy. This indicates the presence

  3. A technique to re-establish dose distributions for previously treated brain cancer patients in external beam radiotherapy

    International Nuclear Information System (INIS)

    Tumor recurrences or new tumors may develop after irradiation of local lesion(s) in the brain, and additional radiotherapy treatments are often needed for previously treated patients. It is critical to re-establish the dose distributions delivered during the previous treatment in the current patient geometry, so that the previous dose distributions can be accurately taken into consideration in the design of the current treatment plan. The difficulty in re-establishing the previous treatment dose distributions in the current patient geometry arises from the fact that the patient position at the time of reirradiation is different from that at the previous treatment session. Simple re-entry of the previous isocenter coordinates, gantry, and couch and collimator angles into the new treatment plan would result in incorrect beam orientations relative to the new patient anatomy, and therefore incorrect display of the previous dose distributions on the current patient anatomy. To address this issue, a method has been developed so that the previous dose distributions can be accurately re-established in the framework of the current brain treatment. The method involves 3 matrix transformations: (1) transformation of beams from machine coordinate system to patient coordinate system in the previous treatment; (2) transformation of beams from patient coordinate system in the previous treatment to patient coordinate system in the current treatment; and (3) transformation of beams from patient coordinate system in the current treatment to machine coordinate system. The transformation matrices used in the second transformation are determined by registration using a mutual information-based algorithm with which the old and new computed tomography (CT) scan sets are registered automatically without human interpretation. A series of transformation matrices are derived to calculate the isocenter coordinates, the gantry, couch, and collimator angles of the beams for the previous

  4. The optimal utilization proportion of external beam radiotherapy in European countries: An ESTRO-HERO analysis

    International Nuclear Information System (INIS)

    Background and purpose: The absolute number of new cancer patients that will require at least one course of radiotherapy in each country of Europe was estimated. Material and methods: The incidence and relative frequency of cancer types from the year 2012 European Cancer Observatory estimates were used in combination with the population-based stage at diagnosis from five cancer registries. These data were applied to the decision trees of the evidence-based indications to calculate the Optimal Utilization Proportion (OUP) by tumour site. Results: In the minimum scenario, the OUP ranged from 47.0% in the Russian Federation to 53.2% in Belgium with no clear geographical pattern of the variability among countries. The impact of stage at diagnosis on the OUP by country was rather limited. Within the 24 countries where data on actual use of radiotherapy were available, a gap between optimal and actual use has been observed in most of the countries. Conclusions: The actual utilization of radiotherapy is significantly lower than the optimal use predicted from the evidence based estimates in the literature. This discrepancy poses a major challenge for policy makers when planning the resources at the national level to improve the provision in European countries

  5. Radiotherapy of Teikyo University. (1) Experience and the current status at Itabashi Hospital. External beam therapy

    International Nuclear Information System (INIS)

    Since 1971, Itabashi hospital of Teikyo University began using the practice of radiotherapy. Since then, data has been compiled in notebook form. This was a slow and inconvenient way to log data. We tried to change the out-of-date form to a more convenient and available one. We input the radiotherapy (RT) number, ID, name, sex, primary disease, the refered department and the initial date of the radiotherapy of all cases into a PC. A total of 5072 new patients were summed up by the end of 2001. The number of the new patients has been increasing annually, and there were 235 cases in 2001. The largest group in these patients was head and neck tumors, which consisted 1180 patients (23.3%). The second largest group was gynecologic tumors, 766 cases (15.1%), and the third one was respiratory tumors, 648 cases (12.8%). The number of the respiratory tumors, the digestive tumors and the urological tumors have been increasing markedly, which became more than twice the number in 30 years. Especially, the ratio of the respiratory group and the digestive group have increased every year. The ratio of gynecologic tumors decreased markedly (25.1%→9.3%). To answer the current demand of the information disclosure, we should continue to open the up-to-date status and the therapeutic results of our practice. (author)

  6. Standard operating procedures for quality audits of 60Co external beam radiotherapy facilities

    International Nuclear Information System (INIS)

    The use of radiotherapy implies the necessity of rigorous quality standards in its different components, aimed to provide the best possible treatment and avoid potential patients' risks, that could even cause him death. Projects of technical cooperation developed in Cuba and supported by the International Atomic Energy Agency address the implementation of Programs of Quality Assurance (PGC) in radiotherapy services. The establishment of the National Quality Audit Program (PNAC) is a superior stage. The National Control Center for Medical Devices, as the national regulator entity for the control and supervision of medical devices in the National Health System, is responsible for the making and execution of the PNAC. The audit modality selected was the inspection visit in situ due to its intrinsic advantages, our geographical extension and the number of radiotherapy services. This paper presents the methodology for the execution of the PNAC, in form of a Normalized Procedure of Operation (PNO) that defines the objectives, scope, terms and definitions, responsibilities, composition and selection of the auditor team, security's conditions, materials and equipment, steps of the audit execution, results calculation and interpretation, records, etc. (author)

  7. Real-time optical-fibre luminescence dosimetry for radiotherapy: physical characteristics and applications in photon beams

    Energy Technology Data Exchange (ETDEWEB)

    Aznar, Marianne C [Radiation Research Department, Risoe National Laboratory, Roskilde (Denmark); Andersen, Claus E [Radiation Research Department, Risoe National Laboratory, Roskilde (Denmark); Boetter-Jensen, Lars [Radiation Research Department, Risoe National Laboratory, Roskilde (Denmark); Baeck, Sven A J [Department of Medical Radiation Physics, Lund University, Malmoe University Hospital, Malmoe (Sweden); Mattsson, Soeren [Department of Medical Radiation Physics, Lund University, Malmoe University Hospital, Malmoe (Sweden); Kjaer-Kristoffersen, Flemming [Department of Radiation Physics, Rigshospitalet, National University Hospital, Copenhagen (Denmark); Medin, Joakim [Department of Medical Radiation Physics, Lund University, Malmoe University Hospital, Malmoe (Sweden)

    2004-05-07

    A new optical-fibre radiation dosimeter system, based on radioluminescence and optically stimulated luminescence from carbon-doped aluminium oxide, was developed and tested in clinical photon beams. This prototype offers several features, such as a small detector (1 x 1 x 2 mm{sup 3}), high sensitivity, real-time read-out and the ability to measure both dose rate and absorbed dose. The measurements describing reproducibility and output dependence on dose rate, field size and energy all had standard deviations smaller than 1%. The signal variation with the angle of incidence was smaller than 2% (1 SD). Measurements performed in clinical situations suggest the potential of using this real-time system for in vivo dosimetry in radiotherapy.

  8. The choice of multi-beam IMRT for whole breast radiotherapy in early-stage right breast cancer.

    Science.gov (United States)

    Haciislamoglu, Emel; Colak, Fatma; Canyilmaz, Emine; Zengin, Ahmet Yasar; Yilmaz, Ahmet Hakan; Yoney, Adnan; Bahat, Zumrut

    2016-01-01

    The aim of this study was to identify a rational strategy for the selection of multi-beam IMRT in patients with right breast cancer through the comparison of dosimetric parameters of the planning target volume (PTV) and organs at risk (OARs) using five different radiotherapy modalities. This was a retrospective study using computed tomography scans from ten patients with early-stage right breast cancer who had been treated previously. Three dimensional conformal radiotherapy (3DCRT), forward-planned IMRT (for-IMRT), inverse-planned IMRT (inv-IMRT), helical tomotherapy (HT), and volumetric-modulated arc therapy (VMAT) were planned for each patient. The plans were compared according to dose-volume histogram analysis. The most significant impact of inverse-planned multi-beam modalities for right breast cancer was the reduction of Dmax, Dmean, V53.5 and prescribed dose volume (cc) outside of the PTV (breast) (OB-V50) of the PTV. HT decreased the ipsilateral OAR volumes receiving higher doses. In exchange, HT also increased the volumes receiving low doses, which is known to lead to an increased rate of radiation-induced secondary malignancies. The heart, LAD, and contralateral doses for 3DCRT and for-IMRT were significantly lower than those for inv-IMRT, HT, and VMAT. In addition, inv-IMRT demonstrated an increase in exposed volume of heart, LAD, ipsilateral lung, and contralateral lung compared with those parameters for HT or VMAT. Although it is known to reduce cardiac toxicity with breath hold technique in left sided breast cancer, similarly it is possible for 3DCRT and for-IMRT techniques in right sided breast cancer even in free breathing. PMID:27350922

  9. Patterns of radiotherapy practice for biliary tract cancer in Japan: results of the Japanese radiation oncology study group (JROSG) survey

    International Nuclear Information System (INIS)

    The patterns of radiotherapy (RT) practice for biliary tract cancer (BTC) in Japan are not clearly established. A questionnaire-based national survey of RT used for BTC treatment between 2000 and 2011 was conducted by the Japanese Radiation Oncology Study Group. Detailed information was collected for 555 patients from 31 radiation oncology institutions. The median age of the patients was 69 years old (range, 33–90) and 81% had a good performance status (0–1). Regarding RT treatment, 78% of the patients were treated with external beam RT (EBRT) alone, 17% received intraluminal brachytherapy, and 5% were treated with intraoperative RT. There was no significant difference in the choice of treatment modality among the BTC subsites. Many patients with EBRT were treated with a total dose of 50 or 50.4 Gy (~40%) and only 13% received a total dose ≥60 Gy, even though most institutions (90%) were using CT-based treatment planning. The treatment field consisted of the primary tumor (bed) only in 75% of the patients. Chemotherapy was used for 260 patients (47%) and was most often administered during RT (64%, 167/260), followed by after RT (63%, 163/260). Gemcitabine was the most frequently used drug for chemotherapy. This study established the general patterns of RT practice for BTC in Japan. Further surveys and comparisons with results from other countries are needed for development and optimization of RT for patients with BTC in Japan

  10. A particle swarm optimization algorithm for beam angle selection in intensity-modulated radiotherapy planning

    International Nuclear Information System (INIS)

    Automatic beam angle selection is an important but challenging problem for intensity-modulated radiation therapy (IMRT) planning. Though many efforts have been made, it is still not very satisfactory in clinical IMRT practice because of overextensive computation of the inverse problem. In this paper, a new technique named BASPSO (Beam Angle Selection with a Particle Swarm Optimization algorithm) is presented to improve the efficiency of the beam angle optimization problem. Originally developed as a tool for simulating social behaviour, the particle swarm optimization (PSO) algorithm is a relatively new population-based evolutionary optimization technique first introduced by Kennedy and Eberhart in 1995. In the proposed BASPSO, the beam angles are optimized using PSO by treating each beam configuration as a particle (individual), and the beam intensity maps for each beam configuration are optimized using the conjugate gradient (CG) algorithm. These two optimization processes are implemented iteratively. The performance of each individual is evaluated by a fitness value calculated with a physical objective function. A population of these individuals is evolved by cooperation and competition among the individuals themselves through generations. The optimization results of a simulated case with known optimal beam angles and two clinical cases (a prostate case and a head-and-neck case) show that PSO is valid and efficient and can speed up the beam angle optimization process. Furthermore, the performance comparisons based on the preliminary results indicate that, as a whole, the PSO-based algorithm seems to outperform, or at least compete with, the GA-based algorithm in computation time and robustness. In conclusion, the reported work suggested that the introduced PSO algorithm could act as a new promising solution to the beam angle optimization problem and potentially other optimization problems in IMRT, though further studies need to be investigated

  11. The Relationship Between Local Recurrence and Radiotherapy Treatment Volume for Soft Tissue Sarcomas Treated With External Beam Radiotherapy and Function Preservation Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Dickie, Colleen I., E-mail: Colleen.dickie@rmp.uhn.on.ca [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); Griffin, Anthony M. [Division of Orthopaedic Surgery, University Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto (Canada); University of Toronto, Toronto (Canada); Parent, Amy L. [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); Chung, Peter W.M.; Catton, Charles N. [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); University of Toronto, Toronto (Canada); Svensson, Jon [AngliaRuskin University, Cambridge (United Kingdom); Ferguson, Peter C.; Wunder, Jay S.; Bell, Robert S. [Division of Orthopaedic Surgery, University Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto (Canada); University of Toronto, Toronto (Canada); Sharpe, Michael B.; O' Sullivan, Brian [Radiation Medicine Program, Princess Margaret Hospital, Toronto (Canada); University of Toronto, Toronto (Canada)

    2012-03-15

    Purpose: To examine the geometric relationship between local recurrence (LR) and external beam radiotherapy (RT) volumes for soft-tissue sarcoma (STS) patients treated with function-preserving surgery and RT. Methods and Materials: Sixty of 768 (7.8%) STS patients treated with combined therapy within our institution from 1990 through 2006 developed an LR. Thirty-two received preoperative RT, 16 postoperative RT, and 12 preoperative RT plus a postoperative boost. Treatment records, RT simulation images, and diagnostic MRI/CT data sets of the original and LR disease were retrospectively compared. For LR location analysis, three RT target volumes were defined according to the International Commission on Radiation Units and Measurements 29 as follows: (1) the gross tumor or operative bed; (2) the treatment volume (TV) extending 5 cm longitudinally beyond the tumor or operative bed unless protected by intact barriers to spread and at least 1-2 cm axially (the TV was enclosed by the isodose curve representing the prescribed target absorbed dose [TAD] and accounted for target/patient setup uncertainty and beam characteristics), and (3) the irradiated volume (IRV) that received at least 50% of the TAD, including the TV. LRs were categorized as developing in field within the TV, marginal (on the edge of the IRV), and out of field (occurring outside of the IRV). Results: Forty-nine tumors relapsed in field (6.4% overall). Nine were out of field (1.1% overall), and 2 were marginal (0.3% overall). Conclusions: The majority of STS tumors recur in field, indicating that the incidence of LR may be affected more by differences in biologic and molecular characteristics rather than aberrations in RT dose or target volume coverage. In contrast, only two patients relapsed at the IRV boundary, suggesting that the risk of a marginal relapse is low when the TV is appropriately defined. These data support the accurate delivery of optimal RT volumes in the most precise way using advanced

  12. Characterization of standard and oxygenated float zone Si diodes under radiotherapy beams

    International Nuclear Information System (INIS)

    The dosimetric response of silicon diodes made from high resistivity float zone (FZ) and diffusion oxygenated FZ (DOFZ) silicon has been studied with a 60Co clinical radiotherapy gamma source. To investigate the changes in sensitivity with the accumulated dose, the diodes have been exposed to doses of 137Cs gamma-rays up to 6 kGy. As expected, Si diodes showed a degradation in the signal response with the accumulated dose due to the formation of radiation-induced defects acting as lifetime killers. Nonetheless, the DOFZ Si diode appeared to be moderately radiation harder than the standard FZ sample, with a decay of sensitivity less pronounced

  13. Characterization of standard and oxygenated float zone Si diodes under radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Casati, M. [INFN Firenze and Dipartimento di Fisiopatologia Clinica, University of Florence (Italy)]. E-mail: marta.casati@unifi.it; Bruzzi, M. [INFN Firenze and Dipartimento di Energetica, University of Florence (Italy); Bucciolini, M. [INFN Firenze and Dipartimento di Fisiopatologia Clinica, University of Florence (Italy); Menichelli, D. [INFN Firenze and Dipartimento di Fisiopatologia Clinica, University of Florence (Italy); Scaringella, M. [INFN Firenze and Dipartimento di Energetica, University of Florence (Italy); Piemonte, C. [ITC-IRST, MIS Division, Povo, Trento (Italy); Fretwurst, E. [Institute for Experimental Physics, University of Hamburg D-22761 (Germany)

    2005-10-21

    The dosimetric response of silicon diodes made from high resistivity float zone (FZ) and diffusion oxygenated FZ (DOFZ) silicon has been studied with a {sup 60}Co clinical radiotherapy gamma source. To investigate the changes in sensitivity with the accumulated dose, the diodes have been exposed to doses of {sup 137}Cs gamma-rays up to 6 kGy. As expected, Si diodes showed a degradation in the signal response with the accumulated dose due to the formation of radiation-induced defects acting as lifetime killers. Nonetheless, the DOFZ Si diode appeared to be moderately radiation harder than the standard FZ sample, with a decay of sensitivity less pronounced.

  14. Advances of Precise Radiotherapy for Lung Cancer

    Directory of Open Access Journals (Sweden)

    Xin WANG

    2011-11-01

    Full Text Available At present lung tumor radiation therapy has entered the accurate radiotherapy era. Precise radiotherapy includes intensity modulated radiotherapy (IMRT, image-guided radiotherapy (IGRT and stereotactic body radiotherapy (SBRT. During the process of implementing precise radiotherapy, these problems should be fully considered to ensure executing precise radiotherapy accurately: patient positioning, controlling of the lung tumor motion, selecting of image techniques, PTV margin, dose prescription and reporting, arrangement of beams, controlling of dose volume and treatment delivering.

  15. Advanced Electron Beam Ion Sources (EBIS) for 2-nd generation carbon radiotherapy facilities

    International Nuclear Information System (INIS)

    In this work we analyze how advanced Electron Beam Ion Sources (EBIS) can facilitate the progress of carbon therapy facilities. We will demonstrate that advanced ion sources enable operation of 2-nd generation ion beam therapy (IBT) accelerators. These new accelerator concepts with designs dedicated to IBT provide beams better suited for therapy and, are more cost efficient than contemporary IBT facilities. We will give a sort overview of the existing new IBT concepts and focus on those where ion source technology is the limiting factor. We will analyse whether this limitation can be overcome in the near future thanks to ongoing EBIS development

  16. Local Control Rates of Metastatic Renal Cell Carcinoma (RCC) to Thoracic, Abdominal, and Soft Tissue Lesions Using Stereotactic Body Radiotherapy (SBRT)

    OpenAIRE

    Altoos, Basel; Amini, Arya; Yacoub, Muthanna; Bourlon, Maria T.; Kessler, Elizabeth E.; Flaig, Thomas W.; Fisher, Christine M.; Kavanagh, Brian D.; Lam, Elaine T.; Karam, Sana D.

    2015-01-01

    Background and purpose We report the radiographic response rate of SBRT compared to conventional fractionated radiotherapy (CF-EBRT) for thoracic, abdominal, skin and soft tissue RCC lesions treated at our institution. Material and methods Fifty three lesions where included in the study (36 SBRT, 17 CF-EBRT), treated from 2004 to 2014 at our institution. We included patients that had thoracic, skin & soft tissue (SST), and abdominal metastases of histologically confirmed RCC. The most common ...

  17. External Beam Radiotherapy of Recurrent Glioma: Radiation Tolerance of the Human Brain

    Energy Technology Data Exchange (ETDEWEB)

    Sminia, Peter, E-mail: p.sminia@vumc.nl [Department of Radiation Oncology, Radiobiology Section, VU University Medical Center, De Boelelaan 1117, P.O. Box 7057, Amsterdam (Netherlands); Mayer, Ramona [EBG MedAustron GmbH., Viktor Kaplan-Strasse 2, A-2700, Wiener Neustadt (Austria)

    2012-04-05

    Malignant gliomas relapse in close proximity to the resection site, which is the postoperatively irradiated volume. Studies on re-irradiation of glioma were examined regarding radiation-induced late adverse effects (i.e., brain tissue necrosis), to obtain information on the tolerance dose and treatment volume of normal human brain tissue. The studies were analyzed using the linear-quadratic model to express the re-irradiation tolerance in cumulative equivalent total doses when applied in 2 Gy fractions (EQD2{sub cumulative}). Analysis shows that the EQD2{sub cumulative} increases from conventional re-irradiation series to fractionated stereotactic radiotherapy (FSRT) to LINAC-based stereotactic radiosurgery (SRS). The mean time interval between primary radiotherapy and the re-irradiation course was shortened from 30 months for conventional re-irradiation to 17 and 10 months for FSRT and SRS, respectively. Following conventional re-irradiation, radiation-induced normal brain tissue necrosis occurred beyond an EQD2{sub cumulative} around 100 Gy. With increasing conformality of therapy, the smaller the treatment volume is, the higher the radiation dose that can be tolerated. Despite the dose escalation, no increase in late normal tissue toxicity was reported. On basis of our analysis, the use of particle therapy in the treatment of recurrent gliomas, because of the optimized physical dose distribution in the tumour and surrounding healthy brain tissue, should be considered for future clinical trials.

  18. A GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    CERN Document Server

    Gu, Xuejun; Li, Jinsheng; Jia, Xun; Jiang, Steve B

    2011-01-01

    Targeting at developing an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite size pencil beam (FSPB) algorithm with a 3D-density correction method on GPU. This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework [Gu et al. Phys. Med. Biol. 54 6287-97, 2009]. Dosimetric evaluations against MCSIM Monte Carlo dose calculations are conducted on 10 IMRT treatment plans with heterogeneous treatment regions (5 head-and-neck cases and 5 lung cases). For head and neck cases, when cavities exist near the target, the improvement with the 3D-density correction over the conventional FSPB algorithm is significant. However, when there are high-density dental filling materials in beam paths, the improvement is small and the accuracy of the new algorithm is still unsatisfactory. On the other hand, significant improvement of dose calculation accuracy is observed in all lung cases. Especially when the target is in the m...

  19. SU-E-T-415: An Ionization Chamber Array with High Spatial Resolution for External Beam Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Togno, M [Klinikum rechts der Isar, Technische Universitaet Muenchen, Muenchen (Germany); IBA Dosimetry, Schwarzenbruck (Germany); Wilkens, J [Klinikum rechts der Isar, Technische Universitaet Muenchen, Muenchen (Germany); Menichelli, D [IBA Dosimetry, Schwarzenbruck (Germany)

    2014-06-01

    Purpose: To characterize an ionization chamber array technology with high spatial resolution and high charge collection efficiency for external beam radiotherapy. Methods: The prototype under test is a linear array of air vented ionization chambers developed by IBA Dosimetry, consisting of 80 pixels with 3.5mm spatial resolution and 4mm{sup 3} sensitive volume. The detector was characterized in a plastic phantom with {sup 60} Co radiation and MV X-rays from an ELEKTA Agility LINAC (with flattened and unflattened beam qualities). Bias voltage was varied in order to evaluate charge collection efficiency. A commercial array of ionization chambers (MatriXX Evolution, IBA Dosimetry) and an amorphous silicon flat panel in direct conversion configuration were used as references. Results: Repeatability (0.4%) and stability under continuous gamma irradiation (0.3%) are very good, in spite of low active volume and sensitivity (∼200pC/Gy). Charge collection efficiency is higher than 99% already at 150V with ∼2mGy dose per pulse, leading to a ±1.1% sensitivity change with dose per pulse in the range 0.09-2mGy (covering all flattened and unflattened applications). Measured dose profiles are in agreement with MatriXX for fields larger than 2×2cm{sup 2}, in which case the linear array offers a much better characterization of the penumbra region. Down to 1×1cm{sup 2}, measured profiles are in very good agreement with the flat panel. Conclusion: The array represents a valuable tool for the characterization of treatment fields in which high spatial resolution is required, together with the dosimetric performance of air vented ionization chambers. Such a technology would be particularly valuable in association with advanced treatment modalities such as rotational radiotherapy, stereotactic treatments (even with unflattened beam qualities) and proton therapy, due to the insensitivity of the chambers on dose per pulse. In the future, a two dimensional prototype based on this

  20. External Beam Radiotherapy in the Management of Low Grade Astrocytoma of the Brain

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Ha Jung [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2009-03-15

    This study was designed to evaluate the effectiveness of postoperative radiotherapy for patients with low-grade astrocytomas and to define an optimal radiotherapeutic regimen and prognostic factors. A total of 69 patients with low-grade astrocytomas underwent surgery and postoperative radiotherapy immediately following surgery at our institution between October 1989 and September 2006. The median patient age was 36 years. Forty-one patients were 40 years or younger and 28 patients were 41 years or older. Fourteen patients underwent a biopsy alone and the remaining 55 patients underwent a subtotal resection. Thirty-nine patients had a Karnofsky performance status of less than 80% and 30 patients had a Karnofsky performance status greater than 80%. Two patients were treated with whole brain irradiation followed by a coned down boost field to the localized area. The remaining 67 patients were treated with a localized field with an appropriate margin. Most of the patients received a dose of 50{approx}55 Gy and majority of the patients were treated with a dose of 54 Gy. The overall 5-year and 7-year survival rates for all of the 69 patients were 49% and 44%, respectively. Corresponding disease free survival rates were 45% and 40%, respectively. Patients who underwent a subtotal resection showed better survival than patients who underwent a biopsy alone. The overall 5-year survival rates for patients who underwent a subtotal resection and patients who underwent a biopsy alone were 57% and 38%, respectively (p<0.05). Forty-one patients who were 40 years or younger showed a better overall 5-year survival rate as compared with 28 patients who were 41 years or older (56% versus 40%, p<0.05). The overall 5-year survival rates for 30 patients with a Karnofsky performance status greater than 80% and 39 patients with a Karnofsky performance status less than 80% were 51% and 47%, respectively. This finding was not statistically significant. Although one patient was not able to

  1. Dose differences in intensity-modulated radiotherapy plans calculated with pencil beam and Monte Carlo for lung SBRT.

    Science.gov (United States)

    Liu, Han; Zhuang, Tingliang; Stephans, Kevin; Videtic, Gregory; Raithel, Stephen; Djemil, Toufik; Xia, Ping

    2015-01-01

    For patients with medically inoperable early-stage non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy, early treatment plans were based on a simpler dose calculation algorithm, the pencil beam (PB) calculation. Because these patients had the longest treatment follow-up, identifying dose differences between the PB calculated dose and Monte Carlo calculated dose is clinically important for understanding of treatment outcomes. Previous studies found significant dose differences between the PB dose calculation and more accurate dose calculation algorithms, such as convolution-based or Monte Carlo (MC), mostly for three-dimensional conformal radiotherapy (3D CRT) plans. The aim of this study is to investigate whether these observed dose differences also exist for intensity-modulated radiotherapy (IMRT) plans for both centrally and peripherally located tumors. Seventy patients (35 central and 35 peripheral) were retrospectively selected for this study. The clinical IMRT plans that were initially calculated with the PB algorithm were recalculated with the MC algorithm. Among these paired plans, dosimetric parameters were compared for the targets and critical organs. When compared to MC calculation, PB calculation overestimated doses to the planning target volumes (PTVs) of central and peripheral tumors with different magnitudes. The doses to 95% of the central and peripheral PTVs were overestimated by 9.7% ± 5.6% and 12.0% ± 7.3%, respectively. This dose overestimation did not affect doses to the critical organs, such as the spinal cord and lung. In conclusion, for NSCLC treated with IMRT, dose differences between the PB and MC calculations were different from that of 3D CRT. No significant dose differences in critical organs were observed between the two calculations. PMID:26699560

  2. The effects of intraoperative electron-beam radiotherapy on the incidence of postoperative complications in patients with unresectable pancreatic cancer

    International Nuclear Information System (INIS)

    Introduction. Intraoperative electron-beam radiotherapy (IOERT) may improve treatment results in patients with pancreatic cancer. However, due to the potential risk of damage to the tumor surrounding tissues, the key-element of the proposed treatment regimen is its safety evaluation. The aim of the study was to evaluate the safety of IOERT in patients with locally advanced, unresectable pancreatic cancer. Methods. The analysis of postoperative outcomes in 97 patients with locally advanced, unresectable pancreatic cancer, including 36 patients undergoing IOERT, was performed. Potential risk factors for postoperative morbidity were evaluated with univariate and multivariate analyses. Results. The IOERT significantly prolonged duration of surgery from 165 ±47 to 222 ±55 minutes (P=0.001) and increased the percentage of patients requiring blood transfusions (from 7% to 19%; P=0.053). Postoperative complications were found in 8 of 36 (22%) patients subjected to IOERT and 21 of 61 (34%) undergoing surgery without radiotherapy (P=0.204). Mortality rates were 3% and 8%, respectively. The incidence of surgical (IOERT 11%, no IOERT 20%; P=0.272) and general (IOERT 14%, no IOERT 20%; P=0.469) complications was similar in both groups. The multivariate analysis of potential variables influencing early postoperative outcome identified preoperative endoscopic biliary drainage (Odds Ratio 2.93; 95% CI 1.02-8.41) and enteric or biliary bypass procedure (Odds Ratio 3.84; 95% CI 1.24-11.97) as the only independent risk factors for complications. Conclusions. IOERT does not increase significantly the risk of postoperative complications in patients with locally advanced, unresectable pancreatic cancer. (authors)

  3. Beyond D’Amico risk classes for predicting recurrence after external beam radiotherapy for prostate cancer: the Candiolo classifier

    International Nuclear Information System (INIS)

    The aim of this work is to develop an algorithm to predict recurrence in prostate cancer patients treated with radical radiotherapy, getting up to a prognostic power higher than traditional D’Amico risk classification. Two thousand four hundred ninety-three men belonging to the EUREKA-2 retrospective multi-centric database on prostate cancer and treated with external-beam radiotherapy as primary treatment comprised the study population. A Cox regression time to PSA failure analysis was performed in univariate and multivariate settings, evaluating the predictive ability of age, pre-treatment PSA, clinical-radiological staging, Gleason score and percentage of positive cores at biopsy (%PC). The accuracy of this model was checked with bootstrapping statistics. Subgroups for all the variables’ combinations were combined to classify patients into five different “Candiolo” risk-classes for biochemical Progression Free Survival (bPFS); thereafter, they were also applied to clinical PFS (cPFS), systemic PFS (sPFS) and Prostate Cancer Specific Survival (PCSS), and compared to D’Amico risk grouping performances. The Candiolo classifier splits patients in 5 risk-groups with the following 10-years bPFS, cPFS, sPFS and PCSS: for very-low-risk 90 %, 94 %, 100 % and 100 %; for low-risk 74 %, 88 %, 94 % and 98 %; for intermediate-risk 60 %, 82 %, 91 % and 92 %; for high-risk 43 %, 55 %, 80 % and 89 % and for very-high-risk 14 %, 38 %, 56 % and 70 %. Our classifier outperforms D’Amico risk classes for all the end-points evaluated, with concordance indexes of 71.5 %, 75.5 %, 80 % and 80.5 % versus 63 %, 65.5 %, 69.5 % and 69 %, respectively. Our classification tool, combining five clinical and easily available parameters, seems to better stratify patients in predicting prostate cancer recurrence after radiotherapy compared to the traditional D’Amico risk classes. The online version of this article (doi:10.1186/s13014-016-0599-5) contains supplementary material, which

  4. Development of a magnetic beam guiding system for tumor-specific radiotherapy using heavy, charged particles

    International Nuclear Information System (INIS)

    An active, magnetic beam guiding system was developed and tested for the purpose of enhanced and tumor-specific irradiation of irregularly shaped target volumina. Combining intensity-controlled wobbling in rapidly changing magnetic fields with the heavy-ion synchrotron's capacity of fast energy variation achieved a new technique allowing good range modulation. This technique allows the calculated dose distribution to be exactly matched to target contours, and at the same time guarantees best possible quality of the radiation beam, since there is no need for use of mechanical beam shaping members. The components of the scanning system and a specifically designed instrumentation and control concept for this configuration were integrated into the synchrotron's control system, so that there is now a system available offering free selection of beam characteristics combined with energy variation along with the pulsed operation of the accelerator. The system was tested at the biophysical measuring unit of the GSI implementing an elaborated irradiation method at this unit equipped with tools for physico-technical irradiation planning and performance. Methods were designed and tested for optimizing the beam path within a given contour, the optimization taking into account the effects of transmission functions of the scanner components on the results of radiation treatments. (orig.)

  5. Monte Carlo investigations of the effect of beam divergence on thick, segmented crystalline scintillators for radiotherapy imaging

    Science.gov (United States)

    Wang, Yi; El-Mohri, Youcef; Antonuk, Larry E.; Zhao, Qihua

    2010-07-01

    The use of thick, segmented scintillators in electronic portal imagers offers the potential for significant improvement in x-ray detection efficiency compared to conventional phosphor screens. Such improvement substantially increases the detective quantum efficiency (DQE), leading to the possibility of achieving soft-tissue visualization at clinically practical (i.e. low) doses using megavoltage (MV) cone-beam computed tomography. While these DQE increases are greatest at zero spatial frequency, they are diminished at higher frequencies as a result of degradation of spatial resolution due to lateral spreading of secondary radiation within the scintillator—an effect that is more pronounced for thicker scintillators. The extent of this spreading is even more accentuated for radiation impinging the scintillator at oblique angles of incidence due to beam divergence. In this paper, Monte Carlo simulations of radiation transport, performed to investigate and quantify the effects of beam divergence on the imaging performance of MV imagers based on two promising scintillators (BGO and CsI:Tl), are reported. In these studies, 10-40 mm thick scintillators, incorporating low-density polymer, or high-density tungsten septal walls, were examined for incident angles corresponding to that encountered at locations up to ~15 cm from the central beam axis (for an imager located 130 cm from a radiotherapy x-ray source). The simulations demonstrate progressively more severe spatial resolution degradation (quantified in terms of the effect on the modulation transfer function) as a function of increasing angle of incidence (as well as of the scintillator thickness). Since the noise power behavior was found to be largely independent of the incident angle, the dependence of the DQE on the incident angle is therefore primarily determined by the spatial resolution. The observed DQE degradation suggests that 10 mm thick scintillators are not strongly affected by beam divergence for

  6. Patterns of Radiotherapy Practice for Patients With Cervical Cancer in Japan, 2003-2005: Changing Trends in the Pattern of Care Process

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Natsuo, E-mail: ntomita@aichi-cc.jp [Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya (Japan); Toita, Takafumi [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Okinawa (Japan); Kodaira, Takeshi [Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya (Japan); Shinoda, Atsunori [Department of Radiology, Shinshu University School of Medicine, Matsumoto (Japan); Uno, Takashi [Department of Radiology, Graduate School of Medicine, Chiba University, Chiba (Japan); Numasaki, Hodaka; Teshima, Teruki [Department of Medical Physics and Engineering, Graduate School of Medicine, Osaka University, Suita (Japan); Mitsumori, Michihide [Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto (Japan)

    2012-08-01

    Purpose: The patterns of care study (PCS) of radiotherapy for cervical cancer in Japan over the last 10 years was reviewed. Methods and Materials: The Japanese PCS working group analyzed data from 1,200 patients (1995-1997, 591 patients; 1999-2001, 324 patients; 2003-2005, 285 patients) with cervical cancer treated with definitive radiotherapy in Japan. Results: Patients in the 2001-2003 survey were significantly younger than those in the 1999-2001 study (p < 0.0001). Histology, performance status, and International Federation of Gynecology and Obstetrics stage were not significantly different among the three survey periods. Use of combinations of chemotherapy has increased significantly during those periods (1995-1997, 24%; 1999-2001, 33%; 2003-2005, 54%; p < 0.0001). The ratio of patients receiving concurrent chemotherapy has also dramatically increased (1995-1997, 20%; 1999-2001, 54%; 2003-2005, 83%; p < 0.0001). As for external beam radiotherapy (EBRT), the application rate of four-field portals has greatly increased over the three survey periods (1995-1997, 2%; 1999-2001, 7%; 2003-2005, 21%; p < 0.0001). In addition, the use of an appropriate beam energy for EBRT has shown an increase (1995-1997, 67%; 1999-2001, 74%; 2003-2005, 81%; p = 0.064). As for intracavitary brachytherapy (ICBT), an iridium source has become increasingly popular (1995-1997, 27%; 1999-2001, 42%; 2003-2005, 84%; p < 0.0001). Among the three surveys, the ratio of patients receiving ICBT (1995-1997, 77%; 1999-2001, 82%; 2003-2005, 78%) has not changed. Although follow-up was inadequate in each survey, no significant survival differences were observed (p = 0.36), and rates of late Grade 3 or higher toxicity were significantly different (p = 0.016). Conclusions: The Japanese PCS has monitored consistent improvements over the past 10 years in the application of chemotherapy, timing of chemotherapy, and EBRT methods. However, there is still room for improvement, especially in the clinical

  7. Patient safety in external beam radiotherapy – Guidelines on risk assessment and analysis of adverse error-events and near misses: Introducing the ACCIRAD project

    International Nuclear Information System (INIS)

    In 2011 the European Commission launched a tender to develop guidelines for risk analysis of accidental and unintended exposures in external beam radiotherapy. This tender was awarded to a consortium of 6 institutions, including the ESTRO, in late 2011. The project, denominated “ACCIRAD”, recently finished the data collection phase. Data were collected by surveys administered in 38 European countries. Results indicate non-uniform implementation of event registration and classification, as well as incomplete or zero implementation of risk assessment and events analysis. Based on the survey results and analysis thereof, project leaders are currently drafting proposed guidelines entitled “Guidelines for patient safety in external beam radiotherapy – Guidelines on risk assessment and analysis of adverse-error events and near misses”. The present article describes the aims and current status of the project, including results of the surveys

  8. Magnetic fields and beam optics studies of a 250 MeV superconducting proton radiotherapy cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Won [Research Institute and Hospital, National Cancer Center, 809 Madu-dong, Koyang, Kyonggi (Korea, Republic of)], E-mail: jwkim@ncc.re.kr

    2007-11-21

    A 250 MeV superconducting cyclotron for the proton radiation therapy was designed at the Michigan State University (MSU) for use at the Paul Scherrer Institut. This work was based on the conceptual design carried out at the MSU in 1994. The previous design was refined to finalize the magnet configuration and to optimally arrange cyclotron elements for the actual construction. The spiral angle of the pole was reduced, the new hill-edges and valley shims being introduced. The magnetic fields were highly isochronized using a least square fitting routine involving a schematic shimming scheme. The resulting reference field was adequate for the elaborate study of beam optics. The optics simulation predicted that extraction efficiency of above 80% was achievable for a beam with the initial phase width of 20{sup o}. The vertical deflector was investigated located in the central region to control the beam intensity with tracking of beam phase spaces. Some measurement results for the constructed cyclotron were found in a good agreement with those of the optics study.

  9. Monte Carlo Commissioning of Low Energy Electron Radiotherapy Beams using NXEGS Software

    Directory of Open Access Journals (Sweden)

    2004-06-01

    Full Text Available This work is a report on the commissioning of low energy electron beams of a medical linear accelerator for Monte Carlo dose calculation using NXEGS software (NXEGS version 1.0.10.0, NX Medical Software, LLC. A unique feature of NXEGS is automated commissioning, a process whereby a combination of analytic and Monte Carlo methods generates beam models from dosimetric data collected in a water phantom. This study uses NXEGS to commission 6, 9, and 12 MeV electron beams of a Varian Clinac 2100C using three applicators with standard inserts. Central axis depth-dose, primary axis and diagonal beam profiles, and output factors are the measurements necessary for commissioning of the code. We present a comparison of measured dose distributions with the distributions generated by NXEGS, using confidence limits on seven measures of error. We find that confidence limits are typically less than 3% or 3 mm, but increase with increasing source to surface distance (SSD and depth at or beyond R50. We also investigate the dependence of NXEGS' performance on the size and composition of data used to commission the program, finding a weak dependence on number of dose profiles in the data set, but finding also that commissioning data need be measured at only two SSDs.

  10. A procedure for calculation of monitor units for passively scattered proton radiotherapy beams.

    Science.gov (United States)

    Sahoo, Narayan; Zhu, X Ronald; Arjomandy, Bijan; Ciangaru, George; Lii, MingFwu; Amos, Richard; Wu, Richard; Gillin, Michael T

    2008-11-01

    The purpose of this study is to validate a monitor unit (MU) calculation procedure for passively scattered proton therapy beams. The output dose per MU (d/MU) of a therapeutic radiation beam is traditionally calibrated under specific reference conditions. These conditions include beam energy, field size, suitable depth in water or water equivalent phantom in a low dose gradient region with known relative depth dose, and source to point of calibration distance. Treatment field settings usually differ from these reference conditions leading to a different d/MU that needs to be determined for delivering the prescribed dose. For passively scattered proton beams, the proton specific parameters, which need to be defined, are related to the energy, lateral scatterers, range modulating wheel, spread out Bragg peak (SOBP) width, thickness of any range shifter, the depth dose value relative to the normalization point in the SOBP, and scatter both from the range compensator and inhomogeneity in the patient. Following the custom for photons or electrons, a set of proton dosimetry factors, representing the changes in the d/MU relative to a reference condition, can be defined as the relative output factor (ROF), SOBP factor (SOBPF), range shifter factor (RSF), SOBP off-center factor (SOBPOCF), off-center ratio (OCR), inverse square factor (ISF), field size factor (FSF), and compensator and patient scatter factor (CPSF). The ROF, SOBPF, and RSF are the major contributors to the d/MU and were measured using an ion chamber in water tank during the clinical commissioning of each beam to create a dosimetry beam data table to be used for calculating the monitor units. The following simple formula is found to provide an independent method to determine the d/MU at the point of interest (POI) in the patient, namely, (d/MU) = ROF SOBPF. RSF SOBPOCF.OCR.FSF.ISF.CPSF. The monitor units for delivering the intended dose (D) to the POI can be obtained from MU = D / (d/MU). The accuracy and

  11. Dosimetric consequences of tumor volume changes after kilovoltage cone-beam computed tomography for non-operative lung cancer during adaptive intensity-modulated radiotherapy or fractionated stereotactic radiotherapy

    Institute of Scientific and Technical Information of China (English)

    Jian Hu; Ximing Xu; Guangjin Yuan; Wei Ge; Liming Xu; Aihua Zhang; Junjian Deng

    2015-01-01

    Objective The aim of this study was to investigate tumor volume changes with kilovoltage cone-beam computed tomography (kV-CBCT) and their dosimetric consequences for non-operative lung cancer during intensity-modulated radiotherapy (IMRT) or fractionated stereotactic radiotherapy. Methods Eighteen patients with non-operative lung cancer who received IMRT consisting of 1.8-2.2 Gy/fraction and five fractions per week or stereotactic radiotherapy with 5-8 Gy/fraction and three fractions a week were studied. kV-CBCT was performed once per week during IMRT and at every fraction during stereotactic radiotherapy. The gross tumor volume (GTV) was contoured on the kV-CBCT images, and adaptive treatment plans were created using merged kV-CBCT and primary planning computed tomogra-phy image sets. Tumor volume changes and dosimetric parameters, including the minimum dose to 95%(D95) or 1% (D1) of the planning target volume (PTV), mean lung dose (MLD), and volume of lung tissue that received more than 5 (V5), 10 (V10), 20 (V20), and 30 (V30) Gy were retrospectively analyzed. Results The average maximum change in GTV observed during IMRT or fractionated stereotactic radio-therapy was -25.85% (range, -13.09% --56.76%). The D95 and D1 of PTV for the adaptive treatment plans in all patients were not significantly different from those for the initial or former adaptive treatment plans. In patients with tumor volume changes of >20% in the third or fourth week of treatment during IMRT, adap-tive treatment plans offered clinically meaningful decreases in MLD and V5, V10, V20, and V30; however, in patients with tumor volume changes of 20% in the third or fourth week of treatment.

  12. On the feasibility of dose quantification with in-beam PET data in radiotherapy with {sup 12}C and proton beams

    Energy Technology Data Exchange (ETDEWEB)

    Parodi, K.

    2004-11-01

    The physical advantages of light ions in combination with technological advances like intensity controlled raster scanning offer a unique tool for high precision radiotherapy. This is particularly applied to delicate clinical situations of inoperable tumours growing in close proximity to critical organs. The potential benefit of such a high selectivity of ion beam therapy demands the complex and strictly conformal dose delivery to be monitored in-situ and non-invasively in three dimensions. In contrast to conventional photon radiation, light ions exhibit a well defined range which determines the position of the maximum dose delivery in the inhomogeneous tumour target. This requires a monitoring technology along the ion trajectory offering millimetre precision. Additionally, accurate control of the lateral position of the irradiation field within the patient can be a crucial issue for the frequent case of portals passing adjacent to organs at risk. At present, positron emission tomography (PET) represents the only feasible method fulfilling these requirements. For this purpose a dedicated in-beam positron camera has been completely integrated into the experimental heavy ion treatment site at the Gesellschaft fuer Schwerionenforschung (GSI) Darmstadt. This allows to measure the minor amount of {beta}{sup +}-activity produced in nuclear reactions between the projectiles and the target nuclei of the tissue simultaneously to the tumour irradiation. The emitted signal is correlated but not directly proportional to the spatial pattern of the delivered dose. Hence, therapy control is achieved by comparing the measured {beta}{sup +}-activity distribution with a prediction based on the treatment plan and the specific time course of the particular irradiation. (orig.)

  13. Volumetric Modulated Arc Therapy for Spine Radiosurgery: Superior Treatment Planning and Delivery Compared to Static Beam Intensity Modulated Radiotherapy

    Directory of Open Access Journals (Sweden)

    Leor Zach

    2016-01-01

    Full Text Available Purpose. Spine stereotactic radiosurgery (SRS delivers an accurate and efficient high radiation dose to vertebral metastases in 1–5 fractions. We aimed to compare volumetric modulated arc therapy (VMAT to static beam intensity modulated radiotherapy (IMRT for spine SRS. Methods and Materials. Ten spine lesions of previously treated SRS patients were planned retrospectively using both IMRT and VMAT with a prescribed dose of 16 Gy to 100% of the planning target volume (PTV. The plans were compared for conformity, homogeneity, treatment delivery time, and safety (spinal cord dose. Results. All evaluated parameters favored the VMAT plan over the IMRT plans. Dmin in the IMRT was significantly lower than in the VMAT plan (7.65 Gy/10.88 Gy, p<0.001, the Dice Similarity Coefficient (DSC was found to be significantly better for the VMAT plans compared to the IMRT plans (0.77/0.58, resp., p  value<0.01, and an almost 50% reduction in the net treatment time was calculated for the VMAT compared to the IMRT plans (6.73 min/12.96 min, p<0.001. Conclusions. In our report, VMAT provides better conformity, homogeneity, and safety profile. The shorter treatment time is a major advantage and not only provides convenience to the painful patient but also contributes to the precision of this high dose radiation therapy.

  14. Postprostatectomy ultrasound-guided transrectal implantation of gold markers for external beam radiotherapy. Technique and complications rate

    Energy Technology Data Exchange (ETDEWEB)

    Langenhuijsen, J.F.; Kiemeney, L.A.L.M.; Witjes, J.A. [Radboud Univ. Nijmegen Medical Center, Nijmegen (Netherlands). Dept. of Urology; Donker, R. [Medical Center Alkmaar (Netherlands). Dept. of Radiation Oncology; McColl, G.M.; Lin, E.N.J.T. van [Radboud Univ. Nijmegen Medical Center, Nijmegen (Netherlands). Dept. of Radiation Oncology

    2013-06-15

    Background and purpose: Postprostatectomy radiotherapy (RT) improves survival in adjuvant and salvage settings. The implantation technique and complications rate of gold markers in the prostate bed for high-precision RT were analyzed. Patients and methods: Patients undergoing postprostatectomy RT for prostate-specific antigen (PSA) relapse or high-risk disease were enrolled in the study. Under transrectal ultrasound guidance, three fine gold markers were implanted in the prostate bed and the technical difficulties of insertion were documented. Patients received our self-designed questionnaires concerning complications and pain. The influence of anticoagulants and coumarins on bleeding was analyzed, as was the effect of potential risk factors on pain. Results: In 77 consecutive patients, failure of marker implantation or marker migration was seen in six cases. Rectal bleeding was reported by 10 patients and 1 had voiding complaints. No macroscopic hematuria persisting for more than 3 days was observed. Other complications included rectal discomfort (n = 2), nausea (n = 1), abdominal discomfort (n = 1), and pain requiring analgesics (n = 4). No major complications were reported. On a 0-10 visual analogue scale (VAS), the mean pain score was 3.7. No clinically significant risk factors for complications were identified. Conclusion: Transrectal implantation of gold markers in the prostate bed is feasible and safe. Alternatives like cone beam computed tomography (CBCT) should be considered, but the advantages of gold marker implantation for high-precision postprostatectomy RT would seem to outweigh the minor risks involved. (orig.)

  15. A GPU-based finite-size pencil beam algorithm with 3D-density correction for radiotherapy dose calculation

    Science.gov (United States)

    Gu, Xuejun; Jelen, Urszula; Li, Jinsheng; Jia, Xun; Jiang, Steve B.

    2011-06-01

    Targeting at the development of an accurate and efficient dose calculation engine for online adaptive radiotherapy, we have implemented a finite-size pencil beam (FSPB) algorithm with a 3D-density correction method on graphics processing unit (GPU). This new GPU-based dose engine is built on our previously published ultrafast FSPB computational framework (Gu et al 2009 Phys. Med. Biol. 54 6287-97). Dosimetric evaluations against Monte Carlo dose calculations are conducted on ten IMRT treatment plans (five head-and-neck cases and five lung cases). For all cases, there is improvement with the 3D-density correction over the conventional FSPB algorithm and for most cases the improvement is significant. Regarding the efficiency, because of the appropriate arrangement of memory access and the usage of GPU intrinsic functions, the dose calculation for an IMRT plan can be accomplished well within 1 s (except for one case) with this new GPU-based FSPB algorithm. Compared to the previous GPU-based FSPB algorithm without 3D-density correction, this new algorithm, though slightly sacrificing the computational efficiency (~5-15% lower), has significantly improved the dose calculation accuracy, making it more suitable for online IMRT replanning.

  16. A method to separate the rectum from the prostate during proton beam radiotherapy of prostate cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Isacsson, Ulf; Nilsson, Kristina; Asplund, Stefan; Morhed, Elizabeth; Montelius, Anders; Turesson, Ingela (Sections of Oncology and Medical Radiation Physics, Dept. of Oncology, Radiology and Clinical Immunology, Uppsala Univ. Hospital, Uppsala (Sweden)), E-mail: ulf.isacsson@akademiska.se

    2010-05-15

    The use of protons for curative treatment of prostate cancer is increasing, either as a single treatment modality or in combination with conventional radiotherapy. The proximity between prostate (target) and rectum (organ at risk) often leads to a compromise between dose to target and organ at risk. Material and methods. The present study describes a method where the distance between prostate and rectum is increased by retraction of the rectum in dorsal direction. Comparative treatment plans with and without retraction of the rectum in the same patients have been studied. Nine patients with biopsy proven, localised adenocarcinoma of the prostate were studied. A cylindrical rod of Perspex was inserted into the rectum. This device allows the rectum to be retracted posteriorly. The patients were given a proton boost of 20 Gy in four fractions of 5 Gy in addition to a conventional photon beam treatment to a dose of 50 Gy in 25 fractions of 2 Gy. Results. Comparative treatment planning shows that the treatment plan with rectal retraction significantly reduces (p<0.01) the volume of the rectal wall receiving high doses (equal to 70 Gy in 2 Gy fractions) in all patients. Conclusions. The proton boost treatment with retraction of rectum during treatment decreases the rectal dose substantially. This is expected to reduce rectal side effects

  17. Enteric-coated, highly standardized cranberry extract reduces risk of UTIs and urinary symptoms during radiotherapy for prostate carcinoma

    Science.gov (United States)

    Bonetta, Alberto; Di Pierro, Francesco

    2012-01-01

    Background Cranberry (Vaccinium macrocarpon) proanthocyanidins can interfere with adhesion of bacteria to uroepithelial cells, potentially preventing lower urinary tract infections (LUTIs). Because LUTIs are a common side effect of external beam radiotherapy (EBRT) for prostate cancer, we evaluated the clinical efficacy of enteric-coated tablets containing highly standardized V. msacrocarpon (ecVM) in this condition. Methods A total of 370 consecutive patients were entered into this study. All patients received intensity-modulated radiotherapy for prostate cancer; 184 patients were also treated with ecVM while 186 served as controls. Cranberry extract therapy started on the simulation day, at which time a bladder catheterization was performed. During EBRT (over 6–7 weeks), all patients underwent weekly examination for urinary tract symptoms, including regular urine cultures during the treatment period. Results Compliance was excellent, with no adverse effects or allergic reactions being observed, apart from gastric pain in two patients. In the cranberry cohort (n = 184), 16 LUTIs (8.7%) were observed, while in the control group (n = 186) 45 LUTIs (24.2%) were recorded. This difference was statistically significant. Furthermore, lower rates of nocturia, urgency, micturition frequency, and dysuria were observed in the group that received cranberry extract. Conclusion Cranberry extracts have been reported to reduce the incidence of LUTIs significantly in women and children. Our data extend these results to patients with prostate cancer undergoing irradiation to the pelvis, who had a significant reduction in LUTIs compared with controls. These results were accompanied by a statistically significant reduction in urinary tract symptoms (dysuria, nocturia, urinary frequency, urgency), suggesting a generally protective effect of cranberry extract on the bladder mucosa. PMID:22977312

  18. Prognostic analysis of uterine cervical cancer treated with postoperative radiotherapy: importance of positive or close parametrial resection margin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yi Jun; Lee, Kyung Ja; Park, Kyung Ran [Dept. of Radiation Oncology, (Korea, Republic of); and others

    2015-06-15

    To analyze prognostic factors for locoregional recurrence (LRR), distant metastasis (DM), and overall survival (OS) in cervical cancer patients who underwent radical hysterectomy followed by postoperative radiotherapy (PORT) in a single institute. Clinicopathologic data of 135 patients with clinical stage IA2 to IIA2 cervical cancer treated with PORT from 2001 to 2012 were reviewed, retrospectively. Postoperative parametrial resection margin (PRM) and vaginal resection margin (VRM) were investigated separately. The median treatment dosage of external beam radiotherapy (EBRT) to the whole pelvis was 50.4 Gy in 1.8 Gy/fraction. High-dose-rate vaginal brachytherapy after EBRT was given to patients with positive or close VRMs. Concurrent platinum-based chemoradiotherapy (CCRT) was administered to 73 patients with positive resection margin, lymph node (LN) metastasis, or direct extension of parametrium. Kaplan-Meier method and log-rank test were used for analyzing LRR, DM, and OS; Cox regression was applied to analyze prognostic factors. The 5-year disease-free survival was 79% and 5-year OS was 91%. In univariate analysis, positive or close PRM, LN metastasis, direct extension of parametrium, lymphovascular invasion, histology of adenocarcinoma, and chemotherapy were related with more DM and poor OS. In multivariate analysis, PRM and LN metastasis remained independent prognostic factors for OS. PORT after radical hysterectomy in uterine cervical cancer showed excellent OS in this study. Positive or close PRM after radical hysterectomy in uterine cervical cancer correlates with poor prognosis even with CCRT. Therefore, additional treatments to improve local control such as radiation boosting need to be considered.

  19. Broad-beam three-dimensional irradiation system for heavy-ion radiotherapy at HIMAC

    CERN Document Server

    Futami, Y; Fujita, M; Tomura, H; Higashi, A; Matsufuji, N; Miyahara, N; Endo, M; Kawachi, K

    1999-01-01

    A three-dimensional irradiation system using a broad beam has been installed for heavy-ion cancer therapy at the Heavy Ion Medical Accelerator in Chiba (HIMAC) facility. Only the target region is irradiated at the 100% dose level; the dose level at other parts of irradiated tissues is less, using a range shifter, a multileaf collimator and a compensator. The devices are the same as those used in two-dimensional irradiation, except that the setting values of the devices can be dynamically changed during the treatment. The thickness of the absorber and the aperture of the multileaf collimator are dynamically controlled during irradiation, so that the Bragg peak is swept in the depth direction and the Bragg peak outside of the target volume is blocked by the multileaf collimator. The performance of this system was checked by irradiation of a phantom using a 290 MeV/nucleon carbon beam. The dose distribution realized by this three-dimensional irradiation agreed satisfactorily with the planned one.

  20. A hybrid algorithm for instant optimization of beam weights in anatomy-based intensity modulated radiotherapy: a performance evaluation study

    International Nuclear Information System (INIS)

    The study aims to introduce a hybrid optimization algorithm for anatomy-based intensity modulated radiotherapy (AB-IMRT). Our proposal is that by integrating an exact optimization algorithm with a heuristic optimization algorithm, the advantages of both the algorithms can be combined, which will lead to an efficient global optimizer solving the problem at a very fast rate. Our hybrid approach combines Gaussian elimination algorithm (exact optimizer) with fast simulated annealing algorithm (a heuristic global optimizer) for the optimization of beam weights in AB-IMRT. The algorithm has been implemented using MATLAB software. The optimization efficiency of the hybrid algorithm is clarified by (i) analysis of the numerical characteristics of the algorithm and (ii) analysis of the clinical capabilities of the algorithm. The numerical and clinical characteristics of the hybrid algorithm are compared with Gaussian elimination method (GEM) and fast simulated annealing (FSA). The numerical characteristics include convergence, consistency, number of iterations and overall optimization speed, which were analyzed for the respective cases of 8 patients. The clinical capabilities of the hybrid algorithm are demonstrated in cases of (a) prostate and (b) brain. The analyses reveal that (i) the convergence speed of the hybrid algorithm is approximately three times higher than that of FSA algorithm (ii) the convergence (percentage reduction in the cost function) in hybrid algorithm is about 20% improved as compared to that in GEM algorithm (iii) the hybrid algorithm is capable of producing relatively better treatment plans in terms of Conformity Index (CI) (∼ 2% - 5% improvement) and Homogeneity Index (HI) (∼ 4% - 10% improvement) as compared to GEM and FSA algorithms (iv) the sparing of organs at risk in hybrid algorithm-based plans is better than that in GEM-based plans and comparable to that in FSA-based plans; and (v) the beam weights resulting from the hybrid algorithm are

  1. Fifteen symposia on microdosimetry: implications for modern particle-beam cancer radiotherapy

    CERN Document Server

    Wambersie, A; Gueulette, J; Pihet, P

    2015-01-01

    The objective of microdosimetry was, and still is, to identify physical descriptions of the initial physical processes of ionising radiation interacting with biological matter which correlate with observed radiobiological effects with a view to improve the understanding of radiobiological mechanisms and effects. The introduction of therapy with particles starting with fast neutrons followed by negative pions, protons and light ions necessitated the application of biological weighting factors for absorbed dose in order to account for differences of the relative biological effectiveness (RBE). Dedicated radiobiological experiments in therapy beams with mammalian cells and with laboratory animals provided sets of RBE values which are used to evaluate empirical ‘clinical RBE values’. The combination of such experiments with microdosimetric measurements in identical conditions offered the possibility to establish semi-empirical relationships between microdosimetric parameters and results of RBE studies.

  2. Dose-response characteristics of low- and intermediate-risk prostate cancer treated with external beam radiotherapy

    International Nuclear Information System (INIS)

    Purpose: In this era of dose escalation, the benefit of higher radiation doses for low-risk prostate cancer remains controversial. For intermediate-risk patients, the data suggest a benefit from higher doses. However, the quantitative characterization of the benefit for these patients is scarce. We investigated the radiation dose-response relation of tumor control probability in low-risk and intermediate-risk prostate cancer patients treated with radiotherapy alone. We also investigated the differences in the dose-response characteristics using the American Society for Therapeutic Radiology and Oncology (ASTRO) definition vs. an alternative biochemical failure definition. Methods and materials: This study included 235 low-risk and 387 intermediate-risk prostate cancer patients treated with external beam radiotherapy without hormonal treatment between 1987 and 1998. The low-risk patients had 1992 American Joint Committee on Cancer Stage T2a or less disease as determined by digital rectal examination, prostate-specific antigen (PSA) levels of ≤10 ng/mL, and biopsy Gleason scores of ≤6. The intermediate-risk patients had one or more of the following: Stage T2b-c, PSA level of ≤20 ng/mL but >10 ng/mL, and/or Gleason score of 7, without any of the following high-risk features: Stage T3 or greater, PSA >20 ng/mL, or Gleason score ≥8. The logistic models were fitted to the data at varying points after treatment, and the dose-response parameters were estimated. We used two biochemical failure definitions. The ASTRO PSA failure was defined as three consecutive PSA rises, with the time to failure backdated to the mid-point between the nadir and the first rise. The second biochemical failure definition used was a PSA rise of ≥2 ng/mL above the current PSA nadir (CN + 2). The failure date was defined as the time at which the event occurred. Local, nodal, and distant relapses and the use of salvage hormonal therapy were also failures. Results: On the basis of the

  3. External-beam radiation therapy should be given with androgen deprivation treatment for intermediate-risk nrnstate cancer: new confirmatory evidence

    Institute of Scientific and Technical Information of China (English)

    Matthew R Cooperberg

    2012-01-01

    Anewly published study, RadiationTherapy Oncology Group (RTOG) trial94-08,has demonstrated that a short-course ofneoadjuvant androgen deprivation therapy (ADT) given together with external-beam radiation therapy (EBRT) improves outcomes for men with intermediate-risk prostate cancer compared with EBRT alone.

  4. Increasing Use of Dose-Escalated External Beam Radiation Therapy for Men With Nonmetastatic Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Swisher-McClure, Samuel, E-mail: Swisher-Mcclure@uphs.upenn.edu [Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States); Leonard Davis Institute of Health Economics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States); Mitra, Nandita; Woo, Kaitlin [Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Smaldone, Marc; Uzzo, Robert [Division of Urologic Oncology, Department of Surgery, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA (United States); Bekelman, Justin E. [Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States); Leonard Davis Institute of Health Economics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA (United States); Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2014-05-01

    Purpose: To examine recent practice patterns, using a large national cancer registry, to understand the extent to which dose-escalated external beam radiation therapy (EBRT) has been incorporated into routine clinical practice for men with prostate cancer. Methods and Materials: We conducted a retrospective observational cohort study using the National Cancer Data Base, a nationwide oncology outcomes database in the United States. We identified 98,755 men diagnosed with nonmetastatic prostate cancer between 2006 and 2011 who received definitive EBRT and classified patients into National Comprehensive Cancer Network (NCCN) risk groups. We defined dose-escalated EBRT as total prescribed dose of ≥75.6 Gy. Using multivariable logistic regression, we examined the association of patient, clinical, and demographic characteristics with the use of dose-escalated EBRT. Results: Overall, 81.6% of men received dose-escalated EBRT during the study period. The use of dose-escalated EBRT did not vary substantially by NCCN risk group. Use of dose-escalated EBRT increased from 70.7% of patients receiving treatment in 2006 to 89.8% of patients receiving treatment in 2011. On multivariable analysis, year of diagnosis and use of intensity modulated radiation therapy were significantly associated with receipt of dose-escalated EBRT. Conclusions: Our study results indicate that dose-escalated EBRT has been widely adopted by radiation oncologists treating prostate cancer in the United States. The proportion of patients receiving dose-escalated EBRT increased nearly 20% between 2006 and 2011. We observed high utilization rates of dose-escalated EBRT within all disease risk groups. Adoption of intensity modulated radiation therapy was strongly associated with use of dose-escalated treatment.

  5. SU-E-T-211: Induced Release of Nanocarrier Encapsulated Chemotherapeutic Drugs Using Proton Radiotherapy Beams

    Energy Technology Data Exchange (ETDEWEB)

    Polf, J; Jackson, I [University of Maryland School of Medicine, Baltimore, MD (United States); Ranjan, A; Fernando, R [Oklahoma State University, Stillwater, OK (United States); Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States)

    2014-06-01

    Purpose: The purpose of this work was to develop and validate an open source independent MU dose calculation software for S and S IMRT based in the algorithm proposed by Kung et.al. Methods: Treatment plans were done using Iplan v4.5 BrainLAB TPS and S and S IMRT modality. A 6MV photon beam produced by a Primus linear accelerator equipped with an Optifocus MLC was used. TPS dose calculation algorithms were pencil beam and Monte Carlo. 230 IMRT treatments plans were selected for the study. The software was written under MALTLAB environment. Treatment plans were imported by the software using RTP format. Field fluences were reconstructed adding all segments.The algorithm implemented in the software calculates the dose at a reference point as the sum of primary and scatter dose. The primary dose is obtained by masking the fluence map with a circle of radius 1cm. The scatter dose is obtained through a shaped ring mask around the previous circle with a thickness of 0.5cm; the rings are increased one after another with constant thickness until cover the entire map of influence. The dosimetric parameters Sc, Sp and TPR vary depending on radio, the transmission effect of the MLC, inverse square law and dose profile are used for the calculation. Results: The average difference between measured and independent calculated dose was 0.4% ± 2.2% [−6.8%, 6.4%]. For 91% of the studied plans the difference was less than 3%. The difference between the measured and TPS dose with pencilbeam algorithm was 2.6% ± 1.41% [−2.0%, 5.6%] and Monte Carlo algorithm was 0.4% ± 1.5% [−4.9%, 3.7%]. The differences obtained are comparable to that obtained with the ionization chamber and TPS. Conclusion: The developed software is suitable for use in S and S IMRT dose calculation. This application is open and can be downloading under request.

  6. Validation of an amino-acid-based radionuclide therapy plus external beam radiotherapy in heterotopic glioblastoma models

    Energy Technology Data Exchange (ETDEWEB)

    Israel, Ina [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany); Blass, Georg [Department of Radiotherapy and Radiooncology, Saarland University Medical Center, Homburg (Germany); Reiners, Christoph [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany); Samnick, Samuel, E-mail: samnick_s@klinik.uni-wuerzburg.d [Department of Nuclear Medicine, University of Wuerzburg, D-97080 Wuerzburg (Germany)

    2011-05-15

    Background and purpose: Malignant gliomas represent a major therapeutic challenge because no efficient treatment is currently available. p-[{sup 131}I]iodo-L-phenylalanine ([{sup 131}I]IPA) is a glioma avid radiopharmaceutical that demonstrated antiproliferative and tumoricidal effects in gliomas. The present study validated the therapeutic efficiency of [{sup 131}I]IPA combined with external beam radiotherapy in experimental gliomas. Materials and methods: Glioma cells derived from the primary human A1207, T5135, Tx3868 and M059K glioblastoma cell lines or rat F98 glioma cell line were treated with various doses of [{sup 131}I]IPA, external photon irradiation (RT) or combined [{sup 131}I]IPA/RT treatment. Responsiveness of glioma cells to the different therapy modalities was investigated at 24, 48 and 72 h after treatments by trypan blue, WST-1 assay, propidium iodide and bisbenzimide staining as well as by clonogenic assay. In addition, the therapy-induced DNA damage and repair were evaluated using phosphorylated histone H2AX ({gamma}-H2AX). In vivo, the effectiveness of the combination treatment was validated in human Tx3868 and A1207 glioblastoma xenografts in CD1 nu/nu mice and RNU rats. Results: In vitro, the combination treatment resulted in a greater than additive increase in cytotoxic effect in glioma cell lines. Cell survival rate following a treatment with 1.0 {mu}Ci (37 kBq) of [{sup 131}I]IPA amounted to 70%{+-}15% and 60%{+-}10% after 48 and 72 h, respectively, and decreased under 20% after additional RT with 5 Gy. At higher RT doses, cell survival rate decreased below 5%. As a measure of DNA double-strand break, nuclear {gamma}-H2AX foci were determined as a function of time. Within 24 h, the number of {gamma}-H2AX foci per cell was significantly greater after combined modality compared with the individual treatments. In vivo, when combined with RT, the radionuclide therapy with [{sup 131}I]IPA resulted in an extended tumor growth delay, a reduction

  7. Intensity-Modulated Radiotherapy Causes Fewer Side Effects than Three-Dimensional Conformal Radiotherapy When Used in Combination With Brachytherapy for the Treatment of Prostate Cancer

    International Nuclear Information System (INIS)

    Purpose: To measure the benefits of intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3D-CRT) when used in combination with brachytherapy for the treatment of prostate cancer. Methods and Materials: We conducted a retrospective review of all patients with localized prostate cancer who received external-beam radiotherapy (EBRT) in combination with brachytherapy with at least 1 year follow-up (n = 812). Combination therapy consisted of 103Pd or 125I implant, followed by a course of EBRT. From 1993 to March 2003 521 patients were treated with 3D-CRT, and from April 2003 to March 2009 291 patients were treated with IMRT. Urinary symptoms were prospectively measured with the International Prostate Symptom Score questionnaire with a single quality of life (QOL) question; rectal bleeding was assessed per the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. The Pearson χ2 test was used to compare toxicities experienced by patients who were treated with either IMRT or 3D-CRT. Logistic regression analyses were also performed to rule out possible confounding factors. Results: Within the first 3 months after treatment, patients treated with 3D-CRT scored their urinary symptoms as follows: 19% mild, 44% moderate, and 37% severe; patients treated with IMRT scored their urinary symptoms as follows: 36% mild, 47% moderate, and 17% severe (p < 0.001). The 3D-CRT patients rated their QOL as follows: 35% positive, 20% neutral, and 45% negative; IMRT patients rated their QOL as follows: 51% positive, 18% neutral, and 31% negative (p < 0.001). After 1 year of follow-up there was no longer any difference in urinary morbidity between the two groups. Logistic regression confirmed the differences in International Prostate Symptom Score and QOL in the acute setting (p < 0.001 for both). Grade ≥2 rectal bleeding was reported by 11% of 3D-CRT patients and 7% of

  8. Intensity-Modulated Radiotherapy Causes Fewer Side Effects than Three-Dimensional Conformal Radiotherapy When Used in Combination With Brachytherapy for the Treatment of Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Forsythe, Kevin; Blacksburg, Seth [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States); Stone, Nelson [Department of Urology, Mount Sinai School of Medicine, New York, NY (United States); Stock, Richard G., E-mail: richard.stock@moutsinai.org [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States)

    2012-06-01

    Purpose: To measure the benefits of intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3D-CRT) when used in combination with brachytherapy for the treatment of prostate cancer. Methods and Materials: We conducted a retrospective review of all patients with localized prostate cancer who received external-beam radiotherapy (EBRT) in combination with brachytherapy with at least 1 year follow-up (n = 812). Combination therapy consisted of {sup 103}Pd or {sup 125}I implant, followed by a course of EBRT. From 1993 to March 2003 521 patients were treated with 3D-CRT, and from April 2003 to March 2009 291 patients were treated with IMRT. Urinary symptoms were prospectively measured with the International Prostate Symptom Score questionnaire with a single quality of life (QOL) question; rectal bleeding was assessed per the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. The Pearson {chi}{sup 2} test was used to compare toxicities experienced by patients who were treated with either IMRT or 3D-CRT. Logistic regression analyses were also performed to rule out possible confounding factors. Results: Within the first 3 months after treatment, patients treated with 3D-CRT scored their urinary symptoms as follows: 19% mild, 44% moderate, and 37% severe; patients treated with IMRT scored their urinary symptoms as follows: 36% mild, 47% moderate, and 17% severe (p < 0.001). The 3D-CRT patients rated their QOL as follows: 35% positive, 20% neutral, and 45% negative; IMRT patients rated their QOL as follows: 51% positive, 18% neutral, and 31% negative (p < 0.001). After 1 year of follow-up there was no longer any difference in urinary morbidity between the two groups. Logistic regression confirmed the differences in International Prostate Symptom Score and QOL in the acute setting (p < 0.001 for both). Grade {>=}2 rectal bleeding was reported by 11% of 3D

  9. Radiotherapy of Cervical Cancer.

    Science.gov (United States)

    Vordermark, Dirk

    2016-01-01

    Curative-intent radical radiotherapy of cervical cancer consists of external-beam radiotherapy, brachytherapy, and concomitant chemotherapy with cisplatin. For each element, new developments aim to improve tumor control rates or treatment tolerance. Intensity-modulated radiotherapy (IMRT) has been shown to reduce gastrointestinal toxicity and can be used to selectively increase the radiotherapy dose. Individualized, image-guided brachytherapy enables better adaptation of high-dose volumes to the tumor extension. Intensification of concomitant or sequential systemic therapy is under evaluation. PMID:27614991

  10. Quantification and Assessment of Interfraction Setup Errors Based on Cone Beam CT and Determination of Safety Margins for Radiotherapy.

    Directory of Open Access Journals (Sweden)

    Macarena Cubillos Mesías

    Full Text Available To quantify interfraction patient setup-errors for radiotherapy based on cone-beam computed tomography and suggest safety margins accordingly.Positioning vectors of pre-treatment cone-beam computed tomography for different treatment sites were collected (n = 9504. For each patient group the total average and standard deviation were calculated and the overall mean, systematic and random errors as well as safety margins were determined.The systematic (and random errors in the superior-inferior, left-right and anterior-posterior directions were: for prostate, 2.5(3.0, 2.6(3.9 and 2.9(3.9mm; for prostate bed, 1.7(2.0, 2.2(3.6 and 2.6(3.1mm; for cervix, 2.8(3.4, 2.3(4.6 and 3.2(3.9mm; for rectum, 1.6(3.1, 2.1(2.9 and 2.5(3.8mm; for anal, 1.7(3.7, 2.1(5.1 and 2.5(4.8mm; for head and neck, 1.9(2.3, 1.4(2.0 and 1.7(2.2mm; for brain, 1.0(1.5, 1.1(1.4 and 1.0(1.1mm; and for mediastinum, 3.3(4.6, 2.6(3.7 and 3.5(4.0mm. The CTV-to-PTV margins had the smallest value for brain (3.6, 3.7 and 3.3mm and the largest for mediastinum (11.5, 9.1 and 11.6mm. For pelvic treatments the means (and standard deviations were 7.3 (1.6, 8.5 (0.8 and 9.6 (0.8mm.Systematic and random setup-errors were smaller than 5mm. The largest errors were found for organs with higher motion probability. The suggested safety margins were comparable to published values in previous but often smaller studies.

  11. Monte Carlo source model for photon beam radiotherapy: photon source characteristics

    International Nuclear Information System (INIS)

    A major barrier to widespread clinical implementation of Monte Carlo dose calculation is the difficulty in characterizing the radiation source within a generalized source model. This work aims to develop a generalized three-component source model (target, primary collimator, flattening filter) for 6- and 18-MV photon beams that match full phase-space data (PSD). Subsource by subsource comparison of dose distributions, using either source PSD or the source model as input, allows accurate source characterization and has the potential to ease the commissioning procedure, since it is possible to obtain information about which subsource needs to be tuned. This source model is unique in that, compared to previous source models, it retains additional correlations among PS variables, which improves accuracy at nonstandard source-to-surface distances (SSDs). In our study, three-dimensional (3D) dose calculations were performed for SSDs ranging from 50 to 200 cm and for field sizes from 1x1 to 30x30 cm2 as well as a 10x10 cm2 field 5 cm off axis in each direction. The 3D dose distributions, using either full PSD or the source model as input, were compared in terms of dose-difference and distance-to-agreement. With this model, over 99% of the voxels agreed within ±1% or 1 mm for the target, within 2% or 2 mm for the primary collimator, and within ±2.5% or 2 mm for the flattening filter in all cases studied. For the dose distributions, 99% of the dose voxels agreed within 1% or 1 mm when the combined source model--including a charged particle source and the full PSD as input--was used. The accurate and general characterization of each photon source and knowledge of the subsource dose distributions should facilitate source model commissioning procedures by allowing scaling the histogram distributions representing the subsources to be tuned

  12. Definition of stereotactic body radiotherapy. Principles and practice for the treatment of stage I non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Guckenberger, M.; Sauer, O. [University of Wuerzburg, Department of Radiation Oncology, Wuerzburg (Germany); Andratschke, N. [University of Rostock, Department of Radiotherapy and Radiation Oncology, Rostock (Germany); Alheit, H. [Distler Radiation Oncology, Bautzen/Pirna (Germany); Holy, R. [RWTH Aachen University, Department of Radiation Oncology, Aachen (Germany); Moustakis, C. [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Nestle, U. [University of Freiburg, Department of Radiation Oncology, Freiburg (Germany)

    2014-01-15

    This report from the Stereotactic Radiotherapy Working Group of the German Society of Radiation Oncology (Deutschen Gesellschaft fuer Radioonkologie, DEGRO) provides a definition of stereotactic body radiotherapy (SBRT) that agrees with that of other international societies. SBRT is defined as a method of external beam radiotherapy (EBRT) that accurately delivers a high irradiation dose to an extracranial target in one or few treatment fractions. Detailed recommendations concerning the principles and practice of SBRT for early stage non-small cell lung cancer (NSCLC) are given. These cover the entire treatment process; from patient selection, staging, treatment planning and delivery to follow-up. SBRT was identified as the method of choice when compared to best supportive care (BSC), conventionally fractionated radiotherapy and radiofrequency ablation. Based on current evidence, SBRT appears to be on a par with sublobar resection and is an effective treatment option in operable patients who refuse lobectomy. (orig.) [German] Die Arbeitsgruppe ''Stereotaktische Radiotherapie'' der Deutschen Gesellschaft fuer Radioonkologie (DEGRO) erarbeitete eine Definition der Koerperstereotaxie (SBRT), die sich an vorhandene internationale Definitionen anlehnt: Die SBRT ist eine Form der perkutanen Strahlentherapie, die mit hoher Praezision eine hohe Bestrahlungsdosis in einer oder wenigen Bestrahlungsfraktionen in einem extrakraniellen Zielvolumen appliziert. Zur Praxis der SBRT beim nichtkleinzelligen Bronchialkarzinom (NSCLC) im fruehen Stadium werden detaillierte Empfehlungen gegeben, die den gesamten Ablauf der Behandlung von der Indikationsstellung, Staging, Behandlungsplanung und Applikation sowie Nachsorge umfassen. Die Koerperstereotaxie wurde als Methode der Wahl im Vergleich zu Best Supportive Care, zur konventionell fraktionierten Strahlentherapie sowie zur Radiofrequenzablation identifiziert. Die Ergebnisse nach SBRT und sublobaerer Resektion

  13. Dosimetric comparison of a 6-MV flattening-filter and a flattening-filter-free beam for lung stereotactic ablative radiotherapy treatment

    Science.gov (United States)

    Kim, Yon-Lae; Chung, Jin-Beom; Kim, Jae-Sung; Lee, Jeong-Woo; Kim, Jin-Young; Kang, Sang-Won; Suh, Tae-Suk

    2015-11-01

    The purpose of this study was to test the feasibility of clinical usage of a flattening-filter-free (FFF) beam for treatment with lung stereotactic ablative radiotherapy (SABR). Ten patients were treated with SABR and a 6-MV FFF beam for this study. All plans using volumetric modulated arc therapy (VMAT) were optimized in the Eclipse treatment planning system (TPS) by using the Acuros XB (AXB) dose calculation algorithm and were delivered by using a Varian TrueBeam ™ linear accelerator equipped with a high-definition (HD) multi-leaf collimator. The prescription dose used was 48 Gy in 4 fractions. In order to compare the plan using a conventional 6-MV flattening-filter (FF) beam, the SABR plan was recalculated under the condition of the same beam settings used in the plan employing the 6-MV FFF beam. All dose distributions were calculated by using Acuros XB (AXB, version 11) and a 2.5-mm isotropic dose grid. The cumulative dosevolume histograms (DVH) for the planning target volume (PTV) and all organs at risk (OARs) were analyzed. Technical parameters, such as total monitor units (MUs) and the delivery time, were also recorded and assessed. All plans for target volumes met the planning objectives for the PTV ( i.e., V95% > 95%) and the maximum dose ( i.e., Dmax marked reduction (52.97%) in the treatment delivery time. The SABR plan with a FFF beam required a larger number of MUs than the plan with the FF beam, and the mean difference in MUs was 4.65%. This study demonstrated that the use of the FFF beam for lung SABR plan provided better treatment efficiency relative to 6-MV FF beam. This strategy should be particularly beneficial for high dose conformity to the lung and decreased intra-fraction movements because of the shorter treatment delivery time. Future studies are necessary to assess the clinical outcome and the toxicity.

  14. A dual cone-beam CT system for image guided radiotherapy: Initial performance characterization

    Energy Technology Data Exchange (ETDEWEB)

    Li Hao; Bowsher, James; Yin Fangfang [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Giles, William [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2013-02-15

    Purpose: The purpose of this study is to evaluate the performance of a recently developed benchtop dual cone-beam computed tomography (CBCT) system with two orthogonally placed tube/detector sets. Methods: The benchtop dual CBCT system consists of two orthogonally placed 40 Multiplication-Sign 30 cm flat-panel detectors and two conventional x-ray tubes with two individual high-voltage generators sharing the same rotational axis. The x-ray source to detector distance is 150 cm and x-ray source to rotational axis distance is 100 cm for both subsystems. The objects are scanned through 200 Degree-Sign of rotation. The dual CBCT system utilized 110 Degree-Sign of projection data from one detector and 90 Degree-Sign from the other while the two individual single CBCTs utilized 200 Degree-Sign data from each detector. The system performance was characterized in terms of uniformity, contrast, spatial resolution, noise power spectrum, and CT number linearity. The uniformities, within the axial slice and along the longitudinal direction, and noise power spectrum were assessed by scanning a water bucket; the contrast and CT number linearity were measured using the Catphan phantom; and the spatial resolution was evaluated using a tungsten wire phantom. A skull phantom and a ham were also scanned to provide qualitative evaluation of high- and low-contrast resolution. Each measurement was compared between dual and single CBCT systems. Results: Compared to single CBCT, the dual CBCT presented: (1) a decrease in uniformity by 1.9% in axial view and 1.1% in the longitudinal view, as averaged for four energies (80, 100, 125, and 150 kVp); (2) comparable or slightly better contrast (0{approx}25 HU) for low-contrast objects and comparable contrast for high-contrast objects; (3) comparable spatial resolution; (4) comparable CT number linearity with R{sup 2}{>=} 0.99 for all four tested energies; (5) lower noise power spectrum in magnitude. Dual CBCT images of the skull phantom and the

  15. Salvage high-intensity focused ultrasound for the recurrent prostate cancer after radiotherapy in Japan

    Science.gov (United States)

    Shoji, S.; Nakano, M.; Nagata, Y.; Uchida, T.

    2012-10-01

    Aim: to investigate the use of minimally invasive high-intensity focused ultrasound (HIFU) as a salvage therapy in men with localized prostate cancer recurrence following external beam radiotherapy (EBRT), brachytherapy or proton therapy. A review of 22 cases treated using the Sonablate® 500 HIFU device, between August 28, 2002 and April 1, 2010, was carried out. All men had presumed organ-confined, histologically confirmed recurrent prostate adenocarcinoma following radiation therapy. The mean (range) age was 65 (52-80) years with a mean PSA level before radiation therapy of 14.3 (5.7-118) ng/mL. The mean (range) period after radiation therapy to HIFU was 36 (4-96) months. All men with presumed, organ-confined, recurrent disease following EBRT in 14 patients, brachytherapy in 5 patients (4 patients with high-dose brachytherapy with In192 and 1 with low-dose brachytherapy with Au98) or proton therapy in 3 patients treated with salvage HIFU were included. The patients were followed for a mean (range) of 24 months. Biochemical disease-free survival (bDFS) rates in patients with low-, intermediate-and high risk groups were 100%, 86%, and 14%, respectively. All nine patients who received a post HIFU prostate biopsy showed no malignancy. Side-effects included urethral stricture in 4 of the 25 patients (16%) and urinary incontinence in 4 of the 25 patients (16%). Recto-urethral fistula occurred in one patient (4%). Salvage HIFU is a minimally invasive for patients with low-and intermediate risk group with comparable morbidity to other forms of salvage treatment.

  16. Redefining High-Risk Prostate Cancer Based on Distant Metastases and Mortality After High-Dose Radiotherapy With Androgen Deprivation Therapy

    International Nuclear Information System (INIS)

    Purpose: Modern outcomes of high-dose external beam radiotherapy (EBRT) with androgen deprivation therapy (ADT) for high-risk (HR) prostate cancer are not well described. Methods and Materials: We identified 585 patients who met HR criteria by 2010 National Comprehensive Cancer Network guidelines, who were treated with EBRT consisting of ≥74 Gy from 1996 to 2008 at Cleveland Clinic, of whom 95% received ADT. We analyzed biochemical relapse-free survival (bRFS), distant metastases-free survival (DMFS), and prostate cancer-specific mortality (PCSM). Results: The median EBRT dose was 78 Gy, and median ADT duration was 6 months. At 10 years, the bRFS was 50.2%, the DMFS was 71.6%, and the PCSM was 14.4%. On multivariate analysis, significant predictors of bRFS were biopsy Gleason score (bGS) of 8 to 10, stage T3, and prostate-specific antigen (PSA) concentration; predictors of DMFS were bGS of 8 to 10 and stage T3; the only predictor of PCSM was bGS of 8 to 10. The duration of ADT was not predictive of any endpoint. We identified an unfavorable high-risk (UHR) group of stage T1-T2 tumors consisting of bGS of 8 with PSA of >10 ng/ml or bGS of 9 to 10 with any PSA level; the remaining clinically localized cancers comprised the favorable high-risk (FHR) group. Comparing FHR, UHR, and stage T3 groups, the DMFS rates were 81.4%, 57.8%, and 59.1% (p < 0.0001), and the PCSM rates were 7.5%, 28.4%, and 20.6% at 10 years, respectively (p = 0.006). Conclusion: A bGS of 8 to 10 is the strongest predictor of bRFS, DMFS, and PCSM after high-dose EBRT with ADT. The duration of ADT did not correlate with outcome. Future studies should account for the heterogeneity in HR prostate cancer.

  17. SU-E-T-206: Improving Radiotherapy Toxicity Based On Artificial Neural Network (ANN) for Head and Neck Cancer Patients

    International Nuclear Information System (INIS)

    Purpose/Objective(s): The aim of this study is to build the estimator of toxicity using artificial neural network (ANN) for head and neck cancer patients Materials/Methods: An ANN can combine variables into a predictive model during training and considered all possible correlations of variables. We constructed an ANN based on the data from 73 patients with advanced H and N cancer treated with external beam radiotherapy and/or chemotherapy at our institution. For the toxicity estimator we defined input data including age, sex, site, stage, pathology, status of chemo, technique of external beam radiation therapy (EBRT), length of treatment, dose of EBRT, status of post operation, length of follow-up, the status of local recurrences and distant metastasis. These data were digitized based on the significance and fed to the ANN as input nodes. We used 20 hidden nodes (for the 13 input nodes) to take care of the correlations of input nodes. For training ANN, we divided data into three subsets such as training set, validation set and test set. Finally, we built the estimator for the toxicity from ANN output. Results: We used 13 input variables including the status of local recurrences and distant metastasis and 20 hidden nodes for correlations. 59 patients for training set, 7 patients for validation set and 7 patients for test set and fed the inputs to Matlab neural network fitting tool. We trained the data within 15% of errors of outcome. In the end we have the toxicity estimation with 74% of accuracy. Conclusion: We proved in principle that ANN can be a very useful tool for predicting the RT outcomes for high risk H and N patients. Currently we are improving the results using cross validation

  18. Percentage of Cancer Volume in Biopsy Cores Is Prognostic for Prostate Cancer Death and Overall Survival in Patients Treated With Dose-Escalated External Beam Radiotherapy

    International Nuclear Information System (INIS)

    Purpose: To investigate the prognostic utility of the percentage of cancer volume (PCV) in needle biopsy specimens for prostate cancer patients treated with dose-escalated external beam radiotherapy. Methods and Materials: The outcomes were analyzed for 599 men treated for localized prostate cancer with external beam radiotherapy to a minimal planning target volume dose of 75 Gy (range, 75–79.2). We assessed the effect of PCV and the pretreatment and treatment-related factors on the freedom from biochemical failure, freedom from metastasis, cause-specific survival, and overall survival. Results: The median number of biopsy cores was 7 (interquartile range, 6–12), median PCV was 10% (interquartile range, 2.5–25%), and median follow-up was 62 months. The PCV correlated with the National Comprehensive Cancer Network risk group and individual risk features, including T stage, prostate-specific antigen level, Gleason score, and percentage of positive biopsy cores. On log–rank analysis, the PCV stratified by quartile was prognostic for all endpoints, including overall survival. In addition, the PCV was a stronger prognostic factor than the percentage of positive biopsy cores when the two metrics were analyzed together. On multivariate analysis, the PCV predicted a worse outcome for all endpoints, including freedom from biochemical failure, (hazard ratio, 1.9; p = .0035), freedom from metastasis (hazard ratio, 1.7, p = .09), cause-specific survival (hazard ratio, 3.9, p = .014), and overall survival (hazard ratio, 1.8, p = .02). Conclusions: For patients treated with dose-escalated external beam radiotherapy, the volume of cancer in the biopsy specimen adds prognostic value for clinically relevant endpoints, particularly in intermediate- and high-risk patients. Although the PCV determination is more arduous than the percentage of positive biopsy cores, it provides superior risk stratification.

  19. Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, Uros; Herk, Marcel van; Ploeger, Lennert S.; Sonke, Jan-Jakob, E-mail: j.sonke@nki.nl [Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam 1066 CX (Netherlands)

    2014-06-15

    Purpose: Medical linear accelerator mounted cone beam CT (CBCT) scanner provides useful soft tissue contrast for purposes of image guidance in radiotherapy. The presence of extensive scattered radiation has a negative effect on soft tissue visibility and uniformity of CBCT scans. Antiscatter grids (ASG) are used in the field of diagnostic radiography to mitigate the scatter. They usually do increase the contrast of the scan, but simultaneously increase the noise. Therefore, and considering other scatter mitigation mechanisms present in a CBCT scanner, the applicability of ASGs with aluminum interspacing for a wide range of imaging conditions has been inconclusive in previous studies. In recent years, grids using fiber interspacers have appeared, providing grids with higher scatter rejection while maintaining reasonable transmission of primary radiation. The purpose of this study was to evaluate the impact of one such grid on CBCT image quality. Methods: The grid used (Philips Medical Systems) had ratio of 21:1, frequency 36 lp/cm, and nominal selectivity of 11.9. It was mounted on the kV flat panel detector of an Elekta Synergy linear accelerator and tested in a phantom and a clinical study. Due to the flex of the linac and presence of gridline artifacts an angle dependent gain correction algorithm was devised to mitigate resulting artifacts. Scan reconstruction was performed using XVI4.5 augmented with inhouse developed image lag correction and Hounsfield unit calibration. To determine the necessary parameters for Hounsfield unit calibration and software scatter correction parameters, the Catphan 600 (The Phantom Laboratory) phantom was used. Image quality parameters were evaluated using CIRS CBCT Image Quality and Electron Density Phantom (CIRS) in two different geometries: one modeling head and neck and other pelvic region. Phantoms were acquired with and without the grid and reconstructed with and without software correction which was adapted for the different

  20. A framework for inverse planning of beam-on times for 3D small animal radiotherapy using interactive multi-objective optimisation

    International Nuclear Information System (INIS)

    Advances in precision small animal radiotherapy hardware enable the delivery of increasingly complicated dose distributions on the millimeter scale. Manual creation and evaluation of treatment plans becomes difficult or even infeasible with an increasing number of degrees of freedom for dose delivery and available image data. The goal of this work is to develop an optimisation model that determines beam-on times for a given beam configuration, and to assess the feasibility and benefits of an automated treatment planning system for small animal radiotherapy.The developed model determines a Pareto optimal solution using operator-defined weights for a multiple-objective treatment planning problem. An interactive approach allows the planner to navigate towards, and to select the Pareto optimal treatment plan that yields the most preferred trade-off of the conflicting objectives. This model was evaluated using four small animal cases based on cone-beam computed tomography images. Resulting treatment plan quality was compared to the quality of manually optimised treatment plans using dose-volume histograms and metrics.Results show that the developed framework is well capable of optimising beam-on times for 3D dose distributions and offers several advantages over manual treatment plan optimisation. For all cases but the simple flank tumour case, a similar amount of time was needed for manual and automated beam-on time optimisation. In this time frame, manual optimisation generates a single treatment plan, while the inverse planning system yields a set of Pareto optimal solutions which provides quantitative insight on the sensitivity of conflicting objectives. Treatment planning automation decreases the dependence on operator experience and allows for the use of class solutions for similar treatment scenarios. This can shorten the time required for treatment planning and therefore increase animal throughput. In addition, this can improve treatment standardisation and

  1. Long-term outcome and toxicity of hypofractionated stereotactic body radiotherapy as a boost treatment for head and neck cancer: the importance of boost volume assessment

    Directory of Open Access Journals (Sweden)

    Lee Dong

    2012-06-01

    Full Text Available Abstract Background The aim of this study was to report the long-term clinical outcomes of patients who received stereotactic body radiotherapy (SBRT as a boost treatment for head and neck cancer. Materials and methods Between March 2004 and July 2007, 26 patients with locally advanced, medically inoperable head and neck cancer or gross residual tumors in close proximity to critical structures following head and neck surgery were treated with SBRT as a boost treatment. All patients were initially treated with standard external beam radiotherapy (EBRT. SBRT boost was prescribed to the median 80% isodose line with a median dose of 21 (range 10–25 Gy in 2–5 (median, 5 fractions. Results The median follow-up after SBRT was 56 (range 27.6 − 80.2 months. The distribution of treatment sites in 26 patients was as follows: the nasopharynx, including the base of the skull in 10 (38.5%; nasal cavity or paranasal sinus in 8 (30.8%; periorbit in 4 (15.4%; tongue in 3 (11.5%; and oropharyngeal wall in 1 (3.8%. The median EBRT dose before SBRT was 50.4 Gy (range 39.6 − 70.2. The major response rate was 100% with 21 (80.8% complete responses (CR. Severe (grade ≥ 3 late toxicities developed in 9 (34.6% patients, and SBRT boost volume was a significant parameter predicting severe late complication. Conclusions The present study demonstrates that a modern SBRT boost is a highly efficient tool for local tumor control. However, we observed a high frequency of serious late complications. More optimized dose fractionation schedule and patient selection are required to achieve excellent local control without significant late morbidities in head and neck boost treatment.

  2. COMPARATIVE STUDY OF WEEKLY VERSUS THREE WEEKLY CISPLATIN IN ADVANCED CASES OF CARCINOMA CERVIX ALONG WITH RADIOTHERAPY

    Directory of Open Access Journals (Sweden)

    Preety

    2015-10-01

    Full Text Available : OBJECTIVE: To determine the clinical response and compliance of patients with external radiation therapy with concomitant weekly inj. CISPLATIN (30mg/m2 versus external radiation therapy with three weekly inj.CISPLATIN (100mg/m2. MATERIALS & METHODS: This prospective study was conducted in the Department of Radiation oncology, GOVT. CANCER HOSPITAL. M.G.M. MEDICAL COLLEGE INDORE (M. P. A total of 50 patients were enrolled in study from April 2013 to October 2013 after obtaining written and informed consent. The patients were randomized into two arms. Arm 1- Concurrent weekly cisplatin with Radiotherapy. Arm 2 - Concurrent 3 Weekly Cisplatin with Radiotherapy. All the patients received external beam radiotherapy (EBRT along with 2-3 sittings of intracavitary radiotherapy (ICR with concurrent weekly/ 3 weekly cisplatin. All the patients were simulated in supine position with proper immobilisation. Pelvic EBRT was given using COBALT 60 THERATRON 780C by two parallel opposed AP-PA portals or by four field techniques. A mid plane dose of 46 Gy 20#. RESULTS: out of 25 patients, 19 patients from Arm A and 21 from Arm B had a complete response to treatment, whereas partial and progressive diseases responses were not observed in either of the patients of Arm A and Arm B. On the other hand 12 to 8 percent patients had a stable disease. However, from the whole lot, only 2(8% patients of Arm B had a recurrence of the diseases. Statistically the responses to the different treatment plans on the patients in Arm A and Arm B did not differ significantly from each other. CONCLUSION: this study showed that tri-weekly cispiatin 100mg/m2 concurrent with radiation is feasible and more effective than the conventional weekly cispiatin 40mg/m2- based regimen in achieving local control of the disease at 1 month follow up, however this difference was not sustained over prolonged follow-up. Longer follow-up is required to assess the delayed toxicity, overall survival

  3. Personalized Assessment of kV Cone Beam Computed Tomography Doses in Image-guided Radiotherapy of Pediatric Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yibao [Beijing Key Lab of Medical Physics and Engineering, Peking University, Beijing (China); Yan Yulong [Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Nath, Ravinder [Department of Therapeutic Radiology, Yale University, New Haven, Connecticut (United States); Bao Shanglian [Beijing Key Lab of Medical Physics and Engineering, Peking University, Beijing (China); Deng Jun, E-mail: jun.deng@yale.edu [Department of Therapeutic Radiology, Yale University, New Haven, Connecticut (United States)

    2012-08-01

    Purpose: To develop a quantitative method for the estimation of kV cone beam computed tomography (kVCBCT) doses in pediatric patients undergoing image-guided radiotherapy. Methods and Materials: Forty-two children were retrospectively analyzed in subgroups of different scanned regions: one group in the head-and-neck and the other group in the pelvis. Critical structures in planning CT images were delineated on an Eclipse treatment planning system before being converted into CT phantoms for Monte Carlo simulations. A benchmarked EGS4 Monte Carlo code was used to calculate three-dimensional dose distributions of kVCBCT scans with full-fan high-quality head or half-fan pelvis protocols predefined by the manufacturer. Based on planning CT images and structures exported in DICOM RT format, occipital-frontal circumferences (OFC) were calculated for head-and-neck patients using DICOMan software. Similarly, hip circumferences (HIP) were acquired for the pelvic group. Correlations between mean organ doses and age, weight, OFC, and HIP values were analyzed with SigmaPlot software suite, where regression performances were analyzed with relative dose differences (RDD) and coefficients of determination (R{sup 2}). Results: kVCBCT-contributed mean doses to all critical structures decreased monotonically with studied parameters, with a steeper decrease in the pelvis than in the head. Empirical functions have been developed for a dose estimation of the major organs at risk in the head and pelvis, respectively. If evaluated with physical parameters other than age, a mean RDD of up to 7.9% was observed for all the structures in our population of 42 patients. Conclusions: kVCBCT doses are highly correlated with patient size. According to this study, weight can be used as a primary index for dose assessment in both head and pelvis scans, while OFC and HIP may serve as secondary indices for dose estimation in corresponding regions. With the proposed empirical functions, it is possible

  4. Multivariate normal tissue complication probability modeling of gastrointestinal toxicity after external beam radiotherapy for localized prostate cancer

    International Nuclear Information System (INIS)

    The risk of radio-induced gastrointestinal (GI) complications is affected by several factors other than the dose to the rectum such as patient characteristics, hormonal or antihypertensive therapy, and acute rectal toxicity. Purpose of this work is to study clinical and dosimetric parameters impacting on late GI toxicity after prostate external beam radiotherapy (RT) and to establish multivariate normal tissue complication probability (NTCP) model for radiation-induced GI complications. A total of 57 men who had undergone definitive RT for prostate cancer were evaluated for GI events classified using the RTOG/EORTC scoring system. Their median age was 73 years (range 53–85). The patients were assessed for GI toxicity before, during, and periodically after RT completion. Several clinical variables along with rectum dose-volume parameters (Vx) were collected and their correlation to GI toxicity was analyzed by Spearman’s rank correlation coefficient (Rs). Multivariate logistic regression method using resampling techniques was applied to select model order and parameters for NTCP modeling. Model performance was evaluated through the area under the receiver operating characteristic curve (AUC). At a median follow-up of 30 months, 37% (21/57) patients developed G1-2 acute GI events while 33% (19/57) were diagnosed with G1-2 late GI events. An NTCP model for late mild/moderate GI toxicity based on three variables including V65 (OR = 1.03), antihypertensive and/or anticoagulant (AH/AC) drugs (OR = 0.24), and acute GI toxicity (OR = 4.3) was selected as the most predictive model (Rs = 0.47, p < 0.001; AUC = 0.79). This three-variable model outperforms the logistic model based on V65 only (Rs = 0.28, p < 0.001; AUC = 0.69). We propose a logistic NTCP model for late GI toxicity considering not only rectal irradiation dose but also clinical patient-specific factors. Accordingly, the risk of G1-2 late GI increases as V65 increases, it is higher for patients experiencing

  5. Deformable image registration for contour propagation from CT to cone-beam CT scans in radiotherapy of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Thor, Maria; Muren, Ludvig Paul (Clinical Inst., Aarhus Univ., Aarhus (Denmark); Dept. of Medical Physics, Aarhus Univ. Hospital, Aarhus (Denmark); Dept. of Oncology, Aarhus Univ. Hospital, Aarhus (Denmark)), e-mail: mariator@rm.dk; Petersen, Joergen B. B. (Dept. of Medical Physics, Aarhus Univ. Hospital, Aarhus (Denmark)); Bentzen, Lise; Hoeyer, Morten (Dept. of Oncology, Aarhus Univ. Hospital, Aarhus (Denmark))

    2011-08-15

    Background and purpose. Daily organ motion occurring during the course of radiotherapy in the pelvic region leads to uncertainties in the doses delivered to the tumour and the organs at risk. Motion patterns include both volume and shape changes, calling for deformable image registration (DIR), in approaches involving dose accumulation and adaptation. In this study, we tested the performance of a DIR application for contour propagation from the treatment planning computed tomography (pCT) to repeat cone-beam CTs (CBCTs) for a set of prostate cancer patients. Material and methods. The prostate, rectum and bladder were delineated in the pCT and in six to eight repeat CBCTs for each of five patients. The pCT contours were propagated onto the corresponding CBCT using the Multi-modality Image Registration and Segmentation application, resulting in 36 registrations. Prior to the DIR, a rigid registration was performed. The algorithm used for the DIR was based on a 'demons' algorithm and the performance of it was examined quantitatively using the Dice similarity coefficient (DSC) and qualitatively as visual slice-by-slice scoring by a radiation oncologist grading the deviations in shape and/or distance relative to the anatomy. Results. The average DSC (range) for the DIR over all scans and patients was 0.80 (0.65-0.87) for prostate, 0.77 (0.63-0.87) for rectum and 0.73 (0.34-0.91) for bladder, while the corresponding DSCs for the rigid registrations were 0.77 (0.65-0.86), 0.71 (0.55-0.82) and 0.64 (0.33-0.87). The percentage of propagated contours of good/acceptable quality was 45% for prostate; 20% for rectum and 33% for bladder. For the bladder, there was an association between the average DSC and the different scores of the qualitative evaluation. Conclusions. DIR improved the performance of pelvic organ contour propagation from the pCT to CBCTs as compared to rigid registration only. Still, a large fraction of the propagated rectum and bladder contours were

  6. SU-E-T-591: Optimizing the Flattening Filter Free Beam Selection in RapidArc-Based Stereotactic Body Radiotherapy for Stage I Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B-T; Lu, J-Y [Cancer Hospital of Shantou University Medical College, Shantou (China)

    2015-06-15

    Purpose: To optimize the flattening filter free (FFF) beam energy selection in stereotactic body radiotherapy (SBRT) treatment for stage I lung cancer with different fraction schemes. Methods: Twelve patients suffering from stage I lung cancer were enrolled in this study. Plans were designed using 6XFFF and 10XFFF beams with the most widely used fraction schemes of 4*12 Gy, 3*18 Gy and 1*34 Gy, respectively. The plan quality was appraised in terms of planning target volume (PTV) coverage, conformity of the prescribed dose (CI100%), intermediate dose spillage (R50% and D2cm), organs at risk (OARs) sparing and beam-on time. Results: The 10XFFF beam predicted 1% higher maximum, mean dose to the PTV and 4–5% higher R50% compared with the 6XFFF beam in the three fraction schemes, whereas the CI100% and D2cm was similar. Most importantly, the 6XFFF beam exhibited 3–10% lower dose to all the OARs. However, the 10XFFF beam reduced the beam-on time by 31.9±7.2%, 38.7±2.8% and 43.6±4.0% compared with the 6XFFF beam in the 4*12 Gy, 3*18 Gy and 1*34 Gy schemes, respectively. Beam-on time was 2.2±0.2 vs 1.5±0.1, 3.3±0.9 vs 2.0±0.5 and 6.3±0.9 vs 3.5±0.4 minutes for the 6XFFF and 10XFFF one in the three fraction schemes. Conclusion: The 6XFFF beam obtains better OARs sparing in SBRT treatment for stage I lung cancer, but the 10XFFF one provides improved treatment efficiency. To balance the OARs sparing and intrafractional variation as a function of prolonged treatment time, the authors recommend to use the 6XFFF beam in the 4*12 Gy and 3*18 Gy schemes for better OARs sparing. However, for the 1*34 Gy scheme, the 10XFFF beam is recommended to achieve improved treatment efficiency.

  7. SU-E-T-591: Optimizing the Flattening Filter Free Beam Selection in RapidArc-Based Stereotactic Body Radiotherapy for Stage I Lung Cancer

    International Nuclear Information System (INIS)

    Purpose: To optimize the flattening filter free (FFF) beam energy selection in stereotactic body radiotherapy (SBRT) treatment for stage I lung cancer with different fraction schemes. Methods: Twelve patients suffering from stage I lung cancer were enrolled in this study. Plans were designed using 6XFFF and 10XFFF beams with the most widely used fraction schemes of 4*12 Gy, 3*18 Gy and 1*34 Gy, respectively. The plan quality was appraised in terms of planning target volume (PTV) coverage, conformity of the prescribed dose (CI100%), intermediate dose spillage (R50% and D2cm), organs at risk (OARs) sparing and beam-on time. Results: The 10XFFF beam predicted 1% higher maximum, mean dose to the PTV and 4–5% higher R50% compared with the 6XFFF beam in the three fraction schemes, whereas the CI100% and D2cm was similar. Most importantly, the 6XFFF beam exhibited 3–10% lower dose to all the OARs. However, the 10XFFF beam reduced the beam-on time by 31.9±7.2%, 38.7±2.8% and 43.6±4.0% compared with the 6XFFF beam in the 4*12 Gy, 3*18 Gy and 1*34 Gy schemes, respectively. Beam-on time was 2.2±0.2 vs 1.5±0.1, 3.3±0.9 vs 2.0±0.5 and 6.3±0.9 vs 3.5±0.4 minutes for the 6XFFF and 10XFFF one in the three fraction schemes. Conclusion: The 6XFFF beam obtains better OARs sparing in SBRT treatment for stage I lung cancer, but the 10XFFF one provides improved treatment efficiency. To balance the OARs sparing and intrafractional variation as a function of prolonged treatment time, the authors recommend to use the 6XFFF beam in the 4*12 Gy and 3*18 Gy schemes for better OARs sparing. However, for the 1*34 Gy scheme, the 10XFFF beam is recommended to achieve improved treatment efficiency

  8. Establishment of dosimetric references for high energy X-ray beams of very small field sizes (≤ 1 cm2) used in radiotherapy

    International Nuclear Information System (INIS)

    The French primary standard dosimetry laboratory 'Laboratoire National Henri Becquerel' is in charge of the establishment of dosimetric standards for ionizing radiation beams. Absolute dose measurements are thus available for X-Ray beams used in radiotherapy for field sizes between 10 and 2 cm. Since the miniaturization of absolute dosimeters is not possible for smaller field sizes, a dose area product (DAP) has been suggested as a substitute to the absorbed dose at a point.In order to measure a DAP with dosimeters which sensitive surface is larger than the beam, a graphite calorimeter with a sensitive surface of 3 cm diameter was designed, built and tested. An ionization chamber with the same diameter was realized and tested to transfer the dosimetric references to the end users. Its calibration factor in terms of DAP was determined in circular beams of 2, 1 and 0.75 cm diameter with an uncertainty smaller than 0.7 %. The two-Dimension relative dose distribution was measured thanks to a diamond dosimeter, a PinPoint ionization chamber and gafchromic films, using a specific protocol. Both approaches, respectively based on a PDS and an absorbed dose to water at a point, were in good agreement in the 2 cm beam. Correction factors determined from Monte Carlo simulations and measured dose distributions were needed for this comparison. The calibration factor of the large ionization chamber in the 1 and 0.75 cm diameter beams were in good agreement within the uncertainties but a gap of -2.6 % was found with the one established in the 2 cm diameter beam. As a result, the DAP can be used if the sensitive surface is much larger than the beam section. (author)

  9. A comparative dosimetric study on tangential photon beams, intensity-modulated radiation therapy (IMRT) and modulated electron radiotherapy (MERT) for breast cancer treatment

    Science.gov (United States)

    Ma, C.-M.; Ding, M.; Li, J. S.; Lee, M. C.; Pawlicki, T.; Deng, J.

    2003-04-01

    Recently, energy- and intensity-modulated electron radiotherapy (MERT) has garnered a growing interest for the treatment of superficial targets. In this work, we carried out a comparative dosimetry study to evaluate MERT, photon beam intensity-modulated radiation therapy (IMRT) and conventional tangential photon beams for the treatment of breast cancer. A Monte Carlo based treatment planning system has been investigated, which consists of a set of software tools to perform accurate dose calculation, treatment optimization, leaf sequencing and plan analysis. We have compared breast treatment plans generated using this home-grown treatment optimization and dose calculation software for these treatment techniques. The MERT plans were planned with up to two gantry angles and four nominal energies (6, 9, 12 and 16 MeV). The tangential photon treatment plans were planned with 6 MV wedged photon beams. The IMRT plans were planned using both multiple-gantry 6 MV photon beams or two 6 MV tangential beams. Our results show that tangential IMRT can reduce the dose to the lung, heart and contralateral breast compared to conventional tangential wedged beams (up to 50% reduction in high dose volume or 5 Gy in the maximum dose). MERT can reduce the maximum dose to the lung by up to 20 Gy and to the heart by up to 35 Gy compared to conventional tangential wedged beams. Multiple beam angle IMRT can significantly reduce the maximum dose to the lung and heart (up to 20 Gy) but it induces low and medium doses to a large volume of normal tissues including lung, heart and contralateral breast. It is concluded that MERT has superior capabilities to achieve dose conformity both laterally and in the depth direction, which will be well suited for treating superficial targets such as breast cancer.

  10. Cone-beam CT-guided radiotherapy in the management of lung cancer. Diagnostic and therapeutic value

    Energy Technology Data Exchange (ETDEWEB)

    Elsayad, Khaled; Kriz, Jan; Reinartz, Gabriele; Scobioala, Sergiu; Ernst, Iris; Haverkamp, Uwe; Eich, Hans Theodor [University Hospital of Muenster, Department of Radiation Oncology, Muenster (Germany)

    2016-02-15

    Recent studies have demonstrated an increase in the necessity of adaptive planning over the course of lung cancer radiation therapy (RT) treatment. In this study, we evaluated intrathoracic changes detected by cone-beam CT (CBCT) in lung cancer patients during RT. A total of 71 lung cancer patients treated with fractionated CBCT-guided RT were evaluated. Intrathoracic changes and plan adaptation priority (AP) scores were compared between small cell lung cancer (SCLC, n = 13) and non-small cell lung cancer (NSCLC, n = 58) patients. The median cumulative radiation dose administered was 54 Gy (range 30-72 Gy) and the median fraction dose was 1.8 Gy (range 1.8-3.0 Gy). All patients were subjected to a CBCT scan at least weekly (range 1-5/week). We observed intrathoracic changes in 83 % of the patients over the course of RT [58 % (41/71) regression, 17 % (12/71) progression, 20 % (14/71) atelectasis, 25 % (18/71) pleural effusion, 13 % (9/71) infiltrative changes, and 10 % (7/71) anatomical shift]. Nearly half, 45 % (32/71), of the patients had one intrathoracic soft tissue change, 22.5 % (16/71) had two, and three or more changes were observed in 15.5 % (11/71) of the patients. Plan modifications were performed in 60 % (43/71) of the patients. Visual volume reduction did correlate with the number of CBCT scans acquired (r = 0.313, p = 0.046) and with the timing of chemotherapy administration (r = 0.385, p = 0.013). Weekly CBCT monitoring provides an adaptation advantage in patients with lung cancer. In this study, the monitoring allowed for plan adaptations due to tumor volume changes and to other anatomical changes. (orig.) [German] Neuere Studien haben eine zunehmende Notwendigkeit der adaptiven Bestrahlungsplanung im Verlauf der Bestrahlungsserie bei Patienten mit Lungenkrebs nachgewiesen. In der vorliegenden Studie haben wir intrathorakale Aenderungen mittels Cone-beam-CT (CBCT) bei Lungenkrebspatienten waehrend der Radiotherapie (RT) analysiert. Analysiert wurden

  11. Proton beams in radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Khoroshkov, V.S.; Minakova, E.I. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)

    1998-11-01

    A branch of radiology, proton therapy employs fast protons as a tool for the treatment of various, mainly oncological, diseases. The features of tissue ionization by protons (Bragg peak) facilitate a further step towards solving the principal challenge in radiology: to deliver a sufficiently high and homogeneous dose to virtually any tumour, while sparing healthy neighbouring tissues, organs and structures. The state of the art of proton therapy is described, as well as the main technical, physics and clinical results gained since the 1950s at high-energy physics centres worldwide. The future of proton therapy is connected with the construction of hospital-based facilities with dedicated medical accelerators and modern technical instrumentation. (author)

  12. Evaluation of the effect of tooth and dental restoration material on electron dose distribution and production of photon contamination in electron beam radiotherapy.

    Science.gov (United States)

    Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Akbari, Fatemeh; Mehrpouyan, Mohammad; Sobhkhiz Sabet, Leila

    2016-03-01

    The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron beams of a Siemens Primus linac. MCNPX Monte Carlo code was utilized and a 10 × 10 cm(2) applicator was simulated in the cases of tooth and combinations of tooth and Ceramco C3 ceramic veneer, tooth and Eclipse alloy and tooth and amalgam restoration materials in a soft tissue phantom. The relative electron and photon contamination doses were calculated for these materials. The presence of tooth and dental restoration material changed the electron dose distribution and photon contamination in phantom, depending on the type of the restoration material and electron beam's energy. The maximum relative electron dose was 1.07 in the presence of tooth including amalgam for 14 MeV electron beam. When 100.00 cGy was prescribed for the reference point, the maximum absolute electron dose was 105.10 cGy in the presence of amalgam for 12 MeV electron beam and the maximum absolute photon contamination dose was 376.67 μGy for tooth in 14 MeV electron beam. The change in electron dose distribution should be considered in treatment planning, when teeth are irradiated in electron beam radiotherapy. If treatment planning can be performed in such a way that the teeth are excluded from primary irradiation, the potential errors in dose delivery to the tumour and normal tissues can be avoided. PMID:26581762

  13. Evaluation of the effect of tooth and dental restoration material on electron dose distribution and production of photon contamination in electron beam radiotherapy.

    Science.gov (United States)

    Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Akbari, Fatemeh; Mehrpouyan, Mohammad; Sobhkhiz Sabet, Leila

    2016-03-01

    The aim of this study is to evaluate the effect of tooth and dental restoration materials on electron dose distribution and photon contamination production in electron beams of a medical linac. This evaluation was performed on 8, 12 and 14 MeV electron beams of a Siemens Primus linac. MCNPX Monte Carlo code was utilized and a 10 × 10 cm(2) applicator was simulated in the cases of tooth and combinations of tooth and Ceramco C3 ceramic veneer, tooth and Eclipse alloy and tooth and amalgam restoration materials in a soft tissue phantom. The relative electron and photon contamination doses were calculated for these materials. The presence of tooth and dental restoration material changed the electron dose distribution and photon contamination in phantom, depending on the type of the restoration material and electron beam's energy. The maximum relative electron dose was 1.07 in the presence of tooth including amalgam for 14 MeV electron beam. When 100.00 cGy was prescribed for the reference point, the maximum absolute electron dose was 105.10 cGy in the presence of amalgam for 12 MeV electron beam and the maximum absolute photon contamination dose was 376.67 μGy for tooth in 14 MeV electron beam. The change in electron dose distribution should be considered in treatment planning, when teeth are irradiated in electron beam radiotherapy. If treatment planning can be performed in such a way that the teeth are excluded from primary irradiation, the potential errors in dose delivery to the tumour and normal tissues can be avoided.

  14. Evaluation of the relative effectiveness of LiF-based TL detectors for electron radiotherapy beams over the energy range 6-20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Nahajowski, D.; Gora, E.; Rozwadowska-Bogusz, B.; Lesiak, J.; Polak, B.; Kabat, D.; Zawadzki, P. [Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow Branch, Garncarska 11, 31-115 Krakow (Poland); Waligorski, M.P.R. [Centre of Oncology, Maria Sklodowska-Curie Memorial Institute, Krakow Branch, Garncarska 11, 31-115 Krakow (Poland); Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), Krakow (Poland)], E-mail: z5waligo@cyf-kr.edu.pl

    2008-02-15

    We have performed systematic measurements of the efficiency, C{sub E}=/, of MTS-N (LiF:Mg,Ti) and LiB (Li{sub 2}B{sub 4}O{sub 7}:Mn,Si) thermoluminescence (TL) detectors exposed to electron radiotherapy beams of nominal energy 6, 9, 12, 16 and 20 MeV relative to Co-60 or 6 MV photon beams ( is the average TL output of a batch of detectors exposed to a given dose of photon beam radiation or to a beam of electrons of energy E). The TL detectors were sintered pellets of 4.5 mm diameter and ca. 0.8 mm thickness. Detectors were exposed in water to 2 Gy at respective energy-dependent depths d{sub max} applied in clinical dosimetry. The obtained results were re-calculated versus mean electron energy in the beam at depths d{sub max}. We found that, for clinical purposes, both types of TL detectors show no energy dependence: presented as average values over the investigated energy range, for MTS-N detectors =1.07{+-}1.1% and for LiB =1.03{+-}1.7%. Thus, while no correction is required for dose values estimated by LiB TLDs, the under-response of MTS-N detectors exposed to a beam of electrons has to be corrected by about 7%. At mean energy of electrons in therapeutic electron beams below about 5 MeV a decline in the response of both types of TL detectors is observed.

  15. Dose calculation of Acuros XB and Anisotropic Analytical Algorithm in lung stereotactic body radiotherapy treatment with flattening filter free beams and the potential role of calculation grid size

    International Nuclear Information System (INIS)

    The study aimed to appraise the dose differences between Acuros XB (AXB) and Anisotropic Analytical Algorithm (AAA) in stereotactic body radiotherapy (SBRT) treatment for lung cancer with flattening filter free (FFF) beams. Additionally, the potential role of the calculation grid size (CGS) on the dose differences between the two algorithms was also investigated. SBRT plans with 6X and 10X FFF beams produced from the CT scan data of 10 patients suffering from stage I lung cancer were enrolled in this study. Clinically acceptable treatment plans with AAA were recalculated using AXB with the same monitor units (MU) and identical multileaf collimator (MLC) settings. Furthermore, different CGS (2.5 mm and 1 mm) in the two algorithms was also employed to investigate their dosimetric impact. Dose to planning target volumes (PTV) and organs at risk (OARs) between the two algorithms were compared. PTV was separated into PTV-soft (density in soft-tissue range) and PTV-lung (density in lung range) for comparison. The dose to PTV-lung predicted by AXB was found to be 1.33 ± 1.12% (6XFFF beam with 2.5 mm CGS), 2.33 ± 1.37% (6XFFF beam with 1 mm CGS), 2.81 ± 2.33% (10XFFF beam with 2.5 mm CGS) and 3.34 ± 1.76% (10XFFF beam with 1 mm CGS) lower compared with that by AAA, respectively. However, the dose directed to PTV-soft was comparable. For OARs, AXB predicted a slightly lower dose to the aorta, chest wall, spinal cord and esophagus, regardless of whether the 6XFFF or 10XFFF beam was utilized. Exceptionally, dose to the ipsilateral lung was significantly higher with AXB. AXB principally predicts lower dose to PTV-lung compared to AAA and the CGS contributes to the relative dose difference between the two algorithms

  16. Geometrical determinations of IMRT photon pencil-beam path in radiotherapy wedges and limit divergence angle with the Anisotropic Analytic Algorithm (AAA

    Directory of Open Access Journals (Sweden)

    Francisco Casesnoves

    2014-08-01

    Full Text Available Purpose: Static wedge filters (WF are commonly used in radiation therapy, forward and/or inverse planning. We calculated the exact 2D/3D geometrical pathway of the photon-beam through the usual alloy WF, in order to get a better dose related to the beam intensity attenuation factor(s, after the beam has passed through the WF. The objective was to provide general formulation into the Anisotropic Analytical Algorithm (AAA model coordinates system (depending on collimator/wedge angles that also can be applied to other models. Additionally, second purpose of this study was to develop integral formulation for 3D wedge exponential factor with statistical approximations, with introduction for the limit angle/conformal wedge.Methods: The radiotherapy model used to develop this mathematical task is the classical superposition-convolution algorithm, AAA (developed by Ulmer and Harder. We worked with optimal geometrical approximations to make the computational IMRT calculations quicker/reduce the planning-system time. Analytic geometry/computational-techniques to carry out simulations (for standard wedges are detailed/developed sharply. Integral developments/integral-statistical approximations are explained. Beam-divergence limit Angle for optimal wedge filtration formulas is calculated/sketched, with geometrical approximations. Fundamental trigonometry is used for this purpose.Results: Extent simulation tables for WF of 15º, 30º, 45º, and 60º are shown with errors. As a result, it is possible to determine the best individual treatment dose distribution for each patient. We presented these basic simulations/numerical examples for standard manufacturing WF of straight sloping surface, to check the accuracy/errors of the calculations. Simulations results give low RMS/Relative Error values (formulated for WF of 15º, 30º, 45º, and 60º.Conclusion: We obtained a series of formulas of analytic geometry for WF that can be applied for any particular dose

  17. Evaluation of the utilization of external radiotherapy in the treatment of localized prostate cancer in Andalusia, Spain

    International Nuclear Information System (INIS)

    Around 27,000 new cases of prostate cancer are diagnosed every year in Spain and 5400 die from this disease. Radiotherapy (RT), alone or combined, has proven to be effective as initial treatment in patients with localized disease. Our objective was to evaluate the use of external beam RT (EBRT) in our region, comparing the indication rate and irradiation rate and examining variability in its application among hospitals. We conducted a review of RT guidelines and indication studies for prostate cancer (% expected irradiation). Data were gathered from all twelve public healthcare centers in Andalusia (Spain) on RT-treated prostate cancer patients during 2013 (% actual irradiation) and from nine of the centers on RT discharge reports. Information was classified according to type of hospital, tumor risk category and RT treatment (technique, dosage, volume, toxicity). The estimated RT rate was 67 % (1289/1917), 43 % were aged > 70 years, 44.7 % had ECOG performance status of 0); 44.7 % had high-risk tumors; 57 % underwent RT associated with hormone therapy; 70 % of patients receiving RT were treated with 3D planning (30 % IGRT); and doses were 70–76 Gy in 70 % of cases and >76 Gy in 10.7 %. Acute gastrointestinal and genitourinary toxicities were < grade 2 in 79 and 89 % of patients, respectively. An irradiation rate significantly below the mean for the study was found in four provinces. There was a significant difference among provinces in the distribution of risk groups. Underutilization of EBRT was estimated to be around 30 % in prostate cancer patients, with an elevated variability in irradiation rates among hospitals related to differences in available technology and in the distribution of patients with different risk levels. These data should be a matter of concern to regional health managers, given the negative and measurable impact on the survival of patients

  18. Evaluation of the dosimetric impact of applying flattening filter-free beams in intensity-modulated radiotherapy for early-stage upper thoracic carcinoma of oesophagus

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wuzhe; Lin, Zhixiong; Yang, Zhining; Fang, Weisheng; Lai, Peibo; Lu, Jiayang [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong (China); Wu, Vincent WC, E-mail: vincent.wu@polyu.edu.hk [Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong (China)

    2015-06-15

    Flattening filter-free (FFF) radiation beams have recently become clinically available on modern linear accelerators in radiation therapy. This study aimed to evaluate the dosimetric impact of using FFF beams in intensity-modulated radiotherapy (IMRT) for early-stage upper thoracic oesophageal cancer. Eleven patients with primary stage upper thoracic oesophageal cancer were recruited. For each patient, two IMRT plans were computed using conventional beams (Con-P) and FFF beams (FFF-P), respectively. Both plans employed a five-beam arrangement and were prescribed with 64 Gy to (planning target volume) PTV1 and 54 Gy to PTV2 in 32 fractions using 6 MV photons. The dose parameters of the target volumes and organs at risks (OARs), and treatment parameters including the monitor units (MU) and treatment time (TT) for Con-P and FFF-P were recorded and compared. The mean D{sub 5} of PTV1 and PTV2 were higher in FFF-P than Con-P by 0.4 Gy and 0.3 Gy, respectively. For the OARs, all the dose parameters did not show significant difference between the two plans except the mean V{sub 5} and V{sub 10} of the lung in which the FFF-P was lower (46.7% vs. 47.3% and 39.1% vs. 39.6%, respectively). FFF-P required 54% more MU but 18.4% less irradiation time when compared to Con-P. The target volume and OARs dose distributions between the two plans were comparable. However, FFF-P was more effective in sparing the lung from low dose and reduced the mean TT compared with Con-P. Long-term clinical studies are suggested to evaluate the radiobiological effects of FFF beams.

  19. Evaluation of the dosimetric impact of applying flattening filter-free beams in intensity-modulated radiotherapy for early-stage upper thoracic carcinoma of oesophagus

    International Nuclear Information System (INIS)

    Flattening filter-free (FFF) radiation beams have recently become clinically available on modern linear accelerators in radiation therapy. This study aimed to evaluate the dosimetric impact of using FFF beams in intensity-modulated radiotherapy (IMRT) for early-stage upper thoracic oesophageal cancer. Eleven patients with primary stage upper thoracic oesophageal cancer were recruited. For each patient, two IMRT plans were computed using conventional beams (Con-P) and FFF beams (FFF-P), respectively. Both plans employed a five-beam arrangement and were prescribed with 64 Gy to (planning target volume) PTV1 and 54 Gy to PTV2 in 32 fractions using 6 MV photons. The dose parameters of the target volumes and organs at risks (OARs), and treatment parameters including the monitor units (MU) and treatment time (TT) for Con-P and FFF-P were recorded and compared. The mean D5 of PTV1 and PTV2 were higher in FFF-P than Con-P by 0.4 Gy and 0.3 Gy, respectively. For the OARs, all the dose parameters did not show significant difference between the two plans except the mean V5 and V10 of the lung in which the FFF-P was lower (46.7% vs. 47.3% and 39.1% vs. 39.6%, respectively). FFF-P required 54% more MU but 18.4% less irradiation time when compared to Con-P. The target volume and OARs dose distributions between the two plans were comparable. However, FFF-P was more effective in sparing the lung from low dose and reduced the mean TT compared with Con-P. Long-term clinical studies are suggested to evaluate the radiobiological effects of FFF beams

  20. Radiotherapy of cutaneous lymphomas; Radiotherapie des lymphomes cutanes

    Energy Technology Data Exchange (ETDEWEB)

    Kirova, Y.M.; Piedbois, Y.; Pan, Q.; Guo, J.P.; Le Bourgeois, J.P. [Hopital Henri-Mondor, 94 - Creteil (France). Dept. de cancerologie

    1999-03-01

    Radiotherapy plays an important role in the treatment of cutaneous lymphomas. In the treatment of Mycosis fungoides, total skin electron beam radiation therapy is efficient for patients with limited and superficial forms of the disease. Radiotherapy is also efficient for the locally advanced forms of non-epidermo-tropic lymphomas. The palliative radiotherapy is indicated for advanced, nodular and treatment resistant forms of cutaneous lymphomas and for voluminous lymphadenopathies. (authors)

  1. Irradiation influence on the bone marrow function of patients who received external radiotherapy to the bone metastasis lesion

    International Nuclear Information System (INIS)

    The effects of external radiotherapy (EBRT) on the bone marrow function were studied in 49 patients who received regional EBRT to the bone metastatic lesions. The platelet counts showed gradual but significant decrease to 88.0% at 12 weeks after completing the irradiation compared to the baselines. The lymphocyte counts decreased rapidly and significantly to 74.3% at 2 weeks after starting the irradiation but recovered to the baseline levels at 12 weeks after the irradiation. The decreases in the lymphocytes showed weak correlations with the widths of the irradiation areas and the lymphocytes counts before the irradiation, respectively. There found no significant decrease in the other blood cell counts which provoked serious adverse events due to the EBRT. These results suggest that the regional irradiation to the bone metastatic lesions would not cause serious nor long-term myelosuppression. (author)

  2. Adaptive Motion Compensation in Radiotherapy

    CERN Document Server

    Murphy, Martin J

    2011-01-01

    External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

  3. Effects of beam interruption time on tumor control probability in single-fractionated carbon-ion radiotherapy for non-small cell lung cancer

    International Nuclear Information System (INIS)

    Carbon-ion radiotherapy treatment plans are designed on the assumption that the beams are delivered instantaneously, irrespective of actual dose-delivery time structure in a treatment session. As the beam lines are fixed in the vertical and horizontal directions at our facility, beam delivery is interrupted in multi-field treatment due to the necessity of patient repositioning within the fields. Single-fractionated treatment for non-small cell lung cancer (NSCLC) is such a case, in which four treatment fields in multiple directions are delivered in one session with patient repositioning during the session. The purpose of this study was to investigate the effects of the period of dose delivery, including interruptions due to patient repositioning, on tumor control probability (TCP) of NSCLC. All clinical doses were weighted by relative biological effectiveness (RBE) evaluated for instantaneous irradiation. The rate equations defined in the microdosimetric kinetic model (MKM) for primary lesions induced in DNA were applied to the single-fractionated treatment of NSCLC. Treatment plans were made for an NSCLC case for various prescribed doses ranging from 25 to 50 Gy (RBE), on the assumption of instantaneous beam delivery. These plans were recalculated by varying the interruption time τ ranging from 0 to 120 min between the second and third fields for continuous irradiations of 3 min per field based on the MKM. The curative doses that would result in a TCP of 90% were deduced for the respective interruption times. The curative dose was 34.5 Gy (RBE) for instantaneous irradiation and 36.6 Gy (RBE), 39.2 Gy (RBE), 41.2 Gy (RBE), 43.3 Gy (RBE) and 44.4 Gy (RBE) for τ = 0 min, 15 min, 30 min, 60 min and 120 min, respectively. The realistic biological effectiveness of therapeutic carbon-ion beam decreased with increasing interruption time. These data suggest that the curative dose can increase by 20% or more compared to the planned dose if

  4. Effects of beam interruption time on tumor control probability in single-fractionated carbon-ion radiotherapy for non-small cell lung cancer

    Science.gov (United States)

    Inaniwa, T.; Kanematsu, N.; Suzuki, M.; Hawkins, R. B.

    2015-05-01

    Carbon-ion radiotherapy treatment plans are designed on the assumption that the beams are delivered instantaneously, irrespective of actual dose-delivery time structure in a treatment session. As the beam lines are fixed in the vertical and horizontal directions at our facility, beam delivery is interrupted in multi-field treatment due to the necessity of patient repositioning within the fields. Single-fractionated treatment for non-small cell lung cancer (NSCLC) is such a case, in which four treatment fields in multiple directions are delivered in one session with patient repositioning during the session. The purpose of this study was to investigate the effects of the period of dose delivery, including interruptions due to patient repositioning, on tumor control probability (TCP) of NSCLC. All clinical doses were weighted by relative biological effectiveness (RBE) evaluated for instantaneous irradiation. The rate equations defined in the microdosimetric kinetic model (MKM) for primary lesions induced in DNA were applied to the single-fractionated treatment of NSCLC. Treatment plans were made for an NSCLC case for various prescribed doses ranging from 25 to 50 Gy (RBE), on the assumption of instantaneous beam delivery. These plans were recalculated by varying the interruption time τ ranging from 0 to 120 min between the second and third fields for continuous irradiations of 3 min per field based on the MKM. The curative doses that would result in a TCP of 90% were deduced for the respective interruption times. The curative dose was 34.5 Gy (RBE) for instantaneous irradiation and 36.6 Gy (RBE), 39.2 Gy (RBE), 41.2 Gy (RBE), 43.3 Gy (RBE) and 44.4 Gy (RBE) for τ = 0 min, 15 min, 30 min, 60 min and 120 min, respectively. The realistic biological effectiveness of therapeutic carbon-ion beam decreased with increasing interruption time. These data suggest that the curative dose can increase by 20% or more compared to the planned dose if the

  5. Commissioning of radiotherapy treatment planning systems: Testing for typical external beam treatment techniques. Report of the Coordinated Research Project (CRP) on Development of Procedures for Quality Assurance of Dosimetry Calculations in Radiotherapy

    International Nuclear Information System (INIS)

    Quality Assurance (QA) in the radiation therapy treatment planning process is essential to ensure accurate dose delivery to the patient and to minimize the possibility of accidental exposure. Computerized radiotherapy treatment planning systems (RTPSs) are now widely available in both industrialised and developing countries so, it is of special importance to support hospitals in the IAEA Member States in developing procedures for acceptance testing, commissioning and ongoing QA of their RTPSs. Responding to these needs, a group of experts developed a comprehensive report, the IAEA Technical Reports Series No 430 'Commissioning and quality assurance of computerized planning systems for radiation treatment of cancer', that provides the general framework and describes a large number of tests and procedures to be considered by the RTPS users. To provide practical guidance for implementation of IAEA Technical Reports Series No. 430 in radiotherapy hospitals and particularly in those with limited resources, a coordinated research project (CRP E2.40.13) 'Development of procedures for dosimetry calculation in radiotherapy' was established. The main goal of the project was to create a set of practical acceptance and commissioning tests for dosimetry calculations in radiotherapy, defined in a dedicated protocol. Two specific guidance publications that were developed in the framework of the Coordinated Research Project E2.40.13 are based on guidelines described in the IAEA Technical Report Series No. 430 and provide a step-by-step description for users at hospitals or cancer centres how to implement acceptance and commissioning procedures for their RTPSs. The first publication, 'Specification and acceptance testing of radiotherapy treatment planning systems' IAEA-TECDOC-1540 uses the International Electrotechnical Commission (IEC) standard IEC 62083 as its basis and addresses the procedures for specification and acceptance testing of RTPSs to be used by both manufacturers and

  6. Commissioning of Radiotherapy Treatment Planning Systems: Testing for Typical External Beam Treatment Techniques. Report of the Coordinated Research Project (CRP) on Development of Procedures for Quality Assurance of Dosimetry Calculations in Radiotherapy

    International Nuclear Information System (INIS)

    Quality Assurance (QA) in the radiation therapy treatment planning process is essential to ensure accurate dose delivery to the patient and to minimize the possibility of accidental exposure. Computerized radiotherapy treatment planning systems (RTPSs) are now widely available in both industrialised and developing countries so, it is of special importance to support hospitals in the IAEA Member States in developing procedures for acceptance testing, commissioning and ongoing QA of their RTPSs. Responding to these needs, a group of experts developed a comprehensive report, the IAEA Technical Reports Series No 430 'Commissioning and quality assurance of computerized planning systems for radiation treatment of cancer', that provides the general framework and describes a large number of tests and procedures to be considered by the RTPS users. To provide practical guidance for implementation of IAEA Technical Reports Series No. 430 in radiotherapy hospitals and particularly in those with limited resources, a coordinated research project (CRP E2.40.13) 'Development of procedures for dosimetry calculation in radiotherapy' was established. The main goal of the project was to create a set of practical acceptance and commissioning tests for dosimetry calculations in radiotherapy, defined in a dedicated protocol. Two specific guidance publications that were developed in the framework of the Coordinated Research Project E2.40.13 are based on guidelines described in the IAEA Technical Report Series No. 430 and provide a step-by-step description for users at hospitals or cancer centres how to implement acceptance and commissioning procedures for their RTPSs. The first publication, 'Specification and acceptance testing of radiotherapy treatment planning systems' IAEA-TECDOC-1540 uses the International Electrotechnical Commission (IEC) standard IEC 62083 as its basis and addresses the procedures for specification and acceptance testing of RTPSs to be

  7. A novel approach in electron beam radiation therapy of lips carcinoma: A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Shokrani, Parvaneh [Medical Physics and Medical Engineering Department, School of Medicine, Isfahan University of Medical Sciences, Isfahan 81746-73461 (Iran, Islamic Republic of); Baradaran-Ghahfarokhi, Milad [Medical Physics and Medical Engineering Department, School of Medicine, Isfahan University of Medical Sciences, Isfahan 81746-73461, Iran and Medical Radiation Engineering Department, Faculty of Advanced Sciences and Technologies, Isfahan University, Isfahan 81746-73441 (Iran, Islamic Republic of); Zadeh, Maryam Khorami [Medical Physics Department, School of Medicine, Ahwaz Jundishapour University of Medical Sciences, Ahwaz 15794-61357 (Iran, Islamic Republic of)

    2013-04-15

    Purpose: Squamous cell carcinoma (SCC) is commonly treated by electron beam radiotherapy (EBRT) followed by a boost via brachytherapy. Considering the limitations associated with brachytherapy, in this study, a novel boosting technique in EBRT of lip carcinoma using an internal shield as an internal dose enhancer tool (IDET) was evaluated. An IDET is referred to a partially covered internal shield located behind the lip. It was intended to show that while the backscattered electrons are absorbed in the portion covered with a low atomic number material, they will enhance the target dose in the uncovered area. Methods: Monte-Carlo models of 6 and 8 MeV electron beams were developed using BEAMnrc code and were validated against experimental measurements. Using the developed models, dose distributions in a lip phantom were calculated and the effect of an IDET on target dose enhancement was evaluated. Typical lip thicknesses of 1.5 and 2.0 cm were considered. A 5 Multiplication-Sign 5 cm{sup 2} of lead covered by 0.5 cm of polystyrene was used as an internal shield, while a 4 Multiplication-Sign 4 cm{sup 2} uncovered area of the shield was used as the dose enhancer. Results: Using the IDET, the maximum dose enhancement as a percentage of dose at d{sub max} of the unshielded field was 157.6% and 136.1% for 6 and 8 MeV beams, respectively. The best outcome was achieved for lip thickness of 1.5 cm and target thickness of less than 0.8 cm. For lateral dose coverage of planning target volume, the 80% isodose curve at the lip-IDET interface showed a 1.2 cm expansion, compared to the unshielded field. Conclusions: This study showed that a boost concomitant EBRT of lip is possible by modifying an internal shield into an IDET. This boosting method is especially applicable to cases in which brachytherapy faces limitations, such as small thicknesses of lips and targets located at the buccal surface of the lip.

  8. A novel approach in electron beam radiation therapy of lips carcinoma: A Monte Carlo study

    International Nuclear Information System (INIS)

    Purpose: Squamous cell carcinoma (SCC) is commonly treated by electron beam radiotherapy (EBRT) followed by a boost via brachytherapy. Considering the limitations associated with brachytherapy, in this study, a novel boosting technique in EBRT of lip carcinoma using an internal shield as an internal dose enhancer tool (IDET) was evaluated. An IDET is referred to a partially covered internal shield located behind the lip. It was intended to show that while the backscattered electrons are absorbed in the portion covered with a low atomic number material, they will enhance the target dose in the uncovered area. Methods: Monte-Carlo models of 6 and 8 MeV electron beams were developed using BEAMnrc code and were validated against experimental measurements. Using the developed models, dose distributions in a lip phantom were calculated and the effect of an IDET on target dose enhancement was evaluated. Typical lip thicknesses of 1.5 and 2.0 cm were considered. A 5 × 5 cm2 of lead covered by 0.5 cm of polystyrene was used as an internal shield, while a 4 × 4 cm2 uncovered area of the shield was used as the dose enhancer. Results: Using the IDET, the maximum dose enhancement as a percentage of dose at dmax of the unshielded field was 157.6% and 136.1% for 6 and 8 MeV beams, respectively. The best outcome was achieved for lip thickness of 1.5 cm and target thickness of less than 0.8 cm. For lateral dose coverage of planning target volume, the 80% isodose curve at the lip-IDET interface showed a 1.2 cm expansion, compared to the unshielded field. Conclusions: This study showed that a boost concomitant EBRT of lip is possible by modifying an internal shield into an IDET. This boosting method is especially applicable to cases in which brachytherapy faces limitations, such as small thicknesses of lips and targets located at the buccal surface of the lip.

  9. Improving the neutron-to-photon discrimination capability of detectors used for neutron dosimetry in high energy photon beam radiotherapy.

    Science.gov (United States)

    Irazola, L; Terrón, J A; Bedogni, R; Pola, A; Lorenzoli, M; Sánchez-Nieto, B; Gómez, F; Sánchez-Doblado, F

    2016-09-01

    The increasing interest of the medical community to radioinduced second malignancies due to photoneutrons in patients undergoing high-energy radiotherapy, has stimulated in recent years the study of peripheral doses, including the development of some dedicated active detectors. Although these devices are designed to respond to neutrons only, their parasitic photon response is usually not identically zero and anisotropic. The impact of these facts on measurement accuracy can be important, especially in points close to the photon field-edge. A simple method to estimate the photon contribution to detector readings is to cover it with a thermal neutron absorber with reduced secondary photon emission, such as a borated rubber. This technique was applied to the TNRD (Thermal Neutron Rate Detector), recently validated for thermal neutron measurements in high-energy photon radiotherapy. The positive results, together with the accessibility of the method, encourage its application to other detectors and different clinical scenarios. PMID:27337649

  10. Dose escalation in the radiotherapy of non-small-cell lung cancer with aperture-based intensity modulation and photon beam energy optimization for non-preselected patients

    International Nuclear Information System (INIS)

    Purpose: To verify the potential of aperture-based intensity-modulated radiotherapy (AB-IMRT) to realize dose escalation plans for non-preselected non-small-cell lung cancer (NSCLC) patients, using photon beam energy optimization. Methods and materials: Seven cases of NSCLC were retrospectively studied. Clinical reference plans were made at 60 Gy by an experienced dosimetrist. Dose escalation was applied to PTV2, a subvolume within the main PTV1. Escalation plans were optimized by considering beam angles (table and gantry), energy (6 and 23 MV) and weights, for an increasing dose to the PTV2, starting from 66 Gy and keeping 30 fractions. Results: In five cases, doses over 78 Gy could be achieved before exceeding organs at risk (OARs) standard tolerance. Peripheral overdosages, as well as lung and spinal cord tolerance doses, limited escalation. Means ± SD V95% parameters were (97.3 ± 0.9)% for PTV1s and (96.7 ± 2.2)% for PTV2s. Doses to OARs were also maintained at acceptable levels. Optimized plans made use of both low- and high-energy beams and had a similar number of monitor units compared to the 60 Gy clinical plans. Conclusions: The AB-IMRT system can successfully realize dose escalation for a sizeable number of cases. Plans produced contained few large segments, and are applicable to a wide range of tumor volumes and locations.

  11. Concurrent Radiotherapy and Gemcitabine for Unresectable Pancreatic Adenocarcinoma: Impact of Adjuvant Chemotherapy on Survival

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Kazuhiko, E-mail: kogawa@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, Okinawa (Japan); Ito, Yoshinori [Department of Radiation Oncology, National Cancer Center, Tokyo (Japan); Hirokawa, Naoki [Department of Radiology, Sapporo Medical University, Sapporo (Japan); Shibuya, Keiko [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University, Kyoto (Japan); Kokubo, Masaki [Department of Radiation Oncology, Institute of Biomedical Research and Innovation Hospital, Kobe (Japan); Ogo, Etsuyo [Department of Radiation Oncology, Kurume University, Kurume (Japan); Shibuya, Hitoshi [Department of Radiology, Tokyo Medical and Dental University, Tokyo (Japan); Saito, Tsutomu [Department of Radiation Oncology, Nihon University Itabashi Hospital, Tokyo (Japan); Onishi, Hiroshi [Department of Radiology, Yamanashi University, Yamanashi (Japan); Karasawa, Katsuyuki [Department of Radiation Oncology, Tokyo Metropolitan Komagome Hospital, Tokyo (Japan); Nemoto, Kenji [Department of Radiation Oncology, Yamagata University, Yamagata (Japan); Nishimura, Yasumasa [Department of Radiation Oncology, Kinki University School of Medicine, Osaka (Japan)

    2012-06-01

    Purpose: To retrospectively analyze results of concurrent chemoradiotherapy (CCRT) using gemcitabine (GEM) for unresectable pancreatic adenocarcinoma. Methods and Materials: Records of 108 patients treated with concurrent external beam radiotherapy (EBRT) and GEM were reviewed. The median dose of EBRT in all 108 patients was 50.4 Gy (range, 3.6-60.8 Gy), usually administered in conventional fractionations (1.8-2 Gy/day). During radiotherapy, most patients received GEM at a dosage of 250 to 350 mg/m{sup 2} intravenously weekly for approximately 6 weeks. After CCRT, 59 patients (54.6%) were treated with adjuvant chemotherapy (AC), mainly with GEM. The median follow-up for all 108 patients was 11.0 months (range, 0.4-37.9 months). Results: Initial responses after CCRT for 85 patients were partial response: 26 patients, no change: 51 patients and progressive disease: 8 patients. Local progression was observed in 35 patients (32.4%), and the 2-year local control (LC) rate in all patients was 41.9%. Patients treated with total doses of 50 Gy or more had significantly more favorable LC rates (2-year LC rate, 42.9%) than patients treated with total doses of less than 50 Gy (2-year LC rate, 29.6%). Regional lymph node recurrence was found in only 1 patient, and none of the 57 patients with clinical N0 disease had regional lymph node recurrence. The 2-year overall survival (OS) rate and the median survival time in all patients were 23.5% and 11.6 months, respectively. Patients treated with AC had significantly more favorable OS rates (2-year OS, 31.8%) than those treated without AC (2-year OS, 12.4%; p < 0.0001). On multivariate analysis, AC use and clinical T stage were significant prognostic factors for OS. Conclusions: CCRT using GEM yields a relatively favorable LC rate for unresectable pancreatic adenocarcinoma, and CCRT with AC conferred a survival benefit compared to CCRT without AC.

  12. Concurrent Radiotherapy and Gemcitabine for Unresectable Pancreatic Adenocarcinoma: Impact of Adjuvant Chemotherapy on Survival

    International Nuclear Information System (INIS)

    Purpose: To retrospectively analyze results of concurrent chemoradiotherapy (CCRT) using gemcitabine (GEM) for unresectable pancreatic adenocarcinoma. Methods and Materials: Records of 108 patients treated with concurrent external beam radiotherapy (EBRT) and GEM were reviewed. The median dose of EBRT in all 108 patients was 50.4 Gy (range, 3.6–60.8 Gy), usually administered in conventional fractionations (1.8–2 Gy/day). During radiotherapy, most patients received GEM at a dosage of 250 to 350 mg/m2 intravenously weekly for approximately 6 weeks. After CCRT, 59 patients (54.6%) were treated with adjuvant chemotherapy (AC), mainly with GEM. The median follow-up for all 108 patients was 11.0 months (range, 0.4–37.9 months). Results: Initial responses after CCRT for 85 patients were partial response: 26 patients, no change: 51 patients and progressive disease: 8 patients. Local progression was observed in 35 patients (32.4%), and the 2-year local control (LC) rate in all patients was 41.9%. Patients treated with total doses of 50 Gy or more had significantly more favorable LC rates (2-year LC rate, 42.9%) than patients treated with total doses of less than 50 Gy (2-year LC rate, 29.6%). Regional lymph node recurrence was found in only 1 patient, and none of the 57 patients with clinical N0 disease had regional lymph node recurrence. The 2-year overall survival (OS) rate and the median survival time in all patients were 23.5% and 11.6 months, respectively. Patients treated with AC had significantly more favorable OS rates (2-year OS, 31.8%) than those treated without AC (2-year OS, 12.4%; p < 0.0001). On multivariate analysis, AC use and clinical T stage were significant prognostic factors for OS. Conclusions: CCRT using GEM yields a relatively favorable LC rate for unresectable pancreatic adenocarcinoma, and CCRT with AC conferred a survival benefit compared to CCRT without AC.

  13. Dosimetric properties characterization of silicon diodes used in photon beam radiotherapy; Caracterizacao das propriedades dosimetricas de diodos de silicio empregados em radioterapia com fotons

    Energy Technology Data Exchange (ETDEWEB)

    Bizetto, Cesar Augusto

    2013-07-01

    In the current work it was studied the performance of epitaxial (EPI) and float zone (FZ) silicon diodes as on-line dosimeters for megavoltage (EPI diode) and orthovoltage (EPI and FZ diode) photon beam radiotherapy. In order to be used as dosimeters the diodes were enclosed in black polymethylmethacrylate (PMMA) probes. The devices were then connected, on photovoltaic mode, to an electrometer KeithleyÒ 6517B to allow measurements of the photocurrent. The irradiations were performed with 6 and 18 MV photon beams (Siemens PrimusÒ linear accelerator), 6 and 15 MV (Novalis TXÒ) and 10, 25, 30 and 50 kV of a Pantak / Seifert X ray radiation device. During the measurements with the Siemens PrimusÒ the diodes were held between PMMA plates placed at 10.0 cm depth. When using Novalis TXÒ the devices were held between solid water plates placed at 50 cm depth. In both cases the diodes were centered in a radiation field of 10 x 10 cm{sup 2}, with the source-to-surface distance (SSD) kept at 100 cm. In measurements with orthovoltage photon beams the diodes were placed 50.0 cm from the tube in a radiation field of 8 cm diameter. The dose-rate dependency was studied for 6 and 15 MV (varying the dose-rate from 100 to 600 monitor units per minute) and for the 50 kV beam by varying the current tube from 2 to 20 mA. All devices showed linear response with dose rate and, within uncertainties the charge collected is independent of dose rate. The current signals induced showed good instantaneous repeatability of the diodes, characterized by coefficients of variation of current (CV) smaller than 1.14% (megavoltage beams) and 0.15% for orthovoltage beams and coefficients of variation of charge (CV) smaller than 1.84% (megavoltage beams) and 1.67% (orthovoltage beams). The dose response curves were quite linear with linear correlation coefficients better than 0.9999 for all diodes. (author)

  14. Dosimetric properties characterization of silicon diodes used in photon beam radiotherapy; Caracterizacao das propriedades dosimetricas de diodos de silicio empregados em radioterapia com feixe de fotons

    Energy Technology Data Exchange (ETDEWEB)

    Bizetto, Cesar Augusto

    2013-07-01

    In the current work it was studied the performance of epitaxial (EPI) and float zone (FZ) silicon diodes as on-line dosimeters for megavoltage (EPI diode) and orthovoltage (EPI and FZ diode) photon beam radiotherapy. In order to be used as dosimeters the diodes were enclosed in black polymethylmethacrylate (PMMA) probes. The devices were then connected, on photovoltaic mode, to an electrometer Keithley Registered-Sign 6517B to allow measurements of the photocurrent. The irradiations were performed with 6 and 18 MV photon beams (Siemens Primus Registered-Sign linear accelerator), 6 and 15 MV (Novalis TX Registered-Sign ) and 10, 25, 30 and 50 kV of a Pantak / Seifert X ray radiation device. During the measurements with the Siemens Primus the diodes were held between PMMA plates placed at 10.0 cm depth. When using Novalis TX Registered-Sign the devices were held between solid water plates placed at 50 cm depth. In both cases the diodes were centered in a radiation field of 10 x 10 cm{sup 2}, with the source-to-surface distance (SSD) kept at 100 cm. In measurements with orthovoltage photon beams the diodes were placed 50.0 cm from the tube in a radiation field of 8 cm diameter. The dose-rate dependency was studied for 6 and 15 MV (varying the dose-rate from 100 to 600 monitor units per minute) and for the 50 kV beam by varying the current tube from 2 to 20 mA. All devices showed linear response with dose rate and, within uncertainties the charge collected is independent of dose rate. The current signals induced showed good instantaneous repeatability of the diodes, characterized by coefficients of variation of current (CV) smaller than 1.14% (megavoltage beams) and 0.15% for orthovoltage beams and coefficients of variation of charge (CV) smaller than 1.84% (megavoltage beams) and 1.67% (orthovoltage beams). The dose response curves were quite linear with linear correlation coefficients better than 0.9999 for all diodes. (author)

  15. An in-silico comparison of proton beam and IMRT for postoperative radiotherapy in completely resected stage IIIA non-small cell lung cancer

    International Nuclear Information System (INIS)

    Post-operative radiotherapy (PORT) for stage IIIA completely-resected non-small cell lung cancer (CR-NSCLC) has been shown to improve local control; however, it is unclear that this translates into a survival benefit. One explanation is that the detrimental effect of PORT on critical organs at risk (OARs) negates its benefit. This study reports an in-silico comparative analysis of passive scattering proton therapy (PSPT)- and intensity modulated proton therapy (IMPT) with intensity modulated photon beam radiotherapy (IMRT) PORT. The computed tomography treatment planning scans of ten patients with pathologic stage IIIA CR-NSCLC treated with IMRT were used. IMRT, PSPT, and IMPT plans were generated and analyzed for dosimetric endpoints. The proton plans were constructed with two or three beams. All plans were optimized to deliver 50.4 Gy(RBE) in 1.8 Gy(RBE) fractions to the target volume. IMPT leads to statistically significant reductions in maximum spinal cord, mean lung dose, lung volumes treated to 5, 10, 20, and 30 Gy (V5, V10, V20, V30), mean heart dose, and heart volume treated to 40 Gy (V40), when compared with IMRT or PSPT. PSPT reduced lung V5 but increased lung V20, V30, and heart and esophagus V40. IMPT demonstrates a large decrease in dose to all OARs. PSPT, while reducing the low-dose lung bath, increases the volume of lung receiving high dose. Reductions are seen in dosimetric parameters predictive of radiation pneumonitis and cardiac morbidity and mortality. This reduction may correlate with a decrease in dose-limiting toxicity and improve the therapeutic ratio

  16. The feasibility and safety of high-intensity focused ultrasound combined with low-dose external beam radiotherapy as supplemental therapy for advanced prostate cancer following hormonal therapy

    Institute of Scientific and Technical Information of China (English)

    Rui-Yi Wu; Guo-Min Wang; Lei Xu; Bo-Heng Zhang; Ye-Qing Xu; Zhao-Chong Zeng; Bing Chen

    2011-01-01

    The aim of this study was to investigate the feasibility and safety of high-intensity focused ultrasound (HIFU) combined with (+) low-dose external beam radiotherapy (LRT) as supplemental therapy for advanced prostate cancer (PCa) following hormonal therapy (HT). Our definition of HIFU+LRT refers to treating primary tumour lesions with HIFU in place of reduced field boost irradiation to the prostate, while retaining four-field box irradiation to the pelvis in conventional-dose external beam radiotherapy (CRT). We performed a prospective, controlled and non-randomized study on 120 patients with advanced PCa after HT who received HIFU, CRT, HIFU+LRT and HT alone, respectively. CT/MR imaging showed the primary tumours and pelvic lymph node metastases visibly shrank or even disappeared after HIFU+LRT treatment. There were significant differences among four groups with regard to overall survival (OS) and disease-specific survival (DSS) curves (P=0.018 and 0.015). Further comparison between each pair of groups suggested that the long-term DSS of the HIFU+LRT group was higher than those of the other three groups, but there was no significant difference between the HIFU+LRT group and the CRT group. Multivariable Cox's proportional hazard model showed that both HIFU+LRT and CRT were independently associated with DSS (P=0.001 and 0.035) and had protective effects with regard to the risk of death. Compared with CRT, HIFU+LRT significantly decreased incidences of radiation-related late gastrointestinal (GI) and genitourinary (GU) toxicity grade ≥II. In conclusion, long-term survival of patients with advanced PCa benefited from strengthening local control of primary tumour and regional lymph node metastases after HT. As an alternative to CRT, HIFU+LRT showed good efficacy and better safety.

  17. Peripheral photon and neutron doses from prostate cancer external beam irradiation.

    Science.gov (United States)

    Bezak, Eva; Takam, Rundgham; Marcu, Loredana G

    2015-12-01

    Peripheral photon and neutron doses from external beam radiotherapy (EBRT) are associated with increased risk of carcinogenesis in the out-of-field organs; thus, dose estimations of secondary radiation are imperative. Peripheral photon and neutron doses from EBRT of prostate carcinoma were measured in Rando phantom. (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P glass-rod thermoluminescence dosemeters (TLDs) were inserted in slices of a Rando phantom followed by exposure to 80 Gy with 18-MV photon four-field 3D-CRT technique. The TLDs were calibrated using 6- and 18-MV X-ray beam. Neutron dose equivalents measured with CR-39 etch-track detectors were used to derive readout-to-neutron dose conversion factor for (6)LiF:Mg,Cu,P TLDs. Average neutron dose equivalents per 1 Gy of isocentre dose were 3.8±0.9 mSv Gy(-1) for thyroid and 7.0±5.4 mSv Gy(-1) for colon. For photons, the average dose equivalents per 1 Gy of isocentre dose were 0.2±0.1 mSv Gy(-1) for thyroid and 8.1±9.7 mSv Gy(-1) for colon. Paired (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P TLDs can be used to measure photon and neutron doses simultaneously. Organs in close proximity to target received larger doses from photons than those from neutrons whereas distally located organs received higher neutron versus photon dose. PMID:25564673

  18. A pilot study of preoperative continuous infusion 5-fluorouracil, external microwave hyperthermia, and external beam radiotherapy for treatment of locally advanced, unresectable, or recurrent rectal cancer

    International Nuclear Information System (INIS)

    Purpose: To determine the feasibility of combining external beam radiotherapy, continuous infusion 5-fluorouracil (5-FU), and external microwave hyperthermia in patients with locally advanced, unresectable, or recurrent adenocarcinoma of the rectum. Methods and Materials: From 7/95 through 2/99, 15 patients were enrolled in the study. The treatment regimen consisted of continuous infusion 5-FU 250 mg/m2/d 7 days/week beginning on day 1, external beam radiotherapy to the pelvis, 4500 cGy, 180 cGy/d 5 days/week using a 3 or 4-field technique, and external microwave hyperthermia on days 3, 8, 15, 22, and 29. Chemotherapy was stopped on the last day of radiotherapy. Surgical resection, if feasible, was scheduled 3-6 weeks after completing thermochemoradiotherapy. For this regimen to be considered feasible, no more than 2 of the 15 patients should fail to complete therapy due to life-threatening toxicity. Toxicity was scored using National Cancer Institute Criteria. Results: All patients completed the chemoradiotherapy portion of the protocol. Eleven of the 15 patients completed all 5 hyperthermia treatments. Of the 4 patients who did not receive the full course of hyperthermia, only 1 patient had treatment stopped due to life-threatening toxicity. The other 3 patients did not complete hyperthermia due to scheduling errors (n = 2) or patient request (n = 1). Five of 15 patients required a treatment interruption due to toxicity no. >=no. Grade 3. Seven patients experienced lesser degrees of toxicity which did not require treatment interruption. Three patients experienced no side effects. The most common toxicities were dermatitis and diarrhea. Of the 14 patients in whom surgery was planned, 11 (79%) were resectable. There was one pathologic complete response. Conclusions: It is feasible to deliver thermochemoradiotherapy, as prescribed in this study, to patients with locally advanced, unresectable, or recurrent rectal cancer. The therapy is moderately toxic, with one

  19. Integration of PET-CT and cone-beam CT for image-guided radiotherapy with high image quality and registration accuracy

    Science.gov (United States)

    Wu, T.-H.; Liang, C.-H.; Wu, J.-K.; Lien, C.-Y.; Yang, B.-H.; Huang, Y.-H.; Lee, J. J. S.

    2009-07-01

    Hybrid positron emission tomography-computed tomography (PET-CT) system enhances better differentiation of tissue uptake of 18F-fluorodeoxyglucose (18F-FDG) and provides much more diagnostic value in the non-small-cell lung cancer and nasopharyngeal carcinoma (NPC). In PET-CT, high quality CT images not only offer diagnostic value on anatomic delineation of the tissues but also shorten the acquisition time for attenuation correction (AC) compared with PET-alone imaging. The linear accelerators equipped with the X-ray cone-beam computed tomography (CBCT) imaging system for image-guided radiotherapy (IGRT) provides excellent verification on position setup error. The purposes of our study were to optimize the CT acquisition protocols of PET-CT and to integrate the PET-CT and CBCT for IGRT. The CT imaging parameters were modified in PET-CT for increasing the image quality in order to enhance the diagnostic value on tumour delineation. Reproducibility and registration accuracy via bone co-registration algorithm between the PET-CT and CBCT were evaluated by using a head phantom to simulate a head and neck treatment condition. Dose measurement in computed tomography dose index (CTDI) was also estimated. Optimization of the CT acquisition protocols of PET-CT was feasible in this study. Co-registration accuracy between CBCT and PET-CT on axial and helical modes was in the range of 1.06 to 2.08 and 0.99 to 2.05 mm, respectively. In our result, it revealed that the accuracy of the co-registration with CBCT on helical mode was more accurate than that on axial mode. Radiation doses in CTDI were 4.76 to 18.5 mGy and 4.83 to 18.79 mGy on axial and helical modes, respectively. Registration between PET-CT and CBCT is a state-of-the-art registration technology which could provide much information on diagnosis and accurate tumour contouring on radiotherapy while implementing radiotherapy procedures. This novelty technology of PET-CT and cone-beam CT integration for IGRT may have a

  20. Integration of PET-CT and cone-beam CT for image-guided radiotherapy with high image quality and registration accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, T-H [Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, No. 110, Sec.1, Jianguo N.Rd, Taichung City 40201, Taiwan (China); Liang, C-H [Agfa Healthcare Systems Taiwan Co., Ltd., 6F, 237 Sung Chiang Road, Taipei, 104 Taiwan (China); Wu, J-K [Division of Radiation Oncology, Department of Oncology, and Cancer Research Center, National Taiwan University Hospital, No.7 Chung San South Road, Taipei, 104 Taiwan (China); Lien, C-Y [Institute of Biomedical Engineering, National Yang Ming University, No. 155, Sec.2, Linong Street, Taipei, 112 Taiwan (China); Yang, B-H; Lee, J J S [Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, No. 155, Sec.2, Linong Street, Taipei, 112 Taiwan (China); Huang, Y-H [Department of Medical Imaing and Radiological Sciences, I-Shou University, No. 8, Yida Rd., Yanchao Township, Kaohsiung County 82445, Taiwan (China)], E-mail: jslee@ym.edu.tw

    2009-07-15

    Hybrid positron emission tomography-computed tomography (PET-CT) system enhances better differentiation of tissue uptake of {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) and provides much more diagnostic value in the non-small-cell lung cancer and nasopharyngeal carcinoma (NPC). In PET-CT, high quality CT images not only offer diagnostic value on anatomic delineation of the tissues but also shorten the acquisition time for attenuation correction (AC) compared with PET-alone imaging. The linear accelerators equipped with the X-ray cone-beam computed tomography (CBCT) imaging system for image-guided radiotherapy (IGRT) provides excellent verification on position setup error. The purposes of our study were to optimize the CT acquisition protocols of PET-CT and to integrate the PET-CT and CBCT for IGRT. The CT imaging parameters were modified in PET-CT for increasing the image quality in order to enhance the diagnostic value on tumour delineation. Reproducibility and registration accuracy via bone co-registration algorithm between the PET-CT and CBCT were evaluated by using a head phantom to simulate a head and neck treatment condition. Dose measurement in computed tomography dose index (CTDI) was also estimated. Optimization of the CT acquisition protocols of PET-CT was feasible in this study. Co-registration accuracy between CBCT and PET-CT on axial and helical modes was in the range of 1.06 to 2.08 and 0.99 to 2.05 mm, respectively. In our result, it revealed that the accuracy of the co-registration with CBCT on helical mode was more accurate than that on axial mode. Radiation doses in CTDI were 4.76 to 18.5 mGy and 4.83 to 18.79 mGy on axial and helical modes, respectively. Registration between PET-CT and CBCT is a state-of-the-art registration technology which could provide much information on diagnosis and accurate tumour contouring on radiotherapy while implementing radiotherapy procedures. This novelty technology of PET-CT and cone-beam CT integration for IGRT

  1. Integration of PET-CT and cone-beam CT for image-guided radiotherapy with high image quality and registration accuracy

    International Nuclear Information System (INIS)

    Hybrid positron emission tomography-computed tomography (PET-CT) system enhances better differentiation of tissue uptake of 18F-fluorodeoxyglucose (18F-FDG) and provides much more diagnostic value in the non-small-cell lung cancer and nasopharyngeal carcinoma (NPC). In PET-CT, high quality CT images not only offer diagnostic value on anatomic delineation of the tissues but also shorten the acquisition time for attenuation correction (AC) compared with PET-alone imaging. The linear accelerators equipped with the X-ray cone-beam computed tomography (CBCT) imaging system for image-guided radiotherapy (IGRT) provides excellent verification on position setup error. The purposes of our study were to optimize the CT acquisition protocols of PET-CT and to integrate the PET-CT and CBCT for IGRT. The CT imaging parameters were modified in PET-CT for increasing the image quality in order to enhance the diagnostic value on tumour delineation. Reproducibility and registration accuracy via bone co-registration algorithm between the PET-CT and CBCT were evaluated by using a head phantom to simulate a head and neck treatment condition. Dose measurement in computed tomography dose index (CTDI) was also estimated. Optimization of the CT acquisition protocols of PET-CT was feasible in this study. Co-registration accuracy between CBCT and PET-CT on axial and helical modes was in the range of 1.06 to 2.08 and 0.99 to 2.05 mm, respectively. In our result, it revealed that the accuracy of the co-registration with CBCT on helical mode was more accurate than that on axial mode. Radiation doses in CTDI were 4.76 to 18.5 mGy and 4.83 to 18.79 mGy on axial and helical modes, respectively. Registration between PET-CT and CBCT is a state-of-the-art registration technology which could provide much information on diagnosis and accurate tumour contouring on radiotherapy while implementing radiotherapy procedures. This novelty technology of PET-CT and cone-beam CT integration for IGRT may have a

  2. Intercomparison of ionization chambers in standard X-ray beams, at radiotherapy, diagnostic radiology and radioprotection levels; Intercomparacao de camaras de ionizacao em feixes padroes de raios X, niveis radioterapia, radiodiagnostico e radioprotecao

    Energy Technology Data Exchange (ETDEWEB)

    Bessa, Ana Carolina Moreira de

    2006-07-01

    Since the calibration of radiation measurement instruments and the knowledge of their major characteristics are very important subjects, several different types of ionization chambers were intercompared in terms of their calibration coefficients and their energy dependence, in radiotherapy, diagnostic radiology and radioprotection standard beams. An intercomparison of radionuclide calibrators for nuclear medicine was performed, using three radionuclides: {sup 67}Ga, {sup 201}Tl and {sup 99m}Tc; the results obtained were all within the requirements of the national standard CNEN-NE-3.05. In order to complete the range of radiation qualities of the Calibration Laboratory of IPEN, standard radiation beam qualities, radiation protection and low energy radiation therapy levels, were established, according international recommendations. Three methodologies for the calibration of unsealed ionization chambers in X-ray beams were studied and compared. A set of Victoreen ionization chambers, specially designed for use in laboratorial intercomparisons, was submitted to characterization tests. The performance of these Victoreen ionization chambers showed that they are suitable for use in radioprotection beams, because the results obtained agree with international recommendations. However, these Victoreen ionization chambers can be used in radiotherapy and diagnostic radiology beams only with some considerations, since their performance in these beams, especially in relation to the energy dependence and stabilization time tests, did not agree with the international recommendations for dosimeters used in radiotherapy and diagnostic radiology beams. This work presents data on the performance of several types of ionization chambers in different X-ray beams, that may be useful for choosing the appropriate instrument for measurements in ionizing radiation beams. (author)

  3. Reirradiation Human Spinal Cord Tolerance for Stereotactic Body Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sahgal, Arjun, E-mail: Arjun.sahgal@rmp.uhn.on.ca [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, Princess Margaret Hospital, University of Toronto, Toronto (Canada); Ma, Lijun [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States); Weinberg, Vivian [University of California San Francisco Helen Diller Family Comprehensive Cancer Center Biostatistics Core, San Francisco, CA (United States); Gibbs, Iris C. [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Chao, Sam [Departments of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, OH (United States); Chang, Ung-Kyu [Department of Neurosurgery, Korea Institute of Radiation and Medical Science, Seoul (Korea, Republic of); Werner-Wasik, Maria [Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Angelov, Liliyanna [Departments of Radiation Oncology and Neurosurgery, Cleveland Clinic, Cleveland, OH (United States); Chang, Eric L. [Department of Radiation Oncology, M.D. Anderson Cancer Center, University of Texas, Houston, TX (United States); Sohn, Moon-Jun [Department of Neurosurgery, Inje University, Seoul (Korea, Republic of); Soltys, Scott G. [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Letourneau, Daniel [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto (Canada); Ryu, Sam [Department of Radiation Oncology, Henry Ford Hospital, Detroit, MI (United States); Gerszten, Peter C. [Departments of Neurological Surgery and Radiation Oncology, University of Pittsburgh Medical Center, Pittsburgh, PA (United States); Fowler, Jack [Departments of Human Oncology and Medical Physics, University of Wisconsin, WI (United States); Wong, C. Shun [Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto (Canada); and others

    2012-01-01

    Purpose: We reviewed the treatment for patients with spine metastases who initially received conventional external beam radiation (EBRT) and were reirradiated with 1-5 fractions of stereotactic body radiotherapy (SBRT) who did or did not subsequently develop radiation myelopathy (RM). Methods and Materials: Spinal cord dose-volume histograms (DVHs) for 5 RM patients (5 spinal segments) and 14 no-RM patients (16 spine segments) were based on thecal sac contours at retreatment. Dose to a point within the thecal sac that receives the maximum dose (P{sub max}), and doses to 0.1-, 1.0-, and 2.0-cc volumes within the thecal sac were reviewed. The biologically effective doses (BED) using {alpha}/{beta} = 2 Gy for late spinal cord toxicity were calculated and normalized to a 2-Gy equivalent dose (nBED = Gy{sub 2/2}). Results: The initial conventional radiotherapy nBED ranged from {approx}30 to 50 Gy{sub 2/2} (median {approx}40 Gy{sub 2/2}). The SBRT reirradiation thecal sac mean P{sub max} nBED in the no-RM group was 20.0 Gy{sub 2/2} (95% confidence interval [CI], 10.8-29.2), which was significantly lower than the corresponding 67.4 Gy{sub 2/2} (95% CI, 51.0-83.9) in the RM group. The mean total P{sub max} nBED in the no-RM group was 62.3 Gy{sub 2/2} (95% CI, 50.3-74.3), which was significantly lower than the corresponding 105.8 Gy{sub 2/2} (95% CI, 84.3-127.4) in the RM group. The fraction of the total P{sub max} nBED accounted for by the SBRT P{sub max} nBED for the RM patients ranged from 0.54 to 0.78 and that for the no-RM patients ranged from 0.04 to 0.53. Conclusions: SBRT given at least 5 months after conventional palliative radiotherapy with a reirradiation thecal sac P{sub max} nBED of 20-25 Gy{sub 2/2} appears to be safe provided the total P{sub max} nBED does not exceed approximately 70 Gy{sub 2/2}, and the SBRT thecal sac P{sub max} nBED comprises no more than approximately 50% of the total nBED.

  4. Reirradiation Human Spinal Cord Tolerance for Stereotactic Body Radiotherapy

    International Nuclear Information System (INIS)

    Purpose: We reviewed the treatment for patients with spine metastases who initially received conventional external beam radiation (EBRT) and were reirradiated with 1–5 fractions of stereotactic body radiotherapy (SBRT) who did or did not subsequently develop radiation myelopathy (RM). Methods and Materials: Spinal cord dose–volume histograms (DVHs) for 5 RM patients (5 spinal segments) and 14 no-RM patients (16 spine segments) were based on thecal sac contours at retreatment. Dose to a point within the thecal sac that receives the maximum dose (Pmax), and doses to 0.1-, 1.0-, and 2.0-cc volumes within the thecal sac were reviewed. The biologically effective doses (BED) using α/β = 2 Gy for late spinal cord toxicity were calculated and normalized to a 2-Gy equivalent dose (nBED = Gy2/2). Results: The initial conventional radiotherapy nBED ranged from ∼30 to 50 Gy2/2 (median ∼40 Gy2/2). The SBRT reirradiation thecal sac mean Pmax nBED in the no-RM group was 20.0 Gy2/2 (95% confidence interval [CI], 10.8–29.2), which was significantly lower than the corresponding 67.4 Gy2/2 (95% CI, 51.0–83.9) in the RM group. The mean total Pmax nBED in the no-RM group was 62.3 Gy2/2 (95% CI, 50.3–74.3), which was significantly lower than the corresponding 105.8 Gy2/2 (95% CI, 84.3–127.4) in the RM group. The fraction of the total Pmax nBED accounted for by the SBRT Pmax nBED for the RM patients ranged from 0.54 to 0.78 and that for the no-RM patients ranged from 0.04 to 0.53. Conclusions: SBRT given at least 5 months after conventional palliative radiotherapy with a reirradiation thecal sac Pmax nBED of 20–25 Gy2/2 appears to be safe provided the total Pmax nBED does not exceed approximately 70 Gy2/2, and the SBRT thecal sac Pmax nBED comprises no more than approximately 50% of the total nBED.

  5. Whole-pelvic radiotherapy with spot-scanning proton beams for uterine cervical cancer: a planning study

    Science.gov (United States)

    Hashimoto, Shingo; Shibamoto, Yuta; Iwata, Hiromitsu; Ogino, Hiroyuki; Shibata, Hiroki; Toshito, Toshiyuki; Sugie, Chikao; Mizoe, Jun-etsu

    2016-01-01

    The aim of this study was to compare the dosimetric parameters of whole-pelvic radiotherapy (WPRT) for cervical cancer among plans involving 3D conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), or spot-scanning proton therapy (SSPT). The dose distributions of 3D-CRT-, IMRT-, and SSPT-based WPRT plans were compared in 10 patients with cervical cancer. All of the patients were treated with a prescribed dose of 50.4 Gy in 1.8-Gy daily fractions, and all of the plans involved the same planning target volume (PTV) constrictions. A 3D-CRT plan involving a four-field box, an IMRT plan involving seven coplanar fields, and an SSPT plan involving four fields were created. The median PTV D95% did not differ between the 3D-CRT, IMRT and SSPT plans. The median conformity index 95% and homogeneity index of the IMRT and SSPT were better than those of the 3D-CRT. The homogeneity index of the SSPT was better than that of the IMRT. SSPT resulted in lower median V20 values for the bladder wall, small intestine, colon, bilateral femoral heads, skin, and pelvic bone than IMRT. Comparing the Dmean values, SSPT spared the small intestine, colon, bilateral femoral heads, skin and pelvic bone to a greater extent than the other modalities. SSPT can reduce the irradiated volume of the organs at risk compared with 3D-CRT and IMRT, while maintaining excellent PTV coverage. Further investigations of SSPT are warranted to assess its role in the treatment of cervical cancer. PMID:27380800

  6. The Effect of a Contrast Agent on Proton Beam Range in Radiotherapy Planning Using Computed Tomography for Patients With Locoregionally Advanced Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ui-Jung; Shin, Dong Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Kim, Tae Hyun, E-mail: k2onco@naver.com [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of); Moon, Sung Ho; Lim, Young Kyung; Jeong, Hojin; Rah, Jeong-Eun; Kim, Sang Soo; Kim, Joo-Young; Kim, Dae Yong; Park, Sung Yong; Cho, Kwan Ho [Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Gyeonggi (Korea, Republic of)

    2011-11-15

    Purpose: We evaluated the effect of a contrast agent (CA) on proton beam range in a treatment planning system (TPS) for patients with locoregionally advanced lung cancer. Methods and Materials: Two sets of computed tomography (CT) images (with and without CA) were obtained from 20 patients with lung cancer. Because the increase in Hounsfield unit ( Increment HU) value of the heart and great vessels due to the effect of CA is most prominent among thoracic structures, to evaluate the effect of CA on proton beam range in the TPS, we compared the calculated distal ranges in the plan with CA-enhanced CT with those with corrected CT, in which the HU values of the heart and great vessels in the CA-enhanced CT were replaced by average HU values obtained from the unenhanced CT. Results: The mean Increment HU value and the longest length of the heart and great vessels within the proton beam path in the field that passed through these structures were 189 {+-} 29 HU (range, 110-250 HU) and 7.1 {+-} 1.1 cm (range, 2.6-11.2 cm), respectively. The mean distal range error in the TPS because of the presence of CA was 1.0 {+-} 0.7 cm (range, 0.2-2.6 cm). Conclusion: If CA-enhanced CT images are used for radiotherapy planning using a proton beam for the treatment of lung cancer, our results suggest that the HU values of the heart and great vessels should be replaced by the average HU values of soft tissue to avoid discrepancies between planned and delivered doses.

  7. The Effect of a Contrast Agent on Proton Beam Range in Radiotherapy Planning Using Computed Tomography for Patients With Locoregionally Advanced Lung Cancer

    International Nuclear Information System (INIS)

    Purpose: We evaluated the effect of a contrast agent (CA) on proton beam range in a treatment planning system (TPS) for patients with locoregionally advanced lung cancer. Methods and Materials: Two sets of computed tomography (CT) images (with and without CA) were obtained from 20 patients with lung cancer. Because the increase in Hounsfield unit (∆HU) value of the heart and great vessels due to the effect of CA is most prominent among thoracic structures, to evaluate the effect of CA on proton beam range in the TPS, we compared the calculated distal ranges in the plan with CA-enhanced CT with those with corrected CT, in which the HU values of the heart and great vessels in the CA-enhanced CT were replaced by average HU values obtained from the unenhanced CT. Results: The mean ∆HU value and the longest length of the heart and great vessels within the proton beam path in the field that passed through these structures were 189 ± 29 HU (range, 110–250 HU) and 7.1 ± 1.1 cm (range, 2.6–11.2 cm), respectively. The mean distal range error in the TPS because of the presence of CA was 1.0 ± 0.7 cm (range, 0.2–2.6 cm). Conclusion: If CA-enhanced CT images are used for radiotherapy planning using a proton beam for the treatment of lung cancer, our results suggest that the HU values of the heart and great vessels should be replaced by the average HU values of soft tissue to avoid discrepancies between planned and delivered doses.

  8. Comparison of localization performance with implanted fiducial markers and cone-beam computed tomography for on-line image-guided radiotherapy of the prostate

    International Nuclear Information System (INIS)

    Purpose: The aim of this work was to assess the accuracy of kilovoltage (kV) cone-beam computed tomography (CBCT)-based setup corrections as compared with orthogonal megavoltage (MV) portal image-based corrections for patients undergoing external-beam radiotherapy of the prostate. Methods and Materials: Daily cone-beam CT volumetric images were acquired after setup for patients with three intraprostatic fiducial markers. The estimated couch shifts were compared retrospectively to patient adjustments based on two orthogonal MV portal images (the current clinical standard of care in our institution). The CBCT soft-tissue based shifts were also estimated by digitally removing the gold markers in each projection to suppress the artifacts in the reconstructed volumes. A total of 256 volumetric images for 15 patients were analyzed. Results: The Pearson coefficient of correlation for the patient position shifts using fiducial markers in MV vs. kV was (R2 = 0.95, 0.84, 0.81) in the left-right (LR), anterior-posterior (AP), and superior-inferior (SI) directions, respectively. The correlation using soft-tissue matching was as follows: R2 = 0.90, 0.49, 0.51 in the LR, AP and SI directions. A Bland-Altman analysis showed no significant trends in the data. The percentage of shifts within a ±3-mm tolerance (the clinical action level) was 99.7%, 95.5%, 91.3% for fiducial marker matching and 99.5%, 70.3%, 78.4% for soft-tissue matching. Conclusions: Cone-beam CT is an accurate and precise tool for image guidance. It provides an equivalent means of patient setup correction for prostate patients with implanted gold fiducial markers. Use of the additional information provided by the visualization of soft-tissue structures is an active area of research

  9. Prognostic significance of several histological features in intermediate and high-risk endometrial cancer patients treated with curative intent using surgery and adjuvant radiotherapy

    International Nuclear Information System (INIS)

    Full text: The purpose of the present study was to explore the prognostic significance of several histological features with respect to lymph node metastasis, failure-free survival (FeS), and overall survival (Os) in intermediate and high-risk endometrial cancer patients treated with curative intent. One hundred and eighty patients with endometrial cancer were treated with hysterectomy with or without lymphadenectomy and received external beam radiotherapy (EBRT). The mean follow-up period was 4.25 years (range 0.44-10.45 years). In multifactor analysis, fractional myometrial invasion (MI) (P = 0.047), histology (P < 0.001) and lymph-vascular space invasion (LVSI) (P = 0.025) were significant predictors for FFS when nodal status was not included. When lymph node status was known, histology (P - 0.007) and LVSI (P = 0.014) remained significant factors for FFS. For OS, histology (P < 0.001) and fractional MI (P = 0.004) were the significant factors. Lymph node status could be predicted by tumour grading (P = 0.016) and absolute MI (P 0.002). Histology type and the presence of LVSI were the most important prognostic factors in high-risk endometrial cancer patients treated by surgery and postoperative radiotherapy. Absolute MI and tumour grading were useful predictors of nodal spread.

  10. Experimental method of in-vivo dosimetry without build-up device on the skin for external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Hosang [Department of Radiation Oncology, Pusan National University Yangsan Hospital, Yangsan (Korea, Republic of); Medical Research Institute, Pusan National University Hospital, Busan (Korea, Republic of); Nam, Jiho; Lee, Jayoung [Department of Radiation Oncology, Pusan National University Yangsan Hospital, Yangsan (Korea, Republic of); Park, Dahl, E-mail: dpark411@gmail.com [Department of Radiation Oncology, Pusan National University Hospital, Busan (Korea, Republic of); Baek, Cheol-Ha [Department of Radiological Science, Dongseo University, Busan (Korea, Republic of); Kim, Wontaek; Ki, Yongkan; Kim, Dongwon [Department of Radiation Oncology, Pusan National University Hospital, Busan (Korea, Republic of)

    2015-06-01

    Accurate dose delivery is crucial to the success of modern radiotherapy. To evaluate the dose actually delivered to patients, in-vivo dosimetry (IVD) is generally performed during radiotherapy to measure the entrance doses. In IVD, a build-up device should be placed on top of an in-vivo dosimeter to satisfy the electron equilibrium condition. However, a build-up device made of tissue-equivalent material or metal may perturb dose delivery to a patient, and requires an additional laborious and time-consuming process. We developed a novel IVD method using a look-up table of conversion ratios instead of a build-up device. We validated this method through a monte-carlo simulation and 31 clinical trials. The mean error of clinical IVD is 3.17% (standard deviation: 2.58%), which is comparable to that of conventional IVD methods. Moreover, the required time was greatly reduced so that the efficiency of IVD could be improved for both patients and therapists.

  11. Long-term effect of external beam radiotherapy of optic disc hemangioma in a patient with von hippel-lindau disease

    Directory of Open Access Journals (Sweden)

    Matsuo,Toshihiko

    2011-04-01

    Full Text Available An 18-year-old woman with a 2-year history of hypertension and headache was diagnosed with noradrenalin-secreting bilateral adrenal pheochromocytomas with paragangliomas in the background of von Hippel-Lindau disease with family histories and a missense mutation, 712C to T (Arg167Trp in the VHL gene. She had optic disc hemangioma in the left eye which gradually enlarged and caused serous retinal detachment on the macula in one year. Low-dose external beam radiation (20 Gy was administered to the left eye using a lens-sparing single lateral technique. She underwent craniotomy for cerebellar hemangioblastoma at the age of 22 years and total pancreatectomy for multiple neuroendocrine tumors at the age of 24 years. In the 6-year follow-up period after the radiotherapy, the optic disc hemangioma gradually reduced in size and its activity remained low, allowing good central vision to be maintained. External beam radiation is recommended as a treatment option for the initial therapy for optic disc hemangioma.

  12. Application of megavoltage cone-beam computed tomography in radiotherapy%兆伏锥形束CT在放疗中的应用

    Institute of Scientific and Technical Information of China (English)

    高云生; 胡伟刚; 胡超苏

    2008-01-01

    兆伏锥形束CT(MVCBCT)在体内有金属移植物时可以消除金属对散射线的影响,提高图像质量,便于勾画靶区,纠正摆位误差,并且可以监测治疗期间患者解剖结构的变化.通过放射治疗过程中的MVCBCT图像进行剂量监测和计算,可了解肿瘤退缩、患者体重减轻等对靶区和正常组织所受剂量的影响,更为重要的是可在其图像上进行图像引导放射治疗的研究.%Megavoltage cone-beam computed tomography can eliminate the impact of metal scattering to improve imaging quality, and help to contour targets and organs-at-risk, correct positioning errors and monitor the anatomical structure changes of patients in treatment room. During the course of treatment, megavohage cone-beam CT image can monitor the variation of dose distribution that results from tumor shrinkage, weight loss, etc. More importantly, the images can be applied to image-guided radiotherapy research.

  13. A retrospective study of external beam radiation, neutron brachytherapy, and concurrent chemotherapy for patients with localized advanced carcinoma of the esophagus

    International Nuclear Information System (INIS)

    The aim of this study was to retrospectively observe and analyze the long-term treatment outcomes of a total of 140 esophageal cancer patients who were treated with californium-252 (252Cf) neutron brachytherapy (NBT) in combination with external beam radiotherapy (EBRT) and concurrent chemotherapy (CCT). From January 2002 to November 2012, 140 patients with esophageal cancer underwent NBT in combination with EBRT and CCT. The distribution of the patient numbers over the various cancer stages of IIA, IIB, and III were 43, 7, and 90, respectively. The total radiation dose to the reference point via NBT was 8–25 Gy-eq in two to five fractions with one fraction per week. The total dose via EBRT was 50–60 Gy, which was delivered over a period of five to six weeks with normal fractionation. Fifty-four and 86 patients received tegafur suppositories (TS) and continuous infusion of fluorouracil (5-Fu) with cisplatin (CDDP), respectively. The median follow-up time was 42 months. The minimum follow-up was three months, and the maximum was 106 months. The overall median survival including death from all causes was 29.5 months. The five-year overall survival rate (OS) and local control (LC) were 33.4% and 55.9%, respectively. The chemotherapy regimen was a factor that was significantly associated with OS (p = 0.025) according to univariate analysis. The five-year OSs were 27.4% and 44.3% for the PF and TS chemotherapy regimens, respectively. Regarding acute toxicity, no incidences of fistula or massive bleeding were observed during this treatment period. The incidence of severe, late complications was related to the PF chemotherapy regimen (p = 0.080). The clinical data indicated that NBT in combination with EBRT and CRT produced favorable local control and long-term survival rates for patients with esophageal cancer and that the side effects were tolerable. A reasonable CRT regimen can decrease the rate of severe, late complications

  14. Technical Note: Suppression of artifacts arising from simultaneous cone-beam imaging and RF transponder tracking in prostate radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Poludniowski, Gavin; Webb, Steve; Evans, Philip M. [Joint Department of Physics, Division of Radiotherapy and Imaging, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2 5PT (United Kingdom)

    2012-03-15

    Purpose: Artifacts in treatment-room cone-beam reconstructions have been observed at the authors' center when cone-beam acquisition is simultaneous with radio frequency (RF) transponder tracking using the Calypso 4D system (Calypso Medical, Seattle, WA). These artifacts manifest as CT-number modulations and increased CT-noise. The authors present a method for the suppression of the artifacts. Methods: The authors propose a three-stage postprocessing technique that can be applied to image volumes previously reconstructed by a cone-beam system. The stages are (1) segmentation of voxels into air, soft-tissue, and bone; (2) application of a 2D spatial-filter in the axial plane to the soft-tissue voxels; and (3) normalization to remove streaking along the axial-direction. The algorithm was tested on patient data acquired with Synergy XVI cone-beam CT systems (Elekta, Crawley, United Kingdom). Results: The computational demands of the suggested correction are small, taking less than 15 s per cone-beam reconstruction on a desktop PC. For a moderate loss of spatial-resolution, the artifacts are strongly suppressed and low-contrast visibility is improved. Conclusions: The correction technique proposed is fast and effective in removing the artifacts caused by simultaneous cone-beam imaging and RF-transponder tracking.

  15. A case study comparing the relative benefit of optimizing beam weights, wedge angles, beam orientations and tomotherapy in stereotactic radiotherapy of the brain

    Science.gov (United States)

    Oldham, M.; Khoo, V. S.; Rowbottom, C. G.; Bedford, J. L.; Webb, S.

    1998-08-01

    A treatment-planning case study has been performed on a patient with a medium-sized, convex brain tumour. The study involved the application of advanced treatment-plan optimization techniques to improve on the dose distribution of the `standard plan' used to treat the patient. The standard plan was created according to conventional protocol at the Royal Marsden NHS Trust, and consisted of a three-field (one open and two wedged) non-coplanar arrangement, with field shaping to the beam's-eye view of the planning target volume (PTV). Three optimized treatment plans were created corresponding to (i) the optimization of the beam weights and wedge angles of the standard plan, (ii) the optimization of the beam orientations, beam weights and wedge angles of the standard plan, and (iii) a full fluence tomotherapy optimization of 1 cm wide (at isocentre), 43/8/010/img8.gif" ALIGN="MIDDLE"/> arcs. (i) and (ii) were created on the VOXELPLAN research 3D treatment-planning system, using in-house developed optimization algorithms, and (iii) was created on the PEACOCK tomotherapy planning system. The downhill-simplex optimization algorithm is used, in conjuction with `threshold-dose' cost-function terms enabling the algorithm to optimize specific regions of the dose-volume histogram (DVH) curve. The `beam-cost plot' tool is presented as a visual aid to the selection of beneficial beam directions. The methods and pitfalls in the transfer of plans and patient data between the two planning systems are discussed. Each optimization approach was evaluated, relative to the standard plan, on the basis of DVH and dose statistics in the PTV and organs at risk (OARs). All three optimization approaches were able to improve on the dose distribution of the standard plan. The magnitude of the improvement was greater for the optimized beam-orientation and tomotherapy plans (up to 15% and 30% for the maximum and mean OAR doses). A smaller improvement was observed in the beam-weight and wedge

  16. Lack of benefit for the addition of androgen deprivation therapy to dose-escalated radiotherapy in the treatment of intermediate- and high-risk prostate cancer.

    LENUS (Irish Health Repository)

    Krauss, Daniel

    2012-02-01

    PURPOSE: Assessment of androgen deprivation therapy (ADT) benefits for prostate cancer treated with dose-escalated radiotherapy (RT). METHODS AND MATERIALS: From 1991 to 2004, 1,044 patients with intermediate- (n = 782) or high-risk (n = 262) prostate cancer were treated with dose-escalated RT at William Beaumont Hospital. Patients received external-beam RT (EBRT) alone, brachytherapy (high or low dose rate), or high dose rate brachytherapy plus pelvic EBRT. Intermediate-risk patients had Gleason score 7, prostate-specific antigen (PSA) 10.0-19.9 ng\\/mL, or Stage T2b-T2c. High-risk patients had Gleason score 8-10, PSA >\\/=20, or Stage T3. Patients were additionally divided specifically by Gleason score, presence of palpable disease, and PSA level to further define subgroups benefitting from ADT. RESULTS: Median follow-up was 5 years; 420 patients received ADT + dose-escalated RT, and 624 received dose-escalated RT alone. For all patients, no advantages in any clinical endpoints at 8 years were associated with ADT administration. No differences in any endpoints were associated with ADT administration based on intermediate- vs. high-risk group or RT modality when analyzed separately. Patients with palpable disease plus Gleason >\\/=8 demonstrated improved clinical failure rates and a trend toward improved survival with ADT. Intermediate-risk patients treated with brachytherapy alone had improved biochemical control when ADT was given. CONCLUSION: Benefits of ADT in the setting of dose-escalated RT remain poorly defined. This question must continue to be addressed in prospective study.

  17. Whole brain radiotherapy with a conformational external beam radiation boost for lung cancer patients with 1-3 brain metastasis: a multi institutional study

    International Nuclear Information System (INIS)

    To determine the outcome of patients with brain metastasis (BM) from lung cancer treated with an external beam radiotherapy boost (RTB) after whole brain radiotherapy (WBRT). A total of 53 BM patients with lung cancer were treated sequentially with WBRT and RTB between 1996 and 2008 according to our institutional protocol. Mean age was 58.8 years. The median KPS was 90. Median recursive partitioning analysis (RPA) and graded prognostic assessment (GPA) grouping were 2 and 2.5, respectively. Surgery was performed on 38 (71%) patients. The median number of BM was 1 (range, 1-3). Median WBRT and RTB combined dose was 39 Gy (range, 37.5 - 54). Median follow-up was 12.0 months. During the period of follow-up, 37 (70%) patients died. The median overall survival (OS) was 14.5 months. Only 13 patients failed in the brain. The majority of patients (n = 29) failed distantly. The 1-year OS, -local control, extracranial failure rates were 61.2%, 75.2% and 60.8%, respectively. On univariate analysis, improved OS was found to be significantly associated with total dose (≤ 39 Gy vs. > 39 Gy; p < 0.01), age < 65 (p < 0.01), absence of extracranial metastasis (p < 0.01), GPA ≥ 2.5 (p = 0.01), KPS ≥ 90 (p = 0.01), and RPA < 2 (p = 0.04). On multivariate analysis, total dose (p < 0.01) and the absence of extracranial metastasis (p = 0.03) retained statistical significance. The majority of lung cancer patients treated with WBRT and RTB progressed extracranially. There might be a subgroup of younger patients with good performance status and no extracranial disease who may benefit from dose escalation after WBRT to the metastatic site

  18. The clinical feasibility and performance of an orthogonal X-ray imaging system for image-guided radiotherapy in nasopharyngeal cancer patients: Comparison with cone-beam CT.

    Science.gov (United States)

    Zhao, Li-Rong; Zhou, Yi-Bing; Li, Guang-Hui; Li, Qi-Ming; Yang, Ding-Qiang; Li, Han-Xu; Wan, Jiu-Qing; Sun, Jian-Guo

    2016-01-01

    The demand for greater accuracy of intensity-modulated radiotherapy (IMRT) has driven the development of more advanced verification systems for image-guided radiotherapy (IGRT). The purpose of this study is to investigate setup discrepancies measured between an orthogonal X-ray guidance system (XGS-10) and cone-beam computed tomography (CBCT) of Varian in the IMRT of patients with nasopharyngeal cancer (NPC). The setup errors measured by XGS-10 and CBCT at the treatment unit with respect to the planning CTs were recorded for 30 patients with NPC. The differences in residual setup errors between XGS-10 system and CBCT were computed and quantitatively analyzed. The time of image acquisition and image registration was recorded. The radiation doses delivered by CBCT and XGS-10 were measured using PTW0.6CC ionization chambers and a water phantom. The differences between setup errors measured by the XGS-10 system and CBCT were generally <1.5 mm for translations, indicating a reasonably good agreement between the two systems for patients with NPC in the translation directions of A-P (P = 0.856), L-R (P = 0.856) and S-I (P = 0.765). Moreover, compared with CBCT, XGS-10 took much shorter image acquisition and registration time (P <0.001) and delivered only a small fraction of extra radiation dose to the patients (P <0.001). These results indicate that XGS-10 offers high localization accuracy similar to CBCT and additional benefits including prompt imaging process, low imaging radiation exposure, real time monitoring, which therefore represents a potential attractive alternative to CBCT for clinical use. PMID:26703446

  19. Radiation recall dermatitis after Docetaxel administration and external beam radiotherapy. Report of two cases and review of literature

    International Nuclear Information System (INIS)

    Radiation recall refers to a tissue reaction produced by a chemotherapeutic agent in a previously irradiated field that would not occur in a nonirradiated field. Docetaxel is a member of the taxane group of antineoplastic agents that cause disruption of cell division by enhancing microtubule assembly and inhibiting tubulin depolymerization. As well as in breast cancer and lung cancer treatment, its association in a chemo-radiation planned treatment becomes frequent and effective. Most of radiation recall dermatitis (RDD) reported in literature concerned Paclitaxel or other drugs. We report two particularly striking cases of RDD with Docetaxel and radiotherapy. Even if etiology remains undetermined, a number of hypotheses can be formulated. Familiarity with this phenomenon and potential complications of chemotherapy following tumor irradiation may expedite early diagnosis and appropriate life saving treatment. (authors)

  20. Dosimetric effect of intrafraction motion and residual setup error for hypofractionated prostate intensity-modulated radiotherapy with online cone beam computed tomography image guidance.

    LENUS (Irish Health Repository)

    Adamson, Justus

    2012-02-01

    PURPOSE: To quantify the dosimetric effect and margins required to account for prostate intrafractional translation and residual setup error in a cone beam computed tomography (CBCT)-guided hypofractionated radiotherapy protocol. METHODS AND MATERIALS: Prostate position after online correction was measured during dose delivery using simultaneous kV fluoroscopy and posttreatment CBCT in 572 fractions to 30 patients. We reconstructed the dose distribution to the clinical tumor volume (CTV) using a convolution of the static dose with a probability density function (PDF) based on the kV fluoroscopy, and we calculated the minimum dose received by 99% of the CTV (D(99)). We compared reconstructed doses when the convolution was performed per beam, per patient, and when the PDF was created using posttreatment CBCT. We determined the minimum axis-specific margins to limit CTV D(99) reduction to 1%. RESULTS: For 3-mm margins, D(99) reduction was <\\/=5% for 29\\/30 patients. Using post-CBCT rather than localizations at treatment delivery exaggerated dosimetric effects by ~47%, while there was no such bias between the dose convolved with a beam-specific and patient-specific PDF. After eight fractions, final cumulative D(99) could be predicted with a root mean square error of <1%. For 90% of patients, the required margins were <\\/=2, 4, and 3 mm, with 70%, 40%, and 33% of patients requiring no right-left (RL), anteroposterior (AP), and superoinferior margins, respectively. CONCLUSIONS: For protocols with CBCT guidance, RL, AP, and SI margins of 2, 4, and 3 mm are sufficient to account for translational errors; however, the large variation in patient-specific margins suggests that adaptive management may be beneficial.

  1. Monte Carlo Simulation of Electron Beams for Radiotherapy - EGS4, MCNP4b and GEANT3 Intercomparison

    CERN Document Server

    Trindade, A; Alves, C M; Chaves, A; Lopes, C; Oliveira, C; Peralta, L

    2000-01-01

    In medical radiation physics, an increasing number of Monte Carlo codes are being used, which requires intercomparison between them to evaluated the accuracy of the simulated results against benchmark experiments. The Monte Carlo code EGS4, commonly used to simulate electron beams from medical linear accelerators, was compared with GEANT3 and MCNP4b. Intercomparison of electron energy spectra, angular and spatial distribution were carried out for the Siemens KD2 linear accelerator, at beam energies of 10 and 15 MeV for a field size of 10x10 cm2. Indirect validation was performed against electron depth doses curves and beam profiles measured in a MP3-PTW water phantom using a Markus planar chamber. Monte Carlo isodose lines were reconstructed and compared to those from commercial treatment planning systems (TPS's) and with experimental data.

  2. Effect of the normalized prescription isodose line on the magnitude of Monte Carlo vs. pencil beam target dose differences for lung stereotactic body radiotherapy.

    Science.gov (United States)

    Zheng, Dandan; Zhang, Qinghui; Liang, Xiaoying; Zhu, Xiaofeng; Verma, Vivek; Wang, Shuo; Zhou, Sumin

    2016-07-08

    In lung stereotactic body radiotherapy (SBRT) cases, the pencil beam (PB) dose calculation algorithm is known to overestimate target dose as compared to the more accurate Monte Carlo (MC) algorithm. We investigated whether changing the normalized prescription isodose line affected the magnitude of MC vs. PB target dose differences. Forty-eight patient plans and twenty virtual-tumor phantom plans were studied. For patient plans, four alternative plans prescribed to 60%, 70%, 80%, and 90% isodose lines were each created for 12 patients who previously received lung SBRT treatments. Using 6 MV dynamic conformal arcs, the plans were individually optimized to achieve similar dose coverage and conformity for all plans of the same patient, albeit at the different prescription levels. These plans, having used a PB algorithm, were all recalculated with MC to compare the target dose differences. The relative MC vs. PB target dose variations were investigated by comparing PTV D95, Dmean, and D5 loss at the four prescription levels. The MC-to-PB ratio of the plan heterogeneity index (HI) was also evaluated and compared among different isodose levels. To definitively demonstrate the cause of the isodose line dependence, a simulated phantom study was conducted using simple, spherical virtual tumors planned with uniform block margins. The tumor size and beam energy were also altered in the phantom study to investigate the interplay between these confounding factors and the isodose line effect. The magnitude of the target dose overestimation by PB was greater for higher prescription isodose levels. The MC vs. PB reduction in the target dose coverage indices, D95 and V100 of PTV, were found to monotonically increase with increasing isodose lines from 60% to 90%, resulting in more pronounced target dose coverage deficiency at higher isodose prescription levels. No isodose level-dependent trend was observed for the dose errors in the target mean or high dose indices, Dmean or D5. The

  3. WE-G-BRE-06: New Potential for Enhancing External Beam Radiotherapy for Lung Cancer Using FDA-Approved Concentrations of Cisplatin Or Carboplatin Nanoparticles Administered Via Inhalation

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Y; Altundal, Y; Sajo, E [University Massachusetts Lowell, Lowell, MA (United States); Detappe, A [Brigham ' Woman' s Hospital, Boston, MA (United States); Dana Farber Cancer Institute, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); University of Lyon, Lyon (France); Makrigiorgos, G; Berbeco, R [Brigham ' Woman' s Hospital, Boston, MA (United States); Dana Farber Cancer Institute, Boston, MA (United States); Harvard Medical School, Boston, MA (United States); Ngwa, W [University Massachusetts Lowell, Lowell, MA (United States); Brigham ' Woman' s Hospital, Boston, MA (United States); Dana Farber Cancer Institute, Boston, MA (United States); Harvard Medical School, Boston, MA (United States)

    2014-06-15

    Purpose: This study investigates, for the first time, the dose enhancement to lung tumors due to cisplatin nanoparticles (CNPs) and carboplatin nanoparticles (CBNPs) administered via inhalation route (IR) during external beam radiotherapy. Methods: Using Monte Carlo generated 6 MV energy fluence spectra, a previously employed analytic method was used to estimate dose enhancement to lung tumor due to radiation-induced photoelectrons from CNPs administered via IR in comparison to intravenous (IV) administration. Previous studies have indicated about 5% of FDA-approved cisplatin concentrations reach the lung tumor via IV. Meanwhile recent experimental studies indicate that 3.5–14.6 times higher concentrations of CNPs can reach the lung tumors by IR compared to IV. Taking these into account, the dose enhancement factor (DEF) defined as the ratio of the dose with and without CNPs was calculated for field size of 10 cm × 10 cm (sweeping gap), for a range of tumor depths and tumor sizes. Similar calculations were done for CBNPs. Results: For IR with 3.5 times higher concentrations than IV, and 2 cm diameter tumor, clinically significant DEF values of 1.19–1.30 were obtained for CNPs at 3–10 cm depth, respectively, in comparison to 1.06–1.09 for IV. For CBNPs, DEF values of 1.26–1.41 were obtained in comparison to 1.07–1.12 for IV. For IR with 14.6 times higher concentrations, higher DEF values were obtained e.g. 1.81–2.27 for CNPs. DEF increased with increasing field size or decreasing tumor size. Conclusions: Our preliminary results indicate that major dose enhancement to lung tumors can be achieved using CNPs/CBNPs administered via IR, in contrast to IV administration during external beam radiotherapy. These findings highlight a potential new approach for radiation boosting to lung tumors using CNPs/CBNPs administered via IR. This would, especially, be applicable during concomitant chemoradiotherapy, potentially allowing for dose enhancement while

  4. Real-time optical-fibre luminescence dosimetry for radiotherapy: physical characteristics and applications in photon beams

    DEFF Research Database (Denmark)

    Aznar, M.C.; Andersen, C.E.; Bøtter-Jensen, L.;

    2004-01-01

    A new optical-fibre radiation dosimeter system, based on radioluminescence and optically stimulated luminescence from carbon-doped aluminium oxide, was developed and tested in clinical photon beams. This prototype offers several features, such as a small detector (1 x 1 x 2 mm), high sensitivity...

  5. Prospective Multi-Institutional Study of Definitive Radiotherapy With High-Dose-Rate Intracavitary Brachytherapy in Patients With Nonbulky (<4-cm) Stage I and II Uterine Cervical Cancer (JAROG0401/JROSG04-2)

    Energy Technology Data Exchange (ETDEWEB)

    Toita, Takafumi, E-mail: b983255@med.u-ryukyu.ac.jp [Department of Radiology, Graduate School of Medical Science, University of Ryukyus, Okinawa (Japan); Kato, Shingo [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Niibe, Yuzuru [Department of Radiology, School of Medicine, Kitasato University, Sagamihara (Japan); Ohno, Tatsuya [Gunma University Heavy Ion Medical Center, Maebashi (Japan); Kazumoto, Tomoko [Department of Radiology, Saitama Cancer Center, Saitama (Japan); Kodaira, Takeshi [Department of Radiation Oncology, Aichi Cancer Center, Nagoya (Japan); Kataoka, Masaaki [Department of Radiology, National Shikoku Cancer Center, Ehime (Japan); Shikama, Naoto [Department of Radiation Oncology, Saku Central Hospital, Saku (Japan); Kenjo, Masahiro [Department of Radiation Oncology, Graduate School of Medical Science, Hiroshima University, Hiroshima (Japan); Tokumaru, Sunao [Department of Radiology, Saga University, Saga (Japan); Yamauchi, Chikako [Department of Radiation Oncology, Shiga Medical Center for Adults, Moriyama (Japan); Suzuki, Osamu [Department of Radiation Oncology, Osaka Medical Center for Cancer, Osaka (Japan); Sakurai, Hideyuki [Proton Medical Research Center and Tsukuba University, Tsukuba (Japan); Numasaki, Hodaka; Teshima, Teruki [Department of Medical Physics and Engineering, Graduate School of Medicine, Osaka University, Suita, Osaka (Japan); Oguchi, Masahiko [Department of Radiation Oncology, Cancer Institute Hospital, Tokyo (Japan); Kagami, Yoshikazu [Radiation Oncology Division, National Cancer Center Hospital, Tokyo (Japan); Nakano, Takashi [Department of Radiation Oncology, Gunma University, Graduate School of Medicine, Maebashi (Japan); Hiraoka, Masahiro [Department of Radiation Oncology and Image-applied Therapy, Kyoto University, Graduate School of Medicine, Kyoto (Japan); Mitsuhashi, Norio [Department of Radiation Oncology, Tokyo Women' s Medical University, Tokyo (Japan)

    2012-01-01

    Purpose: To determine the efficacy of a definitive radiotherapy protocol using high-dose-rate intracavitary brachytherapy (HDR-ICBT) with a low cumulative dose schedule in nonbulky early-stage cervical cancer patients, we conducted a prospective multi-institutional study. Methods and Materials: Eligible patients had squamous cell carcinoma of the intact uterine cervix, Federation of Gynecologic Oncology and Obstetrics (FIGO) stages Ib1, IIa, and IIb, tumor size <40 mm in diameter (assessed by T2-weighted magnetic resonance imaging), and no pelvic/para-aortic lymphadenopathy. The treatment protocol consisted of whole-pelvis external beam radiotherapy (EBRT) of 20 Gy/10 fractions, pelvic EBRT with midline block of 30 Gy/15 fractions, and HDR-ICBT of 24 Gy/4 fractions (at point A). The cumulative biologically effective dose (BED) was 62 Gy{sub 10} ({alpha}/{beta} = 10) at point A. The primary endpoint was the 2-year pelvic disease progression-free (PDPF) rate. All patients received a radiotherapy quality assurance review. Results: Between September 2004 and July 2007, 60 eligible patients were enrolled. Thirty-six patients were assessed with FIGO stage Ib1; 12 patients with stage IIa; and 12 patients with stage IIb. Median tumor diameter was 28 mm (range, 6-39 mm). Median overall treatment time was 43 days. Median follow-up was 49 months (range, 7-72 months). Seven patients developed recurrences: 3 patients had pelvic recurrences (2 central, 1 nodal), and 4 patients had distant metastases. The 2-year PDPF was 96% (95% confidence interval [CI], 92%-100%). The 2-year disease-free and overall survival rates were 90% (95% CI, 82%-98%) and 95% (95% CI, 89%-100%), respectively. The 2-year late complication rates (according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer of Grade {>=}1) were 18% (95% CI, 8%-28%) for large intestine/rectum, 4% (95% CI, 0%-8%) for small intestine, and 0% for bladder. No Grade {>=}3 cases were

  6. Evaluating uncertainties in the cross-calibration of parallel ion chambers used in electron beam radiotherapy; Avaliacao das incertezas no processo de calibracao cruzada de camaras de placas paralelas utilizadas em feixes de eletrons para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Ernani; Travassos, Paulo; Ferreira, Max da Silva; Carvalho, Samira Marques de; Silva, Michele Maria da; Peixoto, Jose Guilherme Pereira, E-mail: ernanianderson@hotmail.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Salmon Junior, Helio Augusto [Grupo COI - Clinicas Oncologicas, Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This study aims to estimative the combined standard uncertainty for a detector parallel plate used for dosimetry of electron beams in linear accelerators for radiotherapy, which has been calibrated by the cross-calibration method. Keeping the combined standard uncertainty next of the uncertainty informed in the calibration certificate of the reference chamber, become possible establish the calibration factor of the detector. The combined standard uncertainty obtained in this study was 2.5 %. (author)

  7. Analyse of setup errors and margin for thoracic carcinoma radiotherapy with cone-beam CT-based image guidance

    International Nuclear Information System (INIS)

    Objective: To study the role of KV CBCT on the geometrical accuracy of three dimensional conformal radiotherapy (3DCRT) and to evaluate the margin of targets and peripheral OAR for thoracic carcinoma. Methods: 34 patients with thoracic carcinoma were enrolled.Varian-IX lilac with OBI system was used to acquire CBCT scans before delivery in 3DCRT. The left-right (x), superior-inferior (y), anterior-posterior (z) setup errors of patients can be obtained from the tomography images automatically restructured by the system. Results: According to 279 CBCT scans the systemic ± random error on x, y, z directions were (-0.16 ± 3.25) mm, (-1.36 ± 5.43) mm, (-2.43 ± 2.14) mm and (2.41 ± 2.18) mm, (4.27 ± 3.60) mm, (2.71 ± 1.77) mm respectively if we do not consider the direction of setup errors. The margins of targets were calculated as 2.68 mm, 7.19 mm and 7.57 mm respectively. Conclusions: Setup errors are unavoidable in thoracic carcinoma irradiation. We suggest a PTV margin of 2.68 mm, 7.19 mm and 7.57 mm in the left-right, superior-inferior and anterior-posterior directions respectively in our department. (authors)

  8. Healing of late endoscopic changes in the rectum between 12 and 65 months after external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Goldner, Gregor; Poetter, Richard; Kranz, Alexander; Bluhm, Alexandra [Universitaetsklinikum Vienna (Austria). Dept. of Radiotherapy and Radiobiology; Doerr, Wolfgang [Universitaetsklinikum Vienna (Austria). Dept. of Radiotherapy and Radiobiology; Technische Univ. Dresden (Germany). Dept. of Radiotherapy and Radiation Oncology

    2011-03-15

    Purpose: To evaluate the time course of late rectal mucosal changes after prostate cancer radiotherapy (RT). Patients and Methods: A rectosigmoidoscopy was performed at 12, 24, and 65 months after RT in 20 patients. Rectal mucosal changes (telangiectasia, congested mucosa, ulceration, stricture, and necrosis) were scored and documented according to the Vienna Rectoscopy Score (VRS, score 0-3). Results: VRS of 0 and 3, were found in 20% of patients (n = 4) and 5% of patients (n = 1), respectively at all time points. A shift of the VRS from 2 to 1 was found with incidence rates of 60% at 12 months and 20% at 65 months, which is equivalent to an improvement rate of 67%. Laser coagulation was required in 3 patients (15%) with rectal bleeding due to telangiectasia grade {>=}2. Conclusion: Late rectal mucosal changes are frequent after pelvic RT. Generally only the incidence rates corresponding to the initial diagnosis of the complications, independent of subsequent recovery, are reported. The results reported in the present study show that complications often improve over time. Hence, the usual reports of complication rates overestimate the proportion of patients presenting with side effects of certain grades. (orig.)

  9. Radiotherapy dose calculation on KV cone-beam CT image for lung tumor using the CIRS calibration

    OpenAIRE

    Ma, ChangSheng; Cao, Jianping; Yin, Yong; Zhu, Jian

    2014-01-01

    On-board kilovoltage (KV) cone-beam computed tomography (CBCT) images are used predominantly for the setup of patients' positioning. The image data can also potentially be used for dose calculation with the precise calibration of Hounsfield units (HU) to electron density (HU-density). CBCT calibration was analyzed in this study. A clinical treatment planning system was employed for CT and KV CBCT image to dose calculations and subsequent comparisons. Two HU-density tables were generated using...

  10. Computer simulation dose studies in heterogeneous media for electron and proton beam radiotherapy of static and moving targets

    Science.gov (United States)

    Lee, Tae Kyu

    The energy-dependent electron loss model (ELM) and proton loss model (PLM) have been developed to predict dose deposition in heterogeneous slab media. Predictions of dose deposition in heterogeneous slab media are compared to the Monte Carlo calculations and experimental measurements. Slab media studied comprised water/bone/water and water/lung/water and incident beam energies between 10MeV and 18MeV for electron beams and 100MeV and 160MeV for proton beams. Dose discrepancies at large depths beyond the interface were within 5% of maximum dose. This error may be attributed to the assumption of a Gaussian energy distribution for the charge particles at depth. The computational cost is low compared to Monte Carlo simulations making the ELM and PLM attractive as a fast dose engine for dose optimization algorithms. To simulate a more realistic and challenging clinical treatment, a mathematical 3-D phantom was defined to simulate inferior-superior motion of a lung tumor target. Lung size and density change during the breathing cycle was modeled from full inspiration to full expiration. Sensitivity to dose error due to the respiratory motion of the target and the right lung, defined as the organ at risk (OAR), was studied for intensity modulated proton therapy (IMPT) and intensity modulated x-ray therapy (IMXT). Effects of rotational or lateral setup error on the dose distribution were studied independently and simultaneously with breathing.

  11. Accelerated partial breast irradiation with external beam three-dimensional conformal radiotherapy. Five-year results of a prospective phase II clinical study

    Energy Technology Data Exchange (ETDEWEB)

    Mozsa, Emoeke [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Landesklinikum Wiener Neustadt, Department of Radiooncology and Radiotherapy, Wiener Neustadt (Austria); Meszaros, Norbert; Major, Tibor; Froehlich, Georgina; Stelczer, Gabor; Fodor, Janos; Polgar, Csaba [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Sulyok, Zoltan [National Institute of Oncology, Centre of Surgery, Budapest (Hungary)

    2014-05-15

    The aim of this study was to report the 5-year results of accelerated partial breast irradiation (APBI) using external beam three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2011, 44 patients with low-risk, stage I-II breast cancer underwent breast-conserving surgery. Postoperative APBI was given by means of 3D-CRT using three to five non-coplanar fields. The total dose of APBI was 36.9 Gy (nine fractions of 4.1 Gy b.i.d.). The mean follow-up time was 58.2 months for surviving patients. Survival results, side effects, and cosmetic results were assessed. One (2.3 %) local recurrence was observed, for a 5-year actuarial rate of 3.7 %. Neither regional nor distant failure was observed. Two patients died of internal disease. The 5-year disease-free, cancer-specific, and overall survival rates were 96.3, 100, and 95.1 %, respectively. Acute side effects included grade 1 (G1) erythema in 75 %, G1 parenchymal induration in 46 %, and G1 pain in 46 % of patients. No G2 or higher acute side effect occurred. Late side effects included G1, G2, and G3 fibrosis in 44, 7, and 2 % of patients, respectively, G1 skin pigmentation in 12 %, and G1 pain in 2 %. Asymptomatic fat necrosis occurred in 14 %. Cosmetic results were rated excellent or good in 86 % of cases by the patients themselves and 84 % by the physicians. The 5-year local tumor control, toxicity profile, and cosmetic results of APBI delivered with external beam 3D-CRT are encouraging and comparable to other APBI series. (orig.) [German] Evaluation der 5-Jahres-Ergebnisse bezueglich Ueberleben, Tumorkontrolle, Nebenwirkungen und Kosmetik nach Teilbrustbestrahlung (APBI) mittels 3-D-konformaler, akzelerierter Radiotherapie (3D-CRT). Zwischen 2006 und 2011 wurden 44 Patienten mit Brustkrebs im Stadium I-II und niedrigem Risikoprofil brusterhaltend operiert. Die adjuvante, 3-D-konformale APBI wurde mittels 3-5 nonkoplanarer Feldern durchgefuehrt. Die Gesamtdosis betrug 36,9 Gy bei 9 -mal 4,1 Gy b.i.d.. Nach

  12. High-density dental implants and radiotherapy planning: evaluation of effects on dose distribution using pencil beam convolution algorithm and Monte Carlo method.

    Science.gov (United States)

    Çatli, Serap

    2015-01-01

    High atomic number and density of dental implants leads to major problems at providing an accurate dose distribution in radiotherapy and contouring tumors and organs caused by the artifact in head and neck tumors. The limits and deficiencies of the algorithms using in the treatment planning systems can lead to large errors in dose calculation, and this may adversely affect the patient's treatment. In the present study, four commercial dental implants were used: pure titanium, titanium alloy (Ti-6Al-4V), amalgam, and crown. The effects of dental implants on dose distribution are determined with two methods: pencil beam convolution (PBC) algorithm and Monte Carlo code for 6 MV photon beam. The central axis depth doses were calculated on the phantom for a source-skin distance (SSD) of 100 cm and a 10 × 10 cm2 field using both of algorithms. The results of Monte Carlo method and Eclipse TPS were compared to each other and to those previously reported. In the present study, dose increases in tissue at a distance of 2 mm in front of the dental implants were seen due to the backscatter of electrons for dental implants at 6 MV using the Monte Carlo method. The Eclipse treatment planning system (TPS) couldn't precisely account for the backscatter radiation caused by the dental prostheses. TPS underestimated the back scatter dose and overestimated the dose after the dental implants. The large errors found for TPS in this study are due to the limits and deficiencies of the algorithms. The accuracy of the PBC algorithm of Eclipse TPS was evaluated in comparison to Monte Carlo calculations in consideration of the recommendations of the American Association of Physicists in Medicine Radiation Therapy Committee Task Group 65. From the comparisons of the TPS and Monte Carlo calculations, it is verified that the Monte Carlo simulation is a good approach to derive the dose distribution in heterogeneous media. PMID:26699323

  13. Accelerated partial breast irradiation with external beam three-dimensional conformal radiotherapy. Five-year results of a prospective phase II clinical study

    International Nuclear Information System (INIS)

    The aim of this study was to report the 5-year results of accelerated partial breast irradiation (APBI) using external beam three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2011, 44 patients with low-risk, stage I-II breast cancer underwent breast-conserving surgery. Postoperative APBI was given by means of 3D-CRT using three to five non-coplanar fields. The total dose of APBI was 36.9 Gy (nine fractions of 4.1 Gy b.i.d.). The mean follow-up time was 58.2 months for surviving patients. Survival results, side effects, and cosmetic results were assessed. One (2.3 %) local recurrence was observed, for a 5-year actuarial rate of 3.7 %. Neither regional nor distant failure was observed. Two patients died of internal disease. The 5-year disease-free, cancer-specific, and overall survival rates were 96.3, 100, and 95.1 %, respectively. Acute side effects included grade 1 (G1) erythema in 75 %, G1 parenchymal induration in 46 %, and G1 pain in 46 % of patients. No G2 or higher acute side effect occurred. Late side effects included G1, G2, and G3 fibrosis in 44, 7, and 2 % of patients, respectively, G1 skin pigmentation in 12 %, and G1 pain in 2 %. Asymptomatic fat necrosis occurred in 14 %. Cosmetic results were rated excellent or good in 86 % of cases by the patients themselves and 84 % by the physicians. The 5-year local tumor control, toxicity profile, and cosmetic results of APBI delivered with external beam 3D-CRT are encouraging and comparable to other APBI series. (orig.)

  14. SU-E-J-151: Dosimetric Evaluation of DIR Mapped Contours for Image Guided Adaptive Radiotherapy with 4D Cone-Beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Balik, S [Cleveland Clinic Foundation, Cleveland, OH (United States); Weiss, E; Williamson, J; Hugo, G [Virginia Commonwealth University, Richmond, VA (United States); Jan, N; Zhang, L [Virginia Commonwealth University, Richmond, Virginia (United States); Roman, N [San Antonio Precision Center Ctr, San Antonio, TX (United States); Christensen, G [University of Iowa, Iowa City, IA (United States)

    2014-06-01

    Purpose: To estimate dosimetric errors resulting from using contours deformably mapped from planning CT to 4D cone beam CT (CBCT) images for image-guided adaptive radiotherapy of locally advanced non-small cell lung cancer (NSCLC). Methods: Ten locally advanced non-small cell lung cancer (NSCLC) patients underwent one planning 4D fan-beam CT (4DFBCT) and weekly 4DCBCT scans. Multiple physicians delineated the gross tumor volume (GTV) and normal structures in planning CT images and only GTV in CBCT images. Manual contours were mapped from planning CT to CBCTs using small deformation, inverse consistent linear elastic (SICLE) algorithm for two scans in each patient. Two physicians reviewed and rated the DIR-mapped (auto) and manual GTV contours as clinically acceptable (CA), clinically acceptable after minor modification (CAMM) and unacceptable (CU). Mapped normal structures were visually inspected and corrected if necessary, and used to override tissue density for dose calculation. CTV (6mm expansion of GTV) and PTV (5mm expansion of CTV) were created. VMAT plans were generated using the DIR-mapped contours to deliver 66 Gy in 33 fractions with 95% and 100% coverage (V66) to PTV and CTV, respectively. Plan evaluation for V66 was based on manual PTV and CTV contours. Results: Mean PTV V66 was 84% (range 75% – 95%) and mean CTV V66 was 97% (range 93% – 100%) for CAMM scored plans (12 plans); and was 90% (range 80% – 95%) and 99% (range 95% – 100%) for CA scored plans (7 plans). The difference in V66 between CAMM and CA was significant for PTV (p = 0.03) and approached significance for CTV (p = 0.07). Conclusion: The quality of DIR-mapped contours directly impacted the plan quality for 4DCBCT-based adaptation. Larger safety margins may be needed when planning with auto contours for IGART with 4DCBCT images. Reseach was supported by NIH P01CA116602.

  15. Locally advanced prostate cancer: combination of high-dose high-precision radiotherapy and androgen deprivation therapy%Locally advanced prostate cancer:combination of high-dose high-precision radiotherapy and androgen deprivation therapy

    Institute of Scientific and Technical Information of China (English)

    Michel Bolla; René-Olivier Mirimanoff

    2014-01-01

    Locally advanced prostate cancer entails a risk of local,regional and systemic relapse requiring the combination of a Ioco-regional treatment,namely external beam radiotherapy(EBRT) to control the pelvic-confined disease,combined with a systemic therapy,namely androgen-deprivation therapy(ADT),to potentiate irradiation and to destroy the infra-clinical androgen-dependant disease outside the irradiated volume.Many phases Ⅲ randomized trials have paved the way in establishing the indications of this combined approach,which requires a long term ADT(≥2 years) with LHRH agonists.The duration of ADT may be reduced to 6 months should there be a significant comorbidity,a reluctance from the patient or a poor tolerance.A multidisciplinary approach will enable physicians to tailor the treatment strategy and a close cooperation between the specialists and the general practitioners will be set up to prevent as much as possible the side-effects of ADT.

  16. An imaging informatics-based system utilizing DICOM objects for treating pain in spinal cord injury patients utilizing proton beam radiotherapy

    Science.gov (United States)

    Verma, Sneha K.; Liu, Brent J.; Chun, Sophia; Gridley, Daila S.

    2014-03-01

    Many US combat personnel have sustained nervous tissue trauma during service, which often causes Neuropathic pain as a side effect and is difficult to manage. However in select patients, synapse lesioning can provide significant pain control. Our goal is to determine the effectiveness of using Proton Beam radiotherapy for treating spinal cord injury (SCI) related neuropathic pain as an alternative to invasive surgical lesioning. The project is a joint collaboration of USC, Spinal Cord Institute VA Healthcare System, Long Beach, and Loma Linda University. This is first system of its kind that supports integration and standardization of imaging informatics data in DICOM format; clinical evaluation forms outcomes data and treatment planning data from the Treatment planning station (TPS) utilized to administer the proton therapy in DICOM-RT format. It also supports evaluation of SCI subjects for recruitment into the clinical study, which includes the development, and integration of digital forms and tools for automatic evaluation and classification of SCI pain. Last year, we presented the concept for the patient recruitment module based on the principle of Bayesian decision theory. This year we are presenting the fully developed patient recruitment module and its integration to other modules. In addition, the DICOM module for integrating DICOM and DICOM-RT-ION data is also developed and integrated. This allows researchers to upload animal/patient study data into the system. The patient recruitment module has been tested using 25 retrospective patient data and DICOM data module is tested using 5 sets of animal data.

  17. Evaluation of deformable image registration for contour propagation between CT and cone-beam CT images in adaptive head and neck radiotherapy.

    Science.gov (United States)

    Li, X; Zhang, Y Y; Shi, Y H; Zhou, L H; Zhen, X

    2016-04-29

    Deformable image registration (DIR) is a critical technic in adaptive radiotherapy (ART) to propagate contours between planning computerized tomography (CT) images and treatment CT/Cone-beam CT (CBCT) image to account for organ deformation for treatment re-planning. To validate the ability and accuracy of DIR algorithms in organ at risk (OAR) contours mapping, seven intensity-based DIR strategies are tested on the planning CT and weekly CBCT images from six Head & Neck cancer patients who underwent a 6 ∼ 7 weeks intensity-modulated radiation therapy (IMRT). Three similarity metrics, i.e. the Dice similarity coefficient (DSC), the percentage error (PE) and the Hausdorff distance (HD), are employed to measure the agreement between the propagated contours and the physician delineated ground truths. It is found that the performance of all the evaluated DIR algorithms declines as the treatment proceeds. No statistically significant performance difference is observed between different DIR algorithms (p> 0.05), except for the double force demons (DFD) which yields the worst result in terms of DSC and PE. For the metric HD, all the DIR algorithms behaved unsatisfactorily with no statistically significant performance difference (p= 0.273). These findings suggested that special care should be taken when utilizing the intensity-based DIR algorithms involved in this study to deform OAR contours between CT and CBCT, especially for those organs with low contrast. PMID:27259084

  18. Detector to detector corrections: A comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams

    Energy Technology Data Exchange (ETDEWEB)

    Azangwe, Godfrey, E-mail: g.azangwe@iaea.org; Grochowska, Paulina; Izewska, Joanna; Meghzifene, Ahmed [International Atomic Energy Agency, Vienna International Centre, PO Box 100, 1400 Vienna (Austria); Georg, Dietmar; Hopfgartner, Johannes; Lechner, Wolfgang [Department of Radiation Oncology, Medical University Vienna/AKH Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria and Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University Vienna, Vienna, Währinger Gürtel 18-20, A-1090 Vienna (Austria); Andersen, Claus E.; Beierholm, Anders R.; Helt-Hansen, Jakob [Center for Nuclear Technologies, Technical University of Denmark, Risø Campus, DK-4000 Roskilde (Denmark); Mizuno, Hideyuki; Fukumura, Akifumi [National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba-shi 263-8555 (Japan); Yajima, Kaori [Association for Nuclear Technology in Medicine, 7-16, Nihonbashikodenmacho, chuou-ku, Tokyo 103-0001 (Japan); Gouldstone, Clare; Sharpe, Peter [National Physical Laboratory, Acoustics and Ionising Radiation Division, Teddington TW11 0LW (United Kingdom); Palmans, Hugo [National Physical Laboratory, Acoustics and Ionising Radiation Division, Teddington TW11 0LW, United Kingdom and EBG MedAustron GmbH, Medical Physics Department, A-2700 Wiener Neustadt (Austria)

    2014-07-15

    Purpose: The aim of the present study is to provide a comprehensive set of detector specific correction factors for beam output measurements for small beams, for a wide range of real time and passive detectors. The detector specific correction factors determined in this study may be potentially useful as a reference data set for small beam dosimetry measurements. Methods: Dose response of passive and real time detectors was investigated for small field sizes shaped with a micromultileaf collimator ranging from 0.6 × 0.6 cm{sup 2} to 4.2 × 4.2 cm{sup 2} and the measurements were extended to larger fields of up to 10 × 10 cm{sup 2}. Measurements were performed at 5 cm depth, in a 6 MV photon beam. Detectors used included alanine, thermoluminescent dosimeters (TLDs), stereotactic diode, electron diode, photon diode, radiophotoluminescent dosimeters (RPLDs), radioluminescence detector based on carbon-doped aluminium oxide (Al{sub 2}O{sub 3}:C), organic plastic scintillators, diamond detectors, liquid filled ion chamber, and a range of small volume air filled ionization chambers (volumes ranging from 0.002 cm{sup 3} to 0.3 cm{sup 3}). All detector measurements were corrected for volume averaging effect and compared with dose ratios determined from alanine to derive a detector correction factors that account for beam perturbation related to nonwater equivalence of the detector materials. Results: For the detectors used in this study, volume averaging corrections ranged from unity for the smallest detectors such as the diodes, 1.148 for the 0.14 cm{sup 3} air filled ionization chamber and were as high as 1.924 for the 0.3 cm{sup 3} ionization chamber. After applying volume averaging corrections, the detector readings were consistent among themselves and with alanine measurements for several small detectors but they differed for larger detectors, in particular for some small ionization chambers with volumes larger than 0.1 cm{sup 3}. Conclusions: The results demonstrate

  19. Dosimetric comparison of flattened and unflattened beams for stereotactic ablative radiotherapy of stage I non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hrbacek, Jan, E-mail: jan.hrbacek@psi.ch [Klinik für Radio-Onkologie, UniversitätsSpital Zürich, 8091 Zürich, Switzerland and Center for Proton Therapy, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Lang, Stephanie; Graydon, Shaun N.; Klöck, Stephan; Riesterer, Oliver [Klinik für Radio-Onkologie, UniversitätsSpital Zürich, 8091 Zürich (Switzerland)

    2014-03-15

    Purpose: To compare contribution and accuracy of delivery for two flattening filter free (FFF) beams of the nominal energy 6 and 10 MV and a 6 MV flattened beam for early stage lung cancer. Methods: For each of 11 patients with stage I nonsmall cell lung cancer three volumetric modulated arc therapy plans were prepared utilizing a 6 MV flattened photon beam (X6FF) and two nonflattened beams of nominal energy 6 and 10 MV (X6FFF, X10FFF). Optimization constraints were set to produce dose distributions that meet the criteria of the RTOG-0915 protocol. The radiation schedule used for plan comparison in all patients was 50 Gy in five fractions. Dosimetric parameters of planning target volume (PTV) and organs-at-risk and delivery times were assessed and compared. All plans were subject to verification using Delta{sup 4} unit (Scandidos, Sweden) and absolutely calibrated gafchromic films in a thorax phantom. Results: All plans had a qualitatively comparable outcome. Obtained dose distributions were conformal (CI < 1.17) and exhibited a steep dose fall-off outside the PTV. The ratio of monitor units for FFF versus FF plans in the authors' study ranged from 0.95 to 1.21 and from 0.93 to 1.25 for X6FFF/X6FF and X10FFF/X6FF comparisons, respectively. The ratio systematically increased with increasing size of the PTV (up to +25% for 150 cm{sup 3} PTV). Yet the integral dose to healthy tissue did not follow this trend. Comparison of cumulative dose volume histograms for a patient's body showed that X6FFF plans exhibit improved conformity and reduced the volume of tissue that received more than 50% of the prescription dose. Parameters related to dose gradient showed statistically significant improvement. CI{sub 50%}, CI{sub 60%}, CI{sub 80%}, and CI{sub 100%} were on average reduced by 4.6% (p < 0.001), 4.6% (p = 0.002), 3.1% (p = 0.002), and 1.2% (p = 0.039), respectively. Gradient measure was on average reduced by 4.2% (p < 0.001). Due to dose reduction in the

  20. Expanded risk groups help determine which prostate radiotherapy sub-group may benefit from adjuvant androgen deprivation therapy

    Directory of Open Access Journals (Sweden)

    Williams Scott G

    2008-04-01

    Full Text Available Abstract Purpose To assess whether an expanded (five level risk stratification system can be used to identify the sub-group of intermediate risk patients with prostate cancer who benefit from combining androgen deprivation therapy (ADT with external beam radiotherapy (EBRT. Materials and methods Using a previously validated 5-risk group schema, a prospective non-randomized data set of 1423 men treated at the British Columbia Cancer Agency was assessed for the primary end point of biochemical control (bNED with the RTOG-ASTRO "Phoenix" definition (lowest PSA to date + 2 ng/mL, both with and without adjuvant ADT. The median follow-up was 5 years. Results There was no bNED benefit for ADT in the low or low intermediate groups but there was a statistically significant bNED benefit in the high intermediate, high and extreme risk groups. The 5-year bNED rates with and without ADT were 70% and 73% respectively for the low intermediate group (p = non-significant and 72% and 58% respectively for the high intermediate group (p = 0.002. Conclusion There appears to be no advantage to ADT where the Gleason score is 6 or less and PSA is 15 or less. ADT is beneficial in patients treated to standard dose radiation with Gleason 6 disease and a PSA greater than 15 or where the Gleason score is 7 or higher.

  1. mARC vs. IMRT radiotherapy of the prostate with flat and flattening-filter-free beam energies

    International Nuclear Information System (INIS)

    There as yet exists no systematic planning study investigating the novel mARC rotational radiotherapy technique, which is conceptually different from VMAT. We therefore present a planning study for prostate cancer, comparing mARC with IMRT treatment at the same linear accelerator equipped with flat and flattening-filter-free (FFF) photon energies. We retrospectively re-contoured and re-planned treatment plans for 10 consecutive prostate cancer patients. Plans were created for a Siemens Artiste linear accelerator with flat 6 MV and FFF 7 MV photons, using the Prowess Panther treatment planning system. mARC and IMRT plans were compared with each other considering indices for plan quality and dose to organs at risk. All plans were exported to the machine and irradiated while measuring scattered dose by thermoluminescent dosimeters placed on an anthropomorphic phantom. Treatment times were also measured and compared. All plans were found acceptable for treatment. There was no marked preference for either technique or energy from the point of view of target coverage and dose to organs at risk. Scattered dose was significantly decreased by the use of FFF energies. While mARC and IMRT plans were of very similar overall quality, treatment time could be markedly decreased both by the use of mARC and FFF energy. Highly conformal treatment plans could be created both by the use of flat 6 MV and FFF 7 MV energy, using IMRT or mARC. For all practical purposes, the FFF 7 MV energy and mARC plans are acceptable for treatment, a combination of both allowing a drastic reduction in treatment time from over 5 minutes to about half this value

  2. Detector to detector corrections: a comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams

    DEFF Research Database (Denmark)

    Azangwe, Godfrey; Grochowska, Paulina; Georg, Dietmar;

    2014-01-01

    useful as a reference data set for small beam dosimetry measurements. Methods: Dose response of passive and real time detectors was investigated for small field sizes shaped with a micromultileaf collimator ranging from 0.6 × 0.6 cm2 to 4.2 × 4.2 cm2 and the measurements were extended to larger fields...... that depending on the choice of detectors, there is a potential for large errors when effects such as volume averaging, perturbation and differences in material properties of detectors are not taken into account. As the commissioning of small fields for clinical treatment has to rely on accurate dose...

  3. Range degradation and distal edge behavior of proton radiotherapy beams using 11C activation and Monte Carlo simulation

    Science.gov (United States)

    Elmekawy, Ahmed Farouk

    The distal edge of therapeutic proton radiation beams was investigated by different methods. Proton beams produced at the Hampton University Proton Therapy Institute (HUPTI) were used to irradiate a Polymethylmethacrylate (PMMA) phantom for three different ranges (13.5, 17.0 and 21.0 cm) to investigate the distal slope dependence of the Bragg peak. The activation of 11 C was studied by scanning the phantom less than 10 minutes post-irradiation with a Philips Big Bore Gemini(c) PET/CT. The DICOM images were imported into the Varian Eclipse(c) Treatment Planning System (TPS) for analysis and then analyzed by ImageJ(c) . The distal slope ranged from ?0.1671 +/- 0.0036 to -0.1986 +/- 0.0052 (pixel intensity/slice number) for ranges 13.5 to 21.0 cm respectively. A realistic description of the setup was modeled using the GATE 7.0 Monte Carlo simulation tool and compared to the experiment data. The results show the distal slope ranged from -0.1158+/-0.0133 to -0.0787+/-0.002 (Gy/mm). Additionally, low activity, 11C were simulated to study the 11C reconstructed half-life dependence versus the initial activity for six ranges chosen around the previous activation study. The results of the expected/nominal half-life vs. activity ranged from -5 x 10-4 +/- 2.8104 x 10-4 to 1.6 x 10-3 +/- 9.44 x 10-4 (%diff./Bq). The comparison between two experiments with proton beams on a PMMA phantom and multi-layer ion chamber, and two GATE simulations of a proton beam incident on a water phantom and 11C PET study show that: (i) the distal fall-off variation of the steepness of the slopes are found to be similar thus validating the sensitivity of the PET technique to the range degradation and (ii) the average of the super-ratios difference between all studies observed is primarily due to the difference in the dose deposited in the media.

  4. Trends in the Utilization of Adjuvant Vaginal Cuff Brachytherapy and/or External Beam Radiation Treatment in Stage I and II Endometrial Cancer: A Surveillance, Epidemiology, and End-Results Study

    International Nuclear Information System (INIS)

    Purpose: The optimal adjuvant radiation treatment for endometrial carcinoma (EC) remains controversial. Adjuvant vaginal cuff brachytherapy (VB) has emerged as an increasingly common treatment modality. However, the time trends for using VB, external beam radiation therapy (EBRT), or combined therapy (VB+EBRT) have not been well characterized. We therefore examined the utilization trends of VB, EBRT, and VB+EBRT for adjuvant RT in International Federation of Gynecologic Oncology (FIGO) stage I and II EC over time. Methods and Materials: We evaluated treatment patterns for 48,122 patients with EC diagnosed between January 1995 and December 2005, using the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) public use database. Chi-squared tests were used to assess differences by radiation type (VB, EBRT, and VB+EBRT) and various demographic and clinical variables. Results: Analyses were limited to 9,815 patients (20.4%) with EC who met the inclusion criteria. Among women who received adjuvant RT, the proportion receiving VB increased yearly (12.9% in 1995 compared to 32.8% in 2005 (p < 0.0001). The increasing use of VB was proportional to the decreasing use of EBRT (56.1% in 1995 to 45.8% in 2005; p < 0.0001) and VB+EBRT (31.0% in 1995 to 21.4% in 2005; p < 0.001). Conclusions: This population-based report demonstrates an increasing trend in the use of VB in the adjuvant setting after hysterectomy for treatment of women with FIGO stage I II EC. VB alone appears to be replacing pelvic EBRT and VB+EBRT therapy in the management of stage I–II EC.

  5. Trends in the Utilization of Adjuvant Vaginal Cuff Brachytherapy and/or External Beam Radiation Treatment in Stage I and II Endometrial Cancer: A Surveillance, Epidemiology, and End-Results Study

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Mehul K. [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Cote, Michele L. [Karmanos Cancer Institute and Wayne State University, Detroit, Michigan (United States); Ali-Fehmi, Rouba [Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan (United States); Buekers, Thomas; Munkarah, Adnan R. [Department of Women' s Health Services, Division of Gynecologic Oncology, Henry Ford Health System, Detroit, Michigan (United States); Elshaikh, Mohamed A., E-mail: melshai1@hfhs.org [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States)

    2012-05-01

    Purpose: The optimal adjuvant radiation treatment for endometrial carcinoma (EC) remains controversial. Adjuvant vaginal cuff brachytherapy (VB) has emerged as an increasingly common treatment modality. However, the time trends for using VB, external beam radiation therapy (EBRT), or combined therapy (VB+EBRT) have not been well characterized. We therefore examined the utilization trends of VB, EBRT, and VB+EBRT for adjuvant RT in International Federation of Gynecologic Oncology (FIGO) stage I and II EC over time. Methods and Materials: We evaluated treatment patterns for 48,122 patients with EC diagnosed between January 1995 and December 2005, using the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) public use database. Chi-squared tests were used to assess differences by radiation type (VB, EBRT, and VB+EBRT) and various demographic and clinical variables. Results: Analyses were limited to 9,815 patients (20.4%) with EC who met the inclusion criteria. Among women who received adjuvant RT, the proportion receiving VB increased yearly (12.9% in 1995 compared to 32.8% in 2005 (p < 0.0001). The increasing use of VB was proportional to the decreasing use of EBRT (56.1% in 1995 to 45.8% in 2005; p < 0.0001) and VB+EBRT (31.0% in 1995 to 21.4% in 2005; p < 0.001). Conclusions: This population-based report demonstrates an increasing trend in the use of VB in the adjuvant setting after hysterectomy for treatment of women with FIGO stage I-II EC. VB alone appears to be replacing pelvic EBRT and VB+EBRT therapy in the management of stage I-II EC.

  6. Randomized Control Trial: Evaluating Aluminum-Based Antiperspirant Use, Axilla Skin Toxicity, and Reported Quality of Life in Women Receiving External Beam Radiotherapy for Treatment of Stage 0, I, and II Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Linda C., E-mail: Linda.watson@albertahealthservices.ca [Department of Interdisciplinary Practice, Community Oncology, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Gies, Donna [Department of Radiation Oncology Nursing, Tom Baker Cancer Centre, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Thompson, Emmanuel [Department of Mathematics and Statistics, University of Calgary Faculty of Science, Calgary, AB (Canada); Thomas, Bejoy [Department of Psychosocial Resources, Tom Baker Cancer Centre, Alberta Health Services-Cancer Care, Calgary, AB (Canada); Department of Psychosocial Oncology, University of Calgary Faculty of Medicine, Calgary, AB (Canada)

    2012-05-01

    Purpose: Standard skin care instructions regarding the use of antiperspirants during radiotherapy to the breast varies across North America. Women have articulated that when instructed to not use antiperspirant, the potential for body odor is distressing. Historical practices and individual opinions have often guided practice in this field. The present study had 2 purposes. To evaluate whether the use of aluminum-based antiperspirant while receiving external beam radiotherapy for stage 0, I, or II breast cancer will increase axilla skin toxicity and to evaluate whether the use of antiperspirant during external beam radiotherapy improves quality of life. Methods: A total of 198 participants were randomized to either the experimental group (antiperspirant) or control group (standard care-wash only). The skin reactions in both groups were measured weekly and 2 weeks after treatment using the National Cancer Institute Common Toxicity Criteria Adverse Events, version 3, toxicity grading criteria. Both groups completed the Functional Assessment for Chronic Illness Therapy's questionnaire for the breast population quality of life assessment tool, with additional questions evaluating the effect of underarm antiperspirant use on quality of life before treatment, immediately after treatment, and 2 weeks after treatment during the study. Results: The skin reaction data were analyzed using the generalized estimating equation. No statistically significant difference was seen in the skin reaction between the 2 groups over time. The quality of life data also revealed no statistically significant difference between the 2 groups over time. Conclusions: Data analysis indicates that using antiperspirant routinely during external beam radiotherapy for Stage 0, I, or II breast cancer does not affect the intensity of the skin reaction or the self-reported quality of life. This evidence supports that in this particular population, there is no purpose to restrict these women from

  7. Randomized Control Trial: Evaluating Aluminum-Based Antiperspirant Use, Axilla Skin Toxicity, and Reported Quality of Life in Women Receiving External Beam Radiotherapy for Treatment of Stage 0, I, and II Breast Cancer

    International Nuclear Information System (INIS)

    Purpose: Standard skin care instructions regarding the use of antiperspirants during radiotherapy to the breast varies across North America. Women have articulated that when instructed to not use antiperspirant, the potential for body odor is distressing. Historical practices and individual opinions have often guided practice in this field. The present study had 2 purposes. To evaluate whether the use of aluminum-based antiperspirant while receiving external beam radiotherapy for stage 0, I, or II breast cancer will increase axilla skin toxicity and to evaluate whether the use of antiperspirant during external beam radiotherapy improves quality of life. Methods: A total of 198 participants were randomized to either the experimental group (antiperspirant) or control group (standard care-wash only). The skin reactions in both groups were measured weekly and 2 weeks after treatment using the National Cancer Institute Common Toxicity Criteria Adverse Events, version 3, toxicity grading criteria. Both groups completed the Functional Assessment for Chronic Illness Therapy’s questionnaire for the breast population quality of life assessment tool, with additional questions evaluating the effect of underarm antiperspirant use on quality of life before treatment, immediately after treatment, and 2 weeks after treatment during the study. Results: The skin reaction data were analyzed using the generalized estimating equation. No statistically significant difference was seen in the skin reaction between the 2 groups over time. The quality of life data also revealed no statistically significant difference between the 2 groups over time. Conclusions: Data analysis indicates that using antiperspirant routinely during external beam radiotherapy for Stage 0, I, or II breast cancer does not affect the intensity of the skin reaction or the self-reported quality of life. This evidence supports that in this particular population, there is no purpose to restrict these women from using

  8. Simulation of an antiprotons beam applied to the radiotherapy; Simulacao de um feixe de antiprotons aplicado a radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Prata, Leonardo de Almeida

    2006-07-15

    Results for the interaction of a antiproton beam with constituent nuclei of the organic matter are presented. This method regards of the application of an computational algorithm to determine quantitatively the differential cross sections for the scattered particles, starting from the interaction of these antiprotons with the nuclei, what will allow in the future to draw the isodose curve for antiproton therapy, once these beams are expected to be used in cancer treatment soon. The calculation will be done through the application of the concepts of the method of intranuclear cascade, providing yield and differential cross sections of the scattered particles, present in the software MCMC. Th algorithm was developed based on Monte Carlo's method, already taking into account a validate code. The following physical quantities are presented: the yield of secondary particles, their spectral and angular distributions for these interactions. For the energy range taken into account the more important emitted particles are protons, neutrons and pions. Results shown that emitted secondary particles can modify the isodose curves, because they present high yield and energy for transverse directions. (author)

  9. On-Line Use of Three-Dimensional Marker Trajectory Estimation From Cone-Beam Computed Tomography Projections for Precise Setup in Radiotherapy for Targets With Respiratory Motion

    International Nuclear Information System (INIS)

    Purpose: To develop and evaluate accurate and objective on-line patient setup based on a novel semiautomatic technique in which three-dimensional marker trajectories were estimated from two-dimensional cone-beam computed tomography (CBCT) projections. Methods and Materials: Seven treatment courses of stereotactic body radiotherapy for liver tumors were delivered in 21 fractions in total to 6 patients by a linear accelerator. Each patient had two to three gold markers implanted close to the tumors. Before treatment, a CBCT scan with approximately 675 two-dimensional projections was acquired during a full gantry rotation. The marker positions were segmented in each projection. From this, the three-dimensional marker trajectories were estimated using a probability based method. The required couch shifts for patient setup were calculated from the mean marker positions along the trajectories. A motion phantom moving with known tumor trajectories was used to examine the accuracy of the method. Trajectory-based setup was retrospectively used off-line for the first five treatment courses (15 fractions) and on-line for the last two treatment courses (6 fractions). Automatic marker segmentation was compared with manual segmentation. The trajectory-based setup was compared with setup based on conventional CBCT guidance on the markers (first 15 fractions). Results: Phantom measurements showed that trajectory-based estimation of the mean marker position was accurate within 0.3 mm. The on-line trajectory-based patient setup was performed within approximately 5 minutes. The automatic marker segmentation agreed with manual segmentation within 0.36 ± 0.50 pixels (mean ± SD; pixel size, 0.26 mm in isocenter). The accuracy of conventional volumetric CBCT guidance was compromised by motion smearing (≤21 mm) that induced an absolute three-dimensional setup error of 1.6 ± 0.9 mm (maximum, 3.2) relative to trajectory-based setup. Conclusions: The first on-line clinical use of

  10. On-Line Use of Three-Dimensional Marker Trajectory Estimation From Cone-Beam Computed Tomography Projections for Precise Setup in Radiotherapy for Targets With Respiratory Motion

    Energy Technology Data Exchange (ETDEWEB)

    Worm, Esben S., E-mail: esbeworm@rm.dk [Department of Oncology, Aarhus University Hospital, Aarhus (Denmark); Department of Medical Physics, Aarhus University Hospital, Aarhus (Denmark); Hoyer, Morten; Fledelius, Walther [Department of Oncology, Aarhus University Hospital, Aarhus (Denmark); Nielsen, Jens E.; Larsen, Lars P. [Department of Radiology, Aarhus University Hospital, Aarhus (Denmark); Poulsen, Per R. [Department of Oncology, Aarhus University Hospital, Aarhus (Denmark); Institute of Clinical Medicine, Aarhus University (Denmark)

    2012-05-01

    Purpose: To develop and evaluate accurate and objective on-line patient setup based on a novel semiautomatic technique in which three-dimensional marker trajectories were estimated from two-dimensional cone-beam computed tomography (CBCT) projections. Methods and Materials: Seven treatment courses of stereotactic body radiotherapy for liver tumors were delivered in 21 fractions in total to 6 patients by a linear accelerator. Each patient had two to three gold markers implanted close to the tumors. Before treatment, a CBCT scan with approximately 675 two-dimensional projections was acquired during a full gantry rotation. The marker positions were segmented in each projection. From this, the three-dimensional marker trajectories were estimated using a probability based method. The required couch shifts for patient setup were calculated from the mean marker positions along the trajectories. A motion phantom moving with known tumor trajectories was used to examine the accuracy of the method. Trajectory-based setup was retrospectively used off-line for the first five treatment courses (15 fractions) and on-line for the last two treatment courses (6 fractions). Automatic marker segmentation was compared with manual segmentation. The trajectory-based setup was compared with setup based on conventional CBCT guidance on the markers (first 15 fractions). Results: Phantom measurements showed that trajectory-based estimation of the mean marker position was accurate within 0.3 mm. The on-line trajectory-based patient setup was performed within approximately 5 minutes. The automatic marker segmentation agreed with manual segmentation within 0.36 {+-} 0.50 pixels (mean {+-} SD; pixel size, 0.26 mm in isocenter). The accuracy of conventional volumetric CBCT guidance was compromised by motion smearing ({<=}21 mm) that induced an absolute three-dimensional setup error of 1.6 {+-} 0.9 mm (maximum, 3.2) relative to trajectory-based setup. Conclusions: The first on-line clinical use of

  11. Review of ultrasound image guidance in external beam radiotherapy part II: intra-fraction motion management and novel applications

    Science.gov (United States)

    O'Shea, Tuathan; Bamber, Jeffrey; Fontanarosa, Davide; van der Meer, Skadi; Verhaegen, Frank; Harris, Emma

    2016-04-01

    Imaging has become an essential tool in modern radiotherapy (RT), being used to plan dose delivery prior to treatment and verify target position before and during treatment. Ultrasound (US) imaging is cost-effective in providing excellent contrast at high resolution for depicting soft tissue targets apart from those shielded by the lungs or cranium. As a result, it is increasingly used in RT setup verification for the measurement of inter-fraction motion, the subject of Part I of this review (Fontanarosa et al 2015 Phys. Med. Biol. 60 R77-114). The combination of rapid imaging and zero ionising radiation dose makes US highly suitable for estimating intra-fraction motion. The current paper (Part II of the review) covers this topic. The basic technology for US motion estimation, and its current clinical application to the prostate, is described here, along with recent developments in robust motion-estimation algorithms, and three dimensional (3D) imaging. Together, these are likely to drive an increase in the number of future clinical studies and the range of cancer sites in which US motion management is applied. Also reviewed are selections of existing and proposed novel applications of US imaging to RT. These are driven by exciting developments in structural, functional and molecular US imaging and analytical techniques such as backscatter tissue analysis, elastography, photoacoustography, contrast-specific imaging, dynamic contrast analysis, microvascular and super-resolution imaging, and targeted microbubbles. Such techniques show promise for predicting and measuring the outcome of RT, quantifying normal tissue toxicity, improving tumour definition and defining a biological target volume that describes radiation sensitive regions of the tumour. US offers easy, low cost and efficient integration of these techniques into the RT workflow. US contrast technology also has potential to be used actively to assist RT by manipulating the tumour cell environment and by

  12. Review of ultrasound image guidance in external beam radiotherapy part II: intra-fraction motion management and novel applications.

    Science.gov (United States)

    O'Shea, Tuathan; Bamber, Jeffrey; Fontanarosa, Davide; van der Meer, Skadi; Verhaegen, Frank; Harris, Emma

    2016-04-21

    Imaging has become an essential tool in modern radiotherapy (RT), being used to plan dose delivery prior to treatment and verify target position before and during treatment. Ultrasound (US) imaging is cost-effective in providing excellent contrast at high resolution for depicting soft tissue targets apart from those shielded by the lungs or cranium. As a result, it is increasingly used in RT setup verification for the measurement of inter-fraction motion, the subject of Part I of this review (Fontanarosa et al 2015 Phys. Med. Biol. 60 R77-114). The combination of rapid imaging and zero ionising radiation dose makes US highly suitable for estimating intra-fraction motion. The current paper (Part II of the review) covers this topic. The basic technology for US motion estimation, and its current clinical application to the prostate, is described here, along with recent developments in robust motion-estimation algorithms, and three dimensional (3D) imaging. Together, these are likely to drive an increase in the number of future clinical studies and the range of cancer sites in which US motion management is applied. Also reviewed are selections of existing and proposed novel applications of US imaging to RT. These are driven by exciting developments in structural, functional and molecular US imaging and analytical techniques such as backscatter tissue analysis, elastography, photoacoustography, contrast-specific imaging, dynamic contrast analysis, microvascular and super-resolution imaging, and targeted microbubbles. Such techniques show promise for predicting and measuring the outcome of RT, quantifying normal tissue toxicity, improving tumour definition and defining a biological target volume that describes radiation sensitive regions of the tumour. US offers easy, low cost and efficient integration of these techniques into the RT workflow. US contrast technology also has potential to be used actively to assist RT by manipulating the tumour cell environment and by

  13. Nanoparticle-guided radiotherapy

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention relates to a method and nano-sized particles for image guided radiotherapy (IGRT) of a target tissue. More specifically, the invention relates to nano-sized particles comprising X-ray-imaging contrast agents in solid form with the ability to block x-rays, allowing for simult......The present invention relates to a method and nano-sized particles