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Sample records for radiotherapy fraction size

  1. Comparative evaluation of multiple fractions per day radiotherapy and conventional fractionated radiotherapy in squamous cell carcinoma of esophagus

    International Nuclear Information System (INIS)

    Andrabi, W.H.; Akhtar, S.; Kharadi, M.Y.; Mushtaq, G.; Zargar, S.A.

    1999-01-01

    Dose fractionated is important in radiotherapy in order to achieve the desired results. There are regimes which are accepted and followed worldwide. Five fractions per week for a full course of treatment is regarded as standard fractionation regimen. Interest has lately been developed to alter this and try regimes like hyper and accelerated fractionations. In the former, smaller doses per fraction than usual are given in several fractions on each treating day, with no change in overall time. In the latter, conventionally sized fractions are given as two or three per day with a shortening of overall time. As the dose fraction in our case is high, we spilt the full course of treatment introducing a gap of one week between the treatment schedules. The results obtained are fairly good in comparison with conventional radiotherapy regimes. (author)

  2. Role of radiotherapy fractionation in head and neck cancers (MARCH)

    DEFF Research Database (Denmark)

    Lacas, Benjamin; Bourhis, Jean; Overgaard, Jens

    2017-01-01

    BACKGROUND: The Meta-Analysis of Radiotherapy in squamous cell Carcinomas of Head and neck (MARCH) showed that altered fractionation radiotherapy is associated with improved overall and progression-free survival compared with conventional radiotherapy, with hyperfractionated radiotherapy showing...... the greatest benefit. This update aims to confirm and explain the superiority of hyperfractionated radiotherapy over other altered fractionation radiotherapy regimens and to assess the benefit of altered fractionation within the context of concomitant chemotherapy with the inclusion of new trials. METHODS......: For this updated meta-analysis, we searched bibliography databases, trials registries, and meeting proceedings for published or unpublished randomised trials done between Jan 1, 2009, and July 15, 2015, comparing primary or postoperative conventional fractionation radiotherapy versus altered fractionation...

  3. Second Study of Hyper-Fractionated Radiotherapy

    Directory of Open Access Journals (Sweden)

    R. Jacob

    1999-01-01

    Full Text Available Purpose and Method. Hyper-fractionated radiotherapy for treatment of soft tissue sarcomas is designed to deliver a higher total dose of radiation without an increase in late normal tissue damage. In a previous study at the Royal Marsden Hospital, a total dose of 75 Gy using twice daily 1.25 Gy fractions resulted in a higher incidence of late damage than conventional radiotherapy using 2 Gy daily fractions treating to a total of 60 Gy. The current trial therefore used a lower dose per fraction of 1.2 Gy and lower total dose of 72 Gy, with 60 fractions given over a period of 6 weeks.

  4. Effect of set up time on sublethal repair in multifield fractionated radiotherapy

    International Nuclear Information System (INIS)

    Kehwar, T.S.; Beriwal, Sushil; Sharma, S.C.

    1998-01-01

    The sublethal repair between two doses given with a variable time interval for mammalian cells in tissue culture was first demonstrated successfully by Elkind and Sutton. Subsequently on the basis of concept of sublethal damage repair between fractions, the radio therapists and radio biologists realized that dose can be increased by increasing the small size fractions. This concept is successfully being used in modern radiotherapy

  5. Impact of Fraction Size on Cardiac Mortality in Women Treated With Tangential Radiotherapy for Localized Breast Cancer

    International Nuclear Information System (INIS)

    Marhin, Wilson; Wai, Elaine; Tyldesley, Scott

    2007-01-01

    Purpose: To determine whether fraction size affects the risk of cardiac mortality in women treated with adjuvant radiotherapy (RT) for left-sided breast cancer. Methods and Materials: A population-based retrospective study of women with a diagnosis of localized breast cancer treated with adjuvant RT in British Columbia from 1984 to 2000. Cases were identified from the British Columbia Cancer Agency database. Overall and cardiac-specific survival were compared for women treated with RT for left- vs. right-sided breast cancer. We analyzed the impact of age (≤60 vs. >60 years) at diagnosis and RT fraction size (≤2 vs. >2 Gy) on risk of fatal cardiac events. Results: We identified 3,781 women with left-sided and 3,666 women with right-sided breast cancer who received adjuvant RT. Median follow-up was 7.9 years. There were 52 vs. 47 breast cancer deaths in women treated for left- and right-sided breast cancer, respectively. There was no significant difference in cardiac mortality for women ≤60 or >60 years of age who received adjuvant RT for left-sided vs. right-sided cancer. There was no difference in cardiac mortality for women who received adjuvant RT with fraction sizes ≤2 vs. >2 Gy for left- or right-sided cancer. Conclusions: There was no evidence for increased risk of cardiac mortality in women treated with adjuvant RT after a median follow-up of 7.9 years in our cohort. Hypofractionated adjuvant RT regimens did not significantly increase the risk of cardiac mortality

  6. Small-field fractionated radiotherapy with or without stereotactic boost for vestibular schwannoma

    International Nuclear Information System (INIS)

    Kagei, K.; Shirato, H.; Suzuki, K.; Isu, T.; Sawamura, Y.; Sakamoto, T.; Fukuda, S.; Nishioka, T.; Hashimoto, S.; Miyasaka, K.

    1999-01-01

    Purpose: To assess the efficacy and toxicity of small-field fractionated radiotherapy with or without stereotactic boost (SB) for vestibular schwannomas.Methods and materials: Thirty-nine patients with vestibular schwannoma were treated with irradiation between March 1991 and February 1996. Extra-meatal tumor diameters were under 30 mm. Thirty-three patients received small-field fractionated radiotherapy followed by SB. Basic dose schedule was 44 Gy in 22 fractions over 5 1/2 weeks plus 4 Gy in one session. Six patients received small-field fractionated radiotherapy only (40-44 Gy in 20-22 fractions over 5-5 1/2 weeks or 36 Gy in 20 fractions over 5 weeks).< Results: Follow-up ranged from 6 to 69 months (median, 24 months). Tumors decreased in size in 13 cases (33%), were unchanged in 25 (64%), and increased in one (3%). The actuarial 2-year tumor control rate was 97%. Fifteen patients had useful hearing (Gardner-Robertson class 1-2) and 25 patients had testable hearing (class 1-4) before irradiation. The 2-year actuarial rates of useful hearing preservation (free of deterioration from class 1-2 to class 3-5) were 78%. The 2-year actuarial rates of any testable hearing preservation (free of deterioration from class 1-4 to class 5) were 96%. No permanent facial and trigeminal neuropathy developed after irradiation. The 2-year actuarial incidences of facial and trigeminal neuropathies were 8% and 16%, respectively.Conclusions: Small-field fractionated radiotherapy with or without SB provides excellent short-term local control and a relatively low incidence of complications for vestibular schwannoma, although further follow-up is necessary to evaluate the long-term results. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Estimating radiotherapy demands in South East Asia countries in 2025 and 2035 using evidence-based optimal radiotherapy fractions.

    Science.gov (United States)

    Yahya, Noorazrul; Roslan, Nurhaziqah

    2018-01-08

    As about 50% of cancer patients may require radiotherapy, the demand of radiotherapy as the main treatment to treat cancer is likely to rise due to rising cancer incidence. This study aims to quantify the radiotherapy demand in countries in Southeast Asia (SEA) in 2025 and 2035 using evidence-based optimal radiotherapy fractions. SEA country-specific cancer incidence by tumor site for 2015, 2025 and 2035 was extracted from the GLOBOCAN database. We utilized the optimal radiotherapy utilization rate model by Wong et al. (2016) to calculate the optimal number of fractions for all tumor sites in each SEA country. The available machines (LINAC & Co-60) were extracted from the IAEA's Directory of Radiotherapy Centres (DIRAC) from which the number of available fractions was calculated. The incidence of cancers in SEA countries are expected to be 1.1 mil cases (2025) and 1.4 mil (2035) compared to 0.9 mil (2015). The number of radiotherapy fractions needed in 2025 and 2035 are 11.1 and 14.1 mil, respectively, compared to 7.6 mil in 2015. In 2015, the radiotherapy fulfillment rate (RFR; required fractions/available fractions) varied between countries with Brunei, Singapore and Malaysia are highest (RFR > 1.0 - available fractions > required fractions), whereas Cambodia, Indonesia, Laos, Myanmar, Philippines, Timor-Leste and Vietnam have RFR fractions, estimation for number of machines required can be obtained which will guide acquisition of machines in SEA countries. RFR is low with access varied based on the economic status. © 2018 John Wiley & Sons Australia, Ltd.

  8. SU-E-J-105: Stromal-Epithelial Responses to Fractionated Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Qayyum, M [Little Company of Mary Hospital, Ever Green Park, IL (United States)

    2014-06-01

    Purpose: The stromal-epithelial-cell interactions that are responsible for directing normal breast-tissue development and maintenance play a central role in the progression of breast cancer. In the present study, we developed three-dimensional (3-D) cell co-cultures used to study cancerous mammary cell responses to fractionated radiotherapy. In particular, we focused on the role of the reactive stroma in determining the therapeutic ratio for postsurgical treatment. Methods: Cancerous human mammary epithelial cells were cultured in a 3-D collagen matrix with human fibroblasts stimulated by various concentrations of transforming growth factor beta 1 (TGF-β1). These culture samples were designed to model the post-lumpectomy mammary stroma in the presence of residual cancer cells. We tracked over time the changes in medium stiffness, fibroblast-cell activation (conversion to cancer activated fibroblasts (CAF)), and proliferation of both cell types under a variety of fractionated radiotherapy protocols. Samples were exposed to 6 MV X-rays from a linear accelerator in daily fraction sizes of 90, 180 and 360 cGy over five days in a manner consistent with irradiation exposure during radiotherapy. Results: We found in fractionation studies with fibroblasts and CAF that higher doses per fraction may be more effective early on in deactivating cancer-harboring cellular environments. Higher-dose fraction schemes inhibit contractility in CAF and prevent differentiation of fibroblasts, thereby metabolically uncoupling tumor cells from their surrounding stroma. Yet, over a longer time period, the higher dose fractions may slow wound healing and increase ECM stiffening that could stimulate proliferation of surviving cancer cells. Conclusion: The findings suggest that dose escalation to the region with residual disease can deactivate the reactive stroma, thus minimizing the cancer promoting features of the cellular environment. Large-fraction irradiation may be used to sterilize

  9. SU-E-J-105: Stromal-Epithelial Responses to Fractionated Radiotherapy

    International Nuclear Information System (INIS)

    Qayyum, M

    2014-01-01

    Purpose: The stromal-epithelial-cell interactions that are responsible for directing normal breast-tissue development and maintenance play a central role in the progression of breast cancer. In the present study, we developed three-dimensional (3-D) cell co-cultures used to study cancerous mammary cell responses to fractionated radiotherapy. In particular, we focused on the role of the reactive stroma in determining the therapeutic ratio for postsurgical treatment. Methods: Cancerous human mammary epithelial cells were cultured in a 3-D collagen matrix with human fibroblasts stimulated by various concentrations of transforming growth factor beta 1 (TGF-β1). These culture samples were designed to model the post-lumpectomy mammary stroma in the presence of residual cancer cells. We tracked over time the changes in medium stiffness, fibroblast-cell activation (conversion to cancer activated fibroblasts (CAF)), and proliferation of both cell types under a variety of fractionated radiotherapy protocols. Samples were exposed to 6 MV X-rays from a linear accelerator in daily fraction sizes of 90, 180 and 360 cGy over five days in a manner consistent with irradiation exposure during radiotherapy. Results: We found in fractionation studies with fibroblasts and CAF that higher doses per fraction may be more effective early on in deactivating cancer-harboring cellular environments. Higher-dose fraction schemes inhibit contractility in CAF and prevent differentiation of fibroblasts, thereby metabolically uncoupling tumor cells from their surrounding stroma. Yet, over a longer time period, the higher dose fractions may slow wound healing and increase ECM stiffening that could stimulate proliferation of surviving cancer cells. Conclusion: The findings suggest that dose escalation to the region with residual disease can deactivate the reactive stroma, thus minimizing the cancer promoting features of the cellular environment. Large-fraction irradiation may be used to sterilize

  10. Stereotactic Fractionated Radiotherapy in the Treatment of Juxtapapillary Choroidal Melanoma: The McGill University Experience

    Energy Technology Data Exchange (ETDEWEB)

    Al-Wassia, Rolina; Dal Pra, Alan; Shun, Kitty; Shaban, Ahmed [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); Corriveau, Christine [Department of Ophthalmology, Notre Dame Hospital, Centre Hospitalier de l' Universite de Montreal, Montreal, Quebec (Canada); Edelstein, Chaim; Deschenes, Jean [Department of Ophthalmology, McGill University Health Centre, Montreal, Quebec (Canada); Ruo, Russel; Patrocinio, Horacio [Department of Medical Physics, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); Cury, Fabio L.B. [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada); DeBlois, Francois [Department of Medical Physics, Jewish General Hospital, McGill University, Montreal, Quebec (Canada); Shenouda, George, E-mail: george.shenouda@muhc.mcgill.ca [Department of Oncology, Division of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, Montreal, Quebec (Canada)

    2011-11-15

    Purpose: To report our experience with linear accelerator-based stereotactic fractionated radiotherapy in the treatment of juxtapapillary choroidal melanoma. Methods and Materials: We performed a retrospective review of 50 consecutive patients diagnosed with juxtapapillary choroidal melanoma and treated with linear accelerator-based stereotactic fractionated radiotherapy between April 2003 and December 2009. Patients with small to medium sized lesions (Collaborative Ocular Melanoma Study classification) located within 2 mm of the optic disc were included. The prescribed radiation dose was 60 Gy in 10 fractions. The primary endpoints included local control, enucleation-free survival, and complication rates. Results: The median follow-up was 29 months (range, 1-77 months). There were 31 males and 29 females, with a median age of 69 years (range, 30-92 years). Eighty-four percent of the patients had medium sized lesions, and 16% of patients had small sized lesions. There were four cases of local progression (8%) and three enucleations (6%). Actuarial local control rates at 2 and 5 years were 93% and 86%, respectively. Actuarial enucleation-free survival rates at 2 and 5 years were 94% and 84%, respectively. Actuarial complication rates at 2 and 5 years were 33% and 88%, respectively, for radiation-induced retinopathy; 9.3% and 46.9%, respectively, for dry eye; 12% and 53%, respectively, for cataract; 30% and 90%, respectively, for visual loss [Snellen acuity (decimal equivalent), <0.1]; 11% and 54%, respectively, for optic neuropathy; and 18% and 38%, respectively, for neovascular glaucoma. Conclusions: Linear accelerator-based stereotactic fractionated radiotherapy using 60 Gy in 10 fractions is safe and has an acceptable toxicity profile. It has been shown to be an effective noninvasive treatment for juxtapapillary choroidal melanomas.

  11. Intra-fraction motion of larynx radiotherapy

    Science.gov (United States)

    Durmus, Ismail Faruk; Tas, Bora

    2018-02-01

    In early stage laryngeal radiotherapy, movement is an important factor. Thyroid cartilage can move from swallowing, breathing, sound and reflexes. The effects of this motion on the target volume (PTV) during treatment were examined. In our study, the target volume movement during the treatment for this purpose was examined. Thus, setup margins are re-evaluated and patient-based PTV margins are determined. Intrafraction CBCT was scanned in 246 fractions for 14 patients. During the treatment, the amount of deviation which could be lateral, vertical and longitudinal axis was determined. ≤ ± 0.1cm deviation; 237 fractions in the lateral direction, 202 fractions in the longitudinal direction, 185 fractions in the vertical direction. The maximum deviation values were found in the longitudinal direction. Intrafraction guide in laryngeal radiotherapy; we are sure of the correctness of the treatment, the target volume is to adjust the margin and dose more precisely, we control the maximum deviation of the target volume for each fraction. Although the image quality of intrafraction-CBCT scans was lower than the image quality of planning CT, they showed sufficient contrast for this work.

  12. Reirradiation of brain and skull base tumors with fractionated stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Tokuuye, Koichi; Akine, Yasuyuki; Sumi, Minako; Kagami, Yoshikazu; Ikeda, Hiroshi; Oyama, Hiroshi; Inou, Yasushi; Shibui, Soichiro; Nomura, Kazuhiro

    1998-01-01

    Purpose: We evaluated the feasibility of fractionated stereotactic radiotherapy for small intracranial recurrences after conventional radiotherapy. Methods and Materials: Nineteen patients who had initially undergone conventional radiotherapy to intracranial lesions, receiving a median total dose of 50 Gy in 5 weeks, were retreated with stereotactic radiotherapy for their recurrences and received a median total dose of 42 Gy in seven fractions over 2.3 weeks. Results: Of the 19 patients, 15 achieved local control 3-51 months after reirradiation. No patient suffered from acute reaction, but one patient with a history of extensive radiotherapy developed progressive radionecrosis 9 months after reirradiation. Conclusions: Fractionated stereotactic radiotherapy of intracranial recurrences appears to be effective in achieving in local control with negligible morbidity. We believe it merits further investigation in a prospective study

  13. Evidence-based optimal number of radiotherapy fractions for cancer: A useful tool to estimate radiotherapy demand.

    Science.gov (United States)

    Wong, Karen; Delaney, Geoff P; Barton, Michael B

    2016-04-01

    The recently updated optimal radiotherapy utilisation model estimated that 48.3% of all cancer patients should receive external beam radiotherapy at least once during their disease course. Adapting this model, we constructed an evidence-based model to estimate the optimal number of fractions for notifiable cancers in Australia to determine equipment and workload implications. The optimal number of fractions was calculated based on the frequency of specific clinical conditions where radiotherapy is indicated and the evidence-based recommended number of fractions for each condition. Sensitivity analysis was performed to assess the impact of variables on the model. Of the 27 cancer sites, the optimal number of fractions for the first course of radiotherapy ranged from 0 to 23.3 per cancer patient, and 1.5 to 29.1 per treatment course. Brain, prostate and head and neck cancers had the highest average number of fractions per course. Overall, the optimal number of fractions was 9.4 per cancer patient (range 8.7-10.0) and 19.4 per course (range 18.0-20.7). These results provide valuable data for radiotherapy services planning and comparison with actual practice. The model can be easily adapted by inserting population-specific epidemiological data thus making it applicable to other jurisdictions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Stereotactic Fractionated Radiotherapy in the Treatment of Juxtapapillary Choroidal Melanoma: The McGill University Experience

    International Nuclear Information System (INIS)

    Al-Wassia, Rolina; Dal Pra, Alan; Shun, Kitty; Shaban, Ahmed; Corriveau, Christine; Edelstein, Chaim; Deschenes, Jean; Ruo, Russel; Patrocinio, Horacio; Cury, Fabio L.B.; DeBlois, François; Shenouda, George

    2011-01-01

    Purpose: To report our experience with linear accelerator-based stereotactic fractionated radiotherapy in the treatment of juxtapapillary choroidal melanoma. Methods and Materials: We performed a retrospective review of 50 consecutive patients diagnosed with juxtapapillary choroidal melanoma and treated with linear accelerator-based stereotactic fractionated radiotherapy between April 2003 and December 2009. Patients with small to medium sized lesions (Collaborative Ocular Melanoma Study classification) located within 2 mm of the optic disc were included. The prescribed radiation dose was 60 Gy in 10 fractions. The primary endpoints included local control, enucleation-free survival, and complication rates. Results: The median follow-up was 29 months (range, 1–77 months). There were 31 males and 29 females, with a median age of 69 years (range, 30–92 years). Eighty-four percent of the patients had medium sized lesions, and 16% of patients had small sized lesions. There were four cases of local progression (8%) and three enucleations (6%). Actuarial local control rates at 2 and 5 years were 93% and 86%, respectively. Actuarial enucleation-free survival rates at 2 and 5 years were 94% and 84%, respectively. Actuarial complication rates at 2 and 5 years were 33% and 88%, respectively, for radiation-induced retinopathy; 9.3% and 46.9%, respectively, for dry eye; 12% and 53%, respectively, for cataract; 30% and 90%, respectively, for visual loss [Snellen acuity (decimal equivalent), <0.1]; 11% and 54%, respectively, for optic neuropathy; and 18% and 38%, respectively, for neovascular glaucoma. Conclusions: Linear accelerator-based stereotactic fractionated radiotherapy using 60 Gy in 10 fractions is safe and has an acceptable toxicity profile. It has been shown to be an effective noninvasive treatment for juxtapapillary choroidal melanomas.

  15. Twice-a-day fractionated radiotherapy for head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kita, Midori [Tokyo Metropolitan Hospital of Fuchu (Japan)

    1996-12-01

    To improve the local control rate in radiotherapy for hand and neck cancer, several prospected twice-a-day fractionated radiotherapy (TDRF) were conducted in Tokyo Women`s Medical College. T2 glottic cancer was irradiated with 1.5 Gy/fraction, 2 fraction/day to a total dose of 72 Gy. Five cumulative local control rate was 88.2%. Locally advanced head and neck cancer was treated with TDFR and systemic chemotherapy. Response rate was 100%. Palliative radiotherapy with TDFR was done to relive from the pain and other symptoms for advanced and recurrent cases. Nine cases of 11 were relieved from the symptoms. These results was suggested the TDFR was useful to improve the local control rate. (author)

  16. Twice-a-day fractionated radiotherapy for head and neck cancer

    International Nuclear Information System (INIS)

    Kita, Midori

    1996-01-01

    To improve the local control rate in radiotherapy for hand and neck cancer, several prospected twice-a-day fractionated radiotherapy (TDRF) were conducted in Tokyo Women's Medical College. T2 glottic cancer was irradiated with 1.5 Gy/fraction, 2 fraction/day to a total dose of 72 Gy. Five cumulative local control rate was 88.2%. Locally advanced head and neck cancer was treated with TDFR and systemic chemotherapy. Response rate was 100%. Palliative radiotherapy with TDFR was done to relive from the pain and other symptoms for advanced and recurrent cases. Nine cases of 11 were relieved from the symptoms. These results was suggested the TDFR was useful to improve the local control rate. (author)

  17. Fractionated stereotactic radiotherapy in patients with acromegaly: an interim single-centre audit

    DEFF Research Database (Denmark)

    Roug, Anne Stidsholt; Rasmussen, Åse Krogh; Juhler, M

    2010-01-01

    To evaluate the effect of fractionated stereotactic radiotherapy (FSRT) in acromegaly in a retrospective analysis.......To evaluate the effect of fractionated stereotactic radiotherapy (FSRT) in acromegaly in a retrospective analysis....

  18. Evaluation of inter-fraction error during prostate radiotherapy

    International Nuclear Information System (INIS)

    Komiyama, Takafumi; Nakamura, Koji; Motoyama, Tsuyoshi; Onishi, Hiroshi; Sano, Naoki

    2008-01-01

    The purpose of this study was to evaluate inter-fraction error (inter-fraction set-up error+inter-fraction internal organ motion) between treatment planning and delivery during radiotherapy for localized prostate cancer. Twenty three prostate cancer patients underwent image-guided radical irradiation with the CT-linac system. All patients were treated in the supine position. After set-up with external skin markers, using CT-linac system, pretherapy CT images were obtained and isocenter displacement was measured. The mean displacement of the isocenter was 1.8 mm, 3.3 mm, and 1.7 mm in the left-right, ventral-dorsal, and cranial-caudal directions, respectively. The maximum displacement of the isocenter was 7 mm, 12 mm, and 9 mm in the left-right, ventral-dorsal, and cranial-caudal directions, respectively. The mean interquartile range of displacement of the isocenter was 1.8 mm, 3.7 mm, and 2.0 mm in the left-right, ventral-dorsal, and cranial-caudal directions, respectively. In radiotherapy for localized prostate cancer, inter-fraction error was largest in the ventral-dorsal directions. Errors in the ventral-dorsal directions influence both local control and late adverse effects. Our study suggested the set-up with external skin markers was not enough for radical radiotherapy for localized prostate cancer, thereby those such as a CT-linac system for correction of inter-fraction error being required. (author)

  19. A randomised controlled trial to evaluate both the role and the optimal fractionation of radiotherapy in the conservative management of early breast cancer.

    Science.gov (United States)

    Spooner, D; Stocken, D D; Jordan, S; Bathers, S; Dunn, J A; Jevons, C; Dodson, L; Morrison, J M; Oates, G D; Grieve, R J

    2012-12-01

    Postoperative radiotherapy is routinely used in early breast cancer employing either 50 Gy in 25 daily fractions (long course) or 40 Gy in 15 daily fractions (short course). The role of radiotherapy and shorter fractionation regimens require validation. Patients with clinical stage I and II disease were randomised to receive immediate radiotherapy or delayed salvage treatment (no radiotherapy). Patients receiving radiotherapy were further randomised between long (50 Gy in 25 daily fractions) or short (40 Gy in 15 daily fractions) regimens. The primary outcome measure was time to first locoregional relapse. Reported results are at a median follow-up of 16.9 years (interquartile range 15.4-18.8). In total, 707 women were recruited between 1985 and 1992: median age 59 years (range 28-80), 68% postmenopausal, median tumour size 2.0 cm (range 0.12-8.0); 271 patients have relapsed: 110 radiotherapy, 161 no radiotherapy. The site of first relapse was locoregional158 (64%) and distant 87 (36%). There was an estimated 24% reduction in the risk of any competing event (local relapse, distant relapse or death) with radiotherapy (hazard ratio = 0.76; 95% confidence interval 0.65, 0.88). The benefit of radiotherapy treatment for all competing event types was statistically significant (X(Wald)(2) = 36.04, P < 0.001). Immediate radiotherapy reduced the risk of locoregional relapse by 62% (hazard ratio = 0.38; 95% confidence interval 0.27, 0.53), consistent across prognostic subgroups. No differences were seen between either radiotherapy fractionation schedules. This study confirmed better locoregional control for patients with early breast cancer receiving radiotherapy. A radiotherapy schedule of 40 Gy in 15 daily fractions is an efficient and effective regimen that is at least as good as the international conventional regimen of 50 Gy in 25 daily fractions. Copyright © 2012. Published by Elsevier Ltd.

  20. Impact of radiation therapy fraction size on local control of early glottic carcinoma

    International Nuclear Information System (INIS)

    Yu, Edward; Shenouda, George; Beaudet, Marie P.; Black, Martin J.

    1997-01-01

    Purpose: Different radiotherapy fractionation schedules were used over a 10-year period to treat patients with early squamous cell carcinoma of the vocal cords at McGill University. A retrospective analysis was performed to study the effect of fraction size on local control in this group of patients. Methods and Materials: A total of 126 previously untreated patients with T1 invasive squamous cell carcinoma of the true vocal cords were irradiated between January 1978 and December 1988 in the Department of Radiation Oncology at McGill University. All patients received megavoltage irradiation, 94 patients received daily fractions > 2 Gy (64 patients received 50 Gy with once-daily 2.5-Gy fractions, and 30 received 65.25 Gy in 29 fractions of 2.25 Gy each), and 32 patients were treated to a dose of 66 Gy in 33 fractions with 2 Gy/fraction. Patients' characteristics of prognostic importance were equally distributed between the two fractionation groups. Results: At a median follow-up of 84 months, the 10-year disease-free survival and overall survival were 76% and 93%, respectively. Local control for patients treated with > 2 Gy fraction was 84%, compared to 65.6% for those treated with 2-Gy fractions (p = 0.026). Among the prognostic factors tested, such as gender, age, stage, anterior and posterior commissure involvement, smoking history, and fraction size, the latter was the only significant predictor of local control for the whole group of patients in univariate (p = 0.041) and multivariate (p = 0.023) analysis. There was no observed difference in the incidence of complications between the two fraction groups. Conclusions: From the results of this retrospective review of patients treated with radiotherapy for T1 true vocal cord cancer, and within the range of total doses and overall treatment times used in our patients, it was found that fractionation schedules using daily fraction size > 2 Gy are associated with a better local control than schedules delivering 2 Gy/fraction

  1. Palliative radiotherapy for painful bone metastases, single versus multiple fraction treatment: a literature review

    International Nuclear Information System (INIS)

    McKee, L.

    2005-01-01

    Palliative radiotherapy provides pain relief for patients with painful bone metastases. The practice among radiation oncologists as to whether a large single fraction is most effective, or whether multiple smaller fractions are preferable in providing the quickest, most durable pain relief is inconsistent. A literature review was completed to see if there is consensus about whether there is better pain response and control following single versus multiple fraction radiotherapy. The Pub Med search engine was used to find all reported studies comparing single and multiple fraction radiotherapy for painful bone metastases. Each article was reviewed according to specific criteria. A generalized conclusion was ascertained from each study and then compared. Among the studies reviewed, the consensus concluded that single fraction radiotherapy was the better choice for palliation of painful bone metastases. According to the literature reviewed, single fraction radiotherapy provides adequate pain relief with reasonable duration of pain response. (author)

  2. Impact of Fraction Size on Lung Radiation Toxicity: Hypofractionation may be Beneficial in Dose Escalation of Radiotherapy for Lung Cancers

    International Nuclear Information System (INIS)

    Jin Jinyue; Kong Fengming; Chetty, Indrin J.; Ajlouni, Munther; Ryu, Samuel; Ten Haken, Randall; Movsas, Benjamin

    2010-01-01

    Purpose: To assess how fraction size impacts lung radiation toxicity and therapeutic ratio in treatment of lung cancers. Methods and Materials: The relative damaged volume (RDV) of lung was used as the endpoint in the comparison of various fractionation schemes with the same normalized total dose (NTD) to the tumor. The RDV was computed from the biologically corrected lung dose-volume histogram (DVH), with an α/β ratio of 3 and 10 for lung and tumor, respectively. Two different (linear and S-shaped) local dose-effect models that incorporated the concept of a threshold dose effect with a single parameter D L50 (dose at 50% local dose effect) were used to convert the DVH into the RDV. The comparison was conducted using four representative DVHs at different NTD and D L50 values. Results: The RDV decreased with increasing dose/fraction when the NTD was larger than a critical dose (D CR ) and increased when the NTD was less than D CR . The D CR was 32-50 Gy and 58-87 Gy for a small tumor (11 cm 3 ) for the linear and S-shaped local dose-effect models, respectively, when D L50 was 20-30 Gy. The D CR was 66-97 Gy and 66-99 Gy, respectively, for a large tumor (266 cm 3 ). Hypofractionation was preferred for small tumors and higher NTDs, and conventional fractionation was better for large tumors and lower NTDs. Hypofractionation might be beneficial for intermediate-sized tumors when NTD = 80-90 Gy, especially if the D L50 is small (20 Gy). Conclusion: This computational study demonstrated that hypofractionated stereotactic body radiotherapy is a better regimen than conventional fractionation in lung cancer patients with small tumors and high doses, because it generates lower RDV when the tumor NTD is kept unchanged.

  3. Altered fractionated radiotherapy has a survival benefit for head and neck cancers. Is it true?

    International Nuclear Information System (INIS)

    Hatano, Kazuo; Sakai, Mitsuhiro; Araki, Hitoshi; Doi, Katsuyuki; Asano, Takanori; Fujikawa, Akira

    2007-01-01

    There was a significant survival benefit with altered fractionated radiotherapy, corresponding to an absolute benefit of 3.4% at 5 years. The benefit was significantly higher with hyperfractionated radiotherapy (8% at 5 years) than with accelerated radiotherapy (2% with accelerated fractionation without total dose reduction and 1.7% with total dose reduction at 5 years). The effect was greater for the primary tumor than for nodal disease. The effect was also more pronounced in younger patients and in those with good performance status. Hyperfractionation seemed to yield a more consistent advantage for survival than accelerated fractionated radiotherapy. However, accelerated radiotherapy might be associated with higher non-cancer related death. We have to evaluate whether the benefit of hyperfractionated radiotherapy versus standard radiotherapy persists when combined with concomitant chemotherapy and the benefit of intensity-modulated radiation therapy (IMRT) compared with altered fractionation. (author)

  4. Role of tumor size in radiotherapy using modifiers

    International Nuclear Information System (INIS)

    Kozin, S.V.; Furmanchuk, A.V.

    1990-01-01

    Consideration is given to present-day knowledge about changes, taking place in malignant tumor tissues during their growth, important for results of radiotherapy, using modifiers, from a radiobiological viewpoint. It is shown that hypertermia (HT) is the most effective adjuvant of radiotherapy for medium - and large-size tumors. The combined application of artificial hyperglycemia (AH) and HT is investigated as the method for increasing efficiency of radiotherapy. Efficiency of using radioprotectors and electron-acceptor compounds (metronidazole, misonidazole) for large-size malignant tumors in combinations-metronidazole with AH and misonidazole with HT-is noted. Analysis of these data on radiotherapy efficiency depending on size of irradiated tumors will enable an evaluation of radiotherapy potential in different cases in determining the advisability of modifier application

  5. Radiobiologically based assessments of the net costs of fractionated radiotherapy

    International Nuclear Information System (INIS)

    Dale, Roger G.; Jones, Bleddyn

    1996-01-01

    Purpose: To examine how the long-term costs of radiation therapy may be influenced by modifications to fractionation schemes, and how any improvements in tumor control might, in principle, be translated into a potential cost saving for the responsible healthcare organization. Methods and Materials: Standard radiobiological modeling based on the linear-quadratic (LQ) model is combined with financial parameters relating to the estimated costs of different aspects of radiotherapy treatment delivery. The cost model includes provision for the long-term costs of treatment failure and enables the extra costs of near optimal radiotherapy to be balanced against suboptimal alternatives, which are more likely to be associated with further radiotherapy, salvage surgery, and continuing care. Results: A number of caveats are essential in presenting a model such as this for the first time, and these are clearly stated. However, a recurring observation is that, in terms of the whole cost of supporting a patient from first radiotherapy treatment onwards, high quality radiotherapy (i.e., based on individual patterns of fractionation that are near optimal for particular subpopulations of tumor) will frequently be associated with the lowest global cost. Conclusions: This work adds weight to the case for identifying fast and accurate predictive assay techniques, and supports the argument that suboptimal radiotherapy is usually more costly in the long term. Although the article looks only at the cost-benefit consequences of altered patterns of fractionation, the method will, in principle, have application to other changes in the way radiotherapy can be performed, e.g., to examining the cost-benefit aspects of tumor dose escalation as a consequence of using advanced conformal treatment planning

  6. Fractionated stereotactic radiotherapy for craniopharyngiomas

    International Nuclear Information System (INIS)

    Schulz-Ertner, Daniela; Frank, Claudia; Herfarth, Klaus K.; Rhein, Bernhard; Wannenmacher, Michael; Debus, Juergen

    2002-01-01

    Purpose: To investigate outcome and toxicity after fractionated stereotactic radiation therapy (FSRT) in patients with craniopharyngiomas. Methods and Materials: Twenty-six patients with craniopharyngiomas were treated with FSRT between May 1989 and February 2001. Median age was 33.5 years (range: 5-57 years). Nine patients received FSRT after surgery as primary treatment, and 17 patients were irradiated for recurrent tumor or progressive growth after initial surgery. Median target dose was 52.2 Gy (range: 50.0-57.6 Gy) with conventional fractionation. Follow-up included MRI and neurologic, ophthalmologic, and endocrinologic examinations. Results: The median follow-up was 43 months (range: 7-143 months). The actuarial local control rate and actuarial overall survival rates were 100% and 100%, respectively, at 5 years and 100% and 83%, respectively, at 10 years. Four patients showed complete response, 14 patients showed partial response, and 8 patients remained stable. In 5 patients, vision improved after radiation therapy. Acute toxicity was mild. One patient required cyst drainage 3 months after radiotherapy. Late toxicity after radiotherapy included impairment of hormone function in 3 out of 18 patients at risk. We did not observe any vision impairment, radionecrosis, or secondary malignancies. Conclusions: FSRT is effective and safe in the treatment of cystic craniopharyngiomas. Toxicity is extremely low using this conformal technique

  7. Adjuvant single-fraction radiotherapy is safe and effective for intractable keloids

    International Nuclear Information System (INIS)

    Song, Changhoon; Wu, Honggyun; Chang, Hak; Kim, Il Han; Ha, Sung W.

    2014-01-01

    The aim of this study was to assess the feasibility and efficacy of high-dose, single-fraction electron beam radiotherapy for therapy-resistant keloids. Before 2010, intractable keloids were treated at our institution with post-operative irradiation of 6-15 Gy in 3-5 fractionations. For convenience and cost effectiveness, we have changed our treatment protocol to high-dose single-fraction radiotherapy. A total of 12 patients with 16 keloid lesions were treated from January 2010 to January 2013 in our department. A 10-Gy dose of electron irradiation was given within 72 h of the surgical excision. The mean follow-up period was 20 months. Treatments were well tolerated, and there was no recurrence in any of the patients. Severe adverse effects were not observed. Surgical excision of the keloid, followed by immediate, single-fraction, high-dose radiotherapy, is both safe and effective in preventing recurrence of therapy-resistant keloids. (author)

  8. Late course accelerated fractionation in radiotherapy of esophageal carcinoma

    International Nuclear Information System (INIS)

    Shi, X.-H.; Yao, W.; Liu, T.

    1999-01-01

    Purpose: To evaluate the efficacy of adding accelerated fractionation after completing two thirds of routine fractionated radiotherapy in esophageal carcinoma.Methods and materials: From April 1988 to April 1990, 85 patients with histologically confirmed carcinoma of the esophagus were randomized into two groups. (1) The conventional fractionation (CF) group, received 1.8 Gy per day five times a week to a total dose of 68.4 Gy in 7-8 weeks, and (2) the late course accelerated hyperfractionated (LCAF) group which received the same schedule as the CF group during the first two thirds of the course of radiotherapy to a dose of 41.4 Gy/23 fx/4 to 5 weeks. This was then followed by accelerated hyperfractionation using reduced fields. In the LCAF portion of the radiotherapeutic course, the irradiation schedule was changed to 1.5 Gy twice a day, with an interval of 4 h between fractions, to a dose of 27 Gy/18 fx. Thus the total dose was also 68.4 Gy, the same as the CF group, but the course of radiotherapy was shorter, being only 6.4 weeks. The same Cobalt 60 teletherapy unit was used to treat all the cases.Results: The 5 year actuarial survival and disease-free survival rates in the LCAF group were 34% and 42%, as compared to 15% and 15% respectively in the CF group, all statistically significant. Better local control was seen in the LCAF group than in the CF group, the 5 year control rates being 55% versus 21% (P=0.003). The acute reactions were increased but acceptable in the LCAF patients, the radiation treatments could be completed without any breaks. The late reactions as observed after 5 years were not increased in comparison with the CF patients.Conclusions: The results from this study show that the late course accelerated hyperfractionated radiotherapy regime can improve results in esophageal carcinoma, with acceptable acute reactions as compared to conventional radiotherapy. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. Parotid gland function following accelerated and conventionally fractionated radiotherapy

    International Nuclear Information System (INIS)

    Leslie, M.D.; Dische, S.

    1991-01-01

    The function of parotid glands in patients treated by 3 different schedules of radiotherapy was studied 9 months or more after its conclusion. All had received radiotherapy for a malignancy confined to 1 side of the head and neck region and only the gland on the side of the lesion was in the treatment volume; the contralateral gland acted as an internal control. Saliva was selectively collected from the parotid glands and the stimulated flow rate and pH of the saliva determined. Flow rates were expressed in each case as a percentage of that of the contralateral ('untreated') gland. Twelve glands that had received conventionally fractionated radiotherapy to a dose of 60-66 Gy showed a mean percentage flow of 20 percent and a significant fall in the pH of the saliva produced. Six glands that had received CHART (Continuous Hyperfractionated Accelerated RadioTherapy) and 8 conventionally fractionated radiotherapy to a dose of 35-40 Gy showed mean percentage flows of 57 and 65 percent respectively, with only slight and non-significant falls in saliva pH. The results show that in the treatment of squamous cell carcinoma in the head and neck the use of CHART can lead to considerable less late change in the function of the parotid gland. (author). 26 refs.; 5 figs.; 2 tabs

  10. Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54-56 Gy given in 9-7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size.

    Science.gov (United States)

    Aoki, Masahiko; Sato, Mariko; Hirose, Katsumi; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Ono, Shuichi; Takai, Yoshihiro

    2015-04-22

    Radiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor. During 2003-2008, 41 patients with 42 lung tumors were treated with SBRT to 54-56 Gy in 9-7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study. Median follow-up time was 68 months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16-48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54 Gy were 47.7% and 12.9% (p = 0.0184), and for fraction size of 6, 7 and 8 Gy were 19.5%, 31.2% and 55.7% (p = 0.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10-55, age, sex, and planning target volume were not significantly different. The doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures.

  11. Estimation of the optimal number of radiotherapy fractions for breast cancer: A review of the evidence.

    Science.gov (United States)

    Wong, Karen; Delaney, Geoff P; Barton, Michael B

    2015-08-01

    There is variation in radiotherapy fractionation practice, however, there is no evidence-based benchmark for appropriate activity. An evidence-based model was constructed to estimate the optimal number of fractions for the first course of radiotherapy for breast cancer to aid in services planning and performance benchmarking. The published breast cancer radiotherapy utilisation model was adapted. Evidence-based number of fractions was added to each radiotherapy indication. The overall optimal number of fractions was calculated based on the frequency of specific clinical conditions where radiotherapy is indicated and the recommended number of fractions for each condition. Sensitivity analysis was performed to assess the impact of uncertainties on the model. For the entire Australian breast cancer patient population, the estimated optimal number of fractions per patient was 16.8, 14.6, 13.7 and 0.8 for ductal carcinoma in situ, early, advanced and metastatic breast cancer respectively. Overall, the optimal number of fractions per patient was 14.4 (range 14.4-18.7). These results allow comparison with actual practices, and workload prediction to aid in services planning. The model can be easily adapted to other countries by inserting population-specific epidemiological data, and to future changes in cancer incidence, stage distribution and fractionation recommendations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Consideration of margins for hypo fractionated radiotherapy

    International Nuclear Information System (INIS)

    Herschtal, A.; Foroudi, F.; Kron, T.

    2010-01-01

    Full text: Geographical misses of the tumour are of concern in radiotherapy and are typically accommodated by introducing margins around the target. However, there is a trade-off between ensuring the target receives sufficient dose and minimising the dose to surrounding normal structures. Several methods of determining margin width have been developed with the most commonly used one proposed by M. VanHerk (VanHerk UROBP 52: 1407, 2002). VanHerk's model sets margins to achieve 95% of dose coverage for the target in 90% of patients. However, this model was derived assuming an infinite number of fractions. The aim of the present work is to estimate the modifications necessary to the model if a finite number of fractions are given. Software simulations were used to determine the true probability of a patient achieving 95% target coverage if different fraction numbers are used for a given margin width. Model parameters were informed by a large data set recently acquired at our institution using daily image guidance for prostate cancer patients with implanted fiducial markers. Assuming a 3 mm penumbral width it was found that using the VanHerk model only 74 or 54% of patients receive 95% of the prescription dose if 20 or 6 fractions are given, respectively. The steep dose gradients afforded by IMRT are likely to make consideration of the effects of hypofractionation more important. It is necessary to increase the margins around the target to ensure adequate tumour coverage if hypofractionated radiotherapy is to be used for cancer treatment. (author)

  13. Initial experience of single fraction radiotherapy (8 Gy x 1) in the treatment of painful bone metastases

    International Nuclear Information System (INIS)

    Amano, Kosuke; Ikeda, Hiroko; Chigusa, Satoshi; Tanaka, Masahiro; Katayama, Hirofumi; Takeda, Koji

    2014-01-01

    Sixteen patients with painful bone metastases received single fraction radiotherapy of 8 Gy. Single fraction radiotherapy was effective in providing pain relief with response rate of 88.8%. There were no severe acute side effects. The therapeutic regimen was also safe and effective in patients with poor performance status and poor prognosis. Therefore single fraction radiotherapy should be considered to treat pain arising from bone metastases. (author)

  14. Re-irradiation of recurrent anaplastic ependymoma using radiosurgery or fractionated stereotactic radiotherapy.

    Science.gov (United States)

    Murai, Taro; Sato, Kengo; Iwabuchi, Michio; Manabe, Yoshihiko; Ogino, Hiroyuki; Iwata, Hiromitsu; Tatewaki, Koshi; Yokota, Naoki; Ohta, Seiji; Shibamoto, Yuta

    2016-03-01

    Recurrent ependymomas were retreated with stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (FSRT). The efficacy, toxicities, and differences between SRS and FSRT were analyzed. Eight patients with recurrent ependymomas fulfilling the criteria described below were evaluated. Inclusion criteria were: (1) the patient had previously undergone surgery and conventional radiotherapy as first-line treatment; (2) targets were located in or adjacent to the eloquent area or were deep-seated; and (3) the previously irradiated volume overlapped the target lesion. FSRT was delivered to 18 lesions, SRS to 20 lesions. A median follow-up period was 23 months. The local control rate was 76 % at 3 years. No significant differences in local control were observed due to tumor size or fractionation schedule. Lesions receiving >25 Gy/5 fr or 21 Gy/3 fr did not recur within 1 year, whereas no dose-response relationship was observed in those treated with SRS. No grade ≥2 toxicity was observed. Our treatment protocol provided an acceptable LC rate and minimal toxicities. Because local recurrence of tumors may result in patient death, a minimum dose of 21 Gy/3 fr or 25 Gy/5 fr or higher may be most suitable for treatment of these cases.

  15. Role of fractionated radiotherapy in patients with hemangioma of the cavernous sinus

    International Nuclear Information System (INIS)

    Park, Sun Min; Yoon, Sang Min; Lee, Su Min; Park, Jin Hong; Song, Si Yeol; Lee, Sang Wook; Ahn, Seung Do; Kim, Jong Hoon; Choi, Eun Kyung

    2017-01-01

    We performed this retrospective study to investigate the outcomes of patients with hemangioma of the cavernous sinus after fractionated radiotherapy. We analyzed 10 patients with hemangioma of the cavernous sinus who were treated with conventional radiotherapy between January 2000 and December 2016. The median patient age was 54 years (range, 31–65 years), and 8 patients (80.0%) were female. The mean hemangioma volume was 34.1 cm"3 (range, 6.8–83.2 cm"3), and fractionated radiation was administered to a total dose of 50–54 Gy with a daily dose of 2 Gy. The median follow-up period was 6.8 years (range, 2.2–8.8 years). At last follow-up, the volume of the tumor had decreased in all patients. The average tumor volume reduction rate from the initial volume was 72.9% (range, 18.9–95.3%). All 10 of the cranial neuropathies observed before radiation therapy had improved, with complete symptomatic remission in 9 cases (90%) and partial remission in 1 case (10%). No new acute neurologic impairments were reported after radiotherapy. One probable compressive optic neuropathy was observed at 1 year after radiotherapy. Fractionated radiotherapy achieves both symptomatic and radiologic improvements. It is a well-tolerated treatment modality for hemangiomas of the cavernous sinus

  16. Role of fractionated radiotherapy in patients with hemangioma of the cavernous sinus

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Min; Yoon, Sang Min; Lee, Su Min; Park, Jin Hong; Song, Si Yeol; Lee, Sang Wook; Ahn, Seung Do; Kim, Jong Hoon; Choi, Eun Kyung [Dept. of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2017-09-15

    We performed this retrospective study to investigate the outcomes of patients with hemangioma of the cavernous sinus after fractionated radiotherapy. We analyzed 10 patients with hemangioma of the cavernous sinus who were treated with conventional radiotherapy between January 2000 and December 2016. The median patient age was 54 years (range, 31–65 years), and 8 patients (80.0%) were female. The mean hemangioma volume was 34.1 cm{sup 3} (range, 6.8–83.2 cm{sup 3}), and fractionated radiation was administered to a total dose of 50–54 Gy with a daily dose of 2 Gy. The median follow-up period was 6.8 years (range, 2.2–8.8 years). At last follow-up, the volume of the tumor had decreased in all patients. The average tumor volume reduction rate from the initial volume was 72.9% (range, 18.9–95.3%). All 10 of the cranial neuropathies observed before radiation therapy had improved, with complete symptomatic remission in 9 cases (90%) and partial remission in 1 case (10%). No new acute neurologic impairments were reported after radiotherapy. One probable compressive optic neuropathy was observed at 1 year after radiotherapy. Fractionated radiotherapy achieves both symptomatic and radiologic improvements. It is a well-tolerated treatment modality for hemangiomas of the cavernous sinus.

  17. Radiation-induced rib fracture after stereotactic body radiotherapy with a total dose of 54–56 Gy given in 9–7 fractions for patients with peripheral lung tumor: impact of maximum dose and fraction size

    International Nuclear Information System (INIS)

    Aoki, Masahiko; Sato, Mariko; Hirose, Katsumi; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Ono, Shuichi; Takai, Yoshihiro

    2015-01-01

    Radiation-induced rib fracture after stereotactic body radiotherapy (SBRT) for lung cancer has been recently reported. However, incidence of radiation-induced rib fracture after SBRT using moderate fraction sizes with a long-term follow-up time are not clarified. We examined incidence and risk factors of radiation-induced rib fracture after SBRT using moderate fraction sizes for the patients with peripherally located lung tumor. During 2003–2008, 41 patients with 42 lung tumors were treated with SBRT to 54–56 Gy in 9–7 fractions. The endpoint in the study was radiation-induced rib fracture detected by CT scan after the treatment. All ribs where the irradiated doses were more than 80% of prescribed dose were selected and contoured to build the dose-volume histograms (DVHs). Comparisons of the several factors obtained from the DVHs and the probabilities of rib fracture calculated by Kaplan-Meier method were performed in the study. Median follow-up time was 68 months. Among 75 contoured ribs, 23 rib fractures were observed in 34% of the patients during 16–48 months after SBRT, however, no patients complained of chest wall pain. The 4-year probabilities of rib fracture for maximum dose of ribs (Dmax) more than and less than 54 Gy were 47.7% and 12.9% (p = 0.0184), and for fraction size of 6, 7 and 8 Gy were 19.5%, 31.2% and 55.7% (p = 0.0458), respectively. Other factors, such as D2cc, mean dose of ribs, V10–55, age, sex, and planning target volume were not significantly different. The doses and fractionations used in this study resulted in no clinically significant rib fractures for this population, but that higher Dmax and dose per fraction treatments resulted in an increase in asymptomatic grade 1 rib fractures

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

    International Nuclear Information System (INIS)

    Zachariah, B.; Jacob, S.S.; Gwede, C.; Cantor, A.; Patil, J.; Casey, L.; Zachariah, A.B.

    2001-01-01

    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

  19. Quality assurance in fractionated stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Warrington, A.P.; Laing, R.W.; Brada, M.

    1994-01-01

    The recent development of fractionated stereotactic radiotherapy (SRT), which utilises the relocatable Gill-Thomas-Cosman frame (GTC 'repeat localiser'), requires comprehensive quality assurance (QA). This paper focuses on those QA procedures particularly relevant to fractionated SRT treatments, and which have been derived from the technique used at the Royal Marsden Hospital. They primarily relate to the following: (i) GTC frame fitting, initially in the mould room, and then at each imaging session and treatment fraction; (ii) checking of the linear accelerator beam geometry and alignment lasers; and (iii) setting up of the patient for each fraction of treatment. The precision of the fractionated technique therefore depends on monitoring the GTC frame relocation at each fitting, checking the accuracy of the radiation isocentre of the treatment unit, its coincidence with the patient alignment lasers and the adjustments required to set the patient up accurately. The results of our quality control checks show that setting up to a mean radiation isocentre using precisely set-up alignment lasers can be achievable to within 1 mm accuracy. When this is combined with a mean GTC frame relocatability of 1 mm on the patient, a 2-mm allowance between the prescribed isodose surface and the defined target volume is a realistic safety margin for this technique

  20. Hypo fractionated radiotherapy in advanced lung cancer

    International Nuclear Information System (INIS)

    Andrade Carvalho, Heloisa de; Saito, Newton Heitetsu; Gomes, Herbeni Cardoso; Aguilar, Patricia Bailao; Nadalin, Wladimir

    1996-01-01

    Patients with advanced lung cancers have bad prognosis and, many times, are submitted to prolonged and not always efficient treatments. We present a study where 51 patients were treated with hypo fractionated radiotherapy, based on two distinct schemes, according to the performance status and social conditions of each patient: continuous treatment: 30 Gy, 10 fractions of 3 Gy, 5 days/week (37 cases); weekly treatment: 30 Gy, 6 fractions of 5 Gy, once a week (14 cases). Symptoms relief and impact in survival were evaluated. In both groups, we observed improvement of symptoms in about 70% of the occurrences with a medium survival of three months. We conclude that hypo fractionation is an effective palliative treatment for lung cancers, in patients with short life-expectancy and must be considered as a option in advanced cases, in patients with short life-expectancy that deserve some kind of treatment. (author). 37 refs., 2 tabs

  1. Optimization of fractionated radiotherapy of tumors

    International Nuclear Information System (INIS)

    Ivanov, V.K.

    1984-01-01

    Underlying modern conceptions of clinical radiobiology and mathematic methods in system theory a model of radiation therapy for tumors is developed. To obtain optimal fractionating conditions the principle of gradual optimization is used. A optimal therapeutic method permits to minimize the survival of a tumor cell population with localized lesions of the intact tissue. An analytic research is carried out for the simplest variant of the model. By help of a SORT-program unit the conditions are ascertained for gradual optimization of radiotherapy. (author)

  2. A proliferation saturation index to predict radiation response and personalize radiotherapy fractionation

    International Nuclear Information System (INIS)

    Prokopiou, Sotiris; Moros, Eduardo G.; Poleszczuk, Jan; Caudell, Jimmy; Torres-Roca, Javier F.; Latifi, Kujtim; Lee, Jae K.; Myerson, Robert; Harrison, Louis B.; Enderling, Heiko

    2015-01-01

    Although altered protocols that challenge conventional radiation fractionation have been tested in prospective clinical trials, we still have limited understanding of how to select the most appropriate fractionation schedule for individual patients. Currently, the prescription of definitive radiotherapy is based on the primary site and stage, without regard to patient-specific tumor or host factors that may influence outcome. We hypothesize that the proportion of radiosensitive proliferating cells is dependent on the saturation of the tumor carrying capacity. This may serve as a prognostic factor for personalized radiotherapy (RT) fractionation. We introduce a proliferation saturation index (PSI), which is defined as the ratio of tumor volume to the host-influenced tumor carrying capacity. Carrying capacity is as a conceptual measure of the maximum volume that can be supported by the current tumor environment including oxygen and nutrient availability, immune surveillance and acidity. PSI is estimated from two temporally separated routine pre-radiotherapy computed tomography scans and a deterministic logistic tumor growth model. We introduce the patient-specific pre-treatment PSI into a model of tumor growth and radiotherapy response, and fit the model to retrospective data of four non-small cell lung cancer patients treated exclusively with standard fractionation. We then simulate both a clinical trial hyperfractionation protocol and daily fractionations, with equal biologically effective dose, to compare tumor volume reduction as a function of pretreatment PSI. With tumor doubling time and radiosensitivity assumed constant across patients, a patient-specific pretreatment PSI is sufficient to fit individual patient response data (R 2 = 0.98). PSI varies greatly between patients (coefficient of variation >128 %) and correlates inversely with radiotherapy response. For this study, our simulations suggest that only patients with intermediate PSI (0.45–0.9) are

  3. Patient costs associated with external beam radiotherapy treatment for localized prostate cancer: the benefits of hypofractionated over conventionally fractionated radiotherapy.

    Science.gov (United States)

    Sethukavalan, Perakaa; Cheung, Patrick; Tang, Colin I; Quon, Harvey; Morton, Gerard; Nam, Robert; Loblaw, Andrew

    2012-04-01

    To estimate the out-of-pocket costs for patients undergoing external beam radiotherapy (EBRT) for prostate cancer and calculate the patient-related savings of being treated with a 5-fraction versus a standard 39-fraction approach. Seventy patients accrued to the pHART3 (n = 84) study were analyzed for out-of-pocket patient costs as a result of undergoing treatment. All costs are in Canadian dollars. Using the postal code of the patient's residence, the distance between the hospital and patient home was found using Google Maps. The Canada Revenue Agency automobile allowance rate was then applied to determine the cost per kilometer driven. The average cost of travel from the hospital and pHART3 patient's residence was $246 per person after five trips. In a standard fractionation regimen, pHART3 patients would have incurred an average cost of $1921 after 39 visits. The patients receiving hypofractionated radiotherapy would have paid an average of $38 in parking while those receiving conventional treatment would have paid $293. The difference in out-of-pocket costs for the patients receiving a standard versus hypofractionated treatment was $1930. Medium term prospective data shows that hypofractionated radiotherapy is an effective treatment method for localized prostate cancer. Compared to standard EBRT, hypofractionated radiotherapy requires significantly fewer visits. Due to the long distance patients may have to travel to the cancer center and the expense of parking, the short course treatment saves each patient an average of $1900. A randomized study of standard versus hypofractionated accelerated radiotherapy should be conducted to confirm a favorable efficacy and tolerability profile of the shorter fractionation scheme.

  4. Not traditional regimes of radiotherapeutic dose fractionation as modifier of radiotherapy for carcinoma of lungs

    International Nuclear Information System (INIS)

    Artemova, N.A.

    2008-01-01

    The efficiency of applying various of radiotherapeutic dose fractionation was analyzed. The results of the own studies performed at the Scientific and Research Institute of Oncology and Medical Radiology for elaborating not traditional regimes of radiotherapeutic dose fractionation (a dynamic fractionation applying enlarged regimes at the first stage and the classic ones at the second stage) were presented. Appliance of the modified radiotherapy for the epidermoid carcinoma of the lungs allowed to increase the objective response from 45,3+-3% to 80+-5% the tumor disappearing completely in 40+-6% of patients as compared with 10+-2%. Appliance of the intensive not traditional variant of the radiotherapy dynamic fractionation in case of a small cell carcinoma of the lungs resulted in the therapy duration reduction from 6 to 4 weeks. Thus the not traditional dose fractionation might become a mechanism for the improving the radiotherapy of persons suffering from the carcinoma of the lungs. (authors)

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

    International Nuclear Information System (INIS)

    Cho, Jae Ho; Kim, Hyun Chang; Suh, Chang Ok

    2005-01-01

    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 ∼ 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∼ 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 (α / β = 10) and late-responding tissues (α /β = 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 3 and the risk of complication was assessed using serial multiple logistic regressions models. The associations between R-BED Gy 3 and rectal complications

  6. Visual Outcome in Meningiomas Around Anterior Visual Pathways Treated With Linear Accelerator Fractionated Stereotactic Radiotherapy

    International Nuclear Information System (INIS)

    Stiebel-Kalish, Hadas; Reich, Ehud; Gal, Lior; Rappaport, Zvi Harry; Nissim, Ouzi; Pfeffer, Raphael; Spiegelmann, Roberto

    2012-01-01

    Purpose: Meningiomas threatening the anterior visual pathways (AVPs) and not amenable for surgery are currently treated with multisession stereotactic radiotherapy. Stereotactic radiotherapy is available with a number of devices. The most ubiquitous include the gamma knife, CyberKnife, tomotherapy, and isocentric linear accelerator systems. The purpose of our study was to describe a case series of AVP meningiomas treated with linear accelerator fractionated stereotactic radiotherapy (FSRT) using the multiple, noncoplanar, dynamic conformal rotation paradigm and to compare the success and complication rates with those reported for other techniques. Patients and Methods: We included all patients with AVP meningiomas followed up at our neuro-ophthalmology unit for a minimum of 12 months after FSRT. We compared the details of the neuro-ophthalmologic examinations and tumor size before and after FSRT and at the end of follow-up. Results: Of 87 patients with AVP meningiomas, 17 had been referred for FSRT. Of the 17 patients, 16 completed >12 months of follow-up (mean 39). Of the 16 patients, 11 had undergone surgery before FSRT and 5 had undergone FSRT as first-line management. Tumor control was achieved in 14 of the 16 patients, with three meningiomas shrinking in size after RT. Two meningiomas progressed, one in an area that was outside the radiation field. The visual function had improved in 6 or stabilized in 8 of the 16 patients (88%) and worsened in 2 (12%). Conclusions: Linear accelerator fractionated RT using the multiple noncoplanar dynamic rotation conformal paradigm can be offered to patients with meningiomas that threaten the anterior visual pathways as an adjunct to surgery or as first-line treatment, with results comparable to those reported for other stereotactic RT techniques.

  7. Better compliance with hypofractionation vs. conventional fractionation in adjuvant breast cancer radiotherapy. Results of a single, institutional, retrospective study

    International Nuclear Information System (INIS)

    Rudat, Volker; Nour, Alaa; Hammoud, Mohamed; Abou Ghaida, Salam

    2017-01-01

    The aim of the study was to identify factors significantly associated with the occurrence of unintended treatment interruptions in adjuvant breast cancer radiotherapy. Patients treated with postoperative radiotherapy of the breast or chest wall between March 2014 and August 2016 were evaluated. The radiotherapy regimens and techniques applied were either conventional fractionation (CF; 28 daily fractions of 1.8 Gy or 25 fractions of 2.0 Gy) or hypofractionation (HF; 15 daily fractions of 2.67 Gy) with inverse planned intensity-modulated radiotherapy (IMRT) or three-dimensional planned conformal radiotherapy (3DCRT). Logistic regression analysis was used to identify factors associated with noncompliance. Noncompliance was defined as the missing of at least one scheduled radiotherapy fraction. In all, 19 of 140 (13.6%) patients treated with HF and 39 of 146 (26.7%) treated with CF experienced treatment interruptions. Of 23 factors tested, the fractionation regimen emerged as the only independent significant prognostic factor for noncompliance on multivariate analysis (CF; p = 0.007; odds ratio, 2.3; 95% confidence interval, 1.3-4.2). No statistically significant differences concerning the reasons for treatment interruptions could be detected between patients treated with CF or HF. HF is significantly associated with a better patient compliance with the prescribed radiotherapy schedule compared with CF. The data suggest that this finding is basically related to the shorter overall treatment time of HF. (orig.) [de

  8. Concurrent radiotherapy and carboplatin in non small-cell lung cancer: a pilot study using conventional and accelerated fractionation

    International Nuclear Information System (INIS)

    Ball, D.; Bishop, J.; Crennan, E.; Olver, I.

    1991-01-01

    Thirteen patients with unresectable non small cell lung cancer were treated with radical radiotherapy and carboplatin administered in order to ascertain the toxicity of concurent carboplatin/radiotherapy. The first 6 patients were treated to a total dose of 60 Gy in 30 fractions in 6 weeks, with carboplatin 70 mg/m 2 /day on days 1 to 5 during weeks 1 and 5 of radiotherapy. The remaining 7 patients were given 60 Gy in 30 fractions in 3 weeks, treating twice a day (accelerated fractionation). Carboplatin was given as above but only during week 1 of radiotherapy. Twelve patients completed radiotherapy without interruption but 2 patients developed grade 3 neutropenia. Major toxicity was oesophagitis, one patient requiring nasogastric feeding. Average duration of dysphagia (any grade) in the accelerated fractionation group was 21 weeks. Four patients achieved good partial responses even though initial tumour volume was large. It is concluded that this treatment is associated with increased but acceptable early mucosal toxicity. 6 refs., 1 tab., 1 fig

  9. Evaluation of oxygenation status during fractionated radiotherapy in human nonsmall cell lung cancers using [F-18]fluoromisonidazole positron emission tomography

    International Nuclear Information System (INIS)

    Wui-Jin, Koh; Bergman, Kenneth S.; Rasey, Janet S.; Peterson, Lanell M.; Evans, Margaret L.; Graham, Michael M.; Grierson, John R.; Lindsley, Karen L.; Lewellen, Thomas K.; Krohn, Kenneth A.; Griffin, Thomas W.

    1995-01-01

    Purpose: Recent clinical investigations have shown a strong correlation between pretreatment tumor hypoxia and poor response to radiotherapy. These observations raise questions about standard assumptions of tumor reoxygenation during radiotherapy, which has been poorly studied in human cancers. Positron emission tomography (PET) imaging of [F-18]fluoromisonidazole (FMISO) uptake allows noninvasive assessment of tumor hypoxia, and is amenable for repeated studies during fractionated radiotherapy to systematically evaluate changes in tumor oxygenation. Methods and Materials: Seven patients with locally advanced nonsmall cell lung cancers underwent sequential [F-18]FMISO PET imaging while receiving primary radiotherapy. Computed tomograms were used to calculate tumor volumes, define tumor extent for PET image analysis, and assist in PET image registration between serial studies. Fractional hypoxic volume (FHV) was calculated for each study as the percentage of pixels within the analyzed imaged tumor volume with a tumor:blood [F-18]FMISO ratio ≥ 1.4 by 120 min after injection. Serial FHVs were compared for each patient. Results: Pretreatment FHVs ranged from 20-84% (median 58%). Subsequent FHVs varied from 8-79% (median 29%) at midtreatment, and ranged from 3-65% (median 22%) by the end of radiotherapy. One patient had essentially no detectable residual tumor hypoxia by the end of radiation, while two others showed no apparent decrease in serial FHVs. There was no correlation between tumor size and pretreatment FHV. Conclusions: Although there is a general tendency toward improved oxygenation in human tumors during fractionated radiotherapy, these changes are unpredictable and may be insufficient in extent and timing to overcome the negative effects of existing pretreatment hypoxia. Selection of patients for clinical trials addressing radioresistant hypoxic cancers can be appropriately achieved through single pretreatment evaluations of tumor hypoxia

  10. Experimental results and clinical implications of the four R's in fractionated radiotherapy

    International Nuclear Information System (INIS)

    Trott, K.R.; Gesellschaft fuer Strahlen- und Umweltforschung m.b.H. Muenchen, Neuherberg

    1982-01-01

    Experimental and clinical data on the four R' in fractionated radiotherapy are reviewed. The clinical importance of redistribution has not been proven in the experiment yet. On reoxygenation no unequivocal data in human cancer exists and a lot of variability in rodent tumours. Repair and regeneration are the most important of the four R's in fractionated radiotherapy. The presented experimental and clinical evidence suggests a differential response between tumour and late responding normal tissues with regard to these two R's. Tumours appear to have, in general, a smaller capacity for repairing sublethal radiation damage but a higher capacity for repopulation than late responding normal tissues. (orig.)

  11. Prospective randomised multicenter trial on single fraction radiotherapy (8 Gyx1) versus multiple fractions (3 Gyx10) in the treatment of painful bone metastases

    International Nuclear Information System (INIS)

    Kaasa, Stein; Brenne, Elisabeth; Lund, Jo-Asmund; Fayers, Peter; Falkmer, Ursula; Holmberg, Matts; Lagerlund, Magnus; Bruland, Oivind

    2006-01-01

    Background and purpose: To investigate whether single-fraction radiotherapy is equal to multiple fractions in the treatment of painful metastases. Patients and methods: The study planned to recruit 1000 patients with painful bone metastases from four Norwegian and six Swedish hospitals. Patients were randomized to single-fraction (8 Gyx1) or multiple-fraction (3 Gyx10) radiotherapy. The primary endpoint of the study was pain relief, with fatigue and global quality of life as the secondary endpoints. Results: The data monitoring committee recommended closure of the study after 376 patients had been recruited because interim analyses indicated that, as in two other recently published trials, the treatment groups had similar outcomes. Both groups experienced similar pain relief within the first 4 months, and this was maintained throughout the 28-week follow-up. No differences were found for fatigue and global quality of life. Survival was similar in both groups, with median survival of 8-9 months. Conclusions: Single-fraction 8 Gy and multiple-fraction radiotherapy provide similar pain benefit. These results, confirming those of other studies, indicate that single-fraction 8 Gy should be standard management policy for these patients

  12. A randomized study of accelerated fractionation radiotherapy with and without mitomycin C in the treatment of locally advanced head and neck cancer

    DEFF Research Database (Denmark)

    Ezzat, M.; Shouman, T.; Zaza, K.

    2005-01-01

    Objectives: This single-institution study evaluates the feasibility of accelerated fractionation radiotherapy (AF) with and without mitomycin C (MMC) in the treatment of locally advanced head and neck cancer. Patients and Methods: Between May 1998 and October 2001, sixty patients with locally...... advanced stage III and IV of head and neck cancer were randomized into three treatment arms: (1) conventional fractionation radiotherapy (CF) (5 fractions per week); (2) accelerated fractionation radiotherapy (AF) (6 fractions per week); and (3) AF plus Mitomycin C (MMC). Results: The 2-year overall....... Key Words: Head and Neck cancer , Radiotherapy , Altered fractionation , Mitomycin C....

  13. Hyperfractionation as an altered fractionation regimen in primary radiotherapy for squamous cell carcinoma of the larynx

    International Nuclear Information System (INIS)

    Krstevska, V.; Smichkoska, S.

    2006-01-01

    The aim of the study was to investigate the efficacy of hyperfractionation as altered fractionation treatment schedule in comparison with conventional fractionation in primary definitive radiotherapy for laryngeal squamous cell carcinoma. From March 1999 to December 2000, a group of 28 patients with previously untreated squamous cell carcinoma of the larynx were irradiated with conventional fractionation to to total doses of 66 to 70 Gy in 33 to 35 fraction/6.5 to 7 weeks, 2 Gy/fraction/day, 5 days/week. From January 2001 to June 2004, the other 27 patients with the same diagnosis, were treated prospectively with hyperfractionation receiving radiotherapy delivered at 1.2 Gy/fraction, twice daily, 5 days/week to 74.4 to 79.2 Gy/62 to fractions/6.2 to 7 weeks. Complete response rates after two mounts of radiotherapy completion were 78.6% (22 of 28) and 66.7% (18 of 27) in the conventional fractionation and hyperfractionation group, respectively (Fisher exact test; P=0.246). The two year loco-regional control rates were 61 .0%±18.1 (95% CI) in the conventional fractionation group and 45.0%±18.8 (95% CI) in the hyperfractionation group (long-rank test; P=0.075). Overall survival rate at two years was 71.0%±16.8 (95% CI) for the conventional group and 43.0%±18.7 (95% CI) for the hyperfractionation group (long- rank test; P=0.071). The absence of statistically significant differences either in loco-regional control or overall survival observed between the two treatment modalities suggested that hyperfractionation regimen was not more efficacious than conventionally fractionated radiotherapy for previously untreated carcinoma of the larynx.

  14. Radiotherapy Dose Fractionation under Parameter Uncertainty

    International Nuclear Information System (INIS)

    Davison, Matt; Kim, Daero; Keller, Harald

    2011-01-01

    In radiotherapy, radiation is directed to damage a tumor while avoiding surrounding healthy tissue. Tradeoffs ensue because dose cannot be exactly shaped to the tumor. It is particularly important to ensure that sensitive biological structures near the tumor are not damaged more than a certain amount. Biological tissue is known to have a nonlinear response to incident radiation. The linear quadratic dose response model, which requires the specification of two clinically and experimentally observed response coefficients, is commonly used to model this effect. This model yields an optimization problem giving two different types of optimal dose sequences (fractionation schedules). Which fractionation schedule is preferred depends on the response coefficients. These coefficients are uncertainly known and may differ from patient to patient. Because of this not only the expected outcomes but also the uncertainty around these outcomes are important, and it might not be prudent to select the strategy with the best expected outcome.

  15. The radiobiology of prostate cancer including new aspects of fractionated radiotherapy

    International Nuclear Information System (INIS)

    Fowler, Jack F.

    2005-01-01

    Total radiation dose is not a reliable measure of biological effect when dose-per-fraction or dose-rate is changed. Large differences in biological effectiveness (per gray) are seen between the 2 Gy doses of external beam radiotherapy and the large boost doses given at high dose-rate from afterloading sources. The effects are profoundly different in rapidly or slowly proliferating tissues, that is for most tumors versus late complications. These differences work the opposite way round for prostate tumors versus late complications compared with most other types of tumor. Using the Linear-Quadratic formula it is aimed to explain these differences, especially for treatments of prostate cancer. The unusually slow growth rate of prostate cancers is associated with their high sensitivity to increased fraction size, so a large number of small fractions, such as 35 or 40 'daily' doses of 2 Gy, is not an optimum treatment. Theoretical modeling shows a stronger enhancement of tumor effect than of late complications for larger (and fewer) fractions, in prostate tumors uniquely. Biologically Effective Doses and Normalized Total Doses (in 2 Gy fraction equivalents) are given for prostate tumor, late rectal reactions, and - a new development - acute rectal mucosa. Tables showing the change of fraction-size sensitivity (the alpha/beta ratio) with proliferation rates of tissues lead to the association of slow cell doubling times in prostate tumors with small alpha/beta ratios. Clinical evidence to confirm this biological expectation is reviewed. The alpha/beta ratios of prostate tumors appear to be as low as 1.5 Gy (95% confidence interval 1.3-1.8 Gy), in contrast with the value of about 10 Gy for most other types of tumor. The important point is that alpha/beta ratio=1.5 Gy appears to be significantly less than the alpha/beta ratio=3 Gy for late complications in rectal tissues. Such differences are also emerging from recent clinical results. From this important difference stems

  16. P53 function influences the effect of fractionated radiotherapy on glioblastoma tumors

    International Nuclear Information System (INIS)

    Haas-Kogan, Daphne A.; Kogan, Scott S.; Yount, Garret; Hsu, Jennie; Haas, Martin; Deen, Dennis F.; Israel, Mark A.

    1999-01-01

    Purpose: Glioblastoma multiforme brain tumors (GM) are treated with a spectrum of fractionation regimens based on the clinical and anatomical characteristics of the tumor but rarely based on the molecular characteristics of the individual neoplasm. This study tests the hypothesis that the response of cell lines derived from GM to fractionated radiotherapy depends on the function of wild-type p53 (wt p53), a tumor suppressor gene frequently mutated in GM tumors. Methods and Materials: Isogenic derivatives of glioblastoma cells differing only in p53 function were prepared using a retroviral vector expressing a dominant negative mutant of p53 (mt p53). Radiation survival in vitro was quantitated using linear quadratic and repair-saturation mathematical models. Apoptosis was assayed by a terminal deoxynucleotide transferase-labeling technique and chromatin morphology. Results: We have previously reported the generation of isogenic GM cell lines differing only in p53 function. U87-175.4, lacking wt p53 function, had a significantly lower α/β value than U87-LUX.8, expressing functional wt p53, leading us to hypothesize that fractionated irradiation would preferentially spare GM cells harboring mt p53 compared with those expressing functional, wt p53. Survival curves following either 2.0 Gy or 3.5 Gy/fraction demonstrated that lack of functional wt p53 was associated with resistance to fractionated irradiation. Radiation-induced apoptosis could not account for the observed differences in clonogenic survival. Rather, our data suggested that a deficit in the G1-checkpoint contributed to increased resistance to fractionated irradiation of cells expressing mutant p53. Conclusions: The effect of fractionated radiotherapy in GM may depend on the function of the tumor suppressor gene p53. A potential clinical consequence of these findings is that hyperfractionation regimens may provide a therapeutic advantage specifically for tumors expressing wt p53 whereas a radiotherapy

  17. Radical radiotherapy for invasive bladder cancer: What dose and fractionation schedule to choose?

    International Nuclear Information System (INIS)

    Pos, Floris J.; Hart, Guus; Schneider, Christoph; Sminia, Peter

    2006-01-01

    Purpose: To establish the α/β ratio of bladder cancer from different radiotherapy schedules reported in the literature and provide guidelines for the design of new treatment schemes. Methods and Materials: Ten external beam radiotherapy (EBRT) and five brachytherapy schedules were selected. The biologically effective dose (BED) of each schedule was calculated. Logistic modeling was used to describe the relationship between 3-year local control (LC3y) and BED. Results: The estimated α/β ratio was 13 Gy (95% confidence interval [CI], 2.5-69 Gy) for EBRT and 24 Gy (95% CI, 1.3-460 Gy) for EBRT and brachytherapy combined. There is evidence for an overall dose-response relationship. After an increase in total dose of 10 Gy, the odds of LC3y increase by a factor of 1.44 (95% CI, 1.23-1.70) for EBRT and 1.47 (95% CI, 1.25-1.72) for the data sets of EBRT and brachytherapy combined. Conclusion: With the clinical data currently available, a reliable estimation of the α/β ratio for bladder cancer is not feasible. It seems reasonable to use a conventional α/β ratio of 10-15 Gy. Dose escalation could significantly increase local control. There is no evidence to support short overall treatment times or large fraction sizes in radiotherapy for bladder cancer

  18. Effects of fractionated stereotactic radiotherapy for primary hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Choi, Byeong Ock; Jang, Hong Seok; Kang, Young Nam; Choi, Ihl Bhong; Kang, Ki Mun; Chai, Gyu Young; Lee, Sang Wook

    2005-01-01

    Reports on the outcome of curative radiotherapy for the primary hepatocellular carcinoma (HCC) are rarely encountered in the literature. In this study, we report our experience of a clinical trial where fractionated stereotactic radiotherapy (SRT) was used in treating a primary HCC. A retrospective analysis was performed on 20 patients who had been histologically diagnosed as HCC and treated by fractionated SRT. The long diameter of tumor measured by CT was 2 ∼ 6.5 cm (average: 3.8 cm). A single dose of radiation used in fractionated SRT was 5 or 10 Gy; each dose was prescribed based on the planning target volume and normalized to 85 ∼ 99% isocenter dose. Patients were treated 3 ∼ 5 times per week for 2 weeks, with each receiving a total dose of 50 Gy (the median dose: 50 Gy). The follow up period was 3 ∼ 55 months (the median follow up period: 23 months). The response rate was 60% (12 patients), with 4 patients showing complete response (20%), 8 patients showing partial response (40%), and 8 patients showing stable disease (40%). The 1-year and 2-year survival rates were 70.0% and 43.1%, respectively,and the median survival time was 20 months. The 1-year and 2-year disease free survival rates were 65% and 32.5%, respectively, and the median disease-free survival rate was 19 months. Some acute complications of the treatment were noted as follows: dyspepsia in 12 patients (60%), nausea/emesis in 8 patients (40%), and transient liver function impairment in 6 patients (30%). However, there was no treatment related death. The study indicates that fractionated SRT is a relatively safe and effective method for treating primary HCC. Thus, fractionated SRT may be suggested as a local treatment for HCC of small lesion and containing a single lesion, when the patients are inoperable or operation is refused by the patients. We thought that fractionated SRT is a challenging treatment modality for the HCC

  19. Study of inter-fractional variations and adaptive radiotherapy in pancreatic cancer

    International Nuclear Information System (INIS)

    Yang Chengliang; Wang Jianhua; Li Dingjie; Mao Ronghu; Li, X. Allen

    2012-01-01

    Objective: To quantitatively characterize the inter-fractional anatomy variations and advantages of dosimetry for the adaptive radiotherapy in pancreatic cancer. Methods: A total of 226 daily CT images acquired from 10 patients with pancreatic cancer treated with image-guided radiotherapy were analyzed retrospectively. Targets and organs at risk (OARs) were delineated by the atlas-based automatic segmentation and modified by the skilled physician. Various parameters,including the center of mass (COM) distance, the maximal overlap ratio (MOR) and the Dice coefficient (DC), were used to quantify the inter-fractional organ displacement and deformation. The adaptive radiation therapy (ART) was applied to handle the daily GT images. The dose distributions parameters from the ART plan were compared with those from the repositioning plan. Results: The inter-fractional anatomy variations of pancreas head were obvious in the pancreatic cancer irradiation. The mean COM distance, MOR and DC of pancreas head after the bony or soft tissue alignment and registration was (7.8 ± 1.3)mm, (87.2 ± 8.4)% and (77.2 ±7.9)% respectively. Compared with the repositioning plan, the ART plan had better target coverage and OARs sparing. For example, the mean V 100 of PTV was improved from (93.32 ± 2.89) % for repositioning plan to (96.03 ± 1.42)% for ART plan with t =2.79, P =0.008 and the mean V 50.4 for duodenum was reduced from (43.4 ± 12.71)% for the repositioning plan to (15.6 ± 6.25)% for the ART plan with t =3.52, P=0.000. Conclusions: The ART can effectively account for the obvious inter-fractional anatomy variations in pancreatic cancer irradiation and be used to escalate the radiotherapy dose for the pancreatic cancer, which will lead to a promising higher local control rate. (authors)

  20. Table-sized matrix model in fractional learning

    Science.gov (United States)

    Soebagyo, J.; Wahyudin; Mulyaning, E. C.

    2018-05-01

    This article provides an explanation of the fractional learning model i.e. a Table-Sized Matrix model in which fractional representation and its operations are symbolized by the matrix. The Table-Sized Matrix are employed to develop problem solving capabilities as well as the area model. The Table-Sized Matrix model referred to in this article is used to develop an understanding of the fractional concept to elementary school students which can then be generalized into procedural fluency (algorithm) in solving the fractional problem and its operation.

  1. The HYP-RT Hypoxic Tumour Radiotherapy Algorithm and Accelerated Repopulation Dose per Fraction Study

    Directory of Open Access Journals (Sweden)

    W. M. Harriss-Phillips

    2012-01-01

    Full Text Available The HYP-RT model simulates hypoxic tumour growth for head and neck cancer as well as radiotherapy and the effects of accelerated repopulation and reoxygenation. This report outlines algorithm design, parameterisation and the impact of accelerated repopulation on the increase in dose/fraction needed to control the extra cell propagation during accelerated repopulation. Cell kill probabilities are based on Linear Quadratic theory, with oxygenation levels and proliferative capacity influencing cell death. Hypoxia is modelled through oxygen level allocation based on pO2 histograms. Accelerated repopulation is modelled by increasing the stem cell symmetrical division probability, while the process of reoxygenation utilises randomised pO2 increments to the cell population after each treatment fraction. Propagation of 108 tumour cells requires 5–30 minutes. Controlling the extra cell growth induced by accelerated repopulation requires a dose/fraction increase of 0.5–1.0 Gy, in agreement with published reports. The average reoxygenation pO2 increment of 3 mmHg per fraction results in full tumour reoxygenation after shrinkage to approximately 1 mm. HYP-RT is a computationally efficient model simulating tumour growth and radiotherapy, incorporating accelerated repopulation and reoxygenation. It may be used to explore cell kill outcomes during radiotherapy while varying key radiobiological and tumour specific parameters, such as the degree of hypoxia.

  2. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Rune, E-mail: rune333@gmail.com [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Claesson, Magnus [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Stangerup, Sven-Eric [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Roed, Henrik [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); Christensen, Ib Jarle [Finsen Laboratory, Rigshospitalet, Copenhagen (Denmark); Caye-Thomasen, Per [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Juhler, Marianne [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark)

    2012-08-01

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a 'wait-and-scan' group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  3. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    International Nuclear Information System (INIS)

    Rasmussen, Rune; Claesson, Magnus; Stangerup, Sven-Eric; Roed, Henrik; Christensen, Ib Jarle; Cayé-Thomasen, Per; Juhler, Marianne

    2012-01-01

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a “wait-and-scan” group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  4. Single vs. multiple fraction regimens for palliative radiotherapy treatment of multiple myeloma. A prospective randomised study

    International Nuclear Information System (INIS)

    Rudzianskiene, Milda; Inciura, Arturas; Gerbutavicius, Rolandas; Rudzianskas, Viktoras; Dambrauskiene, Ruta; Juozaityte, Elona; Macas, Andrius; Simoliuniene, Renata; Kiavialaitis, Greta Emilia

    2017-01-01

    To compare the impact of a single fraction (8 Gy x 1 fraction) and multifraction (3 Gy x 10 fractions) radiotherapy regimens on pain relief, recalcification and the quality of life (QoL) in patients with bone destructions due to multiple myeloma (MM). In all, 101 patients were included in a randomised prospective clinical trial: 58 patients were included in the control arm (3 Gy x 10 fractions) and 43 patients into the experimental arm (8 Gy x 1 fraction). The response rate was defined according to the International Consensus on Palliative Radiotherapy criteria. Recalcification was evaluated with radiographs. QoL questionnaires were completed before and 4 weeks after treatment. Pain relief was obtained in 81/101 patients (80.2%): complete response in 56 (69%) and partial in 25 patients (30.9%). No significant differences were observed in analgesic response between the groups. Significant factors for pain relief were female gender, age under 65, IgG MM type, presence of recalcification at the irradiated site. Recalcification was found in 32/101 patients (33.7%): complete in 17 (53.2%) and partial in 15 (46.2%). No significant differences were observed in recalcification between the groups. Significant factors for recalcification were Karnofsky index ≥ 60%, haemoglobin level ≤ 80 g/dl, MM stage II and analgesic response at the irradiated site. The QoL after radiotherapy was improved in the control group. The same analgesic and recalcification response was observed using two different radiotherapy regimens. Higher doses should be used to achieve a better QoL. (orig.) [de

  5. Fractionated brain stereotactic radiotherapy: assessment of repositioning precision using a thermoforming mask

    International Nuclear Information System (INIS)

    Barret, A.; Champeaux-Orange, E.; Bouscayrol, H.; Wachter, T.

    2011-01-01

    The authors report a study which aimed at assessing the patient repositioning precision obtained with a support system used during a brain fractionated stereotactic radiotherapy and comprising a thermoforming mask (Elektra head mask). The repositioning is assessed by means of scano-graphies and superimposition with the stereotactic frame. A three-dimensional vector has been computed for each patient. The average displacement corresponds to that published in literature. The high quality of the support system allows a non invasive brain stereotactic radiotherapy to be performed which is also comfortable for the patient. Short communication

  6. Endocrine and visual function after fractionated stereotactic radiotherapy of perioptic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, M.; Semrau, R.; Mueller, R.P. [Universitaetsklinikum Koeln (Germany). Klinik und Poliklinik fuer Strahlentherapie; Treuer, H.; Hoevels, M.; Sturm, V. [Koeln Univ. (Germany). Dept. of Stereotaxy and Functional Neurosurgery

    2013-02-15

    Purpose: To find out whether the use of stereotactic techniques for fractionated radiotherapy reduces toxicity to the endocrine and visual system in patients with benign perioptic tumors. Patients and methods: From 1993 to 2009, 29 patients were treated with fractionated stereotactic radiotherapy. The most frequent tumor types were grade I meningioma (n = 11) and pituitary adenoma (n = 10, 7 nonfunctioning, 3 growth hormone-producing). Patients were immobilized with the GTC frame (Radionics, USA) and the planning target volume (PTV; median 24.7, 4.6-58.6 ml) was irradiated with a total dose of 52.2 Gy (range, 45.0-55.8 Gy) in 1.8-Gy fractions using a linear accelerator (6 MeV photons) equipped with a micro-multileaf collimator. Maximum doses to the optic system and pituitary gland were 53.4 Gy (range, 11.5-57.6 Gy) and 53.6 Gy (range, 12.0-57.9 Gy). Results: Median follow-up was 45 months (range, 10-105 months). Local control was achieved in all but 1 patient (actuarial rate 92% at 5 years and 10 years). In 9 of 29 patients (31%), partial remission was observed (actuarial response rate 40% at 5 years and 10 years). In 4 of 26 patients (15%) with at least partial pituitary function, new hormonal deficits developed (actuarial rate 21% at 5 years and 10 years). This rate was significantly higher in patients treated for a larger PTV ( 25 ml: 0% vs. 42% at 5 years and 10 years, p = 0.028). Visual function improved in 4 of 15 patients (27%) who had prior impairment. None of the patients developed treatment-related optic neuropathy, but 2 patients experienced new disease-related visual deficits. Conclusion: Fractionated stereotactic radiotherapy for benign tumors of the perioptic and sellar region results in satisfactory response and local control rates and does not affect the visual system. The assumption that patients can be spared hypophyseal insufficiency only holds for small tumors. (orig.)

  7. Endocrine and visual function after fractionated stereotactic radiotherapy of perioptic tumors

    International Nuclear Information System (INIS)

    Kocher, M.; Semrau, R.; Mueller, R.P.; Treuer, H.; Hoevels, M.; Sturm, V.

    2013-01-01

    Purpose: To find out whether the use of stereotactic techniques for fractionated radiotherapy reduces toxicity to the endocrine and visual system in patients with benign perioptic tumors. Patients and methods: From 1993 to 2009, 29 patients were treated with fractionated stereotactic radiotherapy. The most frequent tumor types were grade I meningioma (n = 11) and pituitary adenoma (n = 10, 7 nonfunctioning, 3 growth hormone-producing). Patients were immobilized with the GTC frame (Radionics, USA) and the planning target volume (PTV; median 24.7, 4.6-58.6 ml) was irradiated with a total dose of 52.2 Gy (range, 45.0-55.8 Gy) in 1.8-Gy fractions using a linear accelerator (6 MeV photons) equipped with a micro-multileaf collimator. Maximum doses to the optic system and pituitary gland were 53.4 Gy (range, 11.5-57.6 Gy) and 53.6 Gy (range, 12.0-57.9 Gy). Results: Median follow-up was 45 months (range, 10-105 months). Local control was achieved in all but 1 patient (actuarial rate 92% at 5 years and 10 years). In 9 of 29 patients (31%), partial remission was observed (actuarial response rate 40% at 5 years and 10 years). In 4 of 26 patients (15%) with at least partial pituitary function, new hormonal deficits developed (actuarial rate 21% at 5 years and 10 years). This rate was significantly higher in patients treated for a larger PTV ( 25 ml: 0% vs. 42% at 5 years and 10 years, p = 0.028). Visual function improved in 4 of 15 patients (27%) who had prior impairment. None of the patients developed treatment-related optic neuropathy, but 2 patients experienced new disease-related visual deficits. Conclusion: Fractionated stereotactic radiotherapy for benign tumors of the perioptic and sellar region results in satisfactory response and local control rates and does not affect the visual system. The assumption that patients can be spared hypophyseal insufficiency only holds for small tumors. (orig.)

  8. Single-centre experience of stereotactic radiosurgery and fractionated stereotactic radiotherapy for prolactinomas with the linear accelerator.

    Science.gov (United States)

    Wilson, Peter J; Williams, Janet Rosemary; Smee, Robert Ian

    2015-06-01

    Primary management of prolactinomas is usually medical, with surgery a secondary option where necessary. This study is a review of a single centre's experience with focused radiotherapy where benefit was not gained by medical or surgical approaches. Radiotherapy as an alternative and adjuvant treatment for prolactinomas has been performed at our institution with the linear accelerator since 1990. We present a retrospective review of 13 patients managed with stereotactic radiosurgery (SRS) and 5 managed with fractionated stereotactic radiotherapy (FSRT), as well as 5 managed with conventional radiotherapy, at the Prince of Wales Hospital. Patients with a histopathologically diagnosed prolactinoma were eligible. Those patients who had a confirmed pathological diagnosis of prolactinoma following surgical intervention, a prolactin level elevated above 500 μg/L, or a prolactin level persistently elevated above 200 μg/L with exclusion of other causes were represented in this review. At the end of documented follow-up (SRS median 6 years, FSRT median 2 years), no SRS patients showed an increase in tumour volume. After FSRT, 1 patient showed an increase in size, 2 showed a decrease in size and 2 patients showed no change. Prolactin levels trended towards improvement after SRS and FSRT, but no patients achieved the remission level of <20 μg/L. Seven of 13 patients in the SRS group achieved a level of <500 μg/L, whereas no patients reached this target after FSRT. A reduction in prolactin level is frequent after SRS and FSRT for prolactinomas; however, true biochemical remission is uncommon. Tumour volume control in this series was excellent, but this may be related to the natural history of the disease. Morbidity and mortality after stereotactic radiation were very low in this series. © 2014 The Royal Australian and New Zealand College of Radiologists.

  9. Tissue kinetics in mouse tongue mucosa during daily fractionated radiotherapy

    International Nuclear Information System (INIS)

    Doerr, W.; Emmendoerfer, H.; Weber-Frisch, M.

    1996-01-01

    The purpose of the present investigation was to quantify cell flux between the distinct layers of the epithelial lining of the ventral surface of mouse tongue during daily fractionated radiotherapy. In tongue epithelium of untreated mice, the minimum residence time of cells in the germinal layer is 2-3 days. Migration through the functional layers requires an additional 2-3 days before labelled cells are observed in the most superficial layer of nucleated cells. A plateau in LI is observed for several days post-labelling in control epithelium, indicating an equilibrium between loss and proliferation of labelled cells. During fractionated radiotherapy, the minimum time from division to occurrence of labelled cells in the stratum lucidum is less than 2 days, and hence significantly shorter than in control epithelium. In contrast to untreated epithelium, no plateau in the germinal layer LI is seen, indicating that frequently both labelled daughters from dividing labelled cells are being lost from this compartment. In conclusion, the present data support a recently described model of radiation-induced accelerated repopulation in squamous epithelia, which postulates that the majority of damaged cells undergoes abortive divisions resulting in two differentiating daughters. (Author)

  10. A retrospective analysis of survival outcomes for two different radiotherapy fractionation schedules given in the same overall time for limited stage small cell lung cancer

    International Nuclear Information System (INIS)

    Bettington, Catherine S.; Bryant, Guy; Hickey, Brigid; Tripcony, Lee; Pratt, Gary; Fay, Michael

    2013-01-01

    To compare survival outcomes for two fractionation schedules of thoracic radiotherapy, both given over 3 weeks, in patients with limited stage small cell lung cancer (LS-SCLC). At Radiation Oncology Mater Centre (ROMC) and the Royal Brisbane and Women's Hospital (RBWH), patients with LS-SCLC treated with curative intent are given radiotherapy (with concurrent chemotherapy) to a dose of either 40Gy in 15 fractions ('the 40Gy/15⧣group') or 45Gy in 30 fractions ('the 45Gy/30⧣group'). The choice largely depends on institutional preference. Both these schedules are given over 3 weeks, using daily and twice-daily fractionation respectively. The records of all such patients treated from January 2000 to July 2009 were retrospectively reviewed and survival outcomes between the two groups compared. Of 118 eligible patients, there were 38 patients in the 40Gy/15⧣ group and 41 patients in the 45Gy/30⧣ group. The median relapse-free survival time was 12 months in both groups. Median overall survival was 21 months (95% CI 2–37 months) in the 40Gy/15⧣ group and 26 months (95% CI 1–48 months) in the 45Gy/30⧣ group. The 5-year overall survival rates were 20% and 25%, respectively (P=0.24). On multivariate analysis, factors influencing overall survival were: whether prophylactic cranial irradiation (PCI) was given (P=0.01) and whether salvage chemotherapy was given at the time of relapse (P=0.057). Given the small sample size, the potential for selection bias and the retrospective nature of our study it is not possible to draw firm conclusions regarding the efficacy of hypofractionated thoracic radiotherapy compared with hyperfractionated accelerated thoracic radiotherapy however hypofractionated radiotherapy may result in equivalent relapse-free survival.

  11. Neurosymptomatic carvenous sinus meningioma: a 15-years experience with fractionated stereotactic radiotherapy and radiosurgery

    International Nuclear Information System (INIS)

    Correa, Sebastião Francisco Miranda; Marta, Gustavo Nader; Teixeira, Manoel Jacobsen

    2014-01-01

    The tumor removal of Cavernous Sinus Meningiomas usually results in severe neurological deficits. Stereotactic radiosurgery (SRS) and fractionated Stereotactic radiotherapy (SRT) are advanced modalities of radiotherapy for treatment of patients with inoperable and symptomatic CSMs. The authors evaluated the long term symptomatology, the image findings, and the toxicity of patients with CSMs treated with SRS or SRT. From 1994 to 2009, 89 patients with symptomatic CSMs were treated with SRS or SRT. The indication was based on tumour volume and or proximity to the optic chiasm. The median single dose of SRS was 14 Gy, while the SRT total dose, ranged from 50.4 to 54 Gy fractionated in 1.8-2 Gy/dose. The median follow-up period lasted 73 months. The clinical and radiological improvement was the same despite the method of radiotherapy; 41.6% (SRS) and 48.3% (SRT) of patients treated. The disease-free survivals were 98.8%, 92.3% and 92.3%, in 5, 10, and 15 years, respectively. There was no statistical difference in relation to the symptoms and image findings between both methods. According to the Common Toxicity Criteria, 7% of the patients presented transient optic neuropathy during 3 months (grade 2) and recovered with dexamethasone, 2 patients had trigeminal neuropathy (grade 2) and improved rapidly, and one patient presented total occlusion of the internal carotid artery without neurological deficit (grade 2). Temporary lethargy and headache (grade 1) were the most frequent immediate complications. No severe complications occurred. Stereotactic Radiosurgery and fractionated Stereotactic Radiotherapy were equally safe and effective in the management of symptomatic CSMs

  12. Multiple daily fractionation in radiotherapy: biological rationale and preliminary clinical experiences

    Energy Technology Data Exchange (ETDEWEB)

    Arcangeli, G [Instituto Medico Scientifico, Rome (Italy). Dept. of Oncology; Mauro, F; Morelli, D; Nervi, C

    1979-09-01

    The biological bases of radiation dose fractionation are reviewed and discussed with special emphasis on reassortment. Experimental data on animal model systems are presented to clarify that reassortment has to be added to sublethal damage repair and reoxygenation in the rationale for an optimized radiotherapy course according to tumor cell kinetics. Clinical results on several human tumors treated with twice or thrice daily fractions are described. These results show that some clinically radioresistant tumors (especially if not characterized by a relatively long clinical doubling line) can be satisfactorily dealt with using multiple daily fractionation. Clinical observations indicate that a relatively high cumulative daily dose (200 + 150 + 150 rad) can be safely administered.

  13. Palliative radiotherapy for lung cancer: two versus five fractions

    Energy Technology Data Exchange (ETDEWEB)

    Rees, G.J.G.; Devrell, C.E.; Barley, V.L.; Newman, H.F.V. [Bristol Oncology Centre (United Kingdom)

    1997-09-01

    The aim of this prospective randomized trial was to compare the symptomatic effects of two different regimens of palliative radiotherapy for lung cancer. Two hundred and sixteen patients needing palliation were randomized to receive either a 17 Gy mid-point dose in two fractions 1 week apart or 22.5 gy in five daily fractions. Both toxicity and efficacy were evaluated by postal questionnaires. This small study was intended to identify any clinically important differences in toxicity of efficacy between the two regimens. We detected no such difference, although there was a tendency for iatrogentic dysphagia and improvement in chest pain and cough to be more common with the two fraction regimen. The only symptom that was improved in over 50% for 8 or more was haemoptysis. Haemoptysis and chest pain appeared to be the best indications for treatment. The relief of other symptoms was disappointing in both degree and duration. (author).

  14. Acute tumor vascular effects following fractionated radiotherapy in human lung cancer: In vivo whole tumor assessment using volumetric perfusion computed tomography

    International Nuclear Information System (INIS)

    Ng, Q.-S.; Goh, Vicky; Milner, Jessica; Padhani, Anwar R.; Saunders, Michele I.; Hoskin, Peter J.

    2007-01-01

    Purpose: To quantitatively assess the in vivo acute vascular effects of fractionated radiotherapy for human non-small-cell lung cancer using volumetric perfusion computed tomography (CT). Methods and Materials: Sixteen patients with advanced non-small-cell lung cancer, undergoing palliative radiotherapy delivering 27 Gy in 6 fractions over 3 weeks, were scanned before treatment, and after the second (9 Gy), fourth (18 Gy), and sixth (27 Gy) radiation fraction. Using 16-detector CT, multiple sequential volumetric acquisitions were acquired after intravenous contrast agent injection. Measurements of vascular blood volume and permeability for the whole tumor volume were obtained. Vascular changes at the tumor periphery and center were also measured. Results: At baseline, lung tumor vascularity was spatially heterogeneous with the tumor rim showing a higher vascular blood volume and permeability than the center. After the second, fourth, and sixth fractions of radiotherapy, vascular blood volume increased by 31.6% (paired t test, p = 0.10), 49.3% (p = 0.034), and 44.6% (p = 0.0012) respectively at the tumor rim, and 16.4% (p = 0.29), 19.9% (p = 0.029), and 4.0% (p = 0.0050) respectively at the center of the tumor. After the second, fourth, and sixth fractions of radiotherapy, vessel permeability increased by 18.4% (p = 0.022), 44.8% (p = 0.0048), and 20.5% (p = 0.25) at the tumor rim. The increase in permeability at the tumor center was not significant after radiotherapy. Conclusion: Fractionated radiotherapy increases tumor vascular blood volume and permeability in human non-small-cell lung cancer. We have established the spatial distribution of vascular changes after radiotherapy; greater vascular changes were demonstrated at the tumor rim compared with the center

  15. Radiotherapy and oral cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sealy, R [Cape Town Univ. (South Africa). Dept. of Radiotherapy

    1982-08-01

    A general review article for the non-radiotherapist. The historical, physical and biological background is briefly reviewed. Mention is made of the effects of fraction size, hyperbaric oxygen, neutron beams and radiation sensitizers. The use of chemotherapy and radiotherapy is discussed, as well as the selection of patients for radiotherapy and the treatment of neck nodes. The author suggests a therapeutic approach to the various disease sites and finally reviews some of the literature on radiation caries and jaw necrosis.

  16. The hypo-fractionated radiotherapy in the treatment of the prostate cancer: Radiate less to treat more

    International Nuclear Information System (INIS)

    Boissier, R.; Gross, E.

    2012-01-01

    The principle of the hypo-fractionation in radiotherapy is to deliver a higher dose by session and to reduce the duration of treatment. In the particular case of the cancer of prostate, a hypo-fractionated protocol allows to deliver an equivalent radiobiological dose identical even higher than a standard plan of irradiation. The hypo-fractionation is presented as a solution to improve the access to the care (fewer processing times by patient, more patients treated by machine) while increasing the quality of the care: better carcinological control, less radiotoxicity. The objective of this article is to make a clarification on the hypo-fractionated radiotherapy in first intention in the treatment of the localized prostate cancer. We count three studies on large cohorts, comparing standard plans to 1.8 2 Gy/session and hypo-fractionated plans (2.5 3 Gy/session). The inferior carcinological results of the two first comparative studies with regard to the study of phase I/II of the Cleveland clinic were owed to a sub-dosage of hypo-fractionated plans. The administered equivalent biological doses were lower than the at present recommended total doses and lower than the theoretical doses, calculated on the bases of an erroneous evaluation of the radio-sensibility of the prostate cancer. In the comparative study of Arcangeli, the rate of survival without biological recurrence in 4 years (82%) was significantly to the advantage of the hypo-fractionated group, while reducing the duration of treatment of 3 weeks. Four comparative studies reported acute/late toxicity, gastrointestinal (GI)/genito-urinary acceptable (GU) even lower with a hypo-fractionated plan. The hypo-fractionation is potentially the future of the radiotherapy in the treatment of the localized prostate cancer thanks to the technological innovation, but for all that does not constitute at present a standard. (authors)

  17. Fractionated Stereotactic Radiotherapy in the Treatment of Vestibular Schwannoma (Acoustic Neuroma): Predicting the Risk of Hydrocephalus

    International Nuclear Information System (INIS)

    Powell, Ceri; Micallef, Caroline; Gonsalves, Adam; Wharram, Bev; Ashley, Sue; Brada, Michael

    2011-01-01

    Purpose: To determine the incidence and predictive factors for the development of hydrocephalus in patients with acoustic neuromas (AN) treated with fractionated stereotactic radiotherapy. Patients and Methods: Seventy-two patients with AN were treated with fractionated stereotactic radiotherapy between 1998 and 2007 (45-50 Gy in 25-30 fractions over 5 to 6 weeks). The pretreatment MRI scan was assessed for tumor characteristics and anatomic distortion independently of subsequent outcome and correlated with the risk of hydrocephalus. Results: At a median follow-up of 49 months (range, 1-120 months), 5-year event-free survival was 95%. Eight patients (11%) developed hydrocephalus within 19 months of radiotherapy, which was successfully treated. On univariate analysis, pretreatment factors predictive of hydrocephalus were maximum diameter (p = 0.005), proximity to midline (p = 0.009), displacement of the fourth ventricle (p = 0.02), partial effacement of the fourth ventricle (p < 0.001), contact with the medulla (p = 0.005), and more brainstem structures (p = 0.004). On multivariate analysis, after adjusting for fourth ventricular effacement, no other variables remained independently associated with hydrocephalus formation. Conclusions: Fractionated stereotactic radiotherapy results in excellent tumor control of AN, albeit with a risk of developing hydrocephalus. Patients at high risk, identified as those with larger tumors with partial effacement of the fourth ventricle before treatment, should be monitored more closely during follow-up. It would also be preferable to offer treatment to patients with progressive AN while the risk of hydrocephalus is low, before the development of marked distortion of fourth ventricle before tumor diameter significantly exceeds 2 cm.

  18. Radiobiology of hypofractionated stereotactic radiotherapy: what are the optimal fractionation schedules?

    International Nuclear Information System (INIS)

    Shibamoto, Yuta; Miyakawa, Akifumi; Otsuka, Shinya; Iwata, Hiromitsu

    2016-01-01

    In hypofractionated stereotactic radiotherapy (SRT), high doses per fraction are usually used and the dose delivery pattern is different from that of conventional radiation. The daily dose is usually given intermittently over a longer time compared with conventional radiotherapy. During prolonged radiation delivery, sublethal damage repair takes place, leading to the decreased effect of radiation. In in vivo tumors, however, this decrease in effect may be counterbalanced by rapid reoxygenation. Another issue related to hypofractionated SRT is the mathematical model for dose evaluation and conversion. The linear–quadratic (LQ) model and biologically effective dose (BED) have been suggested to be incorrect when used for hypofractionation. The LQ model overestimates the effect of high fractional doses of radiation. BED is particularly incorrect when used for tumor responses in vivo, since it does not take reoxygenation into account. Correction of the errors, estimated at 5–20%, associated with the use of BED is necessary when it is used for SRT. High fractional doses have been reported to exhibit effects against tumor vasculature and enhance host immunity, leading to increased antitumor effects. This may be an interesting topic that should be further investigated. Radioresistance of hypoxic tumor cells is more problematic in hypofractionated SRT, so trials of hypoxia-targeted agents are encouraged in the future. In this review, the radiobiological characteristics of hypofractionated SRT are summarized, and based on the considerations, we would like to recommend 60 Gy in eight fractions delivered three times a week for lung tumors larger than 2 cm in diameter

  19. Accelerated fractionation radiotherapy for advanced haed and neck cancer

    International Nuclear Information System (INIS)

    Lamb, D.S.; Spry, N.A.; Gray, A.J.; Johnson, A.D.; Alexander, S.R.; Dally, M.J.

    1990-01-01

    Between 1981 and 1986, 89 patients with advanced head and neck squamous cancer were treated with a continuous accelerated fractionation radiotherapy (AFRT) regimen. Three fractions of 1.80 Gy, 4 h apart, were given on three treatment days per week, and the tumour dose was taken to 59.40 Gy in 33 fractions in 24-25 days. Acute mucosal reactions were generally quite severe, but a split was avoided by providing the patient with intensive support, often as an in-patient, until the reactions settled. Late radiation effects have been comparable to those obtained with conventional fractionation. The probability of local-regional control was 47% at 3 years for 69 previously untreated patients, whereas it was only 12% at one year for 20 patients treated for recurrence after radical surgery. Fifty-eight previously untreated patients with tumours arising in the upper aero-digestive tract were analysed in greated detail. The probability of local-regional control at 3 years was 78% for 17 Stage III patients and 15% for 31 Stage IV patients. This schedule of continuous AFRT is feasible and merits further investigation. (author). 31 refs.; 4 figs.; 6 tabs

  20. Fractionated stereotaxic radiotherapy in the treatment of the retinoblastoma: preliminary results; Radiotherapie stereotaxique fractionnee dans le traitement du retinoblastome: resultats preliminaires

    Energy Technology Data Exchange (ETDEWEB)

    Pica, A. [Centre Hospitalier Universitaire Vaudois (CHUV), Service de Radiotherapie, Lausanne (Switzerland); Moeckli, R.; Do, H. [Institut de Radiophysique Appliquee, Lausanne (Switzerland); Balmer, A.; Munier, F. [Hopital ophtalmique Jules-Gonin, Lausanne (Switzerland); Chollet Rivier, M. [Centre Hospitalier Universitaire Vaudois (CHUV), Service d' Anesthesie, Lausanne (Switzerland)

    2006-11-15

    The objective of this study is to evaluate the impact in term of morbidity at short and long term and the response to the fractionated stereotaxic radiotherapy with a micro multi slides collimator in the treatment of the retinoblastoma. (N.C.)

  1. What next in fractionated radiotherapy

    International Nuclear Information System (INIS)

    Fowler, J.F.

    1984-01-01

    Trends in models for predicting the total dose required to produce tolerable normal-tissue injury can be seen by the progression from the ''cube root law'', through Strandqvist's slope of 0.22, to NSD, TDF and CRE which have separate time and fraction number exponents, to even better approximations now available. The dose-response formulae that can be used to define the effect of fraction size (and number) include (1) the linear quadratic (LQ) model (2) the two-component (TC) multi-target model and (3) repair-misrepair models. The LQ model offers considerable convenience, requires only two parameters to be determined, and emphasizes the difference between late and early normal-tissue dependence on dose per fraction first shown by exponents greater than the NSD slope of 0.24. Exponents of overall time, e.g. Tsup(0.11), yield the wrong shape of time curve, suggesting that most proliferating occurs early, although it really occurs after a delay depending on the turnover time of the tissue. Improved clinical results are being sought by hyperfractionation, accelerated fractionation, or continuous low dose rate irradiation as in interstitial implants. (U.K.)

  2. Single vs. multiple fraction regimens for palliative radiotherapy treatment of multiple myeloma. A prospective randomised study

    Energy Technology Data Exchange (ETDEWEB)

    Rudzianskiene, Milda; Inciura, Arturas; Gerbutavicius, Rolandas; Rudzianskas, Viktoras; Dambrauskiene, Ruta; Juozaityte, Elona [Lithuanian University of Health Sciences, Oncology Institute, Kaunas (Lithuania); Macas, Andrius [Lithuanian University of Health Sciences, Anaesthesiology Department, Kaunas (Lithuania); Simoliuniene, Renata [Lithuanian University of Health Sciences, Department of Physics, Mathematics and Biophysics, Kaunas (Lithuania); Kiavialaitis, Greta Emilia [University Hospital Zurich, Intitute of Anesthesiology, Zurich (Switzerland)

    2017-09-15

    To compare the impact of a single fraction (8 Gy x 1 fraction) and multifraction (3 Gy x 10 fractions) radiotherapy regimens on pain relief, recalcification and the quality of life (QoL) in patients with bone destructions due to multiple myeloma (MM). In all, 101 patients were included in a randomised prospective clinical trial: 58 patients were included in the control arm (3 Gy x 10 fractions) and 43 patients into the experimental arm (8 Gy x 1 fraction). The response rate was defined according to the International Consensus on Palliative Radiotherapy criteria. Recalcification was evaluated with radiographs. QoL questionnaires were completed before and 4 weeks after treatment. Pain relief was obtained in 81/101 patients (80.2%): complete response in 56 (69%) and partial in 25 patients (30.9%). No significant differences were observed in analgesic response between the groups. Significant factors for pain relief were female gender, age under 65, IgG MM type, presence of recalcification at the irradiated site. Recalcification was found in 32/101 patients (33.7%): complete in 17 (53.2%) and partial in 15 (46.2%). No significant differences were observed in recalcification between the groups. Significant factors for recalcification were Karnofsky index ≥ 60%, haemoglobin level ≤ 80 g/dl, MM stage II and analgesic response at the irradiated site. The QoL after radiotherapy was improved in the control group. The same analgesic and recalcification response was observed using two different radiotherapy regimens. Higher doses should be used to achieve a better QoL. (orig.) [German] Vergleich der einzeitigen vs. fraktionierten palliativen Radiotherapie in Bezug auf Schmerzlinderung, Knochenrekalzifizierung und Lebensqualitaet (QoL) bei Patienten mit multiplem Myelom (MM). In die randomisierte, prospektive Studie wurden 101 Patienten eingeschlossen: Die Kontrollgruppe (n = 58) erhielt eine fraktionierte (3 Gy x 10 Fraktionen) und die Experimentgruppe (n = 43) eine

  3. Quantifying intra- and inter-fractional motion in breast radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Scott, E-mail: scott.jones@health.qld.gov.au [Division of Cancer Services, Radiation Oncology Mater Centre, Princess Alexandra Hospital, Brisbane (Australia); Fitzgerald, Rhys [Division of Cancer Services, Princess Alexandra Hospital, Brisbane (Australia); Owen, Rebecca; Ramsay, Jonathan [Division of Cancer Services, Radiation Oncology Mater Centre, Princess Alexandra Hospital, Brisbane (Australia)

    2015-03-15

    The magnitude of intra- and inter-fractional variation in the set up of breast cancer patients treated with tangential megavoltage photon beams was investigated using an electronic portal imaging device (EPID). Daily cine-EPID images were captured during delivery of the tangential fields for ten breast cancer patients treated in the supine position. Measurements collected from each image included the central lung distance (CLD), central flash distance (CFD), superior axial measurement (SAM) and the inferior axial measurement (IAM). The variation of motion within a fraction (intra-fraction) and the variation between fractions (inter-fraction) was analysed to quantify set up variation and motion due to respiration. Altogether 3775 EPID images were collected from 10 patients. The effect of respiratory motion during treatment was <0.1 cm standard deviation (SD) in the anterior–posterior (AP) direction. The inter-fraction movement caused by variations in daily set up was larger at 0.28 cm SD in the AP direction. Superior–inferior (SI) variation was more difficult to summarise and proved unreliable as the measurements were taken to an ambiguous point on the images. It was difficult to discern true SI movement from that implicated by AP movement. There is minimal intra-fractional chest wall motion due to respiration during treatment. Inter-fractional variation was larger, however, on average it remained within departmental tolerance (0.5 cm) for set up variations. This review of our current breast technique provides confidence in the feasibility of utilising advanced treatment techniques (field-in-field, intensity modulated radiotherapy or volumetric modulated arc therapy) following a review of the current imaging protocol.

  4. Use of normalized total dose to represent the biological effect of fractionated radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Flickinger, J C; Kalend, A [Pittsburgh University School of Medicine (USA). Department of Radiation Oncology Pittsburg Cancer Institute (USA)

    1990-03-01

    There are currently a number of radiobiological models to account for the effects of dose fractionation and time. Normalized total dose (NTD) is not another new model but is a previously reported, clinically useful form in which to represent the biological effect, determined by any specific radiobiological dose-fractionation model, of a course of radiation using a single set of standardized, easily understood terminology. The generalized form of NTD reviewed in this paper describes the effect of a course of radiotherapy administered with nonstandard fractionation as the total dose of radiation in Gy that could be administered with a given reference fractionation such as 2 Gy per fraction, 5 fractions per week that would produce an equivalent biological effect (probability of complications or tumor control) as predicted by a given dose-fractionation formula. The use of normalized total dose with several different exponential and linear-quadratic dose-fraction formulas is presented. (author). 51 refs.; 1 fig.; 1 tab.

  5. Use of normalized total dose to represent the biological effect of fractionated radiotherapy

    International Nuclear Information System (INIS)

    Flickinger, J.C.; Kalend, A.

    1990-01-01

    There are currently a number of radiobiological models to account for the effects of dose fractionation and time. Normalized total dose (NTD) is not another new model but is a previously reported, clinically useful form in which to represent the biological effect, determined by any specific radiobiological dose-fractionation model, of a course of radiation using a single set of standardized, easily understood terminology. The generalized form of NTD reviewed in this paper describes the effect of a course of radiotherapy administered with nonstandard fractionation as the total dose of radiation in Gy that could be administered with a given reference fractionation such as 2 Gy per fraction, 5 fractions per week that would produce an equivalent biological effect (probability of complications or tumor control) as predicted by a given dose-fractionation formula. The use of normalized total dose with several different exponential and linear-quadratic dose-fraction formulas is presented. (author). 51 refs.; 1 fig.; 1 tab

  6. Conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas

    International Nuclear Information System (INIS)

    Fuss, Martin; Debus, Juergen; Lohr, Frank; Huber, Peter; Rhein, Bernhard; Engenhart-Cabillic, Rita; Wannenmacher, Michael

    2000-01-01

    Purpose: Analysis of local tumor control and functional outcome following conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas. Patients and Methods: From 11/1989 to 9/1999 51 patients with acoustic neuromas have been treated by FSRT. Mean total dose was 57.6 ± 2.5 Gy. Forty-two patients have been followed for at least 12 months and were subject of an outcome analysis. Mean follow-up was 42 months. We analyzed local control, hearing preservation, and facial and trigeminal nerve functional preservation. We evaluated influences of tumor size, age, and association with neurofibromatosis Type 2 (NF2) on outcome and treatment related toxicity. Results: Actuarial 2- and 5-year tumor control rates were 100% and 97.7%, respectively. Actuarial useful hearing preservation rate was 85% at 2 and 5 years. New hearing loss was diagnosed in 4 NF2 patients. Pretreatment normal facial nerve function was preserved in all cases. Two cases of new or impaired trigeminal nerve dysesthesia required medication. No other cranial nerve deficit was observed. In Patients without NF2 tumor size or age had no influence on tumor control and cranial nerve toxicity. Diagnosis of NF2 was associated with higher risk of hearing impairment (p 0.0002), the hearing preservation rate in this subgroup was 60%. Conclusion: FSRT has been shown to be an effective means of local tumor control. Excellent hearing preservation rates and 5th and 7th nerve functional preservation rates were achieved. The results support the conclusion that FSRT can be recommended to patients with acoustic neuromas where special attention has to be taken to preserve useful hearing and normal cranial nerve function. For NF2 patients, FSRT may be the treatment of choice with superior functional outcome compared to treatment alternatives.

  7. Influence of fractionation and time on local control of T1 and T2 glottic carcinoma

    International Nuclear Information System (INIS)

    Le, Quynh-Thu; Krieg, Richard M.; Quivey, Jeanne M.; Fu, Karen K.; Meyler, Thomas S.; Stuart, Alex A.; Phillips, Theodore L.

    1996-01-01

    Purpose: To evaluate the influence of fraction size and overall time on local control of T1 and T2 glottic carcinoma Methods and Materials: Between 1956 and 1995, 318 consecutive patients with early glottic carcinoma (250 T1, 68 T2) were treated with definitive megavoltage radiotherapy at UCSF. Treatment was delivered using conventional fractionation at one fraction/day, 5 days/week. Minimum tumor dose ranged from 50 to 81Gy (median: 61Gy). The fraction size was 200cGy. Conclusions: Risk of tumor recurrence increased with higher T-stage, smaller fraction size, and longer overall time. Our results suggest that for optimal local control, radiotherapy for early glottic carcinoma should be completed as soon as possible, preferably within 6 weeks, using a fraction size ≥ 225cGy. Our current policy is to treat T1 and T2 vocal cord carcinomas with 225cGy/fraction/day, 5 days/week to a total dose of 63-65Gy

  8. Management of acoustic neuromas with fractionated stereotactic radiotherapy (FSRT): Long-term results in 106 patients treated in a single institution

    International Nuclear Information System (INIS)

    Combs, Stephanie E.; Volk, Sigrid; Schulz-Ertner, Daniela; Huber, Peter E.; Thilmann, Christoph; Debus, Juergen

    2005-01-01

    Purpose: To assess the long-term outcome and toxicity of fractionated stereotactic radiotherapy for acoustic neuromas in 106 patients treated in a single institution. Patients and Methods: Between October 1989 and January 2004, fractionated stereotactic radiotherapy (FSRT) was performed in 106 patients with acoustic neuroma (AN). The median total dose applied was 57.6 Gy in median single fractions of 1.8 Gy in five fractions per week. The median irradiated tumor volume was 3.9 mL (range, 2.7-30.7 mL). The median follow-up time was 48.5 months (range, 3-172 months). Results: Fractionated stereotactic radiotherapy was well tolerated in all patients. Actuarial local tumor control rates at 3- and 5- years after FSRT were 94.3% and 93%, respectively. Actuarial useful hearing preservation was 94% at 5 years. The presence of neurofibromatosis (NF-2) significantly adversely influenced hearing preservation in patients that presented with useful hearing at the initiation of RT (p = 0.00062). Actuarial hearing preservation without the diagnosis of NF-2 was 98%. In cases with NF-2, the hearing preservation rate was 64%. Cranial nerve toxicity other than hearing impairment was rare. The rate of radiation induced toxicity to the trigeminal and facial nerve was 3.4% and 2.3%, respectively. Conclusion: Fractionated stereotactic radiotherapy is safe and efficacious for the treatment of AN, with mild toxicity with regard to hearing loss and cranial nerve function. FSRT might be considered as an equieffective treatment modality compared to neurosurgery and therefore represents an interesting alternative therapy for patients with AN

  9. Density fractions versus size separates: does physical fractionation isolate functional soil compartments?

    Directory of Open Access Journals (Sweden)

    C. Moni

    2012-12-01

    Full Text Available Physical fractionation is a widely used methodology to study soil organic matter (SOM dynamics, but concerns have been raised that the available fractionation methods do not well describe functional SOM pools. In this study we explore whether physical fractionation techniques isolate soil compartments in a meaningful and functionally relevant way for the investigation of litter-derived nitrogen dynamics at the decadal timescale. We do so by performing aggregate density fractionation (ADF and particle size-density fractionation (PSDF on mineral soil samples from two European beech forests a decade after application of 15N labelled litter.

    Both density and size-based fractionation methods suggested that litter-derived nitrogen became increasingly associated with the mineral phase as decomposition progressed, within aggregates and onto mineral surfaces. However, scientists investigating specific aspects of litter-derived nitrogen dynamics are pointed towards ADF when adsorption and aggregation processes are of interest, whereas PSDF is the superior tool to research the fate of particulate organic matter (POM.

    Some methodological caveats were observed mainly for the PSDF procedure, the most important one being that fine fractions isolated after sonication can not be linked to any defined decomposition pathway or protective mechanism. This also implies that historical assumptions about the "adsorbed" state of carbon associated with fine fractions need to be re-evaluated. Finally, this work demonstrates that establishing a comprehensive picture of whole soil OM dynamics requires a combination of both methodologies and we offer a suggestion for an efficient combination of the density and size-based approaches.

  10. Better compliance with hypofractionation vs. conventional fractionation in adjuvant breast cancer radiotherapy. Results of a single, institutional, retrospective study

    Energy Technology Data Exchange (ETDEWEB)

    Rudat, Volker; Nour, Alaa; Hammoud, Mohamed; Abou Ghaida, Salam [Saad Specialist Hospital, Department of Radiation Oncology, Al Khobar (Saudi Arabia)

    2017-05-15

    The aim of the study was to identify factors significantly associated with the occurrence of unintended treatment interruptions in adjuvant breast cancer radiotherapy. Patients treated with postoperative radiotherapy of the breast or chest wall between March 2014 and August 2016 were evaluated. The radiotherapy regimens and techniques applied were either conventional fractionation (CF; 28 daily fractions of 1.8 Gy or 25 fractions of 2.0 Gy) or hypofractionation (HF; 15 daily fractions of 2.67 Gy) with inverse planned intensity-modulated radiotherapy (IMRT) or three-dimensional planned conformal radiotherapy (3DCRT). Logistic regression analysis was used to identify factors associated with noncompliance. Noncompliance was defined as the missing of at least one scheduled radiotherapy fraction. In all, 19 of 140 (13.6%) patients treated with HF and 39 of 146 (26.7%) treated with CF experienced treatment interruptions. Of 23 factors tested, the fractionation regimen emerged as the only independent significant prognostic factor for noncompliance on multivariate analysis (CF; p = 0.007; odds ratio, 2.3; 95% confidence interval, 1.3-4.2). No statistically significant differences concerning the reasons for treatment interruptions could be detected between patients treated with CF or HF. HF is significantly associated with a better patient compliance with the prescribed radiotherapy schedule compared with CF. The data suggest that this finding is basically related to the shorter overall treatment time of HF. (orig.) [German] Ziel der Untersuchung war es, Faktoren zu identifizieren, die mit ungeplanten Behandlungsunterbrechungen bei der adjuvanten Strahlentherapie des Mammakarzinoms assoziiert sind. Es wurden Patienten untersucht, die eine adjuvante Strahlentherapie der Mamma oder Brustwand zwischen Maerz 2014 und August 2016 erhielten. Zur Anwendung kamen als Fraktionierungsprotokoll und strahlentherapeutische Technik eine konventionell fraktionierte (CF; 28 Fraktionen mit

  11. Proliferation studies for different radiotherapy fractionation regimes

    International Nuclear Information System (INIS)

    Jones, L.

    1996-01-01

    Full text: This study was undertaken to investigate extended treatment schedules and compare the differences between schedules for highly proliferative tumours. Treatment schedules can be extended for various reasons e.g. public holidays, early side effects. For highly proliferative tumours this can dramatically reduce the effective dose delivered to the tumour. To deduce the most effective schedule fractionation regimes are compared to a common schedule so that the effects can be understood. Thus an equation to allow this to be done for the proliferative case has been derived. (i) The linear quadratic model with proliferation has been used to investigate the effect on biological effective dose (BED) when treatment schedules are extended. (ii) An equation was derived for comparison with a standard effective dose (SED) of 2Gy/fraction given daily 5 days per week, this is a common schedule in most radiotherapy centres. The SED equation derived for the proliferative case is where n 1 and n 2 are the number of fractions for the initial and equivalent schedules respectively, d 1 is the dose delivered per fraction for the initial schedules. T 1 is the time taken for the initial schedule (in days) and T p is the proliferation half life for the tumour involved. SEDs were calculated for the CHART regime of 36 fractions at 1.5 Gy in 12 days (Saunders et al. 1988, cited in Fowler J F, Brit. J. Radiol. 62: 679-694, 1989) and various other schedules. Late effects of these schedules and their standard equivalents were compared. The dose required to achieve the same BED when a treatment schedule is extended has been found to be quite large in some circumstances. For breast tumours a loss of 2Gy 10 BED to tumour occurs after ten days extension of treatment time (T p =12 days,T k =12 days). For head and neck tumours a loss of 2Gy 10 BED occurs after only three and a half days (T p =3 days). From these results it seems that an accelerated fractionation schedule would be advantageous

  12. Hypofractionated Adjuvant Whole Breast Radiotherapy: Progress and Prospects

    International Nuclear Information System (INIS)

    Yarnold, John; Haviland, Joanne

    2010-01-01

    Published results of randomised trials involving >7000 women confirm the safety and efficacy of hypofractionated schedules of adjuvant radiotherapy for women with early breast cancer using fraction sizes between 2 and 3 Gy assuming appropriate downward adjustments to total dose. Unnecessary concerns relating to heart tolerance, suboptimal dose distribution and duration of follow up need not discourage the routine adoption of 15- or 16-fraction schedules in women treated by breast conservation surgery for early breast cancer. Regardless of fractionation regimen, dose escalation to the index quadrant in high risk subgroups will result in a greater relative increase in late adverse effects than tumour control, a therapeutic disadvantage that can only be overcome by exploiting a marked dose-volume effect. A 15-fraction schedule of whole breast radiotherapy is unlikely to represent the lower limits of hypofractionation, and the preliminary results of a 5-fraction regimen are encouraging

  13. Single Fraction Versus Fractionated Linac-Based Stereotactic Radiotherapy for Vestibular Schwannoma: A Single-Institution Experience

    Energy Technology Data Exchange (ETDEWEB)

    Collen, Christine, E-mail: ccollen@uzbrussel.be [Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Ampe, Ben [Department of Neurosurgery, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Gevaert, Thierry [Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Moens, Maarten [Department of Neurosurgery, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Linthout, Nadine; De Ridder, Mark; Verellen, Dirk [Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); D' Haens, Jean [Department of Neurosurgery, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium); Storme, Guy [Department of Radiation Oncology, UZ Brussel, Vrije Universiteit Brussel (VUB), Laarbeeklaan 101, 1090 Brussels (Belgium)

    2011-11-15

    Purpose: To evaluate and compare outcomes for patients with vestibular schwannoma (VS) treated in a single institution with linac-based stereotactic radiosurgery (SRS) or by fractionated stereotactic radiotherapy (SRT). Methods and Materials: One hundred and nineteen patients (SRS = 78, SRT = 41) were treated. For both SRS and SRT, beam shaping is performed by a mini-multileaf collimator. For SRS, a median single dose of 12.5 Gy (range, 11-14 Gy), prescribed to the 80% isodose line encompassing the target, was applied. Of the 42 SRT treatments, 32 treatments consisted of 10 fractions of 3-4 Gy, and 10 patients received 25 sessions of 2 Gy, prescribed to the 100% with the 95% isodose line encompassing the planning target volume. Mean largest tumor diameter was 16.6 mm in the SRS and 24.6 mm in the SRT group. Local tumor control, cranial nerve toxicity, and preservation of useful hearing were recorded. Any new treatment-induced cranial nerve neuropathy was scored as a complication. Results: Median follow-up was 62 months (range, 6-136 months), 5 patients progressed, resulting in an overall 5-year local tumor control of 95%. The overall 5-year facial nerve preservation probability was 88% and facial nerve neuropathy was statistically significantly higher after SRS, after prior surgery, for larger tumors, and in Koos Grade {>=}3. The overall 5-year trigeminal nerve preservation probability was 96%, not significantly influenced by any of the risk factors. The overall 4-year probability of preservation of useful hearing (Gardner-Robertson score 1 or 2) was 68%, not significantly different between SRS or SRT (59% vs. 82%, p = 0.089, log rank). Conclusion: Linac-based RT results in good local control and acceptable clinical outcome in small to medium-sized vestibular schwannomas (VSs). Radiosurgery for large VSs (Koos Grade {>=}3) remains a challenge because of increased facial nerve neuropathy.

  14. The results of radiation therapy for intracranial meningiomas. With special reference to the natural course of the tumor size after radiotherapy

    International Nuclear Information System (INIS)

    Kobayashi, Katsuhiro; Murakami, Masao; Kubo, Takeshi; Kono, Koichi; Okamoto, Yoshiaki; Kuroda, Yasumasa

    1998-01-01

    Twenty-four cases with intracranial meningioma received radiation therapy from 1967 to 1995 at Tenri Hospital. Two received preoperative radiotherapy and 22 post operative radiotherapy. Of all, 11 were benign, 9 were malignant and 4 were reported only as meningioma. The extent of surgery consisted of total resection in 4, subtotal resection in 10, partial resection in 6, biopsy in 2, exploration in 1 and unknown in 1. Twelve were initial treatments and another 12 were salvage treatments. In all cases, radiation therapy was given a mean dose of 53.6 Gy with 6 or 10 MV X-rays using conventional fractionation. The mean follow-up interval is 56.7 months. Total cause specific survival at 5 and 10 years were 79% and 69%, respectively. The 10-year recurrence-free survival was 100% in benign and 61% in malignant meningiomas. The clinical course of benign meningiomas suggested the value of postoperative radiation therapy, but that of malignant meningiomas were divided into 2 groups, in which some one had recurrence just after completion of radiotherapy or another had local control. It seemed that there were some radio-resistant varieties in malignant meningiomas. The result of the consecutive follow-up by enhanced CT or MRI revealed benign meningiomas had a tendency to decrease in size in a long interval and some malignant meningiomas changed their size soon after radiotherapy. From analysis of our study we conclude that radiation therapy is a useful post-surgical treatment for intracranial meningiomas. (author)

  15. Clinical investigation of twice-a-day fractionated radiotherapy for T2 laryngeal cancer

    International Nuclear Information System (INIS)

    Karasawa, K.; Kaneyasu, Y.; Fukuhara, N.; Kita-Okawa, M.; Okawa, T.

    1996-01-01

    Purpose/objective: To improve the local control rate while minimizing the complication rate in the treatment of T2 laryngeal cancer, we conducted a Phase II trial of twice-a-day fractionated radiotherapy (TDFR) and compared the results with those of historical control treated by conventional radiotherapy. Materials and Methods: Between 1966 and 1995, 126 cases with T2 laryngeal cancer were treated by radiotherapy in our department by Cobalt equipment. Median field sige was 42cm 2 . Since 1986, we started TDFR. Fifty-eight cases were treated by TDFR, among them there were 6 cases of supraglottic lesion, 49 cases of glottic, and 3 cases of subglottic. Their age ranged from 47 to 82 (mean 64), and all but 1 cases were male. They were irradiated with a fraction dose of 1.5 Gy twice a day at least 6 hours apart, 10 times a week to a total dosage of 66 - 78 Gy (mean 69Gy) in 30 to 53 days (median 43 days). Fifty-four (93 %) of the cases needed a split during radiotherapy for acute mucosal reaction. The other 68 cases were treated by conventional radiotherapy (control group). There were 8 cases of supraglottic lesion, 57 of glottic, and 3 of subglottic. Their age ranged from 33 to 86 (mean 62), and 62 cases (91 %) were male. They were irradiated with a fraction dose of 1.8 Gy (38 cases) or 2 Gy (30 cases) to a total dosage of 59 - 72Gy (mean 66 Gy) in 43 - 69 days (median 51 days). Thirteen (19 %) of the cases needed a split during radiotherapy. Acute and late reactions were graded into 4 grades and compared. Results: Five year actuarial local control rate was 79.0 % in the TDFR group and 75.6 % in the control group (n.s.). Five year actuarial survival rate was 79.7 % in the TDFR group and 77.7 % in the control group (n.s.). Five year actuarial cause-specific survival rate was 96.4 % in the TDFR group and 95.2 % in the control group (n.s.). Five year actuarial local control rate of glottic cases was 78.6 % in the TDFR group and 78.8 % in the control group (n.s.). As for

  16. Natural history of intracranial meningioma after radiotherapy

    International Nuclear Information System (INIS)

    Monzen, Yoshio

    1999-01-01

    The author examined the natural history of intracranial meningioma after radiotherapy using CT or MR imaging. Twenty patients with intracranial meningioma received radiotherapy from a high-energy linear accelerator (4-10 MV X rays) from 1980 to 1996. The total doses were 50 Gy to the tumor bed in single doses of 2 Gy in 5 weekly fractions. Meningiomas in 10 of 20 patients were reduced within 1 to 38 months after radiotherapy, the average being 11 months. The tumors were controlled for a median of 60 months after radiotherapy (range 19-126 months). Four other patients have shown no change in tumor size after radiotherapy. The tumors were controlled for a median of 70 months after radiotherapy (range 37-127 months). The other six patients have shown tumor growth within 3 to 25 months after radiotherapy, after which the tumors stopped growing for a median of 71 months (range 2-181 months). Neither tumor size nor histological type was related to response. The growth of tumors was controlled by radiotherapy for a median duration of 43 months in the meningothelial type, 52 months in the fibroblastic type, and 61 months in the transitional type. The median duration for all benign tumors was 52 months. A moderate correlation was noted between tumor response and functional outcome after radiotherapy in 9 patients with neurological deficits. The natural histories of intracranial meningiomas after radiotherapy were grouped into three categories. Some tumors showed no change in size over a long period. This was a characteristic response after radiotherapy that differed from that of other brain tumors. The results of this study provide important information for the follow-up of intracranial meningiomas after radiotherapy. (author)

  17. Effect of fractionated radiotherapy using a hypoxic cell radiosensitizer, RK-28, on experimental murine tumor

    International Nuclear Information System (INIS)

    Tanaka, Shukaku

    1990-01-01

    The effect of a hypoxic cell radiosensitizer RK-28, on fractionated radiotherapy was studied using mice with implanted tumors. Experimental animal tumors were third generation isoplants of a mammary carcinoma which arose spontaneously in a C 3 H/He mouse. RK-28 was given to the mice at two dosages: 0.4 mg/g,b.wt. and 0.2 mg/g.b.wt. Total dose of irradiation was 20 Gy which was divided into the first 10 Gy irradiation and the second 10 Gy performed after a proper time interval such as 1, 24, 48 and 72 hours after the first 10 Gy irradiation. Tumor growth was evaluated by TGT 50 /3 times, which was defined as the time required for 50% of the tumors to regrow to the 3 times value of its initial volume. Tumor volume was measured every day and TGT 50 /3 times was calculated by logit analysis method. No significant differences were found in the TGT 50 /3 times among the groups treated by radiation alone, those treated by RK-administration alone and those without any treatment. TGT 50 value of control group without any treatment was 3.40 (days). TGT 50 value of another group treated by RK-28 alone was 3.46. and TGT 50 value of 20 Gy X-ray irradiation alone was 10.23. Under the fractionated X-ray irradiation alone, TGT 50 values of the various time interval such as 9, 14, 48 and 72 hours were 11.26, 10.42, 12.14 and 1.10. Under the combined treatment of the fractionated X-ray irradiation and RK-28 administration, TGT 50 values were 17.84, 16.42, 16.59 and 17.49. These TGT 50 /3 times values showed that RK-28 had a radiosensitizing effect when given with fractionated radiotherapy even at lower doses of RK-28 administration and radiation. Therefore, it was suggested that fractionated radiotherapy using RK-28 was useful in the cancer treatment. (author) 52 refs

  18. Neuropsychological outcome after fractionated stereotactic radiotherapy (FSRT) for base of skull meningiomas: a prospective 1-year follow-up

    International Nuclear Information System (INIS)

    Steinvorth, Sarah; Welzel, Grit; Fuss, Martin; Debus, Juergen; Wildermuth, Susanne; Wannenmacher, Michael; Wenz, Frederik

    2003-01-01

    Purpose: The purpose of this study was to evaluate the cognitive outcome after fractionated stereotactic radiotherapy (FSRT) in patients with base of skull meningiomas. Methods and material: A total of 40 patients with base of skull meningiomas were neuro psychologically evaluated before, after the first fraction (1.8 Gy), at the end of FSRT (n=37), 6 weeks (n=24), 6 (n=18) and 12 months (n=14) after FSRT. A comprehensive test battery including assessment of general intelligence, attention and memory functions was used. Alternate forms were used and current mood state was controlled. Results: After the first fraction a transient decline in memory function and simultaneous improvements in attention functions were observed. No cognitive deteriorations were seen during further follow-up, but increases in attention and memory functions were observed. Mood state improved after the first fraction, at the end of radiotherapy and 6 weeks after radiotherapy. Conclusion: The present data support the conclusion that the probability for the development of permanent cognitive dysfunctions appears to be very low after FSRT. The transient memory impairments on day 1 are interpreted as most likely related to an increase of a preexisting peritumoral edema, whereas the significant acute improvements in attention functions are interpreted as practice effects. An analysis of localization specific effects of radiation failed to show clear hemisphere specific cognitive changes

  19. Determination of reactivity rates of silicate particle-size fractions

    Directory of Open Access Journals (Sweden)

    Angélica Cristina Fernandes Deus

    2014-04-01

    Full Text Available The efficiency of sources used for soil acidity correction depends on reactivity rate (RR and neutralization power (NP, indicated by effective calcium carbonate (ECC. Few studies establish relative efficiency of reactivity (RER for silicate particle-size fractions, therefore, the RER applied for lime are used. This study aimed to evaluate the reactivity of silicate materials affected by particle size throughout incubation periods in comparison to lime, and to calculate the RER for silicate particle-size fractions. Six correction sources were evaluated: three slags from distinct origins, dolomitic and calcitic lime separated into four particle-size fractions (2, 0.84, 0.30 and <0.30-mm sieves, and wollastonite, as an additional treatment. The treatments were applied to three soils with different texture classes. The dose of neutralizing material (calcium and magnesium oxides was applied at equal quantities, and the only variation was the particle-size material. After a 90-day incubation period, the RER was calculated for each particle-size fraction, as well as the RR and ECC of each source. The neutralization of soil acidity of the same particle-size fraction for different sources showed distinct solubility and a distinct reaction between silicates and lime. The RER for slag were higher than the limits established by Brazilian legislation, indicating that the method used for limes should not be used for the slags studied here.

  20. The future of breast cancer radiotherapy: From one size fits all to taylor-made treatment; L'avenir de la radiotherapie du cancer du sein: de la taille unique au sur-mesure

    Energy Technology Data Exchange (ETDEWEB)

    Hennequin, C. [Service de cancerologie-radiotherapie, hopital Saint-Louis, 1, avenue Claude-Vellefaux, 75475 Paris (France); Azria, D. [Departement de cancerologie radiotherapie, CRLC Val-d' Aurelle-Paul-Lamarque, rue Croix-Verte, 34298 Montpellier cedex 5 (France); Universite de Montpellier I, 5, boulevard Henri-IV, CS 19044, 34967 Montpellier cedex 2 (France); Inserm U896, institut de recherche en cancerologie de Montpellier, CRLC Val-d' Aurelle-Paul-Lamarque, rue Croix-Verte, 34298 Montpellier cedex 5 (France)

    2011-10-15

    Various subgroups of breast tumours have been identified during the last 10 years according to the risk of local relapse. Prognostic factors for local relapse are age, surgical margins, tumour size, Her2 expression and hormonal receptors status. For tumours with a high risk of local relapse, an increased in boost dose or the addition of new drugs (trastuzumab, anti-angiogenics, PARP inhibitors) could be considered. For low risk tumours, hypo-fractionated, accelerated partial breast and intraoperative radiotherapy are being evaluated. The classical schedule (45-50 Gy to the whole gland followed by a boost dose of 16 Gy) is no longer the universal rule. Treatment individualization, according to clinical and biological characteristics of the tumour and - possibly - to the radiobiological profile of the patient, is likely to be the future of breast cancer radiotherapy. (authors)

  1. Fractionated vs. single-fraction stereotactic radiotherapy in patients with vestibular schwannoma. Hearing preservation and patients' self-reported outcome based on an established questionnaire

    International Nuclear Information System (INIS)

    Kessel, Kerstin A.; Fischer, Hanna; Vogel, Marco M.E.; Combs, Stephanie E.; Oechsner, Markus; Bier, Henning; Meyer, Bernhard

    2017-01-01

    Stereotactic radiotherapy (RT) has been established as a valid treatment alternative in patients with vestibular schwannoma (VS). There is ongoing controversy regarding the optimal fractionation. Hearing preservation may be the primary goal for patients with VS, followed by maintenance of quality of life (QoL). From 2002 to 2015, 184 patients with VS were treated with radiosurgery (RS) or fractionated stereotactic radiotherapy (FSRT). A survey on current symptoms and QoL was conducted between February and June 2016. Median follow-up after RT was 7.5 years (range 0-14.4 years). Mean overall survival (OS) after RT was 31.1 years, with 94 and 87% survival at 5 and 10 years, respectively. Mean progression-free survival (PFS) was 13.3 years, with 5- and 10-year PFS of 92%. Hearing could be preserved in RS patients for a median of 36.3 months (range 2.3-13.7 years). Hearing worsened in 17 (30%) cases. Median hearing preservation for FSRT was 48.7 months (range 0.0-13.8 years); 29 (23%) showed hearing deterioration. The difference in hearing preservation was not significant between RS and FSRT (p = 0.3). A total of 123/162 patients participated in the patient survey (return rate 76%). The results correlate well with the information documented in the patient files for tinnitus and facial and trigeminal nerve toxicity. Significant differences appeared regarding hearing impairment, gait uncertainty, and imbalance. These data confirm that RS and FSRT are comparable in terms of local control for VS. RS should be reserved for smaller lesions, while FSRT can be offered independently of tumor size. Patient self-reported outcome during follow-up is of high value. The established questionnaire could be validated in the independent cohort. (orig.) [de

  2. The field size matters: low dose external beam radiotherapy for thumb carpometacarpal osteoarthritis : Importance of field size.

    Science.gov (United States)

    Kaltenborn, Alexander; Bulling, Elke; Nitsche, Mirko; Carl, Ulrich Martin; Hermann, Robert Michael

    2016-08-01

    The purpose of this work was to evaluate the efficacy of low-dose radiotherapy (RT) for thumb carpometacarpal osteoarthritis (rhizarthrosis). The responses of 84 patients (n = 101 joints) were analyzed 3 months after therapy (n = 65) and at 12 months (n = 27). Patients were treated with 6 fractions of 1 Gy, two times a week, with a linear accelerator. At the end of therapy, about 70 % of patients reported a response (partial remission or complete remission), 3 months later about 60 %, and 1 year after treatment 70 %. In univariate regression analysis, higher patient age and field size greater than 6 × 4 cm were associated with response to treatment, while initial increase of pain under treatment was predictive for treatment failure. Duration of RT series (more than 18 days), gender, time of symptoms before RT, stress pain or rest pain, or prior ortheses use, injections, or surgery of the joint were not associated with treatment efficacy. In multivariate regression analysis, only field size and initial pain increase were highly correlated with treatment outcome. In conclusion, RT represents a useful treatment option for patients suffering from carpometacarpal osteoarthritis. In contrast to other benign indications, a larger field size (>6 × 4 cm) seems to be more effective than smaller fields and should be evaluated in further prospective studies.

  3. Intra-fractional bladder motion and margins in adaptive radiotherapy for urinary bladder cancer

    DEFF Research Database (Denmark)

    Grønborg, Caroline; Vestergaard, Anne; Høyer, Morten

    2015-01-01

    and to estimate population-based and patient-specific intra-fractional margins, also relevant for a future re-optimisation strategy. MATERIAL AND METHODS: Nine patients treated in a clinical phase II ART trial of daily plan selection for bladder cancer were included. In the library plans, 5 mm isotropic margins......BACKGROUND: The bladder is a tumour site well suited for adaptive radiotherapy (ART) due to large inter-fractional changes, but it also displays considerable intra-fractional motion. The aim of this study was to assess target coverage with a clinically applied method for plan selection ART...... were added to account for intra-fractional changes. Pre-treatment and weekly repeat magnetic resonance imaging (MRI) series were acquired in which a full three-dimensional (3D) volume was scanned every second min for 10 min (a total of 366 scans in 61 series). Initially, the bladder clinical target...

  4. Dose mapping sensitivity to deformable registration uncertainties in fractionated radiotherapy – applied to prostate proton treatments

    International Nuclear Information System (INIS)

    Tilly, David; Tilly, Nina; Ahnesjö, Anders

    2013-01-01

    Calculation of accumulated dose in fractionated radiotherapy based on spatial mapping of the dose points generally requires deformable image registration (DIR). The accuracy of the accumulated dose thus depends heavily on the DIR quality. This motivates investigations of how the registration uncertainty influences dose planning objectives and treatment outcome predictions. A framework was developed where the dose mapping can be associated with a variable known uncertainty to simulate the DIR uncertainties in a clinical workflow. The framework enabled us to study the dependence of dose planning metrics, and the predicted treatment outcome, on the DIR uncertainty. The additional planning margin needed to compensate for the dose mapping uncertainties can also be determined. We applied the simulation framework to a hypofractionated proton treatment of the prostate using two different scanning beam spot sizes to also study the dose mapping sensitivity to penumbra widths. The planning parameter most sensitive to the DIR uncertainty was found to be the target D 95 . We found that the registration mean absolute error needs to be ≤0.20 cm to obtain an uncertainty better than 3% of the calculated D 95 for intermediate sized penumbras. Use of larger margins in constructing PTV from CTV relaxed the registration uncertainty requirements to the cost of increased dose burdens to the surrounding organs at risk. The DIR uncertainty requirements should be considered in an adaptive radiotherapy workflow since this uncertainty can have significant impact on the accumulated dose. The simulation framework enabled quantification of the accuracy requirement for DIR algorithms to provide satisfactory clinical accuracy in the accumulated dose

  5. Fractionated stereotactically guided radiotherapy for pharmacoresistant epilepsy; Fraktionierte, stereotaktisch gefuehrte Radiotherapie der pharmakoresistenten Epilepsie

    Energy Technology Data Exchange (ETDEWEB)

    Grabenbauer, G.G.; Reinhold, C.; Lambrecht, U.; Sauer, R. [Klinik und Poliklinik fuer Strahlentherapie, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Kerling, F.; Pauli, E.; Stefan, H. [Neurologische Klinik, Abt. Epileptologie, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Mueller, R.G. [Inst. fuer Medizinische Physik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany); Ganslandt, O. [Neurochirurgische Klinik, Friedrich-Alexander-Univ. Erlangen-Nuernberg, Erlangen (Germany)

    2003-01-01

    Aim: This prospective study evaluated the efficiency of fractionated stereotactically guided radiotherapy as a treatment of pharmacoresistant temporal lobe epilepsy. Patients and Methods: Inclusion criteria were patients aged between 17 and 65 years with one-sided temporally located focus, without sufficient epilepsy control by, antiepileptic drugs or neurosurgery. Between 1997 and 1999, two groups of six patients each were treated with 21 Gy (7 times 3 Gy) and 30 Gy (15 times 2 Gy). Study end points were seizure frequency, intensity, seizure length and neuropsychological parameters. Results: All patients experienced a marked reduction in seizure frequency. The mean reduction of seizures was 37% (range 9-77%, i.e. seizures reduced from a monthly mean number of 11.75 to 7.52) at 18 months following radiation treatment and 46% (23-94%, i.e. 0.2-23 seizures per month) during the whole follow-up time. Seizure length was reduced in five out of eleven patients and intensity of seizures in seven out of eleven patients. Conclusion: Radiotherapy was identified as safe and effective for pharmacoresistant epilepsy since a very good reduction of seizure frequency was observed. It is no substitute for regular use of antiepileptic drugs, but means an appropriate alternative for patients with contraindication against neurosurgery or insufficient seizure reduction after neurosurgery. (orig.) [German] Ziel: Diese prospektive Studie untersuchte die Effizienz einer fraktionierten stereotaktischen Radiotherapie (RT) bei therapieresistenter Temporallappenepilepsie. Patienten und Methoden: Einschlusskriterien waren Patienten im Alter von 17 bis 65 Jahren, die weder medikamentoes noch epilepsiechirurgisch anfallsfrei wurden und einen einseitigen Fokus aufwiesen. Zwei Patientenkohorten zu je sechs Patienten wurden zwischen 1997 und 1999 einer fraktionierten, stereotaktisch gefuehrten Radiotherapie mit 21 Gy (7 x 3 Gy) bzw. 30 Gy (15 x 2 Gy) unterzogen. Endpunkte der Untersuchung waren

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  7. Fractionated stereotactic conformal radiotherapy following conservative surgery in the control of craniopharyngiomas

    International Nuclear Information System (INIS)

    Minniti, Giuseppe; Saran, Frank; Traish, Daphne; Soomal, Rubin; Sardell, Susan; Gonsalves, Adam; Ashley, Susan; Warrington, Jim; Burke, Kevin; Mosleh-Shirazi, Amin; Brada, Michael

    2007-01-01

    Purpose: To describe the technique and results of stereotactically guided conformal radiotherapy (SCRT) in patients with craniopharyngioma after conservative surgery. Methods and materials: Thirty-nine patients with craniopharyngioma aged 3-68 years (median age 18 years) were treated with SCRT between June 1994 and January 2003. All patients were referred for radiotherapy after undergoing one or more surgical procedures. Treatment was delivered in 30-33 daily fractions over 6-6.5 weeks to a total dose of 50 Gy using 6 MV photons. Outcome was assessed prospectively. Results: At a median follow-up of 40 months (range 3-88 months) the 3- and 5-year progression-free survival (PFS) was 97% and 92%, and 3- and 5-year survival 100%. Two patients required further debulking surgery for progressive disease 8 and 41 months after radiotherapy. Twelve patients (30%) had acute clinical deterioration due to cystic enlargement of craniopharyngioma following SCRT and required cyst aspiration. One patient with severe visual impairment prior to radiotherapy had visual deterioration following SCRT. Seven out of 10 patients with a normal pituitary function before SCRT had no endocrine deficits following treatment. Conclusion: SCRT as a high-precision technique of localized RT is suitable for the treatment of incompletely excised craniopharyngioma. The local control, toxicity and survival outcomes are comparable to results reported following conventional external beam RT. Longer follow-up is required to assess long-term efficacy and toxicity, particularly in terms of potential reduction in treatment related late toxicity

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

    International Nuclear Information System (INIS)

    Droege, L.H.; Hinsche, T.; Hess, C.F.; Wolff, H.A.; Canis, M.; Alt-Epping, B.

    2014-01-01

    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.)

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  10. Long-term results of radiotherapy for pituitary adenomas. Evaluation of tumor control and hypopituitarism after radiotherapy

    International Nuclear Information System (INIS)

    Tsuchida, Emiko; Sakai, Kunio; Matsumoto, Yasuo; Sugita, Tadashi; Sasamoto, Ryuta

    1999-01-01

    To evaluate the results of conventional radiotherapy for pituitary adenomas assessed with computed tomography (CT) or magnetic resonance imaging (MRI). Endpoints include tumor control, normalization of hormone levels in functioning adenomas, and hypopituitarism after radiotherapy as an adverse effect. Forty-two patients were treated with radiotherapy from 1982 to 1995 at Niigata University Hospital. Forty patients were irradiated after surgery because of residual adenomas in 33 patients and tumor regrowth in 7 patients. One patient was treated with radiotherapy alone, and the remaining 1 patient was treated with preoperative radiotherapy. Tumor size and extension were evaluated using CT or MRI, and all tumors were macroadenomas. They consisted of 18 non-functioning and 24 functioning adenomas (growth hormone (GH)-secreting: 11, prolactinomas: 7, concomitant GH and prolactin (PRL)-secreting: 5, gonadotropin-secreting: 1). Treatment was given in 200 cGy daily fraction size and a total dose of 50 Gy was given to most patients. Sixteen patients with GH- and/or PRL-secreting adenomas received bromocriptine. Tumor progression was determined by increase in tumor size as shown by CT or MRI. Hypopituitarism after radiotherapy was evaluated using the functions of corticotropin (ACTH), thyrotropin (TSH), and gonadotropin. Median follow-up time from the end of radiotherapy was 103 months. Tumor progression occurred in 2 out of 42 patients and 10-year progression-free rate for all patients was 93.7%. Normalization of GH levels was obtained in 12 of 16 GH-secreting adenomas with a mean time of 27 months after radiotherapy, and 9 of 12 PRL-secreting adenomas achieved normalization of PRL levels with a mean time of 34 months. One gonadotropin-secreting adenoma achieved normalization of gonadotropin level at 21 months after radiotherapy. The incidence of hypopituitarism after radiotherapy increased with time, and cumulative risk of deficiencies of ACTH, TSH, and gonadotropin at 10

  11. Effects of continuous hyperfractionated accelerated and conventionally fractionated radiotherapy on the parotid and submandibular salivary glands of rhesus monkeys

    International Nuclear Information System (INIS)

    Price, R.E.; Ang, K.K.; Stephens, L.C.; Peters, L.J.

    1995-01-01

    Radiotherapy is a major treatment modality for head and neck cancer. It is often not possible to exclude the salivary glands from the treatment fields. The unique susceptibility of the serous cells of the salivary glands to irradiation often results in xerostomia with ensuing secondary complications and discomfort to the patients. Recent reports have suggested that continuous hyperfractionated accelerated radiotherapy (CHART) can lead to considerably less reduction in salivary flow of the parotid salivary gland than conventional radiotherapy. This study was undertaken to assess histologic changes of salivary glands induced by CHART and conventional radiation fractionation schedules. The parotid and submandibular salivary glands of adult rhesus monkeys were irradiated with cobalt-60 γ radiation at 50 Gy/20 fractions/4 weeks, 55 Gy/25 fractions/5 weeks, or 54 Gy/36 fractions/12 days (CHART). Salivary tissues were harvested at 16 weeks following irradiation and evaluated histopathologically. Microscopically, the glands receiving 50 Gy, 55 Gy, or CHART were virtually indistinguishable. There was severe atrophy and fibrosis of all glands. Quantitative analysis revealed that 50 Gy, 55 Gy, and CHART induced a reduction of serous acini in parotid glands by 86.4%, 84.8%, and 88.8%, respectively. In submandibular glands, serous acini were reduced by 99.4%, 99.0%, and 100%, respectively. The corresponding reduction in mucous acini were 98.4%, 98.4%, and 99.2%, respectively. These histopathologic and quantitative morphologic studies show that the magnitude of serous gland atrophy in the parotid and submandibular salivary glands of rhesus monkeys was similar at 16 weeks after receiving 50 Gy in 20 fractions, 55 Gy in 25 fractions, or CHART

  12. Heavy metals in the finest size fractions of road-deposited sediments.

    Science.gov (United States)

    Lanzerstorfer, Christof

    2018-08-01

    The concentration of heavy metals in urban road-deposited sediments (RDS) can be used as an indicator for environmental pollution. Thus, their occurrence has been studied in whole road dust samples as well as in size fractions obtained by sieving. Because of the limitations of size separation by sieving little information is available about heavy metal concentrations in the road dust size fractions heavy metals concentrations and size distribution. According to the Geoaccumulation Index the pollution of the road dust samples deceased in the following order: Sb » As > Cu ≈ Zn > Cr > Cd ≈ Pb ≈ Mn > Ni > Co ≈ V. For all heavy metals the concentration was higher in the fine size fractions compared to the coarse size fractions, while the concentration of Sr was size-independent. The enrichment of the heavy metals in the finest size fraction compared to the whole RDS  Sb > (Cu) ≈ Zn ≈ Pb > As ≈ V » Mn. The approximation of the size dependence of the concentration as a function of the particle size by power functions worked very well. The correlation between particle size and concentration was high for all heavy metals. The increased heavy metals concentrations in the finest size fractions should be considered in the evaluation of the contribution of road dust re-suspension to the heavy metal contamination of atmospheric dust. Thereby, power functions can be used to describe the size dependence of the concentration. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Radiotherapy in the management of aggressive fibromatosis

    International Nuclear Information System (INIS)

    Atahan, I.L.; Akyol, F.; Zorlu, F.; Guerkaynak, M.

    1989-01-01

    Four case reports are summarised concerning the management of aggressive fibromatosis in children and adolescents up to the age of 15. It was concluded that radiotherapy should be reserved for recurrences or inoperable cases. A dose of 5000-6000 cGy in 25-30 fractions depending on age of patient, site, and size of tumour is necessary, since most surgical recurrences appear in 12 months, all cases with positive surgical margins should receive doses in the range 4000-4500 cGy for microscopic disease. Radiotherapy-chemotherapy combinations can also be used. (UK)

  14. Hypo-fractionated radiotherapy of breast cancer: long term results of a set of 80 cases treated in the radiotherapy department of the Oran university hospital

    International Nuclear Information System (INIS)

    Boukerche, A.; Yahia, A.; Madouri, R.; Belmiloud, H.; Dali-Youcef, A.F.

    2011-01-01

    The authors report the assessment of the local and locoregional control and of the acute and late toxicity of adjuvant hypo-fractionated radiotherapy in breast cancer treatment. During 1998, 80 women have been treated by conservative or radical surgery and hypo-fractionated tele-cobalto-therapy (36 Gy in five fractions of 3 Gy a week, and a boost of 15 Gy in five fractions in case of conservative surgery). Results are discussed in terms of local and locoregional recurrence, tolerance, late toxicity, global survival, and tumour classification. The irradiation scheme seems perfectly achievable but a greater number of patients and a longer follow-up are required to better assess the efficiency and aesthetic results. Short communication

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

    Science.gov (United States)

    Dröge, L H; Hinsche, T; Canis, M; Alt-Epping, B; Hess, C F; Wolff, H A

    2014-02-01

    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.

  16. How does imaging frequency and soft tissue motion affect the PTV margin size in partial breast and boost radiotherapy?

    International Nuclear Information System (INIS)

    Harris, Emma J.; Donovan, Ellen M.; Coles, Charlotte E.; Boer, Hans C.J. de; Poynter, Andrew; Rawlings, Christine; Wishart, Gordon C.; Evans, Philip M.

    2012-01-01

    Purpose: This study investigates (i) the effect of verification protocols on treatment accuracy and PTV margins for partial breast and boost breast radiotherapy with short fractionation schema (15 fractions), (ii) the effect of deformation of the excision cavity (EC) on PTV margin size, (iii) the imaging dose required to achieve specific PTV margins. Methods and materials: Verification images using implanted EC markers were studied in 36 patients. Target motion was estimated for a 15 fraction partial breast regimen using imaging protocols based on on-line and off-line motion correction strategies (No Action Level (NAL) and the extended NAL (eNAL) protocols). Target motion was used to estimate a PTV margin for each protocol. To evaluate treatment errors due to deformation of the excision cavity, individual marker positions were obtained from 11 patients. The mean clip displacement and daily variation in clip position during radiotherapy were determined and the contribution of these errors to PTV margin calculated. Published imaging dose data were used to estimate total dose for each protocol. Finally the number of images required to obtain a specific PTV margin was evaluated and hence, the relationship between PTV margins and imaging dose was investigated. Results: The PTV margin required to account for excision cavity motion, varied between 10.2 and 2.4 mm depending on the correction strategy used. Average clip movement was 0.8 mm and average variation in clip position during treatment was 0.4 mm. The contribution to PTV margin from deformation was estimated to be small, less than 0.2 mm for both off-line and on-line correction protocols. Conclusion: A boost or partial breast PTV margin of ∼10 mm, is possible with zero imaging dose and workload, however, patients receiving boost radiotherapy may benefit from a margin reduction of ∼4 mm with imaging doses from 0.4 cGy to 25 cGy using an eNAL protocol. PTV margin contributions from deformation errors are likely

  17. Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

    Energy Technology Data Exchange (ETDEWEB)

    Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M. [Radiotherapy Centre West, The Hague (Netherlands); Molenaar, R. [Diaconessenhuis, Leiden (Netherlands). Dept. of Neurology; Lycklama a Nijeholt, G. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Radiology; Vecht, C. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Neurology; Struikmans, H. [Radiotherapy Centre West, The Hague (Netherlands); Leiden Univ. Medical Centre (Netherlands). Dept. of Radiotherapy; Kal, H.B.

    2012-08-15

    Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm{sup 3} or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

  18. Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

    International Nuclear Information System (INIS)

    Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M.; Molenaar, R.; Lycklama a Nijeholt, G.; Vecht, C.; Struikmans, H.; Leiden Univ. Medical Centre; Kal, H.B.

    2012-01-01

    Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm 3 or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

  19. Size fractionation of waste-to-energy boiler ash enables separation of a coarse fraction with low dioxin concentrations.

    Science.gov (United States)

    Weidemann, E; Allegrini, E; Fruergaard Astrup, T; Hulgaard, T; Riber, C; Jansson, S

    2016-03-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) formed in modern Waste-to-Energy plants are primarily found in the generated ashes and air pollution control residues, which are usually disposed of as hazardous waste. The objective of this study was to explore the occurrence of PCDD/F in different grain size fractions in the boiler ash, i.e. ash originating from the convection pass of the boiler. If a correlation between particle size and dioxin concentrations could be found, size fractionation of the ashes could reduce the total amount of hazardous waste. Boiler ash samples from ten sections of a boiler's convective part were collected over three sampling days, sieved into three different size fractions - 0.355 mm - and analysed for PCDD/F. The coarse fraction (>0.355 mm) in the first sections of the horizontal convection pass appeared to be of low toxicity with respect to dioxin content. While the total mass of the coarse fraction in this boiler was relatively small, sieving could reduce the amount of ash containing toxic PCDD/F by around 0.5 kg per tonne input waste or around 15% of the collected boiler ash from the convection pass. The mid-size fraction in this study covered a wide size range (0.09-0.355 mm) and possibly a low toxicity fraction could be identified by splitting this fraction into more narrow size ranges. The ashes exhibited uniform PCDD/F homologue patterns which suggests a stable and continuous generation of PCDD/F. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Results of fractionated stereotactic radiotherapy with linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Masahiko; Watanabe, Sadao [Aomori Prefectural Central Hospital (Japan); Mariya, Yasushi [and others

    1997-03-01

    A lot of clinical data about stereotactic radiotherapy (SRT) were reported, however, standard fractionated schedules were not shown. In this paper, our clinical results of SRT, 3 fractions of 10 Gy, are reported. Between February 1992 and March 1995, we treated 41 patients with 7 arteriovenous malformations and 41 intracranial tumors using a stereotactic technique implemented by a standard 10MV X-ray linear accelerator. Average age was 47.4 years (range 3-80 years) and average follow-up time was 16.7 months (range 3.5-46.1 months). The patients received 3 fractions of 10 Gy for 3 days delivered by multiple arc narrow beams under 3 cm in width and length. A three-pieces handmade shell was used for head fixation without any anesthetic procedures. Three-dimensional treatment planning system (Focus) was applied for the dose calculation. All patients have received at least one follow-up radiographic study and one clinical examination. In four of the 7 patients with AVM the nidus has become smaller, 9 of the 21 patients with benign intracranial tumors and 9 of the 13 patients with intracranial malignant tumors have shown complete or partial response to the therapy. In 14 patients, diseases were stable or unevaluable due to the short follow-up time. In 5 patients (3 with astrocytoma, 1 each with meningioma and craniopharyngioma), diseases were progressive. Only 1 patient with falx meningioma had minor complication due to the symptomatic brain edema around the tumor. Although, further evaluation of target control (i.e. tumor and nidus) and late normal tissue damage is needed, preliminary clinical results indicate that SRT with our methods is safe and effective. (author)

  1. Radiotherapy for pain management of bone metastases

    Energy Technology Data Exchange (ETDEWEB)

    Rezende Junior, Ismar de; Mattos, Marcos Duarte de; Nakamura, Ricardo; Lemes Junior, Joaquim; Vanzelli, Talita Lozano, E-mail: rezende.med@terra.com.br [Radioterapia do Hospital de Cancer de Barretos, SP (Brazil)

    2011-07-01

    Purpose: This is the first Brazilian study intended to evaluate the response of pain relief with radiotherapy in three different fractionation and the clinical differences in managing pain in patients with painful bone metastases. Methods: Prospective study of patients with painful bone metastases referred to the Radiotherapy Sector of the Hospital de Cancer de Barretos for pain-relieving radiotherapy between March and December 2010. It is known that radiotherapy seems to alter the activation of osteoclast-mediated bone resorption, relieving pain in cases of painful bone metastases. Patients were assessed in relation to the status of pain intensity before and after the initiation of radiotherapy. Either a single fraction of 8Gy, five fractions of 4Gy or ten fractions of 3Gy were given. A visual analog scale (VAS) was applied by doctors, nurses and nursing technicians to assess pain intensity at each session of radiotherapy, and follow-up at 8, 30 and 90 days from the end of treatment. Results: We evaluated 92 consecutive patients, 48 male and 44 female, with a median age of 58 years. We found that 14% of patients referred from the Palliative Care or Clinical Oncology sectors need better pharmacological analgesia due to severe pain, compared with 40.5% of patients from the other sectors (p = 0.004). We also found that the onset of pain relief to patients receiving 10 fractions of 300cGy analgesia without changing the pre-radiotherapy analgesia occurred with significance after the fifth fraction. Improvement in pain experienced within 90 days of follow-up was found in eighty percent of patients, independent of fractionated radiotherapy, site of metastases and the clinical condition of the patient. Discussion/Conclusion: The Palliative Care and Clinical Oncology sectors expressed greater concern in regards to analgesia for the patient with painful bone metastases. Radiotherapy is an effective pain-relieving treatment in different fractionation studied, even though the

  2. Radiotherapy for pain management of bone metastases

    International Nuclear Information System (INIS)

    Rezende Junior, Ismar de; Mattos, Marcos Duarte de; Nakamura, Ricardo; Lemes Junior, Joaquim; Vanzelli, Talita Lozano

    2011-01-01

    Purpose: This is the first Brazilian study intended to evaluate the response of pain relief with radiotherapy in three different fractionation and the clinical differences in managing pain in patients with painful bone metastases. Methods: Prospective study of patients with painful bone metastases referred to the Radiotherapy Sector of the Hospital de Cancer de Barretos for pain-relieving radiotherapy between March and December 2010. It is known that radiotherapy seems to alter the activation of osteoclast-mediated bone resorption, relieving pain in cases of painful bone metastases. Patients were assessed in relation to the status of pain intensity before and after the initiation of radiotherapy. Either a single fraction of 8Gy, five fractions of 4Gy or ten fractions of 3Gy were given. A visual analog scale (VAS) was applied by doctors, nurses and nursing technicians to assess pain intensity at each session of radiotherapy, and follow-up at 8, 30 and 90 days from the end of treatment. Results: We evaluated 92 consecutive patients, 48 male and 44 female, with a median age of 58 years. We found that 14% of patients referred from the Palliative Care or Clinical Oncology sectors need better pharmacological analgesia due to severe pain, compared with 40.5% of patients from the other sectors (p = 0.004). We also found that the onset of pain relief to patients receiving 10 fractions of 300cGy analgesia without changing the pre-radiotherapy analgesia occurred with significance after the fifth fraction. Improvement in pain experienced within 90 days of follow-up was found in eighty percent of patients, independent of fractionated radiotherapy, site of metastases and the clinical condition of the patient. Discussion/Conclusion: The Palliative Care and Clinical Oncology sectors expressed greater concern in regards to analgesia for the patient with painful bone metastases. Radiotherapy is an effective pain-relieving treatment in different fractionation studied, even though the

  3. 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....

  4. Gemcitabine Chemotherapy and Single-Fraction Stereotactic Body Radiotherapy for Locally Advanced Pancreatic Cancer

    International Nuclear Information System (INIS)

    Schellenberg, Devin; Goodman, Karyn A.; Lee, Florence; Chang, Stephanie; Kuo, Timothy; Ford, James M.; Fisher, George A.; Quon, Andrew; Desser, Terry S.; Norton, Jeffrey; Greco, Ralph; Yang, George P.; Koong, Albert C.

    2008-01-01

    Purpose: Fractionated radiotherapy and chemotherapy for locally advanced pancreatic cancer achieves only modest local control. This prospective trial evaluated the efficacy of a single fraction of 25 Gy stereotactic body radiotherapy (SBRT) delivered between Cycle 1 and 2 of gemcitabine chemotherapy. Methods and Materials: A total of 16 patients with locally advanced, nonmetastatic, pancreatic adenocarcinoma received gemcitabine with SBRT delivered 2 weeks after completion of the first cycle. Gemcitabine was resumed 2 weeks after SBRT and was continued until progression or dose-limiting toxicity. The gross tumor volume, with a 2-3-mm margin, was treated in a single 25-Gy fraction by Cyberknife. Patients were evaluated at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT. Results: All 16 patients completed SBRT. A median of four cycles (range one to nine) of chemotherapy was delivered. Three patients (19%) developed local disease progression at 14, 16, and 21 months after SBRT. The median survival was 11.4 months, with 50% of patients alive at 1 year. Patients with normal carbohydrate antigen (CA)19-9 levels either at diagnosis or after Cyberknife SBRT had longer survival (p <0.01). Acute gastrointestinal toxicity was mild, with 2 cases of Grade 2 (13%) and 1 of Grade 3 (6%) toxicity. Late gastrointestinal toxicity was more common, with five ulcers (Grade 2), one duodenal stenosis (Grade 3), and one duodenal perforation (Grade 4). A trend toward increased duodenal volumes radiated was observed in those experiencing late effects (p = 0.13). Conclusion: SBRT with gemcitabine resulted in comparable survival to conventional chemoradiotherapy and good local control. However, the rate of duodenal ulcer development was significant

  5. Fractionated stereotactic radiotherapy boost for gynecologic tumors: An alternative to brachytherapy?

    International Nuclear Information System (INIS)

    Molla, Meritxell; Escude, Lluis D.; Nouet, Philippe; Popowski, Youri D.Sc.; Hidalgo, Alberto; Rouzaud, Michel; Linero, Dolores; Miralbell, Raymond

    2005-01-01

    Purpose: A brachytherapy (BT) boost to the vaginal vault is considered standard treatment for many endometrial or cervical cancers. We aimed to challenge this treatment standard by using stereotactic radiotherapy (SRT) with a linac-based micromultileaf collimator technique. Methods and Materials: Since January 2002, 16 patients with either endometrial (9) or cervical (7) cancer have been treated with a final boost to the areas at higher risk for relapse. In 14 patients, the target volume included the vaginal vault, the upper vagina, the parametria, or (if not operated) the uterus (clinical target volume [CTV]). In 2 patients with local relapse, the CTV was the tumor in the vaginal stump. Margins of 6-10 mm were added to the CTV to define the planning target volume (PTV). Hypofractionated dynamic-arc or intensity-modulated radiotherapy techniques were used. Postoperative treatment was delivered in 12 patients (2 x 7 Gy to the PTV with a 4-7-day interval between fractions). In the 4 nonoperated patients, a dose of 4 Gy/fraction in 5 fractions with 2 to 3 days' interval was delivered. Patients were immobilized in a customized vacuum body cast and optimally repositioned with an infrared-guided system developed for extracranial SRT. To further optimize daily repositioning and target immobilization, an inflated rectal balloon was used during each treatment fraction. In 10 patients, CT resimulation was performed before the last boost fraction to assess for repositioning reproducibility via CT-to-CT registration and to estimate PTV safety margins around the CTV. Finally, a comparative treatment planning study between BT and SRT was performed in 2 patients with an operated endometrial Stage I cancer. Results: No patient developed severe acute urinary or low-intestinal toxicity. No patient developed urinary late effects (>6 months). One patient with a vaginal relapse previously irradiated to the pelvic region presented with Grade 3 rectal bleeding 18 months after retreatment

  6. Proton minibeam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Girst, Stefanie

    2016-03-08

    The risk of developing adverse side effects in the normal tissue after radiotherapy is often limiting for the dose that can be applied to the tumor. Proton minibeam radiotherapy, a spatially fractionated radiotherapy method using sub-millimeter proton beams, similar to grid therapy or microbeam radiation radiotherapy (MRT) using X-rays, has recently been invented at the ion microprobe SNAKE in Munich. The aim of this new concept is to minimize normal tissue injuries in the entrance channel and especially in the skin by irradiating only a small percentage of the cells in the total irradiation field, while maintaining tumor control via a homogeneous dose in the tumor, just like in conventional broad beam radiotherapy. This can be achieved by optimizing minibeam sizes and distances according to the prevailing tumor size and depth such that after widening of the minibeams due to proton interactions in the tissue, the overlapping minibeams produce a homogeneous dose distribution throughout the tumor. The aim of this work was to elucidate the prospects of minibeam radiation therapy compared to conventional homogeneous broad beam radiotherapy in theory and in experimental studies at the ion microprobe SNAKE. Treatment plans for model tumors of different sizes and depths were created using the planning software LAPCERR, to elaborate suitable minibeam sizes and distances for the individual tumors. Radiotherapy-relevant inter-beam distances required to obtain a homogeneous dose in the target volume were found to be in the millimeter range. First experiments using proton minibeams of only 10 μm and 50 μm size (termed microchannels in the corresponding publication Zlobinskaya et al. 2013) and therapy-conform larger dimensions of 100 μm and 180 μm were performed in the artificial human in-vitro skin model EpiDermFT trademark (MatTek). The corresponding inter-beam distances were 500 μm, 1mm and 1.8 mm, respectively, leading to irradiation of only a few percent of the cells

  7. Functional imaging to monitor vascular and metabolic response in canine head and neck tumors during fractionated radiotherapy.

    Science.gov (United States)

    Rødal, Jan; Rusten, Espen; Søvik, Åste; Skogmo, Hege Kippenes; Malinen, Eirik

    2013-10-01

    Radiotherapy causes alterations in tumor biology, and non-invasive early assessment of such alterations may become useful for identifying treatment resistant disease. The purpose of the current work is to assess changes in vascular and metabolic features derived from functional imaging of canine head and neck tumors during fractionated radiotherapy. Material and methods. Three dogs with spontaneous head and neck tumors received intensity-modulated radiotherapy (IMRT). Contrast-enhanced cone beam computed tomography (CE-CBCT) at the treatment unit was performed at five treatment fractions. Dynamic (18)FDG-PET (D-PET) was performed prior to the start of radiotherapy, at mid-treatment and at 3-12 weeks after the completion of treatment. Tumor contrast enhancement in the CE-CBCT images was used as a surrogate for tumor vasculature. Vascular and metabolic tumor parameters were further obtained from the D-PET images. Changes in these tumor parameters were assessed, with emphasis on intra-tumoral distributions. Results. For all three patients, metabolic imaging parameters obtained from D-PET decreased from the pre- to the inter-therapy session. Correspondingly, for two of three patients, vascular imaging parameters obtained from both CE-CBCT and D-PET increased. Only one of the tumors showed a clear metabolic response after therapy. No systematic changes in the intra-tumor heterogeneity in the imaging parameters were found. Conclusion. Changes in vascular and metabolic parameters could be detected by the current functional imaging methods. Vascular tumor features from CE-CBCT and D-PET corresponded well. CE-CBCT is a potential method for easy response assessment when the patient is at the treatment unit.

  8. 331 cases of clinically node-negative supraglottic carcinoma of the larynx: a study of a modest size fixed field radiotherapy approach

    International Nuclear Information System (INIS)

    Sykes, Andrew J.; Slevin, Nicholas J.; Gupta, Nirmal K.; Brewster, Allison E.

    2000-01-01

    Purpose: For node-negative supraglottic carcinoma of the larynx, radiotherapy with surgery in reserve commonly provides very good results in terms of both local control and survival, while preserving function. However uncertainty exists over the treatment of the node-negative neck. Elective whole neck radiotherapy, while effective, may be associated with significant morbidity. The purpose of this study was to examine our practice of treating a modest size, fixed field to a high biologically effective dose and compare it with the patterns of recurrence from other centers that use different dose/volume approaches. Methods and Materials: Over a 10-year period 331 patients with node-negative supraglottic carcinoma of the larynx were treated with radiotherapy at the Christie Hospital Manchester. Patients were treated with doses of 50-55 Gy in 16 fractions over 3 weeks. Data were collected retrospectively for local and regional control, survival, and morbidity. Results: Overall local control, after surgical salvage in 17 cases, was 79% (T1-92%, T2-81%, T3-67%, T4-73%). Overall regional lymph node control, after surgical salvage in 13 cases, was 84% (T1-91%, T2-88%, T3-81%, T4-72%). Five-year crude survival was 50%, but after correcting for intercurrent deaths was 70% (T1-83%, T2-78%, T3-53%, T4-61%). Serious morbidity requiring surgery was seen in 7 cases (2.1%) and was related to prescribed dose (50 Gy-0%, 52.5 Gy-1.3%, 55 Gy-3.4%). Discussion: Our results confirm that treating a modest size, fixed field to a high biologically effective dose is highly effective. It enables preservation of the larynx in most cases, with acceptable regional control and no loss of survival compared to whole neck radiotherapy regimes

  9. Universal Survival Curve and Single Fraction Equivalent Dose: Useful Tools in Understanding Potency of Ablative Radiotherapy

    International Nuclear Information System (INIS)

    Park, Clint; Papiez, Lech; Zhang Shichuan; Story, Michael; Timmerman, Robert D.

    2008-01-01

    Purpose: Overprediction of the potency and toxicity of high-dose ablative radiotherapy such as stereotactic body radiotherapy (SBRT) by the linear quadratic (LQ) model led to many clinicians' hesitating to adopt this efficacious and well-tolerated therapeutic option. The aim of this study was to offer an alternative method of analyzing the effect of SBRT by constructing a universal survival curve (USC) that provides superior approximation of the experimentally measured survival curves in the ablative, high-dose range without losing the strengths of the LQ model around the shoulder. Methods and Materials: The USC was constructed by hybridizing two classic radiobiologic models: the LQ model and the multitarget model. We have assumed that the LQ model gives a good description for conventionally fractionated radiotherapy (CFRT) for the dose to the shoulder. For ablative doses beyond the shoulder, the survival curve is better described as a straight line as predicted by the multitarget model. The USC smoothly interpolates from a parabola predicted by the LQ model to the terminal asymptote of the multitarget model in the high-dose region. From the USC, we derived two equivalence functions, the biologically effective dose and the single fraction equivalent dose for both CFRT and SBRT. Results: The validity of the USC was tested by using previously published parameters of the LQ and multitarget models for non-small-cell lung cancer cell lines. A comparison of the goodness-of-fit of the LQ and USC models was made to a high-dose survival curve of the H460 non-small-cell lung cancer cell line. Conclusion: The USC can be used to compare the dose fractionation schemes of both CFRT and SBRT. The USC provides an empirically and a clinically well-justified rationale for SBRT while preserving the strengths of the LQ model for CFRT

  10. Tumor Localization Using Cone-Beam CT Reduces Setup Margins in Conventionally Fractionated Radiotherapy for Lung Tumors

    International Nuclear Information System (INIS)

    Yeung, Anamaria R.; Li, Jonathan G.; Shi Wenyin; Newlin, Heather E.; Chvetsov, Alexei; Liu, Chihray; Palta, Jatinder R.; Olivier, Kenneth

    2009-01-01

    Purpose: To determine whether setup margins can be reduced using cone-beam computed tomography (CBCT) to localize tumor in conventionally fractionated radiotherapy for lung tumors. Methods and Materials: A total of 22 lung cancer patients were treated with curative intent with conventionally fractionated radiotherapy using daily image guidance with CBCT. Of these, 13 lung cancer patients had sufficient CBCT scans for analysis (389 CBCT scans). The patients underwent treatment simulation in the BodyFix immobilization system using four-dimensional CT to account for respiratory motion. Daily alignment was first done according to skin tattoos, followed by CBCT. All 389 CBCT scans were retrospectively registered to the planning CT scans using automated soft-tissue and bony registration; the resulting couch shifts in three dimensions were recorded. Results: The daily alignment to skin tattoos with no image guidance resulted in systematic (Σ) and random (σ) errors of 3.2-5.6 mm and 2.0-3.5 mm, respectively. The margin required to account for the setup error introduced by aligning to skin tattoos with no image guidance was approximately 1-1.6 cm. The difference in the couch shifts obtained from the bone and soft-tissue registration resulted in systematic (Σ) and random (σ) errors of 1.5-4.1 mm and 1.8-5.3 mm, respectively. The margin required to account for the setup error introduced using bony anatomy as a surrogate for the target, instead of localizing the target itself, was 0.5-1.4 cm. Conclusion: Using daily CBCT soft-tissue registration to localize the tumor in conventionally fractionated radiotherapy reduced the required setup margin by up to approximately 1.5 cm compared with both no image guidance and image guidance using bony anatomy as a surrogate for the target.

  11. Late toxicity of radiotherapy in Hodgkin's disease. The role of fraction size

    Energy Technology Data Exchange (ETDEWEB)

    Cosset, J.M.; Henry-Amar, M.; Girinski, T.; Malaise, E.; Dupouy, N.; Dutreix, J.

    1988-01-01

    From 1972 to 1976 patients were irradiated for Hodgkin's disease using a modified fractionation schedule (3 fractions of 3.3 Gy per week) for operational reasons. From 1964 to 1971 and from 1977 to 1981, a more conventional regimen (4 fractions of 2.5 Gy per week) was used. The rates of the late complications in these two subsets of patients treated with different fractionation schedules at the same total dose of 40 Gy during the same overall time were compared. Mediastinitis was observed in 19% of of the '4x2.5 Gy/week' group versus 56% in the '3x3.3 Gy/week' group. Pericarditis in 0% versus 9%, gastroduodenal ulceration and severe gastritis in 10 versus 21% and small bowel obstruction in 5 versus 8%. When using the linear quadratic model with an ..cap alpha../..beta.. of 2.5 Gy to evaluate the equivalent dose of 40 Gy given in 12 fractions of 3.3 Gy when delivered by fractions of 2.5 Gy, a value of 46.6 Gy is found. This difference of 6.6 Gy in the equivalent doses (for late toxicity) is likely to account for the significant increase of late radiation injuries, such as mediastinitis and pericarditis, in the present study. The local relapse rate was found to be slightly lower in the 3x3.3 Gy group. However, this possible benefit cannot offset the considerable increase of late complications.

  12. Fractionated stereotactic radiotherapy as a boost treatment for tumors in the head and neck region

    International Nuclear Information System (INIS)

    Uno, Takashi; Isobe, Kouichi; Ueno, Naoyuki; Ito, Hisao; Fukuda, Ataru; Sudo, Satoshi; Shirotori, Hiroaki; Kitahara, Isao; Fukushima, Takanori

    2010-01-01

    The objective of this retrospective study was to report initial results of CyberKnife stereotactic radiotherapy (SRT) boost for tumors in the head and neck area. Between March 2008 and August 2009, 10 patients were treated with SRT boost using CyberKnife system due mainly to unfavorable condition such as tumors in close proximity to serial organs or former radiotherapy fields. Treatment sites were the external auditory canal in two, the nasopharynx in one, the oropharynx in three, the nasal cavity in one, the maxillary sinus in two, and the oligometastatic cervical lymph node in one. All patients underwent preceding conventional radiotherapy of 40 to 60 Gy. Dose and fractionation scheme of the Cyberknife SRT boost was individualized, and prescribed dose ranged from 9 Gy to 16 Gy in 3 to 4 fractions. Among four patients for whom dose to the optic pathway was concerned, the maximum dose was only about 3 Gy for three patients whereas 9.6 Gy in the remaining one patient. The maximum dose for the mandible in one of three patients with oropharyngeal cancer was 19.7 Gy, whereas majority of the bone can be spared by using non-isocentric conformal beams. For a patient with nasopharyngeal cancer, the highest dose in the brain stem was 15 Gy. However, majority of the brain stem received less than 40% of the maximum dose. Although a small volume high dose area within the normal structure could be observed in several patients, results of the present study showed potential benefits of the CyberKnife SRT boost. (author)

  13. Analysis of hard coal quality for narrow size fraction under 20 mm

    Science.gov (United States)

    Niedoba, Tomasz; Pięta, Paulina

    2018-01-01

    The paper presents the results of an analysis of hard coal quality diversion in narrow size fraction by using taxonomic methods. Raw material samples were collected in selected mines of Upper Silesian Industrial Region and they were classified according to the Polish classification as types 31, 34.2 and 35. Then, each size fraction was characterized in terms of the following properties: density, ash content, calorific content, volatile content, total sulfur content and analytical moisture. As a result of the analysis it can be stated that the best quality in the entire range of the tested size fractions was the 34.2 coking coal type. At the same time, in terms of price parameters, high quality of raw material characterised the following size fractions: 0-6.3 mm of 31 energetic coal type and 0-3.15 mm of 35 coking coal type. The methods of grouping (Ward's method) and agglomeration (k-means method) have shown that the size fraction below 10 mm was characterized by higher quality in all the analyzed hard coal types. However, the selected taxonomic methods do not make it possible to identify individual size fraction or hard coal types based on chosen parameters.

  14. Optimization of the primary collimator settings for fractionated IMRT stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Tobler, Matt; Leavitt, Dennis D.; Watson, Gordon

    2004-01-01

    Advances in field-shaping techniques for stereotactic radiosurgery/radiotherapy have allowed dynamic adjustment of field shape with gantry rotation (dynamic conformal arc) in an effort to minimize dose to critical structures. Recent work evaluated the potential for increased sparing of dose to normal tissues when the primary collimator setting is optimized to only the size necessary to cover the largest shape of the dynamic micro multi leaf field. Intensity-modulated radiotherapy (IMRT) is now a treatment option for patients receiving stereotactic radiotherapy treatments. This multisegmentation of the dose delivered through multiple fixed treatment fields provides for delivery of uniform dose to the tumor volume while allowing sparing of critical structures, particularly for patients whose tumor volumes are less suited for rotational treatment. For these segmented fields, the total number of monitor units (MUs) delivered may be much greater than the number of MUs required if dose delivery occurred through an unmodulated treatment field. As a result, undesired dose delivered, as leakage through the leaves to tissues outside the area of interest, will be proportionally increased. This work will evaluate the role of optimization of the primary collimator setting for these IMRT treatment fields, and compare these results to treatment fields where the primary collimator settings have not been optimized

  15. Single Fraction Stereotactic Ablative Body Radiotherapy for Oligometastasis: Outcomes from 132 Consecutive Patients.

    Science.gov (United States)

    Gandhidasan, S; Ball, D; Kron, T; Bressel, M; Shaw, M; Chu, J; Chander, S; Wheeler, G; Plumridge, N; Chesson, B; David, S; Siva, S

    2018-03-01

    Stereotactic ablative body radiotherapy (SABR) is currently used to treat oligometastases, but the optimum dose/fractionation schedule is unknown. In this study, we evaluated outcomes after single fraction SABR in patients with oligometastatic disease. Single institutional retrospective review of patients treated with single fraction SABR for one to three oligometastases between 2010 and 2015. The primary outcome was freedom from widespread disease defined as distant recurrence not amenable to surgery or SABR; or recurrence with four or more metastases. In total, 186 treatments were delivered in 132 patients. The two most common target sites were lung (51%) and bone (40%). The most frequent single fraction prescription dose was 26 Gy (47%). The most common primary malignancy was genitourinary (n = 46 patients). Freedom from widespread disease was 75% at 1 year (95% confidence interval 67-83%) and 52% at 2 years (95% confidence interval 42-63%). Freedom from local progression at 1 year was 90% (95% confidence interval 85-95%) and at 2 years was 84% (95% confidence interval 77-91%). A compression fracture of the lumbar vertebra was the only grade 3+ treatment-related toxicity. Single fraction SABR is associated with a high rate of freedom from widespread disease, favourable local control and low toxicity comparable with historic multi-fraction SABR reports. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  16. Size fractionation and characterization of natural aquatic colloids and nanoparticles

    International Nuclear Information System (INIS)

    Baalousha, M.; Lead, J.R.

    2007-01-01

    Atomic force microscopy (AFM) was used to image and quantify natural nanoparticles (prefiltered < 25 nm) from three different freshwater sites (Vale Lake, Bailey Brook and Tern Rivers). Four fractions were analysed by AFM; the prefiltered fraction (< 25 nm) and three fractions collected after separation of this prefiltered sample by flow field-flow fractionation (FlFFF) which corresponds to material which has size ranges of < 4.2 nm, 4.2-15.8 nm and 15.8-32.4 nm, as determined by FlFFF theory. The large majority of materials in all samples appeared as < 3 nm nanoparticles, nearly spherical and rich in chromophores active at 254 nm UV, which thus correspond to natural organic matter. However, nanoparticles were also imaged up to slightly more than 25 nm in size, indicating a slight disagreement in sizing between filtration and FlFFF. In addition, some particles in certain fractions were found to be covered with a thin film of less than 0.5-1.0 nm. Substantial differences between sites were observed

  17. Stereotactic intracranial radiotherapy: Dose prescription

    International Nuclear Information System (INIS)

    Schlienger, M.; Lartigau, E.; Nataf, F.; Mornex, F.; Latorzeff, I.; Lisbona, A.; Mahe, M.

    2012-01-01

    The aim of this article was the study of the successive steps permitting the prescription of dose in stereotactic intracranial radiotherapy, which includes radiosurgery and fractionated stereotactic radiotherapy. The successive steps studied are: the choice of stereotactic intracranial radiotherapy among the therapeutic options, based on curative or palliative treatment intent, then the selection of lesions according to size/volume, pathological type and their number permitting the choice between radiosurgery or fractionated stereotactic radiotherapy, which have the same methodological basis. Clinical experience has determined the level of dose to treat the lesions and limit the irradiation of healthy adjacent tissues and organs at risk structures. The last step is the optimization of the different parameters to obtain a safe compromise between the lesion dose and healthy adjacent structures. Study of dose-volume histograms, coverage indices and 3D imaging permit the optimization of irradiation. For lesions close to or included in a critical area, the prescribed dose is planned using the inverse planing method. Implementation of the successively described steps is mandatory to insure the prescription of an optimized dose. The whole procedure is based on the delineation of the lesion and adjacent healthy tissues. There are sometimes difficulties to assess the delineation and the volume of the target, however improvement of local control rates and reduction of secondary effects are the proof that the totality of the successive procedures are progressively improved. In practice, stereotactic intracranial radiotherapy is a continually improved treatment method, which constantly benefits from improvements in the choice of indications, imaging, techniques of irradiation, planing/optimization methodology and irradiation technique and from data collected from prolonged follow-up. (authors)

  18. Radiotherapy Results of Early Uterine Cervix Cancer

    International Nuclear Information System (INIS)

    Choi, Doo Ho; Huh, Seung Jae

    1996-01-01

    Purpose : This study was done to analyze survivals, patterns of failure, and complications of early uterine cervix cancer after curative radiotherapy. Methods and Materials : Eighty patients with uterine cervix cancer FIGO Stage IB (48 cases) and Stage IIA (32 cases) treated with radiotherapy were analyzed retrospectively. Patients were treated from November 1985 to May 1993, and minimum follow up period was 24 months. and 6 cases were lost to follow up. All of them were treated with external radiotherapy and different fractions of high dose rate intracavitary radiotherapy. Survival rates, failure patterns, complication rates and degrees of severity were analyzed according to several factors. Results : Overall 5 year survival rate and relapse free survival rate were 72.3%, and 72.8% respectively. Prognostic factors were stage, size, pathology, RT response and there was no significant survival difference among the reasons of radiotherapy choice. There were 19 cases of treatment failure, another 3 cases were not tumor related death, and most of treatment related failure occurred within 24 months. Late complication rate of bladder and rectum were 8.8%, 15% respectively, frequency and severity of complication were correlated with ICR fractionation dose and total dose. Conclusion : These results showed that survival rates of early stage radiation treated cervix cancer patients were comparable to surgical series, but more aggressive treatment methods needed for stage IIA poor prognostic patients, To decrease late complication, choice of proper ICR dose and meticulous vaginal packing is needed

  19. Modelling size-fractionated primary production in the Atlantic Ocean from remote sensing

    Science.gov (United States)

    Brewin, Robert J. W.; Tilstone, Gavin H.; Jackson, Thomas; Cain, Terry; Miller, Peter I.; Lange, Priscila K.; Misra, Ankita; Airs, Ruth L.

    2017-11-01

    Marine primary production influences the transfer of carbon dioxide between the ocean and atmosphere, and the availability of energy for the pelagic food web. Both the rate and the fate of organic carbon from primary production are dependent on phytoplankton size. A key aim of the Atlantic Meridional Transect (AMT) programme has been to quantify biological carbon cycling in the Atlantic Ocean and measurements of total primary production have been routinely made on AMT cruises, as well as additional measurements of size-fractionated primary production on some cruises. Measurements of total primary production collected on the AMT have been used to evaluate remote-sensing techniques capable of producing basin-scale estimates of primary production. Though models exist to estimate size-fractionated primary production from satellite data, these have not been well validated in the Atlantic Ocean, and have been parameterised using measurements of phytoplankton pigments rather than direct measurements of phytoplankton size structure. Here, we re-tune a remote-sensing primary production model to estimate production in three size fractions of phytoplankton (10 μm) in the Atlantic Ocean, using measurements of size-fractionated chlorophyll and size-fractionated photosynthesis-irradiance experiments conducted on AMT 22 and 23 using sequential filtration-based methods. The performance of the remote-sensing technique was evaluated using: (i) independent estimates of size-fractionated primary production collected on a number of AMT cruises using 14C on-deck incubation experiments and (ii) Monte Carlo simulations. Considering uncertainty in the satellite inputs and model parameters, we estimate an average model error of between 0.27 and 0.63 for log10-transformed size-fractionated production, with lower errors for the small size class (10 μm), and errors generally higher in oligotrophic waters. Application to satellite data in 2007 suggests the contribution of cells 2 μm to total

  20. Low or High Fractionation Dose {beta}-Radiotherapy for Pterygium? A Randomized Clinical Trial

    Energy Technology Data Exchange (ETDEWEB)

    Viani, Gustavo Arruda, E-mail: gusviani@gmail.com [Department of Radiation Oncology, Marilia Medicine School, Sao Paulo, SP (Brazil); De Fendi, Ligia Issa; Fonseca, Ellen Carrara [Department of Ophthalmology, Marilia Medicine School, Sao Paulo, SP (Brazil); Stefano, Eduardo Jose [Department of Radiation Oncology, Marilia Medicine School, Sao Paulo, SP (Brazil)

    2012-02-01

    Purpose: Postoperative adjuvant treatment using {beta}-radiotherapy (RT) is a proven technique for reducing the recurrence of pterygium. A randomized trial was conducted to determine whether a low fractionation dose of 2 Gy within 10 fractions would provide local control similar to that after a high fractionation dose of 5 Gy within 7 fractions for surgically resected pterygium. Methods: A randomized trial was conducted in 200 patients (216 pterygia) between February 2006 and July 2007. Only patients with fresh pterygium resected using a bare sclera method and given RT within 3 days were included. Postoperative RT was delivered using a strontium-90 eye applicator. The pterygia were randomly treated using either 5 Gy within 7 fractions (Group 1) or 2 Gy within 10 fractions (Group 2). The local control rate was calculated from the date of surgery. Results: Of the 216 pterygia included, 112 were allocated to Group 1 and 104 to Group 2. The 3-year local control rate for Groups 1 and 2 was 93.8% and 92.3%, respectively (p = .616). A statistically significant difference for cosmetic effect (p = .034), photophobia (p = .02), irritation (p = .001), and scleromalacia (p = .017) was noted in favor of Group 2. Conclusions: No better local control rate for postoperative pterygium was obtained using high-dose fractionation vs. low-dose fractionation. However, a low-dose fractionation schedule produced better cosmetic effects and resulted in fewer symptoms than high-dose fractionation. Moreover, pterygia can be safely treated in terms of local recurrence using RT schedules with a biologic effective dose of 24-52.5 Gy{sub 10.}.

  1. High-dose rate fractionated interstitial radiotherapy for oropharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Nose, Takayuki; Inoue, Toshihiko; Inoue, Takehiro; Teshima, Teruki; Murayama, Shigeyuki [Osaka Univ. (Japan). Faculty of Medicine

    1995-03-01

    The limitations of treating oropharyngeal cancer patients with definitive external radiotherapy are the complications of salivary glands, taste buds, mandible and temporomandibular joints. To avoid these complications we started interstitial radiotherapy as boost after 46 Gy of external radiotherapy. Ten cases (retromolar trigone; 1, soft palate; 1, base of tongue; 3, lateral wall; 5) were treated with this method and seven cases were controlled locally. With short follow-up period, xerostomia and dysgeusia are less than definitive external radiotherapy as clinical impression and no in-field recurrences have been experienced. With markedly increased tumor dose, the local control rate can be improved. This treatment method will be an alternative to definitive external radiotherapy to gain better QOL and higher control rate. (author).

  2. Palonosetron and prednisolone for the prevention of nausea and emesis during fractionated radiotherapy and 5 cycles of concomitant weekly cisplatin-a phase II study

    DEFF Research Database (Denmark)

    Ruhlmann, Christina H; Belli, Charlotte; Dahl, Tina

    2013-01-01

    Recommendations for antiemetic prophylaxis supportive to radiotherapy and concomitant chemotherapy are not evidence-based. The purpose of this study was to evaluate the efficacy of the antiemetic regimen concurrent to fractionated radiotherapy and concomitant weekly cisplatin in two Danish depart...

  3. Radiotherapy - an effective treatment for vaginal verrucous carcinoma

    International Nuclear Information System (INIS)

    Reinecke, L.; Thornley, A.L.

    1993-01-01

    Vaginal carcinoma makes up 1%-2% of all gynaecological tumours. Verrucous carcinoma of the vagina is even more rare -only 16 cases are reported in the scientific literature. A case of a complete regression after 60 Gy fractionated radiotherapy by a tumour 12 cm 3 in size is reported. Most authors are of the opinion that radiotherapy causes anaplastic transformation of verrucous carcinoma. The minority view, that anaplastic transformation does not occur, is correct and is supported by our clinical and radiological data. The conflicting literature on vaginal verrucous carcinoma (VVC) is reviewed with reference to verrucous carcinoma at other sites. (Author)

  4. Treatment of pituitary adenomas by fractionated stereotactic radiotherapy: A prospective study of 110 patients

    International Nuclear Information System (INIS)

    Colin, Philippe; Jovenin, Nicolas; Delemer, Brigitte; Caron, Jean; Grulet, Herve; Hecart, Annie-Claude; Lukas, Celine; Bazin, Arnaud; Bernard, Mary-Helene; Scherpereel, Bernard; Peruzzi, Philippe; Nakib, Iab; Redon, Charles; Rousseaux, Pascal

    2005-01-01

    Purpose: To optimize and reduce the toxicity of pituitary adenoma irradiation by assessing the feasibility and effectiveness of fractionated stereotactic radiotherapy (FSR). Methods and Materials: Between 1990 and 1999, 110 consecutive patients, 47 with a functioning adenoma, were treated according to a strategy of either early surgery and FSR (n = 89) or FSR only (n = 21). Of the 110 patients, 75 had persistent macroscopic tumor and 47 persistent hormonal secretions; 15 were treated in the prophylactic setting. The linear accelerator-delivered dose was 50.4 Gy (5 x 1.8 Gy weekly), with a 2-mm safety margin. Results: After a minimal follow-up of 48 months, only 1 patient had developed progression. Of the 110 patients, 27 (36%) had a complete tumor response, 67 (89.3%) had an objective tumor response, 20 (42%) had a hormonal complete response, and 47 (100%) had a hormonal objective tumor response. The proportion of patients without a complete tumor response, objective tumor response, complete hormonal response, and objective hormonal response was 85.1%, 62%, 83%, and 59.3% at 4 years and 49.3%, 9%, 59.3%, and 10.6% at 8 years, respectively. The sole unfavorable predictive factor was preoperative SSE >20 mm for tumor response (p = 0.01) and growth hormone adenoma for the hormonal response (p <0.001). No late complications, except for pituitary deficiency, were reported, with a probability of requiring hormonal replacement of 28.5% and 35% at 4 and 8 years, respectively. Nonfunctioning status was the sole unfavorable factor (p = 0.0016). Conclusions: Surgery plus FSR is safe and effective. FSR focused to the target volume seems more suitable than standard radiotherapy, and standard fractionation reduces the risk of optic neuropathy sometimes observed after single-dose radiosurgery. Therefore, FSR allows us to consider combined transrhinoseptal surgery and early radiotherapy, with a curative goal without patient selection

  5. Size fractionation of waste-to-energy boiler ash enables separation of a coarse fraction with low dioxin concentrations

    DEFF Research Database (Denmark)

    Weidemann, E.; Allegrini, Elisa; Astrup, Thomas Fruergaard

    2016-01-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) formed in modern Waste-to-Energy plants are primarily found in the generated ashes and air pollution control residues, which are usually disposed of as hazardous waste. The objective of this study was to explore the occurrence of PCDD....../F in different grain size fractions in the boiler ash, i.e. ash originating from the convection pass of the boiler. If a correlation between particle size and dioxin concentrations could be found, size fractionation of the ashes could reduce the total amount of hazardous waste. Boiler ash samples from ten...... sections of a boiler's convective part were collected over three sampling days, sieved into three different size fractions - 0.355. mm - and analysed for PCDD/F. The coarse fraction (>0.355. mm) in the first sections of the horizontal convection pass appeared to be of low toxicity with respect to dioxin...

  6. Metagenomic analysis of size-fractionated picoplankton in a marine oxygen minimum zone.

    Science.gov (United States)

    Ganesh, Sangita; Parris, Darren J; DeLong, Edward F; Stewart, Frank J

    2014-01-01

    Marine oxygen minimum zones (OMZs) support diverse microbial communities with roles in major elemental cycles. It is unclear how the taxonomic composition and metabolism of OMZ microorganisms vary between particle-associated and free-living size fractions. We used amplicon (16S rRNA gene) and shotgun metagenome sequencing to compare microbial communities from large (>1.6 μm) and small (0.2-1.6 μm) filter size fractions along a depth gradient in the OMZ off Chile. Despite steep vertical redox gradients, size fraction was a significantly stronger predictor of community composition compared to depth. Phylogenetic diversity showed contrasting patterns, decreasing towards the anoxic OMZ core in the small size fraction, but exhibiting maximal values at these depths within the larger size fraction. Fraction-specific distributions were evident for key OMZ taxa, including anammox planctomycetes, whose coding sequences were enriched up to threefold in the 0.2-1.6 μm community. Functional gene composition also differed between fractions, with the >1.6 μm community significantly enriched in genes mediating social interactions, including motility, adhesion, cell-to-cell transfer, antibiotic resistance and mobile element activity. Prokaryotic transposase genes were three to six fold more abundant in this fraction, comprising up to 2% of protein-coding sequences, suggesting that particle surfaces may act as hotbeds for transposition-based genome changes in marine microbes. Genes for nitric and nitrous oxide reduction were also more abundant (three to seven fold) in the larger size fraction, suggesting microniche partitioning of key denitrification steps. These results highlight an important role for surface attachment in shaping community metabolic potential and genome content in OMZ microorganisms.

  7. Fractionated stereotactic radiotherapy for vestibular schwannoma (VS): Comparison between cystic-type and solid-type VS

    International Nuclear Information System (INIS)

    Shirato, Hiroki; Sakamoto, Touru; Takeichi, Norihito; Aoyama, Hidefumi; Suzuki, Keishiro; Kagei, Kenji; Nishioka, Takashi; Fukuda, Satoshi; Sawamura, Yutaka; Miyasaka, Kazuo

    2000-01-01

    Purpose: To compare the effectiveness and complications of fractionated stereotactic radiotherapy (SRT) for cystic-type vestibular schwannoma (VS) with those of solid-type VS. Methods and Materials: In 65 patients treated with fractionated SRT between 1991 and 1999, 20 were diagnosed with cystic VS, in which at least one-third of the tumor volume was a cystic component on magnetic resonance imaging (MRI), and 45 were diagnosed with solid VS. Thirty-six Gy to 50 Gy in 20-25 fractions was administered to the isocenter and approximately 80% of the periphery of the tumor. All cystic and solid components were included in the gross tumor volume. The mean follow-up period was 37 months, ranging from 6 to 97 months. Results: The actuarial 3-year rate of no episode of enlargement greater than 2.0 mm was 55% for cystic-type and 75% for solid-type VS; the difference was statistically significant (p 0.023). The actuarial 3-year tumor-reduction (reduction in tumor size greater than 2.0 mm) rates were 93% and 31%, respectively (p = 0.0006). The overall actuarial tumor control rate (no tumor growth greater than 2.0 mm after 2 years or no requirement of salvage surgery) was 92% at 5 years in 44 patients with a follow-up period of 2 or more years. There was no difference in the class hearing preservation rate between cystic VS and solid VS. No permanent trigeminal or facial nerve palsy was observed in either group. Conclusion: Transient tumor enlargement occurs in cystic VS more frequently than in solid-type VS, but the subsequent tumor-reduction rate in cystic VS is better.

  8. Nausea and vomiting in fractionated radiotherapy: a prospective on-demand trial of tropisetron rescue for non-responders to metoclopramide

    International Nuclear Information System (INIS)

    Miralbell, R.; Behrouz, F.; Coucke, P.

    1995-01-01

    A prospective trial was performed to better assess the risk of nausea and vomiting and the rescue value of tropisetron (TRO), a 5-HT 3 receptor antagonist, in 88 patients undergoing fractionated radiotherapy to the abdomen or to large supradiaphragmatic fields and failing a first anti-emetic trial with metoclopramide (MET). Nausea was graded 0 (absent), 1 (mild), 2 (moderate) and 3 (severe). Nausea requiring anti-emetics (≥ grade 2) was present in 64% of the patients. MET was able to control nausea (≤ grade 1) in 26 of 58 patients (45%) who developed ≥ grade 2 nausea during radiation treatment (2 patients vomiting without nausea included). 34 patients required TRO, and 31 experienced immediate relief. However, nausea (≥ grade 2) recurred in 7 patients from 1 to 3 weeks after starting TRO. Sex, age, field type and field size (cm 2 ) did not influence the incidence and severity of nausea and vomiting. Only 24/88 patients vomited after starting radiotherapy. MET helped to eliminate emesis in one third of these patients. TRO helped to control vomiting in 73% of the salvaged patients. Constipation was observed in 8 patients on TRO and was a reason to stop the medication in 4 cases. (author)

  9. Four R's of radiotherapy

    International Nuclear Information System (INIS)

    Withers, H.R.

    1975-01-01

    Radiotherapy given as multiple doses can be effective in sterilizing cancers, but the processes whereby the neoplasm is eradicated and the normal tissues are preserved are not fully understood. The differential between normal tissue and tumor response is enhanced by dose fractionation, single doses resulting in severe normal tissue injury when the dose is sufficient to control a proportion of treated tumors. Data are reviewed from radiobiological studies on laboratory animals and cultured cells that have thrown some light on four of the phenomena that influence the outcome of fractionated-dose radiotherapy, one or more of which may account for the relative sparing of normal tissues. These are repair of sublethal injury in normal and neoplastic cells, reoxygenation of the tumor, redistribution through the division cycle, and regeneration of surviving normal and malignant cells between dose fractions. These have been called the four R's of fractionated radiotherapy. Other factors are involved in the outcome of multifraction radiotherapy, including maintenance of the architectural integrity of the normal tissues, the volume of tissue irradi []ted, the tumor bed, and the immunocompetence of the host. (90 references) (CH)

  10. Treatment fractionation for stereotactic radiotherapy of lung tumours: a modelling study of the influence of chronic and acute hypoxia on tumour control probability

    International Nuclear Information System (INIS)

    Lindblom, Emely; Antonovic, Laura; Dasu, Alexandru; Lax, Ingmar; Wersäll, Peter; Toma-Dasu, Iuliana

    2014-01-01

    Stereotactic body radiotherapy (SBRT) for non-small-cell lung cancer (NSCLC) has led to promising local control and overall survival for fractionation schemes with increasingly high fractional doses. A point has however been reached where the number of fractions used might be too low to allow efficient local inter-fraction reoxygenation of the hypoxic cells residing in the tumour. It was therefore the purpose of this study to investigate the impact of hypoxia and extreme hypofractionation on the tumour control probability (TCP) from SBRT. A three-dimensional model of tumour oxygenation able to simulate oxygenation changes on the microscale was used. The TCP was determined for clinically relevant SBRT fractionation schedules of 1, 3 and 5 fractions assuming either static tumour oxygenation or that the oxygenation changes locally between fractions due to fast reoxygenation of acute hypoxia without an overall reduction in chronic hypoxia. For the schedules applying three or five fractions the doses required to achieve satisfying levels of TCP were considerably lower when local oxygenation changes were assumed compared to the case of static oxygenation; a decrease in D 50 of 17.7 Gy was observed for a five-fractions schedule applied to a 20% hypoxic tumour when fast reoxygenation was modelled. Assuming local oxygenation changes, the total doses required for a tumor control probability of 50% were of similar size for one, three and five fractions. Although attractive from a practical point of view, extreme hypofractionation using just one single fraction may result in impaired local control of hypoxic tumours, as it eliminates the possibility for any kind of reoxygenation

  11. Dose rate effect from the relationship between ICRU rectal dose and local control rate in intracavitary radiotherapy for carcinoma of the uterine cervix. Six fraction HDR and three-fraction LDR in three weeks

    International Nuclear Information System (INIS)

    Jingu, Kenichi; Akita, Yuzou; Ohmagari, Jyunichi

    2001-01-01

    The dose rate effect, low dose rate radiotherapy (LDR)/high dose rate radiotherapy (HDR), was calculated using the isoeffect ICRU rectal dose by intracavitary radiotherapy (ICRT) for uterine cervix cancer. The subjects analyzed consisted of 78 LDR and 74 HDR patients whose ICRU rectal dose could be calculated and whose local control as stage II/III cases could be evaluated. The point A dose in ICRT was 45-55 Gy/3 fractions/3 weeks for LDR and 30 Gy/6 fractions/3 weeks for HDR. The dose effect relationships associated with local control at each whole pelvis external radiation dose were calculated using the double integration method and Probit analysis, and the 50% and 90% local control ICRU rectal doses were calculated from this relationship. Finally, the dose rate effect LDR/HDR was determined from 50% and 90% local control doses. The dose rate effect calculated from the 50% local control dose was 1.24 and that from the 90% local control dose was 1.14. (author)

  12. Preliminary Results of Fractionated Stereotactic Radiotherapy After Cyst Drainage for Craniopharyngioma in Adults

    International Nuclear Information System (INIS)

    Kanesaka, Naoto; Mikami, Ryuji; Nakayama, Hidetsugu; Nogi, Sachika; Tajima, Yu; Nakajima, Nobuyuki; Wada, Jun; Miki, Tamotsu; Haraoka, Jou; Okubo, Mitsuru; Sugahara, Shinji; Tokuuye, Koichi

    2012-01-01

    Purpose: To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for craniopharyngioma. Methods and Materials: Between 1999 and 2005, 16 patients with craniopharyngioma were referred to Tokyo Medical University Hospital. They received FSRT alone after histologic confirmation by needle biopsy and underwent cyst drainage via endoscopy. The median prescription dose fraction was 30 Gy in six fractions. All patients except 1 were followed up until December 2009 or death. Results: The median follow-up period was 52 months (range, 4–117 months). Of the 17 patients, 3 experienced recurrence 4 to 71 months after FSRT. The 3-year local control rate was 82.4%. One patient died of thyroid cancer, and the 3-year survival rate was 94.1%. Eight patients had improved visual fields at a median of 2.5 months after FSRT, but hormonal functions did not improve in any patient. Conclusions: FSRT after cyst drainage seems to be safe and effective for patients with craniopharyngiomas, and it may be a safe alternative to surgery.

  13. Preliminary Results of Fractionated Stereotactic Radiotherapy After Cyst Drainage for Craniopharyngioma in Adults

    Energy Technology Data Exchange (ETDEWEB)

    Kanesaka, Naoto, E-mail: kaneka@tokyo-med.ac.jp [Department of Radiology, Tokyo Medical University Hospital, Tokyo (Japan); Mikami, Ryuji; Nakayama, Hidetsugu; Nogi, Sachika; Tajima, Yu [Department of Radiology, Tokyo Medical University Hospital, Tokyo (Japan); Nakajima, Nobuyuki; Wada, Jun; Miki, Tamotsu; Haraoka, Jou [Department of Neurosurgery, Tokyo Medical University Hospital, Tokyo (Japan); Okubo, Mitsuru [Department of Radiology, Tokyo Medical University Hachioji Medical Center, Tokyo (Japan); Sugahara, Shinji [Department of Radiology, Tokyo Medical University Ibaraki Medical Center, Tokyo (Japan); Tokuuye, Koichi [Department of Radiology, Tokyo Medical University Hospital, Tokyo (Japan)

    2012-03-15

    Purpose: To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for craniopharyngioma. Methods and Materials: Between 1999 and 2005, 16 patients with craniopharyngioma were referred to Tokyo Medical University Hospital. They received FSRT alone after histologic confirmation by needle biopsy and underwent cyst drainage via endoscopy. The median prescription dose fraction was 30 Gy in six fractions. All patients except 1 were followed up until December 2009 or death. Results: The median follow-up period was 52 months (range, 4-117 months). Of the 17 patients, 3 experienced recurrence 4 to 71 months after FSRT. The 3-year local control rate was 82.4%. One patient died of thyroid cancer, and the 3-year survival rate was 94.1%. Eight patients had improved visual fields at a median of 2.5 months after FSRT, but hormonal functions did not improve in any patient. Conclusions: FSRT after cyst drainage seems to be safe and effective for patients with craniopharyngiomas, and it may be a safe alternative to surgery.

  14. Chest wall desmoid tumours treated with definitive radiotherapy: a plan comparison of 3D conformal radiotherapy, intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy

    International Nuclear Information System (INIS)

    Liu, Jia; Ng, Diana; Lee, James; Stalley, Paul; Hong, Angela

    2016-01-01

    Definitive radiotherapy is often used for chest wall desmoid tumours due to size or anatomical location. The delivery of radiotherapy is challenging due to the large size and constraints of normal surrounding structures. We compared the dosimetry of 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) to evaluate the best treatment option. Ten consecutive patients with inoperable chest wall desmoid tumours (PTV range 416–4549 cm 3 ) were selected. For each patient, 3DCRT, IMRT and VMAT plans were generated and the Conformity Index (CI), organ at risk (OAR) doses and monitor unit (MU) were evaluated. The Wilcoxon signed-rank test was used to compare dose delivered to both target and OARs. The mean number of fields for 3DCRT and IMRT were 6.3 ± 2.1, 7.2 ± 1.8. The mean number of arcs for VMAT was 3.7 ± 1.1. The mean conformity index of VMAT (0.98 ± 0.14) was similar to that of IMRT (1.03 ± 0.13), both of which were significantly better than 3DCRT (1.35 ± 0.20; p = 0.005). The mean dose to lung was significantly higher for 3DCRT (11.9Gy ± 7.9) compared to IMRT (9.4Gy ± 5.4, p = 0.014) and VMAT (8.9Gy ± 4.5, p = 0.017). For the 3 females, the low dose regions in the ipsilateral breast for VMAT were generally less with VMAT. IMRT plans required 1427 ± 532 MU per fraction which was almost 4-fold higher than 3DCRT (313 ± 112, P = 0.005). Compared to IMRT, VMAT plans required 60 % less MU (570 ± 285, P = 0.005). For inoperable chest wall desmoid tumours, VMAT delivered equivalent target coverage when compared to IMRT but required 60 % less MU. Both VMAT and IMRT were superior to 3DCRT in terms of better PTV coverage and sparing of lung tissue

  15. Intra-fraction prostate displacement in radiotherapy estimated from pre- and post-treatment imaging of patients with implanted fiducial markers

    International Nuclear Information System (INIS)

    Kron, Tomas; Thomas, Jessica; Fox, Chris; Thompson, Ann; Owen, Rebecca; Herschtal, Alan; Haworth, Annette; Tai, Keen-Hun; Foroudi, Farshad

    2010-01-01

    Purpose: To determine intra-fraction displacement of the prostate gland from imaging pre- and post-radiotherapy delivery of prostate cancer patients with three implanted fiducial markers. Methods and materials: Data were collected from 184 patients who had two orthogonal X-rays pre- and post-delivery on at least 20 occasions using a Varian On Board kV Imaging system. A total of 5778 image pairs covering time intervals between 3 and 30 min between pre- and post-imaging were evaluated for intra-fraction prostate displacement. Results: The mean three dimensional vector shift between images was 1.7 mm ranging from 0 to 25 mm. No preferential direction of displacement was found; however, there was an increase of prostate displacement with time between images. There was a large variation in typical shifts between patients (range 1 ± 1 to 6 ± 2 mm) with no apparent trends throughout the treatment course. Images acquired in the first five fractions of treatment could be used to predict displacement patterns for individual patients. Conclusion: Intra-fraction motion of the prostate gland appears to be a limiting factor when considering margins for radiotherapy. Given the variation between patients, a uniform set of margins for all patients may not be satisfactory when high target doses are to be delivered.

  16. Treating all fields in every radiotherapy session? - Questioning the old dogma (or, pelvis radiotherapy: speculations on fractioning)

    International Nuclear Information System (INIS)

    Faria, S.L.; Ferrigno, R.; Osti, N.

    1995-01-01

    Twenty years ago Wilson and Hall published paper on the advisability of treating all fields at each radiotherapy session. That was based on the widely accepted method for calculating the biological effect of fractionated treatment in terms of a single quantity: the concept of a nominal standard dose (NSD). It was the beginning of an old dogma in radiation oncology: treating all fields every day. The basis megavoltage units of treatment in Brazil are cobalt and low energy linacs. The country is poor and it is not rare to have patients waiting lines. Due to that situation since five years ago we have been treating pelvic tumors with four fields (box technique) but irradiating only two fields per day. After treating hundreds of patients this way we have found no increased late complications, particularly subcutaneous tissue fibrosis. Previous data showed that TDE factors equal or lower than 90 were not related to any kind of fibrosis. treating pelvic tumors with the box technique but irradiating only two fields per day gives TDF values little greater than doing all four fields per day, but still lower than 90. That may explain why we have found no fibrosis. The impression is that not to treat all fields at each radiotherapy session may be possible with no increased rate of late complications. (author). 10 refs, 3 tabs, 2 figs

  17. Apoptotic potential and cell sensitivity to fractionated radiotherapy

    International Nuclear Information System (INIS)

    Rupnow, Brent A.; Murtha, Albert D.; Alarcon, Rodolfo M.; Giaccia, Amato J.; Knox, Susan J.

    1997-01-01

    irradiation resulted in decreased clonogenic survival of Rat-1MycER cells compared to cells treated without c-MycER activation following single doses of radiation from 0 to 10 Gy. The increased radiosensitivity conferred by c-Myc activation was suppressed by Bcl-2 overexpression, suggesting that c-Myc-mediated alterations in clonogenic survival are a result of altered apoptotic potential. While the difference in survival was only 1.22-fold following a single 2 Gy dose between Rat-1MycER cells treated in the presence and absence of c-MycER activation, treatment with 5 fractions of 2 Gy at 12 hour intervals resulted in a 2.99-fold decrease in clonogenic survival. Treatment of cells with 5 fractions of 4 Gy resulted in a 16.4-fold difference in clonogenic survival between cells with activated c-MycER and identical cells with inactive c-MycER, while the difference in survival was only 1.60-fold following a single 4 Gy dose. Bcl-2 overexpression was able to suppress c-Myc-mediated alterations in clonogenic survival following treatment with fractionated radiation. Conclusions: These results argue that increasing the sensitivity of cells to radiation-induced apoptosis can decrease their clonogenic survival in vitro. Furthermore, even small apoptosis-dependent differences in survival following single, small fractions of radiation may result in substantial differences in survival following multiple fractions of radiation. Experiments using Rat-1MycER derived tumor xenografts to test the effects of c-Myc-mediated alterations in apoptotic sensitivity on tumor growth delay following single dose and fractionated radiotherapy, in vivo, are in progress and will be discussed

  18. Intra-fractional uncertainties in image-guided intensity-modulated radiotherapy (IMRT) of prostate cancer

    International Nuclear Information System (INIS)

    Polat, Buelent; Guenther, Iris; Wilbert, Juergen; Goebel, Joachim; Sweeney, Reinhart A.; Flentje, Michael; Guckenberger, Matthias

    2008-01-01

    To evaluate intra-fractional uncertainties during intensity-modulated radiotherapy (IMRT) of prostate cancer. During IMRT of 21 consecutive patients, kilovolt (kV) cone-beam computed tomography (CBCT) images were acquired prior to and immediately after treatment: a total of 252 treatment fractions with 504 CBCT studies were basis of this analysis. The prostate position in anterior-posterior (AP) direction was determined using contour matching; patient set-up based on the pelvic bony anatomy was evaluated using automatic image registration. Internal variability of the prostate position was the difference between absolute prostate and patient position errors. Intra-fractional changes of prostate position, patient position, rectal distension in AP direction and bladder volume were analyzed. With a median treatment time of 16 min, intra-fractional drifts of the prostate were > 5 mm in 12% of all fractions and a margin of 6 mm was calculated for compensation of this uncertainty. Mobility of the prostate was independent from the bony anatomy with poor correlation between absolute prostate motion and motion of the bony anatomy (R 2 = 0.24). A systematic increase of bladder filling by 41 ccm on average was observed; however, these changes did not influence the prostate position. Small variations of the prostate position occurred independently from intra-fractional changes of the rectal distension; a weak correlation between large internal prostate motion and changes of the rectal volume was observed (R 2 = 0.55). Clinically significant intra-fractional changes of the prostate position were observed and margins of 6 mm were calculated for this intra-fractional uncertainty. Repeated or continuous verification of the prostate position may allow further margin reduction. (orig.)

  19. Intra-fractional uncertainties in image-guided intensity-modulated radiotherapy (IMRT) of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Polat, Buelent; Guenther, Iris; Wilbert, Juergen; Goebel, Joachim; Sweeney, Reinhart A.; Flentje, Michael; Guckenberger, Matthias [Wuerzburg Univ. (Germany). Dept. of Radiation Oncology

    2008-12-15

    To evaluate intra-fractional uncertainties during intensity-modulated radiotherapy (IMRT) of prostate cancer. During IMRT of 21 consecutive patients, kilovolt (kV) cone-beam computed tomography (CBCT) images were acquired prior to and immediately after treatment: a total of 252 treatment fractions with 504 CBCT studies were basis of this analysis. The prostate position in anterior-posterior (AP) direction was determined using contour matching; patient set-up based on the pelvic bony anatomy was evaluated using automatic image registration. Internal variability of the prostate position was the difference between absolute prostate and patient position errors. Intra-fractional changes of prostate position, patient position, rectal distension in AP direction and bladder volume were analyzed. With a median treatment time of 16 min, intra-fractional drifts of the prostate were > 5 mm in 12% of all fractions and a margin of 6 mm was calculated for compensation of this uncertainty. Mobility of the prostate was independent from the bony anatomy with poor correlation between absolute prostate motion and motion of the bony anatomy (R{sup 2} = 0.24). A systematic increase of bladder filling by 41 ccm on average was observed; however, these changes did not influence the prostate position. Small variations of the prostate position occurred independently from intra-fractional changes of the rectal distension; a weak correlation between large internal prostate motion and changes of the rectal volume was observed (R{sup 2} = 0.55). Clinically significant intra-fractional changes of the prostate position were observed and margins of 6 mm were calculated for this intra-fractional uncertainty. Repeated or continuous verification of the prostate position may allow further margin reduction. (orig.)

  20. Relationship of bone marrow dose to eosinophilia following radiotherapy

    International Nuclear Information System (INIS)

    Murohashi, Ikuo; Gomi, Hiromichi; Nakano, Takashi; Morita, Shinroku; Arai, Tatsuo; Jinnai, Itsuro; Nara, Nobuo; Bessho, Masami; Hirashima, Kunitake.

    1986-01-01

    Absolute blood eosinophils were counted prior to and during radiotherapy in a total of 380 patients with carcinoma in the chest, pelvis, or abdomen. The patients were divided into 5 groups by types of cancer, and these groups differed in the irradiation sites or the sizes of radiation field. Accumulated bone marrow dose from the start of radiotherapy to the time when eosinophil count during radiotherapy reached its peak was simultaneously determined. In each group, maximum eosinophil count during radiotherapy was significantly increased compared with the value before radiotherapy. In all groups except one, the increase in eosinophil count following radiotherapy was directly proportional to the bone marrow dose. However, in the most heavily irradiated ovarian cancer group, the increase in eosinophil count was markedly lower. In contrast, neutrophils were reduced in numbers in all groups. These results suggest that bone marrow (red marrow) damage by irradiation results in eosinophilia, and that unimpaired hemopoiesis is also indispensable for such an eosinophil response. Accumulated bone marrow doses of 800 - 900 rad given during 4 weeks fractionated irradiation caused the most prominent eosinophilia. (author)

  1. Stereotactic radiotherapy of the prostate: fractionation and utilization in the United States

    International Nuclear Information System (INIS)

    Weiner, Josph P.; Schwartz, David; Shao, Meng; Osborn, Virginia; Schreiber, David; Choi, Kwang

    2017-01-01

    To analyze the utilization and fractionation of extreme hypofractionation via stereotactic body radiotherapy (SBRT) in the treatment of prostate cancer. Data was analyzed on men diagnosed with localized prostate cancer between 2004–2012 and treated with definitive-intent radiation therapy, as captured in the National Cancer Database. This database is a hospital-based registry that collects an estimated 70% of all diagnosed malignancies in the United States. There were 299,186 patients identified, of which 4,962 (1.7%) were identified as receiving SBRT as primary treatment. Of those men, 2,082 had low risk disease (42.0%), 2,201 had intermediate risk disease (44.4%), and 679 had high risk disease (13.7%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012. Initially SBRT was more commonly used in academic programs, though as time progressed there was a shift to favor an increased absolute number of men treated in the community setting. Delivery of five separate treatments was the most commonly utilized fractionation pattern, with 4,635 patients (91.3%) receiving this number of treatments. The most common dosing pattern was 725 cGy × 5 fractions (49.6%) followed by 700 cGy × 5 fractions (21.3%). Extreme hypofractionation via SBRT is slowly increasing acceptance. Currently 700-725 cGy × 5 fractions appears to be the most commonly employed scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of this modality is expected to continue to increase

  2. Stereotactic radiotherapy of the prostate: fractionation and utilization in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Weiner, Josph P.; Schwartz, David; Shao, Meng; Osborn, Virginia; Schreiber, David [Dept. of Radiation Oncology, Veterans Affairs New York Harbor Healthcare System, Brooklyn (United States); Choi, Kwang [Dept. of Radiation Oncology, SUNY Downstate Medical Center, Brooklyn (United States)

    2017-06-15

    To analyze the utilization and fractionation of extreme hypofractionation via stereotactic body radiotherapy (SBRT) in the treatment of prostate cancer. Data was analyzed on men diagnosed with localized prostate cancer between 2004–2012 and treated with definitive-intent radiation therapy, as captured in the National Cancer Database. This database is a hospital-based registry that collects an estimated 70% of all diagnosed malignancies in the United States. There were 299,186 patients identified, of which 4,962 (1.7%) were identified as receiving SBRT as primary treatment. Of those men, 2,082 had low risk disease (42.0%), 2,201 had intermediate risk disease (44.4%), and 679 had high risk disease (13.7%). The relative utilization of SBRT increased from 0.1% in 2004 to 4.0% in 2012. Initially SBRT was more commonly used in academic programs, though as time progressed there was a shift to favor an increased absolute number of men treated in the community setting. Delivery of five separate treatments was the most commonly utilized fractionation pattern, with 4,635 patients (91.3%) receiving this number of treatments. The most common dosing pattern was 725 cGy × 5 fractions (49.6%) followed by 700 cGy × 5 fractions (21.3%). Extreme hypofractionation via SBRT is slowly increasing acceptance. Currently 700-725 cGy × 5 fractions appears to be the most commonly employed scheme. As further long-term data regarding the safety and efficacy emerges, the relative utilization of this modality is expected to continue to increase.

  3. Cyberknife fractionated radiotherapy for adrenal metastases: Preliminary report from a multispecialty Indian cancer care center

    Directory of Open Access Journals (Sweden)

    Trinanjan Basu

    2015-03-01

    Full Text Available Purpose: Metastasis to adrenal gland from lung, breast, and kidney malignancies are quite common. Historically radiotherapy was intended for pain palliation. Recent studies with stereotactic body radiotherapy (SBRT including Cyberknife robotic radiosurgery aiming at disease control brings about encouraging results. Here we represent the early clinical experience with Cyberknife stereotactic system from an Indian cancer care center. The main purpose of this retrospective review is to serve as a stepping stone for future prospective studies with non- invasive yet effective technique compared to surgery. Methods: We retrospectively reviewed four cases of adrenal metastases (three: lung and one: renal cell carcinoma treated with Cyberknife SBRT. X sight spine tracking was employed for planning and treatment delivery. Patients were evaluated for local response clinically as well as with PETCT based response criteria.Results: With a median gross tumor volume of 20.5 cc and median dose per fraction of 10 Gy, two patients had complete response (CR and two had partial response (PR when assessed 8-12 weeks post treatment as per RECIST. There was no RTOG grade 2 or more acute adverse events and organs at risk dosage were acceptable. Till last follow up all the patients were locally controlled and alive. Conclusion: Cyberknife SBRT with its unique advantages like non- invasive, short duration outpatient treatment technique culminating in similar local control rates in comparison to surgery is an attractive option. World literature of linear accelerator based SBRT and our data with Cyberknife SBRT with small sample size and early follow up are similar in terms of local control in adrenal metastases. Future prospective data would reveal more information on the management of adrenal metastases.

  4. Five compared with six fractions per week of conventional radiotherapy of squamous-cell carcinoma of head and neck: DAHANCA 6 and 7 randomised controlled trial

    DEFF Research Database (Denmark)

    Overgaard, Jens; Hansen, Hanne Sand; Specht, Lena

    2003-01-01

    Although head and neck cancer can be cured by radiotherapy, the optimum treatment time for locoregional control is unclear. We aimed to find out whether shortening of treatment time by use of six instead of five radiotherapy fractions per week improves the tumour response in squamous-cell carcinoma....

  5. DISSOLVED ORGANIC-MATTER, CADMIUM, COPPER AND ZINC IN PIG SLURRY-SIZE AND SOIL SOLUTION-SIZE EXCLUSION CHROMATOGRAPHY FRACTIONS

    NARCIS (Netherlands)

    DELCASTILHO, P; DALENBERG, JW; BRUNT, K; BRUINS, AP

    1993-01-01

    Sephadex size exclusion chromatography was used to prepare molecular size fractions from liquid pig slurry, before and after aerobic interaction with a loamy-sand soil. In the liquid fractions organic matter was characterized and some components were identified. The distribution of zinc and copper

  6. Adaptive fractionation therapy: I. Basic concept and strategy

    International Nuclear Information System (INIS)

    Lu Weiguo; Chen Mingli; Chen Quan; Ruchala, Kenneth; Olivera, Gustavo

    2008-01-01

    Radiotherapy is fractionized to increase the therapeutic ratio. Fractionation in conventional treatment is determined as part of the prescription, and a fixed fraction size is used for the whole course of treatment. Due to patients' day-to-day variations on the relative distance between the tumor and the organs at risk (OAR), a better therapeutic ratio may be attained by using an adaptive fraction size. Intuitively, we want to use a larger fraction size when OAR and the tumor are far apart and a smaller fraction size when OAR and the tumor are close to each other. The concept and strategies of adaptive fractionation therapy (AFT) are introduced in this paper. AFT is an on-line adaptive technique that utilizes the variations of internal structures to get optimal OAR sparing. Changes of internal structures are classified as different configurations according to their feasibility to the radiation delivery. A priori knowledge is used to describe the probability distribution of these configurations. On-line processes include identifying the configuration via daily image guidance and optimizing the current fraction size. The optimization is modeled as a dynamic linear programming problem so that at the end of the treatment course, the tumor receives the same planned dose while OAR receives less dose than the regular fractionation delivery. Extensive simulations, which include thousands of treatment courses with each course consisting of 40 fractions, are used to test the efficiency and robustness of the presented technique. The gains of OAR sparing depend on the variations on configurations and the bounds of the fraction size. The larger the variations and the looser the bounds are, the larger the gains will be. Compared to the conventional fractionation technique with 2 Gy/fraction in 40 fractions, for a 20% variation on tumor-OAR configurations and [1 Gy, 3 Gy] fraction size bounds, the cumulative OAR dose with adaptive fractionation is 3-8 Gy, or 7-20% less than that

  7. Skin toxicity during hypo fractionated breast irradiation in patient with early breast cancer

    International Nuclear Information System (INIS)

    Petrova, Deva; Smichkoska, Snezhana

    2013-01-01

    Radiotherapy is an important component in the treatment of breast cancer. (1) Many women with an early stage of breast cancer are candidates for a breast conservation therapy, which combines both conservative surgery and radiotherapy. (2) According to the data from some series, an estimated 90% of the patients treated with radiotherapy for breast cancer will develop a degree of radiation-induced dermatitis. (3) The severity of the skin reactions during and following the breast irradiation is influenced by both treatment-related and patient-related factors. The treatment - related factors include the fraction size (the dose delivered with each treatment), the total dose delivered, the volume of tissue treated, the type of radiation (4) and the addition of chemotherapy. (5) The patient-related factors include breast size, smoking, axillary lymphocele drainage before treatment, age, and infection of the surgical wound. (6) A hypo fractionation radiotherapy is alternative for a standard fractionation radiotherapy for women with early stage of breast cancer after conservative surgery. The aim of the study was to analyse the acute skin reactions during a hypo fractionated radiotherapy in patients with early breast cancer at our institution. Materials and methods: Twenty patients with early stage of breast cancer (Stadium I and II) and conservative surgery (quadrantectomy of breast with ipsilateral axillary dissection) were analysed. The patients were treated with 6MV x rays on LINAC, using tangential fields with 2.65Gy per fraction and the total dose prescribed to target volume was 42,4 Gy. These patients were observed for acute skin toxicity during the second week and at the end of the treatment. We evaluated dryness, epilation, pigmentation, changes and eritema, dry desquamation (clinically characterized by scaling and pruritus) and moist desquamation (characterized by serious oozing and exposure of the dermis). By using the radiation therapy oncology group’s (RTOG

  8. Radiation-included brachial plexus injury; Follow-up of two different fractionation schedules

    Energy Technology Data Exchange (ETDEWEB)

    Powell, S.; Cooke, J.; Parsons, C. (Royal Marsden Hospital, London (UK))

    1990-07-01

    All 449 breast cancer patients treated with post-operative radiotherapy to the breast and lymph nodes between 1982 and 1984 have been followed for 3-5.5 years. In this group two different fractionation schedules were used, one five times a fortnight and one daily, both over 6 weeks. The calculated dose to the brachial plexus was 45 Gy in 15 fractions or 5e Gy in 30 fractions. These schedules are equivalent doses using the standard NSD formula. The diagnosis of a brachial plexus injury was made clinically and computed tomography from recurrent disease. The actuarial incidence of a radiation-induced brachial plexus injury for the whole group was 4.9% at 5.5 years. No cases were seen in the first 10 months following radiotherapy. The incidence rises between 1 and 4 years and then starts to plateau. When the large fraction size group is compared with the small fraction size group the incidence at 5.5 years is 5.9% and 1.0%, respectively (p 0.09). Two different treatment techniques were used in this group but were not found to contribute to the probability of developing a brachial plexud injury. It is suggested that radiation using large doses per fraction are less well tolerated by the brachial plexus than small doses per fraction; a commonly used fractionation schedule such as 45 Gy in 15 fractions may give unacceptably high brachial plexus morbidity; and the of small doses per fraction or avoiding lymphatic irradiation is advocated. (author). 13 refs.; 6 figs.; 1 tab.

  9. MRI-guided single fraction ablative radiotherapy for early-stage breast cancer : a brachytherapy versus volumetric modulated arc therapy dosimetry study

    NARCIS (Netherlands)

    Charaghvandi, Ramona K; den Hartogh, Mariska D; van Ommen, Anne-Mar L N; de Vries, Wilfred J H; Scholten, Vincent; Moerland, Rien; Philippens, Mariëlle E P; Schokker, Rogier I; van Vulpen, Marco; van Asselen, B; van den Bongard, Desirée H J G

    2015-01-01

    BACKGROUND AND PURPOSE: A radiosurgical treatment approach for early-stage breast cancer has the potential to minimize the patient's treatment burden. The dosimetric feasibility for single fraction ablative radiotherapy was evaluated by comparing volumetric modulated arc therapy (VMAT) with an

  10. Stereotactic radiosurgery vs. fractionated radiotherapy for tumor control in vestibular schwannoma patients

    DEFF Research Database (Denmark)

    Persson, Oscar; Bartek, Jiri; Shalom, Netanel Ben

    2017-01-01

    OBJECTIVE: Repeated controlled studies have revealed that stereotactic radiosurgery is better than microsurgery for patients with vestibular schwannoma (VS) ... to patients treated with fractionated stereotactic radiotherapy. RESULTS: No randomized controlled trial (RCT) was identified. None of the identified controlled studies comparing SRS with FSRT were eligible according to the inclusion criteria. Nineteen case series on SRS (n = 17) and FSRT (n = 2) were...... included in the systematic review. Loss of tumor control necessitating a new VS-targeted intervention was found in an average of 5.0% of the patients treated with SRS and in 4.8% treated with FSRT. Mean deterioration ratio for patients with serviceable hearing before treatment was 49% for SRS and 45...

  11. A case of gastric endocrine cell carcinoma which was significantly reduced in size by radiotherapy

    International Nuclear Information System (INIS)

    Azakami, Kiyoshi; Nishida, Kouji; Tanikawa, Ken

    2016-01-01

    In 2010, the World Health Organization classified gastric neuroendocrine tumors (NETs) into three types: NET grade (G) 1, NET G2 and neuroendocrine carcinoma (NEC). NECs are associated with a very poor prognosis. The patient was an 84-year-old female who was initially diagnosed by gastrointestinal endoscope with type 3 advanced gastric cancer with stenosis of the gastric cardia. Her overall status and performance status did not allow for operations or intensive chemotherapy. Palliative radiotherapy was performed and resulted in a significant reduction in the size of the tumor as well as the improvement of the obstructive symptoms. She died 9 months after radiotherapy. An autopsy provided a definitive diagnosis of gastric endocrine cell carcinoma, and the effectiveness of radiotherapy was pathologically-confirmed. Palliative radiotherapy may be a useful treatment option for providing symptom relief, especially for old patients with unresectable advanced gastric neuroendocrine carcinoma. (author)

  12. Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP

    International Nuclear Information System (INIS)

    Astudillo V, A. J.; Mitsoura, E.; Paredes G, L.; Resendiz G, G.

    2014-08-01

    At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

  13. Adjuvant radiotherapy for cutaneous melanoma: Comparing hypofractionation to conventional fractionation

    International Nuclear Information System (INIS)

    Chang, Daniel T.; Amdur, Robert J.; Morris, Christopher G. M.S.; Mendenhall, William M.

    2006-01-01

    Purpose: To examine locoregional control after adjuvant radiotherapy (RT) for cutaneous melanoma and compare outcomes between conventional fractionation and hypofractionation. Methods and Materials: Between January 1980 and June 2004, 56 patients with high-risk disease were treated with adjuvant RT. Indications for RT included: recurrent disease, cervical lymph node involvement, lymph nodes >3 cm, more than three lymph nodes involved, extracapsular extension, gross residual disease, close or positive margins, or satellitosis. Hypofractionation was used in 41 patients (73%) and conventional fractionation was used in 15 patients (27%). Results: The median age was 61 years (21->90). The median follow-up among living patients was 4.4 years (range, 0.6-14.4 years). The primary site was located in the head and neck in 49 patients (87%) and below the clavicles in 7 patients (13%). There were 7 in-field locoregional failures (12%), 3 out-of-field regional failures (5%), and 24 (43%) distant failures. The 5-year in-field locoregional control (ifLRC) and freedom from distant metastases (FFDM) rates were 87% and 43%, respectively. The 5-year cause-specific (CSS) and overall survival (OS) was 57% and 46%, respectively. The only factor associated with ifLRC was satellitosis (p = 0.0002). Nodal involvement was the only factor associated with FFDM (p = 0.0007), CSS (p = 0.0065), and OS (p = 0.016). Two patients (4%) who experienced severe late complications, osteoradionecrosis of the temporal bone and radiation plexopathy, and both received hypofractionation (5%). Conclusions: Although surgery and adjuvant RT provides excellent locoregional control, distant metastases remain the major cause of mortality. Hypofractionation and conventional fractionation are equally efficacious

  14. Single-Fraction Intraoperative Radiotherapy for Breast Cancer: Early Cosmetic Results

    International Nuclear Information System (INIS)

    Beal, Kathryn; McCormick, Beryl; Zelefsky, Michael J.; Borgen, Patrick; Fey, Jane; Goldberg, Jessica; Sacchini, Virgilio

    2007-01-01

    Purpose: To evaluate the cosmetic outcome of patients treated with wide local excision and intraoperative radiotherapy for early-stage breast cancer. Methods and Materials: A total of 50 women were treated on a pilot study to evaluate the feasibility of intraoperative radiotherapy at wide local excision. The eligibility criteria included age >60, tumor size ≤2.0 cm, clinically negative lymph nodes, and biopsy-established diagnosis. After wide local excision, a custom breast applicator was placed in the excision cavity, and a dose of 20 Gy was prescribed to a depth of 1 cm. After 18 patients were treated, the dose was constrained laterally to 18 Gy. The cosmetic outcome was evaluated by photographs at baseline and at 6 and 12 months postoperatively. Four examiners graded the photographs for symmetry, edema, discoloration, contour, and scarring. The grades were evaluated in relationship to the volume of irradiated tissue, tumor location, and dose at the lateral aspects of the cavity. Results: The median volume of tissue receiving 100% of the prescription dose was 47 cm 3 (range, 20-97 cm 3 ). Patients with ≤47 cm 3 of treated tissue had better cosmetic outcomes than did the women who had >47 cm 3 of treated tissue. Women who had received 18 Gy at the lateral aspects of their cavities had better cosmetic outcomes than did women who had received 20 Gy at the lateral aspects. When comparing the 6- and 12-month results, the scores remained stable for 63%, improved for 17%, and worsened for 20%. Conclusion: Intraoperative radiotherapy appears feasible for selected patients. A favorable cosmetic outcome appears to be related to a smaller treatment volume. The cosmetic outcome is acceptable, although additional follow-up is necessary

  15. Oxygen tension in transplanted mouse osteosarcomas during fractionated high-LET- and low-LET radiotherapy - predictive aspects for choosing beam quality?

    International Nuclear Information System (INIS)

    Auberger, T.; Thuerriegel, B.; Freude, T.; Weissfloch, L.; Kneschaurek, P.; Molls, M.; Senekowitsch-Schmidtke, R.; Wagner, F.M.

    1999-01-01

    Murine OTS64 - osteosarcomas were tranplanted in 102 balb-C mice and irradiated by 36 Gy of photons in fractions of 3 Gy five times a week (group P-36/3) or by 12 Gy of reactor fission neutrons in fractions of 2 Gy two times a week (group N-12/2). Irradiations started at a tumor volume of 500 to 600 mm 3 . A third group received no radiotherapy, but all investigations (group CG). Tumor volume and tumor oxygenation were measured once a week under therapy and during three weeks after therapy. For in vivo-evaluation of oxygen status a computerized polarographic needle electrode system (KIMOC pO 2 histograph, Eppendorf) was used. The median pO 2 and the hypoxic fraction (pO 2 values 2 decreased from 20 mm to 8 mm Hg and the hypoxic fraction increased from 7% to 31%. After fractionated photon therapy a growth delay of three weeks was observed. Six weeks after beginning of the irradiation the median tumor volume had been doubled again. After fission neutron therapy growth delay continued until the end of the follow-up period. In both of the irradiated groups a significant decrease of median pO 2 values and an increase of the hypoxic fraction were observed under radiotherapy. Hypoxia was more intensive after neutrons with a decrease of the median pO 2 from 20 mm Hg to 1 mm Hg vs. 10 mm Hg after photon therapy and with an increase of the hypoxic fraction from 7% to 78% vs. 36% respectively. Two weeks after the end of therapy the median pO 2 and the hypoxic fraction of both treated groups reached the levels prior to irradiation indicating a complete reoxygenation. (orig.)

  16. Modelling the interplay between hypoxia and proliferation in radiotherapy tumour response

    International Nuclear Information System (INIS)

    Jeong, J; Deasy, J O; Shoghi, K I

    2013-01-01

    A tumour control probability computational model for fractionated radiotherapy was developed, with the goal of incorporating the fundamental interplay between hypoxia and proliferation, including reoxygenation over a course of radiotherapy. The fundamental idea is that the local delivery of oxygen and glucose limits the amount of proliferation and metabolically-supported cell survival a tumour sub-volume can support. The model has three compartments: a proliferating compartment of cells receiving oxygen and glucose; an intermediate, metabolically-active compartment receiving glucose; and a highly hypoxic compartment of starving cells. Following the post-mitotic cell death of proliferating cells, intermediate cells move into the proliferative compartment and hypoxic cells move into the intermediate compartment. A key advantage of the proposed model is that the initial compartmental cell distribution is uniquely determined from the assumed local growth fraction (GF) and volume doubling time (T D ) values. Varying initial cell state distributions, based on the local (voxel) GF and T D , were simulated. Tumour response was simulated for head and neck squamous cell carcinoma using relevant parameter values based on published sources. The tumour dose required to achieve a 50% local control rate (TCD 50 ) was found for various GFs and T D ’s, and the effect of fraction size on TCD 50 was also evaluated. Due to the advantage of reoxygenation over a course of radiotherapy, conventional fraction sizes (2–2.4 Gy fx −1 ) were predicted to result in smaller TCD 50 's than larger fraction sizes (4–5 Gy fx –1 ) for a 10 cc tumour with GFs of around 0.15. The time to eliminate hypoxic cells (the reoxygenation time) was estimated for a given GF and decreased as GF increased. The extra dose required to overcome accelerated stem cell accumulation in longer treatment schedules was estimated to be 0.68 Gy/day (in EQD2 6.6 ), similar to published values derived from clinical

  17. Radiotherapy-induced emesis. An overview

    International Nuclear Information System (INIS)

    Feyer, P.; Buchali, A.; Hinkelbein, M.; Budach, V.; Zimmermann, J.S.; Titlbach, O.J.

    1998-01-01

    Background: A significant number of patients receiving radiotherapy experience the distressing side effects of emesis and nausea. These symptoms are some of the most distressing problems for the patients influencing their quality of life. Methods: International study results concerning radiotherapy-induced emesis are demonstrated. A German multicenter questionnaire examining the strategies to prevent or to treat radiotherapy-induced nausea and emesis is presented. An international analysis concerning incidence of emesis and nausea in fractionated radiotherapy patients is discussed. Finally the consensus of the consensus conference on antiemetic therapy from the Perugia International Cancer Conference V is introduced. Results: Untreated emesis can lead to complications like electrolyte disorders, dehydration, metabolic disturbances and nutrition problems with weight loss. Prophylactic antiemetics are often given to patients receiving single high-dose radiotherapy to the abdomen. A survey has revealed that antiemetic prophylaxis is not routinely offered to the patients receiving fractionated radiotherapy. However, there is a need for an effective treatment of emesis for use in this group of patients, too. In 20% of patients nausea and emesis can cause a treatment interruption because of an inadequate control of symptoms. Like in chemotherapy strategies there exist high, moderate, and low emetogenic treatment regimens in radiotherapy as well. The most emetogenic potential has the total body irradiation followed by radiotherapy to the abdomen. Radiotherapy induced emesis can be treated effectively with conventional antiemetics up to 50%. Conclusions: Studies with total body irradiation, fractionated treatment and high-dose single exposures have cleary demonstrated the value of 5-HT3-receptor antagonist antiemetics. There is a response between 60 and 97%. There is no difference in the efficacy of the different 5-HT3-antagonists. High-risk patients should be prophylactic

  18. Misonidazole in fractionated radiotherapy: are many small fractions best

    International Nuclear Information System (INIS)

    Denekamp, J.; McNally, N.J.; Fowler, J.F.; Joiner, M.C.

    1980-01-01

    The largest sensitizing effect is always demonstrated with six fractions, each given with 2 g/m 2 of misonidazole. In the absence of reoxygenation a sensitizer enhancement ratio of 1.7 is predicted, but this falls to 1.1-1.2 if extensive reoxygenation occurs. Less sensitization is observed with 30 fractions, each with 0.4 g/m 2 of drug. However, for clinical use, the important question is which treatment kills the maximum number of tumour cells. Many of the simulations predict a marked disadvantage of reducing the fraction number for X rays alone. The circumstances in which this disadvantage is offset by the large Sensitizer enhancement ratio values with a six-fraction schedule are few. The model calculations suggest that many small fractions, each with a low drug dose, are safest unless the clinician has some prior knowledge that a change in fraction number is not disadvantageous. (author)

  19. Long term results of hypo-fractionated mammary radiotherapy as exclusive treatment of elderly patients suffering from a beast cancer; Resultats a long terme de la radiotherapie mammaire hypofractionnee comme traitement exclusif des patientes agees souffrant d'un cancer du sein

    Energy Technology Data Exchange (ETDEWEB)

    Chargari, C.; Kirova, Y.; Laki, F.; Savignoni, A.; Dorval, D.; Dendale, R.; Bollet, M.; Fourquet, A.; Campana, F. [Institut Curie, 75 - Paris (France)

    2010-10-15

    The author discuss the results obtained on 29 elderly patients exclusively treated between 1995 and 1999 by mammary irradiation (32.5 Gy) in 5 fractions over 5 weeks, and then with a lower additional irradiation (13 Gy) in two fractions. They discuss the efficiency of this hypo-fractionated radiotherapy without breast conserving surgery. Short communication

  20. Evaluation of uneven fractionation radiotherapy of cervical lymph node-metastases by linear quadratic model

    International Nuclear Information System (INIS)

    Sasaki, Takehito; Kamata, Rikisaburo; Urahashi, Shingo; Yamaguchi, Tetsuji.

    1993-01-01

    One hundred and sixty-nine cervical lymph node-metastases from head and neck squamous cell carcinomas treated with either even fractionation or uneven fractionation regimens were analyzed in the present investigation. Logistic multivariate regression analysis indicated that: type of fractionation (even vs uneven), size of metastases, T value of primary tumors, and total dose are independent variables out of 18 variables that significantly influenced the rate of tumor clearance. The data, with statistical bias corrected by the regression equation, indicated that the uneven fractionation scheme significantly improved the rate of tumor clearance for the same size of metastases, total dose, and overall time compared to the even fractionation scheme. Further analysis by a linear-quadratic cell survival model indicated that the clinical improvement by uneven fractionation might not be explained entirely by a larger dose per fraction. It is suggested that tumor cells irradiated with an uneven fractionation regimen might repopulate more slowly, or they might be either less hypoxic or redistributed in a more radiosensitive phase in the cell cycle than those irradiated with even fractionation. This conclusion is clearly not definite, but it is suitable, pending the results of further investigation. (author)

  1. Long-Term Outcomes of Vestibular Schwannomas Treated With Fractionated Stereotactic Radiotherapy: An Institutional Experience

    International Nuclear Information System (INIS)

    Kapoor, Sumit; Batra, Sachin; Carson, Kathryn; Shuck, John; Kharkar, Siddharth; Gandhi, Rahul; Jackson, Juan; Wemmer, Jan; Terezakis, Stephanie; Shokek, Ori; Kleinberg, Lawrence; Rigamonti, Daniele

    2011-01-01

    Purpose: We assessed clinical outcome and long-term tumor control after fractionated stereotactic radiotherapy (FSRT) for unilateral schwannoma. Methods and Materials: Between 1995 and 2007, 496 patients were treated with fractionated stereotactic radiotherapy at Johns Hopkins Hospital (Baltimore, MD); 385 patients had radiologic follow-up that met the inclusion criteria. The primary endpoint was treatment failure. Secondary endpoints were radiologic progression and clinical outcome. Logistic regression analysis assessed the association of age, race, tumor side, sex, and pretreatment symptoms. Results: In 11 patients (3%) treatment failed, and they required salvage (microsurgical) treatment. Radiologic progression was observed in 116 patients (30.0%), including 35 patients (9%) in whom the treatment volume more than doubled during the follow-up period, although none required surgical resection. Tumors with baseline volumes of less than 1 cm 3 were 18.02 times more likely to progress than those with tumor volumes of 1 cm 3 or greater (odds ratio, 18.02; 95% confidence interval, 4.25-76.32). Treatment-induced neurologic morbidity included 8 patients (1.6%) with new facial weakness, 12 patients (2.8%) with new trigeminal paresthesias, 4 patients (0.9%) with hydrocephalus (1 communicating and 3 obstructive), and 2 patients (0.5%) with possibly radiation-induced neoplasia. Conclusions: Although the rate of treatment failure is low (3%), careful follow-up shows that radiologic progression occurs frequently. When reporting outcome, the 'no salvage surgery needed' and 'no additional treatment needed' criteria for treatment success need to be complemented by the radiologic data.

  2. Micro nutrient status and their distribution in aggregate-size fractions ...

    African Journals Online (AJOL)

    Micro nutrients are particularly sensitive to changes in land use and their availability in soil is influenced by their distribution and storage in stable aggregate fractions. Micro nutrient, (Fe, Mn and Zn) status and their storage in stable aggregate-size fractions in forested, rubber plantation, oil palm plantation, plantain plantation ...

  3. A Population-based Study of the Fractionation of Palliative Radiotherapy for Bone Metastasis in Ontario

    International Nuclear Information System (INIS)

    Kong, Weidong; Zhang-Salomons, Jina; Hanna, Timothy P.; Mackillop, William J.

    2007-01-01

    Purpose: To describe the use of palliative radiotherapy (PRT) for bone metastases in Ontario between 1984 and 2001 and identify factors associated with the choice of fractionation. Methods and Materials: Electronic RT records from the nine provincial RT centers in Ontario were linked to the Ontario Cancer Registry to identify all courses of PRT for bone metastases. Results: Between 1984 and 2001, 44,884 patients received 74,432 courses of PRT for bone metastases in Ontario. The mean number of courses per patient was 1.7, and 65% of patients received only a single course of PRT for bone metastasis. The mean number of fractions per course was 3.9. The proportion of patients treated with a single fraction increased from 27.2% in 1984-1986 to 40.3% in 1987-1992 and decreased thereafter. Single fractions were used more frequently in patients with a shorter life expectancy, in older patients, and in patients who lived further from an RT center. Single fractions were used more frequently when the prevailing waiting time for RT was longer. There were wide variations in the use of single fractions among the different RT centers (intercenter range, 11.8-62.3%). Intercenter variations persisted throughout the study period and were not explained by differences in case mix. Conclusions: Despite increasing evidence of the effectiveness of single-fraction PRT for bone metastases, most patients continued to receive fractionated PRT throughout the two decades of this study. Single fractions were used more frequently when waiting times were longer. There was persistent, unexplained variation in the fractionation of PRT among different centers

  4. Integration of surgery with fractionated stereotactic radiotherapy for treatment of nonfunctioning pituitary macroadenomas

    International Nuclear Information System (INIS)

    Paek, Sun Ha; Downes, M. Beverly; Bednarz, Greg; Keane, William M.; Werner-Wasik, Maria; Curran, Walter J.; Andrews, David W.

    2005-01-01

    Objective: To evaluate the efficacy of fractionated stereotactic radiotherapy (FSRT) after surgery in the management of residual or recurrent nonfunctioning pituitary adenomas with respect to tumor control and the development of complications. Methods and materials: The clinical records of patients with nonfunctioning pituitary adenomas who underwent FSRT were retrospectively analyzed. For newly diagnosed tumors, transsphenoidal surgery was performed, and, if residual tumor was identified at 3 months, FSRT was performed. If significant tumor volume persisted, transcranial surgery was performed before FSRT. We originally initiated FSRT with 2-Gy fractions to 46 Gy. We escalated the dose to 50.4 Gy thereafter. As a final modification, we dropped the daily dose to 1.8-Gy fractions delivered within 6 weeks. High-dose conformality and homogeneity was achieved with arc beam shaping and differential beam weighting. The radiographic, endocrinologic, and visual outcomes after FSRT were evaluated. Results: The 68 patients included 36 males and 32 females with an age range of 15-81 years. The median follow-up was 30 months (range, 2-82 months), and the median tumor volume was 6.2 cm 3 . Of the 68 patients, 20 were treated to 46 Gy and 48 to 50-52.2 Gy. Most were treated to 50.4 Gy. Eleven patients had recurrent tumors, 54 had residual tumors, and no surgery was performed in 3 patients before FSRT. We noted no radiation-induced acute or late toxicities, except for radiation-induced optic neuropathy in 2 patients. At latest follow-up, the tumor had decreased in size in 26 patients and remained stable in 41 of the 42 remaining patients. Of the 68 patients, 4 (6%) developed hypopituitarism at 6, 11, 12, and 17 months after FSRT. Reviewing available serial Humphrey visual fields, visual fields were objectively improved in 28 patients, and remained stable in 24 patients, and worsened in 2 patients. Conclusion: The findings of this analysis support the use of surgery followed by

  5. A randomised phase II trial of Stereotactic Ablative Fractionated radiotherapy versus Radiosurgery for Oligometastatic Neoplasia to the lung (TROG 13.01 SAFRON II)

    International Nuclear Information System (INIS)

    Siva, Shankar; Kron, Tomas; Bressel, Mathias; Haas, Marion; Mai, Tao; Vinod, Shalini; Sasso, Giuseppe; Wong, Wenchang; Le, Hien; Eade, Thomas; Hardcastle, Nicholas; Chesson, Brent; Pham, Daniel; Høyer, Morten; Montgomery, Rebecca; Ball, David

    2016-01-01

    Stereotactic ablative body radiotherapy (SABR) is emerging as a non-invasive method for precision irradiation of lung tumours. However, the ideal dose/fractionation schedule is not yet known. The primary purpose of this study is to assess safety and efficacy profile of single and multi-fraction SABR in the context of pulmonary oligometastases. The TROG 13.01/ALTG 13.001 clinical trial is a multicentre unblinded randomised phase II study. Eligible patients have up to three metastases to the lung from any non-haematological malignancy, each < 5 cm in size, non-central targets, and have all primary and extrathoracic disease controlled with local therapies. Patients are randomised 1:1 to a single fraction of 28Gy versus 48Gy in four fractions of SABR. The primary objective is to assess the safety of each treatment arm, with secondary objectives including assessment of quality of life, local efficacy, resource use and costs, overall and disease free survival and time to distant failure. Outcomes will be stratified by number of metastases and origin of the primary disease (colorectal versus non-colorectal primary). Planned substudies include an assessment of the impact of online e-Learning platforms for lung SABR and assessment of the effect of SABR fractionation on the immune responses. A total of 84 patients are required to complete the study. Fractionation schedules have not yet been investigated in a randomised fashion in the setting of oligometastatic disease. Assuming the likelihood of similar clinical efficacy in both arms, the present study design allows for exploration of the hypothesis that cost implications of managing potentially increased toxicities from single fraction SABR will be outweighed by costs associated with delivering multiple-fraction SABR

  6. Twice-a-day fractionated radiotherapy with chemotherapy for advanced laryngeal cancer

    International Nuclear Information System (INIS)

    Karasawa, Kumiko; Okawa, Tomohiko

    1998-01-01

    Twenty-five patients with advanced laryngeal cancer were treated with twice-a-day fractionated radiotherapy (TDFR) to a total dose of 65 Gy to 82 Gy combined with chemotherapy of CDDP and 5-FU between 1994 and 1997. Twenty-two cases (88%) became complete response and 9 cases recurred. The relapse-free rate at 2 years was 49.8%. The laryngeal conserving rate at 2 years was 71.0%, the actuarial 2-year survival rate was 89.9%. In induction chemotherapy (12 cases) no severe toxicity has been observed. In TDFR with concurrent chemotherapy (22 cases), grade 3 hematological toxicity was observed in 4 cases and grade 4 mucosal toxicity in 16 cases. Based on this investigation, it is concluded that TDFR with chemotherapy is a promising modality for advanced laryngeal cancer and toxicity is acceptable. (author)

  7. Metals in particle-size fractions of the soils of five European cities

    International Nuclear Information System (INIS)

    Ajmone-Marsan, F.; Biasioli, M.; Kralj, T.; Grcman, H.; Davidson, C.M.; Hursthouse, A.S.; Madrid, L.; Rodrigues, S.

    2008-01-01

    Soils from Aveiro, Glasgow, Ljubljana, Sevilla and Torino have been investigated in view of their potential for translocation of potentially toxic elements (PTE) to the atmosphere. Soils were partitioned into five size fractions and Cr, Cu, Ni, Pb and Zn were measured in the fractions and the whole soil. All PTE concentrated in the <10 μm fraction. Cr and Ni concentrated also in the coarse fraction, indicating a lithogenic contribution. An accumulation factor (AF) was calculated for the <2 and <10 μm fraction. The AF values indicate that the accumulation in the finer fractions is higher where the overall contamination is lower. AF for Cr and Ni are particularly low in Glasgow and Torino. An inverse relationship was found between the AF of some metals and the percentage of <10 μm particles that could be of use in risk assessment or remediation practices. - Metals in size fractions of urban soils

  8. Determining inter-fractional motion of the uterus using 3D ultrasound imaging during radiotherapy for cervical cancer

    DEFF Research Database (Denmark)

    Baker, Mariwan; Jensen, Jørgen Arendt; Behrens, Claus F.

    2014-01-01

    Uterine positional changes can reduce the accuracy of radiotherapy for cervical cancer patients. The purpose of this study was to; 1) Quantify the inter-fractional uterine displacement using a novel 3D ultrasound (US) imaging system, and 2) Compare the result with the bone match shift determined ...... uterus. Uterine shifts based on US imaging contains relative uterus-bone displacement, which is not taken into consideration using CBCT bone match....

  9. Risk Factors of Developing Long-Lasting Breast Pain After Breast Cancer Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lundstedt, Dan, E-mail: dan.lundstedt@vgregion.se [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden); Gustafsson, Magnus [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Steineck, Gunnar [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Division of Clinical Cancer Epidemiology, Department of Oncology-Pathology, the Karolinska Institute, Stockholm (Sweden); Malmstroem, Per [Skane Department of Oncology, Skane University Hospital, Lund (Sweden); Alsadius, David [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden); Sundberg, Agnetha [Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Wilderaeng, Ulrica [Division of Clinical Cancer Epidemiology, Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg (Sweden); Holmberg, Erik [Oncologic Centre, Sahlgrenska University Hospital, Gothenburg (Sweden); Johansson, Karl-Axel [Department of Therapeutic Radiation Physics, Sahlgrenska University Hospital, Gothenburg (Sweden); Karlsson, Per [Department of Oncology, Sahlgrenska University Hospital, Gothenburg (Sweden)

    2012-05-01

    Purpose: Postoperative radiotherapy decreases breast cancer mortality. However, studies have revealed a long-lasting breast pain among some women after radiotherapy. The purpose of this study was to identify risk factors that contribute to breast pain after breast cancer radiotherapy. Methods and Materials: We identified 1,027 recurrence-free women in two cohorts of Swedish women treated for breast cancer. The women had breast-conserving surgery and postoperative radiotherapy, the breast was treated to 48 Gy in 2.4-Gy fractions or to 50 Gy in 2.0-Gy fractions. Young women received a boost of up to 16 Gy. Women with more than three lymph node metastases had locoregional radiotherapy. Systemic treatments were given according to health-care guidelines. Three to 17 years after radiotherapy, we collected data using a study-specific questionnaire. We investigated the relation between breast pain and potential risk modifiers: age at treatment, time since treatment, chemotherapy, photon energy, fractionation size, boost, loco-regional radiotherapy, axillary surgery, overweight, and smoking. Results: Eight hundred seventy-seven women (85%) returned the questionnaires. Among women up to 39 years of age at treatment, 23.1% had breast pain, compared with 8.7% among women older than 60 years (RR 2.66; 95% CI 1.33-5.36). Higher age at treatment (RR 0.96; 95% CI 0.94-0.98, annual decrease) and longer time since treatment (RR 0.93; 95% CI 0.88-0.98, annual decrease) were related to a lower occurrence of breast pain. Chemotherapy increased the occurrence of breast pain (RR 1.72; 95% CI 1.19-2.47). In the multivariable model only age and time since treatment were statistically significantly related to the occurrence of breast pain. We found no statistically significant relation between breast pain and the other potential risk modifiers. Conclusions: Younger women having undergone breast-conserving surgery with postoperative radiotherapy report a higher occurrence of long

  10. Critical dose and toxicity index of organs at risk in radiotherapy: Analyzing the calculated effects of modified dose fractionation in non–small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pedicini, Piernicola, E-mail: ppiern@libero.it [Service of Medical Physics, I.R.C.C.S. Regional Cancer Hospital C.R.O.B, Rionero in Vulture (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Benassi, Marcello [Service of Medical Physics, Scientific Institute of Tumours of Romagna I.R.S.T., Meldola (Italy); Caivano, Rocchina [Service of Medical Physics, I.R.C.C.S. Regional Cancer Hospital C.R.O.B, Rionero in Vulture (Italy); Fiorentino, Alba [U.O. of Radiotherapy, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy); Nappi, Antonio [U.O. of Nuclear Medicine, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy); Salvatore, Marco [U.O. of Nuclear Medicine, I.R.C.C.S. SDN Foundation, Naples (Italy); Storto, Giovanni [U.O. of Nuclear Medicine, I.R.C.C.S. Regional Cancer Hospital C.R.O.B., Rionero in Vulture (Italy)

    2014-04-01

    To increase the efficacy of radiotherapy for non–small cell lung cancer (NSCLC), many schemes of dose fractionation were assessed by a new “toxicity index” (I), which allows one to choose the fractionation schedules that produce less toxic treatments. Thirty-two patients affected by non resectable NSCLC were treated by standard 3-dimensional conformal radiotherapy (3DCRT) with a strategy of limited treated volume. Computed tomography datasets were employed to re plan by simultaneous integrated boost intensity-modulated radiotherapy (IMRT). The dose distributions from plans were used to test various schemes of dose fractionation, in 3DCRT as well as in IMRT, by transforming the dose-volume histogram (DVH) into a biological equivalent DVH (BDVH) and by varying the overall treatment time. The BDVHs were obtained through the toxicity index, which was defined for each of the organs at risk (OAR) by a linear quadratic model keeping an equivalent radiobiological effect on the target volume. The less toxic fractionation consisted in a severe/moderate hyper fractionation for the volume including the primary tumor and lymph nodes, followed by a hypofractionation for the reduced volume of the primary tumor. The 3DCRT and IMRT resulted, respectively, in 4.7% and 4.3% of dose sparing for the spinal cord, without significant changes for the combined-lungs toxicity (p < 0.001). Schedules with reduced overall treatment time (accelerated fractionations) led to a 12.5% dose sparing for the spinal cord (7.5% in IMRT), 8.3% dose sparing for V{sub 20} in the combined lungs (5.5% in IMRT), and also significant dose sparing for all the other OARs (p < 0.001). The toxicity index allows to choose fractionation schedules with reduced toxicity for all the OARs and equivalent radiobiological effect for the tumor in 3DCRT, as well as in IMRT, treatments of NSCLC.

  11. Norm- and hypo-fractionated radiotherapy is capable of activating human dendritic cells.

    Science.gov (United States)

    Kulzer, Lorenz; Rubner, Yvonne; Deloch, Lisa; Allgäuer, Andrea; Frey, Benjamin; Fietkau, Rainer; Dörrie, Jan; Schaft, Niels; Gaipl, Udo S

    2014-10-01

    Despite the transient immunosuppressive properties of local radiotherapy (RT), this classical treatment modality of solid tumors is capable of inducing immunostimulatory forms of tumor-cell death. The resulting 'immunotoxicity' in the tumor, but not in healthy tissues, may finally lead to immune-mediated destruction of the tumor. However, little is known about the best irradiation scheme in this setting. This study examines the immunological effects of differently irradiated human colorectal tumor cells on human monocyte-derived dendritic cells (DC). Human SW480 tumor cells were irradiated with a norm-fractionation scheme (5 × 2 Gy), a hypo-fractionated protocol (3 × 5 Gy), and with a high single irradiation dose (radiosurgery; 1 × 15 Gy). Subsequently, human immature DC (iDC) were co-incubated with supernatants (SN) of these differently treated tumor cells. Afterwards, DC were analyzed regarding the expression of maturation markers, the release of cytokines, and the potential to stimulate CD4(+) T-cells. The co-incubation of iDC with SN of tumor cells exposed to norm- or hypo-fractionated RT resulted in a significantly increased secretion of the immune activating cytokines IL-12p70, IL-8, IL-6, and TNFα, compared to iDC co-incubated with SN of tumor cells that received a high single irradiation dose or were not irradiated. In addition, DC-maturation markers CD80, CD83, and CD25 were also exclusively elevated after co-incubation with the SN of fractionated irradiated tumor cells. Furthermore, the SN of tumor cells that were irradiated with norm- or hypo-fractionated RT triggered iDC to stimulate CD4(+) T-cells not only in an allogenic, but also in an antigen-specific manner like mature DC. Collectively, these results demonstrate that norm- and hypo-fractionated RT induces a fast human colorectal tumor-cell death with immunogenic potential that can trigger DC maturation and activation in vitro. Such findings may contribute to the improvement of

  12. Direct costs of radiotherapy for rectal cancer: a microcosting study.

    Science.gov (United States)

    Hanly, Paul; Céilleachair, Alan Ó; Skally, Máiréad; O'Neill, Ciaran; Sharp, Linda

    2015-05-02

    Radiotherapy provides significant benefits in terms of reducing risk of local recurrence and death from rectal cancer. Despite this, up-to-date cost estimates for radiotherapy are lacking, potentially inhibiting policy and decision-making. Our objective was to generate an up-to-date estimate of the cost of traditional radiotherapy for rectal cancer and model the impact of a range of potential efficiency improvements. Microcosting methods were used to estimate total direct radiotherapy costs for long- (assumed at 45-50 Gy in 25 daily fractions over a 5 week period) and short-courses (assumed at 25 Gy in 5 daily fractions over a one week period). Following interviews and on-site visits to radiotherapy departments in two designated cancer centers, a radiotherapy care pathway for a typical rectal cancer patient was developed. Total direct costs were derived by applying fixed and variable unit costs to resource use within each care phase. Costs included labor, capital, consumables and overheads. Sensitivity analyses were performed. Radiotherapy treatment was estimated to cost between €2,080 (5-fraction course) and €3,609 (25-fraction course) for an average patient in 2012. Costs were highest in the treatment planning phase for the short-course (€1,217; 58% of total costs), but highest in the radiation treatment phase for the long-course (€1,974: 60% of total costs). By simultaneously varying treatment time, capacity utilization rates and linear accelerator staff numbers, the base cost fell by 20% for 5-fractions: (€1,660) and 35% for 25-fractions: (€2,354). Traditional radiotherapy for rectal cancer is relatively inexpensive. Moreover, significant savings may be achievable through service organization and provision changes. These results suggest that a strong economic argument can be made for expanding the use of radiotherapy in rectal cancer treatment.

  13. Radiotherapy for breast cancer and pacemaker; Radiotherapie pour un cancer du sein et stimulateur cardiaque

    Energy Technology Data Exchange (ETDEWEB)

    Menard, J.; Campana, F.; Bollet, M.A.; Dendale, R.; Fournier-Bidoz, N.; Marchand, V.; Mazal, A.; Fourquet, A.; Kirova, Y.M. [Oncologie-radiotherapie, institut Curie, 26, rue d' Ulm, 75005 Paris (France); Kirov, K.M.; Esteve, M. [Departement d' anesthesie-reanimation-douleur, institut Curie, 75005 Paris (France)

    2011-06-15

    Purpose. - Patients with permanent cardiac pacemakers occasionally require radiotherapy. Therapeutic Irradiation may cause pacemakers to malfunction due to the effects of ionizing radiation or electromagnetic interference. We studied the breast cancer patients who needed breast and/or chest wall and lymph node irradiation to assess the feasibility and tolerance in this population of patients. Patients and methods. - From November 2008 to December 2009, more than 900 patients received radiotherapy for their breast cancer in our department using megavoltage linear accelerator (X 4-6 MV and electrons). Among them, seven patients were with permanent pacemaker. All patients have been treated to the breast and chest wall and/or lymph nodes. Total dose to breast and/or chest wall was 50 Gy/25 fractions and 46 Gy/23 fractions to lymph nodes. Patients who underwent conserving surgery followed by breast irradiation were boosted when indicated to tumour bed with 16 Gy/8 fractions. All patients were monitored everyday in presence of radiation oncologist to follow the function of their pacemaker. All pacemakers were controlled before and after radiotherapy by the patients' cardiologist. Results. - Seven patients were referred in our department for postoperative breast cancer radiotherapy. Among them, only one patient was declined for radiotherapy and underwent mastectomy without radiotherapy. In four cases the pacemaker was repositioned before the beginning of radiotherapy. Six patients, aged between 48 and 84 years underwent irradiation for their breast cancer. Four patients were treated with conserving surgery followed by breast radiotherapy and two with mastectomy followed by chest wall and internal mammary chain, supra- and infra-clavicular lymph node irradiation. The dose to the pacemaker generator was kept below 2 Gy. There was no pacemaker dysfunction observed during the radiotherapy. Conclusion. - The multidisciplinary work with position change of the pacemaker

  14. Six fractions per week of external beam radiotherapy and high-dose-rate brachytherapy for carcinoma of the uterine cervix: A phase I/II study

    International Nuclear Information System (INIS)

    Yoon, Sang Min; Huh, Seung Jae; Park, Won; Lee, Jeung Eun; Park, Young Je; Nam, Hee Rim; Lim, Do Hoon; Ahn, Yong Chan

    2006-01-01

    Purpose: This study evaluated the treatment results of external beam radiotherapy administered in six fractions per week and high-dose-rate (HDR) brachytherapy for the treatment of cervical cancer. Methods and Materials: From July 2000 to July 2003, 43 patients were enrolled in this study. The patients received 45 Gy from a 10-MV photon beam using four-field box or anterior-posterior beams. Parametrial regions and the pelvic side walls were boosted with up to 50.4 Gy using a midline block. The daily fraction dose was 1.8 Gy administered in six-weekly fractions, from Monday to Saturday. HDR brachytherapy was also delivered at doses of 24 Gy to point A in six fractions twice a week. The median follow-up time was 37 months (range, 9-60 months). Results: The median overall treatment time was 51 days for all patients (range, 44-62 days). Thirty-four patients (79.1%) achieved complete remission and 8 (18.6%) achieved partial remission after radiotherapy. Locoregional recurrence occurred in 5 patients (11.6%), and a distant metastasis was encountered in 6 patients (13.9%). The 3-year overall survival, locoregional, and distant metastasis-free survival rates were 74.7%, 87.8%, and 84.7%, respectively. Grade 2 and 3 late rectal complications were encountered in 3 (6.5%) and 1 (2.2%), respectively. There were no Grade 3 late bladder complications. Conclusions: Six fractions per week of external beam radiotherapy and HDR brachytherapy is an effective treatment for patients with a carcinoma of the uterine cervix and can be used as a possible alternative to concomitant chemoradiotherapy in elderly patients or in patients with co-morbidity

  15. Radiotherapy Treatment Planning for Testicular Seminoma

    International Nuclear Information System (INIS)

    Wilder, Richard B.; Buyyounouski, Mark K.; Efstathiou, Jason A.; Beard, Clair J.

    2012-01-01

    Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 × 1−2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior–posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior–posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

  16. Radiotherapy Treatment Planning for Testicular Seminoma

    Energy Technology Data Exchange (ETDEWEB)

    Wilder, Richard B., E-mail: richardbwilder@yahoo.com [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States); Buyyounouski, Mark K. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Efstathiou, Jason A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Beard, Clair J. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center, Boston, MA (United States)

    2012-07-15

    Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

  17. Proliferation in human tumors and optimum radiotherapy fractionation

    International Nuclear Information System (INIS)

    Fowler, J.F.; Wisconsin Univ., Madison, WI; Lindstrom, M.J.

    1991-01-01

    Within the last ten years a number of radiotherapy results have been published which enable the effect of overall time on local control to be examined. In all 12 papers a loss of local control with prolongation is shown, although not all papers show a dependence on total dose. The loss of local control per week ranges from 6 to 25% with a median value of 15%. Development of shorter radiotherapy schedules, by one or two weeks, with allocation of rapidly proliferating tumors to the shorter schedules, is recommended. (author)

  18. Radiotherapy in digestive tumours in elderly patients; Radiotherapie dans les tumeurs digestives chez le patient age

    Energy Technology Data Exchange (ETDEWEB)

    Guillerme, F.; Clavier, J.B.; Nehme-Schuster, H.; Schumacher, C.; Noel, G. [Centre de lutte contre le cancer Paul-Strauss, Strasbourg (France)

    2011-10-15

    The authors comment the taking into care of a digestive cancer in the case of elderly patient. These patients are treated by radiotherapy, operative radiotherapy with concomitant chemotherapy, or pre-operative radiotherapy, depending on the age, on the cancer type, with an adaptation of the total dose or with a hypo-fractionation of the treatment. Short communication

  19. Fractionated vs. single-fraction stereotactic radiotherapy in patients with vestibular schwannoma. Hearing preservation and patients' self-reported outcome based on an established questionnaire

    Energy Technology Data Exchange (ETDEWEB)

    Kessel, Kerstin A.; Fischer, Hanna; Vogel, Marco M.E.; Combs, Stephanie E. [Technical University of Munich (TUM), Department of Radiation Oncology, Munich (Germany); Helmholtz Zentrum Muenchen, Institute of Innovative Radiotherapy (iRT), Neuherberg (Germany); Oechsner, Markus [Technical University of Munich (TUM), Department of Radiation Oncology, Munich (Germany); Bier, Henning [Technical University of Munich (TUM), Department of Otorhinolaryngology, Munich (Germany); Meyer, Bernhard [Technical University of Munich (TUM), Department of Neurosurgery, Munich (Germany)

    2017-03-15

    Stereotactic radiotherapy (RT) has been established as a valid treatment alternative in patients with vestibular schwannoma (VS). There is ongoing controversy regarding the optimal fractionation. Hearing preservation may be the primary goal for patients with VS, followed by maintenance of quality of life (QoL). From 2002 to 2015, 184 patients with VS were treated with radiosurgery (RS) or fractionated stereotactic radiotherapy (FSRT). A survey on current symptoms and QoL was conducted between February and June 2016. Median follow-up after RT was 7.5 years (range 0-14.4 years). Mean overall survival (OS) after RT was 31.1 years, with 94 and 87% survival at 5 and 10 years, respectively. Mean progression-free survival (PFS) was 13.3 years, with 5- and 10-year PFS of 92%. Hearing could be preserved in RS patients for a median of 36.3 months (range 2.3-13.7 years). Hearing worsened in 17 (30%) cases. Median hearing preservation for FSRT was 48.7 months (range 0.0-13.8 years); 29 (23%) showed hearing deterioration. The difference in hearing preservation was not significant between RS and FSRT (p = 0.3). A total of 123/162 patients participated in the patient survey (return rate 76%). The results correlate well with the information documented in the patient files for tinnitus and facial and trigeminal nerve toxicity. Significant differences appeared regarding hearing impairment, gait uncertainty, and imbalance. These data confirm that RS and FSRT are comparable in terms of local control for VS. RS should be reserved for smaller lesions, while FSRT can be offered independently of tumor size. Patient self-reported outcome during follow-up is of high value. The established questionnaire could be validated in the independent cohort. (orig.) [German] Die stereotaktische Radiotherapie (RT) wurde als gueltige Behandlungsalternative bei Patienten mit Vestibularisschwannom (VS) etabliert. Diskussionen ueber die optimale Fraktionierung laufen jedoch. Der Erhalt von Hoervermoegen

  20. Bacterial density and community structure associated with aggregate size fractions of soil-feeding termite mounds.

    Science.gov (United States)

    Fall, S; Nazaret, S; Chotte, J L; Brauman, A

    2004-08-01

    The building and foraging activities of termites are known to modify soil characteristics such as the heterogeneity. In tropical savannas the impact of the activity of soil-feeding termites ( Cubitermes niokoloensis) has been shown to affect the properties of the soil at the aggregate level by creating new soil microenvironments (aggregate size fractions) [13]. These changes were investigated in greater depth by looking at the microbial density (AODC) and the genetic structure (automated rRNA intergenic spacer analysis: ARISA) of the communities in the different aggregate size fractions (i.e., coarse sand, fine sand, coarse silt, fine silt, and dispersible clays) separated from compartments (internal and external wall) of three Cubitermes niokoloensis mounds. The bacterial density of the mounds was significantly higher (1.5 to 3 times) than that of the surrounding soil. Within the aggregate size fractions, the termite building activity resulted in a significant increase in bacterial density within the coarser fractions (>20 mum). Multivariate analysis of the ARISA profiles revealed that the bacterial genetic structures of unfractionated soil and soil aggregate size fractions of the three mounds was noticeably different from the savanna soil used as a reference. Moreover, the microbial community associated with the different microenvironments in the three termite mounds revealed three distinct clusters formed by the aggregate size fractions of each mound. Except for the 2-20 mum fraction, these results suggest that the mound microbial genetic structure is more dependent upon microbial pool affiliation (the termite mound) than on the soil location (aggregate size fraction). The causes of the specificity of the microbial community structure of termite mound aggregate size fractions are discussed.

  1. Long term outcome of adolescent and adult patients with pineal parenchymal tumors treated with fractionated radiotherapy between 1982 and 2003 -- a single institution's experience

    International Nuclear Information System (INIS)

    Stoiber, Eva Maria; Schaible, Benjamin; Herfarth, Klaus; Schulz-Ertner, Daniela; Huber, Peter E; Debus, Jürgen; Oertel, Susanne

    2010-01-01

    To evaluate the effectivity of fractionated radiotherapy in adolescent and adult patients with pineal parenchymal tumors (PPT). Between 1982 and 2003, 14 patients with PPTs were treated with fractionated radiotherapy. 4 patients had a pineocytoma (PC), one a PPT with intermediate differentiation (PPTID) and 9 patients a pineoblastoma (PB), 2 of which were recurrences. All patients underwent radiotherapy on the primary tumor site with a median total dose of 54 Gy. In 9 patients with primary PB treatment included whole brain irradiation (3 patients) or irradiation of the craniospinal axis (6 patients) with a median total dose of 35 Gy. Median follow-up was 123 months in the PC patients and 109 months in the patients with primary PB. 7 patients were free from relapse at the end of follow-up. One PC patient died from spinal seeding. Among 5 PB patients treated with radiotherapy without chemotherapy, 3 developed local or spinal tumor recurrence. Both patients treated for PB recurrences died. The patient with PPTID is free of disease 7 years after radiotherapy. Local radiotherapy seems to be effective in patients with PC and some PPTIDs. Diagnosis and treatment of patients with more aggressive variants of PPTIDs as well as treatment of PB needs to be further improved, since local and spinal failure even despite craniospinal irradiation (CSI) is common. As PPT are very rare tumors, treatment within multi-institutional trials remains necessary

  2. Radiobiological aspects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation

    International Nuclear Information System (INIS)

    Turesson, I.

    1990-01-01

    The biological effects of continuous low dose-rate irradiation and fractionated high dose-rate irradiation in interstitial and intracavitary radiotherapy and total body irradiation are discussed in terms of dose-rate fractionation sensitivity for various tissues. A scaling between dose-rate and fraction size was established for acute and late normal-tissue effects which can serve as a guideline for local treatment in the range of dose rates between 0.02 and 0.005 Gy/min and fraction sizes between 8.5 and 2.5 Gy. This is valid provided cell-cycle progression and proliferation can be ignored. Assuming that the acute and late tissue responses are characterized by α/β values of about 10 and 3 Gy and a mono-exponential repair half-time of about 3 h, the same total doses given with either of the two methods are approximately equivalent. The equivalence for acute and late non-hemopoietic normal tissue damage is 0.02 Gy/min and 8.5 Gy per fraction; 0.01 Gy/min and 5.5 Gy per fraction; and 0.005 Gy/min and 2.5Gy per fraction. A very low dose rate, below 0.005 Gy/min, is thus necessary to simulate high dose-rate radiotherapy with fraction sizes of about 2Gy. The scaling factor is, however, dependent on the repair half-time of the tissue. A review of published data on dose-rate effects for normal tissue response showed a significantly stronger dose-rate dependence for late than for acute effects below 0.02 Gy/min. There was no significant difference in dose-rate dependence between various acute non-hemopoietic effects or between various late effects. The consistent dose-rate dependence, which justifies the use of a general scaling factor between fraction size and dose rate, contrasts with the wide range of values for repair half-time calculated for various normal-tissue effects. This indicates that the model currently used for repair kinetics is not satisfactory. There are also few experimental data in the clinical dose-rate range, below 0.02 Gy/min. It is therefore

  3. Uranium release from different size fractions of sediments in Hanford 300 area, Washington, USA

    International Nuclear Information System (INIS)

    Du Jiangkun; Bao Jianguo; Hu Qinhong; Ewing, Robert P.

    2012-01-01

    Stirred-flow cell tests were carried out to investigate uranium (U) release from different size fractions of sediments from the U.S. Department of Energy’s Hanford 300 Area in Washington, USA. Results show that the measured concentration of U release varies with different size fractions, with the fine-grained mass fractions (<75 μm, 75–500 μm, and 500–2000 μm) being the main U carriers. However, because the sediment is mainly composed of gravel (2000–8000 μm) materials, the gravel fraction is a non-negligible U pool. Our elution experiments give a value of 8.7% of the total U being in the gravel fraction, significantly reducing the current uncertainty in evaluating U inventory. A log–log plot of released U concentration vs. elution volume (i.e., elution time) shows a power-law relationship for all size fractions, with identical exponents for the three fine size fractions (−0.875). For the <2000 μm mass fraction, comparing our eluted U values with reported total U concentrations, we estimate that a lower bound value 8.6% of the total uranium is labile. This compares well with the previously published value of 11.8% labile U after extraction with a dilute extractant for three weeks. - Highlights: ► Stirred-flow cells were used to study U release in Hanford 300 Area sediment. ► Fine-grained size fractions have higher U concentrations. ► U in coarse fraction is less studied, but its 8.7–9.3% of total U is non-negligible. ► A power-law relationship is observed between released U and elution volume. ► About 8.6% of U in the <2 mm sediment is labile.

  4. Should carbogen and nicotinamide be given throughout the full course of fractionated radiotherapy regimens?

    International Nuclear Information System (INIS)

    Rojas, A.M.; Johns, H.; Fiat, P.R.

    1993-01-01

    Tumor radiosensitization with carbogen and nicotinamide (CON) was compared when both agents were given throughout fractionated radiotherapy with the sensitization observed when administered with only half of the fractions. The effect of overall treatment time on the local control of tumors irradiated in air or with CON was also investigated. Local tumor control of a rodent adenocarcinoma, CaNT, was studied using eight different 20-fraction x-ray regimens. An overall time of either 10 or 20 days was used and CON was given with all, the first half or last half of the treatment. Relative to air, all six sensitizer combinations gave a large and significant increase in sensitization (p much-lt 0.00001). Enhancement ratios were 1.9 and 2.1 when CON was given with all 20 fractions in either 10 or 20 days, respectively. For both overall times, enhancement ratios were reduced by 15-25% when CON was given with only half of the fractions. In air, reducing the treatment time from 20 to 10 days gave a small but significant decrease in the isoeffective doses. When CON was administered with either all or part of a schedule, varying the treatment time had little or no effect on local tumor control. No toxic side-effects were encountered when the sensitizers were administered 10 or 20 times, either once or twice per day. CON is an effective and non-toxic tumor radiosensitizer. In CaNT tumors, a significantly greater effect is seen when CON is given with every fraction of the schedule. The sensitizers reduced or abolished the sparing effect of overall time. 22 refs., 1 fig., 2 tabs

  5. Exclusive radiotherapy and concurrent endocrine therapy for the management of elderly breast cancer patients: Case study and review of hypo-fractionated schemes; Hormonoradiotherapie exclusive dans la prise en charge du cancer du sein de la personne agee: cas clinique et revue de la litterature des schemas hypofractionnes

    Energy Technology Data Exchange (ETDEWEB)

    Auberdiac, P.; Cartier, L.; Malkoun, N.; Chauleur, C.; De Laroche, G.; Magne, N. [Departement de radiotherapie, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France); Chargari, C. [Service d' oncologie radiotherapie, hopital d' instruction des armees du Val-de-Grace, 74, boulevard de Port-Royal, 75230 Paris cedex 5 (France); Melis, A.; Jacquin, J.P. [Departement d' oncologie medicale, institut de cancerologie de la Loire, 108 bis, avenue Albert-Raimond, BP 60008, 42271 Saint-Priest-en-Jarez cedex (France)

    2011-12-15

    Normo-fractionated radiotherapy is standard for adjuvant management of patients treated with breast conservative surgery for breast cancer. However, many elderly patients are not eligible to such strategy, either because of concurrent diseases, or because the tumor is inoperable. Several protocols of exclusive radiotherapy have been reported in the literature, frequently using hypo-fractionated radiotherapy and endocrine therapy. We report a case of a patient treated with exclusive endocrine and radiotherapy and address the state of the art on hypo-fractionated schemes for the management of elderly breast cancer patients. While hypo-fractionated radiotherapy does not compromise the oncologic or cosmetic outcome, there is no prospective data that assesses the place of radiotherapy for the exclusive treatment of elderly patients. This strategy should be further assessed in clinical randomized trial. (authors)

  6. An antiangiogenic agent (TNP-470) inhibited reoxygenation during fractionated radiotherapy of murine mammary carcinoma

    International Nuclear Information System (INIS)

    Murata, Rumi; Nishimura, Yasumasa; Hiraoka, Masahiro

    1997-01-01

    Purpose: TNP-470, a synthetic analogue of fumagillin which is a natural product of Aspergillus fumigatus, has been noted as an angiogenesis inhibitor. Combined effects of TNP-470 with fractionated radiotherapy (RT) were investigated using a mouse tumor. Methods and Materials: Tumors were early generations of mammary carcinoma in C3H/He mice. Treatments were initiated when tumors reached an average diameter of 4-5 mm. Tumor response was evaluated by tumor growth (TG) time assay and 50% tumor control dose (TCD 50 ) assay. Tumors were irradiated locally under hypoxic conditions or in air. Five fractionated radiation doses were given in the TG time assay, whereas a single dose or 10 fractionated doses were given in the TCD 50 assay. TNP-470 (100 mg/kg) was administered subcutaneously twice a week during and/or after RT. Results: In the TG time assay, significant delay of tumor growth was observed by TNP-470 alone (100 mg/kg x 2) compared with control tumors (p 50 assay, no significant difference in TCD 50 s was observed between RT alone and RT combined with TNP-470 in single dose experiments. Hypoxic fraction of tumors calculated from the TCD 50 s was not affected significantly by administrating TNP-470 24 h before RT. On the other hand, in 10-fraction experiments, the TCD 50 (RT with TNP-470, in air) was significantly higher than the TCD 50 (RT alone, in air) (p 50 (RT with TNP-470) and the TCD 50 (RT alone) under hypoxic conditions

  7. Successful treatment of tumor-induced osteomalacia due to an intracranial tumor by fractionated stereotactic radiotherapy.

    Science.gov (United States)

    Tarasova, Valentina D; Trepp-Carrasco, Alejandro G; Thompson, Robert; Recker, Robert R; Chong, William H; Collins, Michael T; Armas, Laura A G

    2013-11-01

    Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, characterized by tumor secretion of fibroblast growth factor-23 (FGF23) causing hypophosphatemia due to renal phosphate wasting. TIO is usually caused by small, benign, difficult-to-localize, mesenchymal tumors. Although surgery with wide excision of tumor borders is considered the "gold standard" for definitive therapy, it can be associated with considerable morbidity depending on the location. To date, radiation therapy has not been considered as an effective treatment modality in TIO. A 67-year-old female presented with multiple nontraumatic fractures, progressive bone pain, and muscle weakness for 4 years. She was found to have biochemical evidence of urinary phosphate wasting with low serum phosphorus, low-normal serum calcium, normal 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and high serum FGF23 levels. TIO was diagnosed. Selective venous sampling for FGF23 confirmed that a 1.7-cm left frontal mass, radiographically similar to a meningioma, was the causative tumor. She declined surgery due to fear of complications and instead underwent fractionated stereotactic radiotherapy for 6 weeks. In less than 4 years after radiation therapy, she was successfully weaned off phosphorus and calcitriol, starting from 2 g of oral phosphorus daily and 1 μg of calcitriol daily. Her symptoms have resolved, and she has not had any new fractures. Stereotactic radiotherapy was an effective treatment modality for TIO in our patient. Fractionated stereotactic radiation therapy represents an alternative to surgery for patients with TIO who are not surgical candidates or who decline surgery.

  8. Successful Treatment of Tumor-Induced Osteomalacia due to an Intracranial Tumor by Fractionated Stereotactic Radiotherapy

    Science.gov (United States)

    Trepp-Carrasco, Alejandro G.; Thompson, Robert; Recker, Robert R.; Chong, William H.; Collins, Michael T.

    2013-01-01

    Context: Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome, characterized by tumor secretion of fibroblast growth factor-23 (FGF23) causing hypophosphatemia due to renal phosphate wasting. TIO is usually caused by small, benign, difficult-to-localize, mesenchymal tumors. Although surgery with wide excision of tumor borders is considered the “gold standard” for definitive therapy, it can be associated with considerable morbidity depending on the location. To date, radiation therapy has not been considered as an effective treatment modality in TIO. Objective: A 67-year-old female presented with multiple nontraumatic fractures, progressive bone pain, and muscle weakness for 4 years. She was found to have biochemical evidence of urinary phosphate wasting with low serum phosphorus, low-normal serum calcium, normal 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, and high serum FGF23 levels. TIO was diagnosed. Selective venous sampling for FGF23 confirmed that a 1.7-cm left frontal mass, radiographically similar to a meningioma, was the causative tumor. She declined surgery due to fear of complications and instead underwent fractionated stereotactic radiotherapy for 6 weeks. Results: In less than 4 years after radiation therapy, she was successfully weaned off phosphorus and calcitriol, starting from 2 g of oral phosphorus daily and 1 μg of calcitriol daily. Her symptoms have resolved, and she has not had any new fractures. Conclusions: Stereotactic radiotherapy was an effective treatment modality for TIO in our patient. Fractionated stereotactic radiation therapy represents an alternative to surgery for patients with TIO who are not surgical candidates or who decline surgery. PMID:24014621

  9. Concept for quantifying the dose from image guided radiotherapy

    International Nuclear Information System (INIS)

    Schneider, Uwe; Hälg, Roger; Besserer, Jürgen

    2015-01-01

    Radiographic image guidance is routinely used for patient positioning in radiotherapy. All radiographic guidance techniques can give a significant radiation dose to the patient. The dose from diagnostic imaging is usually managed by using effective dose minimization. In contrast, image-guided radiotherapy adds the imaging dose to an already high level of therapeutic radiation which cannot be easily managed using effective dose. The purpose of this work is the development of a concept of IGRT dose quantification which allows a comparison of imaging dose with commonly accepted variations of therapeutic dose. It is assumed that dose variations of the treatment beam which are accepted in the spirit of the ALARA convention can also be applied to the additional imaging dose. Therefore we propose three dose categories: Category I: The imaging dose is lower than a 2 % variation of the therapy dose. Category II: The imaging dose is larger than in category I, but lower than the therapy dose variations between different treatment techniques. Category III: The imaging dose is larger than in Category II. For various treatment techniques dose measurements are used to define the dose categories. The imaging devices were categorized according to the measured dose. Planar kV-kV imaging is a category I imaging procedure. kV-MV imaging is located at the edge between category I and II and is for increasing fraction size safely a category I imaging technique. MV-MV imaging is for all imaging technologies a category II procedure. MV fan beam CT for localization is a category I technology. Low dose protocols for kV CBCT are located between category I and II and are for increasing fraction size a category I imaging technique. All other investigated Pelvis-CBCT protocols are category II procedures. Fan beam CT scout views are category I technology. Live imaging modalities are category III for conventional fractionation, but category II for stereotactic treatments. Dose from radiotherapy

  10. Intervals between multiple fractions per day

    International Nuclear Information System (INIS)

    Fowler, J.F.

    1988-01-01

    Assuming the linear quadratic model for dose-response curves enables the proportion of repairable damage to be calculated for any size of dose per fraction. It is given by the beta (dose squared) term, and represents a larger proportion of the total damage for larger doses per fraction, but also for late-reacting than for early-reacting tissues. For example at 2 Gy per fraction, repairable damage could represent nearly half the total damage in late-reacting tissues but only one fifth in early-reacting tissues. Even if repair occurs at the same rate in both tissues, it will obviously take longer for 50% of the damage to fade to an undetectable level (3 or 5%) than for 20% to do so. This means that late reactions require longer intervals than early reactions when multiple fraction per day radiotherapy is planned, even if the half-lives of repair are not different. (orig.)

  11. Pain relief and quality of life following radiotherapy for bone metastases: a randomised trial of two fractionation schedules

    International Nuclear Information System (INIS)

    Gaze, Mark N.; Kelly, Charles G.; Kerr, Gillian R.; Cull, Ann; Cowie, Valerie J.; Gregor, Anna; Howard, Grahame C.W.; Rodger, Alan

    1997-01-01

    Background: The optimum dose and fractionation schedule for the palliative irradiation of painful bone metastases is controversial. Purpose: To compare the efficacy, side-effects and effect on quality of life of two commonly used radiotherapy schedules in the management of painful bone metastases. Materials and methods: In a prospective trial, 280 patients were randomised to receive either a single 10 Gy treatment or a course of 22.5 Gy in five daily fractions for the relief of localised metastatic bone pain. Results: Response rates have been calculated from 240 assessable treated sites of pain. The overall response rates were 83.7% (single treatment) and 89.2% (five fractions). The complete response rates were 38.8% (single treatment) and 42.3% (five fractions). The median duration of pain control was 13.5 weeks (single treatment) and 14.0 weeks (five fractions). None of these differences was statistically significant. There were no differences between the groups in the effect of treatment on a variety of quality of life parameters. Conclusions: It is concluded that a single 10 Gy treatment is as effective as a course of 22.5 Gy in five fractions in the management of painful bone metastases

  12. Geometric accuracy of field alignment in fractionated stereotactic conformal radiotherapy of brain tumors

    International Nuclear Information System (INIS)

    Kortmann, Rolf D.; Becker, Gerd; Perelmouter, Jury; Buchgeister, Markus; Meisner, Christoph; Bamberg, Michael

    1999-01-01

    Purpose: To assess the accuracy of field alignment in patients undergoing three-dimensional (3D) conformal radiotherapy of brain tumors, and to evaluate the impact on the definition of planning target volume and control procedures. Methods and Materials: Geometric accuracy was analyzed in 20 patients undergoing fractionated stereotactic conformal radiotherapy for brain tumors. Rigid head fixation was achieved by using cast material. Transfer of stereotactic coordinates was performed by an external positioning device. The accuracy during treatment planning was quantitatively assessed by using repeated computed tomography (CT) examinations in treatment position (reproducibility of isocenter). Linear discrepancies were measured between treatment plan and CT examination. In addition, for each patient, a series of 20 verifications were taken in orthogonal projections. Linear discrepancies were measured between first and all subsequent verifications (accuracy during treatment delivery). Results: For the total group of patients, the distribution of deviations during treatment setup showed mean values between -0.3-1.2 mm, with standard deviations (SD) of 1.3-2.0 mm. During treatment delivery, the distribution of deviations revealed mean values between 0.7-0.8 mm, with SDs of 0.5-0.6 mm, respectively. For all patients, deviations for the transition to the treatment machine were similar to deviations during subsequent treatment delivery, with 95% of all absolute deviations between less than 2.8 and 4.6 mm. Conclusion: Random fluctuations of field displacements during treatment planning and delivery prevail. Therefore, our quantitative data should be considered when prescribing the safety margins of the planning target volume. Repeated CT examination are useful to detect operator errors and large random or systematic deviations before start of treatment. Control procedures during treatment delivery appear to be of limited importance. In addition, our findings should help to

  13. Clinical experience with a new stereotactic localisation method for fractionated radiotherapy of extracranial lesions

    International Nuclear Information System (INIS)

    Engenhart-Cabillic, R.; Pastyr, O.; Wenz, F.; Debus, J.; Schlegel, W.; Bahner, M.L.; Wannenmacher, M.

    1996-01-01

    Purpose/Objective: Effectiveness of radiotherapy in terms of local control has been shown to be linked with treatment accuracy. Conformal radiation therapy outside the brain maybe limited by relative inaccuracy of positioning and repositioning uncertainty during treatment planning, simulation and radiotherapy. It has been shown that stereotactic localisation methods provide an excellent localisation accuracy for intracranial lesions. The aim of this study was to develop a stereotactic system for the whole body and to test the feasibility in a clinical study. Materials and Method: The system includes a reversible stereotactic patient fixation, localization and positioning system which can be used during CT-imaging for simulation and for treatment. The target volume and adjacent critical structures were outlined for treatment three dimensional planning and the coordinates of the target point were calculated. The overall accuracy of target localization including soft and hardware inaccuracy was measured by a phantom. Three patients with spinal and paraspinal tumors were treated by conventionally fractionated high precision megavoltage radiotherapy with this system. The treatment time was 6 weeks in each patients. The stereotactic coordinates of anatomical landmarks as well as implanted fiducals were measured by CT-imaging, X-ray localization and electronic portal imaging at 20 different paraspinal localisations. Stereotactic CT-imaging was performed for treatment planning and once a week during treatment. Results: Standard deviation of stereotactic coordinats in the phantom was 0.5 mm in the lateral direction (x), 1.0 mm in the cranio-caudal orientation (z) and 1.2 mm in the dorso-ventral orientation. About 60 minutes are required to immobilise the patient properly for the first set-up and the subsequent daily set-up time during therapy was 10 min. In patients a total of 18 CT examination and 56 portal images have been analysed. The mean variation of the stereotactic

  14. Clinical outcomes of a phase I/II study of 48 Gy of stereotactic body radiotherapy in 4 fractions for primary lung cancer using a stereotactic body frame

    International Nuclear Information System (INIS)

    Nagata, Yasushi; Takayama, Kenji; Matsuo, Yukinori; Norihisa, Yoshiki; Mizowaki, Takashi; Sakamoto, Takashi; Sakamoto, Masato; Mitsumori, Michihide; Shibuya, Keiko; Araki, Norio; Yano, Shinsuke; Hiraoka, Masahiro

    2005-01-01

    Purpose: To evaluate the clinical outcomes of 48 Gy of three-dimensional stereotactic radiotherapy in four fractions for treating Stage I lung cancer using a stereotactic body frame. Methods and Materials: Forty-five patients who were treated between September 1998 and February 2004 were included in this study. Thirty-two patients had Stage IA lung cancer, and the other 13 had Stage IB lung cancer where tumor size was less than 4 cm in diameter. Three-dimensional treatment planning using 6-10 noncoplanar beams was performed to maintain the target dose homogeneity and to decrease the irradiated lung volume >20 Gy. All patients were irradiated using a stereotactic body frame and received four single 12 Gy high doses of radiation at the isocenter over 5-13 (median = 12) days. Results: Seven tumors (16%) completely disappeared after treatment (CR) and 38 tumors (84%) decreased in size by 30% or more (PR). Therefore, all tumors showed local response. During the follow-up of 6-71 (median = 30) months, no pulmonary complications greater than an National Cancer Institute-Common Toxicity Criteria of Grade 3 were noted. No other vascular, cardiac, esophageal, or neurologic toxicities were encountered. Forty-four (98%) of 45 tumors were locally controlled during the follow-up period. However, regional recurrences and distant metastases occurred in 3 and 5 of T1 patients and zero and 4 of T2 patients, respectively. For Stage IA lung cancer, the disease-free survival and overall survival rates after 1 and 3 years were 80% and 72%, and 92% and 83%, respectively, whereas for Stage IB lung cancer, the disease-free survival and overall survival rates were 92% and 71%, and 82% and 72%, respectively. Conclusion: Forty-eight Gy of 3D stereotactic radiotherapy in 4 fractions using a stereotactic body frame is useful for the treatment of Stage I lung tumors

  15. A prospective and randomized study of radiotherapy, sequential chemotherapy radiotherapy and concomitant chemo therapy-radiotherapy in unresectable non small cell carcinoma of the lung

    Directory of Open Access Journals (Sweden)

    Dasgupta Anirban

    2006-01-01

    Full Text Available Purpose: Treatment of advanced Non small cell lung cancer (NSCLC often produces dismal results. Combination of available treatment modalities has reportedly improved the outcome. A prospectively randomized trial was conducted, comparing combined treatment modalities versus radiotherapy alone, in treatment of unresectable NSCLC. Materials and Methods: A total of 103 patients were randomized to three groups. In group ′A′, 32 patients received radiotherapy alone (6500 cGy/30 fraction. In group ′B′, 35 patients received neoadjuvant chemotherapy (Cisplatin 80 mg/m2 on day 1 and Etoposide 100 mg/m day 1-3 intravenously q3 weeks for 3 cycles, followed by radiotherapy (6000 cGy/30 fractions and 3 more cycles of Chemotherapy, with the same regimen. In group ′C′, 36 patients received radiotherapy (5000 cGy/25 fractions with concurrent chemotherapy (ciplatin 20 mg/m2 + Etoposide 75 mg/m2 intravenously on day 1-5 and day 22-26, followed by 2 more cycles of chemotherapy,q3 weeks with the same regimen. Results: Initial treatment responses were significantly higher in group ′B′ ( P P Conclusion: Addition of chemotherapy with radiation in unresectable NSCLC improves response rates, time to tumour progression and disease free survival, though the same effect is not translated in overall survival.

  16. Radiotherapy for breast cancer and pacemaker

    International Nuclear Information System (INIS)

    Menard, J.; Campana, F.; Bollet, M.A.; Dendale, R.; Fournier-Bidoz, N.; Marchand, V.; Mazal, A.; Fourquet, A.; Kirova, Y.M.; Kirov, K.M.; Esteve, M.

    2011-01-01

    Purpose. - Patients with permanent cardiac pacemakers occasionally require radiotherapy. Therapeutic Irradiation may cause pacemakers to malfunction due to the effects of ionizing radiation or electromagnetic interference. We studied the breast cancer patients who needed breast and/or chest wall and lymph node irradiation to assess the feasibility and tolerance in this population of patients. Patients and methods. - From November 2008 to December 2009, more than 900 patients received radiotherapy for their breast cancer in our department using megavoltage linear accelerator (X 4-6 MV and electrons). Among them, seven patients were with permanent pacemaker. All patients have been treated to the breast and chest wall and/or lymph nodes. Total dose to breast and/or chest wall was 50 Gy/25 fractions and 46 Gy/23 fractions to lymph nodes. Patients who underwent conserving surgery followed by breast irradiation were boosted when indicated to tumour bed with 16 Gy/8 fractions. All patients were monitored everyday in presence of radiation oncologist to follow the function of their pacemaker. All pacemakers were controlled before and after radiotherapy by the patients' cardiologist. Results. - Seven patients were referred in our department for postoperative breast cancer radiotherapy. Among them, only one patient was declined for radiotherapy and underwent mastectomy without radiotherapy. In four cases the pacemaker was repositioned before the beginning of radiotherapy. Six patients, aged between 48 and 84 years underwent irradiation for their breast cancer. Four patients were treated with conserving surgery followed by breast radiotherapy and two with mastectomy followed by chest wall and internal mammary chain, supra- and infra-clavicular lymph node irradiation. The dose to the pacemaker generator was kept below 2 Gy. There was no pacemaker dysfunction observed during the radiotherapy. Conclusion. - The multidisciplinary work with position change of the pacemaker before

  17. Mineralogical variation in the size fractions of a Ranong kaolin, southern Thailand

    Science.gov (United States)

    Pisutha-Arnond, Visut; Phuvichit, Suraphol; Leepowpanth, Quanchai

    A representative crude Ranong kaolin from the Thungkla-Ranong mine was separated into > 2 mm (granule), 2-1 mm (very coarse sand), 1-0.5 mm (coarse sand), 0.5-0.25 mm (medium sand), 0.25-0.125 mm (fine sand), 0.125-0.062 mm (very fine sand) and 62-28, 28-14, 17-7, 7-4, 4-2, 2-1 and dispersive X-ray spectrometer (EDX). Kaolin group minerals were differentiated by using XRD in combination with various chemical and heat treatments together with TEM, SEM and DTA. The Ranong kaolin consists predominantly of tubular halloysite, poorly crystallized kaolinite and quartz with minor amounts of mica and K-feldspars. Other trace constituents include gibbsite, tourmaline, zircon and colored impurities (i.e. extractable iron hydroxide coating on clay mineral surface). The kaolin minerals are found in all size fractions by which their contents and halloysite/kaolinite ratios increase as the particle sizes become finer. Quartz and mica are also detected in almost all size fractions. They are, however, more abundant with coarsening particle size. Gibbsite, K-feldspar and tourmaline are mainly concentrated in the fine sand to silt size fractions. Crystallinity of kaolin minerals as measured by XRD varied moderately with size. Relatively pure kaolin minerals, predominantly halloysite and kaolinite, can be obtained in the particle size below 1 or 2 μm.

  18. 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...... for simultaneous or integrated external beam radiotherapy and imaging, e.g., using computed tomography (CT)....

  19. A new concept of radiotherapy: space fractionation in proton therapy; Un nuevo concepto en radioterapia: fraccionamiento espacial en terapia con protones

    Energy Technology Data Exchange (ETDEWEB)

    Prezado Alonso, Y.; Fois, G.

    2013-07-01

    In recent years several experiments with animals have shown that the combination of small field sizes and a spatial neighborhood of the dose of radiation therapy with synchrotron radiation techniques lead to a significant increase of the dose of tolerance of healthy tissues. The aim of this study is to evaluate the feasibility of a new form of radiotherapy: radiotherapy with proton minibeams. (Author)

  20. Postmastectomy radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Shikama, Naoto; Koguchi, Masahiko; Sasaki, Shigeru; Kaneko, Tomoki; Shinoda, Atsunori; Nishikawa, Atsushi [Shinshu Univ., Matsumoto, Nagano (Japan). School of Medicine

    2000-10-01

    Since there have been few reports on postmastectomy radiotherapy having a high evidence level in Japan, the significance of postoperative radiotherapy and the irradiation techniques were reviewed based on reports from Western countries. Authors focused on the indications for postoperative irradiation, irradiation methods (irradiation sites, irradiation techniques; prosthetics, methods of irradiating the chest wall and lymph nodes, timing of irradiation), and complications, and discuss them. The factors thought to be adaptable to postmastectomy radiotherapy have been listed. Axillary lymph node metastasis and the size of the primary focus are thought to be important factors in locoregional recurrence. The chest wall and the supraclavicular lymph nodes are the usual sites of irradiation after mastectomy. The irradiation method consists of tangential irradiation of the chest wall and single-field irradiation of the supraclavicular lymph nodes, with 46-50 Gy in fractional doses of 1.8-2 Gy x 5/w is administered for 4.5-5.5 weeks. The timing of irradiation in the West is generally after chemotherapy. Adverse radiation effects include ischemic heart disease, pneumonitis, arm edema, rib fractures, and brachial plexus paralysis. The frequency of these complications is increased by the combined use of chemotherapy or surgery. The breast cancer cure rate in Japan is generally better than in the West. It remains to be determined whether the clinical data from Europe and America are applicable to the treatment of breast cancer in Japan. To address this issue, a clinical investigation should be performed in Japan with close cooperation between surgeons, physicians, pathologists, and radiotherapists. (K.H.)

  1. Measurement of void fraction and bubble size distribution in two-phase flow system

    International Nuclear Information System (INIS)

    Huahun, G.

    1987-01-01

    The importance of study two phase flow parameter and microstructure has appeared increasingly, with the development of two-phase flow discipline. In the paper, the measurement methods of several important microstructure parameter in a two phase flow vertical channel have been studied. Using conductance probe the two phase flow pattern and the average void fraction have been measured previously by the authors. This paper concerns microstructure of the bubble size distribution and local void fraction. The authors studied the methods of measuring bubble velocity, size distribution and local void fraction using double conductance probes and a set of apparatus. Based on our experiments and Yoshihiro work, a formula of calculated local void fraction has been deduced by using the statistical characteristics of bubbles in two phase flow and the relation between calculated bubble size and voltage has been determined. Finally the authors checked by using photograph and fast valve, which is classical but reliable. The results are the same with what has been studied before

  2. Cosmetic results following lumpectomy axillary dissection and radiotherapy for smaal breast cancers

    International Nuclear Information System (INIS)

    Dewar, J.A.; Benhamou, S.; Benhamou, E.; Arriagada, R.; Petit, J.Y.; Fontaine, F.; Sarrazin, D.

    1988-01-01

    Between 1970 and April 1982, 592 women, with T/sub 1/, small T/sub 2/, N/sub 0/, N/sub 1/, M/sub 0/ breast cancer were managed by lumpectomy, axillary dissection and radiotherapy at the Institut Gustave Roussy (IGR). The overall cosmetic result and the degree of assymetry, fibrosis and telangiectasia of the treated breast were assessed by the radiation oncologist at each follow-up visit. The changes in these cosmetic parameters with time are shown. At 5 years the overall cosmetic result was excellent in 58%, good in 38% and fair or poor in 8%. A multivariate analysis was performed of the factors associated with a cosmetic defect. The most significant factors were tumour size, the presence of defect after surgery and the daily applied dose per fraction to the breast. Surgical and radiotherapy technique (especially alternate day fractionation) can significantly affect the cosmetic result obtained

  3. Germline glutathione S-transferase variants in breast cancer: Relation to diagnosis and cutaneous long-term adverse effects after two fractionation patterns of radiotherapy

    International Nuclear Information System (INIS)

    Edvardsen, Hege; Kristensen, Vessela N.; Grenaker Alnaes, Grethe Irene B.Sc.; Bohn, Mona; Erikstein, Bjorn; Helland, Aslaug; Borresen-Dale, Anne-Lise; Fossa, Sophie Dorothea

    2007-01-01

    Purpose: To explore whether certain glutathione S-transferase (GST) polymorphisms are associated with an increased risk of breast cancer or the level of radiation-induced adverse effects after two fractionation patterns of adjuvant radiotherapy. Methods and Materials: The prevalence of germline polymorphic variants in GSTM1, GSTP1, and GSTT1 was determined in 272 breast cancer patients and compared with that in a control group of 270 women from the general population with no known history of breast cancer. The genetic variants were determined using multiplex polymerase chain reaction followed by restriction enzyme fragment analysis. In 253 of the patients surveyed for radiotherapy-induced side effects after a median observation time of 13.7 years (range, 7-22.8 years), the genotypes were related to the long-term effects observed after two fractionation patterns (treatment A, 4.3 Gy in 10 fractions for 156 patients; and treatment B, 2.5 Gy in 20 fractions for 97; both administered within a 5-week period). Results: None of the GST polymorphisms conferred an increased risk of breast cancer, either alone or in combination. Compared with treatment B, treatment A was followed by an increased level of moderate to severe radiation-induced side effects for all the endpoints studied (i.e., degree of telangiectasia, subcutaneous fibrosis and atrophy, lung fibrosis, costal fractures, and pleural thickening; p <0.001 for all endpoints). A significant association was found between the level of pleural thickening and the GSTP1 Ile105Val variant. Conclusion: The results of this study have illustrated the impact of hypofractionation on the level of adverse effects and indicated that the specific alleles of GSTP1, M1, and T1 studied here may be significant in determining the level of adverse effects after radiotherapy

  4. The role of particle-size soil fractions in the adsorption of heavy metals

    Science.gov (United States)

    Mandzhieva, Saglara; Minkina, Tatiana; Pinsky, David; Batukaev, Abdulmalik; Kalinitchenko, Valeriy; Sushkova, Svetlana; Chaplygin, Viktor; Dikaev, Zaurbek; Startsev, Viktor; Bakoev, Serojdin

    2014-05-01

    Ion-exchange adsorption phenomena are important in the immobilization of heavy metals (HMs) by soils. Numerous works are devoted to the study of this problem. However, the interaction features of different particle-size soil fractions and their role in the immobilization of HMs studied insufficiently. Therefore, the assessment of the effect of the particle-size distribution on the adsorption properties of soils is a vital task. The parameters of Cu2+, Pb2+ and Zn2+ adsorption by chernozems of the south of Russia and their particle-size fractions were studied. In the particle-size fractions separated from the soils, the concentrations of Cu2+, Pb2+, and Zn2 decreased with the decreasing particle size. The parameters of the adsorption values of k (the constant of the affinity)and Cmax.(the maximum adsorption of the HMs) characterizing the adsorption of HMs by the southern chernozem and its particle-size fractions formed the following sequence: silt > clay > entire soil. The adsorption capacity of chernozems for Cu2+, Pb2+, and Zn2+ depending on the particle-size distribution decreased in the following sequence: clay loamy ordinary chernozem clay loamy southern chernozem> loamy southern chernozem> loamy sandy southern chernozem. According to the parameters of the adsorption by the different particle-size fractions, the heavy metal cations form a sequence analogous to that obtained for the entire soils: Cu2+ ≥ Pb2+ > Zn2+. The parameters of the heavy metal adsorption by similar particle-size fractions separated from different soils decreased in the following order: clay loamy chernozem> loamy chernozem> loamy sandy chernozem. The analysis of the changes in the parameters of the Cu2+, Pb2+, and Zn2+ adsorption by the studied soils and their particle-size fractions showed that the extensive adsorption characteristic - the maximum adsorption (Cmax.) - is a less sensitive parameter characterizing the adsorption capacity of the soils than the intensive characteristic of

  5. A feasibility study: Selection of a personalized radiotherapy fractionation schedule using spatiotemporal optimization

    International Nuclear Information System (INIS)

    Kim, Minsun; Stewart, Robert D.; Phillips, Mark H.

    2015-01-01

    Purpose: To investigate the impact of using spatiotemporal optimization, i.e., intensity-modulated spatial optimization followed by fractionation schedule optimization, to select the patient-specific fractionation schedule that maximizes the tumor biologically equivalent dose (BED) under dose constraints for multiple organs-at-risk (OARs). Methods: Spatiotemporal optimization was applied to a variety of lung tumors in a phantom geometry using a range of tumor sizes and locations. The optimal fractionation schedule for a patient using the linear-quadratic cell survival model depends on the tumor and OAR sensitivity to fraction size (α/β), the effective tumor doubling time (T d ), and the size and location of tumor target relative to one or more OARs (dose distribution). The authors used a spatiotemporal optimization method to identify the optimal number of fractions N that maximizes the 3D tumor BED distribution for 16 lung phantom cases. The selection of the optimal fractionation schedule used equivalent (30-fraction) OAR constraints for the heart (D mean ≤ 45 Gy), lungs (D mean ≤ 20 Gy), cord (D max ≤ 45 Gy), esophagus (D max ≤ 63 Gy), and unspecified tissues (D 05 ≤ 60 Gy). To assess plan quality, the authors compared the minimum, mean, maximum, and D 95 of tumor BED, as well as the equivalent uniform dose (EUD) for optimized plans to conventional intensity-modulated radiation therapy plans prescribing 60 Gy in 30 fractions. A sensitivity analysis was performed to assess the effects of T d (3–100 days), tumor lag-time (T k = 0–10 days), and the size of tumors on optimal fractionation schedule. Results: Using an α/β ratio of 10 Gy, the average values of tumor max, min, mean BED, and D 95 were up to 19%, 21%, 20%, and 19% larger than those from conventional prescription, depending on T d and T k used. Tumor EUD was up to 17% larger than the conventional prescription. For fast proliferating tumors with T d less than 10 days, there was no

  6. Fractionated stereotactic radiotherapy in brain tumors and cervical region. Experience of the Dean Funes Medical Center, first experience in stereotactic radiotherapy and radiosurgery inside the country

    International Nuclear Information System (INIS)

    Castro Vita, H.; Brunetto, M.; Derechinsky, V; Derechinsky, G.; Derechinsky, M.; Gonzalez, S.; Marinello, A.

    2004-01-01

    Purpose: A retrospective study to analyze the results of 53 patients treated with stereotactic radiotherapy in 'Centro Medico Dean Funes' was performed. The patients had brain and head and neck tumors. Patients and methods: From November 1997 to March 2003, 53 patients were treated with stereotactic radiotherapy in 'Centro Medico Dean Funes'. The daily dose administered varied from 1.8 to 2 Gy and the total dose from 30 to 70 Gy. The minimal follow up was 2 months, and the medium follow up 32 months. Local control and survival were analyzed in all patients, as well as tolerance and the complications of the treatment. Results: Since these series represented a very heterogeneous group of patients, the final results were very difficult to compare with other alternative treatments. However, an excellent tolerance to therapy was observed. Some subsets of patients had good results to treatment: patients with metastasis to the orbit, patients with lesions to the sellar and parasellar regions and some who relapsed following conventional radiotherapy, mainly lymphomas. Conclusions: Stereotactic radiotherapy is a valid therapeutic method to treat tumors of the brain and head and neck, as long as the tumor has a moderate size (6 cm. or less) and the shape is cylindrical or ellipsoid. Stereotactic radiation improves the therapeutic ratio as compared with the conventional radiotherapy. It has advantages over the 3D technique, and could compete with IMRT (Intensity modulated radiation therapy). (author) [es

  7. Investigation of magnetic active core sizes and hydrodynamic diameters of a magnetically fractionated ferrofluid

    International Nuclear Information System (INIS)

    Büttner, Markus; Weber, Peter; Schmidl, Frank; Seidel, Paul; Röder, Michael; Schnabelrauch, Matthias; Wagner, Kerstin; Görnert, Peter; Glöckl, Gunnar; Weitschies, Werner

    2011-01-01

    In this work we address the question which relates between the size of the magnetically active core of magnetic nanoparticles (MNPs) and the size of the overall particle in the solution (the so-called hydrodynamic diameter d hyd ) exists. For this purpose we use two methods of examination that can deliver conclusions about the properties of MNP which are not accessible with normal microscopy. On the one hand, we use temperature dependent magnetorelaxation (TMRX) method, which enables direct access to the energy barrier distribution and by using additional hysteresis loop measurements can provide details about the size of the magnetically active cores. On the other hand, to determine the size of the overall particle in the solution, we use the magnetooptical relaxation of ferrofluids (MORFF) method, where the stimulation is done magnetically while the reading of the relaxation signal, however, is done optically. As a basis for the examinations in this work we use a ferrofluid that was developed for medicinal purposes and which has been fractioned magnetically to obtain differently sized fractions of MNPs. The two values obtained through these methods for each fraction shows the success in fractioning the original solution. Therefore, one can conclude a direct correlation between the size of the magnetically active core and the size of the complete particle in the solution from the experimental results. To calculate the size of the magnetically active core we found a temperature dependent anisotropy constant which was taken into account for the calculations. Furthermore, we found relaxation signals at 18 K for all fractions in these TMRX measurements, which have their origin in other magnetic effects than the Néel relaxation.

  8. Spinal Cord Doses in Palliative Lung Radiotherapy Schedules

    International Nuclear Information System (INIS)

    Ffrrcsi, F.H.; Parton, C.

    2006-01-01

    Aim: We aim to check the safety of the standard palliative radiotherapy techniques by using the Linear quadratic model for a careful estimation of the doses received by the spinal cord, in all standard palliative lung radiotherapy fields and fractionation. Material and Methods: All patients surveyed at this prospective audit were treated with palliative chest radio-therapy for lung cancer over a period from January to June 2005 by different clinical oncology specialists within the department. Radiotherapy field criteria were recorded and compared with the recommended limits of the MRC trial protocols for the dose and fractionation prescribed. Doses delivered to structures off the field central axis were estimated using a standard CT scan of the chest. Dose estimates were made using an SLPLAN planning system. As unexpected spinal cord toxicity has been reported after hypo fractionated chest radiotherapy, a sagittal view was used to calculate the isodoses along the length of the spinal cord that could lie within the RT field. Equivalent dose estimates are made using the Linear Quadratic Equivalent Dose formula (LQED). The relative radiation sensitivity of spinal cord for myelopathy (the a/b dose) cord has been estimated as a/b = 1 Gy. Results: 17 Gy in 2 fraction and 39 Gy in 13 fraction protocols have spinal cord equivalent doses (using the linear-quadratic model) that lie within the conventional safe limits of 50 Gy in 25 fractions for the 100% isodose. However when the dosimetry is modelled for a 6 MV 100 cm isocentric linac in 3 dimensions, and altered separations and air space inhomogeneity are considered, the D-Max doses consistently fall above this limit on our 3 model patients. Conclusion: The 17 Gy in 2 fraction and 39 Gy in 13 fraction protocol would risk spinal cord damage if the radio therapist was unaware of the potential spinal cord doses. Alterative doses are suggested below 15.5 Gy/ 2 fractions (7 days apart) would be most acceptable

  9. The role of precautionary radiotherapy of the neck in NO laryngeal cancers

    International Nuclear Information System (INIS)

    Baroncelli, G.; Bonetti, B.; La Face, B.; Moretti, R.

    1988-01-01

    The role of precautionary radiotherapy of the neck in laryngeal cancers (exept T1-T2 glottic and some T1 supraglottic cancers) NO at the clinical staging was investigated. Two-hundred and fifty-three patients were examined: 143 were irradiated only on T, and 110 also on the neck. Radiotherapy of the neck in the latter group was performed either by means of two large opposed fields of photon beams including T and N, or by means of fields of photon beams on T and electron beams (8x12 cm 2 average) on the neck, to quite exclude any risks for the spinal cord. The dose was 45-50 Gy (2 Gy/fraction/day; 5 fraction/week) in 4-5 weeks. A comparison of the results obtained in the two groups, in terms of survival-rate and relapse-free time, indicates that radiotherapy reduces the change of relapses on N (6.1% vs. 14.62% at 3 years; p=0.04) and improves the patient's survival chances (82.5% vs. 68.4% at 3 years; and 80.8% vs. 63.4% at 5 years). Our data were then compared with literature data on the importance of N field size in radiation treatment. As a rule, some authors enlarge the field to be treated to a total nodal neck irradiation, but their results are not significally different from those we obtained with 8x12 cm 2 field size

  10. Nelson's syndrome: single centre experience using the linear accelerator (LINAC) for stereotactic radiosurgery and fractionated stereotactic radiotherapy.

    Science.gov (United States)

    Wilson, Peter J; Williams, Janet R; Smee, Robert I

    2014-09-01

    Nelson's syndrome is a unique clinical phenomenon of growth of a pituitary adenoma following bilateral adrenalectomies for the control of Cushing's disease. Primary management is surgical, with limited effective medical therapies available. We report our own institution's series of this pathology managed with radiation: prior to 1990, 12 patients were managed with conventional radiotherapy, and between 1990 and 2007, five patients underwent stereotactic radiosurgery (SRS) and two patients fractionated stereotactic radiotherapy (FSRT), both using the linear accelerator (LINAC). Tumour control was equivocal, with two of the five SRS patients having a reduction in tumour volume, one patient remaining unchanged, and two patients having an increase in volume. In the FSRT group, one patient had a decrease in tumour volume whilst the other had an increase in volume. Treatment related morbidity was low. Nelson's syndrome is a challenging clinical scenario, with a highly variable response to radiation in our series. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Single-fraction stereotactic radiotherapy: a dose-response analysis of arteriovenous malformation obliteration

    International Nuclear Information System (INIS)

    Touboul, Emmanuel; Al Halabi, Assem; Buffat, Laurent; Merienne, Louis; Huart, Judith; Schlienger, Michel; Lefkopoulos, Dimitrios; Mammar, Hamid; Missir, Odile; Meder, Jean-Francois; Laurent, Alex; Housset, Martin

    1998-01-01

    Purpose: Stereotactic radiotherapy delivered in a high-dose single fraction is an effective technique to obliterate intracranial arteriovenous malformations (AVM). To attempt to analyze the relationships between dose, volume, and obliteration rates, we studied a group of patients treated using single-isocenter treatment plans. Methods and Materials: From May 1986 to December 1989, 100 consecutive patients with angiographically proven AVM had stereotactic radiotherapy delivered as a high-dose single fraction using a single-isocenter technique. Distribution according to Spetzler-Martin grade was as follows: 79 grade 1-3, three grade 4, 0 grade 5, and 18 grade 6. The target volume was spheroid in 74 cases, ellipsoid in 11, and large and irregular in 15. The targeted volume of the nidus was estimated using two-dimensional stereotactic angiographic data and, calculated as an ovoid-shaped lesion, was 1900 ± 230 mm 3 (median 968 mm 3 ; range 62-11, 250 mm 3 ). The mean minimum target dose (D min ) was 19 ± 0.6 Gy (median 20 Gy; range: 3-31.5). The mean volume within the isodose which corresponded to the minimum target dose was 2500 ± 300 mm 3 (median 1200 mm 3 ; range 75-14 900 mm 3 ). The mean maximum dose (D max ) was 34.5 ± 0.5 Gy (median 35 Gy; range 15-45). The mean angiographic follow-up was 42 ± 2.3 months (median 37.5; range 7-117). Results: The absolute obliteration rate was 51%. The 5-year actuarial obliteration rate was 62.5 ± 7%. After univariate analysis, AVM obliteration was influenced by previous surgery (p = 0.0007), D min by steps of 5 Gy (p = 0.005), targeted volume of the nidus (≤968 mm 3 vs. >968 mm 3 ; p = 0.015), and grade according to Spetzler-Martin (grade 1-3 vs. grade 4-6; p = 0.011). After multivariate analysis, the independent factors influencing AVM obliteration were the D min [relative risk (RR) 1.9; 95% confidence interval (CI) 1.4-2.5; p min but does not seem to be influenced by D max and the targeted volume of the nidus

  12. Fractionation and delivery schedules in combined radiotherapy-cisplatin for head and neck cancer

    International Nuclear Information System (INIS)

    Marcu, L.; Van Doorn, T.; Royal Adelaide Hospital,; Olver, I.

    2000-01-01

    Full text: Since Rosenberg's initial discovery, cisplatin has become one of the most effective anticancer drugs, with particular significance in head and neck cancer. For advanced disease, where the tumour is unresectable, radiotherapy and chemotherapy, either singularly or combined, remain the possible therapeutic modalities. The majority of the trials using a combination of cisplatin and radiation obtained much better results than the single-agent trials. But the best schedule, dosage and timing between radiation and drug administration are still unknown. Many positive steps were however made to eliminate the cisplatin-produced side effects, as much as possible. The tendency in current trials is to fractionate the drug dose by daily administration and also to hyperfractionate the radiation. In this way the long-term benefits are improved and the toxicity is better tolerated

  13. Metagenomic analysis of size-fractionated picoplankton in a marine oxygen minimum zone

    OpenAIRE

    Ganesh, Sangita; Parris, Darren J; DeLong, Edward F; Stewart, Frank J

    2013-01-01

    Marine oxygen minimum zones (OMZs) support diverse microbial communities with roles in major elemental cycles. It is unclear how the taxonomic composition and metabolism of OMZ microorganisms vary between particle-associated and free-living size fractions. We used amplicon (16S rRNA gene) and shotgun metagenome sequencing to compare microbial communities from large (>1.6 μm) and small (0.2–1.6 μm) filter size fractions along a depth gradient in the OMZ off Chile. Despite steep vertical redox ...

  14. DISTRIBUTION OF METALS IN PARTICLE SIZE FRACTIONS IN SOILS OF TWO FORESTED CATENAS (SMOLENSK-MOSCOW UPLAND

    Directory of Open Access Journals (Sweden)

    Olga Samonova

    2013-01-01

    Full Text Available The concentrations and distribution of Fe, Ti, Zr, Mn, Cu. Ni, Co, Cr, Pb, and Zn associated with various particle size fractions have been analyzed in soils of two forested catenas located in the middle Protva River basin on the Smolensk-Moscow Upland. The results showed that concentration of metals in a particular size fraction was defined by a complex of factors: element chemical properties, soil type, genesis of a soil horizon, and position in the catena. A clearly defined relationship between the fraction size and metal concentrations was found for Ti and Zr. The highest levels of Ti were found in coarse and medium silt, while Zr had its highest values only in coarse silt and, in some cases, in fine sand. Such metals as Fe, Mn, Co, Cu and Pb had high concentrations in sand, fine silt, and clay fractions depending on a soil type and a genetic horizon. The maximum load of Cr, Zn, and Ni (in the majority of cases was found in clay fraction. The minimum loads of Fe, Mn, Co, Cu, and Ni were found in the coarse silt fraction. Variation in concentrations of heavy metals differed depending on particle size. For most metals, the variations were decreasing from coarser to finer fractions.Key words: soils, heavy metals, grain-size fractionation, vertical and lateral distribution patterns

  15. Low-dose prophylactic craniospinal radiotherapy for intracranial germinoma

    International Nuclear Information System (INIS)

    Schoenfeld, Gordon O.; Amdur, Robert J.; Schmalfuss, Ilona M.; Morris, Christopher G.; Keole, Sameer R.; Mendenhall, William M.; Marcus, Robert B.

    2006-01-01

    Purpose: To report outcomes of patients with localized intracranial germinoma treated with low-dose craniospinal irradiation (CSI) followed by a boost to the ventricular system and primary site. Methods and Materials: Thirty-one patients had pathologically confirmed intracranial germinoma and no spine metastases. Low-dose CSI was administered in 29 patients: usually 21 Gy of CSI, 9.0 Gy of ventricular boost, and a 19.5-Gy tumor boost, all at 1.5 Gy per fraction. Our neuroradiologist recorded three-dimensional tumor size on magnetic resonance images before, during, and after radiotherapy. Results: With a median follow-up of 7.0 years, 29 of 31 patients (94%) are disease free. One failure had nongerminomatous histology; the initial diagnosis was a sampling error. Of 3 patients who did not receive CSI, 1 died. No patient developed myelopathy, visual deficits, dementia, or skeletal growth problems. In locally controlled patients, tumor response according to magnetic resonance scan was nearly complete within 6 months after radiotherapy. Conclusions: Radiotherapy alone with low-dose prophylactic CSI cures almost all patients with localized intracranial germinoma. Complications are rare when the daily dose of radiotherapy is limited to 1.5 Gy and the total CSI dose to 21 Gy. Patients without a near-complete response to radiotherapy should undergo resection to rule out a nongerminomatous element

  16. Randomised phase I/II study to evaluate carbon ion radiotherapy versus fractionated stereotactic radiotherapy in patients with recurrent or progressive gliomas: The CINDERELLA trial

    International Nuclear Information System (INIS)

    Combs, Stephanie E; Wick, Wolfgang; Debus, Jürgen; Burkholder, Iris; Edler, Lutz; Rieken, Stefan; Habermehl, Daniel; Jäkel, Oliver; Haberer, Thomas; Haselmann, Renate; Unterberg, Andreas

    2010-01-01

    Treatment of patients with recurrent glioma includes neurosurgical resection, chemotherapy, or radiation therapy. In most cases, a full course of radiotherapy has been applied after primary diagnosis, therefore application of re-irradiation has to be applied cauteously. With modern precision photon techniques such as fractionated stereotactic radiotherapy (FSRT), a second course of radiotherapy is safe and effective and leads to survival times of 22, 16 and 8 months for recurrent WHO grade II, III and IV gliomas. Carbon ions offer physical and biological characteristics. Due to their inverted dose profile and the high local dose deposition within the Bragg peak precise dose application and sparing of normal tissue is possible. Moreover, in comparison to photons, carbon ions offer an increased relative biological effectiveness (RBE), which can be calculated between 2 and 5 depending on the GBM cell line as well as the endpoint analyzed. Protons, however, offer an RBE which is comparable to photons. First Japanese Data on the evaluation of carbon ion radiation therapy for the treatment of primary high-grade gliomas showed promising results in a small and heterogeneous patient collective. In the current Phase I/II-CINDERELLA-trial re-irradiation using carbon ions will be compared to FSRT applied to the area of contrast enhancement representing high-grade tumor areas in patients with recurrent gliomas. Within the Phase I Part of the trial, the Recommended Dose (RD) of carbon ion radiotherapy will be determined in a dose escalation scheme. In the subsequent randomized Phase II part, the RD will be evaluated in the experimental arm, compared to the standard arm, FSRT with a total dose of 36 Gy in single doses of 2 Gy. Primary endpoint of the Phase I part is toxicity. Primary endpoint of the randomized part II is survival after re-irradiation at 12 months, secondary endpoint is progression-free survival. The Cinderella trial is the first study to evaluate carbon ion

  17. Patients' preference for radiotherapy fractionation schedule in the palliation of symptomatic unresectable lung cancer

    International Nuclear Information System (INIS)

    Tang, J. I.; Lu, J. J.; Wong, L. C.

    2008-01-01

    Full text: The palliative radiotherapeutic management of unresectable non-small-cell lung cancer is controversial, with various fractionation (F x) schedules available. We aimed to determine patient's choice of F x schedule after involvement in a decision-making process using a decision board. A decision board outlining the various advantages and disadvantages apparent in the Medical Research Council study of F x schedules (17 Gy in two fractions vs 39 Gy in 13 fractions) was discussed with patients who met Medical Research Council eligibility criteria. Patients were then asked to indicate their preferred F x schedules, reasons and their level of satisfaction with being involved in the decision making process. Radiation oncologists (R O ) could prescribe radiotherapy schedules irrespective of patients' preferences. Of 92 patients enrolled, 55% chose the longer schedule. English-speaking patients were significantly more likely to choose the longer schedule (P 0.02, 95% confidence interval: 1.2-7.6). Longer F x was chosen because of longer survival (90%) and better local control (12%). Shorter F x was chosen for shorter overall treatment duration (80%), cost (61%) and better symptom control (20%). In all, 56% of patients choosing the shorter schedule had their treatment altered by the treating R O , whereas only 4% of patients choosing longer F x had their treatment altered (P O 's own biases.

  18. Radiotherapy for Vestibular Schwannomas: A Critical Review

    International Nuclear Information System (INIS)

    Murphy, Erin S.; Suh, John H.

    2011-01-01

    Vestibular schwannomas are slow-growing tumors of the myelin-forming cells that cover cranial nerve VIII. The treatment options for patients with vestibular schwannoma include active observation, surgical management, and radiotherapy. However, the optimal treatment choice remains controversial. We have reviewed the available data and summarized the radiotherapeutic options, including single-session stereotactic radiosurgery, fractionated conventional radiotherapy, fractionated stereotactic radiotherapy, and proton beam therapy. The comparisons of the various radiotherapy modalities have been based on single-institution experiences, which have shown excellent tumor control rates of 91-100%. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy have successfully improved cranial nerve V and VII preservation to >95%. The mixed data regarding the ideal hearing preservation therapy, inherent biases in patient selection, and differences in outcome analysis have made the comparison across radiotherapeutic modalities difficult. Early experience using proton therapy for vestibular schwannoma treatment demonstrated local control rates of 84-100% but disappointing hearing preservation rates of 33-42%. Efforts to improve radiotherapy delivery will focus on refined dosimetry with the goal of reducing the dose to the critical structures. As future randomized trials are unlikely, we suggest regimented pre- and post-treatment assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.

  19. A feasibility study: Selection of a personalized radiotherapy fractionation schedule using spatiotemporal optimization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minsun, E-mail: mk688@uw.edu; Stewart, Robert D. [Department of Radiation Oncology, University of Washington, Seattle, Washington 98195-6043 (United States); Phillips, Mark H. [Departments of Radiation Oncology and Neurological Surgery, University of Washington, Seattle, Washington 98195-6043 (United States)

    2015-11-15

    Purpose: To investigate the impact of using spatiotemporal optimization, i.e., intensity-modulated spatial optimization followed by fractionation schedule optimization, to select the patient-specific fractionation schedule that maximizes the tumor biologically equivalent dose (BED) under dose constraints for multiple organs-at-risk (OARs). Methods: Spatiotemporal optimization was applied to a variety of lung tumors in a phantom geometry using a range of tumor sizes and locations. The optimal fractionation schedule for a patient using the linear-quadratic cell survival model depends on the tumor and OAR sensitivity to fraction size (α/β), the effective tumor doubling time (T{sub d}), and the size and location of tumor target relative to one or more OARs (dose distribution). The authors used a spatiotemporal optimization method to identify the optimal number of fractions N that maximizes the 3D tumor BED distribution for 16 lung phantom cases. The selection of the optimal fractionation schedule used equivalent (30-fraction) OAR constraints for the heart (D{sub mean} ≤ 45 Gy), lungs (D{sub mean} ≤ 20 Gy), cord (D{sub max} ≤ 45 Gy), esophagus (D{sub max} ≤ 63 Gy), and unspecified tissues (D{sub 05} ≤ 60 Gy). To assess plan quality, the authors compared the minimum, mean, maximum, and D{sub 95} of tumor BED, as well as the equivalent uniform dose (EUD) for optimized plans to conventional intensity-modulated radiation therapy plans prescribing 60 Gy in 30 fractions. A sensitivity analysis was performed to assess the effects of T{sub d} (3–100 days), tumor lag-time (T{sub k} = 0–10 days), and the size of tumors on optimal fractionation schedule. Results: Using an α/β ratio of 10 Gy, the average values of tumor max, min, mean BED, and D{sub 95} were up to 19%, 21%, 20%, and 19% larger than those from conventional prescription, depending on T{sub d} and T{sub k} used. Tumor EUD was up to 17% larger than the conventional prescription. For fast proliferating

  20. Carbon storage in soil size fractions under two cacao agroforestry systems in Bahia, Brazil.

    Science.gov (United States)

    Gama-Rodrigues, Emanuela F; Ramachandran Nair, P K; Nair, Vimala D; Gama-Rodrigues, Antonio C; Baligar, Virupax C; Machado, Regina C R

    2010-02-01

    Shaded perennial agroforestry systems contain relatively high quantities of soil carbon (C) resulting from continuous deposition of plant residues; however, the extent to which the C is sequestered in soil will depend on the extent of physical protection of soil organic C (SOC). The main objective of this study was to characterize SOC storage in relation to soil fraction-size classes in cacao (Theobroma cacao L.) agroforestry systems (AFSs). Two shaded cacao systems and an adjacent natural forest in reddish-yellow Oxisols in Bahia, Brazil were selected. Soil samples were collected from four depth classes to 1 m depth and separated by wet-sieving into three fraction-size classes (>250 microm, 250-53 microm, and <53 microm)-corresponding to macroaggregate, microaggregate, and silt-and-clay size fractions-and analyzed for C content. The total SOC stock did not vary among systems (mean: 302 Mg/ha). On average, 72% of SOC was in macroaggregate-size, 20% in microaggregate-size, and 8% in silt-and-clay size fractions in soil. Sonication of aggregates showed that occlusion of C in soil aggregates could be a major mechanism of C protection in these soils. Considering the low level of soil disturbances in cacao AFSs, the C contained in the macroaggregate fraction might become stabilized in the soil. The study shows the role of cacao AFSs in mitigating greenhouse gas (GHG) emission through accumulation and retention of high amounts of organic C in the soils and suggests the potential benefit of this environmental service to the nearly 6 million cacao farmers worldwide.

  1. Hypo-fractionated radiotherapy in the treatment of breast cancer in elderly patients; Radiotherapie hypofractionnee dans le traitement du cancer du sein de la personne agee

    Energy Technology Data Exchange (ETDEWEB)

    Merikhi, T.; Meziane, A.; Laarit, I.; Bali, M.S.; Bendjazia-Djemaa, A. [CHU de Constantine, Constantine (Algeria)

    2011-10-15

    The authors report an assessment on the long term of the efficiency and toxicity of a hypo-fractionated radiotherapy scheme: 5 Gy on d1 and d3, 6,5 Gy on d15 and d17, and 5 Gy on d29 and d31. The study is based on 144 patients treated between 1990 and 2007. Results are presented in terms of average follow-up, of survival rate without relapse by 5 and 8 years. This treatment could be a good solution to reduce therapeutic delays and a good response to expectations of elderly patients suffering from breast cancer. Short communication

  2. Hypo-fractionated radiotherapy of breast cancer: long term results of a set of 80 cases treated in the radiotherapy department of the Oran university hospital; Radiotherapie hypofractionnee dans le cancer du sein: resultats a long terme d'une serie de 80 cas traites dans le service de radiotherapie du centre hospitalier universitaire d'Oran

    Energy Technology Data Exchange (ETDEWEB)

    Boukerche, A.; Yahia, A.; Madouri, R.; Belmiloud, H.; Dali-Youcef, A.F. [Service de radiotherapie, CHU d' Oran, Oran (Algeria)

    2011-10-15

    The authors report the assessment of the local and locoregional control and of the acute and late toxicity of adjuvant hypo-fractionated radiotherapy in breast cancer treatment. During 1998, 80 women have been treated by conservative or radical surgery and hypo-fractionated tele-cobalto-therapy (36 Gy in five fractions of 3 Gy a week, and a boost of 15 Gy in five fractions in case of conservative surgery). Results are discussed in terms of local and locoregional recurrence, tolerance, late toxicity, global survival, and tumour classification. The irradiation scheme seems perfectly achievable but a greater number of patients and a longer follow-up are required to better assess the efficiency and aesthetic results. Short communication

  3. Probability dynamics of a repopulating tumor in case of fractionated external radiotherapy.

    Science.gov (United States)

    Stavreva, Nadia; Stavrev, Pavel; Fallone, B Gino

    2009-12-01

    In this work two analytical methods are developed for computing the probability distribution of the number of surviving cells of a repopulating tumor during a fractionated external radio-treatment. Both methods are developed for the case of pure birth processes. They both allow the description of the tumor dynamics in case of cell radiosensitivity changing in time and for treatment schedules with variable dose per fraction and variable time intervals between fractions. The first method is based on a direct solution of the set of differential equations describing the tumor dynamics. The second method is based on the works of Hanin et al. [Hanin LG, Zaider M, Yakovlev AY. Distribution of the number of clonogens surviving fractionated radiotherapy: a long-standing problem revisited. Int J Radiat Biol 2001;77:205-13; Hanin LG. Iterated birth and death process as a model of radiation cell survival. Math Biosci 2001;169:89-107; Hanin LG. A stochastic model of tumor response to fractionated radiation: limit theorems and rate of convergence. Math Biosci 2004;191:1-17], where probability generating functions are used. In addition a Monte Carlo algorithm for simulating the probability distributions is developed for the same treatment conditions as for the analytical methods. The probability distributions predicted by the three methods are compared graphically for a certain set of values of the model parameters and an excellent agreement is found to exist between all three results, thus proving the correct implementation of the methods. However, numerical difficulties have been encountered with both analytical methods depending on the values of the model parameters. Therefore, the Poisson approximation is also studied and it is compared to the exact methods for several different combinations of the model parameter values. It is concluded that the Poisson approximation works sufficiently well only for slowly repopulating tumors and a low cell survival probability and that it

  4. The role of neck surgery in patients with primary oropharyngeal cancer treated by radiotherapy

    International Nuclear Information System (INIS)

    Peters, Lester J.; Weber, Randal S.; Morrison, William H.; Byers, Robert M.; Garden, Adam S.; Goepfert, Helmuth

    1996-01-01

    Purpose: The role of neck surgery in node- positive patients whose primary tumours are treated by definitive radiotherapy is controversial. A planned neck dissection following radiotherapy is frequently recommended regardless of response of the neck nodes to treatment. This analysis was undertaken to assess the risk of withholding planned neck dissection in patients who obtain a complete nodal response to irradiation. Materials and Methods: The analysis is based on all 100 patients treated using the concomitant boost protocol described below who presented between 1984 and 1993 with primary squamous cell carcinomas of the oropharynx and clinically positive cervical lymphadenopathy. There were 73 males and 27 females with a median age of 59. Primary disease site was base of tongue 39, tonsil 40, soft palate 14 and pharyngeal wall 7. Nodal stages were N1: 35, N2: 51 and N3: 15. Nodal size varied from 1 - 9 cm with a median of 3 cm. Radiotherapy consisted of 54 Gy in 30 fractions over 6 weeks to large fields with a boost to gross disease of 18 Gy in 12 fractions being delivered as a second daily fraction during the last 2.4 weeks of treatment. Seventy-five patients had their nodal disease treated definitively by radiotherapy; those who had complete clinical resolution of all nodal disease (62) had no planned surgery, while the remaining 13 underwent neck dissection for presumed residual disease. Twenty-five patients had either node excision (8) or neck dissection (17) prior to radiotherapy. Results: There were 8 cases of isolated neck failure of which 3 occurred in the 62 patients who had no planned neck surgery, 0 in the 13 patients who were operated for presumed residual disease (pathologically negative in 7) and 5 in the 25 patients who had initial neck surgery. Of the 62 patients who had a complete response to radiotherapy, the two year probability of neck control was 87% if the initial nodal size was ≤ 3 cm versus 85% for nodes > 3 cm. However the likelihood of

  5. SU-E-T-427: Cell Surviving Fractions Derived From Tumor-Volume Variation During Radiotherapy for Non-Small Cell Lung Cancer: Comparison with Predictive Assays

    Energy Technology Data Exchange (ETDEWEB)

    Chvetsov, A; Schwartz, J; Mayr, N [University of Washington, Seattle, WA (United States); Yartsev, S [London Health Sciences Centre, London, Ontario (Canada)

    2014-06-01

    Purpose: To show that a distribution of cell surviving fractions S{sub 2} in a heterogeneous group of patients can be derived from tumor-volume variation curves during radiotherapy for non-small cell lung cancer. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage (MV) computed tomography (CT). Statistical distributions of cell surviving fractions S{sup 2} and cell clearance half-lives of lethally damaged cells T1/2 have been reconstructed in each patient group by using a version of the two-level cell population tumor response model and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Non-small cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractions S{sub 2} for non-small cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S{sup 2} reconstructed from tumor volume variation agree with the PDF measured in vitro. Comparison of the reconstructed cell surviving fractions with patient survival data shows that the patient survival time decreases as the cell surviving fraction increases. Conclusion: The data obtained in this work suggests that the cell surviving fractions S{sub 2} can be reconstructed from the tumor volume

  6. SU-E-T-427: Cell Surviving Fractions Derived From Tumor-Volume Variation During Radiotherapy for Non-Small Cell Lung Cancer: Comparison with Predictive Assays

    International Nuclear Information System (INIS)

    Chvetsov, A; Schwartz, J; Mayr, N; Yartsev, S

    2014-01-01

    Purpose: To show that a distribution of cell surviving fractions S 2 in a heterogeneous group of patients can be derived from tumor-volume variation curves during radiotherapy for non-small cell lung cancer. Methods: Our analysis was based on two data sets of tumor-volume variation curves for heterogeneous groups of 17 patients treated for nonsmall cell lung cancer with conventional dose fractionation. The data sets were obtained previously at two independent institutions by using megavoltage (MV) computed tomography (CT). Statistical distributions of cell surviving fractions S 2 and cell clearance half-lives of lethally damaged cells T1/2 have been reconstructed in each patient group by using a version of the two-level cell population tumor response model and a simulated annealing algorithm. The reconstructed statistical distributions of the cell surviving fractions have been compared to the distributions measured using predictive assays in vitro. Results: Non-small cell lung cancer presents certain difficulties for modeling surviving fractions using tumor-volume variation curves because of relatively large fractional hypoxic volume, low gradient of tumor-volume response, and possible uncertainties due to breathing motion. Despite these difficulties, cell surviving fractions S 2 for non-small cell lung cancer derived from tumor-volume variation measured at different institutions have similar probability density functions (PDFs) with mean values of 0.30 and 0.43 and standard deviations of 0.13 and 0.18, respectively. The PDFs for cell surviving fractions S 2 reconstructed from tumor volume variation agree with the PDF measured in vitro. Comparison of the reconstructed cell surviving fractions with patient survival data shows that the patient survival time decreases as the cell surviving fraction increases. Conclusion: The data obtained in this work suggests that the cell surviving fractions S 2 can be reconstructed from the tumor volume variation curves measured

  7. Radiotherapy for bone metastases - Practice in Norway 1997 - 2007. A national registry-based study

    Energy Technology Data Exchange (ETDEWEB)

    Sande Laugsand, Tonje [European Palliative Care Research Centre (PRC), Faculty of Medicine, Norwegian Univ. of Technology and Science (NTNU), Trondheim (Norway)], e-mail: tonje.laugsand@ntnu.no; Kaasa, Stein; Lund, Jo-Aasmund [European Palliative Care Research Centre (PRC), Faculty of Medicine, Norwegian Univ. of Technology and Science (NTNU), Trondheim (Norway); Cancer Clinic, St. Olavs Hospital, Univ. Hospital of Trondheim, Trondheim (Norway); Romundstad, Paal [Dept. of Public Health, Faculty of Medicine, Norwegian Univ. of Technology and Science (NTNU), Trondheim (Norway); Johannesen, Tom Boerge [Cancer Registry of Norway, Oslo (Norway)

    2013-08-15

    Numerous randomised clinical trials have shown that the efficacy of single fraction radiotherapy for metastatic bone pain corresponds to that of multiple fractions of radiotherapy for the majority of patients. It is not clear to which extent single fraction radiotherapy has been implemented into clinical practice. Material and methods: A Norwegian national registry based study was conducted, including all radiotherapy schedules of 8 Gy x 1 and 3 Gy x 10 delivered to bone metastases in 1997 - 2007. Binomial regression analyses were used to study whether treatment centre, primary diagnosis, anatomical region irradiated, age, sex, and travel distance, were associated with the choice of fractionation. Results: A total of 14 380 radiotherapy episodes were identified. During the period 31% of the treatments were delivered as 8 Gy x 1. The proportion of single fraction treatments increased from 16% in 1997 to 41% in 2007. There were substantial differences in the proportion of single fraction treatments between the treatment centres (range 25 - 54%). These differences persisted after adjustment for sex, age, primary diagnosis, anatomical region, and travel distance. Conclusions: The study demonstrates an under utilisation of single fraction treatment for bone metastases in Norway during the study period.

  8. X-ray diffraction and thermal analysis of kaolins particle size fractions

    Directory of Open Access Journals (Sweden)

    Patricia dos Santos

    2013-09-01

    Full Text Available Kaolins are common geological materials and have high concentrations of kaolinite as well as the clay fraction of tropical and subtropical soils of Brazil. The characterization of kaolin is a proxy of assessing the contribution of kaolinite to important soil chemical and mineralogical attributes. This study evaluated four kaolins (commercial kaolin A (CCA, commercial kaolin B (CCB, pink sandy kaolin A (CRA and green sandy kaolin A (CVA in the original form and after particle size separation into: sand (200-53 mm, coarse silt (53-20 m, fine silt (20-2 m, large clay (2-1m, medium clay (1-0.5 m and fine clay (<0.5m fractions. The minerals were identified by X-ray diffraction (XRD and evaluated for crystallinity (kaolinite and halloysite through indexes Hughes and Brown, Amigó, Bramão and the dehydroxylation temperature. The physical fractionation was efficient to concentrate minerals in specific size fractions which were not identified in the original material. In CCA kaolin was concentrated one mineral which remains unidentified in fine fractions, in kaolin CRA, zircon was concentrated in the coarse silt and different silicates in the fine fractions, in kaolin CCB were concentrated kaolinite and a silicate in the medium and coarse clay fractions. The estimate by X-ray diffraction overestimated the amount of kaolinite and halloysite underestimated when compared to quantification by thermal gravimetric analysis The crystallinity index exhibit different behaviors depending on the mineralogy of each material, thus the correlation between the crystallinity of kaolinite and / or halloysite and other variables, may be compromised, especially in materials with distinct geological origins.

  9. Monitoring of tumor microcirculation during fractionated radiotherapy in patients with rectal carcinomas: a clinical study using contrast enhanced MR imaging

    International Nuclear Information System (INIS)

    Vries, A. de; Judmaier, W.; Griebel, J.; Kremser, Ch.; Gneiting, T.; Peer, S.; Aichner, F.; Lukas, P.

    1996-01-01

    Purpose/Objective: Combined radio chemotherapy is a frequently used treatment scheme for malignant neoplasms. The purpose of using chemotherapeutics such as 5-FU during radiotherapy is to enhance the effectiveness of radiation. The effectiveness of this approach depends on the accumulation of the drugs within the tumor, which is governed by micro circulatory parameters. However, to date scheduling of chemotherapy application is based on empirical data. There is no clinical study available monitoring tumor microcirculation during fractionated radiotherapy. Contrast enhanced MR imaging in tumors provides not only a better understanding of tumor micro vascularity but is also a method to characterize the substance accumulation within the tumor matrix during radiotherapy. This could help to optimize the scheduling of chemotherapy application. Materials and Methods: Patients with clinical and histological proven rectal carcinoma underwent a preoperative combined radio chemotherapy up to a total dose of 39,4Gy, hyperfractionated with b.i.d., single dose 1,1Gy. The fields in box-technique included the rectal canal and adjacent lymph nodes. 5-FU (300mg/m 2 per treatment day) was given continuously parallel to irradiation. To evaluate the Gd-DTPA (Magnevist, Schering, Germany) concentration time curve after i.v. constant rate infusion (0,05 mmol/kg Gd-DTPA) we used an ultrafast T1-mapping sequence on a 1,5-T whole body imager (Magneton Vision, Siemens, Germany). The transaxial slice (thickness 5 mm) was chosen so that both tumor and arterial vessels could be clearly identified. Before, during and after the infusion 53 T1 maps were obtained within 40 min in intervals of 14s (35 scans) and 120s (15 scans). Assuming a linear relation between relaxation rate, R1=1/T1, and Gd-DTPA concentration, concentration time curves were evaluated for arterial blood and tumor. The patients underwent MR imaging before and in constant intervals during fractionated radiotherapy. As a first

  10. Efficacy of ondansetron in the management of radiotherapy induced emesis: a review

    International Nuclear Information System (INIS)

    Levy, E.; Paillarse, J.M.; Votan, B.

    1994-01-01

    Radiotherapy-induced emesis depends on the site of irradiation, the field size and the dose per fraction and is generally less intense than chemotherapy-induced emesis. Established anti-emetic drugs offer only limited symptom control (50%). Ondansetron, a 5HT 3 receptors antagonist, had proven a complete or a major control efficacy (0-2 emetic episodes) of 68 to 95% in three pilot studies (fractionated, single-dose and total body irradiations). In controlled studies, ondansetron efficacy was significantly higher than placebo, metoclopramide and prochlorperazine. The treatment was well tolerated in the different studies. (authors). 23 refs., 2 figs., 1 tab

  11. Molecular diversity patterns among various phytoplankton size-fractions in West Greenland in late summer

    Science.gov (United States)

    Elferink, Stephanie; Neuhaus, Stefan; Wohlrab, Sylke; Toebe, Kerstin; Voß, Daniela; Gottschling, Marc; Lundholm, Nina; Krock, Bernd; Koch, Boris P.; Zielinski, Oliver; Cembella, Allan; John, Uwe

    2017-03-01

    Arctic regions have experienced pronounced biological and biophysical transformations as a result of global change processes over the last several decades. Current hypotheses propose an elevated impact of those environmental changes on the biodiversity, community composition and metabolic processes of species. The effects on ecosystem function and services, particularly when invasive or toxigenic harmful species become dominant, can be expressed over a wide range of temporal and spatial scales in plankton communities. Our study focused on the comparison of molecular biodiversity of three size-fractions (micro-, nano-, picoplankton) in the coastal pelagic zone of West Greenland and their association with environmental parameters. Molecular diversity was assessed via parallel amplicon sequencing the 28S rRNA hypervariable D1/D2 region. We showed that biodiversity distribution within the area of Uummannaq Fjord, Vaigat Strait and Disko Bay differed markedly within and among size-fractions. In general, we observed a higher diversity within the picoplankton size fraction compared to the nano- and microplankton. In multidimensional scaling analysis, community composition of all three size fractions correlated with cell size, silicate and phosphate, chlorophyll a (chl a) and dinophysistoxin (DTX). Individually, each size fraction community composition also correlated with other different environmental parameters, i.e. temperature and nitrate. We observed a more homogeneous community of the picoplankton across all stations compared to the larger size classes, despite different prevailing environmental conditions of the sampling areas. This suggests that habitat niche occupation for larger-celled species may lead to higher functional trait plasticity expressed as an enhanced range of phenotypes, whereas smaller organisms may compensate for lower potential plasticity with higher diversity. The presence of recently identified toxigenic harmful algal bloom (HAB) species (such

  12. Stable Carbon Fractionation In Size Segregated Aerosol Particles Produced By Controlled Biomass Burning

    Science.gov (United States)

    Masalaite, Agne; Garbaras, Andrius; Garbariene, Inga; Ceburnis, Darius; Martuzevicius, Dainius; Puida, Egidijus; Kvietkus, Kestutis; Remeikis, Vidmantas

    2014-05-01

    Biomass burning is the largest source of primary fine fraction carbonaceous particles and the second largest source of trace gases in the global atmosphere with a strong effect not only on the regional scale but also in areas distant from the source . Many studies have often assumed no significant carbon isotope fractionation occurring between black carbon and the original vegetation during combustion. However, other studies suggested that stable carbon isotope ratios of char or BC may not reliably reflect carbon isotopic signatures of the source vegetation. Overall, the apparently conflicting results throughout the literature regarding the observed fractionation suggest that combustion conditions may be responsible for the observed effects. The purpose of the present study was to gather more quantitative information on carbonaceous aerosols produced in controlled biomass burning, thereby having a potential impact on interpreting ambient atmospheric observations. Seven different biomass fuel types were burned under controlled conditions to determine the effect of the biomass type on the emitted particulate matter mass and stable carbon isotope composition of bulk and size segregated particles. Size segregated aerosol particles were collected using the total suspended particle (TSP) sampler and a micro-orifice uniform deposit impactor (MOUDI). The results demonstrated that particle emissions were dominated by the submicron particles in all biomass types. However, significant differences in emissions of submicron particles and their dominant sizes were found between different biomass fuels. The largest negative fractionation was obtained for the wood pellet fuel type while the largest positive isotopic fractionation was observed during the buckwheat shells combustion. The carbon isotope composition of MOUDI samples compared very well with isotope composition of TSP samples indicating consistency of the results. The measurements of the stable carbon isotope ratio in

  13. Hypo fractionated conformal irradiation of patients with malignant glioma

    International Nuclear Information System (INIS)

    Aboziada, M.A.; Abo-Kresha, A.E.

    2012-01-01

    Purpose: The aim of the study is to evaluate the effect of a conformal irradiation in short fractionation scheme of 49.5 Gy in 15 fractions in an overall time of 3 weeks, in terms of overall survival (OAS) and progression free survival (PFS) rates in brain glioma patients. Patients and methods: A prospective study was conducted on 54 brain glioma patients and was carried out in the Radiation Oncology Department, South Egypt Cancer Institute, Assiut University during the period from April 2006 till June 2009. Patients were treated by hypo fractionated conformal irradiation (49.5 Gy/15 fractions/3 weeks). Results: The median follow up was 23 months (range: 9-39 months). Two-year OAS and PFS rates were 68% and 60%, respectively. In univariate analysis, age > 50 years, poor performance status [Karnofasky score of >40- 50 years and glioblastoma pathology were the only independent prognostic factors that were associated with poor OAS (p = 0.003 and p = 0.004, respectively), and PFS (p = 0.027 and p = 0.011, respectively). Conclusion: Hypo fractionated conformal radiotherapy was as effective as the conventional radiotherapy, with time sparing for patients, and for radiation oncology centers. Hypo fractionated radiotherapy may be considered the radiotherapy regimen of choice in clinical practice for patients with gliomas

  14. Outcomes of Risk-Adapted Fractionated Stereotactic Radiotherapy for Stage I Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Lagerwaard, Frank J.; Haasbeek, Cornelis J.A.; Smit, Egbert F.; Slotman, Ben J.; Senan, S.

    2008-01-01

    Purpose: High local control rates can be achieved using stereotactic radiotherapy in Stage I non-small-cell lung cancer (NSCLC), but reports have suggested that toxicity may be of concern. We evaluated early clinical outcomes of 'risk-adapted' fractionation schemes in patients treated in a single institution. Methods and Materials: Of 206 patients with Stage I NSCLC, 81% were unfit to undergo surgery and the rest refused surgery. Pathologic confirmation of malignancy was obtained in 31% of patients. All other patients had new or growing 18F-fluorodeoxyglucose positron emission tomography positive lesions with radiologic characteristics of malignancy. Planning four-dimensional computed tomography scans were performed and fractionation schemes used (3 x 20 Gy, 5 x 12 Gy, and 8 x 7.5 Gy) were determined by T stage and risk of normal tissue toxicity. Results: Median overall survival was 34 months, with 1- and 2-year survivals of 81% and 64%, respectively. Disease-free survival (DFS) at 1 and 2 years was 83% and 68%, respectively, and DFS correlated with T stage (p = 0.002). Local failure was observed in 7 patients (3%). The crude regional failure rate was 9%; isolated regional recurrence was observed in 4%. The distant progression-free survival at 1 and 2 years was 85% and 77%, respectively. SRT was well tolerated and severe late toxicity was observed in less than 3% of patients. Conclusions: SRT is well tolerated in patients with extensive comorbidity with high local control rates and minimal toxicity. Early outcomes are not inferior to those reported for conventional radiotherapy. In view of patient convenience, such risk-adapted SRT schedules should be considered treatment of choice in patients presenting with medically inoperable Stage I NSCLC

  15. Fractionated stereotactic radiotherapy in the treatment of pituitary adenomas

    International Nuclear Information System (INIS)

    Kopp, C.; Theodorou, M.; Poullos, N.; Astner, S.T.; Geinitz, H.; Molls, M.; Stalla, G.K.; Meyer, B.; Nieder, C.; Tromsoe Univ.; Grosu, A.L

    2013-01-01

    Purpose: The purpose of this work was to evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent pituitary adenomas. Patients and methods: We report on 37 consecutive patients with pituitary adenomas treated with FSRT at our department. All patients had previously undergone surgery. Twenty-nine patients had nonfunctioning, 8 had hormone-producing adenoma. The mean total dose delivered by a linear accelerator was 49.4 Gy (range 45-52.2 Gy), 5 x 1.8 Gy weekly. The mean PTV was 22.8 ccm (range 2.0-78.3 ccm). Evaluation included serial imaging tests, endocrinologic and ophthalmologic examination. Results: Tumor control was 91.9 % for a median follow-up time of 57 months (range 2-111 months). Before FSRT partial hypopituitarism was present in 41 % of patients, while 35 % had anterior panhypopituitarism. After FSRT pituitary function remained normal in 22 %, 43 % had partial pituitary dysfunction, and 35 % had anterior panhypopituitarism. Visual acuity was stable in 76 % of patients, improved in 19 %, and deteriorated in 5 %. Visual fields remained stable in 35 patients (95 %), improved in one and worsened in 1 patient (2.7 %). Conclusion: FSRT is an effective and safe treatment for recurrent or residual pituitary adenoma. Good local tumor control and preservation of adjacent structures can be reached, even for large tumors. (orig.)

  16. Fractionated stereotactic radiotherapy in the treatment of pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, C.; Theodorou, M.; Poullos, N.; Astner, S.T.; Geinitz, H.; Molls, M. [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie; Stalla, G.K. [Max-Planck-Institut fuer Psychiatrie, Muenchen (Germany). Klinische Neuroendokrinologie; Meyer, B. [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Neurochirurgische Klinik und Poliklinik; Nieder, C. [Nordland Hospital, Bodoe (Norway). Dept. of Oncology and Palliative Medicine; Tromsoe Univ. (Norway). Inst. of Clinical Medicine; Grosu, A.L [Freiburg Univ. (Germany). Klinik fuer Strahlenheilkunde

    2013-11-15

    Purpose: The purpose of this work was to evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent pituitary adenomas. Patients and methods: We report on 37 consecutive patients with pituitary adenomas treated with FSRT at our department. All patients had previously undergone surgery. Twenty-nine patients had nonfunctioning, 8 had hormone-producing adenoma. The mean total dose delivered by a linear accelerator was 49.4 Gy (range 45-52.2 Gy), 5 x 1.8 Gy weekly. The mean PTV was 22.8 ccm (range 2.0-78.3 ccm). Evaluation included serial imaging tests, endocrinologic and ophthalmologic examination. Results: Tumor control was 91.9 % for a median follow-up time of 57 months (range 2-111 months). Before FSRT partial hypopituitarism was present in 41 % of patients, while 35 % had anterior panhypopituitarism. After FSRT pituitary function remained normal in 22 %, 43 % had partial pituitary dysfunction, and 35 % had anterior panhypopituitarism. Visual acuity was stable in 76 % of patients, improved in 19 %, and deteriorated in 5 %. Visual fields remained stable in 35 patients (95 %), improved in one and worsened in 1 patient (2.7 %). Conclusion: FSRT is an effective and safe treatment for recurrent or residual pituitary adenoma. Good local tumor control and preservation of adjacent structures can be reached, even for large tumors. (orig.)

  17. Radiotherapy fractionation for the palliation of uncomplicated painful bone metastases – an evidence-based practice guideline

    International Nuclear Information System (INIS)

    Wu, Jackson Sai-Yiu; Wong, Rebecca KS; Lloyd, Nancy S; Johnston, Mary; Bezjak, Andrea; Whelan, Timothy

    2004-01-01

    This practice guideline was developed to provide recommendations to clinicians in Ontario on the preferred standard radiotherapy fractionation schedule for the treatment of painful bone metastases. A systematic review and meta-analysis was performed and published elsewhere. The Supportive Care Guidelines Group, a multidisciplinary guideline development panel, formulated clinical recommendations based on their interpretation of the evidence. In addition to evidence from clinical trials, the panel also considered patient convenience and ease of administration of palliative radiotherapy. External review of the draft report by Ontario practitioners was obtained through a mailed survey, and final approval was obtained from the Practice Guidelines Coordinating Committee. Meta-analysis did not detect a significant difference in complete or overall pain relief between single treatment and multifraction palliative radiotherapy for bone metastases. Fifty-nine Ontario practitioners responded to the mailed survey (return rate 62%). Forty-two percent also returned written comments. Eighty-three percent of respondents agreed with the interpretation of the evidence and 75% agreed that the report should be approved as a practice guideline. Minor revisions were made based on feedback from the external reviewers and the Practice Guidelines Coordinating Committee. The Practice Guidelines Coordinating Committee approved the final practice guideline report. For adult patients with single or multiple radiographically confirmed bone metastases of any histology corresponding to painful areas in previously non-irradiated areas without pathologic fractures or spinal cord/cauda equine compression, we conclude that: • Where the treatment objective is pain relief, a single 8 Gy treatment, prescribed to the appropriate target volume, is recommended as the standard dose-fractionation schedule for the treatment of symptomatic and uncomplicated bone metastases. Several factors frequently

  18. Thyroid dysfunction as a late effect in childhood medulloblastoma: a comparison of hyperfractionated versus conventionally fractionated craniospinal radiotherapy

    International Nuclear Information System (INIS)

    Ricardi, Umberto; Corrias, Andrea; Einaudi, Silvia; Genitori, Lorenzo; Sandri, Alessandro; Cordero Di Montezemolo, Luca; Besenzon, Luigi; Madon, Enrico; Urgesi, Alessandro

    2001-01-01

    Purpose: Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of childhood medulloblastoma. Due to the strong radiobiologic rationale, hyperfractionation can reduce the delayed effects of radiation injury. Methods and Materials: The authors compared the incidence of thyroid dysfunction after conventionally fractionated radiotherapy (Group A, n=20 patients) vs. hyperfractionated radiotherapy (Group B, n=12 patients) in a group of pediatric patients with posterior fossa primitive neuroectodermal tumor (PNET). Results: The mean age at the time of tumor diagnosis was 7.4 years in Group A and 8.4 years in Group B. Thyroid function was evaluated yearly, with ultrasonographic examination every 2 years. The patients were followed after diagnosis for a mean of 10.8 years for Group A and 6.0 years for Group B. Approximately 80% of the Group A (16/20) and 33.3% of the Group B (4/12) patients developed primary hypothyroidism within a similar period after irradiation (4.2 vs. 3.5 years, respectively). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (p<0.05). Ultrasonography showed reduced thyroid volume in 7 Group A patients and structural changes in 21 patients (17 Group A, 4 Group B cases); a thyroid benign nodule was detected in 2 Group A patients. Conclusions: The current study findings suggest that the use of hyperfractionated craniospinal radiotherapy in the treatment of childhood medulloblastoma is associated with a lower risk of these patients' developing late thyroid dysfunction

  19. Prediction of the location and size of the stomach using patient characteristics for retrospective radiation dose estimation following radiotherapy

    Science.gov (United States)

    Lamart, Stephanie; Imran, Rebecca; Simon, Steven L.; Doi, Kazutaka; Morton, Lindsay M.; Curtis, Rochelle E.; Lee, Choonik; Drozdovitch, Vladimir; Maass-Moreno, Roberto; Chen, Clara C.; Whatley, Millie; Miller, Donald L.; Pacak, Karel; Lee, Choonsik

    2013-12-01

    Following cancer radiotherapy, reconstruction of doses to organs, other than the target organ, is of interest for retrospective health risk studies. Reliable estimation of doses to organs that may be partially within or fully outside the treatment field requires reliable knowledge of the location and size of the organs, e.g., the stomach, which is at risk from abdominal irradiation. The stomach location and size are known to be highly variable between individuals, but have been little studied. Moreover, for treatments conducted years ago, medical images of patients are usually not available in medical records to locate the stomach. In light of the poor information available to locate the stomach in historical dose reconstructions, the purpose of this work was to investigate the variability of stomach location and size among adult male patients and to develop prediction models for the stomach location and size using predictor variables generally available in medical records of radiotherapy patients treated in the past. To collect data on stomach size and position, we segmented the contours of the stomach and of the skeleton on contemporary computed tomography (CT) images for 30 male patients in supine position. The location and size of the stomach was found to depend on body mass index (BMI), ponderal index (PI), and age. For example, the anteroposterior dimension of the stomach was found to increase with increasing BMI (≈0.25 cm kg-1 m2) whereas its craniocaudal dimension decreased with increasing PI (≈-3.3 cm kg-1 m3) and its transverse dimension increased with increasing PI (≈2.5 cm kg-1 m3). Using the prediction models, we generated three-dimensional computational stomach models from a deformable hybrid phantom for three patients of different BMI. Based on a typical radiotherapy treatment, we simulated radiotherapy treatments on the predicted stomach models and on the CT images of the corresponding patients. Those dose calculations demonstrated good

  20. Cushing's disease: a single centre's experience using the linear accelerator (LINAC) for stereotactic radiosurgery and fractionated stereotactic radiotherapy.

    Science.gov (United States)

    Wilson, P J; Williams, J R; Smee, R I

    2014-01-01

    Cushing's disease is hypercortisolaemia secondary to an adrenocorticotrophic hormone secreting pituitary adenoma. Primary management is almost always surgical, with limited effective medical interventions available. Adjuvant therapy in the form of radiation is gaining popularity, with the bulk of the literature related to the Gamma Knife. We present the results from our own institution using the linear accelerator (LINAC) since 1990. Thirty-six patients who underwent stereotactic radiosurgery (SRS), one patient who underwent fractionated stereotactic radiotherapy (FSRT) and for the purposes of comparison, 13 patients who had undergone conventional radiotherapy prior to 1990, were included in the analysis. Serum cortisol levels improved in nine of 36 (25%) SRS patients and 24 hour urinary free cortisol levels improved in 13 of 36 patients (36.1%). Tumour volume control was excellent in the SRS group with deterioration in only one patient (3%). The patient who underwent FSRT had a highly aggressive tumour refractory to radiation. Published by Elsevier Ltd.

  1. Long term results after fractionated stereotactic radiotherapy (FSRT) in patients with craniopharyngioma: maximal tumor control with minimal side effects

    International Nuclear Information System (INIS)

    Harrabi, Semi B; Adeberg, Sebastian; Welzel, Thomas; Rieken, Stefan; Habermehl, Daniel; Debus, Jürgen; Combs, Stephanie E

    2014-01-01

    There are already numerous reports about high local control rates in patients with craniopharyngioma but there are only few studies with follow up times of more than 10 years. This study is an analysis of long term control, tumor response and side effects after fractionated stereotactic radiotherapy (FSRT) for patients with craniopharyngioma. 55 patients who were treated with FSRT for craniopharyngioma were analyzed. Median age was 37 years (range 6–70 years), among them eight children < 18 years. Radiotherapy (RT) was indicated for progressive disease after neurosurgical resection or postoperatively after repeated resection or partial resection. A median dose of 52.2 Gy (50 – 57.6 Gy) was applied with typical dose per fraction of 1.8 Gy five times per week. The regular follow up examinations comprised in addition to contrast enhanced MRI scans thorough physical examinations and clinical evaluation. During median follow up of 128 months (2 – 276 months) local control rate was 95.3% after 5 years, 92.1% after 10 years and 88.1% after 20 years. Overall survival after 10 years was 83.3% and after 20 years 67.8% whereby none of the deaths were directly attributed to craniopharyngioma. Overall treatment was tolerated well with almost no severe acute or chronic side effects. One patient developed complete anosmia, another one’s initially impaired vision deteriorated further. In 83.6% of the cases with radiological follow up a regression of irradiated tumor residues was monitored, in 7 cases complete response was achieved. 44 patients presented themselves initially with endocrinologic dysfunction none of them showed signs of further deterioration during follow up. No secondary malignancies were observed. Long term results for patients with craniopharyngioma after stereotactic radiotherapy are with respect to low treatment related side effects as well as to local control and overall survival excellent

  2. Phase I/II Trial of Hyperfractionated Concomitant Boost Proton Radiotherapy for Supratentorial Glioblastoma Multiforme

    International Nuclear Information System (INIS)

    Mizumoto, Masashi; Tsuboi, Koji; Igaki, Hiroshi; Yamamoto, Tetsuya; Takano, Shingo; Oshiro, Yoshiko; Hayashi, Yasutaka; Hashii, Haruko; Kanemoto, Ayae; Nakayama, Hidetsugu; Sugahara, Shinji; Sakurai, Hideyuki; Matsumura, Akira; Tokuuye, Koichi

    2010-01-01

    Purpose: To evaluate the safety and efficacy of postoperative hyperfractionated concomitant boost proton radiotherapy with nimustine hydrochloride for supratentorial glioblastoma multiforme (GBM). Methods and Materials: Twenty patients with histologically confirmed supratentorial GBM met the following criteria: (1) a Karnofsky performance status of ≥60; (2) the diameter of the enhanced area before radiotherapy was ≤40 cm; and (3) the enhanced area did not extend to the brain stem, hypothalamus, or thalamus. Magnetic resonance imaging (MRI) T 2 -weighted high area (clinical tumor volume 3 [CTV3]) was treated by x-ray radiotherapy in the morning (50.4 Gy in 28 fractions). More than 6 hours later, 250 MeV proton beams were delivered to the enhanced area plus a 10-mm margin (CTV2) in the first half of the protocol (23.1 GyE in 14 fractions) and to the enhanced volume (CTV1) in the latter half (23.1 GyE in 14 fraction). The total dose to the CTV1 was 96.6 GyE. Nimustine hydrochloride (80 mg/m2) was administered during the first and fourth weeks. Results: Acute toxicity was mainly hematologic and was controllable. Late radiation necrosis and leukoencephalopathy were each seen in one patient. The overall survival rates after 1 and 2 years were 71.1% and 45.3%, respectively. The median survival period was 21.6 months. The 1- and 2-year progression-free survival rates were 45.0% and 15.5%, respectively. The median MRI change-free survival was 11.2 months. Conclusions: Hyperfractionated concomitant boost proton radiotherapy (96.6 GyE in 56 fractions) for GBM was tolerable and beneficial if the target size was well considered. Further studies are warranted to pursue the possibility of controlling border region recurrences.

  3. Comparison of two radiotherapy schemes, conventional and fractionated, in elderly patients suffering from a locally advanced rectum cancer; Comparaison de deux schemas de radiotherapie, classique et hypofractionne, chez les patients ages atteints d'un cancer du rectum localement evolue

    Energy Technology Data Exchange (ETDEWEB)

    Guillerme, F.; Clavier, J.B.; Guihard, S.; Schumacher, C.; Nehme-Schuster, H.; Ben Abdelghani, M.; Noel, G. [Centre Paul-Strauss, Strasbourg (France); Kurtz, J.E.; Brigand, C. [Hopitaux universitaires, Strasbourg (France)

    2011-10-15

    Based on results obtained on 177 patients older than 65 and suffering from T3-4 rectum cancer, and treated either according to a conventional scheme (45 to 50,4 Gy by 1,8 to 2 Gy fractions) or according to a fractionated scheme (39 Gy by 3 Gy fractions), the authors report the comparison of these both methods in terms of toxicity, delay between end of radiotherapy and surgery), histological response, global survival. The hypo-fractionated treatment allows the treatment duration to be reduced, is therefore less constraining and seems more suitable for elderly people. Short communication

  4. Repopulation of FaDu human squamous cell carcinoma during fractionated radiotherapy correlates with reoxygenation

    International Nuclear Information System (INIS)

    Petersen, Cordula; Zips, Daniel; Krause, Mechthild; Schoene, Kerstin; Eicheler, Wolfgang; Hoinkis, Cordelia; Thames, Howard D.; Baumann, Michael

    2001-01-01

    Purpose: FaDu human squamous cell carcinoma (FaDu-hSCC) showed a clear-cut time factor during fractionated radiotherapy (RT) under ambient blood flow. It remained unclear whether this is caused solely by proliferation or if radioresistance resulting from increasing hypoxia contributed to this phenomenon. To address this question, repopulation of clonogenic FaDu cells during fractionated RT under clamp hypoxia was determined by local tumor control assays, and compared to the results after irradiation with the same regimen under ambient blood flow. Methods and Materials: FaDu-hSCC was transplanted into the right hind leg of NMRI nu/nu mice. In the first set of experiments, irradiation was performed under clamp hypoxia. After increasing numbers of 3 Gy fractions (time intervals 24 h or 48 h), graded top-up doses were given to determine the TCD 50 (dose required to control 50% of the tumors). In the second set of experiments, all 3 Gy fractions were applied under ambient conditions, but as in the previous experiments the graded top-up doses were given under clamp hypoxia. A total of 26 TCD 50 assays were performed and analyzed using maximum likelihood techniques. Results: With increasing numbers of daily fractions, the top-up TCD 50 under clamp hypoxia decreased from 39.4 Gy [95% CI 36, 42] after single dose to 19.8 Gy [15, 24] after 18 fractions in 18 days and to 37.8 Gy [31, 44] after 18 fractions in 36 days. The results were consistent with biphasic repopulation, with a switch to rapid repopulation after about 22 days [13, 30]. The clonogen doubling time (T clon ) decreased from 9.8 days [0, 21] in the beginning of RT to 3.4 days after 22 days. Under ambient blood flow the top-up TCD 50 decreased from 37.6 Gy [34, 40] after single dose irradiation to 0 Gy [0, 1] after 18 fractions in 18 days and 22.4 Gy [18, 27] after 18 fractions in 36 days. Similar to results from irradiations under clamp hypoxia, the ambient data were consistent with a biphasic course of clonogen

  5. Randomized Phase III Noninferiority Study Comparing Two Radiotherapy Fractionation Schedules in Patients With Low-Risk Prostate Cancer

    Science.gov (United States)

    Dignam, James J.; Amin, Mahul B.; Bruner, Deborah W.; Low, Daniel; Swanson, Gregory P.; Shah, Amit B.; D’Souza, David P.; Michalski, Jeff M.; Dayes, Ian S.; Seaward, Samantha A.; Hall, William A.; Nguyen, Paul L.; Pisansky, Thomas M.; Faria, Sergio L.; Chen, Yuhchyau; Koontz, Bridget F.; Paulus, Rebecca; Sandler, Howard M.

    2016-01-01

    Purpose Conventional radiotherapy (C-RT) treatment schedules for patients with prostate cancer typically require 40 to 45 treatments that take place from > 8 to 9 weeks. Preclinical and clinical research suggest that hypofractionation—fewer treatments but at a higher dose per treatment—may produce similar outcomes. This trial was designed to assess whether the efficacy of a hypofractionated radiotherapy (H-RT) treatment schedule is no worse than a C-RT schedule in men with low-risk prostate cancer. Patients and Methods A total of 1,115 men with low-risk prostate cancer were randomly assigned 1:1 to C-RT (73.8 Gy in 41 fractions over 8.2 weeks) or to H-RT (70 Gy in 28 fractions over 5.6 weeks). This trial was designed to establish (with 90% power and an α of .05) that treatment with H-RT results in 5-year disease-free survival (DFS) that is not worse than C-RT by more than 7.65% (H-RT/C-RT hazard ratio [HR] < 1.52). Results A total of 1,092 men were protocol eligible and had follow-up information; 542 patients were assigned to C-RT and 550 to H-RT. Median follow-up was 5.8 years. Baseline characteristics were not different according to treatment assignment. The estimated 5-year DFS was 85.3% (95% CI, 81.9 to 88.1) in the C-RT arm and 86.3% (95% CI, 83.1 to 89.0) in the H-RT arm. The DFS HR was 0.85 (95% CI, 0.64 to 1.14), and the predefined noninferiority criterion that required that DFS outcomes be consistent with HR < 1.52 was met (P < .001). Late grade 2 and 3 GI and genitourinary adverse events were increased (HR, 1.31 to 1.59) in patients who were treated with H-RT. Conclusion In men with low-risk prostate cancer, the efficacy of 70 Gy in 28 fractions over 5.6 weeks is not inferior to 73.8 Gy in 41 fractions over 8.2 weeks, although an increase in late GI/genitourinary adverse events was observed in patients treated with H-RT. PMID:27044935

  6. Late Outcomes Following Hypofractionated Conformal Radiotherapy vs. Standard Fractionation for Localized Prostate Cancer: A Nonrandomized Contemporary Comparison

    International Nuclear Information System (INIS)

    Leborgne, Felix; Fowler, Jack

    2009-01-01

    Purpose: To study retrospectively late complications and biochemical control in patients treated with three-dimensional conformal external-beam radiotherapy for localized prostate cancer administered using hypofractionation vs. a standard fractionation regimen. The hypofractionation regimen (Hypo) was designed to avoid more late rectal reactions and to be done in half as many treatment sessions. Methods and Materials: Eighty-nine nonrandomized patients chose Hypo delivered in 20 fractions of 3 Gy (n = 52) or 3.15 Gy (n = 37) for a median overall treatment time of 33 days. One hundred thirty comparable patients were contemporaneously treated with standard fractionation to a median dose of 78 Gy delivered over 55 days. The median follow-up time was 49 months (range, 24-73 months). Results: The 5-year actuarial biochemical control rates were 96%, 84%, and 85% for low-, medium-, and high-risk disease in the Hypo group, respectively. The respective rates in the standard fractionation group were 98%, 84%, and 87%, with no statistical difference between the two groups. The rate of rectal Grade 2-4 complications was 5.5% in both treatment groups and of urinary Grade 2-4 complications was 5.6% in the Hypo and 3% in the standard group (p = 0.36). Similarly, there were no statistical differences in the rate of late complications between patients treated with 3 Gy/fraction vs. 3.15 Gy/fraction. Conclusions: Our preliminary results showed that the Hypo regimen is feasible and does not reduce biochemical control compared with standard fractionation. The incidence of late complications was not increased when the tumor normalized total doses at 2Gy/fraction was increased from 77.1 to 83.7 Gy in patients treated with either 3 or 3.15 Gy/fraction in the Hypo group, respectively.

  7. Predicting Soil-Water Characteristics from Volumetric Contents of Pore-Size Analogue Particle Fractions

    DEFF Research Database (Denmark)

    Naveed, Muhammad; Møldrup, Per; Tuller, Markus

    *-model) for the SWC, derived from readily available soil properties such as texture and bulk density. A total of 46 soils from different horizons at 15 locations across Denmark were used for models evaluation. The Xw-model predicts the volumetric water content as a function of volumetric fines content (organic matter...... and clay). It performed reasonably well for the dry-end (above a pF value of 2.0; pF = log(|Ψ|), where Ψ is the matric potential in cm), but did not do as well closer to saturated conditions. The Xw*-model gives the volumetric water content as a function of volumetric content of particle size fractions...... (organic matter, clay, silt, fine and coarse sand), variably included in the model depending on the pF value. The volumetric content of a particular soil particle size fraction was included in the model if it was assumed to contribute to the pore size fraction still occupied with water at the given p...

  8. Fractionated stereotactic radiotherapy for acoustic neuromas: A prospective monocenter study of about 158 cases

    International Nuclear Information System (INIS)

    Litre, Fabien; Rousseaux, Pascal; Jovenin, Nicolas; Bazin, Arnaud; Peruzzi, Philippe; Wdowczyk, Didier; Colin, Philippe

    2013-01-01

    Purpose: To evaluate long-term outcomes and efficacy of fractionated stereotactic radiotherapy in the treatment of acoustic neuromas. Material and methods: Between January 1996 and December 2009, 158 acoustic neuromas were treated by FSR in 155 patients. They received a dose of 50.4 Gy, with a safety margin of 1–2 mm with a median tumor volume at 2.45 mL (range: 0.17–12.5 mL) and a median follow-up duration at 60 months (range: 24–192). Results: FSR was well tolerated in all patients with mild sequelae consisting in radiation-induced trigeminal nerve impairments (3.2%), Grade 2 facial neuropathies (2.5%), new or aggravated tinnitus (2.1%) and VP shunting (2.5%). The treatment failed in four patients (2.5%) who had subsequent surgery respectively at 20, 38, 45 and 84 months post-FSR. The local tumor control rates were respectively 99.3%, 97.5% and 95.2% at 3, 5 and >7-year of follow-up. For initial Gardner–Robertson Grade 1 and 2 ANs, the preservation of useful hearing was possible in 54% of the cases; only Grade 1 ANs had stabilized during the course of the follow-up with 71% >7 years. However, hearing preservation was not correlated to the initial Koos Stage and to the radiation dose delivered to the cochlea. Tinnitus (70%), vertigo (59%), imbalance (46%) and ear mastoid pain (43%) had greatly improved post-FRS in most patients. Tumor control, hearing preservation and FRS toxicity were quite similar in patients with NF2, cystic acoustic neuroma, prior surgical resection and Koos Stage 4 AN. No secondary tumors were observed. Conclusion: FSR is a safe and effective therapeutic for acoustic neuromas and could be an alternative to microsurgery. Compared to radiosurgery, there are no contraindications for fractioned doses of stereotactic radiotherapy especially for Stage-4 tumors and patients at high risk of hearing loss

  9. Fractionated stereotactic radiotherapy for acoustic neuromas: A prospective monocenter study of about 158 cases

    Energy Technology Data Exchange (ETDEWEB)

    Litre, Fabien [Hôpital Maison Blanche, Reims Cedex (France); Rousseaux, Pascal [Hôpital Maison Blanche, Reims Cedex (France); Jovenin, Nicolas [Institut Jean Godinot, Reims Cedex (France); Bazin, Arnaud; Peruzzi, Philippe [Hôpital Maison Blanche, Reims Cedex (France); Wdowczyk, Didier; Colin, Philippe [Institut du Cancer Reims Courlancy, Reims (France)

    2013-02-15

    Purpose: To evaluate long-term outcomes and efficacy of fractionated stereotactic radiotherapy in the treatment of acoustic neuromas. Material and methods: Between January 1996 and December 2009, 158 acoustic neuromas were treated by FSR in 155 patients. They received a dose of 50.4 Gy, with a safety margin of 1–2 mm with a median tumor volume at 2.45 mL (range: 0.17–12.5 mL) and a median follow-up duration at 60 months (range: 24–192). Results: FSR was well tolerated in all patients with mild sequelae consisting in radiation-induced trigeminal nerve impairments (3.2%), Grade 2 facial neuropathies (2.5%), new or aggravated tinnitus (2.1%) and VP shunting (2.5%). The treatment failed in four patients (2.5%) who had subsequent surgery respectively at 20, 38, 45 and 84 months post-FSR. The local tumor control rates were respectively 99.3%, 97.5% and 95.2% at 3, 5 and >7-year of follow-up. For initial Gardner–Robertson Grade 1 and 2 ANs, the preservation of useful hearing was possible in 54% of the cases; only Grade 1 ANs had stabilized during the course of the follow-up with 71% >7 years. However, hearing preservation was not correlated to the initial Koos Stage and to the radiation dose delivered to the cochlea. Tinnitus (70%), vertigo (59%), imbalance (46%) and ear mastoid pain (43%) had greatly improved post-FRS in most patients. Tumor control, hearing preservation and FRS toxicity were quite similar in patients with NF2, cystic acoustic neuroma, prior surgical resection and Koos Stage 4 AN. No secondary tumors were observed. Conclusion: FSR is a safe and effective therapeutic for acoustic neuromas and could be an alternative to microsurgery. Compared to radiosurgery, there are no contraindications for fractioned doses of stereotactic radiotherapy especially for Stage-4 tumors and patients at high risk of hearing loss.

  10. Dynamics of size-fractionated phytoplankton biomass in a monsoonal estuary: Patterns and drivers for seasonal and spatial variability

    Science.gov (United States)

    Rajaneesh, K. M.; Mitbavkar, Smita; Anil, Arga Chandrashekar

    2018-07-01

    Phytoplankton size-fractionated biomass is an important determinant of the type of food web functioning in aquatic ecosystems. Knowledge about the effect of seasonal salinity gradient on the size-fractionated biomass dynamics is still lacking, especially in tropical estuaries experiencing monsoon. The phytoplankton size-fractionated chlorophyll a biomass (>3 μm and 3 μm size-fraction was the major contributor to the total phytoplankton chlorophyll a biomass with the ephemeral dominance of biomass concentration of both size-fractions showed signs of recovery with increasing salinity downstream towards the end of the monsoon season. In contrast, the chlorophyll a biomass response was size-dependent during the non-monsoon seasons with the sporadic dominance (>50%) of biomass during high water temperature episodes from downstream to middle estuary during pre-monsoon and at low salinity and high nutrient conditions upstream during post-monsoon. These conditions also influenced the picophytoplankton community structure with picoeukaryotes dominating during the pre-monsoon, phycoerythrin containing Synechococcus during the monsoon and phycocyanin containing Synechococcus during the post-monsoon. This study highlights switching over of dominance in size-fractionated phytoplankton chlorophyll a biomass at intra, inter-seasonal and spatial scales which will likely govern the estuarine trophodynamics.

  11. Tumor shrinkage assessed by volumetric MRI in the long-term follow-up after stereotactic radiotherapy of meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    Astner, Sabrina T.; Theodorou, Marilena; Dobrei-Ciuchendea, Mihaela; Kopp, Christine; Molls, Michael [Dept. of Radiotherapy and Radiooncology, Klinikum rechts der Isar, Technical Univ. of Munich (Germany); Auer, Florian [Dept. of Neuroradiology, Klinikum rechts der Isar, Technical Univ. of Munich (Germany); Grosu, Anca-Ligia [Dept. of Radiotherapy, Univ. Hospital Freiburg (Germany)

    2010-08-15

    Purpose: To evaluate tumor volume reduction in the follow-up of meningiomas after fractionated stereotactic radiotherapy (FSRT) or linac radiosurgery (RS) by using magnetic resonance imaging (MRI). Patients and Methods: In 59 patients with skull base meningiomas, gross tumor volume (GTV) was outlined on contrast-en-hanced MRI before and median 50 months (range 11-92 months) after stereotactic radiotherapy. MRI was performed as an axial three-dimensional gradient-echo T1-weighted sequence at 1.6 mm slice thickness without gap (3D-MRI). Results were compared to the reports of diagnostic findings. Results: Mean tumor size of all 59 meningiomas was 13.9 ml (0.8-62.9 ml) before treatment. There was shrinkage of the treated meningiomas in all but one patient. Within a median volumetric follow-up of 50 months (11-95 months), an absolute mean volume reduction of 4 ml (0-18 ml) was seen. The mean relative size reduction compared to the volume before radiotherapy was 27% (0-73%). Shrinkage measured by 3D-MRI was greater at longer time intervals after radiotherapy. The mean size reduction was 17%, 23%, and 30% (at < 24 months, 24-48 months, and 48-72 months). Conclusion: By using 3D-MRI in almost all patients undergoing radiotherapy of a meningioma, tumor shrinkage is detected. The data presented here demonstrate that volumetric assessment from 3D-MRI provides additional information to routinely used radiologic response measurements. After FSRT or RS, a mean size reduction of 25-45% can be expected within 4 years. (orig.)

  12. Late Toxicities after Conventional Radiotherapy for Nasopharyngeal Carcinoma: Incidence and Risk Factors

    International Nuclear Information System (INIS)

    Siala, W.; Mnejja, W.; Elloumi, F.; Daoud, J.; Ghorbel, A.; Mnif, J.; Frikha, M.

    2014-01-01

    Background. To determine the incidence and analyze the factors affecting late toxicity for nasopharyngeal carcinoma patients treated with conventional radiotherapy. Patients and Methods. Retrospective analysis was performed on 239 NPC patients treated between 1993 and 2004 in our institution. One hundred and fifty-seven patients were treated with conventional fractionation (2 Gy per fraction, 5 fractions per week) and eighty-two patients with hyperfractionated radiotherapy (1.6 Gy per fraction twice a day, 5 days per week). One hundred fifty nine patients underwent neoadjuvant cisplatin based chemotherapy. Late toxicity was evaluated according to the RTOG/EORTC score. Results. Xerostomia was the most common related complication (98.7%). Neoadjuvant chemotherapy and hyperfractionated radiotherapy did not increase late toxicities. Multivariate analyses showed that radiation dose was a significant factor for hearing impairment, younger age for trismus, initial node status for neck fibrosis, and initial dental hygiene for dental complications. Female gender was associated with significantly higher incidence of trismus and hearing impairment. Conclusion. Conventional radiotherapy was associated with a high rate of late toxicities which affect patients’ quality of life. With the development of three-dimensional conformal radiotherapy and intensity modulated radiotherapy, a reduced incidence of radiation related complications could be expected.

  13. TH-CD-202-11: Implications for Online Adaptive and Non-Adaptive Radiotherapy of Gastic and Gastroesophageal Junction Cancers Using MRI-Guided Radiotherapy

    International Nuclear Information System (INIS)

    Mittauer, K; Geurts, M; Toya, R; Bassetti, M; Harari, P; Paliwal, B; Bayouth, J

    2016-01-01

    Purpose: Radiotherapy for gastric and gastroesophageal junction (GEJ) tumors commonly requires large margins due to deformation, motion and variable changes of the stomach anatomy, at the risk of increased normal tissue toxicities. This work quantifies the interfraction variation of stomach deformation from daily MRI-guided radiotherapy to allow for a more targeted determination of margin expansion in the treatment of gastric and GEJ tumors. Methods: Five patients treated for gastric (n=3) and gastroesophageal junction (n=2) cancers with conventionally fractionated radiotherapy underwent daily MR imaging on a clinical MR-IGRT system. Treatment planning and contours were performed based on the MR simulation. The stomach was re-contoured on each daily volumetric setup MR. Dice similarity coefficients (DSC) of the daily stomach were computed to evaluate the stomach interfraction deformation. To evaluate the stomach margin, the maximum Hausdorff distance (HD) between the initial and fractional stomach surface was measured for each fraction. The margin expansion, needed to encompass all fractions, was evaluated from the union of all fractional stomachs. Results: In total, 94 fractions with daily stomach contours were evaluated. For the interfraction stomach differences, the average DSC was 0.67±0.1 for gastric and 0.62±0.1 for GEJ cases. The maximum HD of each fraction was 3.5±2.0cm (n=94) with mean HD of 0.8±0.4cm (across all surface voxels for all fractions). The margin expansion required to encompass all individual fractions (averaged across 5 patients) was 1.4 cm(superior), 2.3 cm(inferior), 2.5 cm(right), 3.2 cm(left), 3.7 cm(anterior), 3.4 cm(posterior). Maximum observed difference for margin expansion was 8.7cm(posterior) among one patient. Conclusion: We observed a notable interfractional change in daily stomach shape (i.e., mean DSC of 0.67, p<0.0001) in both gastric and GEJ patients, for which adaptive radiotherapy is indicated. A minimum PTV margin of 3

  14. TH-CD-202-11: Implications for Online Adaptive and Non-Adaptive Radiotherapy of Gastic and Gastroesophageal Junction Cancers Using MRI-Guided Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mittauer, K; Geurts, M; Toya, R; Bassetti, M; Harari, P; Paliwal, B; Bayouth, J [University of Wisconsin, Madison, WI (United States)

    2016-06-15

    Purpose: Radiotherapy for gastric and gastroesophageal junction (GEJ) tumors commonly requires large margins due to deformation, motion and variable changes of the stomach anatomy, at the risk of increased normal tissue toxicities. This work quantifies the interfraction variation of stomach deformation from daily MRI-guided radiotherapy to allow for a more targeted determination of margin expansion in the treatment of gastric and GEJ tumors. Methods: Five patients treated for gastric (n=3) and gastroesophageal junction (n=2) cancers with conventionally fractionated radiotherapy underwent daily MR imaging on a clinical MR-IGRT system. Treatment planning and contours were performed based on the MR simulation. The stomach was re-contoured on each daily volumetric setup MR. Dice similarity coefficients (DSC) of the daily stomach were computed to evaluate the stomach interfraction deformation. To evaluate the stomach margin, the maximum Hausdorff distance (HD) between the initial and fractional stomach surface was measured for each fraction. The margin expansion, needed to encompass all fractions, was evaluated from the union of all fractional stomachs. Results: In total, 94 fractions with daily stomach contours were evaluated. For the interfraction stomach differences, the average DSC was 0.67±0.1 for gastric and 0.62±0.1 for GEJ cases. The maximum HD of each fraction was 3.5±2.0cm (n=94) with mean HD of 0.8±0.4cm (across all surface voxels for all fractions). The margin expansion required to encompass all individual fractions (averaged across 5 patients) was 1.4 cm(superior), 2.3 cm(inferior), 2.5 cm(right), 3.2 cm(left), 3.7 cm(anterior), 3.4 cm(posterior). Maximum observed difference for margin expansion was 8.7cm(posterior) among one patient. Conclusion: We observed a notable interfractional change in daily stomach shape (i.e., mean DSC of 0.67, p<0.0001) in both gastric and GEJ patients, for which adaptive radiotherapy is indicated. A minimum PTV margin of 3

  15. A comparison of anti-tumor effects of high dose rate fractionated and low dose rate continuous irradiation in multicellular spheroids

    International Nuclear Information System (INIS)

    Kubota, Nobuo; Omura, Motoko; Matsubara, Sho.

    1997-01-01

    In a clinical experience, high dose rate (HDR) fractionated interstitial radiotherapy can be an alternative to traditional low dose rate (LDR) continuous interstitial radiotherapy for head and neck cancers. To investigate biological effect of HDR, compared to LDR, comparisons have been made using spheroids of human squamous carcinoma cells. Both LDR and HDR were delivered by 137 Cs at 37degC. Dose rate of LDR was 8 Gy/day and HDR irradiations of fraction size of 4, 5 or 6 Gy were applied twice a day with an interval time of more than 6 hr. We estimated HDR fractionated dose of 31 Gy with 4 Gy/fr to give the same biological effects of 38 Gy by continuous LDR for spheroids. The ratio of HDR/LDR doses to control 50% spheroids was 0.82. (author)

  16. Fractionated stereotactically guided radiotherapy and radiosurgery in the treatment of functional and nonfunctional adenomas of the pituitary gland

    International Nuclear Information System (INIS)

    Milker-Zabel, Stefanie; Debus, Juergen; Thilmann, Christoph; Schlegel, Wolfgang; Wannenmacher, Michael

    2001-01-01

    Purpose: We evaluated survival rates and side effects after fractionated stereotactically guided radiotherapy (SCRT) and radiosurgery in patients with pituitary adenoma. Methods and Materials: Between 1989 and 1998, 68 patients were treated with FSRT (n=63) or radiosurgery (n=5) for pituitary adenomas. Twenty-six had functional and 42 had nonfunctional adenomas. Follow-up included CT/MRI, endocrinologic, and ophthalmologic examinations. Mean follow-up was 38.7 months. Seven patients received radiotherapy as primary treatment and 39 patients received it postoperatively for residual disease. Twenty-two patients were treated for recurrent disease after surgery. Mean total dose was 52.2 Gy for SCRT, and 15 Gy for radiosurgery. Results: Overall local tumor control was 93% (60/65 patients). Forty-three patients had stable disease based on CT/MRI, while 15 had a reduction of tumor volume. After FSRT, 26% with a functional adenoma had a complete remission and 19% had a reduction of hormonal overproduction after 34 months' mean. Two patients with STH-secreting adenomas had an endocrinologic recurrence, one with an ACTH-secreting adenoma radiologic recurrence, within 54 months. Reduction of visual acuity was seen in 4 patients and partial hypopituitarism in 3 patients. None of the patients developed brain radionecrosis or radiation-induced gliomas. Conclusion: Stereotactically guided radiotherapy is effective and safe in the treatment of pituitary adenomas to improve local control and reduce hormonal overproduction

  17. Treatment outcome in patients with vulvar cancer: comparison of concurrent radiotherapy to postoperative radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ja Young; Kim, Sung Hwan; Kim, Ki Won; Park, Dong Choon; Yoon, Joo Hee; Yoon, Sei Chul [St. Vincent' s Hospital, The Catholic University of Korea School of Medicine, Seoul (Korea, Republic of); Yu, Mina [St. Mary' s Hospital, The Catholic University of Korea School of Medicine, Seoul (Korea, Republic of)

    2012-03-15

    To evaluate outcome and morbidity in patients with vulvar cancer treated with radiotherapy, concurrent chemoradiotherapy or postoperative radiotherapy. The records of 24 patients treated with radiotherapy for vulvar cancer between July 1993 and September 2009 were retrospectively reviewed. All patients received once daily 1.8-4 Gy fractions external beam radiotherapy to median 51.2 Gy (range, 19.8 to 81.6 Gy) on pelvis and inguinal nodes. Seven patients were treated with primary concurrent chemoradiotherapy, one patient was treated with primary radiotherapy alone, four patients received palliative radiotherapy, and twelve patients were treated with postoperative radiotherapy. Twenty patients were eligible for response evaluation. Response rate was 55% (11/20). The 5-year disease free survival was 42.2% and 5-year overall survival was 46.2%, respectively. Fifty percent (12/24) experienced with acute skin complications of grade III or more during radiotherapy. Late complications were found in 8 patients. 50% (6/12) of patients treated with lymph node dissection experienced severe late complications. One patient died of sepsis from lymphedema. However, only 16.6% (2/12) of patients treated with primary radiotherapy developed late complications. Outcome of patients with vulvar cancer treated with radiotherapy showed relatively good local control and low recurrence. Severe late toxicities remained higher in patients treated with both node dissection and radiotherapy.

  18. Different rectal toxicity tolerance with and without simultaneous conventionally-fractionated pelvic lymph node treatment in patients receiving hypofractionated prostate radiotherapy

    International Nuclear Information System (INIS)

    McDonald, Andrew M; Baker, Christopher B; Popple, Richard A; Shekar, Kiran; Yang, Eddy S; Jacob, Rojymon; Cardan, Rex; Kim, Robert Y; Fiveash, John B

    2014-01-01

    To investigate added morbidity associated with the addition of pelvic elective nodal irradiation (ENI) to hypofractionated radiotherapy to the prostate. Two-hundred twelve patients, treated with hypofractionated radiotherapy to the prostate between 2004 and 2011, met the inclusion criteria for the analysis. All patients received 70 Gy to the prostate delivered over 28 fractions and 103 (49%) received ENI consisting of 50.4 Gy to the pelvic lymphatics delivered simultaneously in 1.8 Gy fractions. The mean dose-volume histograms were compared between the two subgroups defined by use of ENI, and various dose-volume parameters were analyzed for effect on late lower gastrointestinal (GI) and genitourinary (GU) toxicity. Acute grade 2 lower GI toxicity occurred in 38 (37%) patients receiving ENI versus 19 (17%) in those who did not (p = 0.001). The Kaplan-Meier estimate of grade ≥ 2 lower GI toxicity at 3 years was 15.3% for patients receiving ENI versus 5.3% for those who did not (p = 0.026). Each rectal isodose volume was increased for patients receiving ENI up to 50 Gy (p ≤ 0.021 for each 5 Gy increment). Across all patients, the absolute V 70 of the rectum was the only predictor of late GI toxicity. When subgroups, defined by the use of ENI, were analyzed separately, rectal V 70 was only predictive of late GI toxicity for patients who received ENI. For patients receiving ENI, V 70 > 3 cc was associated with an increased risk of late GI events. Elective nodal irradiation increases the rates of acute and late GI toxicity when delivered simultaneously with hypofractioanted prostate radiotherapy. The use of ENI appears to sensitize the rectum to hot spots, therefore we recommend added caution to minimize the volume of rectum receiving 100% of the prescription dose in these patients

  19. Different rectal toxicity tolerance with and without simultaneous conventionally-fractionated pelvic lymph node treatment in patients receiving hypofractionated prostate radiotherapy.

    Science.gov (United States)

    McDonald, Andrew M; Baker, Christopher B; Popple, Richard A; Shekar, Kiran; Yang, Eddy S; Jacob, Rojymon; Cardan, Rex; Kim, Robert Y; Fiveash, John B

    2014-06-03

    To investigate added morbidity associated with the addition of pelvic elective nodal irradiation (ENI) to hypofractionated radiotherapy to the prostate. Two-hundred twelve patients, treated with hypofractionated radiotherapy to the prostate between 2004 and 2011, met the inclusion criteria for the analysis. All patients received 70 Gy to the prostate delivered over 28 fractions and 103 (49%) received ENI consisting of 50.4 Gy to the pelvic lymphatics delivered simultaneously in 1.8 Gy fractions. The mean dose-volume histograms were compared between the two subgroups defined by use of ENI, and various dose-volume parameters were analyzed for effect on late lower gastrointestinal (GI) and genitourinary (GU) toxicity. Acute grade 2 lower GI toxicity occurred in 38 (37%) patients receiving ENI versus 19 (17%) in those who did not (p = 0.001). The Kaplan-Meier estimate of grade ≥ 2 lower GI toxicity at 3 years was 15.3% for patients receiving ENI versus 5.3% for those who did not (p = 0.026). Each rectal isodose volume was increased for patients receiving ENI up to 50 Gy (p ≤ 0.021 for each 5 Gy increment). Across all patients, the absolute V70 of the rectum was the only predictor of late GI toxicity. When subgroups, defined by the use of ENI, were analyzed separately, rectal V70 was only predictive of late GI toxicity for patients who received ENI. For patients receiving ENI, V70 > 3 cc was associated with an increased risk of late GI events. Elective nodal irradiation increases the rates of acute and late GI toxicity when delivered simultaneously with hypofractioanted prostate radiotherapy. The use of ENI appears to sensitize the rectum to hot spots, therefore we recommend added caution to minimize the volume of rectum receiving 100% of the prescription dose in these patients.

  20. Collection of size fractionated particulate matter sample for neutron activation analysis in Japan

    International Nuclear Information System (INIS)

    Otoshi, Tsunehiko; Nakamatsu, Hiroaki; Oura, Yasuji; Ebihara, Mitsuru

    2004-01-01

    According to the decision of the 2001 Workshop on Utilization of Research Reactor (Neutron Activation Analysis (NAA) Section), size fractionated particulate matter collection for NAA was started from 2002 at two sites in Japan. The two monitoring sites, ''Tokyo'' and ''Sakata'', were classified into ''urban'' and ''rural''. In each site, two size fractions, namely PM 2-10 '' and PM 2 '' particles (aerodynamic particle size between 2 to 10 micrometer and less than 2 micrometer, respectively) were collected every month on polycarbonate membrane filters. Average concentrations of PM 10 (sum of PM 2-10 and PM 2 samples) during the common sampling period of August to November 2002 in each site were 0.031mg/m 3 in Tokyo, and 0.022mg/m 3 in Sakata. (author)

  1. Diel feeding rhythm of copepod size-fractions from Coliumo Bay, Central Chile

    Directory of Open Access Journals (Sweden)

    Danilo Calliari

    2001-12-01

    Full Text Available The feeding behaviour of the size fractionated copepod assemblage was studied over a diel cycle in Coliumo Bay. In this shallow environment the photic layer reached the bottom and salinity, temperature, and food availability were fairly homogeneous throughout the water column. All four size-fractions (250-500 ?m, 500-1000 ?m, 1000-2000 ?m, >2000 ?m showed a period of high feeding activity during the night and low feeding activity during the day. The persistence of nocturnal feeding in the presence of high food concentration over the 24-h cycle is interpreted as a predator avoidance strategy: empty guts by day make copepods less conspicuous to their visual daytime predators.

  2. Human normal tissue reactions in radiotherapy

    International Nuclear Information System (INIS)

    Taniike, Keiko

    1990-01-01

    Acute and late normal tissue reactions in radiotherapy have not been considered to be major problems with conventional fractionation. But they may cause certain problems when newer schedules such as hyperfractionation or accelerated fractionation are used. In opposing parallel radiotherapy, the dose fractionation of skin or subcutaneous connective tissue are different between in one portal and two portals daily. So we examined acute skin erythema and late connective tissue fibrosis in the two groups (one and two portals) of the patients with uterus cancer. Acute skin erythema and late connective tissue fibrosis were slightly stronger in case of one portal daily. In relation to the anatomical site of skin, acute skin erythema was stronger at the buttocks than the lower abdomen, but late fibrosis was reverse to that. So the degree of acute skin erythema did not predict the degree of late connective tissue fibrosis. The number of Time Dose Fractionation Factor could roughly estimate the degree of erythema and fibrosis. Late fibrosis in 36 fractions increased with an increase of abdominal thickness, but acute erythema did not. (author)

  3. Radiocesium distribution in aggregate-size fractions of cropland and forest soils affected by the Fukushima nuclear accident.

    Science.gov (United States)

    Koarashi, Jun; Nishimura, Syusaku; Atarashi-Andoh, Mariko; Matsunaga, Takeshi; Sato, Tsutomu; Nagao, Seiya

    2018-08-01

    The Fukushima Daiichi nuclear power plant accident caused serious radiocesium ( 137 Cs) contamination in soils in a range of terrestrial ecosystems. It is well documented that the interaction of 137 Cs with soil constituents, particularly clay minerals, in surface soil layers exerts strong control on the behavior of this radionuclide in the environment; however, there is little understanding of how soil aggregation-the binding of soil particles together into aggregates-can affect the mobility and bioavailability of 137 Cs in soils. To explore this, soil samples were collected at seven sites under different land-use conditions in Fukushima and were separated into four aggregate-size fractions: clay-sized (fractions were then analyzed for 137 Cs content and extractability and mineral composition. In forest soils, aggregate formation was significant, and 69%-83% of 137 Cs was associated with macroaggregates and sand-sized aggregates. In contrast, there was less aggregation in agricultural field soils, and approximately 80% of 137 Cs was in the clay- and silt-sized fractions. Across all sites, the 137 Cs extractability was higher in the sand-sized aggregate fractions than in the clay-sized fractions. Mineralogical analysis showed that, in most soils, clay minerals (vermiculite and kaolinite) were present even in the larger-sized aggregate fractions. These results demonstrate that larger-sized aggregates are a significant reservoir of potentially mobile and bioavailable 137 Cs in organic-rich (forest and orchard) soils. Our study suggests that soil aggregation reduces the mobility of particle-associated 137 Cs through erosion and resuspension and also enhances the bioavailability of 137 Cs in soils. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Altered fractionation of hemithorax irradiation for pleural mesothelioma and failure patterns after treatment

    Energy Technology Data Exchange (ETDEWEB)

    Holsti, L.R. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Pyrhoenen, S. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Kajanti, M. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Maentylae, M. [Dept. of Radiotherapy and Oncology, Helsinki University Central Hospital (Finland); Mattson, K. [Dept. of Internal Medicine, Div. of Pulmonary Medicine, Helsinki University Central Hospital (Finland); Maasilta, P. [Dept. of Internal Medicine, Div. of Pulmonary Medicine, Helsinki University Central Hospital (Finland); Kivisaari, L. [Dept. of Diagnostic Radiology, Helsinki University Central Hospital (Finland)

    1997-09-01

    Malignant pleural mesothelioma is a rare malignancy with a bleak prognosis. The role of radiotherapy has not yet been clarified. Our aim was to study the effect of altered fractionation on mesothelioma. We have treated 57 patients, 41 males and 16 females, with hemithorax irradiation with six different fractionation schedules. All the patients have been included in a combined modality program consisting of surgery followed by chemotherapy and finally by hemithorax irradiation. The radiotherapy schedules used were: I. Conventional fractionation of 20 Gy in 10 fractions over 12 days. II, Split-course radiotherapy 55 Gy in 25 fractions of 2.2 Gy over 7 weeks (a two weeks rest halfways) followed by a boost dose of 15 Gy over 8 days to the major tumour area. III. Hyperfractionation of 70 Gy over 7 weeks, 1.25 Gy BID with a 6-h interval and a 10-day rest halfways. IV. Combined hyperfractionation and hypofractionation, 35 Gy hyperfractionation in 28 fractions (1.25 Gy BID with a 6-h interval) over three weeks followed by 36 Gy hypofractionation 9 fractions of 4 Gy given every other day over 3 weeks to the major tumour areas only. V. Hypofractionation of 38.5 Gy over 15 days (9x3.5 Gy). VI. Combined conventional radiotherapy and hypofractionation with 20 Gy given conventionally in 10 fractions followed by 10 fractions of 3 Gy over two weeks, overall time 4 weeks. The 2-year survival rate of all patients was 21% and the 5-year survival rate 9%. Two patients are still alive more than 6 and 9 years after radiotherapy. Progression occurred after surgery in four patients, during and after chemotherapy in 22 patients and after completed radiotherapy in 29 patients. The pattern of progression was similar in each treatment group. (orig.).

  5. Value of conventionally fractionated radiotherapy for the local treatment of HIV associated Kaposi's sarcoma

    International Nuclear Information System (INIS)

    Saran, F.; Adamietz, I.A.; Mose, S.; Thilmann, C.; Boettcher, H.D.

    1995-01-01

    From June 1991 to June 1993, 43 patients with 111 HIV-associated Kaposi's sarcoma of the skin or oral cavity were treated. Lesions were irradiated with 5 to 12 MeV electrons or 60Co gamma-rays. The fractionation scheme was 5 times 2 Gy/week for skin and enoral lesions with a total reference dosage of up to 20 Gy. Side effects were assessed during therapy and the therapeutic result 6 weeks after end of treatment. Thirty-eight out of 111 lesions were judged as complete response (CR) (34%), 61/111 as partial response (PR) (55%) and 12/111 were judged as no change (NC) (11%). Overall response (CR + PR) was 89%. Two patients with lesions of oral cavity suffered from RTOG grade-IV mucositis after 10 and 14 Gy. In 71/106 skin lesions (67%), radiation induced RTOG grade-I reactions were observed. Conclusion: In patients with HIV associated Kaposi's sarcoma effective palliation can be achieved by means of radiotherapy with an overall dose of 20 Gy in conventional fractionation. Yet, the fraction of patients with complete responses is with 34 to 47% lower compared with doses above 20 Gy (66 to 100%). With reference to the reported data our results point to a dose-response relationship for Kaposi's sarcoma. Therefore higher total reference doses, e.g. 30 Gy with weekly 5 times 2 Gy or 24 Gy with 5 times 1.6 Gy for mucous lesions, respectively, are suggested as by this mean the complete response rate can be coubled. (orig./MG) [de

  6. Radiotherapy fractionation for the palliation of uncomplicated painful bone metastases – an evidence-based practice guideline

    Directory of Open Access Journals (Sweden)

    Bezjak Andrea

    2004-10-01

    Full Text Available Abstract Background This practice guideline was developed to provide recommendations to clinicians in Ontario on the preferred standard radiotherapy fractionation schedule for the treatment of painful bone metastases. Methods A systematic review and meta-analysis was performed and published elsewhere. The Supportive Care Guidelines Group, a multidisciplinary guideline development panel, formulated clinical recommendations based on their interpretation of the evidence. In addition to evidence from clinical trials, the panel also considered patient convenience and ease of administration of palliative radiotherapy. External review of the draft report by Ontario practitioners was obtained through a mailed survey, and final approval was obtained from the Practice Guidelines Coordinating Committee. Results Meta-analysis did not detect a significant difference in complete or overall pain relief between single treatment and multifraction palliative radiotherapy for bone metastases. Fifty-nine Ontario practitioners responded to the mailed survey (return rate 62%. Forty-two percent also returned written comments. Eighty-three percent of respondents agreed with the interpretation of the evidence and 75% agreed that the report should be approved as a practice guideline. Minor revisions were made based on feedback from the external reviewers and the Practice Guidelines Coordinating Committee. The Practice Guidelines Coordinating Committee approved the final practice guideline report. Conclusion For adult patients with single or multiple radiographically confirmed bone metastases of any histology corresponding to painful areas in previously non-irradiated areas without pathologic fractures or spinal cord/cauda equine compression, we conclude that: • Where the treatment objective is pain relief, a single 8 Gy treatment, prescribed to the appropriate target volume, is recommended as the standard dose-fractionation schedule for the treatment of symptomatic and

  7. Colloidal transport of uranium in soil: Size fractionation and characterization by field-flow fractionation-multi-detection

    International Nuclear Information System (INIS)

    Claveranne-Lamolere, C.; Lespes, G.; Dubascoux, St.; Potin-Gautier, M.; Claveranne-Lamolere, C.; Aupiais, J.; Pointurier, F.

    2009-01-01

    The aim of this study was to characterize colloids associated with uranium by using an on-line fractionation/multi-detection technique based on asymmetrical flow field-flow fractionation (As-Fl-FFF) hyphenated with UV detector, multi angle laser light scattering (MALLS) and inductively coupling plasma-mass spectrometry (ICP-MS). Moreover, thanks to the As-Fl-FFF, the different colloidal fractions were collected and characterized by a total organic carbon analyzer (TOC). Thus it is possible to determine the nature (organic or inorganic colloids), molar mass, size (gyration and hydrodynamic radii) and quantitative uranium distribution over the whole colloidal phase. In the case of the site studied, two populations are highlighted. The first population corresponds to humic-like substances with a molar mass of (1500 ± 300) g mol -1 and a hydrodynamic diameter of (2. 0 ± 0. 2) nm. The second one has been identified as a mix of carbonated nano-particles or clays with organic particles (aggregates and/or coating of the inorganic particles) with a size range hydrodynamic diameter between 30 and 450 nm. Each population is implied in the colloidal transport of uranium: maximum 1% of the uranium content in soil leachate is transported by the colloids in the site studied, according to the depth in the soil. Indeed, humic substances are the main responsible of this transport in sub-surface conditions whereas nano-particles drive the phenomenon in depth conditions. (authors)

  8. Mineralization of organic phosphorus in soil size fractions under different vegetation covers in the north of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Joice Cleide de Oliveira Rita

    2013-10-01

    Full Text Available In unfertilized, highly weathered tropical soils, phosphorus (P availability to plants is dependent on the mineralization of organic P (Po compounds. The objective of this study was to estimate the mineralization of total and labile Po in soil size fractions of > 2.0, 2.0-0.25 and 2.0 and 2.0-0.25 mm fractions, respectively. In contrast, there was an average increase of 90 % of total Po in microaggregates of 2.0 (-50 % and < 0.25 mm (-76 % fractions, but labile Po increased by 35 % in the 2.0-0.25 mm fraction. The Po fraction relative to total extracted P and total labile P within the soil size fractions varied with the vegetation cover and incubation time. Therefore, the distribution of P fractions (Pi and Po in the soil size fraction revealed the distinctive ability of the cover species to recycle soil P. Consequently, the potential of Po mineralization varied with the size fraction and vegetation cover. Because Po accounted for most of the total labile P, the P availability to plants was closely related to the mineralization of this P fraction.

  9. Inter-fraction variations in respiratory motion models

    Energy Technology Data Exchange (ETDEWEB)

    McClelland, J R; Modat, M; Ourselin, S; Hawkes, D J [Centre for Medical Image Computing, University College London (United Kingdom); Hughes, S; Qureshi, A; Ahmad, S; Landau, D B, E-mail: j.mcclelland@cs.ucl.ac.uk [Department of Oncology, Guy' s and St Thomas' s Hospitals NHS Trust, London (United Kingdom)

    2011-01-07

    Respiratory motion can vary dramatically between the planning stage and the different fractions of radiotherapy treatment. Motion predictions used when constructing the radiotherapy plan may be unsuitable for later fractions of treatment. This paper presents a methodology for constructing patient-specific respiratory motion models and uses these models to evaluate and analyse the inter-fraction variations in the respiratory motion. The internal respiratory motion is determined from the deformable registration of Cine CT data and related to a respiratory surrogate signal derived from 3D skin surface data. Three different models for relating the internal motion to the surrogate signal have been investigated in this work. Data were acquired from six lung cancer patients. Two full datasets were acquired for each patient, one before the course of radiotherapy treatment and one at the end (approximately 6 weeks later). Separate models were built for each dataset. All models could accurately predict the respiratory motion in the same dataset, but had large errors when predicting the motion in the other dataset. Analysis of the inter-fraction variations revealed that most variations were spatially varying base-line shifts, but changes to the anatomy and the motion trajectories were also observed.

  10. Determination of concentration levels of arsenic, gold and antimony in particle-size fractions of gold ore using Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Nyarku, M.

    2009-02-01

    Instrumental Neutron Activation Analysis (INAA) has been used to quantify the concentrations of arsenic, gold and antimony in particle-size fractions of a gold ore. The ore, which was taken from the Ahafo project site of Newmont Ghana Gold Ltd, was first fractionated into fourteen (14) particle-size fractions using state-of-the-art analytical sieve machine. The minimum sieve mesh size used was 36 microns and grains >2000 microns were not considered for analysis. Results of the sieving were analysed with easysieve software. The < 36 microns sub fraction was found to be the optimum, hosting bulk of all three elements. For arsenic, the element was found to be highly concentrated in < 36 to +100 microns size fractions and erratically distributed from +150 microns fraction and above. For gold, in exception of the sub fraction <36 which had exceptionally high concentration, the element is distributed in all the size fractions but slightly 'plays out' in the +150 to +400 microns fractions. Antimony occurrence in the sample was relatively high in <36 microns size fraction followed by 600 - 800, 800 - 1000, 400 - 600 and 36 - 40 microns size fractions in that order. Gold content in the sample was far higher than that of arsenic and antimony. Gold concentration in the composite sample was in the range 564 - 8420 ppm. Arsenic levels were higher as compared to antimony. The range of arsenic concentration in the composite sample was 14.33 - 186.92 ppm. Antimony concentration was in the range 1.09 - 9.48 ppm. (au)

  11. Proton beam radiotherapy of choroidal melanoma: The Liverpool-Clatterbridge experience

    International Nuclear Information System (INIS)

    Damato, Bertil; Kacperek, Andrzej; Chopra, Mona; Campbell, Ian R.; Errington, R. Douglas

    2005-01-01

    Purpose To report on outcomes after proton beam radiotherapy of choroidal melanoma using a 62-MeV cyclotron in patients considered unsuitable for other forms of conservative therapy. Methods and Materials A total of 349 patients with choroidal melanoma referred to the Liverpool Ocular Oncology Centre underwent proton beam radiotherapy at Clatterbridge Centre for Oncology (CCO) between January 1993 and December 2003. Four daily fractions of proton beam radiotherapy were delivered, with a total dose of 53.1 proton Gy, and with lateral and distal safety margins of 2.5 mm. Outcomes measured were local tumor recurrence; ocular conservation; vision; and metastatic death according to age, gender, eye, visual acuity, location of anterior and posterior tumor margins, quadrant, longest basal tumor dimension, tumor height, extraocular extension, and retinal invasion. Results The 5-year actuarial rates were 3.5% for local tumor recurrence, 9.4% for enucleation, 79.1% for conservation of vision of counting fingers or better, 61.1% for conservation of vision of 20/200 or better, 44.8% for conservation of vision of 20/40 or better, and 10.0% for death from metastasis. Conclusion Proton beam radiotherapy with a 62 MeV cyclotron achieves high rates of local tumor control and ocular conservation, with visual outcome depending on tumor size and location

  12. Analysis of oral cancer treated by preoperative radiotherapy

    International Nuclear Information System (INIS)

    Hosokawa, Yoichiro; Kaneko, Masayuki; Yasuda, Motoaki

    1997-01-01

    Fifty-eight patients with squamous cell carcinoma of the oral region, treated by preoperative radiotherapy between January 1988 and December 1993, were reviewed to evaluate the relation between prognosis and pathological findings after preoperative radiotherapy. All patients underwent external radiotherapy of up to 40 Gy in 16 fractions (2.5 Gy a day, 4 fractions a week) before surgery, and the average term from the end of preoperative radiotherapy to surgery were 27.3 days. According to pathological findings during surgery, the patients were divided into a radiation effective group and a radiation noneffective group. There was a significant difference in the survival rates of the two groups, but there was no difference in local control rates. After surgery, regional lymph node metastasis and distant metastasis were more common in the radiation noneffective group than in the radiation effective group. It was considered that regional lymph node metastasis after treatment in the noneffective group is the determining factor in the progress. (author)

  13. Investigating concentration distributions of arsenic, gold and antimony in grain-size fractions of gold ore using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Nyarku, M.; Nyarko, B.J.B.; Serfor-Armah, Y.; Osae, S.

    2010-01-01

    Instrumental neutron activation analysis (INAA) has been used to quantify concentrations of arsenic (As), gold (Au) and antimony (Sb) in grain-size fractions of a gold ore. The ore, which was taken from the Ahafo project site of Newmont Ghana Gold Ltd., was fractionated into 14 grain-size fractions using state-of-the-art analytical sieve machine. The minimum sieve mesh size used was 36 μm and grains >2000 μm were not considered for analysis. Result of the sieving was analysed with easysieve (registered) software. The<36 μm subfraction was found to be the optimum, hosting bulk of all three elements. Arsenic was found to be highly concentrated in<36-100 μm size fractions and erratically distributed in from 150 μm fraction and above. For gold, with the exception of the subfraction <36 μm which had exceptionally high concentration, the element was found to be approximately equally distributed in all the size fractions but slightly 'played out' in 150-400 μm size fractions. Antimony occurrence in the sample was relatively high in <36 μm size fraction followed by 600, 800, 400 and 36 μm size fractions in that order. Gold content in the sample was comparatively far greater than arsenic and antimony; this is indicative of level of gold mineralization in the concession where the sample ore was taken. The concentration of gold in the composite sample was in the range 564-8420 ppm as compared to 14.33-186.92 ppm for arsenic and 1.09-9.48 ppm for antimony. Elemental concentrations were correlated with each other and with grain-size fractions and the relationships between these descriptive parameters were established.

  14. Modified optimal fractionation for poor prognosis malignant gliomas: An elusive search

    International Nuclear Information System (INIS)

    Gupta, Tejpal; Dinshaw, Ketayun

    2005-01-01

    The prognosis of malignant gliomas has not changed much over the last few decades despite refinements in neurosurgical techniques, high-precision radiotherapy, and newer chemotherapeutic agents. The median survival of poor prognosis malignant gliomas (older and/or poor performance status patients) still remains in the range of 6-9 months following maximal safe resection and postoperative conventionally fractionated adjuvant radiotherapy with or without chemotherapy. However, six weeks of daily radiotherapy does seem inappropriate in relation to the short expected survival time in this subset and there is an increasing emphasis on reducing the overall treatment time and the number of hospital visits by such patients. This can be achieved either by accelerated radiotherapy or by hypofractionated radiation, both of which are equivalent to conventional fractionation in terms of palliative effect and survival, as in discussed in this review. Despite enough evidence, such alteration of fractionation has not gained widespread acceptance by the oncologic fraternity. This review has been conducted to collate the evidence that could help shift the paradigm from conventional to modified fractionation in poor prognosis malignant glioma patients

  15. Tribological Characteristics of Tungsten Carbide Reinforced Arc Sprayed Coatings using Different Carbide Grain Size Fractions

    Directory of Open Access Journals (Sweden)

    W. Tillmann

    2017-06-01

    Full Text Available Tungsten carbide reinforced coatings play an important role in the field of surface engineering to protect stressed surfaces against wear. For thermally sprayed coatings, it is already shown that the tribological properties get mainly determined by the carbide grain size fraction. Within the scope of this study, the tribological characteristics of iron based WC-W2C reinforced arc sprayed coatings deposited using cored wires consisting of different carbide grain size fractions were examined. Microstructural characteristics of the produced coatings were scrutinized using electron microscopy and x-ray diffraction analyses. Ball-on-disk test as well as Taber Abraser and dry sand rubber wheel test were employed to analyze both the dry sliding and the abrasive wear behavior. It was shown that a reduced carbide grain size fraction as filling leads to an enhanced wear resistance against sliding. In terms of the Taber Abraser test, it is also demonstrated that a fine carbide grain size fraction results in an improved wear resistant against abrasion. As opposed to that, a poorer wear resistance was found within the dry sand rubber wheel tests. The findings show that the operating mechanisms for both abrasion tests affect the stressed surface in a different way, leading either to microcutting or microploughing.

  16. Determination of subcellular compartment sizes for estimating dose variations in radiotherapy

    International Nuclear Information System (INIS)

    Poole, Christopher M.; Ahnesjo, Anders; Enger, Shirin A.

    2015-01-01

    The variation in specific energy absorbed to different cell compartments caused by variations in size and chemical composition is poorly investigated in radiotherapy. The aim of this study was to develop an algorithm to derive cell and cell nuclei size distributions from 2D histology samples, and build 3D cellular geometries to provide Monte Carlo (MC)-based dose calculation engines with a morphologically relevant input geometry. Stained and unstained regions of the histology samples are segmented using a Gaussian mixture model, and individual cell nuclei are identified via thresholding. Delaunay triangulation is applied to determine the distribution of distances between the centroids of nearest neighbour cells. A pouring simulation is used to build a 3D virtual tissue sample, with cell radii randomised according to the cell size distribution determined from the histology samples. A slice with the same thickness as the histology sample is cut through the 3D data and characterised in the same way as the measured histology. The comparison between this virtual slice and the measured histology is used to adjust the initial cell size distribution into the pouring simulation. This iterative approach of a pouring simulation with adjustments guided by comparison is continued until an input cell size distribution is found that yields a distribution in the sliced geometry that agrees with the measured histology samples. The thus obtained morphologically realistic 3D cellular geometry can be used as input to MC-based dose calculation programs for studies of dose response due to variations in morphology and size of tumour/healthy tissue cells/nuclei, and extracellular material. (authors)

  17. Dosimetric Feasibility of Hypofractionated Proton Radiotherapy for Neoadjuvant Pancreatic Cancer Treatment

    International Nuclear Information System (INIS)

    Kozak, Kevin R.; Kachnic, Lisa A.; Adams, Judith C; Crowley, Elizabeth M.; Alexander, Brian M.; Mamon, Harvey J.; Fernandez-Del Castillo, Carlos; Ryan, David P.; DeLaney, Thomas F.; Hong, Theodore S.

    2007-01-01

    Purpose: To evaluate tumor and normal tissue dosimetry of a 5 cobalt gray equivalent (CGE) x 5 fraction proton radiotherapy schedule, before initiating a clinical trial of neoadjuvant, short-course proton radiotherapy for pancreatic adenocarcinoma. Methods and Materials: The first 9 pancreatic cancer patients treated with neoadjuvant intensity-modulated radiotherapy (1.8 Gy x 28) at the Massachusetts General Hospital had treatment plans generated using a 5 CGE x 5 fraction proton regimen. To facilitate dosimetric comparisons, clinical target volumes and normal tissue volumes were held constant. Plans were optimized for target volume coverage and normal tissue sparing. Results: Hypofractionated proton and conventionally fractionated intensity-modulated radiotherapy plans both provided acceptable target volume coverage and dose homogeneity. Improved dose conformality provided by the hypofractionated proton regimen resulted in significant sparing of kidneys, liver, and small bowel, evidenced by significant reductions in the mean doses, expressed as percentage prescribed dose, to these structures. Kidney and liver sparing was most evident in low-dose regions (≤20% prescribed dose for both kidneys and ≤60% prescribed dose for liver). Improvements in small-bowel dosimetry were observed in high- and low-dose regions. Mean stomach and duodenum doses, expressed as percentage prescribed dose, were similar for the two techniques. Conclusions: A proton radiotherapy schedule consisting of 5 fractions of 5 CGE as part of neoadjuvant therapy for adenocarcinoma of the pancreas seems dosimetrically feasible, providing excellent target volume coverage, dose homogeneity, and normal tissue sparing. Hypofractionated proton radiotherapy in this setting merits Phase I clinical trial investigation

  18. Contrasting responses of bacterial and fungal communities to aggregate-size fractions and long-term fertilizations in soils of northeastern China.

    Science.gov (United States)

    Liao, Hao; Zhang, Yuchen; Zuo, Qinyan; Du, Binbin; Chen, Wenli; Wei, Dan; Huang, Qiaoyun

    2018-04-20

    Soils, with non-uniform distribution of nutrients across different aggregate-size fractions, provide spatially heterogeneous microhabitats for microorganisms. However, very limited information is available on microbial distributions and their response to fertilizations across aggregate-size fractions in agricultural soils. Here, we examined the structures of bacterial and fungal communities across different aggregate-size fractions (2000-250 μm, 250-53 μm and fractions (>53 μm), especially 250-53 μm aggregates, which contain more soil C and N, are associated with greater microbial biomass and higher fungi/bacteria ratio. We firstly reported the fungal community composition in different aggregate-size fractions by HTS technology and found more Ascomycota but less Zygomycota in larger fractions with higher C content across all fertilization regimes. Fertilization and aggregate-size fractions significantly affect the compositions of bacterial and fungal communities although their effects are different. The bacterial community is mainly driven by fertilization, especially chemical fertilizers, and is closely related to the shifts of soil P (phosphorus). The fungal community is preferentially impacted by different aggregate-size fractions and is more associated with the changes of soil C and N. The distinct responses of microbial communities suggest different mechanisms controlling the assembly of soil bacterial and fungal communities at aggregate scale. The investigations of both bacterial and fungal communities could provide a better understanding on nutrient cycling across aggregate-size fractions. Copyright © 2018. Published by Elsevier B.V.

  19. Hypofractionated radiotherapy as local hemostatic agent in advanced cancer

    Directory of Open Access Journals (Sweden)

    Malik Tariq Rasool

    2011-01-01

    Full Text Available Purpose : Tumor bleeding continues to remain a challenge in an oncological setting, and radiotherapy has been studied as a local hemostatic agent. We studied the role of local radiotherapy in controlling bleeding at our center. Materials and Methods : We reviewed 25 treated cases (cancer urinary bladder: 12, lung cancer: 5, cervical cancer: 4, uterine cancer: 1, rectal cancer: 2, schwanoma: 1 at our center from March 2008 to December 2010. All patients had either an advanced or recurrent disease. Radiotherapy schedule was either 20 Gray in 5 fractions or 15 Gray in 5 fractions and was delivered with Cobalt 60. Results and Conclusion : Of 25 patients, 22 (88% responded, and there was complete cessation of bleeding. Both 15 Gray and 20 Gray dose schedule had equal efficacy. Treatment was well tolerated without any intermission. Radiotherapy is a safe and effective option in controlling tumor bleeding.

  20. An anti-angiogenic agent (TNP-470) inhibited reoxygenation during fractionated radiotherapy of murine mammary carcinoma

    International Nuclear Information System (INIS)

    Rumi, Murata; Yasumasa, Nishimura; Masahiro, Hiraoka

    1996-01-01

    Purpose: Angio genesis is one of the important factors for tumor growth. Therefore, an angio genesis inhibitor might decelerate tumor repopulation and is expected to improve the tumor control rate in fractionated radiotherapy (RT). On the other hand, it might increase hypoxic fraction of tumors or inhibit tumor reoxygenation during fractionated RT. This study investigated the effects of an angio genesis inhibitor on fractionated RT. Materials and Methods: Animal-tumors were early generation iso transplants of mammary carcinoma in C3H/He mice. Tumor response was studied by tumor growth (TG) time and TCD-50 (50% tumor control dose) assays. Treatments were started when tumors on the right paw grew 4-5 mm in diameter. Radiation was locally given to tumors in air or under hypoxic condition. An angio genesis inhibitor, TNP-470, a synthetic analogue of fumagillin which is a natural product of Aspergillus fumigatus, has been reported to inhibit endothelial cell growth in vitro. TNP-470 was administered s.c. twice a week at a dose of 100mg/kg. In the TG time assay, fractionated RT was delivered daily for 5 days to a total dose of 10Gy (2Gy/fraction x 5). Two or four doses of TNP-470 were administered during and/or after fractionated RT. The time required for a tumor to reach 3-fold of initial tumor volume (TG time) was determined for each group. In the TCD-50 assay, a single or fractionated irradiation was given alone or in combination with TNP-470. Fractionated irradiation was delivered daily, five times per week, over two weeks (10 fractions). One dose of TNP-470 was administered 24 h prior to a single dose of irradiation, whereas four doses of TNP-470 were given during fractionated RT. Tumors were observed for recurrence once a week for 120 days following the end of RT. Results: The TG time for no treatment group, a group treated with fractionated RT alone, or two doses of TNP-470 alone was 5.3 days (95% confidence limits: 4.8-5.9), 15.6 days (15.1-16.1) or 7.8 days (7

  1. Feasibility and efficacy of helical intensity-modulated radiotherapy for stage III non-small cell lung cancer in comparison with conventionally fractionated 3D-CRT.

    Science.gov (United States)

    He, Jian; Huang, Yan; Chen, Yixing; Shi, Shiming; Ye, Luxi; Hu, Yong; Zhang, Jianying; Zeng, Zhaochong

    2016-05-01

    The standard treatment for stage III non-small-cell lung cancer (NSCLC) is still 60 Gy in conventional fractions combined with concurrent chemotherapy; however, the resulting local controls are disappointing. The aim of this study was to compare and assess the feasibility and efficacy of hypofractionated chemoradiotherapy using helical tomotherapy (HT) with conventional fractionation as opposed to using three-dimensional conformal radiotherapy (3D-CRT) for stage III NSCLC. Sixty-nine patients with stage III (AJCC 7th edition) NSCLC who underwent definitive radiation treatment at our institution between July 2011 and November 2013 were reviewed and analyzed retrospectively. A dose of 60 Gy in 20 fractions was delivered in the HT group (n=34), whereas 60 Gy in 30 fractions in the 3D-CRT group (n=35). Primary endpoints were toxicity, overall response rate, overall survival (OS) and progression-free survival (PFS). The median follow-up period was 26.4 months. V20 (P=0.005), V30 (P=0.001), V40 (P=0.004), mean lung dose (P=0.000) and max dose of spinal cord (P=0.005) were significantly lower in the HT group than in the 3D-CRT group. There was no significant difference in the incidences of acute radiation pneumonitis (RP) ≥ grade 2 between the two groups, whereas the incidences of acute radiation esophagitis ≥ grade 2 were significantly lower in the HT group than in the 3D-CRT group (P=0.027). Two-year overall response rate was significantly higher in the HT group than in the 3D-CRT group (P=0.015). One- and 2-year OS rates were significantly higher in the HT group (95.0% and 68.7%, respectively) than in the 3D-CRT group (85.5% and 47.6%, respectively; P=0.0236). One- and 2-year PFS rates were significantly higher in the HT group (57.8% and 26.3%, respectively) than in the 3D-CRT group (32.7% and 11.4%, respectively; P=0.0351). Univariate analysis indicated that performance status (PS), T stage and radiotherapy technique were significant prognostic factors for both OS

  2. Clinical outcome of stereotactic body radiotherapy of 54 Gy in nine fractions for patients with localized lung tumor using a custom-made immobilization system

    International Nuclear Information System (INIS)

    Aoki, Masahiko; Abe, Yoshinao; Kondo, Hidehiro

    2007-01-01

    The aim of this study was to investigate the clinical outcome of stereotactic body radiotherapy (SBRT) of 54 Gy in nine fractions for patients with localized lung tumor using a custom-made immobilization system. The subjects were 19 patients who had localized lung tumor (11 primaries, 8 metastases) between May 2003 and October 2005. Treatment was conducted on 19 lung tumors by fixed multiple noncoplanar conformal beams with a standard linear accelerator. The isocentric dose was 54 Gy in nine fractions. The median overall treatment time was 15 days (range 11-22 days). All patients were immobilized by a thermo-shell and a custom-made headrest during the treatment. The crude local tumor control rate was 95% during the follow-up of 9.4-39.5 (median 17.7) months. In-field recurrence was noted in only one patient at the last follow-up. The Kaplan-Meier overall survival rate at 2 years was 89.5%. Grade 1 radiation pneumonia and grade 1 radiation fibrosis were observed in 12 of the 19 patients. Treatment-related severe early and late complications were not observed in this series. The stereotactic body radiotherapy of 54 Gy in nine fractions achieved acceptable tumor control without any severe complications. The results suggest that SBRT can be one of the alternatives for patients with localized lung tumors. (author)

  3. Hypofractionation Regimens for Stereotactic Radiotherapy for Large Brain Tumors

    International Nuclear Information System (INIS)

    Yuan Jiankui; Wang, Jian Z.; Lo, Simon; Grecula, John C.; Ammirati, Mario; Montebello, Joseph F.; Zhang Hualin; Gupta, Nilendu; Yuh, William T.C.; Mayr, Nina A.

    2008-01-01

    Purpose: To investigate equivalent regimens for hypofractionated stereotactic radiotherapy (HSRT) for brain tumor treatment and to provide dose-escalation guidance to maximize the tumor control within the normal brain tolerance. Methods and Materials: The linear-quadratic model, including the effect of nonuniform dose distributions, was used to evaluate the HSRT regimens. The α/β ratio was estimated using the Gammaknife stereotactic radiosurgery (GKSRS) and whole-brain radiotherapy experience for large brain tumors. The HSRT regimens were derived using two methods: (1) an equivalent tumor control approach, which matches the whole-brain radiotherapy experience for many fractions and merges it with the GKSRS data for few fractions; and (2) a normal-tissue tolerance approach, which takes advantages of the dose conformity and fractionation of HSRT to approach the maximal dose tolerance of the normal brain. Results: A plausible α/β ratio of 12 Gy for brain tumor and a volume parameter n of 0.23 for normal brain were derived from the GKSRS and whole-brain radiotherapy data. The HSRT prescription regimens for the isoeffect of tumor irradiation were calculated. The normal-brain equivalent uniform dose decreased as the number of fractions increased, because of the advantage of fractionation. The regimens for potential dose escalation of HSRT within the limits of normal-brain tolerance were derived. Conclusions: The designed hypofractionated regimens could be used as a preliminary guide for HSRT dose prescription for large brain tumors to mimic the GKSRS experience and for dose escalation trials. Clinical studies are necessary to further tune the model parameters and validate these regimens

  4. Randomized Comparison of Whole Brain Radiotherapy, 20 Gy in Four Daily Fractions Versus 40 Gy in 20 Twice-Daily Fractions, for Brain Metastases

    International Nuclear Information System (INIS)

    Graham, P.H.; Bucci, J.; Browne, L.

    2010-01-01

    Purpose: The present study compared the intracranial control rate and quality of life for two radiation fractionation schemes for cerebral metastases. Methods and Materials: A total of 113 patients with a Eastern Cooperative Oncology Group performance status 2 months), absent, or concurrent presentation of extracranial disease were randomized to 40 Gy in 20 twice-daily fractions (Arm A) or 20 Gy in four daily fractions (Arm B), stratified by resection status. The European Organization for Research and Treatment of Cancer Quality of Life 30-item questionnaire was administered monthly during Year 1, bimonthly during Year 2, and then every 6 months to Year 5. Results: The patient age range was 28-83 years (mean 62). Of the 113 patients, 41 had undergone surgical resection, and 74 patients had extracranial disease (31 concurrent and 43 stable). The median survival time was 6.1 months in Arm A and 6.6 months in Arm B, and the overall 5-year survival rate was 3.5%. Intracranial progression occurred in 44% of Arm A and 64% of Arm B patients (p = .03). Salvage surgery or radiotherapy was used in 4% of Arm A patients and 21% of Arm B patients (p = .004). Death was attributed to central nervous system progression in 32% of patients in Arm A and 52% of patients in Arm B (p = .03). The toxicity was minimal, with a minor increase in short-term cutaneous reactions in Arm A. The patients' quality of life was not impaired by the more intense treatment in Arm A. Conclusion: Intracranial disease control was improved and the quality of life was maintained with 40 Gy in 20 twice-daily fractions. This schema should be considered for better prognosis subgroups of patients with cerebral metastases.

  5. C and N content in density fractions of whole soil and soil size fraction under cacao agroforestry systems and natural forest in Bahia, Brazil.

    Science.gov (United States)

    Rita, Joice Cleide O; Gama-Rodrigues, Emanuela Forestieri; Gama-Rodrigues, Antonio Carlos; Polidoro, Jose Carlos; Machado, Regina Cele R; Baligar, Virupax C

    2011-07-01

    Agroforestry systems (AFSs) have an important role in capturing above and below ground soil carbon and play a dominant role in mitigation of atmospheric CO(2). Attempts has been made here to identify soil organic matter fractions in the cacao-AFSs that have different susceptibility to microbial decomposition and further represent the basis of understanding soil C dynamics. The objective of this study was to characterize the organic matter density fractions and soil size fractions in soils of two types of cacao agroforestry systems and to compare with an adjacent natural forest in Bahia, Brazil. The land-use systems studied were: (1) a 30-year-old stand of natural forest with cacao (cacao cabruca), (2) a 30-year-old stand of cacao with Erythrina glauca as shade trees (cacao + erythrina), and (3) an adjacent natural forest without cacao. Soil samples were collected from 0-10 cm depth layer in reddish-yellow Oxisols. Soil samples was separated by wet sieving into five fraction-size classes (>2000 μm, 1000-2000 μm, 250-1000 μm, 53-250 μm, and 2000 μm) mixed with macroaggregates (32-34%), and microaggregates (1-1.3%). Soil organic carbon (SOC) and total N content increased with increasing soil size fraction in all land-use systems. Organic C-to-total N ratio was higher in the macroaggregate than in the microaggregate. In general, in natural forest and cacao cabruca the contribution of C and N in the light and heavy fractions was similar. However, in cacao + erythrina the heavy fraction was the most common and contributed 67% of C and 63% of N. Finding of this study shows that the majority of C and N in all three systems studied are found in macroaggregates, particularly in the 250-1000 μm size aggregate class. The heavy fraction was the most common organic matter fraction in these soils. Thus, in mature cacao AFS on highly weathered soils the main mechanisms of C stabilization could be the physical protection within macroaggregate structures thereby

  6. C and N Content in Density Fractions of Whole Soil and Soil Size Fraction Under Cacao Agroforestry Systems and Natural Forest in Bahia, Brazil

    Science.gov (United States)

    Rita, Joice Cleide O.; Gama-Rodrigues, Emanuela Forestieri; Gama-Rodrigues, Antonio Carlos; Polidoro, Jose Carlos; Machado, Regina Cele R.; Baligar, Virupax C.

    2011-07-01

    Agroforestry systems (AFSs) have an important role in capturing above and below ground soil carbon and play a dominant role in mitigation of atmospheric CO2. Attempts has been made here to identify soil organic matter fractions in the cacao-AFSs that have different susceptibility to microbial decomposition and further represent the basis of understanding soil C dynamics. The objective of this study was to characterize the organic matter density fractions and soil size fractions in soils of two types of cacao agroforestry systems and to compare with an adjacent natural forest in Bahia, Brazil. The land-use systems studied were: (1) a 30-year-old stand of natural forest with cacao (cacao cabruca), (2) a 30-year-old stand of cacao with Erythrina glauca as shade trees (cacao + erythrina), and (3) an adjacent natural forest without cacao. Soil samples were collected from 0-10 cm depth layer in reddish-yellow Oxisols. Soil samples was separated by wet sieving into five fraction-size classes (>2000 μm, 1000-2000 μm, 250-1000 μm, 53-250 μm, and cacao AFS soils consisted mainly (65 %) of mega-aggregates (>2000 μm) mixed with macroaggregates (32-34%), and microaggregates (1-1.3%). Soil organic carbon (SOC) and total N content increased with increasing soil size fraction in all land-use systems. Organic C-to-total N ratio was higher in the macroaggregate than in the microaggregate. In general, in natural forest and cacao cabruca the contribution of C and N in the light and heavy fractions was similar. However, in cacao + erythrina the heavy fraction was the most common and contributed 67% of C and 63% of N. Finding of this study shows that the majority of C and N in all three systems studied are found in macroaggregates, particularly in the 250-1000 μm size aggregate class. The heavy fraction was the most common organic matter fraction in these soils. Thus, in mature cacao AFS on highly weathered soils the main mechanisms of C stabilization could be the physical

  7. Kinetic considerations in the choice of treatment schedules for neuraxis radiotherapy

    International Nuclear Information System (INIS)

    Wheldon, T.E.

    1993-01-01

    Neuraxis radiotherapy of radiosensitive tumours such as medulloblastoma is usually carried out using conventionally sized fractions and a shrinking field technique. Plowman and Doughty (Br.J.Radiol., 64 (1991) 603-607) have proposed a partial transmission block (PTB) technique which entails the use of small daily doses over a conventional time period. Radiobiological analysis suggests that, although the PTB technique may be adequate for slowly growing tumours, therapeutic efficacy is likely to be compromised where the tumour doubling time is short. Accelerated hyperfractionation (twice daily fractions) provides a possible alternative to both conventional scheduling and the PTB technique. Direct measurement of the kinetics of tumour cells in CSF, where possible, may provide useful guidance in the choice of regimes. (author)

  8. Customized mold radiotherapy with prosthetic apparatus for oral cancers

    International Nuclear Information System (INIS)

    Noguchi, Tadahide; Tsuchiya, Yoshiyuki; Hayasaka, Junichi; Itoh, Hiroto; Jinbu, Yoshinori; Kusama, Mikio; Takahashi, Satoru; Nakazawa, Masanori

    2014-01-01

    Eight patients (6 males, 2 females; median age, 78 years; age range, 31-94 years) were treated by mold radiotherapy with a prosthetic apparatus for oral cancers between October 2006 and March 2013. The primary sites were the tongue in 3 cases, hard palate and buccal mucosa in 2 cases each, and oral floor in 1 case. The type of treatment consisted of radical radiotherapy and palliative radiotherapy in 2 cases each, and preoperative radiotherapy, postoperative radiotherapy, additional radiotherapy after external beam radiotherapy and systemic chemotherapy in 1 case each. Patients received 40-50 Gy in 8-10 fractions with mold radiotherapy. Two patients who received radical radiotherapy showed no signs of recurrence or metastasis. The present therapy contributed to patients' palliative, postoperative, and preoperative therapy. Mold radiotherapy with a prosthetic appliance was performed safely and was a useful treatment for several types of oral cancer. (author)

  9. Photoneutron intensity variation with field size around radiotherapy linear accelerator 18-MeV X-ray beam

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghamdi, H.; Fazal-ur-Rehman [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Jarallah, M.I. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: mibrahim@kfupm.edu.sa; Maalej, N. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2008-08-15

    In X-ray radiotherapy accelerators, neutrons are produced mainly by ({gamma},n) reaction when high energy X-rays interact with high Z materials of the linear accelerator head. These materials include the lead (Pb) used as shielding in the collimator, tungsten (W) target used for the production of X-rays and iron (Fe) in the accelerator head. These unwanted neutrons contaminate the therapeutic beam and contribute to the patient dose during the treatment of a cancer patient. Knowing the neutron distribution around the radiotherapy accelerator is therefore desired. CR-39 nuclear track detectors (NTDs) were used to study the variation of fast and thermal neutron relative intensities around an 18 MeV linear accelerator X-ray beam with the field sizes of 0, 10x10, 20x20, 30x30 and 40x40cm{sup 2}. For fast neutron detection, bare NTDs were used. For thermal neutron detection, NTDs were covered with lithium tetra borate (Li{sub 2}B{sub 4}O{sub 7}) converters. The NTDs were placed at different locations in the direction perpendicular to the treatment couch (transversal) and in the direction parallel to the treatment couch (longitudinal) with respect to the isocenter of the accelerator. The fast neutron relative intensity is symmetrical about the beam axis and exhibits an exponential-like drop with distance from the isocenter of the accelerator for all the field sizes. At the primary beam (isocenter), the relative fast neutron intensity is highest for 40x40cm{sup 2} field size and decreases linearly with the decrease in the field size. However, fast neutron intensities do not change significantly with beam size for the measurements outside the primary beam. The fast neutron intensity in the longitudinal direction outside the primary beam decreases linearly with the field size. The thermal neutron intensity, at any location, was found to be almost independent of the field size.

  10. Fluorescence of soil humic acids and their fractions obtained by tandem size exclusion chromatography-polyacrylamide gel electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Trubetskaya, O. [Russian Academy of Sciences, Moscow Region (Russian Federation). Shemyakin and Ovchinnikov Inst. of Bioorganic Chemistry; Trubetskoj, O. [Russian Academy of Sciences, Moscow Region (Russian Federation). Inst. of Basic Biological Problems; Guyot, G.; Richard, C. [UMR CNRS 6505, Aubiere (France). Lab. de Photochimie Moleculaire et Macromoleculaire; Andreux, F. [Centre des Sciences de la Terre, Dijon (France)

    2002-07-01

    Humic acids (HAs) extracted from soils of different origin (chernozem, ferralsol and ranker) and their fractions (A, B and C+D) obtained by tandem size exclusion chromatography-polyacrylamide gel electrophoresis were investigated by steady-state fluorescence spectroscopy in the emission mode. Independently of HA source, high molecular size fractions A and B are shown to be weakly fluorescent. The main fluorophores, especially those emitting at long wavelength (around 500-510 nm), are contained in the polar and low molecular size fractions C+D. As indicated by the observed pH effect, aromatic structures bearing carboxylate and OH substituents may be involved in these longer wavelength emissions. [author].

  11. Long term results after fractionated stereotactic radiotherapy (FSRT) in patients with craniopharyngioma: maximal tumor control with minimal side effects.

    Science.gov (United States)

    Harrabi, Semi B; Adeberg, Sebastian; Welzel, Thomas; Rieken, Stefan; Habermehl, Daniel; Debus, Jürgen; Combs, Stephanie E

    2014-09-16

    There are already numerous reports about high local control rates in patients with craniopharyngioma but there are only few studies with follow up times of more than 10 years. This study is an analysis of long term control, tumor response and side effects after fractionated stereotactic radiotherapy (FSRT) for patients with craniopharyngioma. 55 patients who were treated with FSRT for craniopharyngioma were analyzed. Median age was 37 years (range 6-70 years), among them eight children craniopharyngioma. Overall treatment was tolerated well with almost no severe acute or chronic side effects. One patient developed complete anosmia, another one's initially impaired vision deteriorated further. In 83.6% of the cases with radiological follow up a regression of irradiated tumor residues was monitored, in 7 cases complete response was achieved. 44 patients presented themselves initially with endocrinologic dysfunction none of them showed signs of further deterioration during follow up. No secondary malignancies were observed. Long term results for patients with craniopharyngioma after stereotactic radiotherapy are with respect to low treatment related side effects as well as to local control and overall survival excellent.

  12. External Beam Radiotherapy in Metastatic Bone Pain from Solid ...

    African Journals Online (AJOL)

    Key Words: Bone, metastasis, radiotherapy, pain, control randomized ... described the efficacy of external beam radiotherapy in pain .... life of patients with multiple myeloma. Eur. J. ... Rades D, Jeremic B, Hoskin PJ: The Role of ... randomised multicenter trial on single fraction ... "The subjective experience of acute pain. An.

  13. EORTC 22972-26991/MRC BR10 trial: Fractionated stereotactic boost following conventional radiotherapy of high grade gliomas

    International Nuclear Information System (INIS)

    Baumert, Brigitta G.; Brada, Michael; Bernier, Jacques; Kortmann, Rolf D.; Dehing-Oberije, Cary; Collette, Laurence; Davis, J. Bernard

    2008-01-01

    Background and purpose: The EORTC trial No. 22972 investigated the role of an additional fractionated stereotactic boost (fSRT) to conventional radiotherapy for patients with high grade gliomas. A quality-assurance (QA) programme was run in conjunction with the study and was the first within the EORTC addressing the quality of a supposedly highly accurate treatment technique such as stereotactic radiotherapy. A second aim was to investigate a possible relation between the clinical results of the stereotactic boost arm and the results of the QA. Materials and methods: The trial was closed in 2001 due to low accrual. In total, 25 patients were randomized: 14 into the experimental arm and 11 into the control arm. Six centres randomized patients, 8 centres had completed the dummy run (DR) for the stereotactic boost part. All participating centres (9) were asked to complete a quality-assurance questionnaire. The DR consisted of treatment planning according to the guidelines of the protocol on 3 different tumour volumes drawn on CT images of a humanized phantom. The SRT technique to be used was evaluated by the questionnaire. Clinical data from patients recruited to the boost arm from 6 participating centres were analysed. Results: There was a full compliance to the protocol requirements for 5 centres. Major and minor deviations in conformality were observed for 2 and 3 centres, respectively. Of the 8 centres which completed the DR, one centre did not comply with the requirements of stereotactic radiotherapy concerning accuracy, dosimetry and planning. Median follow-up and median overall survival were 39.2 and 21.4 months, respectively. Acute and late toxicities of the stereotactic boost were low. One radiation necrosis was seen for a patient who has not received the SRT boost. Three reported serious adverse events were all seizures and probably therapy-related. Conclusions: Overall compliance was good but not ideal from the point of view of this highly precise radiation

  14. Relationship between processing score and kernel-fraction particle size in whole-plant corn silage.

    Science.gov (United States)

    Dias Junior, G S; Ferraretto, L F; Salvati, G G S; de Resende, L C; Hoffman, P C; Pereira, M N; Shaver, R D

    2016-04-01

    Kernel processing increases starch digestibility in whole-plant corn silage (WPCS). Corn silage processing score (CSPS), the percentage of starch passing through a 4.75-mm sieve, is widely used to assess degree of kernel breakage in WPCS. However, the geometric mean particle size (GMPS) of the kernel-fraction that passes through the 4.75-mm sieve has not been well described. Therefore, the objectives of this study were (1) to evaluate particle size distribution and digestibility of kernels cut in varied particle sizes; (2) to propose a method to measure GMPS in WPCS kernels; and (3) to evaluate the relationship between CSPS and GMPS of the kernel fraction in WPCS. Composite samples of unfermented, dried kernels from 110 corn hybrids commonly used for silage production were kept whole (WH) or manually cut in 2, 4, 8, 16, 32 or 64 pieces (2P, 4P, 8P, 16P, 32P, and 64P, respectively). Dry sieving to determine GMPS, surface area, and particle size distribution using 9 sieves with nominal square apertures of 9.50, 6.70, 4.75, 3.35, 2.36, 1.70, 1.18, and 0.59 mm and pan, as well as ruminal in situ dry matter (DM) digestibilities were performed for each kernel particle number treatment. Incubation times were 0, 3, 6, 12, and 24 h. The ruminal in situ DM disappearance of unfermented kernels increased with the reduction in particle size of corn kernels. Kernels kept whole had the lowest ruminal DM disappearance for all time points with maximum DM disappearance of 6.9% at 24 h and the greatest disappearance was observed for 64P, followed by 32P and 16P. Samples of WPCS (n=80) from 3 studies representing varied theoretical length of cut settings and processor types and settings were also evaluated. Each WPCS sample was divided in 2 and then dried at 60 °C for 48 h. The CSPS was determined in duplicate on 1 of the split samples, whereas on the other split sample the kernel and stover fractions were separated using a hydrodynamic separation procedure. After separation, the

  15. Compact and tunable size-based dielectrophoretic flow fractionation

    International Nuclear Information System (INIS)

    Chuang, Han-Sheng; Chung, Tien-Yu; Li, Yun

    2014-01-01

    A compact and tunable size-based flow fractionation microchip using negative dielectrophoresis (DEP) is presented in this paper. In the microchip, a sample containing a mixture of particles is hydrodynamically focused in a contraction section and then sorted by size after flowing over planar interdigitated electrodes. The electrodes and flow chamber were aligned at an angle of 45° to produce effective sorting. 1, 2.5 and 4.8 µm polystyrene (PS) particles were successfully separated into three distinct streams in a short distance (1 mm) and collected in different outlet channels. The sorting was subjected to flow rates and electric potential. The experimental sorting efficiencies of 1, 2.5 and 4.8 µm particles reached 97.2%, 79.6% and 99.8%, respectively. With the same device, lipid vesicle sorting was demonstrated. 86.9% of vesicles larger than 10 µm were effectively extracted from the sample stream. Likewise, sorting of other biological particles can be achieved in the same fashion. (paper)

  16. Development of re-locatable head frame system using hydraulic arms for fractionated stereotactic radiotherapy and CT evaluation of repositioning accuracy

    International Nuclear Information System (INIS)

    Kitamura, Masayuki; Kunieda, Etsuo; Kawaguchi, Osamu; Ando, Yutaka; Shigematsu, Naoyuki; Shiba, Toshiyuki; Kubo, Atsushi

    2002-01-01

    The purpose of this study was to develop a novel re-locatable head frame system consisting of a dental cast and hydraulic arms as an immobilization device for fractionated stereotactic radiotherapy and to evaluate the repositioning accuracy by measurement of landmark coordinates in repeated computed tomography (CT) examinations. The acrylic dental casts were customized for each patient. First the dental cast was attached to the upper jaw of the patient, then the dental cast was connected to a Leksell stereotactic frame, which was finally secured by two hydraulic arms. Since this system is compatible with the Leksell frame, stereotactic indicators could be used to obtain coordinates of anatomical landmarks of the head. Seven patients treated by fractionated stereotactic radiotherapy underwent repeated quality-assurance CTs during their treatment courses. We evaluated the coordinates of the short process of incus and the top of crista galli as reference points for evaluation of variation in a total of 26 repeat CT data sets, and then x, y, and z fluctuations relative to their positions in the treatment-planning CTs. The distances among the reference points of both processes of incus and the top of crista galli were calculated to evaluate the feasibility of the method. The distances were less than 0.5 mm on averages and less than 1 mm in the standard deviations. The respective fluctuations in the x, y and z directions were less than 1 mm in mean values and less than 2 mm in standard deviations. The fluctuations in distance were less than 2 mm on average and in standard deviations. The fluctuation of the center of three reference points was 0.7 mm on average and the rotation of the cranium was 1.0 degree in average. We concluded that our evaluation method is feasible and the reproducibility of the fixation system is acceptable for its routine use in stereotactic radiotherapy. (author)

  17. Preliminary result in patients with primary hepatoma treated by stereotactic radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Ki Mun; Choi, Ihl Bohng; Kim, In Ah; Choi, Byung Ock; Kang, Young Nam; Han, Sung Tae; Chung, Gyu Won [College of Medicine, Catholic Univ., Seoul (Korea, Republic of); Chai, Gyu Young [College of Medicine, Gyeongsang National Univ., Chinju (Korea, Republic of)

    2001-03-01

    It is not common to evaluate the response of the fractionated stereotactic radiotherapy (SRT) to primary hepatoma as compared with conventional radiotherapy. The purpose of the study was to take the preliminary result on the clinical trial of primary hepatoma by SRT. From July 1999 to March 2000, thirty three patients were hospitalized in the St. Mary's Hospital, and treated with SRT for extracranial tumors. Among them, 13 patients were diagnosed to primary hepatoma and then applied by frameless SRT using 6 MV linac accelerator. There were 12 male and 1 female patients. They had the age of 44-66 year old (median: 59) and the tumor size of 10-825 cc (median: 185 cc). SRT was given to them 3-5 fractions a week (5 Gy/fraction, 90% isodose line) for 2-3 weeks. Median dose of SRT was 50 Gy and the range was 30-50 Gy. Follow-up period ranged from 3 months to 13 months with median of 8 months. After treating SRT to thirteen patients with primary hepatoma, the response of the tumor was examined by abdominal CT: they are classified by 1 complete regression (7.7%), 7 partial regression (53.8%), 4 minimal regression (30.8%), 1 stable disease (7.7%). The positive responses more than partial remission were 8 patients (61.5%) after the treatment. The level of serum alpha-fetoprotein (AFP) after the treatment as compared with pretreatment had been 92.3% decreased. There was no severe complication except dyspepsia 84.6%, mild nausea 69.2%, transient decreased of hepatic function 15.4% and fever 7.7%. SRT to the patients with primary hepatoma was potentially suggested to become the safe and more effective tool than the conventional radiotherapy even though there were relatively short duration of follow-up and small numbers to be tested.

  18. Tunable solvation effects on the size-selective fractionation of metal nanoparticles in CO2 gas-expanded solvents.

    Science.gov (United States)

    Anand, Madhu; McLeod, M Chandler; Bell, Philip W; Roberts, Christopher B

    2005-12-08

    This paper presents an environmentally friendly, inexpensive, rapid, and efficient process for size-selective fractionation of polydisperse metal nanoparticle dispersions into multiple narrow size populations. The dispersibility of ligand-stabilized silver and gold nanoparticles is controlled by altering the ligand tails-solvent interaction (solvation) by the addition of carbon dioxide (CO2) gas as an antisolvent, thereby tailoring the bulk solvent strength. This is accomplished by adjusting the CO2 pressure over the liquid, resulting in a simple means to tune the nanoparticle precipitation by size. This study also details the influence of various factors on the size-separation process, such as the types of metal, ligand, and solvent, as well as the use of recursive fractionation and the time allowed for settling during each fractionation step. The pressure range required for the precipitation process is the same for both the silver and gold particles capped with dodecanethiol ligands. A change in ligand or solvent length has an effect on the interaction between the solvent and the ligand tails and therefore the pressure range required for precipitation. Stronger interactions between solvent and ligand tails require greater CO2 pressure to precipitate the particles. Temperature is another variable that impacts the dispersibility of the nanoparticles through changes in the density and the mole fraction of CO2 in the gas-expanded liquids. Recursive fractionation for a given system within a particular pressure range (solvent strength) further reduces the polydispersity of the fraction obtained within that pressure range. Specifically, this work utilizes the highly tunable solvent properties of organic/CO2 solvent mixtures to selectively size-separate dispersions of polydisperse nanoparticles (2 to 12 nm) into more monodisperse fractions (+/-2 nm). In addition to providing efficient separation of the particles, this process also allows all of the solvent and

  19. Impact of radiotherapy on myasthenia gravis in patients with malignant thymomas

    International Nuclear Information System (INIS)

    Hou Xiuyu; Xu Yonggang; Gao Hong; Li Ming; Li Gaofeng; Liu Mingyuan

    2006-01-01

    Objective: To evaluate the change of myasthenia gravis(MG) during radiotherapy for patients with malignant thymomas. Methods: Forty-five with malignant thymomas patients with were analyzed. The median total dose was DT54.2 Gy in 1.8-2.0 Gy/fraction, 5 clays a week. Anti-cholinesterase, such as pyridostigmine was used to control the MG symptoms. Results: Forty-five patients completed radiotherapy on schedule except one from whom the treatment was was with drawn because of respiratory muscle involvement. Among these 44 patients, myasthenic symptom was relieved in 4 to various degrees, 4 progressed, 34 no change and 2 developed cholinergic crisis. Myasthenic symptom was not changed in one patient for whom radiotherapy had been standed before operation nor during the course of postoperative radiotherapy. Conclusions: A course of radiotherapy of DT54.2 Gy, on fractionation of DT1.8-2.0 Gy modal would not aggravate myasthenia. However, proper use of anti-cholinesterase, careful observation and timely drug-adjustment are necessary. (authors)

  20. Radiotherapy of breast fibrosis

    International Nuclear Information System (INIS)

    Heibel, J.H.

    1979-01-01

    In a retrospective study radiotherapy of breast fibrosis in hormone-treated men with histologically confirmed prostate carcinoma was examined. 10 patients had received hormones even before irradiation, 113 obtained hormone administration only after irradiation. The objective size of the glandular body and the overall size of the breast were measured with a special method developed by the author. 46 patients indicated complaints. With hypertrophic mamma and hypertrophic mamilla in 67 examined patients, 127 different symptoms resulted in total. Four patients of the group who had obtained hormones before irradiation, suffered from subjective symptoms. It resulted that radiotherapy of breast fibrosis carried out during hormone treatment is no gynecomastia prophylaxis, that already existent mamma hypertrophies are irreversible, but that existent sensations were notably reduced within 6 months after irradiation therapy. These results indicate the necessity of a radiotherapy of the mamma fibrosis before the hormone treatment is begun. Particularly in cases of higher operative risks, also the possibility of preferring radiotherapy to mastectomy should be fully utilized, in view of adequate or even better therapeutic results. (orig./MG) [de

  1. Results of radiotherapy for epithelial skin cancer of the pinna: the Princess Margaret Hospital experience, 1982-1993

    International Nuclear Information System (INIS)

    Silva, Joaquin J.; Tsang, Richard W.; Panzarella, Tony; Levin, Wilfred; Wells, Woodrow

    2000-01-01

    Purpose: To assess the treatment outcome, late toxicity, and prognostic factors for radiotherapy (RT) of carcinoma of the pinna. Methods and Materials: The charts of 313 patients treated between 01/82 and 12/93 were retrospectively reviewed. There were 334 lesions treated: 201 basal cell carcinoma (BCC), 122 squamous cell carcinoma (SCC), and 11 basosquamous carcinoma. RT was most commonly given by orthovoltage X-rays (278 lesions) or electrons (39 lesions). The most frequently used dose prescriptions were 35 Gy in 5 fractions (123 treatments with median field size = 4.9 cm 2 ), 42.5-45 Gy in 10 fractions (67 treatments with median field size = 10.5 cm 2 ), and 50-65 Gy in 20-30 fractions (42 treatments with median field size = 81 cm 2 ). Results: The actuarial 2- and 5-year local control rates were 86.6% and 79.2%. Multivariate analysis revealed two factors to be statistically significant for increased local failure: tumor size > 2 cm (hazard ratio [HR] = 2.66, 95% confidence interval [CI] = 1.16-6.08), and a low biological effective dose (BED) (for each decrease of 5 BED units, HR = 1.76, 95% CI 1.07-2.88). The 5-year actuarial rate of significant Grade 4 late toxicity was 7.3%. Factors statistically significant for this endpoint on univariate analysis were tumor size (p = 0.035), T-stage (p = 0.02), field size (p 0.05), fraction size (p = 0.003), and BED (p = 0.05). Conclusions: RT is an effective treatment option for epithelial skin cancer of the pinna. Large tumor size and low BED were independently statistically significantly associated with increased local failure. Dose-fractionation schedules using fraction sizes 5 cm 2

  2. Treatment accuracy of fractionated stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Kumar, Shaleen; Burke, Kevin; Nalder, Colin; Jarrett, Paula; Mubata, Cephas; A'Hern, Roger; Humphreys, Mandy; Bidmead, Margaret; Brada, Michael

    2005-01-01

    Background and purpose: To assess the geometric accuracy of the delivery of fractionated stereotactic radiotherapy (FSRT) for brain tumours using the Gill-Thomas-Cosman (GTC) relocatable frame. Accuracy of treatment delivery was measured via portal images acquired with an amorphous silicon based electronic portal imager (EPI). Results were used to assess the existing verification process and to review the current margins used for the expansion of clinical target volume (CTV) to planning target volume (PTV). Patients and methods: Patients were immobilized in a GTC frame. Target volume definition was performed on localization CT and MRI scans and a CTV to PTV margin of 5 mm (based on initial experience) was introduced in 3D. A Brown-Roberts-Wells (BRW) fiducial system was used for stereotactic coordinate definition. The existing verification process consisted of an intercomparison of the coordinates of the isocentres and anatomy between the localization and verification CT scans. Treatment was delivered with 6 MV photons using four fixed non-coplanar conformal fields using a multi-leaf collimator. Portal imaging verification consisted of the acquisition of orthogonal images centred through the treatment isocentre. Digitally reconstructed radiographs (DRRs) created from the CT localization scans were used as reference images. Semi-automated matching software was used to quantify set up deviations (displacements and rotations) between reference and portal images. Results: One hundred and twenty six anterior and 123 lateral portal images were available for analysis for set up deviations. For displacements, the total errors in the cranial/caudal direction were shown to have the largest SD's of 1.2 mm, while systematic and random errors reached SD's of 1.0 and 0.7 mm, respectively, in the cranial/caudal direction. The corresponding data for rotational errors (the largest deviation was found in the sagittal plane) was 0.7 deg. SD (total error), 0.5 deg. (systematic) and 0

  3. Stereotactic body radiotherapy for lung cancer: how much does it really cost?

    Science.gov (United States)

    Lievens, Yolande; Obyn, Caroline; Mertens, Anne-Sophie; Van Halewyck, Dries; Hulstaert, Frank

    2015-03-01

    Despite the lack of randomized evidence, stereotactic body radiotherapy (SBRT) is being accepted as superior to conventional radiotherapy for patients with T1-2N0 non-small-cell lung cancer in the periphery of the lung and unfit or unwilling to undergo surgery. To introduce SBRT in a system of coverage with evidence development, a correct financing had to be determined. A time-driven activity-based costing model for radiotherapy was developed. Resource cost calculation of all radiotherapy treatments, standard and innovative, was conducted in 10 Belgian radiotherapy centers in the second half of 2012. The average cost of lung SBRT across the 10 centers (6221&OV0556;) is in the range of the average costs of standard fractionated 3D-conformal radiotherapy (5919&OV0556;) and intensity-modulated radiotherapy (7379&OV0556;) for lung cancer. Hypofractionated 3D-conformal radiotherapy and intensity-modulated radiotherapy schemes are less costly (3993&OV0556; respectively 4730&OV0556;). The SBRT cost increases with the number of fractions and is highly dependent of personnel and equipment use. SBRT cost varies more by centre than conventional radiotherapy cost, reflecting different technologies, stages in the learning curve and a lack of clear guidance in this field. Time-driven activity-based costing of radiotherapy is feasible in a multicentre setup, resulting in real-life resource costs that can form the basis for correct reimbursement schemes, supporting an early yet controlled introduction of innovative radiotherapy techniques in clinical practice.

  4. TU-H-BRC-07: Therapeutic Benefit in Spatially Fractionated Radiotherapy (GRID) Using Helical Tomotherapy

    International Nuclear Information System (INIS)

    Narayanasamy, G; Zhang, X; Paudel, N; Morrill, S; Maraboyina, S; Peacock, L; Penagaricano, J; Meigooni, A; Liang, X

    2016-01-01

    Purpose: The aim of this project is to study the therapeutic ratio (TR) for helical Tomotherapy (HT) based spatially fractionated radiotherapy (GRID). Estimation of TR was based on the linear-quadratic cell survival model by comparing the normal cell survival in a HT GRID to that of a uniform dose delivery in an open-field for the same tumor survival. Methods: HT GRID plan was generated using a patient specific virtual GRID block pattern of non-divergent, cylinder shaped holes using MLCs. TR was defined as the ratio of normal tissue surviving fraction (SF) under HT GRID irradiation to an open field irradiation with an equivalent dose that result in the same tumor cell SF. The ratio was estimated from DVH data on ten patient plans with deep seated, bulky tumor approved by the treating radiation oncologist. Dependence of the TR values on radio-sensitivity of the tumor cells and prescription dose were also analyzed. Results: The mean ± standard deviation (SD) of TR was 4.0±0.7 (range: 3.1 to 5.5) for the 10 patients with single fraction dose of 20 Gy and tumor cell SF of 0.5 at 2 Gy. In addition, mean±SD of TR = 1±0.1 and 18.0±5.1 were found for tumor with SF of 0.3 and 0.7, respectively. Reducing the prescription dose to 15 and 10 Gy lowered the TR to 2.0±0.2 and 1.2±0.04 for a tumor cell SF of 0.5 at 2 Gy. In this study, the SF of normal cells was assumed to be 0.5 at 2 Gy. Conclusion: HT GRID displayed a significant therapeutic advantage over uniform dose from an open field irradiation. TR increases with the radioresistance of the tumor cells and with prescription dose.

  5. Fractionated radiosurgery for painful spinal metastases: DOSIS - a phase II trial

    International Nuclear Information System (INIS)

    Guckenberger, Matthias; Hawkins, Maria; Flentje, Michael; Sweeney, Reinhart A

    2012-01-01

    One third of all cancer patients will develop bone metastases and the vertebral column is involved in approximately 70% of these patients. Conventional radiotherapy with of 1–10 fractions and total doses of 8-30 Gy is the current standard for painful vertebral metastases; however, the median pain response is short with 3–6 months and local tumor control is limited with these rather low irradiation doses. Recent advances in radiotherapy technology – intensity modulated radiotherapy for generation of highly conformal dose distributions and image-guidance for precise treatment delivery – have made dose-escalated radiosurgery of spinal metastases possible and early results of pain and local tumor control are promising. The current study will investigate efficacy and safety of radiosurgery for painful vertebral metastases and three characteristics will distinguish this study. 1) A prognostic score for overall survival will be used for selection of patients with longer life expectancy to allow for analysis of long-term efficacy and safety. 2) Fractionated radiosurgery will be performed with the number of treatment fractions adjusted to either good (10 fractions) or intermediate (5 fractions) life expectancy. Fractionation will allow inclusion of tumors immediately abutting the spinal cord due to higher biological effective doses at the tumor - spinal cord interface compared to single fraction treatment. 3) Dose intensification will be performed in the involved parts of the vertebrae only, while uninvolved parts are treated with conventional doses using the simultaneous integrated boost concept. It is the study hypothesis that hypo-fractionated image-guided radiosurgery significantly improves pain relief compared to historic data of conventionally fractionated radiotherapy. Primary endpoint is pain response 3 months after radiosurgery, which is defined as pain reduction of ≥ 2 points at the treated vertebral site on the 0 to 10 Visual Analogue Scale. 60 patients

  6. Clinical Impact of Re-irradiation with Carbon-ion Radiotherapy for Lymph Node Recurrence of Gynecological Cancers.

    Science.gov (United States)

    Shiba, Shintaro; Okonogi, Noriyuki; Kato, Shingo; Wakatsuki, Masaru; Kobayashi, Daijiro; Kiyohara, Hiroki; Ohno, Tatsuya; Karasawa, Kumiko; Nakano, Takashi; Kamada, Tadashi

    2017-10-01

    To evaluate the safety and efficacy of re-irradiation with carbon-ion radiotherapy (C-ion RT) for lymph node recurrence of gynecological cancers after definitive radiotherapy. Data regarding patients with unresectable and isolated recurrent lymph node from gynecological cancer after definitive radiotherapy were analyzed. Total dose of C-ion RT was 48-57.6 Gy (RBE) in 12 or 16 fractions. Sixteen patients received re-irradiation by C-ion RT were analyzed. Median follow-up was 37 months. Median tumor size was 27 mm. None developed Grade 1 or higher acute toxicities and Grade 3 or higher late toxicities. The 3-year overall survival, local control and disease-free survival rates after C-ion RT were 74%, 94% and 55%, respectively. Re-irradiation with C-ion RT for lymph node recurrence of gynecological cancers after definitive radiotherapy can be safe and effective. This result suggested that C-ion RT could be a curative treatment option for conventionally difficult-to-cure patients. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  7. Differences in Clinical Results After LINAC-Based Single-Dose Radiosurgery Versus Fractionated Stereotactic Radiotherapy for Patients With Vestibular Schwannomas

    International Nuclear Information System (INIS)

    Combs, Stephanie E.; Welzel, Thomas; Schulz-Ertner, Daniela; Huber, Peter E.; Debus, Juergen

    2010-01-01

    Purpose: To evaluate the outcomes of patients with vestibular schwannoma (VS) treated with fractionated stereotactic radiotherapy (FSRT) vs. those treated with stereotactic radiosurgery (SRS). Methods and Materials: This study is based on an analysis of 200 patients with 202 VSs treated with FSRT (n = 172) or SRS (n = 30). Patients with tumor progression and/or progression of clinical symptoms were selected for treatment. In 165 out of 202 VSs (82%), RT was performed as the primary treatment for VS, and for 37 VSs (18%), RT was conducted for tumor progression after neurosurgical intervention. For patients receiving FSRT, a median total dose of 57.6 Gy was prescribed, with a median fractionation of 5 x 1.8 Gy per week. For patients who underwent SRS, a median single dose of 13 Gy was prescribed to the 80% isodose. Results: FSRT and SRS were well tolerated. Median follow-up time was 75 months. Local control was not statistically different for both groups. The probability of maintaining the pretreatment hearing level after SRS with doses of ≤13 Gy was comparable to that of FSRT. The radiation dose for the SRS group (≤13 Gy vs. >13 Gy) significantly influenced hearing preservation rates (p = 0.03). In the group of patients treated with SRS doses of ≤13 Gy, cranial nerve toxicity was comparable to that of the FSRT group. Conclusions: FSRT and SRS are both safe and effective alternatives for the treatment of VS. Local control rates are comparable in both groups. SRS with doses of ≤13 Gy is a safe alternative to FSRT. While FSRT can be applied safely for the treatment of VSs of all sizes, SRS should be reserved for smaller lesions.

  8. Radiotherapy for stage IV oropharyngeal cancer

    International Nuclear Information System (INIS)

    Nakamura, Kaori; Akimoto, Tetsuo; Motegi, Atsushi

    2008-01-01

    Fifty-seven patients with stage IVA-B oropharyngeal cancer treated by definitive radiotherapy in our facility from January 1993 to August 2005 were retrospectively analyzed. The age of the patients was 34-84 (median 62) years old. Thirty-four were male and 14 were female. Subsite of the tumor was anterior: 16, lateral: 39, posterior: 1, and superior: 1. Forty-nine patients were treated with chemotherapy. Induction chemotherapy (ICT) was done in 25 patients, ICT+concurrent chemoradiotherapy (CCRT) in 15 patients, and CCRT in 9 patients. A dose of 60-82 Gy (median 72 Gy) by hyperfractionated radiotherapy, at 1.2 Gy/fraction twice a day, was delivered in 37 patients, and 60-72 Gy (median 66 Gy) with a conventional daily fractionation in 20 patients. Salvage surgery was performed in 5 patients as a part of primary treatment after radiotherapy. The 5-year cause-specific survival rate and disease-free survival rate were 52.9% and 51.4%, respectively. By univariate analysis, the impact of age, sex, T-stage, N-stage, histological differentiation, chemotherapy and fractionation of radiation therapy on survivals were evaluated. T-stage, N-stage and histological differentiation were significantly covariate correlated with survival. The treatment results were not satisfactory. Further investigation of the treatment strategy to improve the treatment outcome of advanced oropharyngeal cancer is desired. (author)

  9. Comparing the effects of conventional and hypofractionated radiotherapies on early skin toxicity and cosmetic outcomes after breast cancer conserving surgery

    Directory of Open Access Journals (Sweden)

    Amouzegar Hashemi F

    2012-12-01

    Full Text Available Background: The high number of breast cancer patients who receive radiation therapy after surgery has caused many to think about a shorter period of radiotherapy, which can significantly reduce the radiotherapy machine time, labor hours, and fewer patient visits. This study was designed to evaluate the acute skin effects and cosmetic outcomes of short course radiotherapy in early-stage breast cancer in comparison with the conventional treatment method.Methods: Fifty-two patients with operable breast cancer (pT1-3pN0M0 who underwent breast conservation surgery in Tehran Cancer Institute during January 2011 to January 2012, were randomly assigned to undergo radiotherapy by either receiving conventional treatment (dose: 50 Gy in 25 fractions with subsequent electron boost or a short-course hypofractionated radiotherapy (dose: 42.5 Gy in 16 fractions and a subsequent electron boost.Results: There were no skin changes during the first or the second week of treatment in the two groups. Cutaneous complications began after the third week as grade 1 skin toxicity after termination of the short-course radiotherapy but there were no difference in complication rate after four weeks of treatment. Six months and one year after treatment, there were no differences in terms of skin complications or cosmetic outcomes between the two groups.Conclusion: Although the use of a whole-breast irradiation with a hypofractionated schedule was associated with desirable outcomes, in term of skin toxicity and cosmetics, but longer follow-up periods with larger sample sizes are needed to confirm these results.

  10. Randomized trial of single dose versus fractionated palliative radiotherapy of bone metastases

    International Nuclear Information System (INIS)

    Nielsen, O.S.; Bentzen, S.M.; Sandberg, E.; Gadeberg, C.C.; Timothy, A.R.

    1998-01-01

    Purpose: Data in the literature suggest that for painful bone metastases a single dose is as effective as fractionated radiotherapy. In the present multicentre prospective trial, the effects of 8 Gy x1 and 5 Gy x4 were compared. Patients and methods: A total of 241 patients were randomized to 8 Gy (122 patients) or 20 Gy (119 patients). The primary tumour was in the breast in 39% of patients, in the prostate in 34% of patients, in the lung in 13% of patients and in other locations in 14% of patients. Outcome measures were pain relief as measured by VAS and in half of the patients also by a five-point categorical pain scale, global quality of life (QoL) and analgesic consumption. Evaluation was performed before and 4, 8, 12 and 20 weeks after treatment. Results: A total of 239 patients were evaluable for response. The two groups did not differ with respect to age, sex, primary tumour, metastasis localization, analgesic consumption (type and dose), performance status, prior systemic treatment, degree of pain and QoL. The treatment was completed as planned in 98% of patients. The degree of pain relief did not differ between the two treatment groups. At 4 weeks the difference in pain relief was 6% (95% CI 7, 20%) and at 8 weeks the difference was 13% (95% CI 3, 28%). Neither was there any significant difference in the duration of pain relief, the number of new painful sites and the need for reirradiation and toxicity was minor. Conclusion: The present randomized study showed that a single fraction of 8 Gy was as effective as 5 Gy x4 in relieving pain from bone metastasis. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Radiotherapy-induced emesis. An overview

    Energy Technology Data Exchange (ETDEWEB)

    Feyer, P.; Buchali, A.; Hinkelbein, M.; Budach, V. [Department Radiotherapy, Humboldt-University Berlin (Germany); Zimmermann, J.S. [Department Radiotherapy, Christian Albrechts-University Kiel (Germany); Titlbach, O.J. [Department of Medicine I, Hospital Friedrichshain, Berlin (Germany)

    1998-11-01

    Background: A significant number of patients receiving radiotherapy experience the distressing side effects of emesis and nausea. These symptoms are some of the most distressing problems for the patients influencing their quality of life. Methods: International study results concerning radiotherapy-induced emesis are demonstrated. A German multicenter questionnaire examining the strategies to prevent or to treat radiotherapy-induced nausea and emesis is presented. An international analysis concerning incidence of emesis and nausea in fractionated radiotherapy patients is discussed. Finally the consensus of the consensus conference on antiemetic therapy from the Perugia International Cancer Conference V is introduced. Results: Untreated emesis can lead to complications like electrolyte disorders, dehydration, metabolic disturbances and nutrition problems with weight loss. Prophylactic antiemetics are often given to patients receiving single high-dose radiotherapy to the abdomen. A survey has revealed that antiemetic prophylaxis is not routinely offered to the patients receiving fractionated radiotherapy. However, there is a need for an effective treatment of emesis for use in this group of patients, too. In 20% of patients nausea and emesis can cause a treatment interruption because of an inadequate control of symptoms. Like in chemotherapy strategies there exist high, moderate, and low emetogenic treatment regimens in radiotherapy as well. The most emetogenic potential has the total body irradiation followed by radiotherapy to the abdomen. Radiotherapy induced emesis can be treated effectively with conventional antiemetics up to 50%. Conclusions: Studies with total body irradiation, fractionated treatment and high-dose single exposures have cleary demonstrated the value of 5-HT3-receptor antagonist antiemetics. There is a response between 60 and 97%. There is no difference in the efficacy of the different 5-HT3-antagonists. High-risk patients should be prophylactic

  12. ACCELERATED REGIMENS OF ADJUVANT RADIOTHERAPY IN THE TREATMENT OF BREAST CANCER

    Directory of Open Access Journals (Sweden)

    G. V. Afonin

    2017-01-01

    Full Text Available Treatment of breast cancer (BC is a complex multidisciplinary problem. Often, radiation therapy is an obligatory component of treatment of breast cancer patients. Numerous large randomized trials have proved the efficacy of adjuvant radiotherapy in both the standard fractionation regimen in a single focal dose of 2 Gy to a total focal dose of 50 Gy for 25 fractions and in modes of hypofractionation using radiation exposure at a larger daily dose with a reduction in the total treatment time. The presented review summarizes the data of the largest studies on the modes of hypofractionation of postoperative radiotherapy for breast cancer. Most of the studies comparing the standard mode of fractionation of postoperative radiotherapy with the modes of hypofractionation showed comparable results for the main oncological parameters with similar tolerability, frequency of complications and good cosmetic results. It also shows the economic feasibility of applying accelerated regimes in everyday practice. Despite the fact that radiotherapy in the mode of hypofractionation has already become the standard of treatment and is recommended for use by the largest European and American cancer associations, indications for its conduct, the criteria for selection in the studies and the range of recommended single focal doses differ. The obtained results do not give an opportunity to confidently judge the advantage of one or another regime. It is necessary to determine the factors of a favorable and unfavorable prognosis, to clarify the indications for the use of various radiotherapy techniques. Therefore, questions about the optimal mode of hypo-fractionation of adjuvant radiotherapy, the timing of its initiation and the criteria for selecting patients for this type of therapy as part of the comprehensive treatment of breast cancer have not yet been fully resolved. Also open is the choice of optimal single and total doses of radiation, its combination with drug

  13. A technique of using gated-CT images to determine internal target volume (ITV) for fractionated stereotactic lung radiotherapy

    International Nuclear Information System (INIS)

    Jin Jianyue; Ajlouni, Munther; Chen Qing; Yin, Fang-Fang; Movsas, Benjamin

    2006-01-01

    Background and purpose: To develop and evaluate a technique and procedure of using gated-CT images in combination with PET image to determine the internal target volume (ITV), which could reduce the planning target volume (PTV) with adequate target coverage. Patients and methods: A skin marker-based gating system connected to a regular single slice CT scanner was used for this study. A motion phantom with adjustable motion amplitude was used to evaluate the CT gating system. Specifically, objects of various sizes/shapes, considered as virtual tumors, were placed on the phantom to evaluate the number of phases of gated images required to determine the ITV while taking into account tumor size, shape and motion. A procedure of using gated-CT and PET images to define ITV for patients was developed and was tested in patients enrolled in an IRB approved protocol. Results: The CT gating system was capable of removing motion artifacts for target motion as large as 3-cm when it was gated at optimal phases. A phantom study showed that two gated-CT scans at the end of expiration and the end of inspiration would be sufficient to determine the ITV for tumor motion less than 1-cm, and another mid-phase scan would be required for tumors with 2-cm motion, especially for small tumors. For patients, the ITV encompassing visible tumors in all sets of gated-CT and regular spiral CT images seemed to be consistent with the target volume determined from PET images. PTV expanded from the ITV with a setup uncertainty margin had less volume than PTVs from spiral CT images with a 10-mm generalized margin or an individualized margin determined at fluoroscopy. Conclusions: A technique of determining the ITV using gated-CT images was developed and was clinically implemented successfully for fractionated stereotactic lung radiotherapy

  14. Comparison of long-term survival and toxicity of simultaneous integrated boost vs conventional fractionation with intensity-modulated radiotherapy for the treatment of nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Tao HM

    2016-03-01

    Full Text Available Hengmin Tao,1,2 Yumei Wei,1 Wei Huang,1 Xiujuan Gai,1,2 Baosheng Li11Department of 6th Radiation Oncology, Shandong Cancer Hospital and Institute, 2School of Medicine and Life Sciences, Jinan University-Shandong Academy of Medical Sciences, Jinan, People’s Republic of ChinaAim: In recent years, the intensity-modulated radiotherapy with simultaneous integrated boost (IMRT-SIB and intensity-modulated radiotherapy with conventional fractionation (IMRT-CF have been involved in the treatment of nasopharyngeal carcinoma (NPC. However, the potential clinical effects and toxicities are still controversial.Methods: Here, 107 patients with biopsy-proven locally advanced NPC between March 2004 and January 2011 were enrolled in the retrospective study. Among them, 54 patients received IMRT-SIB, and 53 patients received IMRT-CF. Subsequently, overall survival (OS, 5-year progression-free survival (PFS, 5-year locoregional recurrence-free survival (LRFS, and relevant toxicities were analyzed.Results: In the present study, all patients completed the treatment, and the overall median follow-up time was 80 months (range: 8–126 months. The 5-year OS analysis revealed no significant difference between the IMRT-SIB and IMRT-CF groups (80.9% vs 80.5%, P=0.568. In addition, there were also no significant between-group differences in 5-year PFS (73.3% vs 74.4%, P=0.773 and 5-year LRFS (88.1% vs 90.8%, P=0.903. Notably, the dose to critical organs (spinal cord, brainstem, and parotid gland in patients treated by IMRT-CF was significantly lower than that in patients treated by IMRT-SIB (all P<0.05.Conclusion: Both IMRT-SIB and IMRT-CF techniques are effective in treating locally advanced NPC, with similar OS, PFS, and LRFS. However, IMRT-CF has more advantages than IMRT-SIB in protecting spinal cord, brainstem, and parotid gland from acute and late toxicities, such as xerostomia. Further prospective study is warranted to confirm our findings.Keywords: intensity

  15. Prior surgical intervention and tumor size impact clinical outcome after precision radiotherapy for the treatment of optic nerve sheath meningiomas (ONSM)

    International Nuclear Information System (INIS)

    Adeberg, Sebastian; Welzel, Thomas; Rieken, Stefan; Debus, Jürgen; Combs, Stephanie E

    2011-01-01

    We analyzed our long-term experience with fractionated stereotactic radiotherapy (FSRT) in patients with meningioma of the optic nerve sheath (ONSM). Between January 1991 and January 2010, 40 patients with ONSM were treated using FSRT. Of these, 19 patients received radiotherapy as primary treatment, and 21 patients were treated after surgical resection. The median target volume was 9.2 ml, median total dose was 54 Gy in median single fractions of 1,8 Gy. Local progression-free survival was 100%. Median survival after FSRT was 60 months (range 4-228 months). In all patients overall toleration of FSRT was very good. Acute toxicity was mild. Prior to RT, 29 patients complained about any kind of visual impairment including visual field deficits, diplopia or amaurosis. Prior surgical resection was identified as a negative prognostic factor for visual outcome, whereas patients with larger tumor volumes demonstrated a higher number of patients with improvement of pre-existing visual deficits. Long-term outcome after FSRT for ONSM shows improved vision in patients not treated surgically prior to RT; moreover, the best improvement of visual deficits are observed in patients with larger target volumes. The absence of tumor recurrences supports that FSRT is a strong alternative to surgical resection especially in small tumors without extensive compression of normal tissue structures

  16. Functional groups and reactivity of size-fractionated Aldrich humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Tadao, E-mail: tanaka.tadao26@jaea.go.jp [Nuclear Safety Research Center, Japan Atomic Energy Agency, Shirakata 2-4, Tokai, Naka, Ibaraki, 319-1195 (Japan)

    2012-03-20

    The complexation affinity of the Aldrich Chemicals humic acid with {sup 60}Co was examined with respect to molecular size of humic acid. Correlations between the affinity and the structures of humic acid were studied. At low humic acid concentration range, {sup 60}Co was interacted with the humic acid of size fraction over 100k Da (HA(100<)). With increasing humic acid concentration, the {sup 60}Co was preferentially interacted with the 30k-100k Da of humic acid (HA(30-100)). Fractionated HA(100<) and HA(30-100) were characterized from their FTIR (Fourier Transform Infra-Red), {sup 13}C NMR spectral analyses and acid-base titration curves. The HA(10<) having aliphatic branched structure, smaller amount of COOH group and large proton exchangeable capacity, seem to show low covalent bonding nature and high ion exchangeability in the complexation. In addition, steric hindrance may affect on the complexation, by winding up like random coils from the branched structure. The HA(30-100) is dominated with the aromatic COOH group and OH group and it may preferentially coordinate to {sup 60}Co by covalent binding. These presumptions were supported by XPS analysis, in which the biding energy of cobalt-humates was discussed.

  17. Bacterial Preferences for Specific Soil Particle Size Fractions Revealed by Community Analyses

    DEFF Research Database (Denmark)

    Hemkemeyer, Michael; Dohrmann, Anja B.; Christensen, Bent Tolstrup

    2018-01-01

    , while Gemmatimonadales preferred coarse silt, Actinobacteria and Nitrosospira fine silt, and Planctomycetales clay. Firmicutes were depleted in the sand-sized fraction. In contrast, archaea, which represented 0.8% of all 16S rRNA gene sequences, showed only little preference for specific PSFs. We...

  18. Doses to organs at cerebral risks: optimization by robotized stereotaxic radiotherapy and automatic segmentation atlas versus three dimensional conformal radiotherapy

    International Nuclear Information System (INIS)

    Bondiau, P.Y.; Thariat, J.; Benezery, K.; Herault, J.; Dalmasso, C.; Marcie, S.; Malandain, G.

    2007-01-01

    The stereotaxic radiotherapy robotized by 'Cyberknife fourth generation' allows a dosimetric optimization with a high conformity index on the tumor and radiation doses limited on organs at risk. A cerebral automatic anatomic segmentation atlas of organs at risk are used in routine in three dimensions. This study evaluated the superiority of the stereotaxic radiotherapy in comparison with the three dimensional conformal radiotherapy on the preservation of organs at risk in regard of the delivered dose to tumors justifying an accelerated hypo fractionation and a dose escalation. This automatic segmentation atlas should allow to establish correlations between anatomy and cerebral dosimetry; This atlas allows to underline the dosimetry optimization by stereotaxic radiotherapy robotized for organs at risk. (N.C.)

  19. HIV-associated cutaneous Kaposi's sarcoma - palliative local treatment by radiotherapy

    International Nuclear Information System (INIS)

    Saran, F.H.; Adamietz, I.A.; Thilmann, C.; Mose, S.; Boettcher, H.D.

    1997-01-01

    The increasing number of HIV-infected patients makes palliative treatment of HIV-associated Kaposi's sarcoma more common. We retrospectively evaluated a reduced fractionated radiotherapy with 20 Gy in respect to response rates and acute side-effects. From January 1992 to January 1995, 52 patients with HIV-associated Kaposi's sarcoma were treated with 133 single portals. Six weeks after the end of radiotherapy 42 patients with 124 portals were evaluable with respect to response rates and side-effects. Of the treated portals 32% were judged as complete responses (CR), 55% as partial responses (PR) and 12% as no change (NC). Skin reactions RTOG, grade 1 were seen in 74% of the patients. Compared with literature data the reduced overall dose of 20 Gy in 10 fractions led to a reduction of CRs by approximately 50% while the overall response rate remained equal. The success of radiotherapy for the nodular component of Kaposi's sarcoma can be improved, if a dose exceeding 20 Gy in 10 fractions is applied but at the cost of increasing side-effects in case that non-conventional fractionation schemes are used. (orig.)

  20. Whole-abdomen radiotherapy for non-Hodgkin's lymphoma using twice-daily fractionation

    International Nuclear Information System (INIS)

    Liauw, Stanley L.; Yeh, Alexander M.; Morris, Christopher G.; Olivier, Kenneth R.; Mendenhall, Nancy Price

    2006-01-01

    Purpose: To report the tolerability and efficacy of twice-daily whole-abdomen irradiation (WAI) for non-Hodgkin's lymphoma (NHL). Methods and Materials: Of 123 patients treated for NHL with WAI, 37% received previous chemotherapy, 28% received WAI as part of comprehensive lymphatic irradiation (CLI), and 32% received WAI for palliation. The median dose to the whole abdomen was 25.0 Gy, followed by a median tumor boost of 9.8 Gy in 58 patients. Fractionation was 1.0 Gy once daily (54%) or 0.8 Gy twice daily (46%). Blood counts were measured weekly. Results: At a median follow-up of 4.3 years, local control was 72% and overall survival was 55% at 5 years. Median time of WAI was 42 days for once-daily treatment and 32 days for twice-daily treatment. Patients receiving twice-daily WAI did not have a significantly higher rate of acute side effects (e.g., nausea, diarrhea, platelet or red blood cell toxicity). Overall, acute thrombocytopenia was the most frequent side effect of treatment; 24 of 96 patients (25%) with available hematologic data had Grade 3+ toxicity. There was no acute Grade 3 gastrointestinal toxicity and no late small bowel obstruction. Multiple regression indicated that patients with four or less involved sites and disease size ≤6 cm had improved local control and overall survival. Conclusions: Twice-daily WAI using 0.8 Gy/fraction does not appear to have any greater toxicity compared with once-daily treatment using 1 Gy/fraction. Small doses per fraction (0.8-1 Gy/fx) are effective, tolerated well in the acute setting, and associated with a low rate of late toxicity

  1. Radiotherapy of macular lesions in age-related macular degeneration (A.M.D.): preliminary results of a clinical study conducted in Lyon, France; Radiotherapie des degenerescences maculaires liees a l`age (DMLA): resultats preliminaires d`une etude lyonnaise

    Energy Technology Data Exchange (ETDEWEB)

    Martin, P. [Centre oncologie radiotherapie Saint-Jean, 69 - Lyon (France); Mauget, M. [Centre ophtalmologique d`imagerie, laser, 69 - Lyon (France); Gerard, J.P. [Service de radiotherapie-oncologie, CHU Lyon Sud, 69 - Pierre-Benite (France) (and others)

    1997-06-01

    To evaluate irradiation effects on functional signs and choroidal neo-vascular lesions in age-related macular degeneration (AMD) that does not respond to laser therapy. Since 1994, 250 consecutive AMD patients were treated by two radiotherapy teams for sub-foveal neo-vascular lesions. At the end of september 1996, 52 patients were evaluable with a 1-year follow-up. Group 1 (Department de Radiotherapie Oncologie, Centre Hospitalo-Universitaire Lyon Sud) included 26 patients who were treated with a lateral beam of 6 MV photons. The irradiation dose were 20 Gy in five fractions for small lesions and 28.8 Gy in eight fractions for larger lesions. Group 2 (Centre Oncologie Radiotherapie Saint-Jean) was composed of 26 patients treated with a mini-beam of 25 MV photons via lateral arc-therapy. Beam diameters (14 and 18 mm) were adapted to the lesion size. The total dose was 16 Gy in four fractions or 20 Gy in five fractions. Functional and anatomical results were assessed at 3, 6, 9 months and 1 year after radiation therapy. Stable visual acuity was observed in 44 % (23/52) of the patients and visual acuity was improved in 35 % (18/52) of the patients at 6 months. Good functional results reached 79 % (41/52) at 6 months and 74 % (17/23) at 12 months. There was no statistical difference between the two groups and dose levels. All severe complications (1 cataract, 3 dilated choroidal vessels, and 2 papillitis) occurred in group 1. Though it is too early to conclude on the best dose level, radiotherapy of sub-foveal neo-vascular lesions of AMD that cannot be treated via laser therapy provides encouraging results. The technique used must be very precise to adequately irradiate the fovea and spare surrounding sensitive areas. Further studies and trials involving patients` randomization are necessary to confirm these preliminary results. (author) 13 refs.

  2. Late regional density changes of the lung after radiotherapy for breast cancer

    International Nuclear Information System (INIS)

    Vagane, Randi; Danielsen, Turi; Fossa, Sophie Dorothea; Lokkevik, Erik; Olsen, Dag Rune

    2009-01-01

    Background and purpose: To investigate density changes in lung tissue, 3-4 years after postoperative adjuvant radiotherapy for breast cancer, based on dose dependence and regional differences. Material and methods: Sixty-one breast cancer patients, who had received computed tomography (CT) based postoperative radiotherapy, were included. CT scans were performed 35-51 months after start of radiotherapy. Dose information and CT scans from before and after radiotherapy were geometrically aligned in order to analyse changes in air-filled fraction (derived from CT density) as a function of dose for different regions of the lung. Results: Dose-dependent reduction of the air-filled fraction was shown to vary between the different regions of the lung. For lung tissue receiving about 50 Gy, the largest reduction in air-filled fraction was found in the cranial part of the lung. An increased air-filled fraction was observed for lung tissue irradiated to doses below 20 Gy, indicating compensatory response. Conclusions: The treatment-induced change in whole-lung density is a weighted response, involving the different regions, the irradiated volumes, and dose levels to these volumes. Simplistic models may therefore not be appropriate for describing the whole-lung dose-volume-response relationship following inhomogeneous irradiation

  3. 188Re-microspheres of albumin - the potential preparation for radiotherapy

    International Nuclear Information System (INIS)

    Dyomin, D.N.; Petriev, V.M.

    2000-01-01

    In this paper author describe preparation the albumin microspheres labelled with rhenium-188. We undertake an attempt to develop kits to the generator of rhenium-188 on the basis of albumin microspheres for radiotherapy of both oncological and non-oncological diseases. Microspheres, rhenium-188 with sizes 1 0-20 micron for treatment of rheumatoid arthritis (damage of large and intermediate joints), intraperitoneal administration and intrapleural administration at metastases covering a cavity. Microspheres, Re-188 with sizes 40-60 micron for treatment of disseminated kidney cancer (intraarterial, selectively), intratumoral administration to damaged nodules less than 2-3 cm. Microspheres, Re-188 with sizes 80-100 micron for large neoplasms and metastases of liver (intraarterial, selectively), intratumoral administration to damaged nodules with sizes over 3 cm. Preparation of albumin microspheres is carried out by thermal denaturation of protein in vegetable oil. Microspheres are obtained with the necessary range of sizes by ultrasonic fractionation. At our laboratory the method of preparation of albumin microspheres with any sizes of particles (from 5 -10 up to 800 -1000 microns) has been developed. (authors)

  4. Dosimetry comparison of irradiation with conformal radiotherapy, intensity modulated radiotherapy, conformal radiotherapy in stereotactic conditions and robotic stereotactic radiotherapy for benign brain tumours

    International Nuclear Information System (INIS)

    Spasic, E.; Noel, A.; Buchheit, I.; Bernier, V.

    2011-01-01

    Purpose. - To compare several techniques in order to determine the best treatment for benign brain tumours. Methods and patients. - A retrospective study was performed for five patients who received 3D-conformal radiotherapy, intensity modulated radiotherapy or CyberKnife R . These patients had a meningioma, a pituitary tumour, a cranio-pharyngioma or a neurinoma. In each case, these treatment plans were optimised and compared with the three other dosimetries. Radiobiological or positioning parameters were evaluated, as well as dosimetric parameters, in order to compare treatments with different characteristics. Results. - The dosimetric parameters showed that the choice of treatment seemed to be determined mostly by tumour size, shape and proximity with organs at risk (not tumour localisation). Whereas the results showed no significant deviations with regards to the radiobiological parameters. Therefore, with these parameters, it was difficult to give priority to a treatment. Conclusions. - With regards to benign brain tumours of medium or large size, intensity modulated radiotherapy seemed the recommended treatment. It enabled to obtain a good ratio between efficacy and toxicity for tumours that are really close to organs at risk. Concerning small benign brain tumours, the CyberKnife R was probably the best treatment. (authors)

  5. Efficacy and toxicity of (chemo)radiotherapy for primary subglottic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hata, M.; Koike, I.; Odagiri, K.; Minagawa, Y.; Inoue, T. [Yokohama City Univ. Graduate School of Medicine, Yokohama (Japan). Dept. of Radiology; Taguchi, T.; Nishimura, G.; Takahashi, M.; Komatsu, M.; Sano, D. [Yokohama City Univ. Graduate School of Medicine, Yokohama (Japan). Dept. of Otorhinolaryngology

    2013-01-15

    Background and purpose: Primary subglottic cancer is a rare malignancy. We investigated the efficacy and toxicity of radiotherapy for subglottic cancer. Patients and methods: Nineteen patients with primary squamous cell carcinoma of the subglottis received radiotherapy, 14 of whom also underwent chemotherapy. Of the 19 patients, 15 received definitive radiotherapy to the gross tumors with total doses of 70-70.2 Gy in 35-39 fractions, and 4 underwent preoperative radiotherapy with total doses of 37.8-55.8 Gy in 21-31 fractions, followed by total laryngectomy. Results: Of the 19 patients, 5 developed local progression and 2 developed distant metastasis at the median follow-up period of 5 years. The 5-year local control and disease-free rates were 74 and 63%, respectively. Three patients died of tumor progression, and the 5-year overall and disease-free survival rates were 80 and 63%, respectively. Regarding acute toxicities, transient mucositis and dermatitis of grade 3 or lower were observed in all patients, but there were no late toxicities of grade 3 or higher. Conclusion: Radiotherapy is a safe and effective treatment for patients with primary squamous cell carcinoma of the subglottis. The use of chemotherapy together with radiotherapy may enhance treatment efficacy and contribute to larynx preservation through good local control. (orig.)

  6. Radical hypo-fractionated radiotherapy with volumetric modulated arc therapy in lung cancer. A retrospective study of elderly patients with stage III disease

    Energy Technology Data Exchange (ETDEWEB)

    Franceschini, D. [Humanitas Cancer Center and Research Hospital, Radiotherapy and Radiosurgery Department, Milan (Italy); Istituto Clinico Humanitas Cancer Center, Rozzano (Milan) (Italy); De Rose, F.; Navarria, P.; Clerici, E.; Franzese, C.; Comito, T.; Tozzi, A.; Iftode, C.; D' Agostino, G. [Humanitas Cancer Center and Research Hospital, Radiotherapy and Radiosurgery Department, Milan (Italy); Cozzi, L.; Sorsetti, M. [Humanitas Cancer Center and Research Hospital, Radiotherapy and Radiosurgery Department, Milan (Italy); Humanitas University, Department of Biomedical Sciences, Milan (Italy)

    2017-05-15

    This study aimed to analyse the feasibility and acute toxicity of radical hypo-fractionated radiotherapy (RT) for elderly patients with non-small-cell lung cancer (NSCLC). We conducted a retrospective evaluation of treatment with volumetric modulated arc therapy (VMAT) of elderly patients affected by stage III inoperable NSCLC. The dose prescription was 56 Gy in 20 fractions, 55 Gy in 22 fractions, or 50 Gy in 20 fractions. Target volume included only the primary lesion and the infiltrated lymph nodes. The primary end point was acute and late toxicity, while secondary end points were progression-free survival (PFS), and overall survival (OS). In all, 41 patients were included in this analysis. The mean age of the patients was 78.6 years, and 22 patients had staged IIIA while 19 patients had stage IIIB disease. All but one patient had pathological nodal involvement; 15 patients received chemotherapy before RT. Acute grade 1-2 toxicity was recorded in 25 (61%) patients. Late toxicity was recorded in 13 (32%) patients. No cases of G3 or G4 toxicity were recorded. Complete response was obtained in two (5%) patients, 26 (63%) showed a partial response, and two (5%) experience disease progression. At a mean follow-up of 9.9 months (range, 1.1-25.4), 17 patients had died from disease progression, one died from other causes, and 23 were alive. Median OS was 13.7 ± 1.5 months (95% CI: 10.7-16.7), OS at 12 and 18 months was 51.3 ± 9.5% and 35.1 ± 10.1%, respectively. Median PFS was 13.7 ± 2.3 months (95% CI: 9.1-18.2), and PFS at 12 and 18 months was 50.1 ± 9.9% and 38.9 ± 10.4%, respectively. Radical hypo-fractionated VMAT is a promising treatment for locally advanced NSCLC in the elderly. The use of hypo-fractionated radiotherapy for lung cancer in older patients can be considered a valuable approach, particularly for patients with poor performance status or refusing other treatment approaches. (orig.) [German] Durchfuehrbarkeit und Nebenwirkungen der radikalen

  7. Large breast size as a risk factor for late adverse effects of breast radiotherapy: Is residual dose inhomogeneity, despite 3D treatment planning and delivery, the main explanation?

    International Nuclear Information System (INIS)

    Goldsmith, Christy; Haviland, Joanne; Tsang, Yat; Sydenham, Mark; Yarnold, John

    2011-01-01

    Background and Purpose: Large breast size is associated with an increased risk of late adverse effects after breast conservation surgery and radiotherapy, even when 3D dosimetry is used. The purpose of this study is to test the hypothesis that residual dose inhomogeneity is sufficient to explain the association. Methods: Patients previously treated after breast conservation surgery with whole breast radiotherapy using 3D dosimetry and followed up in the UK FAST hypofractionation trial were selected for this analysis. The residual level of dose inhomogeneity across the whole breast treatment volume was used to test for association between residual dosimetry and post-treatment change in breast appearance at 2 years post-radiotherapy. Results: At 2 years, 201/279 (72%) of women had no change in photographic breast appearance, 61 (22%) had mild change and 17 (6%) had marked change. Breast size and dosimetry were both significantly associated with late effects in univariate analyses, but only breast size remained an independent significant risk factor for change in breast appearance when included in a multiple regression model together with other prognostic factors (p = 0.006 for trend). Conclusion: Large-breasted women are more likely to suffer change in breast size and shape after whole breast radiotherapy delivered using 3D dosimetry, but residual dose inhomogeneity is insufficient to explain the association.

  8. The influence of dose per fraction on repair kinetics

    International Nuclear Information System (INIS)

    Rojas, A.; Joiner, M.C.

    1989-01-01

    The use of multiple fractions per day (MFD) in radiotherapy requires information about the rate of repair of radiation injury. It is important to know the minimum interval between fractions necessary for maximum sparing of normal tissue damage, whether rate of repair is dependent on the size of dose per fraction and if it is different in early and late responding tissues and in tumours. To address these questions, the rate of repair between radiation dose fractions was measured in mouse skin (acute damage), mouse kidney (late damage) and a mouse tumour (carcinoma NT). Skin and kidney measurements were made using multiple split doses of X-rays, followed by a neutron top-up. For skin, faster recovery was obtained with 4.4 Gy fractions (t1/2 = 3.46 ± 0.88 h). In contrast kidney showed slower recovery at a low dose per fraction of 2 Gy (t1/2 = 1.69 ± 0.39 h) than at a higher dose of 7 Gy per fraction (t1/2 = 0.92 ± 0.1h). These data show that repair rate is dependent on the size of dose per fraction, but not in a simple way. T1/2 values now available for many different tissues generally lie in the range of 1-2h, and are not correlated with proliferation status or early versus late response to treatment. At the doses used currently in clinical MFD treatments, these data indicate that damage in almost all normal tissues would increase if interfraction intervals less than 6 h were used. The t1/2 for CaNT (0.31 ± 0.15 h) is less than for any normal tissue. This underlines that the excess morbidity resulting from interfraction intervals < 6 h will not be paralleled by an increased effect in tumours. (author). 25 refs.; 7 figs

  9. Compliance to the prescribed dose and overall treatment time in five randomized clinical trials of altered fractionation in radiotherapy for head-and-neck carcinomas

    International Nuclear Information System (INIS)

    Khalil, Azza A.; Bentzen, Soeren M.; Bernier, Jacques; Saunders, Michele I.; Horiot, Jean-Claude; Bogaert, Walter van den; Cummings, Bernard J.; Dische, Stanley

    2003-01-01

    Purpose: To investigate compliance to the prescribed dose-fractionation schedule in five randomized controlled trials of altered fractionation in radiotherapy for head-and-neck carcinoma. Methods and Materials: Individual patient data from 2566 patients participating in the European Organization for Research and Treatment of Cancer (EORTC) 22791, EORTC 22811, EORTC 22851, Princess Margaret Hospital (PMH), and continuous hyperfractionated accelerated radiotherapy (CHART) head-and-neck trials were merged in the fractionation IMPACT (Intergroup Merger of Patient data from Altered or Conventional Treatment schedules) study database. The ideal treatment time was defined as the minimum time required to deliver a prescribed schedule. Compliance to the prescribed overall treatment time was quantified as the difference between the actual and the ideal overall time. An overall measure of compliance in an individual patient, the total dose lost (TDL), was calculated as the dose lost due to prolongation of therapy (assuming a D prolif of 0.64 Gy/day) plus the difference between the prescribed and the actual dose given. Results: The time in excess of the ideal ranged up to 97 days (average 3.9 days), and 25% of the patients had delays of 6 days or more. World Health Organization (WHO) performance status and nodal stage had a significant effect on TDL. TDL was significantly higher in the conventional than in the altered arm of the EORTC 22851 and CHART trials. In the PMH trial, TDL was significantly higher in the hyperfractionation than in the conventional arm. Centers participating in the three EORTC trials varied significantly in their compliance. There was a significant improvement in compliance in patients treated more recently. Conclusions: Even in randomized controlled trials, compliance to the prescribed radiation therapy schedule may be relatively poor, especially after conventional fractionation. This affects the interpretation of the outcome of these trials

  10. Conventional external beam radiotherapy for central nervous system malignancies

    International Nuclear Information System (INIS)

    Halperin, E.C.; Burger, P.C.

    1985-01-01

    Fractionated external beam photon radiotherapy is an important component of the clinical management of malignant disease of the central nervous system. The practicing neurologist or neurosurgeon frequently relies on the consultative and treatment skills of a radiotherapist. This article provides a review for the nonradiotherapist of the place of conventional external beam radiotherapy in neuro-oncology. 23 references

  11. Palliative prostate radiotherapy for symptomatic advanced prostate cancer

    International Nuclear Information System (INIS)

    Din, Omar S.; Thanvi, Narottam; Ferguson, Catherine J.; Kirkbride, Peter

    2009-01-01

    Background and purpose: To report the results for the use of short-course palliative radiotherapy to the prostate for localised symptoms. Materials and methods: Fifty-eight patients were identified from radiotherapy records between 2003 and 2007. Data were collected retrospectively on patients' demographics, radiotherapy details and response. Symptoms and toxicity were scored, retrospectively, according to the following scale: 0 = no symptoms, 1 = mild symptoms, 2 = moderate symptoms, and 3 = severe symptoms. Results: All the 58 patients had advanced prostate carcinoma. The median age at radiotherapy was 76.6 years (range 54-91). Fifty-six patients (97%) had hormone refractory disease. Twenty-seven patients (47%) had evidence of metastatic disease. 20Gy in 5 fractions was the most commonly used fractionation. The most frequent baseline symptom was haematuria (54%). Eighty-nine percent (31/35) of the patients had a complete or partial resolution of symptoms at 4 months. Response rates for individual symptoms (including unknown responses) were: rectal symptoms (75%), pelvic pain (69%), urinary obstruction (54%) and haematuria (42%). A >50% reduction in PSA occurred in five patients. Toxicity was mild to moderate only and was self-limiting. Conclusion: Palliative radiotherapy to the prostate gland for local symptoms appears to be an effective means of palliation with minimal toxic side effects. Prospective studies are now required to assess its benefits in more detail.

  12. Particle size fractionation of paralytic shellfish toxins (PSTs): seasonal distribution and bacterial production in the St Lawrence estuary, Canada.

    Science.gov (United States)

    Michaud, S; Levasseur, M; Doucette, G; Cantin, G

    2002-10-01

    We determined the seasonal distribution of paralytic shellfish toxins (PSTs) and PST producing bacteria in > 15, 5-15, and 0.22-5 microm size fractions in the St Lawrence. We also measured PSTs in a local population of Mytilus edulis. PST concentrations were determined in each size fraction and in laboratory incubations of sub-samples by high performance liquid chromatography (HPLC), including the rigorous elimination of suspected toxin 'imposter' peaks. Mussel toxin levels were determined by mouse bioassay and HPLC. PSTs were detected in all size fractions during the summer sampling season, with 47% of the water column toxin levels associated with particles smaller than Alexandrium tamarense ( 15 microm size fraction, we estimated that as much as 92% of PSTs could be associated with particles other than A. tamarense. Our results stress the importance of taking into account the potential presence of PSTs in size fractions other than that containing the known algal producer when attempting to model shellfish intoxication, especially during years of low cell abundance. Finally, our HPLC results confirmed the presence of bacteria capable of autonomous PST production in the St Lawrence as well as demonstrating their regular presence and apparent diversity in the plankton. Copyright 2002 Elsevier Science Ltd.

  13. The effects of low-dose radiotherapy on fresh osteochondral allografts: An experimental study in rabbits

    Directory of Open Access Journals (Sweden)

    Uğur Gönç

    2016-10-01

    Conclusion: In osteochondral massive allograft transplantations, the immune reaction of the host could be precluded with radiotherapy, and the side-effects can be prevented by low-dose fractionated regimen. The total dose of fractionated radiotherapy for an immune suppression should be adjusted not to damage the cartilage tissue, but to avoid articular degeneration in the long term.

  14. Fractionation and protraction for radiotherapy of prostate carcinoma

    International Nuclear Information System (INIS)

    Brenner, David J.; Hall, Eric J.

    1999-01-01

    Purpose: To investigate whether current fractionation and brachytherapy protraction schemes for the treatment of prostatic cancer with radiation are optimal, or could be improved. Methods and Materials: We analyzed two mature data sets on radiotherapeutic tumor control for prostate cancer, one using EBRT and the other permanent seed implants, to extract the sensitivity to changes in fractionation of prostatic tumors. The standard linear-quadratic model was used for the analysis. Results: Prostatic cancers appear significantly more sensitive to changes in fractionation than most other cancers. The estimated α/β value is 1.5 Gy [0.8, 2.2]. This result is not too surprising as there is a documented relationship between cellular proliferative status and sensitivity to changes in fractionation, and prostatic tumors contain exceptionally low proportions of proliferating cells. Conclusions: High dose rate (HDR) brachytherapy would be a highly appropriate modality for treating prostate cancer. Appropriately designed HDR brachytherapy regimens would be expected to be as efficacious as low dose rate, but with added advantages of logistic convenience and more reliable dose distributions. Similarly, external beam treatments for prostate cancer can be designed using larger doses per fraction; appropriately designed hypofractionation schemes would be expected to maintain current levels of tumor control and late sequelae, but with reduced acute morbidity, together with the logistic and financial advantages of fewer numbers of fractions

  15. Radiotherapy for solitary plasmacytoma and multiple myeloma

    International Nuclear Information System (INIS)

    Schmaus, M.C.; Neuhof, D.

    2014-01-01

    Solitary plasmacytoma and multiple myeloma require a differentiated radiotherapy. The irradiation for plasmacytoma with an adequate total dose (medullary 40-50 Gy or extramedullary 50-60 Gy) leads to a high degree of local control with a low rate of side effects. In cases of multiple myeloma radiotherapy will achieve effective palliation, both in terms of recalcification as well as reduction of neurological symptoms and analgesia. In terms of analgesia the rule is the higher the single dose fraction the faster the reduction of pain. As part of a conditioning treatment prior to stem cell transplantation radiotherapy contributes to the establishment of a graft versus myeloma effect (GVM). (orig.) [de

  16. Fractionated radiosurgery for painful spinal metastases: DOSIS - a phase II trial

    Directory of Open Access Journals (Sweden)

    Guckenberger Matthias

    2012-11-01

    Full Text Available Abstract Background One third of all cancer patients will develop bone metastases and the vertebral column is involved in approximately 70% of these patients. Conventional radiotherapy with of 1–10 fractions and total doses of 8-30 Gy is the current standard for painful vertebral metastases; however, the median pain response is short with 3–6 months and local tumor control is limited with these rather low irradiation doses. Recent advances in radiotherapy technology – intensity modulated radiotherapy for generation of highly conformal dose distributions and image-guidance for precise treatment delivery – have made dose-escalated radiosurgery of spinal metastases possible and early results of pain and local tumor control are promising. The current study will investigate efficacy and safety of radiosurgery for painful vertebral metastases and three characteristics will distinguish this study. 1 A prognostic score for overall survival will be used for selection of patients with longer life expectancy to allow for analysis of long-term efficacy and safety. 2 Fractionated radiosurgery will be performed with the number of treatment fractions adjusted to either good (10 fractions or intermediate (5 fractions life expectancy. Fractionation will allow inclusion of tumors immediately abutting the spinal cord due to higher biological effective doses at the tumor - spinal cord interface compared to single fraction treatment. 3 Dose intensification will be performed in the involved parts of the vertebrae only, while uninvolved parts are treated with conventional doses using the simultaneous integrated boost concept. Methods / Design It is the study hypothesis that hypo-fractionated image-guided radiosurgery significantly improves pain relief compared to historic data of conventionally fractionated radiotherapy. Primary endpoint is pain response 3 months after radiosurgery, which is defined as pain reduction of ≥ 2 points at the treated

  17. Optical spectroscopy of radiotherapy and photodynamic therapy responses in normal rat skin shows vascular breakdown products

    Science.gov (United States)

    Teles de Andrade, Cintia; Nogueira, Marcelo S.; Kanick, Stephen C.; Marra, Kayla; Gunn, Jason; Andreozzi, Jacqueline; Samkoe, Kimberley S.; Kurachi, Cristina; Pogue, Brian W.

    2016-03-01

    Photodynamic therapy (PDT) and radiotherapy are non-systemic cancer treatment options with different mechanisms of damage. So combining these techniques has been shown to have some synergy, and can mitigate their limitations such as low PDT light penetration or radiotherapy side effects. The present study monitored the induced tissue changes after PDT, radiotherapy, and a combination protocol in normal rat skin, using an optical spectroscopy system to track the observed biophysical changes. The Wistar rats were treated with one of the protocols: PDT followed by radiotherapy, PDT, radiotherapy and radiotherapy followed by PDT. Reflectance spectra were collected in order to observe the effects of these combined therapies, especially targeting vascular response. From the reflectance, information about oxygen saturation, met-hemoglobin and bilirubin concentration, blood volume fraction (BVF) and vessel radius were extracted from model fitting of the spectra. The rats were monitored for 24 hours after treatment. Results showed that there was no significant variation in the vessel size or BVF after the treatments. However, the PDT caused a significant increase in the met-hemoglobin and bilirubin concentrations, indicating an important blood breakdown. These results may provide an important clue on how the damage establishment takes place, helping to understand the effect of the combination of those techniques in order to verify the existence of a known synergistic effect.

  18. Carbon storage of different soil-size fractions in Florida silvopastoral systems.

    Science.gov (United States)

    Haile, Solomon G; Nair, P K Ramachandran; Nair, Vimala D

    2008-01-01

    Compared with open (treeless) pasture systems, silvopastoral agroforestry systems that integrate trees into pasture production systems are likely to enhance soil carbon (C) sequestration in deeper soil layers. To test this hypothesis, total soil C contents at six soil depths (0-5, 5-15, 15-30, 30-50, 50-75, and 75-125 cm) were determined in silvopastoral systems with slash pine (Pinus elliottii) + bahiagrass (Paspalum notatum) and an adjacent open pasture (OP) with bahiagrass at four sites, representing Spodosols and Ultisols, in Florida. Soil samples from each layer were fractionated into three classes (250-2000, 53-250, and <53 microm), and the C contents in each were determined. Averaged across four sites and all depths, the total soil organic carbon (SOC) content was higher by 33% in silvopastures near trees (SP-T) and by 28% in the alleys between tree rows (SP-A) than in adjacent open pastures. It was higher by 39% in SP-A and 20% in SP-T than in open pastures in the largest fraction size (250-2000 microm) and by 12.3 and 18.8%, respectively, in the intermediate size fraction (53-250 microm). The highest SOC increase (up to 45 kg m(-2)) in whole soil of silvopasture compared with OP was at the 75- to 125-cm depth at the Spodosol sites. The results support the hypothesis that, compared with open pastures, silvopastures contain more C in deeper soil layers under similar ecological settings, possibly as a consequence of a major input to soil organic matter from decomposition of dead tree-roots.

  19. Postoperative radiotherapy for parotid gland malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Keun Yong; Wu, Hong Gyun; Kim, Jae Sung; Park, Charn Il; Kim, Kwang Hyun; Lee, Chae Seo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Kim, In Ah [Bundang Seoul National University Hospital, Seongnam (Korea, Republic of)

    2005-09-15

    The aim of this study was to evaluate the clinical results of postoperative radiotherapy for parotid gland malignancy, and determine prognostic factors for locoregional control and survival. Between 1980 and 2002, 130 patients with parotid malignancy were registered in the database of the Department of Radiation Oncology, Seoul National University Hospital. The subjects of this analysis were the 72 of these 130 patients who underwent postoperative irradiation. There were 42 males and 30 females, with a median age of 46.5 years. The most common histological type was a mucoepidermoid carcinoma. There were 6, 23, 23 and 20 patients in Stages I, II, III and IV, respectively. The median dose to the tumor bed was 60 Gy, with a median fraction size of 1.8 Gy. The overall 5 and 10 year survival rates were 85 and 76%, respectively. The five-year locoregional control rate was 85%, which reached a plateau phase after 6 years. Sex and histological type were found to be statistically significant for overall survival from a multivariate analysis. No other factors, including age, facial nerve palsy and stage, were related to overall survival. For locoregional control, nodal involvement and positive resection margin were associated with poor local control. Histological type, tumor size, perineural invasion and type of surgery were not significant for locoregional control. A high survival rate of parotid gland malignancies, with surgery and postoperative radiotherapy, was confirmed. Sex and histological type were significant prognostic factors for overall survival. Nodal involvement and a positive resection margin were associated with poor locoregional control.

  20. Comparison of radioimmunotherapy and external beam radiotherapy in colon cancer xenografts

    International Nuclear Information System (INIS)

    Buras, R.R.; Wong, J.F.C.; Kuhn, J.A.; Beatty, B.G.; Williams, L.E.; Beatty, J.D.; Wanek, P.M.

    1993-01-01

    Radioimmunotherapy and external beam radiotherapy were compared in a nude mouse human colon cancer model. Radioimmunotherapy was delivered by intraperitoneal injection of 90 Y-labeled anticarcinoembryonic antigen monoclonal antibody (anti-CEA MAB). Single fraction external beam radiotherapy was delivered using a 60 Co teletherapy unit. Control groups received saline, unlabeled anit-CEA monoclonal antibody and labeled nonspecific monoclonal antibody. Tumor growth suppression was expressed as delay to reach 2g compared to saline controls. Unlabeled anti-CEA monoclonal antibody and labeled nonspecific monoclonal antibody had no effect. External beam radiotherapy of 300, 600, 1000 and 2000 cGy produced growth delays of 3, 12, 17, and 22 days, respectively. Radioimmunotherapy with 120 μCi, 175 μCi, and 225 μCi resulted in growth delays of 20, 34, and 36 days. Estimated absorbed tumor dose was 1750 cGy in the 120 μCi group. Similar comparisons were done with the more radioresistant WiDr human colon carcinoma cell line. External beam radiotherapy doses of 400, 800, 1200, and 1600 cGy resulted in growth delays of 6, 21, 36 and 48 days, respectively. Radioimmunotherapy of 120 μCi and 175 μCi resulted in growth delays of 9 and 19 days, respectively. The 120 μCi dose delivered an estimated absorbed tumor dose of 1080 cGy to WiDr tumors. In summary, for the radiosensitive LS174T line, radioimmunotherapy produced biologic effects that were comparable to a similar dose of single fraction external beam radiotherapy. For the more radioresistant WiDr tumor, radioimmunotherapy produced a biologic effect which was less than a similar dose of single fraction external beam radiotherapy. These studies suggest that a tumor's response to radioimmunotherapy relative to that of external beam radiotherapy is, in part, dependent on tumor radiosensitivity and repair capacity. 23 refs., 5 figs. 4 tabs

  1. Distribution, diversity and abundance of bacterial laccase-like genes in different particle size fractions of sediments in a subtropical mangrove ecosystem.

    Science.gov (United States)

    Luo, Ling; Zhou, Zhi-Chao; Gu, Ji-Dong

    2015-10-01

    This study investigated the diversity and abundance of bacterial lacasse-like genes in different particle size fractions, namely sand, silt, and clay of sediments in a subtropical mangrove ecosystem. Moreover, the effects of nutrient conditions on bacterial laccase-like communities as well as the correlation between nutrients and, both the abundance and diversity indices of laccase-like bacteria in particle size fractions were also studied. Compared to bulk sediments, Bacteroidetes, Caldithrix, Cyanobacteria and Chloroflexi were dominated in all 3 particle-size fractions of intertidal sediment (IZ), but Actinobacteria and Firmicutes were lost after the fractionation procedures used. The diversity index of IZ fractions decreased in the order of bulk > clay > silt > sand. In fractions of mangrove forest sediment (MG), Verrucomicrobia was found in silt, and both Actinobacteria and Bacteroidetes appeared in clay, but no new species were found in sand. The declining order of diversity index in MG fractions was clay > silt > sand > bulk. Furthermore, the abundance of lacasse-like bacteria varied with different particle-size fractions significantly (p clay > silt in both IZ and MG fractions. Additionally, nutrient availability was found to significantly affect the diversity and community structure of laccase-like bacteria (p fractions (p < 0.05). Therefore, this study further provides evidence that bacterial laccase plays a vital role in turnover of sediment organic matter and cycling of nutrients.

  2. Results of different modes conformal radiotherapy in treatment of cervical cancer

    International Nuclear Information System (INIS)

    Baranovs'ka, L.M.; Yivankova, V.S.; Khrulenko, T.V.; Skomorokhova, T.V.; Gorelyina, G.L.

    2017-01-01

    Development of techniques for cytotoxic treatment applying different modes of conformal radiotherapy, brachytherapy and high-energy (high dose rate - HDR) is one of the promising areas of optimization and efficiency of conservative treatment of patients with regional forms of cervical cancer. At Radiation Oncology Department, National Cancer Institute, 89 patients with stage 2b-3b cervical cancer, aged 29 to 70, underwent examination and combined radiotherapy course. The patients were divided into 2 main groups (56 patients) depending on the mode of developed conformal radiation therapy, and a control group made up by 33 patients (classic, default conformal radiotherapy). Results. Along with external beam radiotherapy, the patients of Group 2 were provided with conformal radiotherapy carried out by means of the linear accelerator of electrons in the mode of enhanced multi fractionation of irradiation dose applied to the small pelvis area (tumor and lymph efflux channels) with the single tumor dose 1.3 Gy twice per day once 4-6 hours up to the total radiation dose of 45 Gy applied to the small pelvis lymph nodes. The patients of Group 1 and the ones of the control group underwent conformal radiotherapy in the mode of standard fractionation applied to the small pelvis area with the single tumor dose of 1.8 Gy up to the total radiation dose of 45 Gy. Conformal radiotherapy was carried out for the patients of Group 1 associated with chemoradiomodifiers (tegafur, cisplatin). At the stage 2 of combined radiotherapy course, all patients underwent HDR brachytherapy via Co60 source in the mode of the single tumor dose of 5 Gy at point A up to the total radiation dose of 35-40 Gy. Therefore, employing accelerated mode of multifractiation in conformal radiotherapy of patients with regional cervical cancer makes it possible to enhance canrcinocidal irradiation doses applied to a tumor, and an interval between radiotherapy fractions provides conditions for initiation of

  3. ANALYSIS OF RESPIRATORY DESPOSITION DOSE OF INHALED AMBIENT AEROSOLS FOR DIFFERENT SIZE FRACTIONS

    Science.gov (United States)

    ANALYSIS OF RESPIRATORY DEPOSITION DOSE OF INHALED AMBIENT AEROSOLS FOR DIFFERENT SIZE FRACTIONS. Chong S. Kim, SC. Hu**, PA Jaques*, US EPA, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711; **IIT Research Institute, Chicago, IL; *S...

  4. Carbon-ion radiotherapy for marginal lymph node recurrences of cervical cancer after definitive radiotherapy: a case report

    International Nuclear Information System (INIS)

    Tamaki, Tomoaki; Nakano, Takashi; Ohno, Tatsuya; Kiyohara, Hiroki; Noda, Shin-ei; Ohkubo, Yu; Ando, Ken; Wakatsuki, Masaru; Kato, Shingo; Kamada, Tadashi

    2013-01-01

    Recurrences of cervical cancer after definitive radiotherapy often occur at common iliac or para-aortic lymph nodes as marginal lymph node recurrences. Patients with these recurrences have a chance of long-term survival by optimal re-treatment with radiotherapy. However, the re-irradiation often overlaps the initial and the secondary radiotherapy fields and can result in increased normal tissue toxicities in the bowels or the stomach. Carbon-ion radiotherapy, a form of particle beam radiotherapy using accelerated carbon ions, offers more conformal and sharp dose distribution than X-ray radiotherapy. Therefore, this approach enables the delivery of high radiation doses to the target while sparing its surrounding normal tissues. Marginal lymph node recurrences in common iliac lymph nodes after radiotherapy were treated successfully by carbon-ion radiotherapy in two patients. These two patients were initially treated with a combination of external beam radiotherapy and intracavitary and interstitial brachytherapy. However, the diseases recurred in the lymph nodes near the border of the initial radiotherapy fields after 22 months and 23 months. Because re-irradiation with X-ray radiotherapy may deliver high doses to a section of the bowels, carbon-ion radiotherapy was selected to treat the lymph node recurrences. A total dose of 48 Gy (RBE) in 12 fractions over 3 weeks was given to the lymph node recurrences, and the tumors disappeared completely with no severe acute toxicities. The two patients showed no evidence of disease for 75 months and 63 months after the initial radiotherapy and for 50 months and 37 months after the carbon-ion radiotherapy, respectively. No severe late adverse effects are observed in these patients. The two presented cases suggest that the highly conformal dose distribution of carbon-ion radiotherapy may be beneficial in the treatment of marginal lymph node recurrences after radiotherapy. In addition, the higher biological effect of carbon

  5. The result of radiotherapy for pituitary adenoma

    International Nuclear Information System (INIS)

    Lee, H. J.; Yang, K. M.; Suh, S. H.

    1997-01-01

    To evaluate the prognostic factors for disease-free survival and long-term results of radiotherapy for pituitary adenoma. The study involved a retrospective review of outcome in a series of 27 patients with pituitary adenoma, between 1984 and 1995 at Paik hospital. The study included 20 patients treated with surgery and postoperative radiotherapy and 7 with radiotherapy alone. The patients were followed for 12-146 months (median: 97 months). Seventeen were men and 10 were women. The numbers of functioning and non-functioning pituitary adenoma were 22 and 5 respectively and those of microadenoma and macroadenoma were 4 and 23 respectively. The radiation doses of 5040-5580cGy(median: 5040cGy) were delivered over 5-7 weeks, using 4MV LINAC. The prognostic factors were analyzed by log-rank test. For radiation therapy alone, the 5 YSR was 100% and progression free survival rate was 85.8%. The tumor was controlled in 6/7 (85.8%). For surgery and postoperative radiotherapy , the 5YSR, progression free survival rate and local control rate were 95%, 84.8%, and 89.5% respectively. The parameters of tumor size, hormone secretion, radiation dose, radiotherapy field size were evaluated in a uni- and multivariate analysis and all the factors were not statistically significant (P>0.05). Eleven of 12 (92%) with visual field defect experienced normalization or improvement, and 5 for 7 evaluable patients with hyperprolactinoma achieved normalization in 4 and decrement in 5 patients. Only 2 patients developed mild degree of panhypopituitarism. The radiotherapy appears to be effective in controlling clinical symptoms and signs resulting from pituitary adenoma. Local control rate with radiotherapy alone or with surgery and postoperative radiotherapy was comparable. There was a trend toward high recurrence rate in patients with nonfunctioning or prolactin secreting tumor and larger radiation field sizes. (author)

  6. The result of radiotherapy for pituitary adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H. J.; Yang, K. M.; Suh, S. H. [Inje Univ., Seoul (Korea, Republic of). Coll. of Medicine; Cho, H. L.; Shon, S. C. [Pusan Paik Hospital, Pusan (Korea, Republic of)

    1997-12-01

    To evaluate the prognostic factors for disease-free survival and long-term results of radiotherapy for pituitary adenoma. The study involved a retrospective review of outcome in a series of 27 patients with pituitary adenoma, between 1984 and 1995 at Paik hospital. The study included 20 patients treated with surgery and postoperative radiotherapy and 7 with radiotherapy alone. The patients were followed for 12-146 months (median: 97 months). Seventeen were men and 10 were women. The numbers of functioning and non-functioning pituitary adenoma were 22 and 5 respectively and those of microadenoma and macroadenoma were 4 and 23 respectively. The radiation doses of 5040-5580cGy(median: 5040cGy) were delivered over 5-7 weeks, using 4MV LINAC. The prognostic factors were analyzed by log-rank test. For radiation therapy alone, the 5 YSR was 100% and progression free survival rate was 85.8%. The tumor was controlled in 6/7 (85.8%). For surgery and postoperative radiotherapy , the 5YSR, progression free survival rate and local control rate were 95%, 84.8%, and 89.5% respectively. The parameters of tumor size, hormone secretion, radiation dose, radiotherapy field size were evaluated in a uni- and multivariate analysis and all the factors were not statistically significant (P>0.05). Eleven of 12 (92%) with visual field defect experienced normalization or improvement, and 5 for 7 evaluable patients with hyperprolactinoma achieved normalization in 4 and decrement in 5 patients. Only 2 patients developed mild degree of panhypopituitarism. The radiotherapy appears to be effective in controlling clinical symptoms and signs resulting from pituitary adenoma. Local control rate with radiotherapy alone or with surgery and postoperative radiotherapy was comparable. There was a trend toward high recurrence rate in patients with nonfunctioning or prolactin secreting tumor and larger radiation field sizes. (author).

  7. Concurrent Boost with Adjuvant Breast Hypofractionated Radiotherapy and Toxicity Assessment

    Directory of Open Access Journals (Sweden)

    Mona M. Sayed

    2015-01-01

    Full Text Available Background: The use of shorter radiotherapy schedules has an economic and logistic advantage for radiotherapy departments, as well as a high degree of patient convenience. The aim of this study is to assess the acute and short-term late toxicities of a hypofractionated radiotherapy schedule with a concomitant boost. Methods: We enrolled 57 eligible patients as group A. These patients received 42.5 Gy in 16 fractions of 2.66 Gy each to the whole breast over 3.2 weeks. A concomitant electron boost of 12 Gy in 16 fractions was also administered which gave an additional 0.75 Gy daily to the lumpectomy area for a total radiation dose of 54.5 Gy. Toxicity was recorded at three weeks and at three months for this group as well as for a control group (group B. The control group comprised 76 eligible patients treated conventionally with 50 Gy to the whole breast over five weeks followed by a sequential electron boost of 12 Gy in 2 Gy per fraction. Results: There were no statistically significant differences observed in the incidence of acute skin toxicity, breast pain, and edema recorded at three weeks or pigmentation and fibrosis recorded at three months between the two groups (P0.05. Conclusion: The results of this study suggest there are no increased acute and shortterm late toxicities affiliated with the hypofractionated schedule plus a concomitant boost as prescribed compared to the conventional fractionation of adjuvant breast radiotherapy. Large randomized trials and long-term follow-up are needed to confirm these favorable findings.

  8. Does fast-neutron radiotherapy merely reduce the radiation dose

    International Nuclear Information System (INIS)

    Ando, Koichi

    1984-01-01

    We examined whether fast-neutron radiotherapy is superior to low-LET radiotherpy by comparing the relationship between cell survival and tumor control probabilities after exposure of tumor-bearing (species) to the two modalities. Analysis based on TCD 50 assay and lung colony assay indicated that single dose of fast neutron achieved animal cures at higher survival rates than other radiation modalities including single and fractionated γ-ray doses, fractionated doses of fast neutron, and the mixed-beam scheme with a sequence of N-γ-γ-γ-N. We conclude that fast-neutron radiotherapy cured animal tumors with lower cell killing rates other radiation modalities. (author)

  9. Dental status, dental rehabilitation procedures, demographic and oncological data as potential risk factors for infected osteoradionecrosis of the lower jaw after radiotherapy for oral neoplasms: a retrospective evaluation

    International Nuclear Information System (INIS)

    Niewald, Marcus; Fleckenstein, Jochen; Mang, Kristina; Holtmann, Henrik; Spitzer, Wolfgang J; Rübe, Christian

    2013-01-01

    Retrospective evaluation of the dental status of patients with oral cancer before radiotherapy, the extent of dental rehabilitation procedures, demographic and radiotherapy data as potential risk factors for development of infected osteoradionecrosis of the lower jaw. A total of 90 patients who had undergone radiotherapy for oral cancer were included into this retrospective evaluation. None of them had distant metastases. After tumour surgery the patients were referred to an oral and maxillofacial surgeon for dental examination and the necessary dental rehabilitation procedures inclusive potential tooth extraction combined with primary soft tissue closure. Adjuvant radiotherapy was started after complete healing of the gingiva (> 7 days after potential extraction). The majority of patients (n = 74) was treated with conventionally fractionated radiotherapy with total doses ranging from 50-70Gy whereas further 16 patients received hyperfractionated radiotherapy up to 72Gy. The records of the clinical data were reviewed. Furthermore, questionnaires were mailed to the patients’ general practitioners and dentists in order to get more data concerning tumour status and osteoradionecrosis during follow-up. The patients’ dental status before radiotherapy was generally poor. On average 10 teeth were present, six of them were regarded to remain conservable. Extensive dental rehabilitation procedures included a mean of 3.7 tooth extractions. Chronic periodontitis with severe attachment loss was found in 40%, dental biofilm in 56%. An infected osteoradionecrosis (IORN) grade II according to (Schwartz et al., Am J Clin Oncol 25:168-171, 2002) was diagnosed in 11 of the 90 patients (12%), mostly within the first 4 years after radiotherapy. We could not find significant prognostic factors for the occurrence of IORN, but a trendwise correlation with impaired dental status, rehabilitation procedures, fraction size and tumour outcome. The occurrence of IORN is an important long

  10. Dental status, dental rehabilitation procedures, demographic and oncological data as potential risk factors for infected osteoradionecrosis of the lower jaw after radiotherapy for oral neoplasms: a retrospective evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Niewald, Marcus; Fleckenstein, Jochen [Department of Radiotherapy and Radiooncology, Saarland University Medical Center, Kirrberger Str. 1, D-66421 Homburg (Germany); Mang, Kristina [Dental Practice, Duisburg (Germany); Holtmann, Henrik; Spitzer, Wolfgang J [Department of Oral and Maxillofacial Surgery, Saarland University Medical Center, Kirrberger Str. 1, D-66421 Homburg (Germany); Rübe, Christian [Department of Radiotherapy and Radiooncology, Saarland University Medical Center, Kirrberger Str. 1, D-66421 Homburg (Germany)

    2013-10-02

    Retrospective evaluation of the dental status of patients with oral cancer before radiotherapy, the extent of dental rehabilitation procedures, demographic and radiotherapy data as potential risk factors for development of infected osteoradionecrosis of the lower jaw. A total of 90 patients who had undergone radiotherapy for oral cancer were included into this retrospective evaluation. None of them had distant metastases. After tumour surgery the patients were referred to an oral and maxillofacial surgeon for dental examination and the necessary dental rehabilitation procedures inclusive potential tooth extraction combined with primary soft tissue closure. Adjuvant radiotherapy was started after complete healing of the gingiva (> 7 days after potential extraction). The majority of patients (n = 74) was treated with conventionally fractionated radiotherapy with total doses ranging from 50-70Gy whereas further 16 patients received hyperfractionated radiotherapy up to 72Gy. The records of the clinical data were reviewed. Furthermore, questionnaires were mailed to the patients’ general practitioners and dentists in order to get more data concerning tumour status and osteoradionecrosis during follow-up. The patients’ dental status before radiotherapy was generally poor. On average 10 teeth were present, six of them were regarded to remain conservable. Extensive dental rehabilitation procedures included a mean of 3.7 tooth extractions. Chronic periodontitis with severe attachment loss was found in 40%, dental biofilm in 56%. An infected osteoradionecrosis (IORN) grade II according to (Schwartz et al., Am J Clin Oncol 25:168-171, 2002) was diagnosed in 11 of the 90 patients (12%), mostly within the first 4 years after radiotherapy. We could not find significant prognostic factors for the occurrence of IORN, but a trendwise correlation with impaired dental status, rehabilitation procedures, fraction size and tumour outcome. The occurrence of IORN is an important long

  11. Carbon Storage in Soil Size Fractions Under Two Cacao Agroforestry Systems in Bahia, Brazil

    Science.gov (United States)

    Gama-Rodrigues, Emanuela F.; Ramachandran Nair, P. K.; Nair, Vimala D.; Gama-Rodrigues, Antonio C.; Baligar, Virupax C.; Machado, Regina C. R.

    2010-02-01

    Shaded perennial agroforestry systems contain relatively high quantities of soil carbon (C) resulting from continuous deposition of plant residues; however, the extent to which the C is sequestered in soil will depend on the extent of physical protection of soil organic C (SOC). The main objective of this study was to characterize SOC storage in relation to soil fraction-size classes in cacao ( Theobroma cacao L.) agroforestry systems (AFSs). Two shaded cacao systems and an adjacent natural forest in reddish-yellow Oxisols in Bahia, Brazil were selected. Soil samples were collected from four depth classes to 1 m depth and separated by wet-sieving into three fraction-size classes (>250 μm, 250-53 μm, and cacao AFSs, the C contained in the macroaggregate fraction might become stabilized in the soil. The study shows the role of cacao AFSs in mitigating greenhouse gas (GHG) emission through accumulation and retention of high amounts of organic C in the soils and suggests the potential benefit of this environmental service to the nearly 6 million cacao farmers worldwide.

  12. Effects of low dose mitomycin C on experimental tumor radiotherapy

    International Nuclear Information System (INIS)

    Yang Jianzheng; Liang Shuo; Qu Yaqin; Pu Chunji; Zhang Haiying; Wu Zhenfeng; Wang Xianli

    2001-01-01

    Objective: To evaluate the possibility of low dose mitomycin C(MMC) as an adjunct therapy for radiotherapy. Methods: Change in tumor size tumor-bearing mice was measured. Radioimmunoassay was used to determine immune function of mice. Results: Low dose Mac's pretreatment reduced tumor size more markedly than did radiotherapy only. The immune function in mice given with low dose MMC 12h before radiotherapy was obviously higher than that in mice subjected to radiotherapy only (P<0.05), and was close to that in the tumor-bearing mice before radiotherapy. Conclusion: Low dose MMC could improve the radiotherapy effect. Pretreatment with low dose MMC could obviously improve the immune suppression state in mice caused by radiotherapy. The mechanism of its improvement of radiotherapeutic effect by low dose of MMC might be due to its enhancement of immune function and induction of adaptive response in tumor-bearing mice

  13. The pentane- and toluene-soluble fractions of a petroleum residue and three coal tars by size exclusion chromatography and UV-fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Karaca, F.; Millan-Agorio, M.; Morgan, T.J.; Bull, I.D.; Herod, A.A.; Kandiyoti, R. [University of London Imperial College Science Technology & Medicine, London (United Kingdom). Dept. of Chemical Engineering

    2008-01-15

    A petroleum atmospheric pressure distillate residue and three tars derived from different coals using different severities of thermal treatment were separated into seven fractions using column chromatography on silica and sequential elution by the solvent sequence pentane, toluene, acetonitrile, pyridine, 1-methyl-2-pyrrolidinone (NMP) and water. The fractions from the four extractions have been compared using size exclusion chromatography (SEC) in NMP as eluent and by synchronous ultra-violet-fluorescence (UV-F). This paper concerns the pentane and toluene soluble fractions only since these are the least polar fractions. By SEC, the size of the aromatic molecules increased from the first pentane soluble fractions to the toluene-soluble fractions, with the petroleum residue fractions of larger size than the equivalent fractions from coal liquids. The three coal tars showed significant differences, indicating that temperature of pyrolysis had a significant effect on the molecular size. Synchronous UV-F spectra of the four sets of fractions, in solution in NMP, again showed significant differences between the petroleum residue and the coal tars, as well as amongst the three coal tars. In general, the petroleum residue fractions contained smaller aromatic clusters than the coal liquid fractions. These low-polarity fractions contained material excluded from the column porosity in SEC that was unlikely to consist of aggregates of polar molecules.

  14. Radiotherapy of macular lesions in age-related macular degeneration (A.M.D.): preliminary results of a clinical study conducted in Lyon, France

    International Nuclear Information System (INIS)

    Martin, P.; Mauget, M.; Gerard, J.P.

    1997-01-01

    To evaluate irradiation effects on functional signs and choroidal neo-vascular lesions in age-related macular degeneration (AMD) that does not respond to laser therapy. Since 1994, 250 consecutive AMD patients were treated by two radiotherapy teams for sub-foveal neo-vascular lesions. At the end of september 1996, 52 patients were evaluable with a 1-year follow-up. Group 1 (Department de Radiotherapie Oncologie, Centre Hospitalo-Universitaire Lyon Sud) included 26 patients who were treated with a lateral beam of 6 MV photons. The irradiation dose were 20 Gy in five fractions for small lesions and 28.8 Gy in eight fractions for larger lesions. Group 2 (Centre Oncologie Radiotherapie Saint-Jean) was composed of 26 patients treated with a mini-beam of 25 MV photons via lateral arc-therapy. Beam diameters (14 and 18 mm) were adapted to the lesion size. The total dose was 16 Gy in four fractions or 20 Gy in five fractions. Functional and anatomical results were assessed at 3, 6, 9 months and 1 year after radiation therapy. Stable visual acuity was observed in 44 % (23/52) of the patients and visual acuity was improved in 35 % (18/52) of the patients at 6 months. Good functional results reached 79 % (41/52) at 6 months and 74 % (17/23) at 12 months. There was no statistical difference between the two groups and dose levels. All severe complications (1 cataract, 3 dilated choroidal vessels, and 2 papillitis) occurred in group 1. Though it is too early to conclude on the best dose level, radiotherapy of sub-foveal neo-vascular lesions of AMD that cannot be treated via laser therapy provides encouraging results. The technique used must be very precise to adequately irradiate the fovea and spare surrounding sensitive areas. Further studies and trials involving patients' randomization are necessary to confirm these preliminary results. (author)

  15. The role of soil's particle-size fractions in the adsorption of heavy metals

    Directory of Open Access Journals (Sweden)

    Saglara Mandzhieva

    2014-08-01

    Full Text Available The parameters of adsorption of Cu2+, Pb2+, and Zn2+ cations by southern chernozem and their particle-size fractions were studied. The adsorption of metals by soils and the strength of their fixation on the surface of soil particles under both mono- and poly-element contamination decreased with the decreasing proportion of fine fractions in the soil. The aim of this work was to study the effect of the particle-size distribution and the silt and physical clay fractions on the adsorption of copper, lead, and zinc by chernozems. The objects of study included the upper humus horizons of different southern chernozems of the Rostov oblast. To study the ion-exchange adsorption of the Cu2+, Pb2+, and Zn2+ cations, the soil in the natural ionic form was disaggregated using a pestle with a rubber head and sieved through a 1mm sieve. The soil samples were treated with solutions of Cu2+, Pb2+, and Zn2+ nitrates and acetates at the separate and simultaneous presence of heavy metals (HMs. In the solutions with the simultaneous presence of HMs, their molar concentrations were similar. The concentrations of the initial solutions varied in the range from 0.05 to 1 mM/l. The soil: solution ratio was 1:10. The contents of HMs in the filtrates were determined by atomic absorption spectrophotometry. The contents of adsorbed HM cations were calculated from the difference between the metal concentrations in the initial and equilibrium solutions. The increase in the degree of dispersion of the particle-size fractions in similar soils resulted not only in an increase in the content of adsorbed HMs but also in an enhancement of their fixation on the surface of the fine particles. Therefore, the adsorption capacity of the Lower Don soils for Cu2+, Pb2+, and Zn2+ decreased in the following sequence: clay loamy southern chernozem > loamy southern chernozem > loamy sandy southern chernozem. This was related to the qualitative differences in the mineralogy and chemistry of

  16. The Confluence of Stereotactic Ablative Radiotherapy and Tumor Immunology

    Directory of Open Access Journals (Sweden)

    Steven Eric Finkelstein

    2011-01-01

    Full Text Available Stereotactic radiation approaches are gaining more popularity for the treatment of intracranial as well as extracranial tumors in organs such as the liver and lung. Technology, rather than biology, is driving the rapid adoption of stereotactic body radiation therapy (SBRT, also known as stereotactic ablative radiotherapy (SABR, in the clinic due to advances in precise positioning and targeting. Dramatic improvements in tumor control have been demonstrated; however, our knowledge of normal tissue biology response mechanisms to large fraction sizes is lacking. Herein, we will discuss how SABR can induce cellular expression of MHC I, adhesion molecules, costimulatory molecules, heat shock proteins, inflammatory mediators, immunomodulatory cytokines, and death receptors to enhance antitumor immune responses.

  17. Four-week arc radiotherapy for B2-C prostate cancer: The need for prospective evaluation of short fractionation schemes

    International Nuclear Information System (INIS)

    Graham, P.H.; Morris, W. J.; Pickles, T.P.; Graham, P.H.

    1997-01-01

    A retrospective review of 173 men with clinical stage B2-C prostate cancer treated by small-volume arc radiotherapy to 5200 cGy in 16 fractions over 4 weeks was undertaken. At 5 years, clinical local failure rates were 14% for stage B2 and 18% for stage C. Five-year survival rates were 81 and 61%, respectively. No discernible differences were detected between a policy of encompassing the planning target volume by the 90% or 95% isodose. The limitations of this retrospective evidence and that of the literature are discussed. In the context of resource limitations affecting radiation oncology, prospective assessment of this technique is required to determine the true outcome. (authors)

  18. Oxygenation of cervical cancers during radiotherapy and radiotherapy + cis-retinoic acid/interferon

    International Nuclear Information System (INIS)

    Dunst, Jeurgen; Heansgen, Gabriele; Lautenschleager, Christine; Feuchsel, Glenn; Becker, Axel

    1999-01-01

    Purpose: We have evaluated the tumor tissue pO 2 in cervical cancers during radiotherapy with special emphasis on the course of the pO 2 in primarily hypoxic tumors and in patients treated with radiotherapy plus 13-cis-retinoic acid/interferon-α-2a. Methods and Materials: From June 1995 through April 1997, 49 patients with squamous cell carcinoma FIGO IIB-IVA of the cervix who were treated with definitve radiotherapy with curative intent underwent polarographic measurement of tumor tissue pO 2 with an Eppendorf pO 2 -histograph prior to and during radiation treatment. Radiotherapy consisted of external irradiation with 50.4 Gy in 28 fractions of 1.8 Gy plus high dose rate (HDR) brachytherapy. Twenty-two patients had additional treatment with 13-cis-retinoic acid (cRA, isotretinoin) and interferon-α-2a (IFN-α-2a). Therapy with cRA/IFN in these patients started 2 weeks before radiotherapy; during this induction period, cRA was administered in a dosage of 1 mg per kilogram body weight orally daily and IFN-α-2a in a dosage of 6 x 10 6 I.U. subcutaneously daily. After start of external radiotherapy (XRT), cRA/IFN was continued concomitantly with radiotherapy in reduced doses (0.5 mg cRA per kg body weight orally daily plus 3 x 10 6 I.U. IFN-α-2a subcutaneously three times weekly until the end of the radiation treatment). pO 2 measurements were performed prior to radiotherapy, at 20 Gy, and at the end of radiotherapy. Results: A poor oxygenation defined as a median pO 2 of 10 mm Hg or less was present in 15/38 tumors (39%) in which measurements prior to any treatment were done. Low pO 2 readings below 5 mm Hg were present in 70% of all tumors prior to treatment. In 13 of 15 hypoxic tumors, pO 2 measurements at 19.8 Gy were performed. In these tumors, a significant increase of the median pO 2 from 6.0 ± 3.1 mm Hg to 20.7 ± 21.2 mm Hg was found, p 2 was more pronounced in patients with radiotherapy plus additional cRA/IFN treatment as compared to patients treated

  19. Adjuvant or radical fractionated stereotactic radiotherapy for patients with pituitary functional and nonfunctional macroadenoma

    Directory of Open Access Journals (Sweden)

    Weber Damien C

    2011-12-01

    Full Text Available Abstract Purpose To evaluate the efficacy and toxicity of stereotactic fractionated radiotherapy (SFRT for patients with pituitary macroadenoma (PMA. Methods and Materials Between March 2000 and March 2009, 27 patients (male to female ratio, 1.25 with PMA underwent SFRT (median dose, 50.4 Gy. Mean age of the patients was 56.5 years (range, 20.3 - 77.4. In all but one patient, SFRT was administered for salvage treatment after surgical resection (transphenoidal resection in 23, transphenoidal resection followed by craniotomy in 2 and multiple transphenoidal resections in another patient. In 10 (37% patients, the PMAs were functional (3 ACTH-secreting, 3 prolactinomas, 2 growth hormone-secreting and 2 multiple hormone-secretion. Three (11.1% and 9 (33.3% patients had PMA abutting and compressing the optic chiasm, respectively. Mean tumor volume was 2.9 ± 4.6 cm3. Eighteen (66.7% patients had hypopituitarism prior to SFRT. The mean follow-up period after SFRT was 72.4 ± 37.2 months. Results Tumor size decreased for 6 (22.2% patients and remained unchanged for 19 (70.4% other patients. Two (7.4% patients had tumor growth inside the prescribed treatment volume. The estimated 5-year tumor growth control was 95.5% after SFRT. Biochemical remission occurred in 3 (30% patients with functional PMA. Two patients with normal anterior pituitary function before SFRT developed new deficits 25 and 65 months after treatment. The 5-year survival without new anterior pituitary deficit was thus 95.8%. Five patients with visual field defect had improved visual function and 1 patient with no visual defect prior to SFRT, but an optic chiasm abutting tumor, had a decline in visual function. The estimated 5-year vision and pituitary function preservation rates were 93.2% and 95.8%, respectively. Conclusions SFRT is a safe and effective treatment for patients with PMA, although longer follow-up is needed to evaluate long-term outcomes. In this study, approximately 1

  20. Adjuvant or radical fractionated stereotactic radiotherapy for patients with pituitary functional and nonfunctional macroadenoma

    International Nuclear Information System (INIS)

    Weber, Damien C; Momjian, Shahan; Pralong, François P; Meyer, Patrick; Villemure, Jean Guy; Pica, Alessia

    2011-01-01

    To evaluate the efficacy and toxicity of stereotactic fractionated radiotherapy (SFRT) for patients with pituitary macroadenoma (PMA). Between March 2000 and March 2009, 27 patients (male to female ratio, 1.25) with PMA underwent SFRT (median dose, 50.4 Gy). Mean age of the patients was 56.5 years (range, 20.3 - 77.4). In all but one patient, SFRT was administered for salvage treatment after surgical resection (transphenoidal resection in 23, transphenoidal resection followed by craniotomy in 2 and multiple transphenoidal resections in another patient). In 10 (37%) patients, the PMAs were functional (3 ACTH-secreting, 3 prolactinomas, 2 growth hormone-secreting and 2 multiple hormone-secretion). Three (11.1%) and 9 (33.3%) patients had PMA abutting and compressing the optic chiasm, respectively. Mean tumor volume was 2.9 ± 4.6 cm 3 . Eighteen (66.7%) patients had hypopituitarism prior to SFRT. The mean follow-up period after SFRT was 72.4 ± 37.2 months. Tumor size decreased for 6 (22.2%) patients and remained unchanged for 19 (70.4%) other patients. Two (7.4%) patients had tumor growth inside the prescribed treatment volume. The estimated 5-year tumor growth control was 95.5% after SFRT. Biochemical remission occurred in 3 (30%) patients with functional PMA. Two patients with normal anterior pituitary function before SFRT developed new deficits 25 and 65 months after treatment. The 5-year survival without new anterior pituitary deficit was thus 95.8%. Five patients with visual field defect had improved visual function and 1 patient with no visual defect prior to SFRT, but an optic chiasm abutting tumor, had a decline in visual function. The estimated 5-year vision and pituitary function preservation rates were 93.2% and 95.8%, respectively. SFRT is a safe and effective treatment for patients with PMA, although longer follow-up is needed to evaluate long-term outcomes. In this study, approximately 1 patient with visual field defect out of two had an improved

  1. Assessment of factors connected with radiotherapy influencing the cosmetic effect in breast conserving therapy

    International Nuclear Information System (INIS)

    Blaszczyk, P.; Roszkowski, K.; Blaszczyk, E.; Kowalewski, J.

    2009-01-01

    Aim: To compare cosmetic results of different radiotherapy schedules used in the treatment of breast cancer after breast radiotherapy and to identify factors affecting cosmetic outcomes. Material and methods: Ninety-four patients irradiated. Median follow-up of 29 months (range 18-154 mo.). Patients were treated with standard fractionation 45-50 Gy/20-25 fx/4-5 weeks. Boost up to 10 Gy. Late effects were evaluated using the LENT-SOMA scoring scale. The cosmetic results were assessed on a four-point scale and presence of concomitant chemotherapy. Results: LENT-SOMA grade 3 toxicity was observed only in 8 (8,5%) patients. The factor associated with hyperpigmentation is large breast size. The significant risk factors for teleangiectasia are high dose and use photon energy 1,33 MeV beam. Factors found to impact significantly cosmetics adversely fibrosis was large breast size. Breast fibrosis were more frequent observed in woman after whole dose 50 Gy. There were no differences in breast skin thick between analysed factors. Conclusions: After irradiating large breasts more often than one observes the fibrosis of the breast in the case of small and average breasts and discolour of the skin. Irradiating photons from the cobalt source in the comparison with photons about higher energy at women with large breasts, there is the reason more frequent occurrence of the skin angioma. For the final cosmetic effect of radiotherapy in saving treatment, they do not have the impact: tumor size, boost method, chemical treatment, patients age. (authors)

  2. X-ray volume imaging in bladder radiotherapy verification

    International Nuclear Information System (INIS)

    Henry, Ann M.; Stratford, Julia; McCarthy, Claire; Davies, Julie; Sykes, Jonathan R.; Amer, Ali; Marchant, Tom; Cowan, Richard; Wylie, James; Logue, John; Livsey, Jacqueline; Khoo, Vincent S.; Moore, Chris; Price, Pat

    2006-01-01

    Purpose: To assess the clinical utility of X-ray volume imaging (XVI) for verification of bladder radiotherapy and to quantify geometric error in bladder radiotherapy delivery. Methods and Materials: Twenty subjects undergoing conformal bladder radiotherapy were recruited. X-ray volume images and electronic portal images (EPIs) were acquired for the first 5 fractions and then once weekly. X-ray volume images were co-registered with the planning computed tomography scan and clinical target volume coverage assessed in three dimensions (3D). Interfraction bladder volume change was described by quantifying changes in bladder volume with time. Bony setup errors were compared from both XVI and EPI. Results: The bladder boundary was clearly visible on coronal XVI views in nearly all images, allowing accurate 3D treatment verification. In 93.5% of imaged fractions, the clinical target volume was within the planning target volume. Most subjects displayed consistent bladder volumes, but 25% displayed changes that could be predicted from the first three XVIs. Bony setup errors were similar whether calculated from XVI or EPI. Conclusions: Coronal XVI can be used to verify 3D bladder radiotherapy delivery. Image-guided interventions to reduce geographic miss and normal tissue toxicity are feasible with this technology

  3. Defining patient-based minimal clinically important effect sizes: a study in palliative radiotherapy for painful unresectable pelvic recurrences from rectal cancer

    International Nuclear Information System (INIS)

    Wong, Rebecca K.S.; Gafni, Amiram; Whelan, Tim; Franssen, Edmee; Fung, Karen

    2002-01-01

    Purpose: To measure patient-based minimal clinically important effect sizes (minimal incremental benefit that an individual would require to accept one treatment option over another) for pain relief between two contrasting palliative radiotherapy regimens for painful pelvic recurrences from rectal cancer. Methods and Materials: Forty-three patients with a history of cancer pain without prior pelvic radiotherapy participated in decision aid-facilitated trade-off exercises. The clinical scenario and treatment options of a 5-day vs. a 20-day course of radiotherapy were described. The duration of pain relief for the 20-day regimen was increased until the respondents' preferences switched to the 20-day regimen. The exercises were repeated for different probabilities of benefit and pain intensity at the time of decision making. Results: When the probability of pain relief was unchanged, the median switch point for the duration of pain relief was 6.7 and 7.2 months for severe and mild pain, respectively. The cumulative percentage frequency curve for the switch points approximated a sigmoid distribution. Conclusion: Determining the minimal clinically important effect sizes for symptom relief for palliative therapies is feasible. This type of information can be used to incorporate patient values into clinical trial designs. Modification of this method can be used to improve our understanding of shared (physician and patient) decision making

  4. Effect of image-guided hypofractionated stereotactic radiotherapy on peripheral non-small-cell lung cancer

    Directory of Open Access Journals (Sweden)

    Wang SW

    2016-08-01

    Full Text Available Shu-wen Wang,1 Juan Ren,1 Yan-li Yan,2 Chao-fan Xue,2 Li Tan,2 Xiao-wei Ma2 1Department of Radiotherapy, First Affiliated Hospital of Xian Jiaotong University, 2Medical School of Xian Jiaotong University, Xi’an, Shaanxi, People’s Republic of China Abstract: The objective of this study was to compare the effects of image-guided hypofractionated radiotherapy and conventional fractionated radiotherapy on non-small-cell lung cancer (NSCLC. Fifty stage- and age-matched cases with NSCLC were randomly divided into two groups (A and B. There were 23 cases in group A and 27 cases in group B. Image-guided radiotherapy (IGRT and stereotactic radiotherapy were conjugately applied to the patients in group A. Group A patients underwent hypofractionated radiotherapy (6–8 Gy/time three times per week, with a total dose of 64–66 Gy; group B received conventional fractionated radiotherapy, with a total dose of 68–70 Gy five times per week. In group A, 1-year and 2-year local failure survival rate and 1-year local failure-free survival rate were significantly higher than in group B (P<0.05. The local failure rate (P<0.05 and distant metastasis rate (P>0.05 were lower in group A than in group B. The overall survival rate of group A was significantly higher than that of group B (P=0.03, and the survival rate at 1 year was 87% vs 63%, (P<0.05. The median survival time of group A was longer than that of group B. There was no significant difference in the incidence of complications between the two groups (P>0.05. Compared with conventional fractionated radiation therapy, image-guided hypofractionated stereotactic radiotherapy in NSCLC received better treatment efficacy and showed good tolerability. Keywords: non-small-cell lung cancer, hypofractionated radiotherapy, stereotactic radiotherapy, segmentation, intensity-modulated radiotherapy, image-guided radiation therapy technology

  5. Fractal aspects of the flow and shear behaviour of free-flowable particle size fractions of pharmaceutical directly compressible excipient sorbitol.

    Science.gov (United States)

    Hurychová, Hana; Lebedová, Václava; Šklubalová, Zdenka; Dzámová, Pavlína; Svěrák, Tomáš; Stoniš, Jan

    Flowability of powder excipients is directly influenced by their size and shape although the granulometric influence of the flow and shear behaviour of particulate matter is not studied frequently. In this work, the influence of particle size on the mass flow rate through the orifice of a conical hopper, and the cohesion and flow function was studied for four free-flowable size fractions of sorbitol for direct compression in the range of 0.080-0.400 mm. The particles were granulometricaly characterized using an optical microscopy; a boundary fractal dimension of 1.066 was estimated for regular sorbitol particles. In the particle size range studied, a non-linear relationship between the mean particle size and the mass flow rate Q10 (g/s) was detected having amaximum at the 0.245mm fraction. The best flow properties of this fraction were verified with aJenike shear tester due to the highest value of flow function and the lowest value of the cohesion. The results of this work show the importance of the right choice of the excipient particle size to achieve the best flow behaviour of particulate material.Key words: flowability size fraction sorbitol for direct compaction Jenike shear tester fractal dimension.

  6. A retrospective study of the effectiveness of hemostatic radiotherapy with conventional fractionation in patients with advanced cancer

    Directory of Open Access Journals (Sweden)

    Nomoto S

    2015-12-01

    Full Text Available The aim of this study was to assess the efficacy of hemostatic radiotherapy (HRT in patients with advanced cancer. Eighteen patients with advanced cancer treated with HRT at the Fukuoka University and Kyushu Rosai Hospitals in Japan between July 2010 and February 2015 were retrospectively assessed. The hemostatic effect of tumor-related bleeding was assessed by the clinical course of bleeding, laboratory data, the endoscopic study, and the number of blood transfusion units (BTRUs for one month before and after HRT. The median follow-up time was 2.6 months (range, 0.7 to 36.2 months. The median age of the patients was 77 years (range, 51 to 93. The primary diseases with tumor-related bleeding included gastric cancer, urinary bladder cancer, gynecological cancer, prostate cancer, non-small-cell lung cancer, and breast cancer. The median overall survival time was three months, and the one year survival rate was 22.9% of all patients. The HRT regimens ranged from 30 Gy in 10 fractions to 40 Gy in 20 fractions. In all patients, the anemia grade and the number of BTRUs decreased for 1 month after RT. The percentage of patients who were diagnosed as “successful” for hemostasis was 83% (15 of 18 patients. HRT is therefore strongly suggested as effective for the control of tumor-related bleeding in patients with advanced cancer. The optimal radiation doses and fractions are controversial; however, this treatment should be offered for patients with a poor life expectancy.

  7. Radiotherapy and brachytherapy

    International Nuclear Information System (INIS)

    2007-02-01

    This presentation first defines the radiotherapy and brachytherapy techniques, indicates the used ionizing radiations (electromagnetic and particles), describes the mechanisms and processes of action of ionizing radiations: they can be physical by photon-matter interactions (Compton effect and photoelectric effect) or due to electron-matter interactions (excitation, ionization), physical-chemical by direct or indirect action (DNA damage), cellular (mitotic or apoptotic death), tissue (sane and tumorous tissues and differential effect). It discusses the biological efficiency of these treatments which depends on different parameters: intrinsic radio-sensitivity, time (session fractioning and organisation in time), oxygen, radiation quality, cellular cycle, dose rate, temperature. It presents the different types of radiotherapy: external radiotherapy (general sequence, delineation, dosimetry, protection of critical organs, treatment session, quality control, monitoring consultation) and briefly presents some specific techniques (total body irradiation, total cutaneous electron therapy, pre-operation radiotherapy, radio-surgery, hadron-therapy). It proposes an overview of the main indications for this treatment: brain tumours, upper aero digestive tract tumours, bronchial tumours, oesophagus, stomach and pancreas tumours, breast tumours, cervix cancer, rectum tumour, and so on, and indicates the possible associated treatments. The next part addresses brachytherapy. It presents the principles and comments the differences with radiotherapy. It indicates the used radio-elements (Caesium 137, Iridium 192, Iodine 125), describes the implementation techniques (plastic tubes, use of iodine 125, intracavitary and endo-luminal radiation therapy). It proposes an overview of the different treated tumours (skin, breast, prostates, bronchial, oesophagus, ENT) and indicates possible early and late secondary effects for different organs

  8. Relation between PAH and black carbon contents in size fractions of Norwegian harbor sediments

    International Nuclear Information System (INIS)

    Oen, Amy M.P.; Cornelissen, Gerard; Breedveld, Gijs D.

    2006-01-01

    Distributions of total organic carbon (TOC), black carbon (BC), and polycyclic aromatic hydrocarbons (PAH) were investigated in different particle size fractions for four Norwegian harbor sediments. The total PAH (16-EPA) concentrations ranged from 2 to 113 mg/kg dry weight with the greatest fraction of PAH mass in the sand fraction for three of the four sediments. TOC contents ranged from 0.84% to 14.2% and BC contents from 0.085% to 1.7%. This corresponds to organic carbon (OC = TOC - BC) contents in the range of 0.81-14% and BC:TOC ratios of 1.3-18.1%. PAH isomer ratios suggested that the PAH in all four sediments were of pyrogenic origin. Furthermore, stronger correlations between PAH versus BC (r 2 = 0.85) than versus OC (r 2 = 0.15) were found. For all size fractions and bulk sediments, the PAH-to-BC ratios for the total PAHs were on average 6 ± 3 mg PAH/g BC. These results suggest that PAH distributions were dominated by the presence of BC, rather than OC. As sorption to BC is much stronger than sorption to OC, this may result in significantly lower dissolved concentrations of PAH than expected on the basis of organic carbon partitioning alone. - PAH contents correlated better with black carbon than organic carbon for four Norwegian harbor sediments

  9. Comparison of layer grain size analysis with pipette and sieve analysis: a solution for the underestimation of the clay fraction

    NARCIS (Netherlands)

    Konert, M.; Vandenberghe, J.F.

    1997-01-01

    Classically, the grain size of soil and sediment samples is determined by the sieve method for the coarse fractions and by the pipette method, based on the 'Stokes' sedimentation rates, for the fine fractions. Results from the two methods are compared with results from laser diffraction size

  10. Radiotherapy of brain metastases and glioblastomas in elderly patients; Radiotherapie des metastases cerebrales et des glioblastomes chez le sujet age

    Energy Technology Data Exchange (ETDEWEB)

    Lauche, O.; Kerr, C.; Riou, O.; Dhermain, F. [Institut Gustave-Roussy, Villejuif (France)

    2011-10-15

    As the occurrence of malignant gliomas and brain metastases is increasing in elderly people, the authors report the definition of an optimal therapeutic strategy for these patients. For patients in good health condition, a prospective randomized showed a modest benefit of radiotherapy alone with respect to support cares in terms of survival. The radiotherapy scheme is discussed in terms of dose and number of fractions. It seems that the physiological age is a strong prognosis factor. Short communication

  11. Study of efficacy and toxicity of hypofractionated thoracic radiotherapy 17 gray in 2 fractions for palliation in advanced non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Arif, S.; Rasul, S.; Haider, N.; Mahmood, A.; Syed, A.S.; Nadeem, M.

    2012-01-01

    Objective: To determine the efficacy and toxicity of hypofractionated thoracic radiotherapy 17 Gray (Gy) in 2 fractions for palliation in advanced non-small-cell lung carcinoma. Study design: A quasi-experimental study. Place and duration of study: Oncology department, Combined Military Hospital, Rawalpindi, from 4th July 2008 to 4th Nov 2009. Material and Methods: Fifty four patients with histologically and/or cytologically confirmed unresectable stages III and IV non small cell lung cancer, with performance status 2 or 3 and expected survival > 2 months were treated with megavoltage radiation therapy 17 Gy in 2 fractions one week apart, with symptoms due to intrathoracic disease (cough, dyspnea and hemoptysis) and toxicity due to radiation therapy (dysphagia secondary to esophagitis) assessed as per common toxicity criteria adverse event version 3.0 on day 0 before treatment and day 30 after start of treatment. Results: Grades of cough, hemoptysis and dyspnea showed significant improvement after treatment (p<0.001). A total of 42.68% patients showed an improvement in grade of cough (23 out of 54 patients), 85.7% of patients showed improvement in grade of hemoptysis (36 out of 42 patients) and 55.65% patients showed improvement in grade of dyspnea (30 out of 54 patients). Twenty two point two percent patients (12 out of 54) showed increase in grade of dysphagia. Although, there was a statistically significant increase in grade of dysphagia after treatment but it was limited to grade 1 and 2 only. Considering that no patient had grade 3 or 4 dysphagia, this toxicity was acceptable. Conclusion: Based on our results hypofractionated thoracic radiotherapy, 17 Gy in 2 fractions, is effective with acceptable toxicity in palliation in advanced non small cell lung cancer and is recommended as it will result in shorter duration of hospital stay and low hospital stay charges. (author)

  12. Hyperfractionated or accelerated radiotherapy in head and neck cancer: a meta-analysis

    DEFF Research Database (Denmark)

    Bourhis, J.; Overgaard, Jens; Audry, H.

    2006-01-01

    BACKGROUND: Several trials have studied the role of unconventional fractionated radiotherapy in head and neck squamous cell carcinoma, but the effect of such treatment on survival is not clear. The aim of this meta-analysis was to assess whether this type of radiotherapy could improve survival. M...

  13. A randomized trial comparing hypofractionated and conventionally fractionated three-dimensional external-beam radiotherapy for localized prostate adenocarcinoma. A report on acute toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Norkus, Darius; Miller, Albert; Kurtinaitis, Juozas; Valuckas, Konstantinas Povilas [Dept. of Radiotherapy, Inst. of Oncology, Vilnius Univ. (Lithuania); Haverkamp, Uwe [Dept. of Radiology, Clemenshospital, Muenster (Germany); Popov, Sergey [Dept. of Radiotherapy, Riga Eastern Hospital, Latvian Oncology Center, Riga (Latvia); Prott, Franz-Josef [Inst. of Radiology and Radiotherapy (RNS), St. Josefs Hospital, Wiesbaden (Germany)

    2009-11-15

    Purpose: to compare acute gastrointestinal (GI) and genitourinary (GU) toxicity between patient groups with localized prostate adenocarcinoma, treated with conventionally fractionated (CFRT) and hypofractionated (HFRT) three-dimensional conformal external-beam radiotherapy (3D-CRT). Patients and methods: 91 patients were enrolled into a randomized study with a minimum follow-up of 3 months. 44 men in the CFRT arm were irradiated with 74 Gy in 37 fractions at 2 Gy per fraction for 7.5 weeks. 47 men in the HFRT arm were treated with 57 Gy in 17 fractions for 3.5 weeks, given as 13 fractions of 3 Gy plus four fractions of 4.5 Gy. The clinical target volume (CTV) included the prostate and the base of seminal vesicles. The CTV-to-PTV (planning target volume) margin was 8-10 mm. Study patients had portal imaging and/or simulation performed on the first fractions and repeated at least weekly. Results: no acute grade 3 or 4 toxicities were observed. The grade 2 GU acute toxicity proportion was significantly lower in the HFRT arm: 19.1% versus 47.7% ({chi}{sup 2}-test, p = 0.003). The grade 2 GU acute toxicity-free survival was significantly better in the HFRT arm (log-rank test, p = 0.008). The median duration of overall GI acute toxicity was shorter with HFRT: 3 compared to 6 weeks with CFRT (median test, p = 0.017). Conclusion: in this first evaluation, the HFRT schedule is feasible and induces acceptable or even lower acute toxicity compared with the toxicities in the CFRT schedule. Extended follow-up is needed to justify this fractionation schedule's safety in the long term. (orig.)

  14. Hippocampal Dosimetry Predicts Neurocognitive Function Impairment After Fractionated Stereotactic Radiotherapy for Benign or Low-Grade Adult Brain Tumors

    International Nuclear Information System (INIS)

    Gondi, Vinai; Hermann, Bruce P.; Mehta, Minesh P.; Tomé, Wolfgang A.

    2013-01-01

    Purpose: To prospectively evaluate the association between hippocampal dose and long-term neurocognitive function (NCF) impairment for benign or low-grade adult brain tumors treated with fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Adult patients with benign or low-grade adult brain tumors were treated with FSRT per institutional practice. No attempt was made to spare the hippocampus. NCF testing was conducted at baseline and 18 months follow-up, on a prospective clinical trial. Regression-based standardized z scores were calculated by using similar healthy control individuals evaluated at the same test–retest interval. NCF impairment was defined as a z score ≤−1.5. After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas, dose–volume histograms were generated for the left and right hippocampi and for the composite pair. Biologically equivalent doses in 2-Gy fractions (EQD 2 ) assuming an α/β ratio of 2 Gy were computed. Fisher’s exact test and binary logistic regression were used for univariate and multivariate analyses, respectively. Dose–response data were fit to a nonlinear model. Results: Of 29 patients enrolled in this trial, 18 completed both baseline and 18-month NCF testing. An EQD 2 to 40% of the bilateral hippocampi >7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List (WMS-WL) delayed recall (odds ratio [OR] 19.3; p = 0.043). The association between WMS-WL delayed recall and EQD 2 to 100% of the bilateral hippocampi >0.0 Gy trended to significance (OR 14.8; p = 0.068). Conclusion: EQD 2 to 40% of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low-grade adult brain tumors. Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold, patients should be enrolled in

  15. Hippocampal Dosimetry Predicts Neurocognitive Function Impairment After Fractionated Stereotactic Radiotherapy for Benign or Low-Grade Adult Brain Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Gondi, Vinai [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Hermann, Bruce P. [Department of Neurology, University of Wisconsin, Madison, WI (United States); Mehta, Minesh P. [Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL (United States); Tome, Wolfgang A., E-mail: tome@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Department of Biomedical Engineering, University of Wisconsin, Madison, WI (United States)

    2012-07-15

    Purpose: To prospectively evaluate the association between hippocampal dose and long-term neurocognitive function (NCF) impairment for benign or low-grade adult brain tumors treated with fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Adult patients with benign or low-grade adult brain tumors were treated with FSRT per institutional practice. No attempt was made to spare the hippocampus. NCF testing was conducted at baseline and 18 months follow-up, on a prospective clinical trial. Regression-based standardized z scores were calculated by using similar healthy control individuals evaluated at the same test-retest interval. NCF impairment was defined as a z score {<=}-1.5. After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas, dose-volume histograms were generated for the left and right hippocampi and for the composite pair. Biologically equivalent doses in 2-Gy fractions (EQD{sub 2}) assuming an {alpha}/{beta} ratio of 2 Gy were computed. Fisher's exact test and binary logistic regression were used for univariate and multivariate analyses, respectively. Dose-response data were fit to a nonlinear model. Results: Of 29 patients enrolled in this trial, 18 completed both baseline and 18-month NCF testing. An EQD{sub 2} to 40% of the bilateral hippocampi >7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List (WMS-WL) delayed recall (odds ratio [OR] 19.3; p = 0.043). The association between WMS-WL delayed recall and EQD{sub 2} to 100% of the bilateral hippocampi >0.0 Gy trended to significance (OR 14.8; p = 0.068). Conclusion: EQD{sub 2} to 40% of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low-grade adult brain tumors. Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold

  16. Hippocampal Dosimetry Predicts Neurocognitive Function Impairment After Fractionated Stereotactic Radiotherapy for Benign or Low-Grade Adult Brain Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Gondi, Vinai [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Hermann, Bruce P. [Department of Neurology, University of Wisconsin, Madison, WI (United States); Mehta, Minesh P. [Department of Radiation Oncology, Northwestern University Feinberg School of Medicine, Chicago, IL (United States); Tome, Wolfgang A., E-mail: tome@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin, Madison, WI (United States); Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Department of Biomedical Engineering, University of Wisconsin, Madison, WI (United States)

    2013-02-01

    Purpose: To prospectively evaluate the association between hippocampal dose and long-term neurocognitive function (NCF) impairment for benign or low-grade adult brain tumors treated with fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Adult patients with benign or low-grade adult brain tumors were treated with FSRT per institutional practice. No attempt was made to spare the hippocampus. NCF testing was conducted at baseline and 18 months follow-up, on a prospective clinical trial. Regression-based standardized z scores were calculated by using similar healthy control individuals evaluated at the same test-retest interval. NCF impairment was defined as a z score {<=}-1.5. After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas, dose-volume histograms were generated for the left and right hippocampi and for the composite pair. Biologically equivalent doses in 2-Gy fractions (EQD{sub 2}) assuming an {alpha}/{beta} ratio of 2 Gy were computed. Fisher's exact test and binary logistic regression were used for univariate and multivariate analyses, respectively. Dose-response data were fit to a nonlinear model. Results: Of 29 patients enrolled in this trial, 18 completed both baseline and 18-month NCF testing. An EQD{sub 2} to 40% of the bilateral hippocampi >7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List (WMS-WL) delayed recall (odds ratio [OR] 19.3; p = 0.043). The association between WMS-WL delayed recall and EQD{sub 2} to 100% of the bilateral hippocampi >0.0 Gy trended to significance (OR 14.8; p = 0.068). Conclusion: EQD{sub 2} to 40% of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low-grade adult brain tumors. Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold

  17. Hippocampal Dosimetry Predicts Neurocognitive Function Impairment After Fractionated Stereotactic Radiotherapy for Benign or Low-Grade Adult Brain Tumors

    International Nuclear Information System (INIS)

    Gondi, Vinai; Hermann, Bruce P.; Mehta, Minesh P.; Tomé, Wolfgang A.

    2012-01-01

    Purpose: To prospectively evaluate the association between hippocampal dose and long-term neurocognitive function (NCF) impairment for benign or low-grade adult brain tumors treated with fractionated stereotactic radiotherapy (FSRT). Methods and Materials: Adult patients with benign or low-grade adult brain tumors were treated with FSRT per institutional practice. No attempt was made to spare the hippocampus. NCF testing was conducted at baseline and 18 months follow-up, on a prospective clinical trial. Regression-based standardized z scores were calculated by using similar healthy control individuals evaluated at the same test–retest interval. NCF impairment was defined as a z score ≤−1.5. After delineation of the bilateral hippocampi according to the Radiation Therapy Oncology Group contouring atlas, dose–volume histograms were generated for the left and right hippocampi and for the composite pair. Biologically equivalent doses in 2-Gy fractions (EQD 2 ) assuming an α/β ratio of 2 Gy were computed. Fisher’s exact test and binary logistic regression were used for univariate and multivariate analyses, respectively. Dose–response data were fit to a nonlinear model. Results: Of 29 patients enrolled in this trial, 18 completed both baseline and 18-month NCF testing. An EQD 2 to 40% of the bilateral hippocampi >7.3 Gy was associated with impairment in Wechsler Memory Scale-III Word List (WMS-WL) delayed recall (odds ratio [OR] 19.3; p = 0.043). The association between WMS-WL delayed recall and EQD 2 to 100% of the bilateral hippocampi >0.0 Gy trended to significance (OR 14.8; p = 0.068). Conclusion: EQD 2 to 40% of the bilateral hippocampi greater than 7.3 Gy is associated with long-term impairment in list-learning delayed recall after FSRT for benign or low-grade adult brain tumors. Given that modern intensity-modulated radiotherapy techniques can reduce the dose to the bilateral hippocampi below this dosimetric threshold, patients should be enrolled in

  18. Efficacy of soluble glycoprotein fraction from Allium sativum purified by size exclusion chromatography on murine Schistosomiasis mansoni.

    Science.gov (United States)

    Aly, Ibrahim; Taher, Eman E; El-Sayed, Hoda; Mohammed, Faten A; ELnain, Gehan; Hamad, Rabab S; Bayoumy, Elsayed M

    2017-06-01

    In this work, the efficiency of crude MeOH extracts and soluble glycoprotein fraction of Allium sativum purified by size-exclusion chromatography (SEC) on parasitological, histopathological and some biochemical parameters in Schistosoma mansoni infected mice were investigated. Animals were infected by tail immersion with 100 cercariae/each mouse and divided into five groups in addition to the normal control. The results revealed a significant decrease in mean worm burden in all treated mice especially in the group treated with soluble glycoprotein fraction of A. sativum as compared to infected non-treated control with the disappearance of female worms. Administration of the studied extracts revealed remarkable amelioration in the levels of all the measured parameters in S. mansoni infected mice. In addition, treatment of mice with crude A. sativum MeOH extract and soluble glycoprotein fraction of A. sativum decreased significantly the activities of studied enzymes as compared to the infected untreated group. The highest degrees of enhancement in pathological changes was observed in the treated one with soluble glycoprotein fraction of A. sativum compared to the infected group represented by small sized, late fibro-cellular granuloma, the decrease in cellular constituents and degenerative changes in eggs. In conclusion, A. sativum treatment had effective schistosomicidal activities, through reduction of worm burden and tissue eggs, especially when it was given in purified glycoprotein fraction. Moreover, the soluble glycoprotein fraction of A. sativum largely modulates both the size and the number of granulomas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Radiotherapy of invasive breast cancer: French national guidelines

    International Nuclear Information System (INIS)

    Besnard, S.; Mazeau-Woynar, V.; Verdoni, L.; Cutuli, B.; Fourquet, A.; Giard, S.; Hennequin, C.; Leblanc-Onfroy, M.

    2012-01-01

    The French National Cancer Institute (INCa) and Societe francaise de senologie et pathologie mammaire (SFSPM), in collaboration with a multidisciplinary experts group, have published the French national clinical practice guidelines on a selection of 11 currently debated questions regarding the management of invasive breast cancer. Those guidelines are based on a comprehensive analysis of the current published evidence dealing with those issues, secondly reviewed by 100 reviewers. Radiotherapy was concerned by five of the 11 questions: indications for the boost after whole gland irradiation; hypo-fractionated radiotherapy; partial breast irradiation; indications for mammary internal nodes irradiation, and indications of radiotherapy after neo-adjuvant chemotherapy. (authors)

  20. Single-dose radiotherapy for painful bone metastases

    International Nuclear Information System (INIS)

    Kal, H.B.

    1999-01-01

    Background: External beam radiotherapy is frequently applied for palliative treatment of painful bone lesions with a variety of fractionation schemes. There is a continuous interest to administer only 1 or a few dose fractions for inducing pain relief. Methods: A review of the literature was made with the aim to determine whether a treatment can be deduced that is simple and effective. The linear-quadratic (L-Q) concept was applied to compare reported therapy schemes which each other for the iso-effect pain relief. Results: Single-dose and fractionated radiotherapy resulted in partial or complete pain relief in about 80% of the patients. Complete responses have been observed in about 43% of the patients. For patients responding to treatment, the duration of pain relief is at least 3 to 4 months with reported duration of up to 1 year or even longer. Conclusion: Based on this review of literature data concerning randomized trials a treatment with a single dose of 8 Gy is effective for inducing pain relief. (orig.) [de

  1. Improvement of Gold Leaching from a Refractory Gold Concentrate Calcine by Separate Pretreatment of Coarse and Fine Size Fractions

    Directory of Open Access Journals (Sweden)

    Qian Li

    2017-05-01

    Full Text Available A total gold extraction of 70.2% could only be reached via direct cyanidation from a refractory As-, S- and C-bearing gold concentrate calcine, and the gold extraction varied noticeably with different size fractions. The reasons for unsatisfactory gold extraction from the calcine were studied through analyses of chemical composition, chemical phase and SEM-EDS of different sizes of particles. It was found that a significant segregation of compositions occurred during the grinding of gold ore before flotation. As a result, for the calcine obtained after oxidative roasting, the encapsulation of gold by iron oxides was easily engendered in finer particles, whilst in coarser particles the gold encapsulation by silicates was inclined to occur likely due to melted silicates blocking the porosity of particles. The improvement of gold leaching from different size fractions was further investigated through pretreatments with alkali washing, acid pickling or sulfuric acid curing-water leaching. Finally, a novel process was recommended and the total gold extraction from the calcine could be increased substantially to 93.6% by the purposeful pretreatment with alkali washing for the relatively coarse size fraction (+37 μm and sulfuric acid curing–water leaching for the fine size fraction (−37 μm.

  2. Scattered fractions of dose from 18 and 25 MV X-ray radiotherapy linear accelerators

    International Nuclear Information System (INIS)

    Shobe, J.; Rodgers, J.E.; Taylor, P.L.; Jackson, J.; Popescu, G.

    1996-01-01

    Over the years, measurements have been made at a few energies to estimate the scattered fraction of dose from the patient in medical radiotherapy operations. This information has been a useful aid in the determination of shielding requirements for these facilities. With these measurements, known characteriztics of photons, and various other known parameters, Monte Carlo codes are being used to calculate the scattered fractions and hence the shielding requirements for the photons of other energies commonly used in radiotherapeutic applications. The National Institute of Standards and Technology (NIST) acquired a Sagittaire medical linear accelerator (linac) which was previously located at the Yale-New Haven Hospital. This linac provides an X-ray beam of 25 MV photons and electron beams with energies up to 32 MeV. The housing on the gantry was permanently removed from the accelerator during installation. A Varian Clinac 1800 linear accelerator was used to produce the 18 MV photons at the Frederick Memorial Hospital Regional Cancer Therapy Center in Frederick, MD. This paper represents a study of the photon dose scattered from a patient in typical radiation treatment situations as it relates to the dose delivered at the isocenter in water. The results of these measurements will be compared to Monte Carlo calculations. Photon spectral measurements were not made at this time. Neutron spectral measurements were made on this Sagittaire machine in its previous location and that work was not repeated here, although a brief study of the neutron component of the 18 and 25 MV linacs was performed utilizing thermoluminescent dosimetry (TLD) to determine the isotropy of the neutron dose. (author)

  3. Study of the effect of misonidazole in conjunction with radiotherapy for the treatment of head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Henk, J.M.; Adams, G.E.; Ash, D. (Medical Research Council, London (UK))

    1984-07-01

    The effect of the hypoxic cell sensitiser misonidazole as an adjuvant to radiotherapy of head and neck cancer was tested in a randomised double blind study. Patients with squamous carcinoma of the upper alimentary and respiratory tract, excluding those with early disease with good prognosis, who were deemed suitable for radical radiotherapy and fit to receive the drug were entered. Two radiotherapy regimes were employed, 10 fractions in 3 weeks to a modal tumour dose of 4000-4500 cGy, and 20 fractions in 4 weeks to a modal tumour dose of 5000-5750 cGy. Participating radiotherapists opted for one of the schemes. Misonidazole or placebo capsules were administered 4 to 5 hours before each fraction of radiotherapy to a total of 11 to 13 g/m/sup 2/. 168 patients were treated with 10 fractions and 99 with 20 fractions, between March 1979 and November 1981, when entry was stopped because of the high incidence of drug toxicity and lack of benefit. The estimated hazard ratio for local control was 0.89, indicating a slight advantage to misonidazole, statistically insignificant (p = 0.5). Peripheral neuropathy occurred in 56 patients receiving misonidazole, and was more severe when treatment was given in 10 fractions.

  4. Every second cancer patient receives radiotherapy

    International Nuclear Information System (INIS)

    Ojala, A.

    1996-01-01

    Radiotherapy to treat cancer was given for the first time exactly one hundred years ago. Today, radiotherapy and surgery are the two main modes of treating cancer. One in two cancer patients receives radiotherapy at some point during the course of treatment for the disease. Radiotherapy is applied most commonly in cases where surgery is not possible. Moreover, these two modes of treatment are often used together to supplement each other. About half of new cancer cases detected today can be ordered. The estimate given by the EU for cancers cured is 45 per cent, which is divided between the various treatment modes as follows: surgery 22 %, radiotherapy 12 %, surgery plus radiotherapy 6 %, and drug therapy 6 %. In addition to curative treatment, radiotherapy plays a crucial role in palliative treatment, i.e. treatment that alleviates symptoms. The sensitivity of malignant tumours to radiotherapy varies over a wide range; the same is true for healthy tissues. Radiotherapy can only be used to cure a tumour that is more sensitive to radiation than the surrounding healthy tissue. The tumour must also be sufficiently small in size and limited to a relatively small area. (orig.)

  5. Radiotherapy in early stage dupuytren's contracture

    International Nuclear Information System (INIS)

    Adamietz, B.; Sauer, R.; Gruenert, J.

    2001-01-01

    Purpose: In early stage Dupuytren's contracture radiotherapy was applied to prevent disease progression. Long-term results and late toxicity of this treatment were evaluated in a retrospective analysis. Patients and Methods: Between 1982 and 1994, 99 patients (176 hands) received orthovoltage radiotherapy, which consisted of two courses with 5 x 3 Gy (total dose: 30 Gy, daily fractionated; 120 kV, 4 mm Al), separated by a 6 to 8-week pause. The Dupuytren's contracture was staged according to the classification of Tubiana et al. The long-term outcome was analyzed at last follow-up between July and November 1999. The median follow-up was 10 years (range 7-18 years). Late toxicity was assessed using the LENT-SOMA criteria. Results: In Stage N 84% and Stage N/I 67% of cases remained stable. 65% of the cases in Stage I and 83% in Stage II showed progressive nodules and cords. In case of progression we saw no complications after a second radiotherapy or salvage operation. Conclusion: Radiotherapy effectively prevents disease progression for early stage Dupuytren's contracture (Stage N, N/I). Moreover, in case of disease progression despite radiotherapy salvage surgery is still feasible. (orig.) [de

  6. Extracranial stereotactic radiotherapy: preliminary results with the CyberKnife.

    Science.gov (United States)

    Lartigau, Eric; Mirabel, Xavier; Prevost, Bernard; Lacornerie, Thomas; Dubus, Francois; Sarrazin, Thierry

    2009-04-01

    In the field of radiation oncology, equipment for fractionated radiotherapy and single-dose radiosurgery has become increasingly accurate, together with the introduction of robotized treatments. A robot is a device that can be programmed to carry out accurate, repeated and adjusted tasks in a given environment. Treatment of extracranial lesions involves taking into account organ mobility (tumor and healthy tissue) whilst retaining the ability to stereotactically locate the target. New imaging techniques (single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), positron emission tomography (PET)) provide further relevant information to slice images (computed tomography (CT) scans, MRI) for target definition. Hypo-fractionated treatments can only be used for curative treatment if the target is accurately defined and tracked during treatment. The CyberKnife is a non-invasive system of radiosurgery and fractionated stereotactic radiotherapy. For intracranial lesions treated by single-dose radiosurgery, it has been used to treat meningioma, acoustic neuromas, pituitary adenoma, metastases, arteriovenous malformations and refractory pain (trigeminal neuralgia). More than 10,000 patients have been treated worldwide. Currently, the most significant developments are in the field of extracranial stereotactic radiotherapy (lung, liver, reirradiation, prostate, etc.). Clinical results obtained in the CyberKnife Nord-Ouest program after 1 year of experience are presented. Copyright 2009 S. Karger AG, Basel.

  7. Concomitant boost radiotherapy for muscle invasive bladder cancer

    Energy Technology Data Exchange (ETDEWEB)

    Pos, Floris J; Tienhoven, Geertjan van; Hulshof, Maarten C.C.M.; Koedooder, Kees; Gonzalez Gonzalez, Dionisio

    2003-07-01

    Purpose: To evaluate the feasibility and efficacy of a concomitant partial bladder boost schedule in radiotherapy for invasive bladder cancer, coupling a limited boost volume with shortening of the overall treatment time. Methods and materials: Between 1994 and 1999, 50 patients with a T2-T4 N0M0 transitional cell carcinoma of the bladder received radiotherapy delivered in a short overall treatment time with a concomitant boost technique. With this technique a dose of 40 Gy in 2-Gy fractions was administered to the small pelvis with a concomitant boost limited to the bladder tumor area plus margin of 15 Gy in fractions of 0.75 Gy. The total tumor dose was 55 Gy in 20 fractions in 4 weeks. Toxicity was scored according to EORTC/RTOG toxicity criteria. Results: The feasibility of the treatment was good. Severe acute toxicity {>=}G3 was observed in seven patients (14%). Severe late toxicity {>=}G3 was observed in six patients (13%). Thirty-seven patients (74%) showed a complete and five (10 %) a partial remission after treatment. The actuarial 3-year freedom of local progression was 55%. Conclusion: In external radiotherapy for muscle invasive bladder cancer a concomitant boost technique coupling a partial bladder boost with shortening of the overall treatment time provides a high probability of local control with acceptable toxicity.

  8. Concomitant boost radiotherapy for muscle invasive bladder cancer

    International Nuclear Information System (INIS)

    Pos, Floris J.; Tienhoven, Geertjan van; Hulshof, Maarten C.C.M.; Koedooder, Kees; Gonzalez Gonzalez, Dionisio

    2003-01-01

    Purpose: To evaluate the feasibility and efficacy of a concomitant partial bladder boost schedule in radiotherapy for invasive bladder cancer, coupling a limited boost volume with shortening of the overall treatment time. Methods and materials: Between 1994 and 1999, 50 patients with a T2-T4 N0M0 transitional cell carcinoma of the bladder received radiotherapy delivered in a short overall treatment time with a concomitant boost technique. With this technique a dose of 40 Gy in 2-Gy fractions was administered to the small pelvis with a concomitant boost limited to the bladder tumor area plus margin of 15 Gy in fractions of 0.75 Gy. The total tumor dose was 55 Gy in 20 fractions in 4 weeks. Toxicity was scored according to EORTC/RTOG toxicity criteria. Results: The feasibility of the treatment was good. Severe acute toxicity ≥G3 was observed in seven patients (14%). Severe late toxicity ≥G3 was observed in six patients (13%). Thirty-seven patients (74%) showed a complete and five (10 %) a partial remission after treatment. The actuarial 3-year freedom of local progression was 55%. Conclusion: In external radiotherapy for muscle invasive bladder cancer a concomitant boost technique coupling a partial bladder boost with shortening of the overall treatment time provides a high probability of local control with acceptable toxicity

  9. Standard-Fractionated Radiotherapy for Optic Nerve Sheath Meningioma: Visual Outcome Is Predicted by Mean Eye Dose

    Energy Technology Data Exchange (ETDEWEB)

    Abouaf, Lucie [Neuro-Ophthalmology Unit, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); Girard, Nicolas [Radiotherapy-Oncology Department, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon (France); Claude Bernard University, Lyon (France); Lefort, Thibaud [Neuro-Radiology Department, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); D' hombres, Anne [Claude Bernard University, Lyon (France); Tilikete, Caroline; Vighetto, Alain [Neuro-Ophthalmology Unit, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); Claude Bernard University, Lyon (France); Mornex, Francoise, E-mail: francoise.mornex@chu-lyon.fr [Claude Bernard University, Lyon (France)

    2012-03-01

    Purpose: Radiotherapy has shown its efficacy in controlling optic nerve sheath meningiomas (ONSM) tumor growth while allowing visual acuity to improve or stabilize. However, radiation-induced toxicity may ultimately jeopardize the functional benefit. The purpose of this study was to identify predictive factors of poor visual outcome in patients receiving radiotherapy for ONSM. Methods and Materials: We conducted an extensive analysis of 10 patients with ONSM with regard to clinical, radiologic, and dosimetric aspects. All patients were treated with conformal radiotherapy and subsequently underwent biannual neuroophthalmologic and imaging assessments. Pretreatment and posttreatment values of visual acuity and visual field were compared with Wilcoxon's signed rank test. Results: Visual acuity values significantly improved after radiotherapy. After a median follow-up time of 51 months, 6 patients had improved visual acuity, 4 patients had improved visual field, 1 patient was in stable condition, and 1 patient had deteriorated visual acuity and visual field. Tumor control rate was 100% at magnetic resonance imaging assessment. Visual acuity deterioration after radiotherapy was related to radiation-induced retinopathy in 2 patients and radiation-induced mature cataract in 1 patient. Study of radiotherapy parameters showed that the mean eye dose was significantly higher in those 3 patients who had deteriorated vision. Conclusions: Our study confirms that radiotherapy is efficient in treating ONSM. Long-term visual outcome may be compromised by radiation-induced side effects. Mean eye dose has to be considered as a limiting constraint in treatment planning.

  10. Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy.

    Science.gov (United States)

    Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

    2016-02-27

    Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV

  11. Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy

    International Nuclear Information System (INIS)

    Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

    2016-01-01

    Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the non-target breast tissue volume (NTBTV) receives a high dose. In the context of APBI, non-coplanar beams could spare the NTBTV more efficiently. This study evaluates the dosimetric benefit of using the Cyberknife (CK) for APBI in comparison to IMRT (Tomotherapy) and three dimensional conformal radiotherapy (3D-CRT). The possibility of using surgical clips, implanted during surgery, to track target movements is investigated first. A phantom of a female thorax was designed in-house using the measurements of 20 patients. Surgical clips of different sizes were inserted inside the breast. A treatment plan was delivered to the mobile and immobile phantom. The motion compensation accuracy was evaluated using three radiochromic films inserted inside the breast. Three dimensional conformal radiotherapy (3D-CRT), Tomotherapy (TOMO) and CK treatment plans were calculated for 10 consecutive patients who received APBI in Lille. To ensure a fair comparison of the three techniques, margins applied to the CTV were set to 10 mm. However, a second CK plan was prepared using 3 mm margins to evaluate the benefits of motion compensation. Only the larger clips (VITALITEC Medium-Large) could be tracked inside the larger breast (all gamma indices below 1 for 1 % of the maximum dose and 1 mm). All techniques meet the guidelines defined in the NSABP/RTOG and SHARE protocols. As the applied dose volume constraints are very strong, insignificant dosimetric differences exist between techniques regarding the PTV

  12. Fractionated Stereotactic Radiotherapy in Patients With Optic Nerve Sheath Meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Paulsen, Frank, E-mail: frank.paulsen@med.uni-tuebingen.de [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Doerr, Stefan [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Wilhelm, Helmut [Department of Ophthalmology, University of Tuebingen, Tuebingen (Germany); Becker, Gerd [Department of Radiation Oncology, Klinik am Eichert, Goeppingen (Germany); Bamberg, Michael [Department of Radiation Oncology, University of Tuebingen, Tuebingen (Germany); Classen, Johannes [Department of Radiation Oncology, St. Vincentius-Kliniken, Karlsruhe (Germany)

    2012-02-01

    Purpose: To evaluate the effectiveness of fractionated stereotactic radiotherapy (SFRT) in the treatment of optic nerve sheath meningioma (ONSM). Methods and Materials: Between 1993 and 2005, 109 patients (113 eyes) with primary (n = 37) or secondary (n = 76) ONSM were treated according to a prospective protocol with SFRT to a median dose of 54 Gy. All patients underwent radiographic, ophthalmologic, and endocrine analysis before and after SFRT. Radiographic response, visual control, and late side effects were endpoints of the analysis. Results: Median time to last clinical, radiographic, and ophthalmologic follow up was 30.2 months (n = 113), 42.7 months (n = 108), and 53.7 months (n = 91), respectively. Regression of the tumor was observed in 5 eyes and progression in 4 eyes, whereas 104 remained stable. Visual acuity improved in 12, deteriorated in 11, and remained stable in 68 eyes. Mean visual field defects reduced from 33.6% (n = 90) to 17.8% (n = 56) in ipsilateral and from 10% (n = 94) to 6.7% (n = 62) in contralateral eyes. Ocular motility improved in 23, remained stable in 65, and deteriorated in 3 eyes. Radiographic tumor control was 100% at 3 years and 98% at 5 years. Visual acuity was preserved in 94.8% after 3 years and in 90.9% after 5 years. Endocrine function was normal in 90.8% after 3 years and in 81.3% after 5 years. Conclusions: SFRT represents a highly effective treatment for ONSM. Interdisciplinary counseling of the patients is recommended. Because of the high rate of preservation of visual acuity we consider SFRT the standard approach for the treatment of ONSM. Prolonged observation is warranted to more accurately assess late visual impairment. Moderate de-escalation of the radiation dose might improve the preservation of visual acuity and pituitary gland function.

  13. Acoustic neuromas: single dose vs fractionated therapy

    International Nuclear Information System (INIS)

    Fuss, M.; Debus, J.; Lohr, F.; Engenhart-Cabillic, R.; Wannenmacher, M.

    1997-01-01

    Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

  14. Estimating the number of fractions by tumour site for European countries in 2012 and 2025: An ESTRO-HERO analysis.

    Science.gov (United States)

    Borras, Josep M; Grau, Cai; Corral, Julieta; Wong, Karen; Barton, Michael B; Ferlay, Jacques; Bray, Freddie; Lievens, Yolande

    2018-02-01

    The optimal number of radiotherapy fractions is a relevant input for planning resource needs. An estimation of the total number of fractions by country and tumour site is assessed for 2012 and 2025. European cancer incidence data by tumour site and country for 2012 and 2025 were extracted from the GLOBOCAN database. Incidence and stage data were introduced in the Australian Collaboration for Cancer Outcomes Research and Evaluation (CCORE) model, producing an evidence-based proportion of incident cases with an indication for radiotherapy and fractions by indication. An indication was defined as a clinical situation in which radiotherapy was the treatment of choice. The total number of fractions if radiotherapy was given according to guidelines to all patients with an indication in Europe was estimated to be 30 million for 2012; with a forecasted increase of 16.1% by 2025, yet with differences by country and tumour. The average number of fractions per course was 17.6 with a small range of differences following stage at diagnosis. Among the treatments with radical intent the average was 24 fractions, while it decreased to 2.5 among palliative treatments. An increase in the total number of fractions is expected in many European countries in the coming years following the trends in cancer incidence. In planning radiotherapy resources, these increases should be balanced to the evolution towards hypofractionation, along with increased complexity and quality assurance. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Ball mill tool for crushing coffee and cocoa beans base on fraction size sieving results

    Science.gov (United States)

    Haryanto, B.; Sirait, M.; Azalea, M.; Alvin; Cahyani, S. E.

    2018-02-01

    Crushing is one of the operation units that aimed to convert the size of solid material to be smoother particle’s size. The operation unit that can be used in this crushing is ball mill. The purpose of this study is to foresee the effect of raw material mass, grinding time, and the number of balls that are used in the ball mill tool related to the amount of raw material of coffee and cocoa beans. Solid material that has become smooth is then sieved with sieve mesh with size number: 50, 70, 100, and 140. It is in order to obtain the mass fraction that escaped from each sieve mesh. From the experiment, it can be concluded that mass percentage fraction of coffee powder is bigger than cocoa powder that escaped from the mesh. Hardness and humidity of coffee beans and cocoa beans have been the important factors that made coffee beans is easier to be crushed than cocoa beans.

  16. Heavy metal pollution decreases microbial abundance, diversity and activity within particle-size fractions of a paddy soil.

    Science.gov (United States)

    Chen, Junhui; He, Feng; Zhang, Xuhui; Sun, Xuan; Zheng, Jufeng; Zheng, Jinwei

    2014-01-01

    Chemical and microbial characterisations of particle-size fractions (PSFs) from a rice paddy soil subjected to long-term heavy metal pollution (P) and nonpolluted (NP) soil were performed to investigate whether the distribution of heavy metals (Cd, Cu, Pb and Zn) regulates microbial community activity, abundance and diversity at the microenvironment scale. The soils were physically fractionated into coarse sand, fine sand, silt and clay fractions. Long-term heavy metal pollution notably decreased soil basal respiration (a measurement of the total activity of the soil microbial community) and microbial biomass carbon (MBC) across the fractions by 3-45% and 21-53%, respectively. The coarse sand fraction was more affected by pollution than the clay fraction and displayed a significantly lower MBC content and respiration and dehydrogenase activity compared with the nonpolluted soils. The abundances and diversities of bacteria were less affected within the PSFs under pollution. However, significant decreases in the abundances and diversities of fungi were noted, which may have strongly contributed to the decrease in MBC. Sequencing of denaturing gradient gel electrophoresis bands revealed that the groups Acidobacteria, Ascomycota and Chytridiomycota were clearly inhibited under pollution. Our findings suggest that long-term heavy metal pollution decreased the microbial biomass, activity and diversity in PSFs, particularly in the large-size fractions. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  17. Palliative radiotherapy for multiple myeloma

    International Nuclear Information System (INIS)

    Furusawa, Mitsuhiro; Baba, Yuji; Murakami, Ryuji; Yokoyama, Toshimi; Nishimura, Ryuichi; Uozumi, Hideaki; Takada, Chitose; Takahashi, Mutsumasa

    1995-01-01

    This study reviews the experience of palliative radiotherapy to patients with multiple myeloma to define the optimal dose for pain relief. The records of 31 patients (66 sites) with multiple myeloma irradiated for palliation at Kumamoto University hospital between 1985 and 1994 were reviewed. Total dose ranged from 8 to 50 Gy, with a mean of 32.2 Gy. Symptoms included pain (78.1%), neurological abnormalities (28.1%), and palpable masses (34.3%). Symptomatic remission was obtained in 45 of 46 evaluable sites (97.8%). Complete remission of symptoms were obtained in 28.3%, and partial remission in 69.6%. According to fraction size, there was no significant difference between 3-5 Gy and 1.8-2 Gy. The incidence of complete remission increased when a total dose of more than 20 Gy was given. When the quality of life is considered, hypofractionation was recommended for the palliative radiation therapy of multiple myeloma. (author)

  18. Hypofractionated stereotactic radiotherapy in five daily fractions for post-operative surgical cavities in brain metastases patients with and without prior whole brain radiation.

    Science.gov (United States)

    Al-Omair, Ameen; Soliman, Hany; Xu, Wei; Karotki, Aliaksandr; Mainprize, Todd; Phan, Nicolas; Das, Sunit; Keith, Julia; Yeung, Robert; Perry, James; Tsao, May; Sahgal, Arjun

    2013-12-01

    Our purpose was to report efficacy of hypofractionated cavity stereotactic radiotherapy (HCSRT) in patients with and without prior whole brain radiotherapy (WBRT). 32 surgical cavities in 30 patients (20 patients/21 cavities had no prior WBRT and 10 patients/11 cavities had prior WBRT) were treated with image-guided linac stereotactic radiotherapy. 7 of the 10 prior WBRT patients had "resistant" local disease given prior surgery, post-operative WBRT and a re-operation, followed by salvage HCSRT. The clinical target volume was the post-surgical cavity, and a 2-mm margin applied as planning target volume. The median total dose was 30 Gy (range: 25-37.5 Gy) in 5 fractions. In the no prior and prior WBRT cohorts, the median follow-up was 9.7 months (range: 3.0-23.6) and 15.3 months (range: 2.9-39.7), the median survival was 23.6 months and 39.7 months, and the 1-year cavity local recurrence progression- free survival (LRFS) was 79 and 100%, respectively. At 18 months the LRFS dropped to 29% in the prior WBRT cohort. Grade 3 radiation necrosis occurred in 3 prior WBRT patients. We report favorable outcomes with HCSRT, and well selected patients with prior WBRT and "resistant" disease may have an extended survival favoring aggressive salvage HCSRT at a moderate risk of radiation necrosis.

  19. Distribution of artificial radionuclides in particle-size fractions of soil on fallout plumes of nuclear explosions.

    Science.gov (United States)

    Kabdyrakova, A M; Lukashenko, S N; Mendubaev, A T; Kunduzbayeva, A Ye; Panitskiy, A V; Larionova, N V

    2018-06-01

    In this paper are analyzed the artificial radionuclide distributions ( 137 Cs, 90 Sr, 241 Am, 239+240 Pu) in particle-size fractions of soils from two radioactive fallout plumes at the Semipalatinsk Test Site. These plumes were generated by a low-yield surface nuclear test and a surface non-nuclear experiment with insignificant nuclear energy release, respectively, and their lengths are approximately 3 and 0,65 km. In contrast with the great majority of similar studies performed in areas affected mainly by global fallout where adsorbing radionuclides such as Pu are mainly associated with the finest soil fractions, in this study it was observed that along both analyzed plumes the highest activity concentrations are concentrated in the coarse soil fractions. At the plume generated by the surface nuclear test, the radionuclides are concentrated mainly in the 1000-500 μm soil fraction (enrichment factor values ranging from 1.2 to 3.8), while at the plume corresponding to the surface non-nuclear test is the 500-250 μm soil fraction the enriched one by technogenic radionuclides (enrichment factor values ranging from 1.1 to 5.1). In addition, the activity concentration distributions among the different soil size fractions are similar for all radionuclides in both plumes. All the obtained data are in agreement with the hypothesis indicating that enrichment observed in the coarse fractions is caused by the presence of radioactive particles resulted from the indicated nuclear tests. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Results of three-dimensional conformal radiotherapy and thalidomide for advanced hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Hsu, Wei-Chung; Chung, Na-Na; Wang, Po-Ming; Ying, Kung-Shih; Shin, Jeng-Shiann; Chao, Che-Jen; Lin, Gau-De; Chan, Sue-Ching; Ting, Lai-Lei

    2006-01-01

    The purpose of this study was to evaluate the effectiveness of three-dimensional conformal radiotherapy and thalidomide in the treatment of advanced hepatocellular carcinoma. Between 1999 and 2003, 121 patients (mean age, 54.4±12.4 years; range, 20-81 years) with advanced hepatocellular carcinoma received three-dimensional conformal radiotherapy and thalidomide. Radiation was delivered in 1.5 Gy fractions twice daily for 5 days a week, for a total dose of 45-75 Gy. Mean treatment volume was 429.52±408.50 cm 3 (range, 26.89-2284.82 cm 3 ). Thalidomide was given concomitantly: 200 mg/day in 109 patients, 300 mg/day in 8 patients and 400 mg/day in 4 patients. Treatment responses, survival rates and factors affecting survival were analyzed. Treatment responses were observed in 61% of the patients. Liver cirrhosis (P=0.001) and tumor size (P=0.001) significantly affected the tumor responses. Overall survival at 6, 12 and 24 months was 84.8, 60.0 and 44.6%, respectively. On univariate analysis, liver cirrhosis (P=0.003), Karnofsky performance status (P=0.007), tumor size (P<0.001), portal vein tumor thrombosis (P<0.001) and alpha-fetoprotein level (P=0.003) were shown to significantly affect survival. On multivariate analysis, only thrombosis (P=0.039) and alpha-fetoprotein level (P=0.006) were shown to be factors affecting survival. Three-dimensional conformal radiotherapy with thalidomide seems to be effective in the treatment of advanced hepatocellular carcinoma. (author)

  1. Microbial communities in litter and soil - particles size fractionation, C- and N-pools and soil enzymes

    International Nuclear Information System (INIS)

    Stemmer, M.; Gerzabek, M.H.; Pichlmayer, F.; Kandeler, E.

    1995-08-01

    In this study we try to correlate C and N pool investigations to enzyme activities in particle size fractions of soils. Soil incubations in the lab (for one year) simulate two different conventional tillage treatments : (i) soil mixed with maize straw (GSF-mixed) and (ii) soil with maize straw lying on the top (home-mixed). The control soil is incubated without any amendment. The separation of the particle size fractions (2000 - 200 μm, 200 - 63 μm, 63 - 2 μm, 2 - 0.1 μm and 0.1 - 0 μm) is realized by a combination of wet-sieving and centrifugation. To disrupt aggregates we use a defined low-energy ultrasonication, which partly preserves microaggregates. The decomposition of organic C during the incubation can be observed clearly, the small amount of N in the added maize straw complicates the analysis. The isotopic measurements of δ13C and δ15N provide valuable additional informations in this context. Both enzymes, saccharase and xylanase, seem to react in a more sensitive way on the incorporation of the maize litter, than the chemical analysis of the pools. The saccharase activity, which seems to be a sensitive indicator for microbial biomass, shows different behaviour between the mix- and top-treatment. The xylanase activity is mainly located in the coarse sand fraction, this extracellular enzyme might be adsorbed by the particulate organic matter. The transfer of adhering coatings and small particles of the added maize to small sized particles during the fractionation procedure and the 'passive role' of the silt fraction, which could be due to the used method, are nonexpected results. (author)

  2. Randomized multicenter follow-up trial on the effect of radiotherapy for plantar fasciitis (painful heels spur) depending on dose and fractionation – a study protocol

    International Nuclear Information System (INIS)

    Holtmann, Henrik; Niewald, Marcus; Prokein, Benjamin; Graeber, Stefan; Ruebe, Christian

    2015-01-01

    An actual clinical trial showed the effect of low dose radiotherapy in painful heel spur (plantar fasciitis) with single doses of 1.0 Gy and total doses of 6.0 Gy applied twice weekly. Furthermore, a lot of animal experimental and in vitro data reveals the effect of lower single doses of 0.5 Gy which may be superior in order to ease pain and reduce inflammation in patients with painful heel spur. Our goal is therefore to transfer this experimentally found effect into a randomized multicenter trial. This was a controlled, prospective, two-arm phase III-multicenter trial. The standard arm consisted of single fractions of 1.0 Gy applied two times a week, for a total dose of 6.0 Gy (total therapy time: 3 weeks). The experimental arm consisted of single fractions of 0.5 Gy applied 3 times a week, for a total dose of 6.0 Gy (total therapy time: 4 weeks). Following a statistical power calculation, there were 120 patients for each investigation arm. The main inclusion criteria were: age > = 40 years, clinical and radiologically diagnosed painful heel spur (plantar fasciitis), and current symptoms for at least 6 months. The main exclusion criteria were: former local trauma, surgery or radiotherapy of the heel; pregnant or breastfeeding women; and a pre-existing severe psychiatric or psychosomatic disorder. After approving a written informed consent the patients are randomized by a statistician into one of the trial arms. After radiotherapy, the patients are seen after six weeks, after twelve weeks and then every twelve weeks up to 48 weeks. Additionally, they receive a questionnaire every six weeks after the follow-up examinations up to 48 weeks. The effect is measured using the visual analogue scale of pain (VAS), the calcaneodynia score according to Rowe and the SF-12 score. The primary endpoint is the pain relief three months after therapy. Patients of both therapy arms with an insufficient result are offered a second radiotherapy series applying the standard dose

  3. Radiotherapy in age-related macula degeneration

    International Nuclear Information System (INIS)

    Gripp, Stephan; Stammen, Johannes; Petersen, Claudia; Hartmann, Axel; Willers, Reinhart; Althaus, Christoph

    2002-01-01

    Purpose: To ascertain the benefit from radiotherapy in age-related macula degeneration in a single-arm longitudinal study. Methods and Materials: From 1997 to 1998, 39 patients with occult and 33 patients with classic choroidal neovascularization (CNV) were irradiated with 16 Gy. Fluorescein angiography and measurements of visual acuity were performed before and 3, 6, and 12 months after irradiation. Results: Complete follow-up data for 1 year were available from 69 patients. The mean patient age was 72 years (range 49-92). Vision decreased in 43, was stable in 18, and improved in 8 cases. The mean vision deteriorated significantly (p=0.02, Wilcoxon test), particularly within the first 3 months. Patients with occult CNV did significantly better than did those with classic CNV (p=0.03). The proportion of patients retaining vision ≥0.2 fell from 65% to 42% (p <0.01), for classic and occult CNV from 50% to 23%, and for occult CNV from 77% to 56% (p<0.02), respectively. CNV size increased in 30 patients and was stable in 38. Neither age (p=0.17) nor gender (p=0.21, chi-square test) influenced prognosis. Four patients reported transitional complaints. Conclusion: Low-dose fractionated radiotherapy with 16 Gy is well tolerated. However, vision and reading ability were not preserved in most patients

  4. Characterization of Time-Dependent Contact Angles for Oleic Acid Mixed Sands with Different Particle Size Fractions

    DEFF Research Database (Denmark)

    Wijewardana, Y. N. S.; Kawamoto, Ken; Komatsu, Toshiko

    2014-01-01

    ) mixed sands representing four different particle size fractions ranging from 0.105 to 0.84 mm. Initial soil-water contact angle (αi), and the time dependence of contact angle were measured by the sessile drop method. Results showed that the αi value for fine and middle sand fractions increased rapidly...... in contact angle (α), well captured the time dependence of α....

  5. Stereotactic radiotherapy and radiosurgery in pediatric patients: analysis of indications and outcome

    DEFF Research Database (Denmark)

    Mirza, Bilal; Mønsted, Anne; Jensen, Josephine Harding

    2010-01-01

    We describe indications, outcomes, and risk profiles of fractionated stereotactic radiotherapy (SRT) and single fraction "radiosurgery" (SRS) in pediatric patients compared to the adult population and evaluate the causal role of SRS and SRT in inducing new neurological complications....

  6. Arterial occlusive disease after radiotherapy

    International Nuclear Information System (INIS)

    Piedbois, P.; Mazeron, J.J.; Le Bourgeois, J.P.; Becquemin, J.P.; Blanc, I.; Lange, F.; Melliere, D.

    1990-01-01

    Fourteen cases of arterial occlusion or severe narrowing following radiotherapy are studied in order to assess the possible etiological role of such therapy in arterial lesion. Surgical results are also discussed in terms of long-term efficacy. The average time of occurrence after radiotherapy was 8 years post-radiotherapy. This series includes 7 supra-aortic trunk stenoses and 7 abdominal aorta trunk stenoses. The doses received in the volumes iradiated ranged from 47 to 70 Gy with standard fractionation. Association of atherosclerotic risk factors was present in 12 patients, but stenoses were usually confined to irradiated areas, and at imes occurred in uncommon sites. Surgical management included 11 by-passes, 2 endarterectomies and one percutaneous transluminal angioplasty. All patients experienced immediate and satisfactory functional improvements. Three patients were re-operated on because of the re-occlusion of the by-pass and graft infection. On the whole, stenoses in previously irradiated areas showed no particular difficulties for surgical treatment. It was concluded that radiotherapy seems to be a definite risk factor for arterial occlusion or narrowing, especially in association in association with atherosclerotic risk factors. (author). 45 refs.; 3 figs.; 2 tabs

  7. Ultrashort courses of adjuvant breast radiotherapy: wave of the future or a fool's errand?

    Science.gov (United States)

    Khan, Atif J; Dale, Roger G; Arthur, Douglas W; Haffty, Bruce G; Todor, Dorin A; Vicini, Frank A

    2012-04-15

    In accelerated partial breast irradiation (APBI), the most commonly used fractionation schemes include 340 or 385 centigrays delivered in a twice daily administration. A further progression of the APBI literature has been the recent interest in extremely short courses of adjuvant radiotherapy, usually delivered by intraoperative radiotherapy techniques. This newer area of single-fraction radiotherapy approaches remains highly contentious. In particular, the recently reported TARGIT trial has been the subject of both praise and scorn, and a critical examination of the trial data and the underlying hypotheses is warranted. Short-term outcomes of the related Italian ELIOT approach have also been reported. Although the assumptions of linear quadratic formalism are likely to hold true in the range of 2 to 8 grays, equating different schedules beyond this range is problematic. A major problem of current single-fraction approaches is that the treatment doses are chosen empirically, or are based on tolerability, or on the physical dose delivery characteristics of the chosen technology rather than radiobiological rationale. This review article summarizes the current data on ultrashort courses of adjuvant breast radiotherapy and highlights both the promise and the potential pitfalls of the abbreviated treatment. Copyright © 2011 American Cancer Society.

  8. Oxidative potential of size-fractionated atmospheric aerosol in urban and rural sites across Europe.

    Science.gov (United States)

    Shafer, Martin M; Hemming, Jocelyn D C; Antkiewicz, Dagmara S; Schauer, James J

    2016-07-18

    In this study we applied several assays, an in vitro rat alveolar macrophage model, a chemical ROS probe (DTT, dithiothreitol), and cytokine induction (TNFα) to examine relationships between PM-induced generation of reactive oxygen species (ROS) and PM composition, using a unique set of size-resolved PM samples obtained from urban and rural environments across Europe. From April-July 2012, we collected PM from roadside canyon, roadside motorway, and background urban sites in each of six European cities and from three rural sites spanning the continent. A Hi-Vol sampler was used to collect PM in three size classes (PM>7, PM7-3, PM3) and PM was characterized for total elements, and oxidative activity quantified in unfiltered and filtered PM extracts. We measured a remarkable uniformity in air concentrations of ROS and especially DTT activity across the continent. Only a 4-fold difference was documented for DTT across the urban sites and a similar variance was documented for ROS, implying that chemical drivers of oxidative activity are relatively similar between sites. The ROS and DTT specific activity was greater at urban background sites (and also rural sites) than at urban canyon locations. PM3 dominated the size distribution of both ROS activity (86% of total) and DTT activity (76% of total), reflecting both the large contribution of PM3 to total PM mass levels and importantly the higher specific oxidative activity of the PM3 in comparison with the larger particles. The soluble fraction of total activity was very high for DTT (94%) as well as for ROS (64%) in the PM3. However in the larger PM size fractions the contributions of the insoluble components became increasingly significant. The dominance of the insoluble PM drivers of activity was particularly evident in the TNFα data, where the insoluble contribution to cytokine production could be 100-fold greater than that from soluble components. ROS and DTT activity were strongly correlated in the PM3 (r = 0

  9. Hippocampal sparing radiotherapy for glioblastoma patients: a planning study using volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Hofmaier, Jan; Kantz, Steffi; Söhn, Matthias; Dohm, Oliver S.; Bächle, Stefan; Alber, Markus; Parodi, Katia; Belka, Claus; Niyazi, Maximilian

    2016-01-01

    The purpose of this study is to investigate the potential to reduce exposure of the contralateral hippocampus in radiotherapy for glioblastoma using volumetric modulated arc therapy (VMAT). Datasets of 27 patients who had received 3D conformal radiotherapy (3D-CRT) for glioblastoma with a prescribed dose of 60Gy in fractions of 2Gy were included in this planning study. VMAT plans were optimized with the aim to reduce the dose to the contralateral hippocampus as much as possible without compromising other parameters. Hippocampal dose and treatment parameters were compared to the 3D-CRT plans using the Wilcoxon signed-rank test. The influence of tumour location and PTV size on the hippocampal dose was investigated with the Mann–Whitney-U-test and Spearman’s rank correlation coefficient. The median reduction of the contralateral hippocampus generalized equivalent uniform dose (gEUD) with VMAT was 36 % compared to the original 3D-CRT plans (p < 0.05). Other dose parameters were maintained or improved. The median V30Gy brain could be reduced by 17.9 % (p < 0.05). For VMAT, a parietal and a non-temporal tumour localisation as well as a larger PTV size were predictors for a higher hippocampal dose (p < 0.05). Using VMAT, a substantial reduction of the radiotherapy dose to the contralateral hippocampus for patients with glioblastoma is feasible without compromising other treatment parameters. For larger PTV sizes, less sparing can be achieved. Whether this approach is able to preserve the neurocognitive status without compromising the oncological outcome needs to be investigated in the setting of prospective clinical trials

  10. Post-external radiotherapy hypothyroidism: 15 cases; Hypothyroidie apres radiotherapie externe. A propos de 15 cas

    Energy Technology Data Exchange (ETDEWEB)

    Kaffel, N.; Mnif, M.; Abid, M. [Centre Hospitalier Universitaire Hedi Chaker, Sfax (Tunisia); Daoud, J. [Centre Hospitalier Universitaire Habib Bourguiba, Sfax (Tunisia)

    2001-06-01

    Post-external radiotherapy hypothyroidism: 15 cases. Hypothyroidism frequency is estimated to be between 10 and 45% after radiotherapy alone, and 40 to 67% after radiotherapy associated with thyroidectomy. This hypothyroidism is infra-clinical in 60% of the cases. Our study concerned 15 cases of hypothyroidism after external radiotherapy delivered between and 1991 and 1999. An irradiation of the cervical, cerebral and thorax regions was indicated for different types of cancers. Larynx carcinoma epidermoid was the most frequent cancer (seven cases); the radiation treatment used cobalt 60 with conventional fractionation, i.e., 2 Gy per treatment, five treatments a week. In nine cases, the hypothyroidism was discovered during a systematic examination; it was clinically evident in the six remaining cases. Hypothyroidism appeared after an irradiation dose average of 50 Gy (extremes 30-65 Gy). The average duration of the irradiation was about 7 weeks and the hypothyroidism appeared in a mean 22 months. In all cases, the substituting treatment was initiated with a favorable progression. Faced with the risk of hypothyroidism, it is necessary to check patients who have undergone external irradiation of the neck. (authors)

  11. A method for detecting the presence of organic fraction in nucleation mode sized particles

    Directory of Open Access Journals (Sweden)

    P. Vaattovaara

    2005-01-01

    Full Text Available New particle formation and growth has a very important role in many climate processes. However, the overall knowlegde of the chemical composition of atmospheric nucleation mode (particle diameter, d<20 nm and the lower end of Aitken mode particles (d≤50 nm is still insufficient. In this work, we have applied the UFO-TDMA (ultrafine organic tandem differential mobility analyzer method to shed light on the presence of an organic fraction in the nucleation mode size class in different atmospheric environments. The basic principle of the organic fraction detection is based on our laboratory UFO-TDMA measurements with organic and inorganic compounds. Our laboratory measurements indicate that the usefulness of the UFO-TDMA in the field experiments would arise especially from the fact that atmospherically the most relevant inorganic compounds do not grow in subsaturated ethanol vapor, when particle size is 10 nm in diameter and saturation ratio is about 86% or below it. Furthermore, internally mixed particles composed of ammonium bisulfate and sulfuric acid with sulfuric acid mass fraction ≤33% show no growth at 85% saturation ratio. In contrast, 10 nm particles composed of various oxidized organic compounds of atmospheric relevance are able to grow in those conditions. These discoveries indicate that it is possible to detect the presence of organics in atmospheric nucleation mode sized particles using the UFO-TDMA method. In the future, the UFO-TDMA is expected to be an important aid to describe the composition of atmospheric newly-formed particles.

  12. Structural composition of organic matter in particle-size fractions of soils along a climo-biosequence in the main range of Peninsular Malaysia

    Science.gov (United States)

    Jafarzadeh-Haghighi, Amir Hossein; Shamshuddin, Jusop; Hamdan, Jol; Zainuddin, Norhazlin

    2016-09-01

    Information on structural composition of organic matter (OM) in particle-size fractions of soils along a climo-biosequence is sparse. The objective of this study was to examine structural composition and morphological characteristics of OM in particle-size fractions of soils along a climo-biosequence in order to better understand the factors and processes affecting structural composition of soil organic matter. To explore changes in structural composition of OM in soils with different pedogenesis, the A-horizon was considered for further analyses including particle-size fractionation, solid-state 13C nuclear magnetic resonance (NMR) spectroscopy and scanning electron microscopy (SEM). Due to the increase in the thickness of organic layer with increasing elevation, the A-horizon was situated at greater depth in soils of higher elevation. The relationship between relative abundances of carbon (C) structures and particle-size fractions was examined using principal component analysis (PCA). It was found that alkyl C (20.1-73.4%) and O-alkyl C (16.8-67.7%) dominated particle-size fractions. The proportion of alkyl C increased with increasing elevation, while O-alkyl C showed an opposite trend. Results of PCA confirmed this finding and showed the relative enrichment of alkyl C in soils of higher elevation. Increase in the proportion of alkyl C in 250-2000 μm fraction is linked to selective preservation of aliphatic compounds derived from root litter. SEM results showed an increase in root contribution to the 250-2000 μm fraction with increasing elevation. For the changes in structural composition of OM in particle-size fractions of soils along the studied climo-biosequence are attributed to site-specific differences in pedogenesis as a function of climate and vegetation.

  13. Clinical Usefulness of Implanted Fiducial Markers for Hypofractionated Radiotherapy of Prostate Cancer

    International Nuclear Information System (INIS)

    Choi, Young Min; Ahn, Sung Hwan; Lee, Hyung Hwan; Lee, Hyung Sik; Hur, Woo Joo; Yoon, Jin Han; Kim, Tae Hyo; Kim, Soo Dong; Yun, Seong Guk

    2011-01-01

    To assess the usefulness of implanted fiducial markers in the setup of hypofractionated radiotherapy for prostate cancer patients by comparing a fiducial marker matched setup with a pelvic bone match. Four prostate cancer patients treated with definitive hypofractionated radiotherapy between September 2009 and August 2010 were enrolled in this study. Three gold fiducial markers were implanted into the prostate and through the rectum under ultrasound guidance around a week before radiotherapy. Glycerin enemas were given prior to each radiotherapy planning CT and every radiotherapy session. Hypofractionated radiotherapy was planned for a total dose of 59.5 Gy in daily 3.5 Gy with using the Novalis system. Orthogonal kV X-rays were taken before radiotherapy. Treatment positions were adjusted according to the results from the fusion of the fiducial markers on digitally reconstructed radiographs of a radiotherapy plan with those on orthogonal kV X-rays. When the difference in the coordinates from the fiducial marker fusion was less than 1 mm, the patient position was approved for radiotherapy. A virtual bone matching was carried out at the fiducial marker matched position, and then a setup difference between the fiducial marker matching and bone matching was evaluated. Three patients received a planned 17-fractionated radiotherapy and the rest underwent 16 fractionations. The setup error of the fiducial marker matching was 0.94±0.62 mm (range, 0.09 to 3.01 mm; median, 0.81 mm), and the means of the lateral, craniocaudal, and anteroposterior errors were 0.39±0.34 mm, 0.46±0.34 mm, and 0.57±0.59 mm, respectively. The setup error of the pelvic bony matching was 3.15±2.03 mm (range, 0.25 to 8.23 mm; median, 2.95 mm), and the error of craniocaudal direction (2.29±1.95 mm) was significantly larger than those of anteroposterior (1.73±1.31 mm) and lateral directions (0.45±0.37 mm), respectively (p< 0.05). Incidences of over 3 mm and 5 mm in setup difference among the

  14. Prescription dose and fractionation predict improved survival after stereotactic radiotherapy for brainstem metastases

    Directory of Open Access Journals (Sweden)

    Leeman Jonathan E

    2012-07-01

    Full Text Available Abstract Background Brainstem metastases represent an uncommon clinical presentation that is associated with a poor prognosis. Treatment options are limited given the unacceptable risks associated with surgical resection in this location. However, without local control, symptoms including progressive cranial nerve dysfunction are frequently observed. The objective of this study was to determine the outcomes associated with linear accelerator-based stereotactic radiotherapy or radiosurgery (SRT/SRS of brainstem metastases. Methods We retrospectively reviewed 38 tumors in 36 patients treated with SRT/SRS between February 2003 and December 2011. Treatment was delivered with the Cyberknife™ or Trilogy™ radiosurgical systems. The median age of patients was 62 (range: 28–89. Primary pathologies included 14 lung, 7 breast, 4 colon and 11 others. Sixteen patients (44% had received whole brain radiation therapy (WBRT prior to SRT/SRS; ten had received prior SRT/SRS at a different site (28%. The median tumor volume was 0.94 cm3 (range: 0.01-4.2 with a median prescription dose of 17 Gy (range: 12–24 delivered in 1–5 fractions. Results Median follow-up for the cohort was 3.2 months (range: 0.4-20.6. Nineteen patients (52% had an MRI follow-up available for review. Of these, one patient experienced local failure corresponding to an actuarial 6-month local control of 93%. Fifteen of the patients with available follow-up imaging (79% experienced intracranial failure outside of the treatment volume. The median time to distant intracranial failure was 2.1 months. Six of the 15 patients with distant intracranial failure (40% had received previous WBRT. The actuarial overall survival rates at 6- and 12-months were 27% and 8%, respectively. Predictors of survival included Graded Prognostic Assessment (GPA score, greater number of treatment fractions, and higher prescription dose. Three patients experienced acute treatment-related toxicity consisting of

  15. Stereotactic radiotherapy for non-small cell lung cancer: From concept to clinical reality. 2011 update

    International Nuclear Information System (INIS)

    Girard, N.; Mornex, F.

    2011-01-01

    Only 60% of patients with early-stage non-small cell lung cancer (NSCLC), a priori bearing a favorable prognosis, undergo radical resection because of the very frequent co-morbidities occurring in smokers, precluding surgery to be safely performed. Stereotactic radiotherapy consists of the use of multiple radiation micro-beams, allowing high doses of radiation to be delivered to the tumour (ranging from 7.5 to 20 Gy per fraction) in a small number of fractions (one to eight on average). Several studies with long-term follow-up are now available, showing the effectiveness of stereotactic radiotherapy to control stage I/II non-small cell lung cancer in medically inoperable patients. Local control rates are consistently reported to be above 95% with a median survival of 34 to 45 months. Because of these excellent results, stereotactic radiation therapy is now being evaluated in operable patients in several randomized trials with a surgical arm. Ultimately, the efficacy of stereotactic radiotherapy in early-stage tumours leads to hypothesize that it may represent an opportunity for locally-advanced tumors. The specific toxicities of stereotactic radiotherapy mostly correspond to radiation-induced chest wall side effects, especially for peripheral tumours. The use of adapted fractionation schemes has made feasible the use of stereotactic radiotherapy to treat proximal tumours. Overall, from a technical concept to the availability of specific treatment devices and the publication of clinical results, stereotactic radiotherapy represents a model of implementation in thoracic oncology. (authors)

  16. Extracranial doses during stereotactic radiosurgery and fractionated stereotactic radiotherapy measured with thermoluminescent dosimeter in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I.H.; Lim, D.H.; Kim, S.; Hong, S.; Kim, B.K.; Kang, W-S.; Wu, H.G.; Ha, S.W.; Park, C.I. [Seoul National University College of Medicine, Department of Therapeutic Radiology (Korea)

    2000-05-01

    Recently the usage of 3-dimensional non-coplanar radiotherapy technique is increasing. We measured the extracranial dose and its distribution g the above medical procedures to estimate effect of exit doses of stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) of the intracranial target lesions using a linac system developed in our hospital. Among over hundred patients who were treated with SRS or FSRT from 1995 to 1998, radiation dosimetry data of 15 cases with SRS and 20 cases with FSRT were analyzed. All patients were adults. Of SRS cases, 11 were male and 4 were female. Vascular malformation cases were 9, benign tumors were 3, and malignant tumors were 3. Of FSRT cases, males were 12 and females were 8. Primary malignant brain tumors were 5, benign tumors were 6, and metastatic brain tumors were 10. Doses were measured with lithium fluoride TLD chips (7.5% Li-6 and 92.5% Li-7; TLD-100, Harshaw/Filtrol, USA). The chips were attached patient's skin at the various extracranial locations during SRS or FSRT. For SRS, 14-25 Gy were delivered with 1-2 isocenters using 12-38 mm circular tertiary collimators with reference to 50-80% isodose line conforming at the periphery of the target lesions. For FSRT, 5-28 fractions were used to deliver 9-56 Gy to periphery with dose maximum of 10-66 Gy. Both procedures used 6 MV X-ray generated from Clinac-18 (Varian, USA). For SRS procedures, extracranial surface doses (relative doses) were 8.07{+-}4.27 Gy (0.31{+-}0.16% Mean{+-}S.D.) at the upper eyelids, 6.13{+-}4.32 Gy (0.24{+-}0.16%) at the submental jaw, 7.80{+-}5.44 Gy (0.33{+-}0.26%) at thyroid, 1.78{+-}0.64 Gy (0.07{+-}0.02%) at breast, 0.75{+-}0.38 Gy (0.03{+-}0.02%) at umbilicus, 0.40{+-}0.07 Gy (0.02{+-}0.01%) at perineum, and 0.46{+-}0.39 Gy (0.02{+-}0.01%) at scrotum. Thus the farther the distance from the brain, the less the dose to the location. In overall the doses were less than 0.3% and thus less detrimental. For FSRT procedures

  17. The role of accelerated hyperfractionated radiotherapy in the treatment of inoperable non-small cell lung cancer: a controlled clinical trial

    International Nuclear Information System (INIS)

    Reinfuss, M.; Kowalska, T.; Glinski, C.

    2000-01-01

    Radiotherapy remains the basic form of treatment in cases of non-small cell lung cancer (NSCLC) but there still exist controversies concerning optimal radiotherapy regimen and in particular, the total dose and fractionation schedules. To prove whether the question: if using an unconventional dose fractionation regimen (accelerated hyperfractionation) could improve the results of palliative teleradiotherapy patients with NSCLC. Between 1997 and 2000 in the Cancer Centre in Cracow (COOK) a controlled clinical trial was conducted in a group of 150 patients with locally advanced (III Deg) inoperable and unsuitable for radical radiotherapy NSCLC, with no major symptoms of the disease. In 76 patients conventionally fractionated radiotherapy was performed - 50 Gy in 25 fractions during 5 weeks (CF). 74 patients were irradiated twice a day (AHF); the dose per fraction was 1.25 Gy and the minimum interval between fractions - 6 hours. The total dose was 50 Gy in 40 fractions during 26 days. The probability of 12 months survival was 47.4% in the CF arm and 45.9% in the AHF arm; the probability of 24 months survival was 16.2% and 15.8%, respectively. In all 76 patients in CF arm the treatment was carried out in prescribed time without breaks. Out of 74 patients in the A HF group 8 (10,8%) did not complete the treatment and 2 of then died in 3rd and 4th week of treatment. The use of accelerated hyperfractionation does not improve the results of palliative teleradiotherapy in patients with locally advanced NSCLC without severe symptoms related to intrathoracic tumor. The treatment of choice in this group of patients os conventionally fractionated radiotherapy with a total dose of 50 Gy in 25 fractions in 5 week of treatment. (author)

  18. Multi-institutional phase I study of low-dose ultra-fractionated radiotherapy as a chemosensitizer for gemcitabine and erlotinib in patients with locally advanced or limited metastatic pancreatic cancer

    International Nuclear Information System (INIS)

    Konski, Andre; Meyer, Joshua E.; Joiner, Michael; Hall, Michael J.; Philip, Philip; Shields, Anthony; McSpadden, Erin; Choi, Minsig; Adaire, Beth; Duncan, Gail; Meropol, Neal J.; Cescon, Terrence P.; Cohen, Steven J.

    2014-01-01

    Purpose: Gemcitabine (G) has been shown to sensitize pancreatic cancer to radiotherapy but requires lower doses of G and thus delays aggressive systemic treatment, potentially leading to distant failure. We initiated a phase I trial combining ultra-fractionated low-dose radiotherapy with full dose G and erlotinib in the treatment of patients with advanced pancreatic cancer. Methods: Patients with locally advanced or metastatic pancreatic cancer confined to the abdomen and an ECOG performance status (PS) of 0–1 who had received 0–1 prior regimens (without G or E) and no prior radiotherapy were eligible. Patients were treated in 21 day cycles with G IV days 1 and 8, E once PO QD, and twice daily RT fractions separated by at least 4 h on days 1, 2, 8, and 9. Whole abdominal RT fields were used. Primary endpoint was to define dose limiting toxicity (DLT) and the maximum tolerated dose (MTD). Results: 27 patients (median age 64 years and 15 male) were enrolled between 11/24/08 and 4/12/12. 1 patient withdrew consent prior to receiving any protocol therapy. 17 patients had a PS of 1. The majority of patients were stage IV. One DLT was noted out of 7 patients at dose level (DL) 1. Subsequently no DLTs were noted in 3 patients each enrolled at DL2-4 or 11 patients in the expansion cohort. The majority of grade 3 toxicities were hematologic with 1 grade 5 bowel perforation in dose level 1 in cycle 4. Best response in 24 evaluable patients: PR (8), stable (15), PD 1. Median survival for the entire group was 9.1 months. Conclusion: This phase I study combining low-dose ultra-fractionated RT as a sensitizer to full dose G plus E was well tolerated with encouraging efficacy. This represents a novel strategy worthy of further investigation in advanced pancreatic cancer patients

  19. Arsenic partitioning among particle-size fractions of mine wastes and stream sediments from cinnabar mining districts.

    Science.gov (United States)

    Silva, Veronica; Loredo, Jorge; Fernández-Martínez, Rodolfo; Larios, Raquel; Ordóñez, Almudena; Gómez, Belén; Rucandio, Isabel

    2014-10-01

    Tailings from abandoned mercury mines represent an important pollution source by metals and metalloids. Mercury mining in Asturias (north-western Spain) has been carried out since Roman times until the 1970s. Specific and non-specific arsenic minerals are present in the paragenesis of the Hg ore deposit. As a result of intensive mining operations, waste materials contain high concentrations of As, which can be geochemically dispersed throughout surrounding areas. Arsenic accumulation, mobility and availability in soils and sediments are strongly affected by the association of As with solid phases and granular size composition. The objective of this study was to examine phase associations of As in the fine grain size subsamples of mine wastes (La Soterraña mine site) and stream sediments heavily affected by acid mine drainage (Los Rueldos mine site). An arsenic-selective sequential procedure, which categorizes As content into seven phase associations, was applied. In spite of a higher As accumulation in the finest particle-size subsamples, As fractionation did not seem to depend on grain size since similar distribution profiles were obtained for the studied granulometric fractions. The presence of As was relatively low in the most mobile forms in both sites. As was predominantly linked to short-range ordered Fe oxyhydroxides, coprecipitated with Fe and partially with Al oxyhydroxides and associated with structural material in mine waste samples. As incorporated into short-range ordered Fe oxyhydroxides was the predominant fraction at sediment samples, representing more than 80% of total As.

  20. Definitive Radiotherapy of Non-Small Cell Lung Cancer

    International Nuclear Information System (INIS)

    Lee, Jong Young; Park, Kyung Ran

    1995-01-01

    Purpose : The effect of dose escalation of up to 6500 cGy on local control and survival was investigated in locally advanced non-small cell lung cancer. Materials and Methods : Ninety eight patients with biopsy-proven unresectable non-small cell lung cancer without distant metastases or medically inoperable patients with lower-stage were treated with definitive radiotherapy alone. Group A were treated by thoracic irradiation, 6000 cGy or less in total tumor dose with daily fractions of 180 to 200 cGy: and group B was treated with 6500 cGy of same daily fractions. Results : The actuarial overall survival rate for the entire group was 54% at 1 year, 26.6% at 2 years and 16.4% at 3 years with a median survival time of 13 months. Statistically significant prognostic factors that affect survival rate were stage and N-stage. However, no improvement in local control and survival has been seen with higher dose radiotherapy(group B). Conclusion : Dose escalation of up to 6500 cGy was no effect on local control and survival rate. To increase the survival rate of non-small cell lung cancer hyperfractionated radiotherapy or concurrent chemoradiotherapy should be considered

  1. Quantification of fat fraction in lumbar vertebrae: correlation with age and implications for bone marrow dosimetry in molecular radiotherapy

    Science.gov (United States)

    Salas-Ramirez, Maikol; Tran-Gia, Johannes; Kesenheimer, Christian; Weng, Andreas Max; Kosmala, Aleksander; Heidemeier, Anke; Köstler, Herbert; Lassmann, Michael

    2018-01-01

    Absorbed dose to active bone marrow is a predictor of hematological toxicity in molecular radiotherapy. Due to the complex composition of bone marrow tissue, the necessity to improve the personalized dosimetry has led to the application of non-conventional imaging methods in nuclear medicine. The aim of this study is to apply magnetic resonance imaging (MRI) for quantification of the fat fraction in lumbar vertebrae and to analyze its implications for bone marrow dosimetry. First, a highly accelerated two-point Dixon MRI sequence for fat-water separation was validated in a 3T system against the magnetic resonance spectroscopy (MRS) gold standard. The validation was performed in a fat-water phantom composed of 11 vials with different fat fractions between 0% and 100%, and subsequently repeated in the lumbar vertebrae of three healthy volunteers. Finally, a retrospective study was performed by analyzing the fat fraction in five lumbar vertebrae of 44 patients scanned with the two-point Dixon sequence. The two-point Dixon phantom acquisition showed a good agreement (maximum difference  =  2.9%) between the nominal fat fraction and MRS. In the volunteers, a statistical analysis showed a non-significant difference (p  =  0.19) between MRI and MRS. In the patients, gender-specific linear fits for female and male data indicated that the age-dependent marrow conversion (red  →  yellow marrow) is slower in males (0.3% per year) than in females (0.5% per year). Lastly, the fat fraction values showed a considerable variability in patients of similar ages and the same gender. Two-point Dixon MRI enables a non-invasive and spatially resolved quantification of the fat fraction in bone marrow. Our study provides important evidence on the differences in marrow conversion between females and males. In addition, differences were observed in the cellularity values of the International Commission on Radiological Protection (ICRP) reference man (0.7) and the

  2. Concomitant chemo-radiotherapy for locally advanced bronchial cancer: impact of radiotherapy quality on global survival: results of a trial by the Thoracic Cancerology French-speaking Inter-group (IFCT) and Pneumo-Cancerology French Group (GFPC) 02.01

    International Nuclear Information System (INIS)

    Martel-Lafay, I.; Montella, A.; Pommier, P.; Clavere, P.; Labat, J.P.; Benchalal, M.; Teissier, E.; Talabard, J.N.; Fournel, P.; D'Hombres, A.

    2010-01-01

    The author report the assessment of the influence of radiotherapy quality and of its consequences on the future of 113 patients during a phase-II randomized trial of concomitant chemo-radiotherapy of bronchial cancers without stage-II non-resectable small cells. The patients have been submitted to a conformational radiotherapy and a concomitant induction of consolidation chemotherapy. Ten items are analysed: immobilisation, dose per fraction, total dose, ganglion radiotherapy, number of beams, images before and after radiotherapy, radiotherapy duration, duration without radiotherapy, dose-lung volume histogram. The study notably shows the deleterious effects of an interruption of the concomitant chemotherapy on the global survival. Short communication

  3. A case of gastric cancer successfully treated with hyperthermo-chemo-radiotherapy

    International Nuclear Information System (INIS)

    Yonemura, Yutaka; Hashimoto, Tetsuo; Miyata, Ryuwa

    1985-01-01

    A 56-year-old woman was diagnosed as having gastric cancer with lymph node metastasis and invasion to the pancreas head and was admitted to our hospital in September, 1984. She was treated with hyperthermo-chemo-radiotherapy, using radiofrequency-induced hyperthermia (8 MHz) with a daily dose of fractionations at 42-43 0 C for 60 minutes, 5 fractions per week of irradiation at 180 cGy and systemic chemotherapy. After the total doses of hyperthermia and radiation had reached 11.8 hours and 2500 cGy, the primary tumor and lymph node metastasis measured by X-ray examination were reduced in size. On October 8 th, laparotomy was done, and total gastrectomy combined with total pancreatectomy, left hepatic lobectomy and right hemicolectomy was performed. Histologically, almost all of the cancer cells in the primary tumor and lymph node metastasis had disappeared. These results show that this multimodal therapy is effective for local control of gastric cancer, when used preoperatively. (author)

  4. Changes in carbon stability and microbial activity in size fractions of micro-aggregates in a rice soil chronosequence under long term rice cultivation

    Science.gov (United States)

    Pan, Genxing; Liu, Yalong; Wang, Ping; Li, Lianqinfg; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Bian, Rongjun; Ding, Yuanjun; Ma, Chong

    2016-04-01

    Recent studies have shown soil carbon sequestration through physical protection of relative labile carbon intra micro-aggregates with formation of large sized macro-aggregates under good management of soil and agricultural systems. While carbon stabilization had been increasingly concerned as ecosystem properties, the mechanisms underspin bioactivity of soil carbon with increased carbon stability has been still poorly understood. In this study, topsoil samples were collected from rice soils derived from salt marsh under different length of rice cultivation up to 700 years from eastern China. Particle size fractions (PSF) of soil aggregates were separated using a low energy dispersion protocol. Carbon fractions in the PSFs were analyzed either with FTIR spectroscopy. Soil microbial community of bacterial, fungal and archaeal were analyzed with molecular fingerprinting using specific gene primers. Soil respiration and carbon gain from amended maize as well as enzyme activities were measured using lab incubation protocols. While the PSFs were dominated by the fine sand (200-20μm) and silt fraction (20-2μm), the mass proportion both of sand (2000-200μm) and clay (soil aggregates (also referred to aggregate stability). Soil organic carbon was found most enriched in coarse sand fraction (40-60g/kg), followed by the clay fraction (20-24.5g/kg), but depleted in the silt fraction (~10g/kg). Phenolic and aromatic carbon as recalcitrant pool were high (33-40% of total SOC) in both coarse sand and clay fractions than in both fine sand and silt fractions (20-29% of total SOC). However, the ratio of LOC/total SOC showed a weak decreasing trend with decreasing size of the aggregate fractions. Total gene content in the size fractions followed a similar trend to that of SOC. Bacterial and archaeal gene abundance was concentrated in both sand and clay fractions but that of fungi in sand fraction, and sharply decreased with the decreasing size of aggregate fraction. Gene abundance

  5. Lung tumor motion change during stereotactic body radiotherapy (SBRT): an evaluation using MRI

    Science.gov (United States)

    Olivier, Kenneth R.; Li, Jonathan G.; Liu, Chihray; Newlin, Heather E.; Schmalfuss, Ilona; Kyogoku, Shinsuke; Dempsey, James F.

    2014-01-01

    The purpose of this study is to investigate changes in lung tumor internal target volume during stereotactic body radiotherapy treatment (SBRT) using magnetic resonance imaging (MRI). Ten lung cancer patients (13 tumors) undergoing SBRT (48 Gy over four consecutive days) were evaluated. Each patient underwent three lung MRI evaluations: before SBRT (MRI‐1), after fraction 3 of SBRT (MRI‐3), and three months after completion of SBRT (MRI‐3m). Each MRI consisted of T1‐weighted images in axial plane through the entire lung. A cone‐beam CT (CBCT) was taken before each fraction. On MRI and CBCT taken before fractions 1 and 3, gross tumor volume (GTV) was contoured and differences between the two volumes were compared. Median tumor size on CBCT before fractions 1 (CBCT‐1) and 3 (CBCT‐3) was 8.68 and 11.10 cm3, respectively. In 12 tumors, the GTV was larger on CBCT‐3 compared to CBCT‐1 (median enlargement, 1.56 cm3). Median tumor size on MRI‐1, MRI‐3, and MRI‐3m was 7.91, 11.60, and 3.33 cm3, respectively. In all patients, the GTV was larger on MRI‐3 compared to MRI‐1 (median enlargement, 1.54 cm3). In all patients, GTV was smaller on MRI‐3m compared to MRI‐1 (median shrinkage, 5.44 cm3). On CBCT and MRI, all patients showed enlargement of the GTV during the treatment week of SBRT, except for one patient who showed minimal shrinkage (0.86 cm3). Changes in tumor volume are unpredictable; therefore, motion and breathing must be taken into account during treatment planning, and image‐guided methods should be used, when treating with large fraction sizes. PACS number: 87.53.Ly PMID:24892328

  6. Ototoxicity after radiotherapy for head and neck tumors

    International Nuclear Information System (INIS)

    Bhandare, Niranjan; Antonelli, Patrick J.; Morris, Christopher G.; Malayapa, Robert S.; Mendenhall, William M.

    2007-01-01

    Purpose: To investigate the incidence of radiation-induced ototoxicity according to the total dose delivered to specific parts of the auditory system, fractionation, and chemotherapy. Methods and Materials: Records of 325 patients treated for primary extracranial head and neck tumors with curative intent who received radiotherapy between 1964 and 2000 (median follow-up, 5.4 years) were retrospectively reviewed. Reconstructions of the treatment plans were generated to estimate the doses received by components of the auditory system. Results: Radiotherapy-induced morbidity developed in 41.8% of patients (external ear, 33.2%; middle ear, 28.6%; and inner ear, 26.8%). Univariate/multivariate analyses indicate that total dose received by parts of the auditory system seem to be significant, though fractionation and chemoradiation may contribute to the incidence of ototoxicities. Sensorineural hearing loss (SNHL) was observed in 49 patients (15.1%). Univariate and multivariate analyses indicated that age (p = 0.0177 and p = 0.005) and dose to cochlea (p 0.0001) above doses of 60.5 Gy compared to 3% at doses below 60.5 Gy. For patients treated with adjuvant chemotherapy, clinically overt SNHL increased to 30% compared to 18% in the no-chemotherapy group at 10 years (p = 0.0281). Conclusion: Radiotherapy toxicity was observed in all parts of the auditory system with median doses for incidence varying between 60 Gy to 66 Gy. Total dose to organ seems to be a significant factor though fractionation and chemo-radiation may contribute to ototoxicities

  7. Hippocampal-Sparing Whole-Brain Radiotherapy: A 'How-To' Technique Using Helical Tomotherapy and Linear Accelerator-Based Intensity-Modulated Radiotherapy

    International Nuclear Information System (INIS)

    Gondi, Vinai; Tolakanahalli, Ranjini; Mehta, Minesh P.; Tewatia, Dinesh; Rowley, Howard; Kuo, John S.; Khuntia, Deepak; Tome, Wolfgang A.

    2010-01-01

    Purpose: Sparing the hippocampus during cranial irradiation poses important technical challenges with respect to contouring and treatment planning. Herein we report our preliminary experience with whole-brain radiotherapy using hippocampal sparing for patients with brain metastases. Methods and Materials: Five anonymous patients previously treated with whole-brain radiotherapy with hippocampal sparing were reviewed. The hippocampus was contoured, and hippocampal avoidance regions were created using a 5-mm volumetric expansion around the hippocampus. Helical tomotherapy and linear accelerator (LINAC)-based intensity-modulated radiotherapy (IMRT) treatment plans were generated for a prescription dose of 30 Gy in 10 fractions. Results: On average, the hippocampal avoidance volume was 3.3 cm 3 , occupying 2.1% of the whole-brain planned target volume. Helical tomotherapy spared the hippocampus, with a median dose of 5.5 Gy and maximum dose of 12.8 Gy. LINAC-based IMRT spared the hippocampus, with a median dose of 7.8 Gy and maximum dose of 15.3 Gy. On a per-fraction basis, mean dose to the hippocampus (normalized to 2-Gy fractions) was reduced by 87% to 0.49 Gy 2 using helical tomotherapy and by 81% to 0.73 Gy 2 using LINAC-based IMRT. Target coverage and homogeneity was acceptable with both IMRT modalities, with differences largely attributed to more rapid dose fall-off with helical tomotherapy. Conclusion: Modern IMRT techniques allow for sparing of the hippocampus with acceptable target coverage and homogeneity. Based on compelling preclinical evidence, a Phase II cooperative group trial has been developed to test the postulated neurocognitive benefit.

  8. Surface-enhanced Raman spectroscopy of chernozem humic acid and their fractions obtained by coupled size exclusion chromatography-polyacrylamide gel electrophoresis (SEC-PAGE).

    Science.gov (United States)

    Sanchez-Cortes, S; Corrado, G; Trubetskaya, O E; Trubetskoj, O A; Hermosin, B; Saiz-Jimenez, C

    2006-01-01

    A humic acid extracted from a chernozem soil was fractionated combining size exclusion chromatography and polyacrylamide electrophoresis (SEC-PAGE). Three fractions named A, B, and C+D, with different electrophoretic mobilities and molecular sizes (MS), were obtained and subsequently characterized by thermochemolysis and surface-enhanced Raman spectroscopy (SERS). The data confirmed that fraction A, with the higher MS, was more aliphatic than fractions B and C+D and, in turn, fractions with lower MS (B and C+D) denoted an enrichment in lignin residues. These structural features explain conformational changes when varying the pH in the humic fraction A and indicated that combination of the two techniques is a good approach for characterizing humic substances.

  9. Radiotherapy for carcinoma of the larynx

    International Nuclear Information System (INIS)

    Terhaard, C.H.J.

    1991-01-01

    Data of patients treated for laryngeal cancer with radiotherapy are analyzed by uni- and multivariate methods. Patients are subdivided into the various T-categories, obtaining more homogeneous groups of laryngeal cancer. Prognostic factors are defined for survival, local and regional control after radiotherapy, and for ultimate locoregional control after salvage surgery (partial or total laryngectomy and/or neck dissection). An attempt is made to set up a refined treatment recommendation, based on these prognostic factors, and to define an optimal fractionation schedule for advanced laryngeal cancer. Future prospects to improve the therapeutic ratio on advanced laryngeal cancer are discussed. (H.W.). 360 refs.; 28 figs.; 35 tabs

  10. Hypofractionated radiotherapy for invasive bladder cancer

    International Nuclear Information System (INIS)

    Scholten, Astrid N.; Leer, Jan-Willem H.; Collins, C. David; Wondergem, Jan; Hermans, Jo; Timothy, Adrian

    1997-01-01

    Background and purpose: The policy of the Radiotherapy Department of St. Thomas' Hospital in London for patients with invasive bladder cancer, used to be treatment with hypofractionated radiotherapy. The advantages of this fractionation scheme included reduction of the number of treatment sessions and better use of limited resources. Our results after hypofractionation were compared to series with more conventional radiotherapy. Material and methods: Between 1975 and 1985, 123 patients with a T2-T3 transitional cell carcinoma of the bladder were treated by a radical course of hypofractionated radiotherapy. Local control, survival and morbidity rates were analysed retrospectively. Results: The actuarial local control rates at 5 and 10 years were 31 and 29%, respectively. The actuarial cancer-specific 5- and 10-year survival rates were 48 and 39%, respectively. Acute side effects were observed in 87% of patients. The actuarial overall and severe late complication rates at 5 years were 33 and 9%, respectively. The local control, survival and early side effect rates we found, were in the same range as those reported in literature. Late radiation side effects however, were more common after hypofractionated radiotherapy compared to conventional radiotherapy schedules. Conclusions: We conclude that the potential advantage of a reduced number of treatment sessions may be lost in the long term, because of the higher incidence of late morbidity after hypofractionated radiotherapy. Hypofractionation however, remains a valuable technique for palliation and deserves further investigation for radical treatment where access to equipment is difficult or resources are limited

  11. DEGRO practical guidelines for the radiotherapy of non-malignant disorders. Pt. IV. Symptomatic functional disorders

    Energy Technology Data Exchange (ETDEWEB)

    Reinartz, Gabriele; Eich, Hans Theodor [University Hospital Muenster, Department of Radiation Oncology, Muenster (Germany); Pohl, Fabian [University Hospital Regensburg, Department of Radiotherapy, Regensburg (Germany); Collaboration: German Cooperative Group on Radiotherapy for Benign Diseases (GCG-BD)

    2015-04-01

    To summarize the updated DEGRO consensus S2e guideline recommendations for the treatment of benign symptomatic functional disorders with low-dose radiotherapy. This overview reports on the role of low-dose radiotherapy in the treatment of functional disorders in cases of heterotopic ossification (HO) and Graves orbitopathy (GO). The most relevant aspects of the DEGRO S2e Consensus Guideline ''Radiation Therapy of Benign Diseases 2014'' regarding diagnostics, treatment decision, dose prescription, as well as performance of radiotherapy and results are summarized. For both indications (HO, GO), retrospective and some prospective analyses have shown remarkable effects in terms of symptom relief. Nevertheless, the level of evidence (LoE) and the grade of recommendation (GR) vary: LoE 1-2 and GR A-B (HO), LoE 2 and GR B (GO). Low-dose radiotherapy for benign symptomatic functional disorders has proven to be effective, according to different authors, for 25-100 % of the patients studied and therefore it may be a reasonable prophylactic and therapeutic option if noninvasive or invasive methods have been used without persistent success. For HO, a single-fraction dose of 7-8 Gy or fractionated radiation with five fractions of 3.5 Gy is recommended. For GO, single-fraction doses of 0.3-2.0 Gy, and total doses of 2.4-20 Gy/series, applied in one daily fraction are recommended. (orig.) [German] Zusammenfassung der Empfehlungen der DEGRO-S2e-Leitlinie zur Niedrigdosis-Radiotherapie von gutartigen symptomatischen funktionellen Erkrankungen. Die vorliegende Leitlinie berichtet ueber die Bedeutung der Niedrigdosis-Radiotherapie in der Behandlung von funktionellen Erkrankungen, in diesem Fall von heterotoper Ossifikation (HO) und endokriner Orbitopathie (EO). Es werden die wichtigsten Aspekte der aktuellen DEGRO-S2e-Konsensusleitlinie ''Strahlentherapie gutartiger Erkrankungen 2014'' bezueglich Diagnostik, Therapieentscheidungen

  12. Stereotactic radiotherapy for non-small cell lung cancer: From concept to clinical reality. 2011 update; Radiotherapie stereotaxique des cancers broncho-pulmonaires non a petites cellules: d'un concept a une realite clinique. Actualites en 2011

    Energy Technology Data Exchange (ETDEWEB)

    Girard, N. [Service de pneumologie, hopital Louis-Pradel, hospices civils de Lyon, 28, avenue du Doyen-Jean-Lepine, 69500 Bron (France); UMR 754, universite Claude-Bernard Lyon 1, 43, boulevard du 11-Novembre-1918, 69622 Villeurbanne cedex (France); Mornex, F. [Departement de radiotherapie oncologie, centre hospitalier Lyon-Sud, 165, chemin du Grand-Revoyet, 69495 Pierre-Benite cedex (France); EA 37-38, universite Claude-Bernard Lyon 1, 43, boulevard du 11-Novembre-1918, 69622 Villeurbanne cedex (France)

    2011-10-15

    Only 60% of patients with early-stage non-small cell lung cancer (NSCLC), a priori bearing a favorable prognosis, undergo radical resection because of the very frequent co-morbidities occurring in smokers, precluding surgery to be safely performed. Stereotactic radiotherapy consists of the use of multiple radiation micro-beams, allowing high doses of radiation to be delivered to the tumour (ranging from 7.5 to 20 Gy per fraction) in a small number of fractions (one to eight on average). Several studies with long-term follow-up are now available, showing the effectiveness of stereotactic radiotherapy to control stage I/II non-small cell lung cancer in medically inoperable patients. Local control rates are consistently reported to be above 95% with a median survival of 34 to 45 months. Because of these excellent results, stereotactic radiation therapy is now being evaluated in operable patients in several randomized trials with a surgical arm. Ultimately, the efficacy of stereotactic radiotherapy in early-stage tumours leads to hypothesize that it may represent an opportunity for locally-advanced tumors. The specific toxicities of stereotactic radiotherapy mostly correspond to radiation-induced chest wall side effects, especially for peripheral tumours. The use of adapted fractionation schemes has made feasible the use of stereotactic radiotherapy to treat proximal tumours. Overall, from a technical concept to the availability of specific treatment devices and the publication of clinical results, stereotactic radiotherapy represents a model of implementation in thoracic oncology. (authors)

  13. [The need for a paradigm shift in radiotherapy].

    Science.gov (United States)

    Mayer, Árpád; Katona, Csilla; Farkas, Róbert; Póti, Zsuzsa

    2015-11-01

    The status and indications of radiotherapy have significantly changed in the past decade because novel techniques, radiobiological research and major advances in informatics have made better local control possible. Using supplemented marking of the target volume with computer tomography based other image-making methods adapted made it possible to define the tumor and intact surrounding tissues more precisely. With novel radiotherapy techniques the dosage of the homogenity and the covering in the target volume can be raised optimally, especially with intensity modulated arc radiotherapy (volumetric modulated arc therapy) without causing radiation injury or damage to intact surrounding tissues. Furthermore, with novel techniques and target volume marking, new indications have appeared in clinical practice and besides stereotactic radiotherapy for intracranial metastases, the extracranial so-called oligometastic conditions can be maintained close to a curative state (or in remission) for many years. Among these, perhaps the most striking is the stereotactic radiotherapy treatment of liver, lung and spinal cord metastases in one or more fractions, for which the indispensable condition is the image or respiratory guided technique.

  14. Adaptive-Predictive Organ Localization Using Cone-Beam Computed Tomography for Improved Accuracy in External Beam Radiotherapy for Bladder Cancer

    International Nuclear Information System (INIS)

    Lalondrelle, Susan; Huddart, Robert; Warren-Oseni, Karole; Hansen, Vibeke Nordmark; McNair, Helen; Thomas, Karen; Dearnaley, David; Horwich, Alan; Khoo, Vincent

    2011-01-01

    Purpose: To examine patterns of bladder wall motion during high-dose hypofractionated bladder radiotherapy and to validate a novel adaptive planning method, A-POLO, to prevent subsequent geographic miss. Methods and Materials: Patterns of individual bladder filling were obtained with repeat computed tomography planning scans at 0, 15, and 30 minutes after voiding. A series of patient-specific plans corresponding to these time-displacement points was created. Pretreatment cone-beam computed tomography was performed before each fraction and assessed retrospectively for adaptive intervention. In fractions that would have required intervention, the most appropriate plan was chosen from the patient's 'library,' and the resulting target coverage was reassessed with repeat cone-beam computed tomography. Results: A large variation in patterns of bladder filling and interfraction displacement was seen. During radiotherapy, predominant translations occurred cranially (maximum 2.5 cm) and anteriorly (maximum 1.75 cm). No apparent explanation was found for this variation using pretreatment patient factors. A need for adaptive planning was demonstrated by 51% of fractions, and 73% of fractions would have been delivered correctly using A-POLO. The adaptive strategy improved target coverage and was able to account for intrafraction motion also. Conclusions: Bladder volume variation will result in geographic miss in a high proportion of delivered bladder radiotherapy treatments. The A-POLO strategy can be used to correct for this and can be implemented from the first fraction of radiotherapy; thus, it is particularly suited to hypofractionated bladder radiotherapy regimens.

  15. Radiotherapy in skin cancer - present day aspects

    International Nuclear Information System (INIS)

    Gocheva, L.

    2009-01-01

    Skin carcinomas (SC) are the leading ones in the structure of oncological morbidity in both genders in Bulgaria, as well as in white populations in the world. Regardless of their high frequency, their treatment is successful and mortality due to SC has been reduced by 20 - 30% during the last decades. In Bulgaria SC in 2003 comprise 9.3% of all oncological diseases in men and women. According to their frequency they occupy the second phase after lung cancer in men and breast cancer in women. The treatment of SC is realized applying various therapeutic approaches, distinguished as basic (radical) and alternative ones. The first include surgical treatment and radiotherapy (RT) (definitive or adjuvant) and the alternative ones - curettage and electro-coagulation, cryotherapy, local chemotherapy and immunotherapy, systemic chemotherapy, etc. When defining the therapeutic approach, the method affording the best chances of curing with acceptable cosmetic results should be selected. The present review is aimed at considering the contemporary aspects in RT of SC, including used radiotherapy methods and techniques, volumes, doses, fractionation, and achieved therapeutic effects. The indications for implementing definitive and adjuvant RT are given in detail. The applied radiotherapy methods - external beam RT and brachytherapy, are also discussed. The used planned radiotherapy volumes, doses, fractionation schemes, attained therapeutic effects and possible radiation reactions are considered as well. The curability of SC is high, exceeding 90% after adequate treatment. Regardless of the fact that RT has partially ceded its leading role in SC treatment, it still remains to be one of the basic and successful therapeutic approaches

  16. The relationship between external beam radiotherapy dose and chronic urinary dysfunction - A methodological critique

    International Nuclear Information System (INIS)

    Rosewall, Tara; Catton, Charles; Currie, Geoffrey; Bayley, Andrew; Chung, Peter; Wheat, Janelle; Milosevic, Michael

    2010-01-01

    Purpose: To perform a methodological critique of the literature evaluating the relationship between external beam radiotherapy dose/volume parameters and chronic urinary dysfunction to determine why consistent associations between dose and dysfunction have not been found. Methods and materials: The radiotherapy literature was reviewed using various electronic medical search engines with appropriate keywords and MeSH headings. Inclusion criteria comprised of; English language articles, published between 1999 and June 2009, incorporating megavoltage external beam photons in standard-sized daily fraction. A methodological critique was then performed, evaluating the factors affected in the quantification of radiotherapy dose and chronic urinary dysfunction. Results: Nine of 22 eligible studies successfully identified a clinically and statistically significant relationship between dose and dysfunction. Accurate estimations of external beam radiotherapy dose were compromised by the frequent use of dosimetric variables which are poor surrogates for the dose received by the lower urinary tract tissue and do not incorporate the effect of daily variations in isocentre and bladder position. The precise categorization of chronic urinary dysfunction was obscured by reliance on subjective and aggregated toxicity metrics which vary over time. Conclusions: A high-level evidence-base for the relationship between external beam radiotherapy dose and chronic urinary dysfunction does not currently exist. The quantification of the actual external beam dose delivered to the functionally important tissues using dose accumulation strategies and the use of objective measures of individual manifestations of urinary dysfunction will assist in the identification of robust relationships between dose and urinary dysfunction for application in widespread clinical practice.

  17. Verification of respiratory-gated radiotherapy with new real-time tumour-tracking radiotherapy system using cine EPID images and a log file.

    Science.gov (United States)

    Shiinoki, Takehiro; Hanazawa, Hideki; Yuasa, Yuki; Fujimoto, Koya; Uehara, Takuya; Shibuya, Keiko

    2017-02-21

    A combined system comprising the TrueBeam linear accelerator and a new real-time tumour-tracking radiotherapy system, SyncTraX, was installed at our institution. The objectives of this study are to develop a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine electronic portal image device (EPID) images and a log file and to verify this treatment in clinical cases. Respiratory-gated radiotherapy was performed using TrueBeam and the SyncTraX system. Cine EPID images and a log file were acquired for a phantom and three patients during the course of the treatment. Digitally reconstructed radiographs (DRRs) were created for each treatment beam using a planning CT set. The cine EPID images, log file, and DRRs were analysed using a developed software. For the phantom case, the accuracy of the proposed method was evaluated to verify the respiratory-gated radiotherapy. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker used as an internal surrogate were calculated to evaluate the gating accuracy and set-up uncertainty in the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions. The proposed method achieved high accuracy for the phantom verification. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker were  ⩽3 mm and  ±3 mm in the SI, AP, and LR directions. We proposed a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine EPID images and a log file and showed that this treatment is performed with high accuracy in clinical cases.

  18. Modeling the Risk of Secondary Malignancies after Radiotherapy

    Directory of Open Access Journals (Sweden)

    Uwe Schneider

    2011-11-01

    Full Text Available In developed countries, more than half of all cancer patients receive radiotherapy at some stage in the management of their disease. However, a radiation-induced secondary malignancy can be the price of success if the primary cancer is cured or at least controlled. Therefore, there is increasing concern regarding radiation-related second cancer risks in long-term radiotherapy survivors and a corresponding need to be able to predict cancer risks at high radiation doses. Of particular interest are second cancer risk estimates for new radiation treatment modalities such as intensity modulated radiotherapy, intensity modulated arc-therapy, proton and heavy ion radiotherapy. The long term risks from such modern radiotherapy treatment techniques have not yet been determined and are unlikely to become apparent for many years, due to the long latency time for solid tumor induction. Most information on the dose-response of radiation-induced cancer is derived from data on the A-bomb survivors who were exposed to γ-rays and neutrons. Since, for radiation protection purposes, the dose span of main interest is between zero and one Gy, the analysis of the A-bomb survivors is usually focused on this range. With increasing cure rates, estimates of cancer risk for doses larger than one Gy are becoming more important for radiotherapy patients. Therefore in this review, emphasis was placed on doses relevant for radiotherapy with respect to radiation induced solid cancer. Simple radiation protection models should be used only with extreme care for risk estimates in radiotherapy, since they are developed exclusively for low dose. When applied to scatter radiation, such models can predict only a fraction of observed second malignancies. Better semi-empirical models include the effect of dose fractionation and represent the dose-response relationships more accurately. The involved uncertainties are still huge for most of the organs and tissues. A major reason for

  19. Analysis of late complications after rapid hyperfractionated radiotherapy in advanced head and neck cancers

    International Nuclear Information System (INIS)

    Nguyen, T.D.; Panis, X.; Froissart, D.; Legros, M.; Coninx, P.; Loirette, M.

    1988-01-01

    Late effects were analyzed in a series of 39 patients with a 2-year minimal follow-up who were treated by rapid hyperfractionated radiotherapy. The total dose was 66-72 Gy delivered in two series of 33-36 Gy separated by a 2-4 week rest interval. The number of daily fractions ranged from 8 to 6 and the interval between each fraction was 2 hr. Late complications consisted of cervical fibrosis, mucosal necrosis, bone necrosis, trismus, and laryngeal edema. Seventy percent of patients experienced late complications, and in 54% of cases, these reactions were considered severe, causing death in 13% of patients. No relationship was found between field sizes, dosimetric data and type and frequency of late effects. It is therefore suggested that the interval between two daily sessions in any multifractionated protocol may be of critical importance

  20. Objective assessment of dermatitis following post-operative radiotherapy in patients with breast cancer treated with breast-conserving treatment

    International Nuclear Information System (INIS)

    Yoshida, Ken; Takenaka, Tadashi; Tanaka, Eiichi; Kuriyama, Keiko; Yoshida, Mineo; Yamazaki, Hideya; Nishimura, Tsunehiko; Kotsuma, Tadayuki; Fujita, Yuka; Masuda, Norikazu

    2010-01-01

    To evaluate radiation dermatitis objectively in patients with breast cancer who had undergone post-operative radiotherapy after breast-conserving surgery. Skin color (L * , a * , and b * values) and moisture analyses were performed for both breasts (before, after, 1 month, 6 months, and 1 year after radiotherapy) to examine irradiated and non-irradiated skin divided into four quadrants in 118 patients. These patients underwent breast conservative surgery followed by 50 Gy/25 fractions (median) of radiotherapy with or without boost irradiation (10 Gy/5 fractions). L * , a * , and moisture values were changed by irradiation and maximized at completion or 1 month after radiotherapy. One year after radiotherapy, the skin color had returned to the range observed prior to radiotherapy. However, moisture did not return to previous values even 1 year after treatment. The lateral upper side (quadrant C) showed greater changes than other quadrants in the L * value (darker) at the end of radiotherapy. The Common Toxicity Criteria version 3 scores were found to correlate well with a * and L * values at the completion and 1 month after radiotherapy. Boost radiotherapy intensified reddish and darker color changes at the completion of radiotherapy, while chemotherapy did not intensify the skin reaction caused by radiotherapy. Moisture impairment as a result of irradiation lasts longer than color alterations. Objective assessments are useful for analyzing radiation dermatitis. (orig.)

  1. Radiotherapy results of uterine cervix cancer stape IIB : overall survival, prognostic facters, patterns of failure and late complications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Seog; Choi, Doo Ho [Soonchunhyang Univ. College of Medicine, Asan (Korea, Republic of); Huh, Seung Jae [Samsung Medical Center, Sungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of)

    1998-03-01

    Treatment of choice for uterine cervix cancer stage IIB is radiotherapy. We analyzed survivals, prognostic factors, patterns of failure and complications. This is a retrospective analysis of 167 patients with stage IIB carcinoma of uterine cervix treated with curative external pelvic and high dose rate intracavitary radiotherapy at the Department of Therapeutic Radiology, Soonchunhyang University Hospital from August 1985 to August 1994. All the patients followed up from 3 to 141 months(mean 60 months) and age of patients ranged from 31 to 78 years at presentation(mean : 55 years). Overall complete response rate was 84%. The response rate for squamous cell carcimoma and adenocarcinoma were 86% and 60%, respectively. Overall 5-years survival rate and disease free survival rate was 62 and 59%, respectively. Mass size and treatment response were significant prognostic factors for survival. Pathologic type and parametrial involvement were marginally significants prognostic factors. Local failure was 43 cases, distant metastasis was 14 cases and local failure plus distant metastasis was 3 cases, and most of local failures occurred within 24 months, distant metastasis within 12 months after treatment. Twenty eight(16.8%) patients developed late rectal and urinary complications There were tendency to increasing severity and frequency according to increased fractional dose and total(rectal and bladder) dose. Survival rate was significantly related to tumor size and radiotherapy response. Tumor size should be considered in the clinical staging. To increased survival and local control, clinical trials such as decreasing duration of radiotherapy or addition of chemotherapy is needed. To detect early recurrence, regular follow up after RT is important. Because total rectal and bladder dose affected late complications, meticulous vaginal packing is needed to optimize dose of normal tissues and to decrease late complications.

  2. Radiotherapy problem under fuzzy theoretic approach

    International Nuclear Information System (INIS)

    Ammar, E.E.; Hussein, M.L.

    2003-01-01

    A fuzzy set theoretic approach is used for radiotherapy problem. The problem is faced with two goals: the first is to maximize the fraction of surviving normal cells and the second is to minimize the fraction of surviving tumor cells. The theory of fuzzy sets has been employed to formulate and solve the problem. A linguistic variable approach is used for treating the first goal. The solutions obtained by the modified approach are always efficient and best compromise. A sensitivity analysis of the solutions to the differential weights is given

  3. Thyroid tumours following fractionated irradiation in childhood

    International Nuclear Information System (INIS)

    Vathaire, F. de; Grimaud, E.; Diallo, I.; Shamsaldin, A.

    1997-01-01

    Results of a cohort study designed to evaluate the long term risk of thyroid tumours after fractioned high doses of external beam radiotherapy received by the thyroid are reported. In this cohort study, doses have been estimated for each child. (author)

  4. Short-term bioavailability of carbon in soil organic matter fractions of different particle sizes and densities in grassland ecosystems.

    Science.gov (United States)

    Breulmann, Marc; Masyutenko, Nina Petrovna; Kogut, Boris Maratovich; Schroll, Reiner; Dörfler, Ulrike; Buscot, François; Schulz, Elke

    2014-11-01

    The quality, stability and availability of organic carbon (OC) in soil organic matter (SOM) can vary widely between differently managed ecosystems. Several approaches have been developed for isolating SOM fractions to examine their ecological roles, but links between the bioavailability of the OC of size-density fractions and soil microbial communities have not been previously explored. Thus, in the presented laboratory study we investigated the potential bioavailability of OC and the structure of associated microbial communities in different particle-size and density fractions of SOM. For this we used samples from four grassland ecosystems with contrasting management intensity regimes and two soil types: a Haplic Cambisol and a typical Chernozem. A combined size-density fractionation protocol was applied to separate clay-associated SOM fractions (CF1, <1 μm; CF2, 1-2 μm) from light SOM fractions (LF1, <1.8 g cm(-3); LF2, 1.8-2.0 g cm(-3)). These fractions were used as carbon sources in a respiration experiment to determine their potential bioavailability. Measured CO2-release was used as an index of substrate accessibility and linked to the soil microbial community structure, as determined by phospholipid fatty acids (PLFA) analysis. Several key factors controlling decomposition processes, and thus the potential bioavailability of OC, were identified: management intensity and the plant community composition of the grasslands (both of which affect the chemical composition and turnover of OC) and specific properties of individual SOM fractions. The PLFA patterns highlighted differences in the composition of microbial communities associated with the examined grasslands, and SOM fractions, providing the first broad insights into their active microbial communities. From observed interactions between abiotic and biotic factors affecting the decomposition of SOM fractions we demonstrate that increasing management intensity could enhance the potential bioavailability of

  5. Radiotherapy of Graves' ophthalmopathy. State of the art and review of the literature; Radiotherapie der endokrinen Orbitopathie. State of the Art und Literaturuebersicht

    Energy Technology Data Exchange (ETDEWEB)

    Eich, H.T. [Klinikum der Univ. Koeln (Germany). Klinik und Poliklinik fuer Strahlentherapie; Micke, O. [Franziskus-Hospital Bielefeld (Germany). Klinik fuer Radioonkologie und Strahlentherapie; Seegenschmiedt, M.H. [Alfried-Krupp Krankenhaus Essen (Germany). Klinik fuer Radioonkologie und Strahlentherapie

    2007-07-01

    Graves' ophthalmopathy (GO), the most frequent extrathyroidal manifestation of Graves' disease, is a disorder of autoimmune origin, the pathogenic mechanisms of which are still incompletely understood. Although GO is severe in only 3-5% of affected individuals, quality of life is severely impaired even in patients with mild GO. The role of radiotherapy in the management of GO is discussed controversially. However, recent randomized clinical trials have, with one exception, confirmed that orbital radiotherapy is an effective and safe therapeutic procedure for GO. This article describes the sequences, dosages and fractionation schemes as well as the risks and side effects of the radiotherapy. (orig.)

  6. Simultaneous Integrated Boost Using Intensity-Modulated Radiotherapy Compared With Conventional Radiotherapy in Patients Treated With Concurrent Carboplatin and 5-Fluorouracil for Locally Advanced Oropharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Clavel, Sebastien, E-mail: sebastien.clavel@umontreal.ca [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Nguyen, David H.A.; Fortin, Bernard [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada); Despres, Philippe [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Khaouam, Nader [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada); Donath, David [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Soulieres, Denis [Department of Medical Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Guertin, Louis [Department of Head and Neck Surgery, Centre Hospitalier de l' Universite de Montreal, Montreal, QC (Canada); Nguyen-Tan, Phuc Felix [Department of Radiation Oncology, Hopital Maisonneuve-Rosemont, Montreal, QC (Canada)

    2012-02-01

    Purpose: To compare, in a retrospective study, the toxicity and efficacy of simultaneous integrated boost using intensity-modulated radiotherapy (IMRT) vs. conventional radiotherapy (CRT) in patients treated with concomitant carboplatin and 5-fluorouracil for locally advanced oropharyngeal cancer. Methods and Materials: Between January 2000 and December 2007, 249 patients were treated with definitive chemoradiation. One hundred patients had 70 Gy in 33 fractions using IMRT, and 149 received CRT at 70 Gy in 35 fractions. Overall survival, disease-free survival, and locoregional control were estimated using the Kaplan-Meier method. Results: Median follow-up was 42 months. Three-year actuarial rates for locoregional control, disease-free survival, and overall survival were 95.1% vs. 84.4% (p = 0.005), 85.3% vs. 69.3% (p = 0.001), and 92.1% vs. 75.2% (p < 0.001) for IMRT and CRT, respectively. The benefit of the radiotherapy regimen on outcomes was also observed with a Cox multivariate analysis. Intensity-modulated radiotherapy was associated with less acute dermatitis and less xerostomia at 6, 12, 24, and 36 months. Conclusions: This study suggests that simultaneous integrated boost using IMRT is associated with favorable locoregional control and survival rates with less xerostomia and acute dermatitis than CRT when both are given concurrently with chemotherapy.

  7. Simultaneous Integrated Boost Using Intensity-Modulated Radiotherapy Compared With Conventional Radiotherapy in Patients Treated With Concurrent Carboplatin and 5-Fluorouracil for Locally Advanced Oropharyngeal Carcinoma

    International Nuclear Information System (INIS)

    Clavel, Sébastien; Nguyen, David H.A.; Fortin, Bernard; Després, Philippe; Khaouam, Nader; Donath, David; Soulières, Denis; Guertin, Louis; Nguyen-Tan, Phuc Felix

    2012-01-01

    Purpose: To compare, in a retrospective study, the toxicity and efficacy of simultaneous integrated boost using intensity-modulated radiotherapy (IMRT) vs. conventional radiotherapy (CRT) in patients treated with concomitant carboplatin and 5-fluorouracil for locally advanced oropharyngeal cancer. Methods and Materials: Between January 2000 and December 2007, 249 patients were treated with definitive chemoradiation. One hundred patients had 70 Gy in 33 fractions using IMRT, and 149 received CRT at 70 Gy in 35 fractions. Overall survival, disease-free survival, and locoregional control were estimated using the Kaplan-Meier method. Results: Median follow-up was 42 months. Three-year actuarial rates for locoregional control, disease-free survival, and overall survival were 95.1% vs. 84.4% (p = 0.005), 85.3% vs. 69.3% (p = 0.001), and 92.1% vs. 75.2% (p < 0.001) for IMRT and CRT, respectively. The benefit of the radiotherapy regimen on outcomes was also observed with a Cox multivariate analysis. Intensity-modulated radiotherapy was associated with less acute dermatitis and less xerostomia at 6, 12, 24, and 36 months. Conclusions: This study suggests that simultaneous integrated boost using IMRT is associated with favorable locoregional control and survival rates with less xerostomia and acute dermatitis than CRT when both are given concurrently with chemotherapy.

  8. Hypofractionated stereotactic photon radiotherapy of posteriorly located choroidal melanoma with five fractions at ten Gy – Clinical results after six years of experience

    International Nuclear Information System (INIS)

    Dunavoelgyi, Roman; Zehetmayer, Martin; Gleiss, Andreas; Geitzenauer, Wolfgang; Kircher, Karl; Georg, Dietmar; Schmidt-Erfurth, Ursula; Poetter, Richard; Dieckmann, Karin

    2013-01-01

    Purpose: To evaluate long-term safety and efficacy of hypofractionated stereotactic photon radiotherapy with 5 five fractions at 10 Gy each in patients with centrally located choroidal melanoma. Materials and Methods: Ninety-one patients with centrally located choroidal melanoma were treated stereotactically at a linear accelerator with 6 MV photon beams with 5 fractions at 10 Gy each. Examinations were performed at baseline and every 3 months in the first 2 years, then every 6 months until 5 years and yearly thereafter. Median follow-up was 37.8 months (IQR 19.2–49.9). They included visual acuity assessment, routine ophthalmological examinations with fundoscopy, echography for measurement of tumor dimensions, medical examinations and, if necessary, fluorescein angiography. Results: Initial tumor base diameters, height and volume were 11.20 mm (IQR 9.10–13.70), 9.80 mm (IQR 7.80–11.70), 4.53 mm (IQR 3.33–6.43) and 253.8 mm 3 (IQR 127.5–477.0). Local tumor control and eye retention rates were 97.7% and 86.4% after 5 years, respectively. Eight patients developed metastatic disease and 3 of them died due to metastatic disease during the follow-up period. Median visual acuity decreased from 0.67 initially to 0.05 at the last individual follow-up (p < 0.001). The most common toxicities (any grade) were radiation retinopathy (n = 39), optic neuropathy (n = 32), radiogenic cataract (n = 21), neovascular glaucoma (n = 15) and dry eye syndrome (n = 10). The 5 year probabilities to remain free of these side effects (any grade) were 26.0%, 45.4%, 55.4%, 72.6% and 80.5%, respectively. The most important prognostic factors for toxicities were the largest tumor base diameter, tumor height and tumor distance to the optic disk. Conclusion: Hypofractionated stereotactic photon radiotherapy with a total dose of 50 Gy delivered in 5 fractions is a highly effective treatment option in patients with centrally located choroidal melanoma and has a moderate toxicity profile

  9. Case study thoracic radiotherapy in an elderly patient with pacemaker: The issue of pacing leads

    International Nuclear Information System (INIS)

    Kirova, Youlia M.; Menard, Jean; Chargari, Cyrus; Mazal, Alejandro; Kirov, Krassen

    2012-01-01

    To assess clinical outcome of patients with pacemaker treated with thoracic radiation therapy for T8-T9 paravertebral chloroma. A 92-year-old male patient with chloroma presenting as paravertebral painful and compressive (T8-T9) mass was referred for radiotherapy in the Department of Radiation Oncology, Institut Curie. The patient presented with cardiac dysfunction and a permanent pacemaker that had been implanted prior. The decision of Multidisciplinary Meeting was to deliver 30 Gy in 10 fractions for reducing the symptoms and controlling the tumor growth. The patient received a total dose of 30 Gy in 10 fractions using 4-field conformal radiotherapy with 20-MV photons. The dose to pacemaker was 0.1 Gy but a part of the pacing leads was in the irradiation fields. The patient was treated the first time in the presence of his radiation oncologist and an intensive care unit doctor. Moreover, the function of his pacemaker was monitored during the entire radiotherapy course. No change in pacemaker function was observed during any of the radiotherapy fractions. The radiotherapy was very well tolerated without any side effects. The function of the pacemaker was checked before and after the radiotherapy treatment by the cardiologist and no pacemaker dysfunction was observed. Although updated guidelines are needed with acceptable dose criteria for implantable cardiac devices, it is possible to treat patients with these devices and parts encroaching on the radiation field. This case report shows we were able to safely treat our patient through a multidisciplinary approach, monitoring the patient during each step of the treatment.

  10. Case study thoracic radiotherapy in an elderly patient with pacemaker: The issue of pacing leads

    Energy Technology Data Exchange (ETDEWEB)

    Kirova, Youlia M., E-mail: youlia.kirova@curie.net [Department of Radiation Oncology, Institut Curie, Paris (France); Menard, Jean; Chargari, Cyrus; Mazal, Alejandro [Department of Radiation Oncology, Institut Curie, Paris (France); Kirov, Krassen [Department of Anesthesiology and Reanimation, Institut Curie, Paris (France)

    2012-07-01

    To assess clinical outcome of patients with pacemaker treated with thoracic radiation therapy for T8-T9 paravertebral chloroma. A 92-year-old male patient with chloroma presenting as paravertebral painful and compressive (T8-T9) mass was referred for radiotherapy in the Department of Radiation Oncology, Institut Curie. The patient presented with cardiac dysfunction and a permanent pacemaker that had been implanted prior. The decision of Multidisciplinary Meeting was to deliver 30 Gy in 10 fractions for reducing the symptoms and controlling the tumor growth. The patient received a total dose of 30 Gy in 10 fractions using 4-field conformal radiotherapy with 20-MV photons. The dose to pacemaker was 0.1 Gy but a part of the pacing leads was in the irradiation fields. The patient was treated the first time in the presence of his radiation oncologist and an intensive care unit doctor. Moreover, the function of his pacemaker was monitored during the entire radiotherapy course. No change in pacemaker function was observed during any of the radiotherapy fractions. The radiotherapy was very well tolerated without any side effects. The function of the pacemaker was checked before and after the radiotherapy treatment by the cardiologist and no pacemaker dysfunction was observed. Although updated guidelines are needed with acceptable dose criteria for implantable cardiac devices, it is possible to treat patients with these devices and parts encroaching on the radiation field. This case report shows we were able to safely treat our patient through a multidisciplinary approach, monitoring the patient during each step of the treatment.

  11. Treatment of acne scarring using a dual-spot-size ablative fractionated carbon dioxide laser: review of the literature.

    Science.gov (United States)

    Tierney, Emily P

    2011-07-01

    Fractional photothermolysis has been reported in the literature to improve pigmentary and textural changes associated with acne scarring. To review the literature for the treatment of acne scarring using nonablative fractional laser (NAFL) and ablative fractional laser (AFL) resurfacing. Review of the Medline literature evaluating NAFL and AFL for acne scarring. NAFL and AFL are safe and effective treatments for acne scarring. It is likely that the controlled, limited dermal heating of fractional resurfacing initiates a cascade of events in which normalization of the collagenesis-collagenolysis cycle occurs. We present the results of a patient treated using a novel dual-spot-size AFL device. Three months after the final treatment, the patient reported 75% improvement in acne scarring and 63% overall improvement in photoaging. Fractionated resurfacing for the treatment of acne scarring is associated with lesser risks of side effects of prolonged erythema and risks of delayed-onset dyspigmentation and scarring which complicate traditional ablative laser resurfacing approaches. We present herein preliminary data suggesting that a dual-spot-size AFL device presents novel advantages of improving texture and pigmentation in acne scarring and photoaging. © 2011 by the American Society for Dermatologic Surgery, Inc.

  12. Real-time dynamic MLC tracking for inversely optimized arc radiotherapy

    DEFF Research Database (Denmark)

    Falk, Marianne; af Rosenschöld, Per Munck; Keall, Paul

    2010-01-01

    Motion compensation with MLC tracking was tested for inversely optimized arc radiotherapy with special attention to the impact of the size of the target displacements and the angle of the leaf trajectory.......Motion compensation with MLC tracking was tested for inversely optimized arc radiotherapy with special attention to the impact of the size of the target displacements and the angle of the leaf trajectory....

  13. Experience with carbon ion radiotherapy at GSI

    Energy Technology Data Exchange (ETDEWEB)

    Jaekel, O. [Division of Medical Physics in Radiation Therapy (E040), German Cancer Research Center, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)]. E-mail: o.jaekel@dkfz.de; Schulz-Ertner, D. [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Karger, C.P. [Division of Medical Physics in Radiation Therapy (E040), German Cancer Research Center, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Heeg, P. [Division of Medical Physics in Radiation Therapy (E040), German Cancer Research Center, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Debus, J. [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany)

    2005-12-15

    At GSI, a radiotherapy facility was established using beam scanning and active energy variation. Between December 1997 and April 2004, 220 patients have been treated at this facility with carbon ions. Most patients are treated for chordoma and chondrosarcoma of the base of skull, using a dose of 60 Gye (Gray equivalent) in 20 fractions. Carbon ion therapy is also offered in a combination with conventional radiotherapy for a number of other tumors (adenoidcystic carcinoma, chordoma of the cervical spine and sacrum, atypical menningeoma). The patients treated for skull base tumors showed an overall local control rate after two years of 90%. The overall treatment toxicity was mild. This shows that carbon ion radiotherapy can safely be applied using a scanned beam and encouraged the Heidelberg university hospital to build a hospital based facility for ion therapy.

  14. Fractionation schedules for cancers of the head and neck

    International Nuclear Information System (INIS)

    Harari, Paul M.

    1995-01-01

    Purpose/Objective: This refresher course reviews current research activity and treatment results in the field of radiation therapy fractionation. The presentation emphasizes worldwide studies of altered fractionation, highlighting head and neck cancer as the primary teaching model. Basic radiobiological principles guiding the development of altered fractionation regimens, and advancing the understanding of fractionation effects on normal and tumor tissue are reviewed. A 'standard' prescription of 2 Gy x 35 fractions = 70 Gy may not provide the optimal balance between primary tumor control and late normal tissue effects for all patients with squamous cell carcinoma of the head and neck. The last decade has witnessed the treatment of thousands of head and neck cancer patients with curative radiotherapy using altered fractination schedules designed to improve overall treatment results. Although the number of different fractionation regimens currently being investigated continues to increase, the common guiding principles behind their design are relatively simple. Common fractionation terminology (i.e., accelerated hyperfractionation) will be reviewed, as well as a brief summary of radiobiological concepts pertaining to tumor potential doubling time, tumor proliferation kinetics, overall treatment time and fraction size-dependence of acute and late tissue effects. Several well known head and neck fractionation schedules from around the world (Manchester Christie Hospital-United Kingdom, Princess Margaret Hospital-Canada, Massachusetts General Hospital-USA, MD Anderson Hospital-USA, University of Florida-USA, Mount Vernon Hospital CHART-United Kingdom, RTOG and EORTC trials-USA and Europe) will be summarized with regard to design-rationale, treatment technique and results. The design of several current cooperative group trials investigating altered head and neck fractionation will be presented, as well as concepts prompting the pilot evaluation of several brand new

  15. Radiotherapy of vertebral hemangiomas

    International Nuclear Information System (INIS)

    Sakata, Kohichi; Hareyama, Masato; Oouchi, Atushi; Sido, Mitsuo; Nagakura, Hisayasu; Tamakawa, Mituharu; Akiba, Hidenari; Morita, Kazuo

    1997-01-01

    Between 1975 and 1996, 14 patients (11 females, 3 males) with vertebral hemangioma received treatment with radiotherapy. Thirteen patients had a history of back pain or lumbago and 2 patients had neurological symptoms such as sensory impairment or paraplegia. The standard dose administered was 36 Gy in 18 fractions (five treatments per week). In the 13 patients with pain, this was completely or partially relieved. The condition of a man with hypesthesia of the legs deteriorated and a woman with paraplegia who was treated with decompressive laminectomy followed by radiotherapy recovered completely after irradiation. CT scan before irradiation showed thickened trabeculae as small punctate areas of sclerosis in all patients. At MR imaging before irradiation, T2-weighted MR images showed areas of high intensity in all patients and MR images demonstrated lesion enhancement. However, none of the patients who were treated successfully with radiation demonstrated any changes of the affected vertebra in the conventional radiographic films, CT scan or MR imaging, even 5 years after irradiation. Radiological imaging is indispensable for the diagnosis of vertebral hemangiomas but does not appear to be useful for evaluating the effects of radiotherapy. (orig.)

  16. Acoustic neuromas: single dose vs fractionated therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fuss, M; Debus, J; Lohr, F; Engenhart-Cabillic, R; Wannenmacher, M

    1997-07-01

    Purpose: Radiosurgical treatment (RS) of acoustic neuromas is a well established treatment. However, few data are available concerning conformal fractionated radiotherapy (FT) of this tumor entity. We evaluated treatment outcome and toxicity for both treatment modalities in 41 patients treated at our institution between 1984 and 1997. Material and Methods: All treatments were performed using a specially adapted linear accelerator and circular collimators for convergent beam RS or multi-leaf collimators (leaf thickness 1 or 3mm) for multi-field RS or fractionated treatment. 22 patients (7 male, 15 female, median age 60 years, range 20-83 years) were treated radiosurgically with single doses between 7 and 28 Gray (median 15 Gy) prescribed to the 80% isodose line. Tumor volumes ranged from 0.7 to 10.5 ccm with a median volume of 3.4 ccm. The median number of isocenters was 2 (1-4 isocenters). One patient was treated by a multi-field technique (14 isocentric irregularly shaped noncoplanar fields). 19 patients (5 male, 14 female, median age 55 years, range 20-81 years) were treated with stereotactic conformal radiotherapy. Median dose was 60 Gray with a median daily fraction size of 2 Gy and a median of 3 (1-4) irregularly shaped isocentric fields. Tumor volumes ranged from 0.7 to 32.4 ccm (median 15 ccm). Median follow-up was 30 months (7-149 months) for radiosurgical and 30 months (2-88 months) for fractionated treatment. Seven patients who underwent fractionated treatment had previously undergone neurosurgical resection on the contralateral side. One had undergone radiosurgery on the opposite side before. Results: All tumors were locally controlled. A volume reduction of more than 20% was seen in 16% after RS and 18% following FT. Typical posttherapeutic central reduction of contrast media enhancement was found in 73% following RS after a median of 8 (3-12) months and in 63% following FT after a median of 6 (1-12) months. Temporary brainstem edema was diagnosed in 4

  17. Post-external radiotherapy hypothyroidism: 15 cases

    International Nuclear Information System (INIS)

    Kaffel, N.; Mnif, M.; Abid, M.; Daoud, J.

    2001-01-01

    Post-external radiotherapy hypothyroidism: 15 cases. Hypothyroidism frequency is estimated to be between 10 and 45% after radiotherapy alone, and 40 to 67% after radiotherapy associated with thyroidectomy. This hypothyroidism is infra-clinical in 60% of the cases. Our study concerned 15 cases of hypothyroidism after external radiotherapy delivered between and 1991 and 1999. An irradiation of the cervical, cerebral and thorax regions was indicated for different types of cancers. Larynx carcinoma epidermoid was the most frequent cancer (seven cases); the radiation treatment used cobalt 60 with conventional fractionation, i.e., 2 Gy per treatment, five treatments a week. In nine cases, the hypothyroidism was discovered during a systematic examination; it was clinically evident in the six remaining cases. Hypothyroidism appeared after an irradiation dose average of 50 Gy (extremes 30-65 Gy). The average duration of the irradiation was about 7 weeks and the hypothyroidism appeared in a mean 22 months. In all cases, the substituting treatment was initiated with a favorable progression. Faced with the risk of hypothyroidism, it is necessary to check patients who have undergone external irradiation of the neck. (authors)

  18. Accelerated hyperfractionated radiotherapy for malignant gliomas

    International Nuclear Information System (INIS)

    Buatti, John M.; Marcus, Robert B.; Mendenhall, William M.; Friedman, William A.; Bova, Francis J.

    1996-01-01

    Purpose: To evaluate accelerated hyperfractionated radiotherapy for the treatment of malignant gliomas. Methods and Materials: Between April 1985 and June 1994, 70 adult patients with pathologically confirmed malignant glioma (75% glioblastoma multiforme, 25% anaplastic astrocytoma) suitable for high-dose therapy were selected for treatment with accelerated hyperfractionated radiotherapy, 1.5 Gy twice daily to a total target dose of 60 Gy. Two patients were excluded from analysis (one patient had a fatal pulmonary embolism after 18 Gy; one patient discontinued therapy after 28.5 Gy against medical advice and without sequelae or progression). The 68 patients in the study group had a median age of 52 years and a median Karnofsky performance status of 90. Stereotactic implant ( 125 I) or stereotactic radiosurgery boosts were delivered to 16 patients (24%) in the study group. Minimum follow-up was 6 months. Results: Median survival was 13.8 months and median progression-free survival was 7.4 months. The absolute Kaplan-Meier survival rate was 16% at 2 years and 4% at 5 years. Multivariate analysis for the prognostic impact of age, gender, histology, Karnofsky performance status, symptomatology, surgical resection vs. biopsy, and boost vs nonboost therapy revealed that Karnofsky performance status ≥ 90, boost therapy, and surgical excision predicted significantly improved outcome. No severe toxicity occurred in patients treated with accelerated hyperfractionated radiotherapy alone, although 5% required steroids temporarily for edema. Progression occurred during treatment in one patient (1.5%). Conclusion: This regimen of accelerated hyperfractionated radiotherapy is well tolerated and leads to results comparable with those of standard therapy. The rate of disease progression during treatment is significantly better (p = 0.001) than is reported for patients treated with standard fractionation, with or without chemotherapy. This regimen is a reasonable starting point

  19. Fractionated stereotactic irradiation by Cyberknife of choroid melanomas: repositioning validation, closed eyelids

    International Nuclear Information System (INIS)

    Horn, S.; Rezvoy, N.; Lacornerie, T.; Mirabel, X.; Labalette, P.; Lartigau, E.

    2009-01-01

    The fractionated stereotactic radiotherapy by Cyberknife is an option in the treatment of eyes tumors. The advantages of the Cyberknife in the choroid melanomas are in its infra-millimetric precision, to the automated repositioning on the skull bones and to the conformity brought by the stereotaxy. The objective of this study was to validate the quality of repositioning and the immobility of the eyes with closed eyelids. Conclusion: the reproducibility of the eye positioning with closed eyelids seems enough to consider the conservative treatment of choroid melanomas by fractionated stereotactic radiotherapy by Cyberknife without implementation of fiducials nor retrobulbar anaesthesia. (N.C.)

  20. Treatment of symptomatic vertebral hemangioma by radiotherapy - case report and review of the literature

    International Nuclear Information System (INIS)

    Castro, Douglas Guedes de; Lima, Renato Pierre; Maia, Maria Aparecida Conte; Pellizzon, Antonio Cassio Assis; Fogaroli, Ricardo Cesar; Ferrigno, Robson

    2002-01-01

    We report the clinical and imaging findings of a patient with a symptomatic vertebral hemangioma treated with radiotherapy alone. There was partial relief of the pain 3 months after radiotherapy. We recommend a total dose of 40 Gy at 2 Gy per fraction. A review of literature is also presented. (author)

  1. Characterization of the Particle Size Fraction associated with Heavy Metals in Suspended Sediments of the Yellow River

    Directory of Open Access Journals (Sweden)

    Qingzhen Yao

    2015-06-01

    Full Text Available Variations in the concentrations of particulate heavy metals and fluxes into the sea in the Yellow River were examined based on observational and measured data from January 2009 to December 2010. A custom-built water elutriation apparatus was used to separate suspended sediments into five size fractions. Clay and very fine silt is the dominant fraction in most of the suspended sediments, accounting for >40% of the samples. Cu, Pb, Zn, Cr, Fe and Mn are slightly affected by anthropogenic activities, while Cd is moderate affected. The concentrations of heavy metals increased with decrease in particle size. For suspended sediments in the Yellow River, on average 78%–82% of the total heavy metal loading accumulated in the <16 μm fraction. About 43% and 53% of heavy metal in 2009 and 2010 respectively, were readily transported to the Bohai Sea with “truly suspended” particles, which have potentially harmful effects on marine organisms.

  2. Particle-size fractionation and stable carbon isotope distribution applied to the study of soil organic matter dynamics

    International Nuclear Information System (INIS)

    Cerri, C.; Feller, C.; Balesdent, J.; Victoria, R.; Plenecassagne, A.

    1985-01-01

    The present Note concerns the dynamics of organic matter in soils under forest (C 3 -type vegetation) and 12 and 50 years old sugar-cane (C 4 -type vegetation) cultivation. The decomposition rate of ‘forest organic matter” and the accumulation rate of “sugar-cane organic matter” are estimated through 13 C measurements of total soil and different organic fractions (particle-size, fractionation) [fr

  3. Approaches to radiotherapy in metastatic spinal cord compression.

    Science.gov (United States)

    Suppl, Morten Hiul

    2018-04-01

    Metastatic spinal cord compression is caused by the progression of metastatic lesions within the vicinity of the spinal cord. The consequences are very severe with loss of neurological function and severe pain. The standard treatment is surgical intervention followed by radiotherapy or radiotherapy alone. However, the majority of patients are treated with radiotherapy only due to contraindications to surgery and technical inoperability. Stereotactic body radiotherapy is a technology to deliver higher radiation dose to the radiotherapy target with the use of spatial coordinates. This modality has shown positive results in treating lesions in brain and lungs. Hence, it could prove beneficial in metastatic spinal cord compression. We designed and planned a trial to investigate this method in patients with metastatic spinal cord compression. The method was usable but the trial was stopped prematurely due to low accrual that made comparison with surgery impossible. Low accrual is a known problem for trials evaluating new approaches in radiotherapy. Target definition in radiotherapy of metastatic spinal cord compression is defined by patient history, examination and imaging. Functional imaging could provide information to guide target definition with the sparring of normal tissue e.g. spinal cord and hematopoietic tissue of the bone marrow. In future trials this may be used for dose escalation of spinal metastases. The trial showed that PET/MRI was feasible in this group of patients but did not change the radiotherapy target in the included patients. Neurological outcome is similar irrespective of course length and therefore single fraction radiotherapy is recommended for the majority of patients. In-field recurrence is a risk factor of both short and long fractionation schemes and re-irradiation have the potential risk of radiation-induced myelopathy. In a retrospective study of re-irradiation, we investigated the incidence of radiation-induced myelopathy. In our study

  4. Comparative Mineralogy, Microstructure and Compositional Trends in the Sub-Micron Size Fractions of Mare and Highland Lunar Soils

    Science.gov (United States)

    Thompson, M. S.; Christoffersen, R.; Noble, S. K.; Keller, L. P.

    2012-01-01

    The morphology, mineralogy, chemical composition and optical properties of lunar soils show distinct correlations as a function of grain size and origin [1,2,3]. In the fraction, there is an increased correlation between lunar surface properties observed through remote sensing techniques and those attributed to space weathering phenomenae [1,2]. Despite the establishment of recognizable trends in lunar grains fraction fraction for both highland and mare derived soils. The properties of these materials provide the focus for many aspects of lunar research including the nature of space weathering on surface properties, electrostatic grain transport [4,5] and dusty plasmas [5]. In this study, we have used analytical transmission and scanning transmission electron microscopy (S/TEM) to characterize the mineralogy type, microstructure and major element compositions of grains in this important size range in lunar soils.

  5. Modern possibilities of radiotherapy in the complex and single treatment of panaris

    International Nuclear Information System (INIS)

    Kolipiliev, V.; Momchev, M.

    1979-01-01

    Results are reported of the treatment of 282 patients with different forms of panaris: 39 per cent received radiotherapy alone, in the remaining radiotherapy was combined with surgical management, antibiotics and local treatment. Two different radiotherapy schemes were attempted: 49% of the patients received rather high single (50-80 rad) and total (300-600 rad) doses in the local site at a regimen of superficial (100 kV, 4 mm Al) or deep (180-200 kV, 0.5-1 mm Cu) roentgentherapy, with size of field 4/4 cm or 4/6 cm and 30-40 cm distance. In the remaining 51% of patients radiotherapy was characterized by dynamic fractionation and longer duration of procedures with significantly lower single (30-40 rad) and total (160-320 rad) doses. In recent years the second scheme has been preferred and has gain wide acceptance. Irradiation dose and rate invariably conformed to the type of inflammatory process. Patients with panaritium paronychium and panaritium subcutaneum admitted for treatment in the first few days of development of the digital infection required only several procedures on alternate days to achieve complete cure in a week. In the event of pus collection, 1 or 2 irradiation procedures accelerated abscess formation; this was followed by surgical intervention with postoperative radiotherapy to hasten the granulation process. Treatment of bone-and-joint forms of panaris was complex with initially higher single doses, followed by lower ones, applied up to twice weekly. The following advantages of the method are pointed out: shortening of treatment, respectively of the disability period; easy to perform, painless and practically innocuous manipulation. Complete cure could not be achieved only in advanced, torpid cases. (A.B.)

  6. Item 141 Radiotherapy. Radiobiological notions; main secondary effects

    International Nuclear Information System (INIS)

    Azria, David; Dubois, Jean-Bernard

    2006-11-01

    This document first gives definitions of ionizing radiations, photons, electrons and Gray (as a dose unit). It describes the mechanisms of action of ionizing radiations: physical, chemical, cellular actions, actions on tissues. It analyses and discusses the factors influencing the effects of radiations: intrinsic radio-sensitivity, cellular cycle, oxygen, time (session fractioning and organisation in time), and dose. The different types of radiotherapy are then presented: external radiotherapy, brachytherapy, radio-immunotherapy of internal radiotherapy. It discusses tissues tolerance doses and doses required to sterilize tumours, and discusses the various and main secondary effects: stochastic secondary effects and deterministic secondary effects. A table indicates possible early and late reactions for different organs (skin, lung, brain, medulla, nerves, oesophagus, heart, pancreas, stomach, liver, intestine, kidney, bladder, rectum, ENT, or eye's lens)

  7. Single fraction versus multiple fraction radiotherapy for palliation of painful vertebral bone metastases: A prospective study

    Directory of Open Access Journals (Sweden)

    Dipanjan Majumder

    2012-01-01

    Conclusions: Different fractionation of radiation has same response and toxicity in treatment of vertebral bone metastasis. Single fraction RT may be safely used to treat these cases as this is more cost effective and less time consuming. Studies may be conducted to find out particular subgroup of patients to be benefitted more by either fractionation schedule; however, our study cannot comment on that issue.

  8. Hypo-fractionated treatment in radiotherapy: radio-biological models Tcp and NTCP; Tratamiento hipofraccionado en radioterapia: modelos radiobiologicos TCP y NTCP

    Energy Technology Data Exchange (ETDEWEB)

    Astudillo V, A. J.; Mitsoura, E. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, 50180 Toluca, Estado de Mexico (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Resendiz G, G., E-mail: lydia.paredes@inin.gob.mx [Hospital Medica Sur, Departamento de Radioterapia, Puente de Piedra 150, Col. Toriello Guerra, 14050 Mexico D. F. (Mexico)

    2014-08-15

    At the present time the breast cancer in Mexico has the first place of incidence of the malignant neoplasia s in the women, and represents 11.34% of all the cancer cases. On the other hand, the treatments for cancer by means of ionizing radiations have been dominated under the approaches of the medical radio-oncologists which have been based on test and error by many years. The radio-biological models, as the Tcp, NTCP and dosimetric variables, for their clinical application in the conventional radiotherapy with hypo-fractionation have as purpose predicting personalized treatment plans that they present most probability of tumor control and minor probability of late reactions, becoming this way support tools in the decisions taking for the patient treatments planning of Medical Physicists and Radio-oncologists. (Author)

  9. The development of radiotherapy in Slovenia

    International Nuclear Information System (INIS)

    Kuhelj, Janez; Ravnihar, Bozena

    1996-01-01

    The historical data on the development of radiotherapy in Slovenia are presented from its first use in this county in 1902 until the present. The Institute of Oncology in Ljubljana was established in 1938 with the intention of providing a sound development of radium and roentgen cancer treatment. After World War II, the development of radiotherapy was dynamic, which is evident from the data on new radiation sources in external beam therapy (accelerators, telecobalt units), in brachytherapy (various sealed radioisotopes) as well as in the introduction of therapy with unsealed radioisotopes. In 1947, a Chair of Oncology and Radiotherapy was instituted at the Medical Faculty of the University of Ljubljana (with the seat at the Institute of Oncology). In 1955, radiotherapy and oncology were officially recognized as separate branches of medicine requiring special obligatory postgraduate residency training. Within the Medical Society of Slovenia, the Section for Radiotherapy was established in 1987. The following year, the Section for Radiotherapy of Slovenia became a member of the European Society for Therapeutic Radiology and Oncology. Considering the size of population of Slovenia (nearly 2 million), it was reasonable that by this time radiotherapy became almost completely concentrated in one central institution, the Institute of Oncology, whose core and cohesive activity were represented in the multidisciplinary cancer treatment approach

  10. [Cost analysis of radiotherapy provided in inpatient setting -  testing potential predictors for a new prospective payment system].

    Science.gov (United States)

    Sedo, J; Bláha, M; Pavlík, T; Klika, P; Dušek, L; Büchler, T; Abrahámová, J; Srámek, V; Slampa, P; Komínek, L; Pospíšil, P; Sláma, O; Vyzula, R

    2014-01-01

    As a part of the development of a new prospective payment model for radiotherapy we analyzed data on costs of care provided by three comprehensive cancer centers in the Czech Republic. Our aim was to find a combination of variables (predictors) which could be used to sort hospitalization cases into groups according to their costs, with each group having the same reimbursement rate. We tested four variables as possible predictors -  number of fractions, stage of disease, radiotherapy technique and diagnostic group. We analyzed 7,440 hospitalization cases treated in three comprehensive cancer centers from 2007 to 2011. We acquired data from the I COP database developed by Institute of Biostatistics and Analyses of Masaryk University in cooperation with oncology centers that contains records from the National Oncological Registry along with data supplied by healthcare providers to insurance companies for the purpose of retrospective reimbursement. When comparing the four variables mentioned above we found that number of fractions and radiotherapy technique were much stronger predictors than the other two variables. Stage of disease did not prove to be a relevant indicator of cost distinction. There were significant differences in costs among diagnostic groups but these were mostly driven by the technique of radiotherapy and the number of fractions. Within the diagnostic groups, the distribution of costs was too heterogeneous for the purpose of the new payment model. The combination of number of fractions and radiotherapy technique appears to be the most appropriate cost predictors to be involved in the prospective payment model proposal. Further analysis is planned to test the predictive value of intention of radiotherapy in order to determine differences in costs between palliative and curative treatment.

  11. Verification of respiratory-gated radiotherapy with new real-time tumour-tracking radiotherapy system using cine EPID images and a log file

    Science.gov (United States)

    Shiinoki, Takehiro; Hanazawa, Hideki; Yuasa, Yuki; Fujimoto, Koya; Uehara, Takuya; Shibuya, Keiko

    2017-02-01

    A combined system comprising the TrueBeam linear accelerator and a new real-time tumour-tracking radiotherapy system, SyncTraX, was installed at our institution. The objectives of this study are to develop a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine electronic portal image device (EPID) images and a log file and to verify this treatment in clinical cases. Respiratory-gated radiotherapy was performed using TrueBeam and the SyncTraX system. Cine EPID images and a log file were acquired for a phantom and three patients during the course of the treatment. Digitally reconstructed radiographs (DRRs) were created for each treatment beam using a planning CT set. The cine EPID images, log file, and DRRs were analysed using a developed software. For the phantom case, the accuracy of the proposed method was evaluated to verify the respiratory-gated radiotherapy. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker used as an internal surrogate were calculated to evaluate the gating accuracy and set-up uncertainty in the superior-inferior (SI), anterior-posterior (AP), and left-right (LR) directions. The proposed method achieved high accuracy for the phantom verification. For the clinical cases, the intra- and inter-fractional variations of the fiducial marker were  ⩽3 mm and  ±3 mm in the SI, AP, and LR directions. We proposed a method for the verification of respiratory-gated radiotherapy with SyncTraX using cine EPID images and a log file and showed that this treatment is performed with high accuracy in clinical cases. This work was partly presented at the 58th Annual meeting of American Association of Physicists in Medicine.

  12. Combined radiotherapy-chemotherapy

    International Nuclear Information System (INIS)

    Steel, G.G.

    1989-01-01

    This paper presents the clinically confirmed benefits of combined chemotherapy-radiotherapy. They have been found in a small group of diseases that respond to chemotherapy alone. According to the author, only when a drug or drug combination has the ability to eradicate occult disease or substantially to reduce the size of objectively measurable disease is there likely to be an demonstrable benefit from its use in conjunction with radiotherapy. It is the author's belief that the immediate future lies in selecting drugs and patients in which a good chemotherapeutic response can be expected, avoiding drugs that seriously enhance radiation damage to normal tissues and keeping drug and radiation treatments far enough apart in time to minimize interactions

  13. Bacterial Preferences for Specific Soil Particle Size Fractions Revealed by Community Analyses

    DEFF Research Database (Denmark)

    Hemkemeyer, Michael; Dohrmann, Anja B.; Christensen, Bent Tolstrup

    2018-01-01

    Genetic fingerprinting demonstrated in previous studies that differently sized soil particle fractions (PSFs; clay, silt, and sand with particulate organic matter (POM)) harbor microbial communities that differ in structure, functional potentials and sensitivity to environmental conditions....... To elucidate whether specific bacterial or archaeal taxa exhibit preference for specific PSFs, we examined the diversity of PCR-amplified 16S rRNA genes by high-throughput sequencing using total DNA extracted from three long-term fertilization variants (unfertilized, fertilized with minerals, and fertilized...

  14. Real-time 3D-surface-guided head refixation useful for fractionated stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Li Shidong; Liu Dezhi; Yin Gongjie; Zhuang Ping; Geng, Jason

    2006-01-01

    Accurate and precise head refixation in fractionated stereotactic radiotherapy has been achieved through alignment of real-time 3D-surface images with a reference surface image. The reference surface image is either a 3D optical surface image taken at simulation with the desired treatment position, or a CT/MRI-surface rendering in the treatment plan with corrections for patient motion during CT/MRI scans and partial volume effects. The real-time 3D surface images are rapidly captured by using a 3D video camera mounted on the ceiling of the treatment vault. Any facial expression such as mouth opening that affects surface shape and location can be avoided using a new facial monitoring technique. The image artifacts on the real-time surface can generally be removed by setting a threshold of jumps at the neighboring points while preserving detailed features of the surface of interest. Such a real-time surface image, registered in the treatment machine coordinate system, provides a reliable representation of the patient head position during the treatment. A fast automatic alignment between the real-time surface and the reference surface using a modified iterative-closest-point method leads to an efficient and robust surface-guided target refixation. Experimental and clinical results demonstrate the excellent efficacy of <2 min set-up time, the desired accuracy and precision of <1 mm in isocenter shifts, and <1 deg. in rotation

  15. Fractionated stereotactic radiation therapy for intracranial benign tumor : preliminary results of clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Yong; Ahn, Yong Chan; Huh, Seung Jae [Samsung Medical Center, Syungkyunkwan Univ. College of Medicine, Seoul (Korea, Republic of)] (and others)

    1998-06-01

    With the development of stereotactic immobilization systems capable of reliable serial repositioning, fractionated stereotactic radiation therapy(FSRT) offers the potential for an improved treatment outcome by excellent dose delivery, and dose distribution characteristics with the favorable radio-biological properties of fractionated irradiation. We describe our initial experience using FSRT for the treatment of intracranial benign tumor. Between August 1995 and December 1996, 15 patients(7 males and 8 females aged 6-70 years) were treated with FSRT. The patients had the following diagnosis : pituitary adenoma(10) including one patient who previously had received radiotherapy, craniopharyngioma(2), acoustic neurinoma(1), meningioma(2). Using the Gill-Thomas-Cos-man relocatable head frame and multiple non-coplanar therapy, the daily dose of 2Gy was irradiated at 90% to 100% isodose surface of the isocenter. The collimator sizes ranged from 26mm to 70mm. In all patients except one follow-up lost, disease was well-controlled. Acute complication was negligible and no patient experienced cranial nerve neuropathies and radiation necrosis. In overall patient setup with scalp measurements, reproducibility was found to have mean of 1.1{+-}0.6mm from the baseline reading. Relocatable stereotactic system for FSRT is highly reproducible and comfortable. Although the follow-up period was relatively short, FSRT is considered to be a safe an effective radiation technique as the treatment of intracranial tumor. But the fractionation schedule(fraction size, overall treatment time and total dose) still remains to be solved by further clinical trials.

  16. Conformity Index and Homogeneity Index of the Postoperative Whole Breast Radiotherapy.

    Science.gov (United States)

    Petrova, Deva; Smickovska, Snezana; Lazarevska, Emilija

    2017-10-15

    The treatment of breast cancer involves a multidisciplinary approach in which radiotherapy plays a key role. The conformity index and the homogeneity index are two analysis tools of a treatment plan using conformal radiotherapy. The purpose of this article is an analysis of these two parameters in the assessment of the treatment plans in 58 patients undergoing postoperative radiotherapy of the whole breast. All 58 patients participating in the study had a conservatively treated early-stage breast cancer. The treatment was performed using a standard regimen of fractionation in 25 fractions up to a total dose of 50 Gy. Dose-volume histograms were generated for both plans with and without segmental fields. Pair samples t-test was used. The technique with segmental fields allowed us more homogeneity distribution when compared to standard two tangential field techniques. The HI values were 1.08 ± 0.01 and 1.09 ± 0.01 for segment and technique with two tangential fields (p conformity and the homogeneity index are important tools in the analysis of the treatment plans during radiation therapy in patients with early-stage breast cancer. Adding segment fields in the administration of radiotherapy in patients with conservatively treated breast cancer can lead to improved dosage homogeneity and conformity.

  17. A procedure for partitioning bulk sediments into distinct grain-size fractions for geochemical analysis

    Science.gov (United States)

    Barbanti, A.; Bothner, Michael H.

    1993-01-01

    A method to separate sediments into discrete size fractions for geochemical analysis has been tested. The procedures were chosen to minimize the destruction or formation of aggregates and involved gentle sieving and settling of wet samples. Freeze-drying and sonication pretreatments, known to influence aggregates, were used for comparison. Freeze-drying was found to increase the silt/clay ratio by an average of 180 percent compared to analysis of a wet sample that had been wet sieved only. Sonication of a wet sample decreased the silt/clay ratio by 51 percent. The concentrations of metals and organic carbon in the separated fractions changed depending on the pretreatment procedures in a manner consistent with the hypothesis that aggregates consist of fine-grained organic- and metal-rich particles. The coarse silt fraction of a freeze-dried sample contained 20–44 percent higher concentrations of Zn, Cu, and organic carbon than the coarse silt fraction of the wet sample. Sonication resulted in concentrations of these analytes that were 18–33 percent lower in the coarse silt fraction than found in the wet sample. Sonication increased the concentration of lead in the clay fraction by an average of 40 percent compared to an unsonicated sample. Understanding the magnitude of change caused by different analysis protocols is an aid in designing future studies that seek to interpret the spatial distribution of contaminated sediments and their transport mechanisms.

  18. Radiotherapy of nonfunctional adenomas of the pituitary gland. Results with long-term follow-up

    International Nuclear Information System (INIS)

    Flickinger, J.C.; Nelson, P.B.; Martinez, A.J.; Deutsch, M.; Taylor, F.

    1989-01-01

    A total of 112 patients with the diagnosis of nonfunctional pituitary adenoma received radiation therapy at the University of Pittsburgh between 1964 and 1987. Postoperative radiation therapy was administered in 87 patients. Actuarial progression-free survival (tumor control) at 5, 10, 15, and 20 years was 97%, 89%, 87%, and 76%, respectively. Radiation prescribed to the 95% isodose ranged from 35.72 Gy to 62.32 Gy. Multivariate analysis showed decreased tumor control to be significantly associated with increasing field size (P = .036). No improvement in tumor control could be detected with increasing total radiation dose or nominal standard dose (NSD). One patient developed optic neuropathy and another developed a glioblastoma after doses in both patients of 4750 cGy in 25 fractions. External beam radiotherapy for nonfunctional pituitary adenomas was found to be effective and safe when doses less than 4750 cGy in 25 fractions were used

  19. The Effect of Aggregate-Size Fractions on the Availability of Cu in Some Contaminated Soils with Heavy Metals

    Directory of Open Access Journals (Sweden)

    Akram Farshadirad

    2017-06-01

    Full Text Available Introduction: In recent years, because of the presence of industrial factories around the Isfahan province of Iran and high concentrations of heavy metals in the vicinity of them, and the gradual accumulation of heavy metals from various sources of pollution in urban areas over time, including gasoline combustion, and use of urban waste compost and sewage sludge as fertilizer, there has been widespread concerned regarding the human health problems with increasing heavy metals in soils around the Isfahan city. The variation of composition in the soil matrix may lead to variation of composition and behavior of soil heavy metals. Soil is a heterogeneous body of materials and soil components are obviously in interaction. Studies tacking this complexity often use aggregate measurements as surrogates of the complex soil matrix. So, it is important the understanding soil particle-size distribution of aggregates and its effects on heavy metal partitioning among the size fractions, the fate of metals and their toxicity potential in the soil environment. Therefore, the present study aimed to determine the Cu release potential from different size fractions of different polluted soils by different extractants and their availability for corn plant. Materials and Methods: Five soil samples were collected from the surface soils (0–15 cm of Isfahan province, in central of Iran. The soil samples were air-dried and ground to pass a 2-mm sieve for laboratory analysis. Air dried samples fractionated into four different aggregate size fractions 2.0–4.0 (large macro-aggregate, 0.25–2 (small macro-aggregate, 0.05–0.25 (micro-aggregate, and

  20. Neural Stem Cell-Preserving External-Beam Radiotherapy of Central Nervous System Malignancies

    International Nuclear Information System (INIS)

    Barani, Igor J.; Cuttino, Laurie W.; Benedict, Stanley H.; Todor, Dorin; Bump, Edward A.; Wu Yan; Chung, Theodore D.; Broaddus, William C.; Lin, Peck-Sun

    2007-01-01

    Purpose: Recent discoveries have implicated neural stem cells (NSC) as the source of plasticity and repair in the mature mammalian brain. Treatment-induced NSC dysfunction may lead to observed toxicity. This study evaluates the feasibility of NSC-preserving external beam radiotherapy. Methods and Materials: A single computed tomography (CT) dataset depicting a right periventricular lesion was used in this study as this location reflects the most problematic geometric arrangement with respect to NSC preservation. Conventional and NSC preserving radiotherapy (RT) plans were generated for the same lesion using two clinical scenarios: cerebral metastatic disease and primary high-grade glioma. Disease-specific target volumes were used. Metastatic disease was conventionally treated with whole-brain radiotherapy (WBRT) to 3,750 cGy (15 fractions) followed by a single stereotactic radiosurgery (SRS) boost of 1,800 cGy to gross disease only. High-grade glioma was treated with conventional opposed lateral and anterior superior oblique beams to 4,600 cGy (23 fractions) followed by a 1,400 cGy (7 fractions) boost. NSC preservation was achieved in both scenarios with inverse-planned intensity modulated radiotherapy (IMRT). Results: Cumulative dose reductions of 65% (metastatic disease) and 25% (high-grade glioma) to the total volume of the intracranial NSC compartments were achieved with NSC-preserving IMRT plans. The reduction of entry and exit dose to NSC niches located contralateral to the target contributed most to NSC preservation. Conclusions: Neural stem cells preservation with current external beam radiotherapy techniques is achievable in context of both metastatic brain disease and high-grade glioma, even when the target is located adjacent to a stem cell compartment. Further investigation with clinical trials is warranted to evaluate whether NSC preservation will result in reduced toxicity