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Sample records for adjuvant external beam

  1. The role of adjuvant external beam radiation therapy for papillary thyroid carcinoma invading the trachea

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    Kim, Young Suk; Choi, Jae Hyuck; Kim, Kwang Sik [Jeju National University Hospital, Jeju National University School of Medicine, Jeju (Korea, Republic of); and others

    2017-06-15

    To evaluate the effect of adjuvant external beam radiation therapy (EBRT) on local failure-free survival rate (LFFS) for papillary thyroid cancer (PTC) invading the trachea. Fifty-six patients with locally advanced PTC invading the trachea were treated with surgical resection. After surgery, 21 patients received adjuvant EBRT and radioactive iodine therapy (EBRT group) and 35 patients were treated with radioactive iodine therapy (control group). The age range was 26–87 years (median, 56 years). The median follow-up period was 43 months (range, 4 to 145 months). EBRT doses ranged from 50.4 to 66 Gy (median, 60 Gy). Esophagus invasion and gross residual disease was more frequent in the EBRT group. In the control group, local recurrence developed in 9 (9/35, 26%) and new distant metastasis in 2 (2/35, 6%) patients, occurring 4 to 68 months (median, 37 months) and 53 to 68 months (median, 60 months) after surgery, respectively. Two patients had simultaneous local recurrence and new distant metastasis. There was one local failure in the EBRT group at 18 months after surgery (1/21, 5%). The 5-year LFFS was 95% in the EBRT group and 63% in the control group (p = 0.103). In the EBRT group, one late grade 2 xerostomia was developed. Although, EBRT group had a higher incidence of esophagus invasion and gross residual disease, EBRT group showed a better 5-year LFFS. Adjuvant EBRT may have contributed to the better LFFS in these patients.

  2. Adjuvant high-dose-rate brachytherapy after external beam radiotherapy in nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Oezyar, Enis; Yildz, Ferah; Akyol, Fadil H.; Atahan, I. Lale

    2002-01-01

    Purpose: To compare the local control and survival rates obtained with either external beam radiation therapy (ERT) and adjuvant high-dose-rate (HDR) brachytherapy (BRT) or ERT alone in patients with nasopharyngeal cancer. Methods and Materials: Between December 1993 and December 1999, 144 patients (106 male, 38 female) with the diagnosis of nasopharyngeal cancer were treated with either ERT and adjuvant HDR BRT (Group A) or ERT alone (Group B) at our department. BRT was not applied in 38 patients for the following reasons: (1) Unit was unavailable (n=13), (2) Patient was younger than 18 years (n=17), (3) Patient received accelerated hyperfractionated ERT (n=6), and (4) Patient refused BRT (n=2). The median age for whole group was 43 (range: 9-82 years). According to the AJCC-1997 staging system, there were 11 (7.6%), 35 (24.3%), 38 (26.4%), and 60 (41.7%) patients in Stage I, II, III, and IV, respectively. There were 57 (39.6%) patients with T1, 41 (28.5%) with T2, 20 (13.9%) with T3, and 26 (18.1%) with T4 tumors. Histopathologic diagnosis was WHO 2-3 in 137 (95.2%) patients. ERT doses ranged between 58.8 and 74 Gy (median: 66 Gy). There were significantly more patients with young age, N2 status, and Stage III disease in Group B and with Stage II disease in Group A. Significantly more patients received chemotherapy in Group B. BRT with an HDR 192 Ir microSelectron afterloading unit was delivered in 106 patients at the conclusion of ERT using a single-channel nasal applicator. Dose was prescribed at 1 cm from the source, and total dose of 12 Gy in 3 fractions on 3 consecutive days was given immediately after ERT. Besides radiotherapy, 82 (56.9%) patients received cisplatin-based chemotherapy, as well. Follow-up time ranged between 12 and 80 months (median: 32 months). Results: The two groups were comparable in terms of local recurrence, locoregional failure, regional failure, and rate of distant metastasis. Local failure was observed in 11 (10.3%) out of 106

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

    International Nuclear Information System (INIS)

    Biermann, M.; Pixberg, M.K.; Schober, O.; Schuck, A.; Willich, N.; Heinecke, A.; Koepke, W.; Schmid, K.W.; Dralle, H.

    2003-01-01

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

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

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

    2013-09-15

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

  5. Adjuvant external beam radiation therapy with concurrent chemotherapy in the management of gallbladder carcinoma

    International Nuclear Information System (INIS)

    Kresl, John J.; Schild, Steven E.; Henning, George T.; Gunderson, Leonard L.; Donohue, John; Pitot, Henry; Haddock, Michael G.; Nagorney, David

    2002-01-01

    Purpose: This study was performed to evaluate the outcome of patients with gallbladder cancer who received postoperative concurrent chemotherapy and radiation therapy. Methods and Materials: Curative resection followed by adjuvant combined modality therapy with external beam radiation therapy (EBRT) and chemotherapy was attempted in 21 consecutive gallbladder carcinoma (GBC) patients at the Mayo Clinic from 1985 through 1997. All patients received concurrent 5-fluorouracil during EBRT. EBRT fields encompassed the tumor bed and regional lymph nodes (median dose of 54 Gy in 1.8-2.0-Gy fractions). One patient received 15 Gy intraoperatively after EBRT. A retrospective analysis was performed for the end points of local control, distant failure, and overall survival. Results: After maximal resection, 12 patients had no residual disease on pathologic evaluation, 5 had microscopic residual disease, and 4 had gross residual disease. One patient had Stage I disease, and 20 had Stage III-IV disease. With median follow-up of 5 years (range: 2.6-11.5 years), 5-year survival for the entire cohort was 33%. The 5-year survival rate of patients with Stage I-III disease was 65% vs. 0% for those with Stage IV disease (p 54 Gy (microscopic residual, 3 patients; gross residual, 1 patient; negative but narrow margins, 2 patients) vs. 65% for the 15 who received a lower dose (3, gross residual; 2, microresidual; 10, negative margins). Conclusion: Patients with completely resected (negative margins) GBC followed by adjuvant EBRT plus 5-fluorouracil chemotherapy had a relatively favorable prognosis, with a 5-year survival rate of 64%. These results seem to be superior to historical surgical controls from the Mayo Clinic and other institutions, which report 5-year survival rates of approximately 33% with complete resection alone. Both tumor stage and extent of resection seemed to influence survival and local control. More aggressive measures using current cancer therapies and integration

  6. Adjuvant external beam radiotherapy in the treatment of endometrial cancer (MRC ASTEC and NCIC CTG EN.5 randomised trials): pooled trial results, systematic review, and meta-analysis.

    Science.gov (United States)

    Blake, P; Swart, Ann Marie; Orton, J; Kitchener, H; Whelan, T; Lukka, H; Eisenhauer, E; Bacon, M; Tu, D; Parmar, M K B; Amos, C; Murray, C; Qian, W

    2009-01-10

    Early endometrial cancer with low-risk pathological features can be successfully treated by surgery alone. External beam radiotherapy added to surgery has been investigated in several small trials, which have mainly included women at intermediate risk of recurrence. In these trials, postoperative radiotherapy has been shown to reduce the risk of isolated local recurrence but there is no evidence that it improves recurrence-free or overall survival. We report the findings from the ASTEC and EN.5 trials, which investigated adjuvant external beam radiotherapy in women with early-stage disease and pathological features suggestive of intermediate or high risk of recurrence and death from endometrial cancer. Between July, 1996, and March, 2005, 905 (789 ASTEC, 116 EN.5) women with intermediate-risk or high-risk early-stage disease from 112 centres in seven countries (UK, Canada, Poland, Norway, New Zealand, Australia, USA) were randomly assigned after surgery to observation (453) or to external beam radiotherapy (452). A target dose of 40-46 Gy in 20-25 daily fractions to the pelvis, treating five times a week, was specified. Primary outcome measure was overall survival, and all analyses were by intention to treat. These trials were registered ISRCTN 16571884 (ASTEC) and NCT 00002807 (EN.5). After a median follow-up of 58 months, 135 women (68 observation, 67 external beam radiotherapy) had died. There was no evidence that overall survival with external beam radiotherapy was better than observation, hazard ratio 1.05 (95% CI 0.75-1.48; p=0.77). 5-year overall survival was 84% in both groups. Combining data from ASTEC and EN.5 in a meta-analysis of trials confirmed that there was no benefit in terms of overall survival (hazard ratio 1.04; 95% CI 0.84-1.29) and can reliably exclude an absolute benefit of external beam radiotherapy at 5 years of more than 3%. With brachytherapy used in 53% of women in ASTEC/EN.5, the local recurrence rate in the observation group at 5 years

  7. Impact of External Beam Adjuvant Radiotherapy on Health-Related Quality of Life for Long-Term Survivors of Endometrial Adenocarcinoma: A Population-Based Study

    International Nuclear Information System (INIS)

    Poll-Franse, Lonneke V. van de; Mols, Floortje; Essink-Bot, Marie-Louise; Haartsen, Joke E.; Vingerhoets, Ad J.J.M.; Lybeert, Marnix L.M.; Berg, Hetty A. van den; Coebergh, Jan Willem W.

    2007-01-01

    Purpose: To compare the health-related quality of life (HRQOL) among 5-10-year survivors of Stage I-II endometrial (adeno-)carcinoma (EC) treated with surgery alone or surgery with external beam adjuvant radiotherapy (EBRT) and an age-matched norm population. Methods and Materials: A population-based, cross-sectional survey was conducted by the Eindhoven Cancer Registry. All patients were included who had been diagnosed with EC between 1994 and 1998 (n = 462). Information from the questionnaires returned was linked to data from the Eindhoven Cancer Registry on patient, tumor, and treatment characteristics. Results: Responses were received from 75% of the patients. The analyses were restricted to women with Stage I-II disease at diagnosis, treated with either surgery alone or surgery with adjuvant EBRT, and without recurrent disease or new primary malignancies (n = 264). The patients who had received adjuvant EBRT (n = 80) had had a significantly higher tumor stage and grade at diagnosis (p < 0.0001) and a longer mean time since diagnosis (p = 0.04). Age, number of comorbid diseases, current marital status, nulliparity, education, and occupation were similar for both treatment groups. On multivariate analyses, adjuvant EBRT was independently and negatively associated with the vitality and physical and social well-being scale scores. The HRQOL scores of both treatment groups, however, were similar to those of an age-matched norm population. Conclusion: In general, the HRQOL of EC survivors is good. EC survivors treated with surgery alone had a better HRQOL than women treated with surgery and adjuvant EBRT, although for both groups, the HRQOL was in the range of the norm population

  8. Benefit of Adjuvant Brachytherapy Versus External Beam Radiation for Early Breast Cancer: Impact of Patient Stratification on Breast Preservation

    International Nuclear Information System (INIS)

    Smith, Grace L.; Jiang, Jing; Buchholz, Thomas A.; Xu, Ying; Hoffman, Karen E.; Giordano, Sharon H.; Hunt, Kelly K.; Smith, Benjamin D.

    2014-01-01

    Purpose: Brachytherapy after lumpectomy is an increasingly popular breast cancer treatment, but data concerning its effectiveness are conflicting. Recently proposed “suitability” criteria guiding patient selection for brachytherapy have never been empirically validated. Methods: Using the Surveillance, Epidemiology, and End Results–Medicare linked database, we compared women aged 66 years or older with invasive breast cancer (n=28,718) or ductal carcinoma in situ (n=7229) diagnosed from 2002 to 2007, treated with lumpectomy alone, brachytherapy, or external beam radiation therapy (EBRT). The likelihood of breast preservation, measured by subsequent mastectomy risk, was compared by use of multivariate proportional hazards, further stratified by American Society for Radiation Oncology (ASTRO) brachytherapy suitability groups. We compared 1-year postoperative complications using the χ 2 test and 5-year local toxicities using the log-rank test. Results: For patients with invasive cancer, the 5-year subsequent mastectomy risk was 4.7% after lumpectomy alone (95% confidence interval [CI], 4.1%-5.4%), 2.8% after brachytherapy (95% CI, 1.8%-4.3%), and 1.3% after EBRT (95% CI, 1.1%-1.5%) (P<.001). Compared with lumpectomy alone, brachytherapy achieved a more modest reduction in adjusted risk (hazard ratio [HR], 0.61; 95% CI, 0.40-0.94) than achieved with EBRT (HR, 0.22; 95% CI, 0.18-0.28). Relative risks did not differ when stratified by ASTRO suitability group (P=.84 for interaction), although ASTRO “suitable” patients did show a low absolute subsequent mastectomy risk, with a minimal absolute difference in risk after brachytherapy (1.6%; 95% CI, 0.7%-3.5%) versus EBRT (0.8%; 95% CI, 0.6%-1.1%). For patients with ductal carcinoma in situ, EBRT maintained a reduced risk of subsequent mastectomy (HR, 0.40; 95% CI, 0.28-0.55; P<.001), whereas the small number of patients treated with brachytherapy (n=179) precluded definitive comparison with lumpectomy alone. In

  9. Clinical outcomes of adjuvant external-beam radiotherapy for differentiated thyroid cancer. Results after 874 patient-years of follow-up in the MSDS-trial

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    Biermann, M. [Haukeland University Hospital, Bergen (Norway). Dept. of Radiology; Pixberg, M.K.; Riemann, B.; Schober, O. [Muenster Univ. (Germany). Dept. of Nuclear Medicine; Schuck, A.; Willich, N. [Muenster Univ. (Germany). Dept. of Radiooncology; Heinecke, A. [Muenster Univ. (Germany). Dept. of Biometrics; Schmid, K.W. [University Hospital of Essen, West German Cancer Center (Germany). Inst. of Pathology and Neuropathology; Dralle, H. [Halle-Wittenberg Univ. (Germany). Dept. of General Surgery

    2009-07-01

    Evaluate the clinical benefit of external beam radiotherapy (RTx) for locally invasive thyroid carcinoma with follicular cell differentiation (DTC). The Multicentre Study on Differentiated Thyroid Cancer (MSDS) was planned as a prospective multicenter trial on the benefit of adjuvant RTx in locally invasive DTC (pT4; UICC 1997) with or without lymph node metastases and no known distant metastases. All patients were treated with thyroidectomy, {sup 131}I-therapy, and TSH-suppression and were randomized to receive additional RTx or not. In 4/2003 the trial became a prospective cohort study after only 45 of then 311 patients had consented to randomization. 351 of 422 patients met the trial's inclusion criteria. Age was 48 {+-} 12 years (mean {+-} SD). 25% were men. Tumours were papillary in 90% and follicular in 10%. Of 47 patients randomized or allocated to RTx, 26 actually received RTx. Mean follow-up was 930 days. In an actual treatment analysis, 96% (25/26) of the RTx-patients reached complete remission (CR) vs. 86% in the non-RTx patients. Recurrences occurred in 0 vs. 3 % of patients: 6 reoperated for regional lymph node metastases, 1 tracheal invasion treated with tracheoplasty, 1 local invasion necessitating laryngectomy, 2 distant metastases (1 lung, 1 lung + bone). Serious chronic RTx toxicity occurred in 1/26 patients. The MSDS trial showed low mortality and recurrence rates and a weak benefit of RTx in terms of local control that did however not reach statistical significance. Routine RTx in locally invasive DTC can no longer be recommended. (orig.)

  10. Clinical outcomes of adjuvant external-beam radiotherapy for differentiated thyroid cancer. Results after 874 patient-years of follow-up in the MSDS-trial

    International Nuclear Information System (INIS)

    Biermann, M.; Pixberg, M.K.; Riemann, B.; Schober, O.; Schuck, A.; Willich, N.; Heinecke, A.; Schmid, K.W.; Dralle, H.

    2009-01-01

    Evaluate the clinical benefit of external beam radiotherapy (RTx) for locally invasive thyroid carcinoma with follicular cell differentiation (DTC). The Multicentre Study on Differentiated Thyroid Cancer (MSDS) was planned as a prospective multicenter trial on the benefit of adjuvant RTx in locally invasive DTC (pT4; UICC 1997) with or without lymph node metastases and no known distant metastases. All patients were treated with thyroidectomy, 131 I-therapy, and TSH-suppression and were randomized to receive additional RTx or not. In 4/2003 the trial became a prospective cohort study after only 45 of then 311 patients had consented to randomization. 351 of 422 patients met the trial's inclusion criteria. Age was 48 ± 12 years (mean ± SD). 25% were men. Tumours were papillary in 90% and follicular in 10%. Of 47 patients randomized or allocated to RTx, 26 actually received RTx. Mean follow-up was 930 days. In an actual treatment analysis, 96% (25/26) of the RTx-patients reached complete remission (CR) vs. 86% in the non-RTx patients. Recurrences occurred in 0 vs. 3 % of patients: 6 reoperated for regional lymph node metastases, 1 tracheal invasion treated with tracheoplasty, 1 local invasion necessitating laryngectomy, 2 distant metastases (1 lung, 1 lung + bone). Serious chronic RTx toxicity occurred in 1/26 patients. The MSDS trial showed low mortality and recurrence rates and a weak benefit of RTx in terms of local control that did however not reach statistical significance. Routine RTx in locally invasive DTC can no longer be recommended. (orig.)

  11. 125I implants as an adjuvant to surgery and external beam radiotherapy in the management of locally advanced head and neck cancer

    International Nuclear Information System (INIS)

    Martinez, A.; Goffinet, D.R.; Fee, W.; Goode, R.; Cox, R.S.

    1983-01-01

    125 I seeds either individually placed or inserted into absorbable Vicryl suture carriers were utilized in conjunction with surgery and external beam radiotherapy in an attempt to increase local control rates in patients with advanced oropharyngeal and laryngopharyngeal cancers (T3-T4, N2-N3), massive cervical lymphadenopathy (N3) and an unknown primary site and locally recurrent head and neck cancers. Forty-eight patients were treated with 55 implants. The carotid artery was implanted in 15 patients, while seven patients had seeds inserted into the base of the skull region, and another three patients had implants near cranial nerves. Eighteen of the 48 patients were treated for cure. The actuarial survival at five years in this subgroup was 50%. The overall local control in the head and neck area was 58%. In this group no patients to date have had a local failure in the implanted volume. Seventeen patients with comparable stage of disease treated prior to 1974 with curative intent without 125 I implants were analyzed retrospectively for comparison with the implanted patients. The actuarial survival of these patients was 18% and the overall head and neck control was 21%. These differences are statistically significant at a P value of 0.01 and 0.007, respectively. Seventeen patients received implants for local recurrence. The local control in the head and neck area was 50%; however, the 2.5 year actuarial survival was only 17%. The complication rate was 11% (six of 55 implants). The improved survival, the high local control, and the minimal complication rates in this series makes the intraoperative implantation of 125 I seeds and effective adjunctive treatment to surgery and external beam irradiation

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

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

    2012-02-01

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

  13. Prospective Phase II Study of Brachytherapy Boost as a Component of Neo-Adjuvant Chemotherapy and External Beam Radiation Therapy in Locally Advanced Rectal Cancer

    International Nuclear Information System (INIS)

    EL-SAYED, M.E.; EL-TAHER, Z.H.

    2008-01-01

    The aim of the current study is to assess the response rate and toxicity profile in patients with locally advanced rectal cancer using brachytherapy (BT) boost following external beam radiotherapy (EBRT), concomitant with chemotherapy as a component of the neoadjuvant treatment. Patients and Methods: This is a prospective phase II study of neoadjuvant chemo-radiation therapy for patients with locally advanced rectal cancer who presented to the department of radiation oncology, King Abdul-Aziz University Hospital, Jeddah, Kingdom of Saudi Arabia. Seventeen patients had been included in the study. Radiation therapy was given as: phase I,45 Gy/25 fractions/5 weeks of EBRT, followed by brachytherapy boost (within one week after the end of EBRT) using high dose rate iridium 192 (Ir 192 ) aiming at 800 c Gy given in 2 fractions (each 400 c Gy) separated by 1 week. All patients received the same concomitant chemotherapy in the form of Capecitabine and Oxaliplatin. The clinical and pathological response rates, together with the toxicity profile were assessed. Results: Seventeen patients had been studied; the majority (14; 82%) were males, while 3 only (18%) were females, their mean age was 57.4 years. All patients had low anterior resection (LAR). The clinical response rate, assessed by digital rectal examination ± endoscopy examination 4 weeks after the end of EBRT and BT, revealed that complete clinical response (cCR) was noted in 3 patients (18%), clinical partial response (cPR) in 14 patients (82%); while the pathological response rate was: complete pathological response (pCR) in 8 patients (47%), pathological partial response (pPR) in 9 patients (53%). The toxicity profile showed that grade III radiation proctitis was seen in one patient (6%), grade III dermatitis in 2 (12%), while no patients developed grade III cystitis. For chemotherapy toxicities, three patients (18%) developed grade III nausea and/or vomiting, 2 (12%) developed grade III diarrhea. Conclusion

  14. External proton and Li beams

    International Nuclear Information System (INIS)

    Schuff, Juan A.; Burlon, Alejandro A.; Debray, Mario E.; Kesque, Jose M.; Kreiner, Andres J.; Stoliar, Pablo A.; Naab, Fabian; Ozafran, Mabel J.; Vazquez, Monica E.; Perez de la Hoz, A.; Somacal, Hector; Valda, Alejandro; Canevas, S.; Ruffolo, M.; Tasat, D.R.; Muhlmann, M. C.

    2000-01-01

    In the frame of a feasibility study to introduce proton therapy in Argentina in a collaborative agreement between the Physics and Radiobiology Departments of the National Atomic Energy Commission or Argentina and the Centre de Protontherapie de Orsay, France, external proton and Li beams were produced at the TANDAR accelerator in Buenos Aires. The specific aim of this work was to start radiobiology studies on cell cultures and small laboratory animals. In particular we seek to determine here the relative biological effectiveness, RBE, for proton and Li beams as a function of energy for different tumor and normal cell lines. The 24 MeV proton beam was diffused using a 25 μm gold foil and extracted through a Kapton window to obtain a homogeneous field (constant to 95%) of about 7 cm in diameter. Measurements were carried out with quasi-monoenergetic beams (of 20.2 ± 0.07 MeV, 2.9 ± 0.10 MeV y 1.5 ± 0.1 MeV for protons and 21.4 ± 0.4 MeV for Lithium). Proton fluence and Bragg peaks were measured. The dose delivered in each case was monitored on-line with a calibrated transmission ionization chamber. Three cell lines PDV, PDVC 57 and V 79 (as a reference) were irradiated with γ-rays, proton and lithium beams with linear energy transfer (LET) from 2 to 100 keV/μm. RBE values in the range of 1.2-5.9 were obtained. In addition preliminary studies on chromosomal aberrations and viability of alveolar macrophages were carried out. (author)

  15. External Beam Radiation in Differentiated Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Salem Billan

    2016-01-01

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

  16. External Beam Radiation Therapy for Cancer

    Science.gov (United States)

    External beam radiation therapy is used to treat many types of cancer. it is a local treatment, where a machine aims radiation at your cancer. Learn more about different types of external beam radiation therapy, and what to expect if you're receiving treatment.

  17. Conventional external irradiation alone as adjuvant treatment in resectable pancreatic cancer; Results of a prospective study

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    Bosset, J.F.; Pavy, J.J.; Gillet, M.; Mantuon, G.; Pelissier, E.; Schraub, S. (Centre Hospitalier Universitaire, 25 - Besancon (France))

    1992-07-01

    Between 1/85 and 1/90, 14 consecutive patients were entered into a prospective study of conventional adjuvant post-operative external beam radiotherapy after complete resection for a pancreatic adeno-carcinoma. The surgical procedure was a Whipple resection in 9 patients, a distal pancrea-tectomy in 1 patient. There were 3 T[sub 1b], 8 T[sub 2] and 3 T[sub 3] tumors (UICC 1987); nodal involvement was present in 5 cases. The radiotherapy was delivered using a 4-field box technique with a 23 x MV photon beam. All patients received a total dose of 54 Gy to the tumor bed. The mean treated volume was 900 cm[sup 3]. Acute toxicities consisted mainly of weight loss (mean: 2 kg). Two patients had a grade 2 diarrhea and 2 patients a grade 2 gastritis. Late effects were minimal and only observed in 2 patients. The overall loco-regional recurrence (LR) rate was 50%. The median disease-free survival was 12 months, and the median survival was 23 months. This post-operative conventional radiotherapy treatment gives results that are comparable to the results of GITSG-adjuvant study using a combination of split-course radiotherapy and 5-fluorouracil (5-FU). (author). 46 refs.; 1 fig.; 1 tab.

  18. Conventional external irradiation alone as adjuvant treatment in resectable pancreatic cancer

    International Nuclear Information System (INIS)

    Bosset, J.F.; Pavy, J.J.; Gillet, M.; Mantuon, G.; Pelissier, E.; Schraub, S.

    1992-01-01

    Between 1/85 and 1/90, 14 consecutive patients were entered into a prospective study of conventional adjuvant post-operative external beam radiotherapy after complete resection for a pancreatic adeno-carcinoma. The surgical procedure was a Whipple resection in 9 patients, a distal pancrea-tectomy in 1 patient. There were 3 T 1b , 8 T 2 and 3 T 3 tumors (UICC 1987); nodal involvement was present in 5 cases. The radiotherapy was delivered using a 4-field box technique with a 23 x MV photon beam. All patients received a total dose of 54 Gy to the tumor bed. The mean treated volume was 900 cm 3 . Acute toxicities consisted mainly of weight loss (mean: 2 kg). Two patients had a grade 2 diarrhea and 2 patients a grade 2 gastritis. Late effects were minimal and only observed in 2 patients. The overall loco-regional recurrence (LR) rate was 50%. The median disease-free survival was 12 months, and the median survival was 23 months. This post-operative conventional radiotherapy treatment gives results that are comparable to the results of GITSG-adjuvant study using a combination of split-course radiotherapy and 5-fluorouracil (5-FU). (author). 46 refs.; 1 fig.; 1 tab

  19. Beam-beam effects under the influence of external noise

    International Nuclear Information System (INIS)

    Ohmi, K

    2014-01-01

    Fast external noise, which gives fluctuation into the beam orbit, is discussed in connection with beam-beam effects. Phase noise from crab cavities and detection devices (position monitor) and kicker noise from the bunch by bunch feedback system are the sources. Beam-beam collisions with fast orbit fluctuations with turn by turn or multi-turn correlations, cause emittance growth and luminosity degradation. We discuss the tolerance of the noise amplitude for LHC and HL-LHC

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

    LENUS (Irish Health Repository)

    Daly, Patricia E

    2012-07-01

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

  1. External beam radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Forman, Jeffrey D.

    1996-01-01

    Purpose/Objectives: The intent of this course is to review the issues involved in the management of non-metastatic adenocarcinoma of the prostate. -- The value of pre-treatment prognostic factors including stage, grade and PSA value will be presented, and their value in determining therapeutic strategies will be discussed. -- Controversies involving the simulation process and treatment design will be presented. The value of CT scanning, Beams-Eye View, 3-D planning, intravesicle, intraurethral and rectal contrast will be presented. The significance of prostate and patient movement and strategies for dealing with them will be presented. -- The management of low stage, low to intermediate grade prostate cancer will be discussed. The dose, volume and timing of irradiation will be discussed as will the role of neo-adjuvant hormonal therapy, neutron irradiation and brachytherapy. The current status of radical prostatectomy and cryotherapy will be summarized. Treatment of locally advanced, poorly differentiated prostate cancer will be presented including a discussion of neo-adjuvant and adjuvant hormones, dose-escalation and neutron irradiation. -- Strategies for post-radiation failures will be presented including data on cryotherapy, salvage prostatectomy and hormonal therapy (immediate, delayed and/or intermittent). New areas for investigation will be reviewed. -- The management of patients post prostatectomy will be reviewed. Data on adjuvant radiation and therapeutic radiation for biochemical or clinically relapsed patients will be presented. This course hopes to present a realistic and pragmatic overview for treating patients with non-metastatic prostatic cancer

  2. Adjuvant Ab Interno Tumor Treatment After Proton Beam Irradiation.

    Science.gov (United States)

    Seibel, Ira; Riechardt, Aline I; Heufelder, Jens; Cordini, Dino; Joussen, Antonia M

    2017-06-01

    This study was performed to show long-term outcomes concerning globe preservation in uveal melanoma patients after proton beam therapy with the main focus on outcomes according to different adjuvant ab interno surgical procedures. Retrospective cohort study. All patients treated with primary proton beam therapy for choroidal or ciliary body melanoma between June 1998 and June 2015 were included. A total of 2499 patients underwent primary proton beam therapy, with local tumor control and globe preservation rates of 95.9% and 94.8% after 5 years, respectively. A total of 110 (4.4%) patients required secondary enucleation. Unresponsive neovascular glaucoma was the leading cause of secondary enucleation in 78 of the 2499 patients (3.1%). The 5-year enucleation-free survival rate was 94.8% in the endoresection group, 94.3% in the endodrainage group, and 93.5% in the comparator group. The log-rank test showed P = .014 (comparator group vs endoresection group) and P = .06 (comparator group vs endodrainage-vitrectomy group). Patients treated with endoresection or endodrainage-vitrectomy developed less radiation retinopathy (30.5% and 37.4% after 5 years, P = .001 and P = .048 [Kaplan-Meier], respectively) and less neovascular glaucoma (11.6% and 21.3% after 5 years, P = .001 and P = .01 [Kaplan-Meier], respectively) compared with the comparator group (52.3% radiation retinopathy and 57.8% neovascular glaucoma after 5 years). This study suggests that in larger tumors the enucleation and neovascular glaucoma rates might be reduced by adjuvant surgical procedures. Although endoresection is the most promising adjuvant treatment option, the endodrainage-vitrectomy is recommended in patients who are ineligible for endoresection. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Beam intensity monitoring for the external proton beam at LAMPF

    International Nuclear Information System (INIS)

    Barrett, R.J.; Anderson, B.D.; Willard, H.B.; Anderson, A.N.; Jarmie, N.

    1975-07-01

    Three different intensity monitors were tested in the external proton beam at LAMPF, and together cover the entire range of beam currents available. A 800 kg Faraday cup was installed and used to measure the absolute intensity to better than 1 percent for beam currents up to several nanoamperes. A high gain ion chamber was used as part of the calibration procedure for the Faraday cup, and was found to be useful when monitoring very small beam intensities, being reliable down to the few picoampere level. A secondary emission monitor was also tested, calibrated, and found to be trustworthy only for beams of greater than 50 pA intensity. (auth)

  4. CONTINOUS EXTRACTED BEAM IN THE AGS FAST EXTERNAL BEAM LINE

    International Nuclear Information System (INIS)

    GLENN, J.W.; TSOUPAS, N.; BROWN, K.A.; BIRYUKOV, V.M.

    2001-01-01

    A method to split off a few percent of the 6 x 10 13 AGS beam delivered to the Slow External Beam (SEB) lines and send it down the Fast External Beam line (FEB) has been developed. The mission is to feed a counter experiment off the FEB that directly measures the neutrino mass using the muon storage ring. The use of normal thin septum splitters would have an excessive loss overhead and been optically difficult. The AGS Slow Extraction uses a third integer resonance with sextuple strength so the resonance width is a few percent of the beam width. This results in a low density tail which will be clipped by a bent crystal and deflected into the FEB channel. This clipping off of the tail should reduce losses in the SEB transport line. Details of modeled orbits, particle distribution and extraction trajectories into and out off the crystal will be given

  5. A Comparison Between Low-Dose-Rate Brachytherapy With or Without Androgen Deprivation, External Beam Radiation Therapy With or Without Androgen Deprivation, and Radical Prostatectomy With or Without Adjuvant or Salvage Radiation Therapy for High-Risk Prostate Cancer

    International Nuclear Information System (INIS)

    Ciezki, Jay P.; Weller, Michael; Reddy, Chandana A.; Kittel, Jeffrey; Singh, Harguneet; Tendulkar, Rahul; Stephans, Kevin L.; Ulchaker, James; Angermeier, Kenneth; Stephenson, Andrew; Campbell, Steven; Haber, Georges-Pascal; Klein, Eric A.

    2017-01-01

    Purpose: We compare the efficacy and toxicity among the 3 major modalities available used to treat high-risk prostate cancer (HRCaP). Methods and Materials: From 1996 to 2012, 2557 HRCaP patients were treated: 734 received external beam radiation therapy (EBRT) with or without androgen deprivation therapy (ADT), 515 received low-dose-rate prostate brachytherapy (LDR) with or without ADT, and 1308 received radical prostatectomy (RP) with or without EBRT. Biochemical relapse-free survival (bRFS), clinical relapse-free survival (cRFS), and prostate cancer–specific mortality (PCSM) were assessed. Toxicity was assessed using the Common Terminology Criteria for Adverse Events, version 4.03. The log-rank test compared bRFS and cRFS among the modalities, and Cox regression identified factors associated with bRFS and cRFS. Gray's test compared differences in late toxicity and PSCM among the modalities. Competing risk regression identified factors associated with PCSM. Results: The median follow-up time and age were 63.5 months and 65 years, respectively. The bRFS at 5 and 10 years, respectively, was 74% and 53% for EBRT, 74% and 52% for LDR, and 65% and 47% for RP (P=.0001). The cRFS at 5 and 10 years, respectively, was 85% and 73% for EBRT, 90% and 76% for LDR, and 89% and 75% for RP (P=.121). The PCSM at 5 and 10 years, respectively, was 5.3% and 11.2% for EBRT, 3.2% and 3.6% for LDR, and 2.8% and 6.8% for RP (P=.0004). The 10-year cumulative incidence of ≥grade 3 genitourinary toxicity was 8.1% for EBRT, 7.2% for LDR, and 16.4% for RP (P<.0001). The 10-year cumulative incidence of ≥grade 3 gastrointestinal toxicity was 4.6% for EBRT, 1.1% for LDR, and 1.0% for RP (P<.0001). Conclusion: HRCaP treated with EBRT, LDR, or RP yields efficacy showing better bRFS for LDR and EBRT relative to RP, equivalence for cRFS, and a PCSM advantage of LDR and RP over EBRT. The toxicity is lowest for LDR.

  6. A Comparison Between Low-Dose-Rate Brachytherapy With or Without Androgen Deprivation, External Beam Radiation Therapy With or Without Androgen Deprivation, and Radical Prostatectomy With or Without Adjuvant or Salvage Radiation Therapy for High-Risk Prostate Cancer.

    Science.gov (United States)

    Ciezki, Jay P; Weller, Michael; Reddy, Chandana A; Kittel, Jeffrey; Singh, Harguneet; Tendulkar, Rahul; Stephans, Kevin L; Ulchaker, James; Angermeier, Kenneth; Stephenson, Andrew; Campbell, Steven; Haber, Georges-Pascal; Klein, Eric A

    2017-04-01

    We compare the efficacy and toxicity among the 3 major modalities available used to treat high-risk prostate cancer (HRCaP). From 1996 to 2012, 2557 HRCaP patients were treated: 734 received external beam radiation therapy (EBRT) with or without androgen deprivation therapy (ADT), 515 received low-dose-rate prostate brachytherapy (LDR) with or without ADT, and 1308 received radical prostatectomy (RP) with or without EBRT. Biochemical relapse-free survival (bRFS), clinical relapse-free survival (cRFS), and prostate cancer-specific mortality (PCSM) were assessed. Toxicity was assessed using the Common Terminology Criteria for Adverse Events, version 4.03. The log-rank test compared bRFS and cRFS among the modalities, and Cox regression identified factors associated with bRFS and cRFS. Gray's test compared differences in late toxicity and PSCM among the modalities. Competing risk regression identified factors associated with PCSM. The median follow-up time and age were 63.5 months and 65 years, respectively. The bRFS at 5 and 10 years, respectively, was 74% and 53% for EBRT, 74% and 52% for LDR, and 65% and 47% for RP (P=.0001). The cRFS at 5 and 10 years, respectively, was 85% and 73% for EBRT, 90% and 76% for LDR, and 89% and 75% for RP (P=.121). The PCSM at 5 and 10 years, respectively, was 5.3% and 11.2% for EBRT, 3.2% and 3.6% for LDR, and 2.8% and 6.8% for RP (P=.0004). The 10-year cumulative incidence of ≥grade 3 genitourinary toxicity was 8.1% for EBRT, 7.2% for LDR, and 16.4% for RP (PLDR, and 1.0% for RP (PLDR, or RP yields efficacy showing better bRFS for LDR and EBRT relative to RP, equivalence for cRFS, and a PCSM advantage of LDR and RP over EBRT. The toxicity is lowest for LDR. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. A Comparison Between Low-Dose-Rate Brachytherapy With or Without Androgen Deprivation, External Beam Radiation Therapy With or Without Androgen Deprivation, and Radical Prostatectomy With or Without Adjuvant or Salvage Radiation Therapy for High-Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ciezki, Jay P., E-mail: ciezkij@ccf.org [Taussig Cancer Institute, Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio (United States); Weller, Michael; Reddy, Chandana A.; Kittel, Jeffrey; Singh, Harguneet; Tendulkar, Rahul; Stephans, Kevin L. [Taussig Cancer Institute, Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio (United States); Ulchaker, James; Angermeier, Kenneth; Stephenson, Andrew; Campbell, Steven; Haber, Georges-Pascal; Klein, Eric A. [Glickman Urological and Kidney Institute, Department of Urology, Cleveland Clinic, Cleveland, Ohio (United States)

    2017-04-01

    Purpose: We compare the efficacy and toxicity among the 3 major modalities available used to treat high-risk prostate cancer (HRCaP). Methods and Materials: From 1996 to 2012, 2557 HRCaP patients were treated: 734 received external beam radiation therapy (EBRT) with or without androgen deprivation therapy (ADT), 515 received low-dose-rate prostate brachytherapy (LDR) with or without ADT, and 1308 received radical prostatectomy (RP) with or without EBRT. Biochemical relapse-free survival (bRFS), clinical relapse-free survival (cRFS), and prostate cancer–specific mortality (PCSM) were assessed. Toxicity was assessed using the Common Terminology Criteria for Adverse Events, version 4.03. The log-rank test compared bRFS and cRFS among the modalities, and Cox regression identified factors associated with bRFS and cRFS. Gray's test compared differences in late toxicity and PSCM among the modalities. Competing risk regression identified factors associated with PCSM. Results: The median follow-up time and age were 63.5 months and 65 years, respectively. The bRFS at 5 and 10 years, respectively, was 74% and 53% for EBRT, 74% and 52% for LDR, and 65% and 47% for RP (P=.0001). The cRFS at 5 and 10 years, respectively, was 85% and 73% for EBRT, 90% and 76% for LDR, and 89% and 75% for RP (P=.121). The PCSM at 5 and 10 years, respectively, was 5.3% and 11.2% for EBRT, 3.2% and 3.6% for LDR, and 2.8% and 6.8% for RP (P=.0004). The 10-year cumulative incidence of ≥grade 3 genitourinary toxicity was 8.1% for EBRT, 7.2% for LDR, and 16.4% for RP (P<.0001). The 10-year cumulative incidence of ≥grade 3 gastrointestinal toxicity was 4.6% for EBRT, 1.1% for LDR, and 1.0% for RP (P<.0001). Conclusion: HRCaP treated with EBRT, LDR, or RP yields efficacy showing better bRFS for LDR and EBRT relative to RP, equivalence for cRFS, and a PCSM advantage of LDR and RP over EBRT. The toxicity is lowest for LDR.

  8. External beam radiotherapy for unresectable pancreatic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kagami, Yoshikazu; Nishio, Masamichi; Narimatsu, Naoto; Ogawa, Hajime; Betsuyaku, Takashi; Hirata, Kouji; Ikeda, Shigeyuki (Sapporo National Hospital (Japan). Hokkaido Cancer Center)

    1992-04-01

    Between 1980 to 1989, 24 patients with unresectable pancreatic cancer (10 with localized tumor alone and 14 with distant metastases) have been treated with external beam radiation at Sapporo National Hospital, Hokkaido Cancer Center. Response rate of pancreatic tumor treated with external beam radiation was 33.3% (7/21) with no complete response. Median survival time of the patients with localized tumor was 10 months and that of the patients with distant metastases was 3 months. Relief of pain occurred in 92.9% (12/13) of patients having pain due to pancreatic tumor and in 75% (3/4) of patients having pain due to bone metastases. Major complication was gastric ulcer which developed in 5 patients of 21 patients given stomach irradiation. We concluded that unresectable pancreatic cancer would be frequently indicated for radiotherapy. (author).

  9. Prostate-specific antigen (Pasa) bounce and other fluctuations: Which biochemical relapse definition is least prone to PSA false calls? An analysis of 2030 men treated for prostate cancer with external beam or brachytherapy with or without adjuvant androgen deprivation therapy

    International Nuclear Information System (INIS)

    Pickles, Tom

    2006-01-01

    Purpose: To determine the false call (FC) rate for prostate-specific antigen (PSA) relapse according to nine different PSA relapse definitions after a PSA fluctuation (bounce) has occurred after external beam radiation therapy (EBRT) or brachytherapy, with or without adjuvant androgen deprivation therapy. Methods and Materials: An analysis of a prospective database of 2030 patients was conducted. Prostate-specific antigen relapse was scored according to the American Society for Therapeutic Radiology and Oncology (ASTRO), Vancouver, threshold + n, and nadir + n definitions for the complete data set and then compared against a truncated data set, with data subsequent to the height of the bounce deleted. The FC rate was calculated for each definition. Results: The bounce rate, with this very liberal definition of bounce, was 58% with EBRT and 84% with brachytherapy. The FC rate was lowest with nadir + 2 and + 3 definitions (2.2% and 1.6%, respectively) and greatest with low-threshold and ASTRO definitions (32% and 18%, respectively). The ASTRO definition was particularly susceptible to FC when androgen deprivation therapy was used with radiation (24%). Discussion: New definitions of biochemical non-evidence of disease that are more robust than the ASTRO definition have been identified. Those with the least FC rates are the nadir + 2 and nadir + 3 definitions, both of which are being considered to replace the ASTRO definition by the 2005 meeting of the Radiation Therapy Oncology Group-ASTRO consensus panel

  10. Proton external beam in the TANDAR Accelerator

    International Nuclear Information System (INIS)

    Rey, R.; Schuff, J.A.; Perez de la Hoz, A.; Debray, M.E.; Hojman, D.; Kreiner, A.J.; Kesque, J.M.; Saint-Martin, G.; Oppezzo, O.; Bernaola, O.A.; Molinari, B.L.; Duran, H.A.; Policastro, L.; Palmieri, M.; Ibanez, J.; Stoliar, P.; Mazal, A.; Caraballo, M.E.; Burlon, A.; Cardona, M.A.; Vazquez, M.E.; Salfity, M.F.; Ozafran, M.J.; Naab, F.; Levinton, G.; Davidson, M.; Buhler, M.

    1998-01-01

    An external proton beam has been obtained in the TANDAR accelerator with radiological and biomedical purposes. The protons have excellent physical properties for their use in radiotherapy allowing a very good accuracy in the dose spatial distribution inside the tissue so in the side direction as in depth owing to the presence of Bragg curve. The advantage of the accuracy in the dose localization with proton therapy is good documented (M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983); M.R. Raju, Rad. Res. 145, 391 (1996)). It was obtained external proton beams with energies between 15-25 MeV, currents between 2-10 p A and a uniform transversal sections of 40 mm 2 approximately. It was realized dosimetric evaluations with CR39 and Makrofol foliation. The irradiations over biological material contained experiences In vivo with laboratory animals, cellular and bacterial crops. It was fixed the optimal conditions of position and immobilization of the Wistar rats breeding for the In vivo studies. It was chosen dilutions and sowing techniques adequate for the exposition at the cellular and bacterial crops beam. (Author)

  11. Guide for External Beam Radiotherapy. Procedures 2007

    International Nuclear Information System (INIS)

    Ardiet, Jean-Michel; Bourhis, Jean; Eschwege, Francois; Gerard, Jean-Pierre; Martin, Philippe; Mazeron, Jean-Jacques; Barillot, Isabelle; Bey, Pierre; Cosset, Jean-Marc; Thomas, Olivier; Bolla, Michel; Bourguignon, Michel; Godet, Jean-Luc; Krembel, David; Valero, Marc; Bara, Christine; Beauvais-March, Helene; Derreumaux, Sylvie; Vidal, Jean-Pierre; Drouard, Jean; Sarrazin, Thierry; Lindecker-Cournil, Valerie; Robin, Sun Hee Lee; Thevenet, Nicolas; Depenweiller, Christian; Le Tallec, Philippe; Ortholan, Cecile; Aimone, Nicole; Baldeschi, Carine; Cantelli, Andree; Estivalet, Stephane; Le Prince, Cyrille; QUERO, Laurent; Costa, Andre; Gerard, Jean-Pierre; Ardiet, Jean-Michel; Bensadoun, Rene-Jean; Bourhis, Jean; Calais, Gilles; Lartigau, Eric; Ginot, Aurelie; Girard, Nicolas; Mornex, Francoise; Bolla, Michel; Chauvet, Bruno; Maingon, Philippe; Martin, Etienne; Azria, David; Gerard, Jean-Pierre; Grehange, Gilles; Hennequin, Christophe; Peiffert, Didier; Toledano, Alain; Belkacemi, Yazid; Courdi, Adel; Belliere, Aurelie; Peignaux, Karine; Mahe, Marc; Bondiau, Pierre-Yves; Kantor, Guy; Lepechoux, Cecile; Carrie, Christian; Claude, Line

    2007-01-01

    In order to optimize quality and security in the delivery of radiation treatment, the French SFRO (Societe francaise de radiotherapie oncologique) is publishing a Guide for Radiotherapy. This guide is realized according to the HAS (Haute Autorite de sante) methodology of 'structured experts consensus'. This document is made of two parts: a general description of external beam radiation therapy and chapters describing the technical procedures of the main tumors to be irradiated (24). For each procedure, a special attention is given to dose constraints in the organs at risk. This guide will be regularly updated

  12. Internal hemipelvectomy with intraoperative and external beam radiotherapy in the limb-sparing treatment of a pelvic girdle chondrosarcoma

    NARCIS (Netherlands)

    Hoekstra, HJ; Szabo, BG

    The case of a patient with an extensive pelvic girdle chondrosarcoma treated with internal hemipelvectomy and intraoperative radiotherapy, followed by adjuvant high-dose external beam radiotherapy, with a successful attempt in achieving long-term local tumor control and limb-sparing treatment is

  13. Charge collection in an external proton beam

    International Nuclear Information System (INIS)

    Wookey, C.W.; Somswasdi, B.; Rouse, J.L.

    1982-01-01

    Results from the measurement of the stability of charge collected from the target and exit foil, or as alternatives, the γ-ray or backscattered proton counts from the exit foil and the Ar X-ray counts from the air path in an external proton beam are presented. These results show that comparative analysis of material mounted in air is reliable, using either the collected charge or the γ-ray counts as the normalizing factor, if there are no earthed objects in close geometry. The backscattered proton counts can also be used, but not the Ar X-ray counts, unless the current is stabilized. The electrical or thermal conductivity of the target and the target to exit foil separation do not affect the proportionality of the collected charge and the γ-ray counts to the charge incident on the target

  14. Elemental analysis with external-beam PIXE

    Science.gov (United States)

    Lin, E. K.; Wang, C. W.; Teng, P. K.; Huang, Y. M.; Chen, C. Y.

    1992-05-01

    A beamline system and experimental setup has been established for elemental analysis using PIXE with an external beam. Experiments for the study of the elemental composition of ancient Chinese potsherds (the Min and Ching ages) were performed. Continuum X-ray spectra from the samples bombarded by 3 MeV protons have been measured with a Si(Li) detector. From the analysis of PIXE data, the concentration of the main elements (Al, Si, K, and Ca) and of more than ten trace elements in the matrices and glazed surfaces were determined. Results for two different potsherds are presented, and those obtained from the glaze colorants are compared with the results of measurements on a Ching blue-and-white porcelain vase.

  15. In vivo dosimetry in external beam radiotherapy

    International Nuclear Information System (INIS)

    Mijnheer, Ben; Beddar, Sam; Izewska, Joanna; Reft, Chester

    2013-01-01

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors’ opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks

  16. External beam PIXE analysis of painting

    International Nuclear Information System (INIS)

    Pascholati, Paulo R.; Rizzutto, Marcia A.; Barbosa, Marcel D.L.; Albuquerque, Cindy

    2005-01-01

    The preservation and conservation of mankind cultural heritage has become an important issue worldwide. Non-destructive analytical techniques are suitable, for example, to analyze precious and unique objects of art and archaeology. Among those techniques Particle Induced X-Ray Emission (PIXE) has good advantage to identify elemental composition present in these kinds of objects. The Laboratorio de Analise de Materiais por Feixes Ionicos-LAMFI of the Institute of Physics of the University of Sao Paulo has been installed an external beam facility for PIXE analysis. This new setup is being used for the analysis of archaeological pottery artifacts, paintings and biological tissues (teeth and bones), which are not compatible with the high vacuum of the regular PIXE target chamber. In addition most art and archaeological objects are too large for the evacuated analysis chamber. Applications of this facility will be presented in the analysis of one painting of the beginning of the last century. The chemical elements identified in the painting were Ca, Ti, Cr, Cu, Fe, Zn, Pb and Ba. The PIXE measurements were done non-destructively and no visible damage was observed on the irradiated object. (author)

  17. In vivo dosimetry in external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mijnheer, Ben [Department of Radiation Oncology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam 1066 CX (Netherlands); Beddar, Sam [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Izewska, Joanna [Division of Human Health, International Atomic Energy Agency, Vienna 1400 (Austria); Reft, Chester [Department of Radiation and Cellular Oncology, University of Chicago Medical Center, Chicago, Illinois 60637 (United States)

    2013-07-15

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  18. External beam radiotherapy for rectal adenocarcinoma

    International Nuclear Information System (INIS)

    Taylor, R.E.; Kerr, G.R.; Arnott, S.J.

    1987-01-01

    A series of 243 patients with adenocarcinoma of the rectum treated with radiotherapy is presented. Radiotherapy was combined with 5-fluorouracil, or given alone. Seventy-four patients were treated with radical external beam radiotherapy for recurrent or inoperable rectal adenocarcinoma. One hundred and forty-five patients with advanced pelvic tumours or metastases were treated with palliative pelvic radiotherapy. Twenty-four patients with small-volume residual pelvic tumour or who were felt to be at high risk of pelvic recurrence following radical resection received postoperative radiotherapy. Complete tumour regression was seen in 38% of radically treated patients, and 24% of palliatively treated patients. Partial regression was observed in 56% of radically treated patients, and 58% of palliatively treated patients. Long-term local tumour control was more commonly observed for small tumours (< 5 cm diameter). Fifty-eight % of patients treated with postoperative radiotherapy remained free of local recurrence. Survival was significantly better with small tumours. The addition of 5FU did not appear to improve survival or tumour control. (author)

  19. 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

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

    International Nuclear Information System (INIS)

    1999-01-01

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

  1. External Beam Radiotherapy for Colon Cancer: Patterns of Care

    International Nuclear Information System (INIS)

    Dunn, Emily F.; Kozak, Kevin R.; Moody, John S.

    2010-01-01

    Purpose: Despite its common and well characterized use in other gastrointestinal malignancies, little is known about radiotherapy (RT) use in nonmetastatic colon cancer in the United States. To address the paucity of data regarding RT use in colon cancer management, we examined the RT patterns of care in this patient population. Methods and Materials: Patients with nonmetastatic colon cancer, diagnosed between 1988 and 2005, were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate methods were used to identify factors associated with RT use. Results: On univariate analysis, tumor location, age, sex, race, T stage, N stage, and geographic location were each associated with differences in RT use (all p < 0.01). In general, younger patients, male patients, and patients with more advanced disease were more likely to receive RT. On multivariate analysis, tumor location, age, gender, T and N stage, time of diagnosis and geographic location were significantly associated with RT use (all p < 0.001). Race, however, was not associated with RT use. On multivariate analysis, patients diagnosed in 1988 were 2.5 times more likely to receive RT than those diagnosed in 2005 (p = 0.001). Temporal changes in RT use reflect a responsiveness to evolving evidence related to the therapeutic benefits of adjuvant RT. Conclusions: External beam RT is infrequently used for colon cancer, and its use varies according to patient and tumor characteristics. RT use has declined markedly since the late 1980s; however, it continues to be used for nonmetastatic disease in a highly individualized manner.

  2. Anesthesia for pediatric external beam radiation therapy

    International Nuclear Information System (INIS)

    Fortney, Jennifer T.; Halperin, Edward C.; Hertz, Caryn M.; Schulman, Scott R.

    1999-01-01

    Background: For very young patients, anesthesia is often required for radiotherapy. This results in multiple exposures to anesthetic agents over a short period of time. We report a consecutive series of children anesthetized for external beam radiation therapy (EBRT). Methods: Five hundred twelve children ≤ 16 years old received EBRT from January 1983 to February 1996. Patient demographics, diagnosis, anesthesia techniques, monitoring, airway management, complications, and outcome were recorded for the patients requiring anesthesia. Results: One hundred twenty-three of the 512 children (24%) required 141 courses of EBRT with anesthesia. Anesthetized patients ranged in age from 20 days to 11 years (mean 2.6 ± 1.8 ). The frequency of a child receiving EBRT and requiring anesthesia by age cohort was: ≤ 1 year (96%), 1-2 years (93%), 2-3 years (80%), 3-4 years (51%), 4-5 years (36%), 5-6 years (13%), 6-7 years (11%), and 7-16 years (0.7%). Diagnoses included: primary CNS tumor (28%), retinoblastoma (27%), neuroblastoma (20%), acute leukemia (9%), rhabdomyosarcoma (6%), and Wilms' tumor (4%). Sixty-three percent of the patients had been exposed to chemotherapy prior to EBRT. The mean number of anesthesia sessions per patient was 22 ± 16. Seventy-eight percent of the treatment courses were once daily and 22% were twice daily. Anesthesia techniques included: short-acting barbiturate induction + inhalation maintenance (21%), inhalation only (20%), ketamine (19%), propofol only (12%), propofol induction + inhalation maintenance (7%), ketamine induction + inhalation maintenance (6%), ketamine or short-acting barbiturate induction + inhalation maintenance (6%). Monitoring techniques included: EKG (95%), O 2 saturation (93%), fraction of inspired O 2 (57%), and end-tidal CO 2 (55%). Sixty-four percent of patients had central venous access. Eleven of the 74 children with a central line developed sepsis (15%): 6 of the 11 were anesthetized with propofol (55%), 4 with a

  3. Shear behavior of concrete beams externally prestressed with Parafil ropes

    Directory of Open Access Journals (Sweden)

    A.H. Ghallab

    2013-03-01

    Full Text Available Although extensive work has been carried out investigating the use of external prestressing system for flexural strengthening, a few studies regarding the shear behavior of externally prestressed beams can be found. Five beams, four of them were externally strengthened using Parafil rope, were loaded up to failure to investigate the effect of shear span/depth ratio, external prestressing force and concrete strength on their shear behavior. Test results showed that the shear span to depth ratio has a significant effect on both the shear strength and failure mode of the strengthened beams and the presence of external prestressing force increased the ultimate load of the tested beams by about 75%. Equations proposed by different codes for both the conventional reinforced concrete beams and for ordinary prestressed beams were used to evaluate the obtained experimental results. In general, codes equations showed a high level of conservatism in predicting the shear strength of the beams. Also, using the full strength rather than half of the concrete shear strength in the Egyptian code PC-method improves the accuracy of the calculated ultimate shear strength.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Cesare H. [Department of Mechanical Engineering and Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Naczynski, Dominik J.; Yu, Shu-Jung S.; Xing, Lei, E-mail: lei@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California 94305 (United States)

    2015-01-15

    Purpose: To characterize the performance of a novel radiation therapy monitoring technique that utilizes a flexible scintillating film, common optical detectors, and image processing algorithms for real-time beam visualization (RT-BV). Methods: Scintillating films were formed by mixing Gd{sub 2}O{sub 2}S:Tb (GOS) with silicone and casting the mixture at room temperature. The films were placed in the path of therapeutic beams generated by medical linear accelerators (LINAC). The emitted light was subsequently captured using a CMOS digital camera. Image processing algorithms were used to extract the intensity, shape, and location of the radiation field at various beam energies, dose rates, and collimator locations. The measurement results were compared with known collimator settings to validate the performance of the imaging system. Results: The RT-BV system achieved a sufficient contrast-to-noise ratio to enable real-time monitoring of the LINAC beam at 20 fps with normal ambient lighting in the LINAC room. The RT-BV system successfully identified collimator movements with sub-millimeter resolution. Conclusions: The RT-BV system is capable of localizing radiation therapy beams with sub-millimeter precision and tracking beam movement at video-rate exposure.

  5. A comparison of protocols for external beam radiotherapy beam calibrations

    International Nuclear Information System (INIS)

    Saeed Al-Ahbabi, Salma; Bradley, D.A.; Beyomi, M.; Alkatib, Z.; Adhaheri, S.; Darmaki, M.; Nisbet, A.

    2012-01-01

    A number of codes of practice (CoP) for electron and photon radiotherapy beam dosimetry are currently in use. Comparison is made of the more widely used of these, specifically those of the International Atomic Energy Agency (IAEA TRS-398), the American Association of Physicists in Medicine (AAPM TG-51) and the Institute of Physics and Engineering in Medicine (IPEM 2003). All are based on calibration of ionization chambers in terms of absorbed dose to water, each seeking to reduce uncertainty in delivered dose, providing an even stronger system of primary standards than previous air-kerma based approaches. They also provide a firm, traceable and straight-forward formalism. Included in making dose assessments for the three CoP are calibration coefficients for a range of beam quality indices. Measurements have been performed using clinical photon and electron beams, the absorbed dose to water being obtained following the recommendations given by each code. Electron beam comparisons have been carried out using measurements for electron beams of nominal energies 6, 9, 12, 16 and 20 MeV. Comparisons were also carried out for photon beams of nominal energies 6 and 18 MV. For photon beams use was made of NE2571 cylindrical graphite walled ionization chambers, cross-calibrated against an NE2611 Secondary Standard; for electron beams, PTW Markus and NACP-02 plane-parallel chambers were used. Irradiations were made using Varian 600C/2100C linacs, supported by water tanks and Virtual Water™ phantoms. The absorbed doses for photon and electron beams obtained following these CoP are all in good agreement, with deviations of less than 2%. A number of studies have been carried out by different groups in different countries to examine the consistency of dosimetry codes of practice or protocols. The aim of these studies is to confirm that the goal of those codes is met, namely uniformity in establishment of dosimetry of all radiation beam types used in cancer therapy in the world

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-15

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

  7. Development of an external Faraday cup for beam current measurements

    International Nuclear Information System (INIS)

    Kim, Kye-Ryung; Jung, Myung-Hwan; Ra, Se-Jin; Lee, Seok-Ki

    2010-01-01

    In general, beam current measurements are very important for many kinds of experiments using highly energetic particle beams at accelerators, such as cyclotrons, linacs, etc. The Faraday cup is known to be one of the most popular beam current measurement tools. We developed an external Faraday cup to measure the beam current at a dedicated beam line for low-flux experiments installed at the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences (KIRAMS). It was designed for external beam current measurements and is composed of a vacuum chamber, an entrance window, a collimator, a electrostatic suppressor ring, and a cup. The window is made of 75-um-thick Kapton film, and the diameter of the collimator is 10 mm or 20 mm. The ring and the cup has 5-cm inner diameters, and the thickness of the bottom of the cup is 2 cm, which is enough to absorb the total proton energy up to 45 MeV. Using this external Faraday cup, we measured the beam current from the cyclotron, and we compared measured flux to the results from film dosimetry using GAF films.

  8. Restenosis Prevention Using Photon External Beam Radiation

    International Nuclear Information System (INIS)

    Goldstein, M.

    2002-01-01

    During transluminal coronary angioplasty, the balloon procedure is designed to crush the plaque and to support the weakened arterial wall by using the stent (an expandable metallic mesh). This procedure often tears the arterial wall as well. Some of the cells in the blood vessel respond to this injury by initiating repair which often leads to restenosis (reclosing) of the artery. In many cases restenosis occur despite the stent which become incorporated into the poliferative tissue that form around the lesion. But if the lesion is treated with radiation (8-30 Gy) the restenosis effect is inhibited. In this paper, the Adjoint Monte Carlo (AMC) method is used for external radiation treatment planning of the stent volume (the volume covered by the stent during a full cardiac cycle), while minimizing the damage to the organs at risk (OAR) and surrounding healthy tissue

  9. External beam pixe programs at the University of California, Davis

    International Nuclear Information System (INIS)

    Eldred, R.A.

    1983-01-01

    A PIXE system in which large or delicate samples are excited by a low-current external proton beam is described. This system has been used to analyze historical printed books and manuscripts, as well as a large variety of archeological artifacts. The steps used to protect the sample from unnecessary beam current are examined. A recent thorough study of the first volume of the Gutenberg 42-line Bible is described in some detail

  10. Prospective survey of erectile dysfunction after external beam radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Kikuchi, Eiji; Ando, Toshiyuki; Nagata, Hirohiko; Miyajima, Akira; Nakagawa, Ken; Oya, Mototsugu; Nakashima, Jun; Marumo, Ken

    2011-01-01

    We prospectively evaluated the effect of external beam radiotherapy on erectile function in patients with localized or locally advanced prostate cancer using the Japanese version of the International Index of Erectile Function (IIEF) survey. From 2000 to 2007, we identified 55 patients who underwent external beam radiotherapy at our institution for localized or locally advanced prostate cancer and could respond to the IIEF survey. The patients did not receive neo- and/or adjuvant hormone therapy and they were followed-up for at least 12 months after radiotherapy. Mean patient age was 69 years and the mean prostate specific antigen (PSA) level before radiotherapy was 24.9 ng/ml. First we evaluated the change of the erectile function domain score over time before and after radiotherapy. The population of severe erectile dysfunction (ED) increased while those with no or mild ED decreased after radiotherapy. The erectile function and intercourse satisfaction domain score of the IIEF declined significantly after radiotherapy, however, the orgasmic function, sexual desire, and overall satisfaction domain scores did not change after external beam radiation. Of the 34 patients who had erectile function at baseline, 10 patients could maintain erectile function 12 months after radiotherapy. Though there were no significant differences in clinical features between patients who could maintain erectile function and those who had worsening erectile function 12 months after radiotherapy, the sexual desire domain score before radiotherapy was significantly higher in patients who could maintain erectile function than their counterparts. Using the IIEF survey, external beam radiation was found to affect erectile function in patients with localized or locally advanced prostate cancer. (author)

  11. PIXE analysis using external proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Potocek, V; Potockova, J; Dzmuran, R; Sikora, J

    1985-03-01

    The possibilities were studied of the practical use of the analytical PIXE method. Calibration samples were analyzed of Cu, Cd, Hg and Pb in concentrations of 50 to 500 ..mu..g/l as well as natural samples of drinking water, pond water, human blood plasma, dry waste from ground vegetation, mushrooms, pine needles, aerosols, human hair, leaves and flowers, etc. The samples were processed using precipitation, mineralization or incineration and were trapped on a membrane filter (Synpor) or on a Tatrafan ON 15 foil. Some samples were freeze-dried and compressed into pellets. A proton beam with an intensity of 10 to 70 nA was used for analysis and the proton energy was selected 2.2 MeV. For most targets an exposure of 120 s was preset and the measurement lasted at least 60 s and 600 s at the most. It was found that Synpor filters browned and became more brittle during longer exposures. The other targets did not change during analysis.

  12. Study on external beam radiation therapy

    International Nuclear Information System (INIS)

    Kim, Mi Sook; Yoo, Seoung Yul; Yoo, Hyung Jun; Ji, Young Hoon; Lee, Dong Han; Lee, Dong Hoon; Choi, Mun Sik; Yoo, Dae Heon; Lee, Hyo Nam; Kim, Kyeoung Jung

    1999-04-01

    To develop the therapy technique which promote accuracy and convenience in external radiation therapy, to obtain the development of clinical treatment methods for the global competition. The contents of the R and D were 1. structure, process and outcome analysis in radiation therapy department. 2. Development of multimodality treatment in radiation therapy 3. Development of computation using networking techniques 4. Development of quality assurance (QA) system in radiation therapy 5. Development of radiotherapy tools 6. Development of intraoperative radiation therapy (IORT) tools. The results of the R and D were 1. completion of survey and analysis about Korea radiation therapy status 2. Performing QA analysis about ICR on cervix cancer 3. Trial of multicenter randomized study on lung cancers 4. Setting up inter-departmental LAN using MS NT server and Notes program 5. Development of ionization chamber and dose-rate meter for QA in linear accelerator 6. Development on optimized radiation distribution algorithm for multiple slice 7. Implementation on 3 dimensional volume surface algorithm and 8. Implementation on adaptor and cone for IORT

  13. Study on external beam radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Sook; Yoo, Seoung Yul; Yoo, Hyung Jun; Ji, Young Hoon; Lee, Dong Han; Lee, Dong Hoon; Choi, Mun Sik; Yoo, Dae Heon; Lee, Hyo Nam; Kim, Kyeoung Jung

    1999-04-01

    To develop the therapy technique which promote accuracy and convenience in external radiation therapy, to obtain the development of clinical treatment methods for the global competition. The contents of the R and D were 1. structure, process and outcome analysis in radiation therapy department. 2. Development of multimodality treatment in radiation therapy 3. Development of computation using networking techniques 4. Development of quality assurance (QA) system in radiation therapy 5. Development of radiotherapy tools 6. Development of intraoperative radiation therapy (IORT) tools. The results of the R and D were 1. completion of survey and analysis about Korea radiation therapy status 2. Performing QA analysis about ICR on cervix cancer 3. Trial of multicenter randomized study on lung cancers 4. Setting up inter-departmental LAN using MS NT server and Notes program 5. Development of ionization chamber and dose-rate meter for QA in linear accelerator 6. Development on optimized radiation distribution algorithm for multiple slice 7. Implementation on 3 dimensional volume surface algorithm and 8. Implementation on adaptor and cone for IORT.

  14. 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.

  15. Treatment of locally advanced breast carcinoma with high-dose external beam supervoltage radiotherapy

    International Nuclear Information System (INIS)

    Brufman, G.; Weshler, Z.; Prosnitz, L.R.; Fuks, Z.

    1981-01-01

    Between 1960 and 1978, 87 patients with locally advanced Tsub(3-4)Nsub(0-3)M 0 carcinoma of the breast were treated with 5,000 to 8,000 rad of external beam supervoltage radiotherapy. Initial clinical eradication of the tumour was observed in 76 of 87 cases (87%), but the actuarial probability of local control at 5 yr was only 53%. Furthermore, the actuarial probability of disease-free survival was 25% at 5 yr and 13% at 10 yr. Most of the patients eventually succumbed to metastatic breast carcinoma and the actuarial survival at 5 yr was 43% and at 10 yr, 16%. The addition of adjuvant low-dose chemotherapy, given to 13 patients, did not affect the rates of local control, survival or disease-free survival. The most common long-term complication was extensive and deforming radiation-induced fibrosis of the treated breast. The actuarial probability of 10-yr survival without a local recurrence and without severe fibrosis of the treated breast was only 17.5%. The role of adjuvant high-dose chemotherapy in the treatment of locally advanced breast carcinoma and the possible use of improved radiotherapy techniques to achieve a more effective long-term local control and a more desirable cosmetic end result are discussed. (author)

  16. External beam radiotherapy in the management of ovarian carcinoma

    International Nuclear Information System (INIS)

    Reinfuss, Marian; Zbigniew, Kojs; Skolyszewski, Jan

    1993-01-01

    Between 1970 and 1983, 345 patients with ovarian cancer clinical stage I, II and III were irradiated postoperatively. Five-year NED survival was achieved in 41.7% of patients. The most important prognostic factors were histological grade and clinical stage of cancer. Postoperative external beam radiotherapy appeared to be highly efficient for the patients with microscopic residual disease, giving 70% 5-year survival, and moderately efficient for patients with small, i.e. ≤3 cm in diameter residual disease, giving 40% 5-year survival. The optimal technique of irradiation appeared to be the irradiation given to the entire abdominal cavity with additional irradiation coned down to the pelvis. External beam radiotherapy was ineffective in patients with gross residual disease, i.e. >3 cm in diameter, and useless as palliative treatment given to patients with inoperable cancer of the ovary. (author). tabs., figs

  17. Generating AN Optimum Treatment Plan for External Beam Radiation Therapy.

    Science.gov (United States)

    Kabus, Irwin

    1990-01-01

    The application of linear programming to the generation of an optimum external beam radiation treatment plan is investigated. MPSX, an IBM linear programming software package was used. All data originated from the CAT scan of an actual patient who was treated for a pancreatic malignant tumor before this study began. An examination of several alternatives for representing the cross section of the patient showed that it was sufficient to use a set of strategically placed points in the vital organs and tumor and a grid of points spaced about one half inch apart for the healthy tissue. Optimum treatment plans were generated from objective functions representing various treatment philosophies. The optimum plans were based on allowing for 216 external radiation beams which accounted for wedges of any size. A beam reduction scheme then reduced the number of beams in the optimum plan to a number of beams small enough for implementation. Regardless of the objective function, the linear programming treatment plan preserved about 95% of the patient's right kidney vs. 59% for the plan the hospital actually administered to the patient. The clinician, on the case, found most of the linear programming treatment plans to be superior to the hospital plan. An investigation was made, using parametric linear programming, concerning any possible benefits derived from generating treatment plans based on objective functions made up of convex combinations of two objective functions, however, this proved to have only limited value. This study also found, through dual variable analysis, that there was no benefit gained from relaxing some of the constraints on the healthy regions of the anatomy. This conclusion was supported by the clinician. Finally several schemes were found that, under certain conditions, can further reduce the number of beams in the final linear programming treatment plan.

  18. Development and Commissioning of an External Beam Facility in the Union College Ion Beam Analysis Laboratory

    Science.gov (United States)

    Yoskowitz, Joshua; Clark, Morgan; Labrake, Scott; Vineyard, Michael

    2015-10-01

    We have developed an external beam facility for the 1.1-MV tandem Pelletron accelerator in the Union College Ion Beam Analysis Laboratory. The beam is extracted from an aluminum pipe through a 1 / 4 ' ' diameter window with a 7.5- μm thick Kapton foil. This external beam facility allows us to perform ion beam analysis on samples that cannot be put under vacuum, including wet samples and samples too large to fit into the scattering chamber. We have commissioned the new facility by performing proton induced X-ray emission (PIXE) analysis of several samples of environmental interest. These include samples of artificial turf, running tracks, and a human tooth with an amalgam filling. A 1.7-MeV external proton beam was incident on the samples positioned 2 cm from the window. The resulting X-rays were measured using a silicon drift detector and were analyzed using GUPIX software to determine the concentrations of elements in the samples. The results on the human tooth indicate that while significant concentrations of Hg, Ag, and Sn are present in the amalgam filling, only trace amounts of Hg appear to have leached into the tooth. The artificial turf and running tracks show rather large concentrations of a broad range of elements and trace amounts of Pb in the turf infill.

  19. Dose-rate effects in external beam radiotherapy redux

    International Nuclear Information System (INIS)

    Ling, C. Clifton; Gerweck, Leo E.; Zaider, Marco; Yorke, Ellen

    2010-01-01

    Recent developments in external beam radiotherapy, both in technical advances and in clinical approaches, have prompted renewed discussions on the potential influence of dose-rate on radio-response in certain treatment scenarios. We consider the multiple factors that influence the dose-rate effect, e.g. radical recombination, the kinetics of sublethal damage repair for tumors and normal tissues, the difference in α/β ratio for early and late reacting tissues, and perform a comprehensive literature review. Based on radiobiological considerations and the linear-quadratic (LQ) model we estimate the influence of overall treatment time on radio-response for specific clinical situations. As the influence of dose-rate applies to both the tumor and normal tissues, in oligo-fractionated treatment using large doses per fraction, the influence of delivery prolongation is likely important, with late reacting normal tissues being generally more sensitive to the dose-rate effect than tumors and early reacting tissues. In conventional fractionated treatment using 1.8-2 Gy per fraction and treatment times of 2-10 min, the influence of dose-rate is relatively small. Lastly, the dose-rate effect in external beam radiotherapy is governed by the overall beam-on-time, not by the average linac dose-rate, nor by the instantaneous dose-rate within individual linac pulses which could be as high as 3 x 10 6 MU/min.

  20. External Beam Radiotherapy for Carcinoma of the Extrahepatic Biliary System

    International Nuclear Information System (INIS)

    Chun, Ha Chung; Lee, Myung Za

    1996-01-01

    Purpose : To evaluate the effectiveness and tolerance of patients of external beam radiotherapy of carcinoma of the extrahepatic biliary system (EHBS) including gall bladder (GB) and extrahepatic bile ducts (EHBD) and to define the role of radiotherapy for these tumors. Methods and Materials : We retrospectively analyzed the records of 43 patients with carcinoma of the EHBS treated with external beam radiotherapy at our institution between April, 1986 and July, 1994. Twenty three patients had GB cancers and remaining 20 patients did EHBD cancers. Of those 23 GB cancers, 2 had Stage II, 12 did Stage III and 9 did Stage IV disease, respectively. Male to female ratio was 11 to 12. Fifteen patients underwent radical surgery with curative intent and 8 patients did biopsy and bypass surgery alone. Postoperatively 16 patients were irradiated with 4500 cGy or higher doses and 4 patients with 3180 to 4140 cGy. Follow up periods ranged from 8 to 34 months. Results : overall median survival time of patients with GB cancer was 11 months. Median survival time for patients with Stage III and IV disease were 14 months and 5 months, respectively. Corresponding two year survival rates were 36%(4/11) and 13%(1/8), respectively. Those who underwent surgery with curative intent showed significantly better survival at 12 months than those who underwent bypass surgery alone(67% vs 13%). None of the patients died of treatment related complications. Median survival time for entire group of 20 EHBD patients was 10 months. Median survivals of 10 Stage III and 7 Stage IV disease were 10 and 8 months, respectively. Two patients who underwent Whipple's procedure had 11 and 14 month survival and those treated with resection and drainage showed median survival of 10 month. Conclusion : Postoperative external beam radiotherapy for carcinoma of the extrahepatic billary system is well tolerated and might improve survival of patients. especially those with respectable lesions with microscopic or

  1. Flexural behaviour of RCC beams with externally bonded FRP

    Science.gov (United States)

    Vignesh, S. Arun; Sumathi, A.; Saravana Raja Mohan, K.

    2017-07-01

    The increasing use of carbon and glass fibre reinforced polymer (FRP) sheets for strengthening existing reinforced concrete beams has generated considerable interest in understanding the behavior of the FRP sheets when subjected to bending. The study on flexure includes various parameters like percentage of increase in strength of the member due to the externally bonded Fiber reinforced polymer, examining the crack patterns, reasons of debonding of the fibre from the structure, scaling, convenience of using the fibres, cost effectiveness etc. The present work aims to study experimentally about the reasons behind the failure due to flexure of an EB-FRP concrete beam by studying the various parameters. Deflection control may become as important as flexural strength for the design of FRPreinforced concrete structures. A numerical model is created using FEM software and the results are compared with that of the experiment.

  2. Elemental analysis of artefacts - establishing external beam PIXE

    International Nuclear Information System (INIS)

    Alves, A.; Johnston, P.; Short, R.; Bubb, I.

    1999-01-01

    The development of an external PIXE facility on the 1 MV Tandetron accelerator at RMIT has led to a wide range of research possibilities. A proton beam, generated inside a vacuum is brought into air via an Au coated Kapton foil exit window (thickness 8μm, diameter 0.35mm). Monitoring of the beam intensity is achieved by detecting backscattered protons from the inside Au coating on the window. Artefacts, which may be too large to be placed inside the vacuum, are positioned in the beamline opposite the exit window. An optical system consisting of a CCD camera, alignment laser and two mirrors allows viewing of a region of the target 10mm x 10mm. This technique provides quantitative analysis of elements in the pigments used in paintings and on ceramics, which is a valuable tool in art conservation and authentication. Application of the technique to a ceramic sample from the historic house 'Viewbank' is described

  3. Trace element fingerprinting of jewellery rubies by external beam PIXE

    International Nuclear Information System (INIS)

    Calligaro, T.; Poirot, J.-P.; Querre, G.

    1999-01-01

    External beam PIXE analysis allows the non-destructive in situ characterisation of gemstones mounted on jewellery pieces. This technique was used for the determination of the geographical origin of 64 rubies set on a high-valued necklace. The trace element content of these gemstones was measured and compared to that of a set of rubies of known sources. Multivariate statistical processing of the results allowed us to infer the provenance of rubies: one comes from Thailand/Cambodia deposit while the remaining are attributed to Burma. This highlights the complementary capabilities of PIXE and conventional geological observations

  4. Trace element fingerprinting of jewellery rubies by external beam PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Calligaro, T. E-mail: calli@culture.nl; Poirot, J.-P.; Querre, G

    1999-04-02

    External beam PIXE analysis allows the non-destructive in situ characterisation of gemstones mounted on jewellery pieces. This technique was used for the determination of the geographical origin of 64 rubies set on a high-valued necklace. The trace element content of these gemstones was measured and compared to that of a set of rubies of known sources. Multivariate statistical processing of the results allowed us to infer the provenance of rubies: one comes from Thailand/Cambodia deposit while the remaining are attributed to Burma. This highlights the complementary capabilities of PIXE and conventional geological observations.

  5. Bilateral Rhegmatogenous Retinal Detachment during External Beam Radiotherapy

    Directory of Open Access Journals (Sweden)

    Takako Hidaka

    2016-06-01

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

  6. External-beam PIXE analysis of small sculptures

    International Nuclear Information System (INIS)

    Gyodi, I.; Demeter, I.; Hollos-Nagy, K.; Kovacs, I.; Szokefalvi-Nagy, Z.

    1999-01-01

    Non-destructive analysis of precious art objects is an important tool to solve provenance problems or to facilitate restoration. External beam PIXE analysis is one of the most powerful and popular methods used in this respect. The paper summarises the external beam PIXE set-up at the Accelerator Laboratory in Budapest, and two selected applications are described. Different parts of a small Cambodian metal sculpture probably made in the 11th century were analysed. It was observed that the sculpture was composed of an iron core and an outer bronze shell. This sculptural technique was well known in the Middle-East but no indication has been found about its use in the Far-East, yet. Before its restoration paint traces on a wooden relief of St. Jerome made by an unknown artist in about 1600 were analysed. Different white and red paints were distinguished at selected points and the presence of titanium on a certain part of the relief was attributed to a repainting in modern times

  7. External beam radiotherapy alone in advanced esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sung Ja; Chung, Woong Ki; Nah, Byung Sik; Nam, Taek Keun [College of Medicine, Chonnam National Univ., Kwangju (Korea, Republic of)

    1999-09-01

    We performed the retrospective analysis to find the outcome of external beam radiotherapy alone in advanced esophageal cancer patients. One hundred and six patients treated with external beam radiotherapy alone between July 1990 and December 1996 were analyzed retrospectively. We limited the site of the lesions to the thoracic esophagus and cell type to the squamous cell carcinoma. Follow-up was completed in 100 patients (94%) and ranged from 1 month to 92 months (median; 6 months). The median age was 62 years old and male to female ratio was 104:2. Fifty-three percent was the middle thorax lesion and curative radiotherapy was performed in 83%. Mean tumor dose delivered with curative aim was 58.6 Gy (55-70.8 Gy) and median duration of the radiation therapy was days. The median survival of all patients was 6 months and 1-year and 2-year overall survival rate was 27% and 12%, respectively. Improvement of dysphagia was obtained in most patients except for 7 patients who underwent feeding gastrostomy. The complete response rate immediately after radiation therapy was 32% (34/106). The median survival and 2-year survival rate of the complete responder was 14 months and 30% respectively, while those of the nonresponder was 4 months and 0% respectively (p=0.000). The median survival and 2-year survival rate of the patients who could tolerate regular diet was 9 months and 16% while those of the patients who could not tolerate regular diet was 3 months and 0%, respectively (p=0.004). The survival difference between the patients with 5 cm or less tumor length and those with more than 5 cm tumor length was marginally statistically significant (p=0.06). However, the survival difference according to the periesophageal invasion or mediastinal lymphadenopathy in the chest CT imaging study was not statistically significant in this study. In a multivariate analysis, the statistically significant covariates to the survival were complete response to radiotherapy, tumor, length, and

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

    International Nuclear Information System (INIS)

    Slevin, N.J.; Irwin, C.J.R.; Banerjee, S.S.; Path, F.R.C.; Gupta, N.K.; Farrington, W.T.

    1996-01-01

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

  9. Parallel processing of dose calculation for external photon beam therapy

    International Nuclear Information System (INIS)

    Kunieda, Etsuo; Ando, Yutaka; Tsukamoto, Nobuhiro; Ito, Hisao; Kubo, Atsushi

    1994-01-01

    We implemented external photon beam dose calculation programs into a parallel processor system consisting of Transputers, 32-bit processors especially suitable for multi-processor configuration. Two network conformations, binary-tree and pipeline, were evaluated for rectangular and irregular field dose calculation algorithms. Although computation speed increased in proportion to the number of CPU, substantial overhead caused by inter-processor communication occurred when a smaller computation load was delivered to each processor. On the other hand, for irregular field calculation, which requires more computation capability for each calculation point, the communication overhead was still less even when more than 50 processors were involved. Real-time responses could be expected for more complex algorithms by increasing the number of processors. (author)

  10. Chaotic dynamics of flexible beams driven by external white noise

    Science.gov (United States)

    Awrejcewicz, J.; Krysko, A. V.; Papkova, I. V.; Zakharov, V. M.; Erofeev, N. P.; Krylova, E. Yu.; Mrozowski, J.; Krysko, V. A.

    2016-10-01

    Mathematical models of continuous structural members (beams, plates and shells) subjected to an external additive white noise are studied. The structural members are considered as systems with infinite number of degrees of freedom. We show that in mechanical structural systems external noise can not only lead to quantitative changes in the system dynamics (that is obvious), but also cause the qualitative, and sometimes surprising changes in the vibration regimes. Furthermore, we show that scenarios of the transition from regular to chaotic regimes quantified by Fast Fourier Transform (FFT) can lead to erroneous conclusions, and a support of the wavelet analysis is needed. We have detected and illustrated the modifications of classical three scenarios of transition from regular vibrations to deterministic chaos. The carried out numerical experiment shows that the white noise lowers the threshold for transition into spatio-temporal chaotic dynamics. A transition into chaos via the proposed modified scenarios developed in this work is sensitive to small noise and significantly reduces occurrence of periodic vibrations. Increase of noise intensity yields decrease of the duration of the laminar signal range, i.e., time between two successive turbulent bursts decreases. Scenario of transition into chaos of the studied mechanical structures essentially depends on the control parameters, and it can be different in different zones of the constructed charts (control parameter planes). Furthermore, we found an interesting phenomenon, when increase of the noise intensity yields surprisingly the vibrational characteristics with a lack of noisy effect (chaos is destroyed by noise and windows of periodicity appear).

  11. Improving external beam radiotherapy by combination with internal irradiation.

    Science.gov (United States)

    Dietrich, A; Koi, L; Zöphel, K; Sihver, W; Kotzerke, J; Baumann, M; Krause, M

    2015-07-01

    The efficacy of external beam radiotherapy (EBRT) is dose dependent, but the dose that can be applied to solid tumour lesions is limited by the sensitivity of the surrounding tissue. The combination of EBRT with systemically applied radioimmunotherapy (RIT) is a promising approach to increase efficacy of radiotherapy. Toxicities of both treatment modalities of this combination of internal and external radiotherapy (CIERT) are not additive, as different organs at risk are in target. However, advantages of both single treatments are combined, for example, precise high dose delivery to the bulk tumour via standard EBRT, which can be increased by addition of RIT, and potential targeting of micrometastases by RIT. Eventually, theragnostic radionuclide pairs can be used to predict uptake of the radiotherapeutic drug prior to and during therapy and find individual patients who may benefit from this treatment. This review aims to highlight the outcome of pre-clinical studies on CIERT and resultant questions for translation into the clinic. Few clinical data are available until now and reasons as well as challenges for clinical implementation are discussed.

  12. Biochemical failure after radical external beam radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Nomoto, Satoshi; Imada, Hajime; Kato, Fumio; Yahara, Katsuya; Morioka, Tomoaki; Ohguri, Takayuki; Nakano, Keita; Korogi, Yukunori

    2005-01-01

    The purpose of this study was to evaluate biochemical failures after radical external beam radiotherapy for prostate cancer. A total of 143 patients with prostate cancer (5 cases in stage A2, 95 in stage B and 43 in stage C; 18 in low risk group, 37 in intermediate risk group, 67 in high risk group and 21 in unknown group) were included in this study. Patients of stage A2 and B underwent external irradiation of 46 Gy to the prostate gland and seminal vesicle and additional 20 Gy to the prostate gland, while patients of stage C underwent external irradiation of 66 Gy to the prostate gland and seminal vesicle including 46 Gy to the pelvis. Neoadjuvant hormonal therapy was done in 66 cases, and long-term hormonal therapy in 75 cases; two cases were treated with radiation therapy alone. The 3-year relapse free survival rates by stage A2, B and C were 100%, 96.7% and 88.1%, respectively. The 3-year relapse free survival rates by low, intermediate and high risk groups were 100%, 92.3% and 89.7%, respectively. Biochemical failure was noted in nine cases during the average observation term of 32.2 months; in this group the median of prostate specific antigen (PSA) value was 2.6 ng/ml, the doubling time was 8.6 months, and the term of biochemical failure was 33.2 months. Six of eight cases with biochemical failure were the neoadjuvant hormonal therapy group, but biochemical no evidence of disease (bNED) curve showed no significant difference between neoadjuvant and long-term hormonal groups. It is supposed that unnecessary hormonal therapies were performed based on the nonspecific diagnosis of biochemical failure after radical radiotherapy in our group of patients. A precise criterion of biochemical failure after radical radiotherapy for prostate cancer is necessary. (author)

  13. Prestress Force Identification for Externally Prestressed Concrete Beam Based on Frequency Equation and Measured Frequencies

    Directory of Open Access Journals (Sweden)

    Luning Shi

    2014-01-01

    Full Text Available A prestress force identification method for externally prestressed concrete uniform beam based on the frequency equation and the measured frequencies is developed. For the purpose of the prestress force identification accuracy, we first look for the appropriate method to solve the free vibration equation of externally prestressed concrete beam and then combine the measured frequencies with frequency equation to identify the prestress force. To obtain the exact solution of the free vibration equation of multispan externally prestressed concrete beam, an analytical model of externally prestressed concrete beam is set up based on the Bernoulli-Euler beam theory and the function relation between prestress variation and vibration displacement is built. The multispan externally prestressed concrete beam is taken as the multiple single-span beams which must meet the bending moment and rotation angle boundary conditions, the free vibration equation is solved using sublevel simultaneous method and the semi-analytical solution of the free vibration equation which considered the influence of prestress on section rigidity and beam length is obtained. Taking simply supported concrete beam and two-span concrete beam with external tendons as examples, frequency function curves are obtained with the measured frequencies into it and the prestress force can be identified using the abscissa of the crosspoint of frequency functions. Identification value of the prestress force is in good agreement with the test results. The method can accurately identify prestress force of externally prestressed concrete beam and trace the trend of effective prestress force.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-01

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

  15. External Validation and Optimization of International Consensus Clinical Target Volumes for Adjuvant Radiation Therapy in Bladder Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Abhinav V. [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Christodouleas, John P. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Wu, Tianming [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Smith, Norman D.; Steinberg, Gary D. [Section of Urology, Department of Surgery, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Liauw, Stanley L., E-mail: sliauw@radonc.uchicago.edu [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States)

    2017-03-15

    Purpose: International consensus (IC) clinical target volumes (CTVs) have been proposed to standardize radiation field design in the treatment of patients at high risk of locoregional failure (LRF) after radical cystectomy. The purpose of this study was to externally validate the IC CTVs in a cohort of postsurgical patients followed up for LRF and identify revisions that might improve the IC CTVs' performance. Methods and Materials: Among 334 patients with pT3 to pT4 bladder cancer treated with radical cystectomy, LRF developed in 58 (17%), of whom 52 had computed tomography scans available for review. Images with LRF were exported into a treatment planning system, and IC CTVs were contoured and evaluated for adequacy of coverage of each LRF with respect to both the patient and each of 6 pelvic subsites: common iliac (CI) region, obturator region (OR), external and internal iliac region, presacral region, cystectomy bed, or other pelvic site. Revisions to the IC contours were proposed based on the findings. Results: Of the 52 patients with documented LRF, 13 (25%) had LRFs that were outside of the IC CTV involving 17 pelvic subsites: 5 near the CI CTV, 5 near the OR CTV, 1 near the external and internal iliac region, and 6 near the cystectomy bed. The 5 CI failures were located superior to the CTV, and the 5 OR failures were located medial to the CTV. Increasing the superior boundary of the CI to a vessel-based definition of the aortic bifurcation, as well as increasing the medial extension of the OR by an additional 9 mm, decreased the number of patients with LRF outside of the IC CTV to 7 (13%). Conclusions: Modified IC CTVs inclusive of a slight adjustment superiorly for the CI region and medially for the OR may reduce the risk of pelvic failure in patients treated with adjuvant radiation therapy.

  16. Ocular complications after external-beam irradiation - a literature overview

    International Nuclear Information System (INIS)

    Ziolkowska, E.; Zarzycka, M.; Wisniewski, T.; Meller, A.

    2009-01-01

    Radiotherapy is one of the treatment methods applied to patients suffering from head and neck cancer. The efficiency of this method is comparable to surgery, yet it allows one to save the organ and avoid its permanent deformation. In the case of radiation not only the tumour is influenced but the surrounding, normal structures as well. Radiation causes deformation of normal structures as early or side effects. The aim of this study is to present plausible ocular complications after external beam irradiation of head and neck cancer, such as radiation- induced cataract, radiation retinopathy, dry-eye syndrome or radiation neuropathy. By the use of basic principles of radiotherapy planning we can avoid or minimize possible ocular complications occurring after irradiation. The treatment of ocular complications is difficult and very often does not give the expected outcome. Therefore, in such cases in order to restore vision surgery is required. This study shows that radiotherapy can be helpful but can increase the risk of occurrence of some ocular complications. (authors)

  17. Interstitial gold and external beam irradiation for prostate cancer

    International Nuclear Information System (INIS)

    Boileau, M.A.; Dowling, R.A.; Gonzales, M.; Handel, P.H.; Benson, G.S.; Corriere, J.N. Jr.

    1988-01-01

    We treated 65 patients with prostatic cancer confined clinically to the prostate or periprostatic area during an 8-year period. Seven patients had stage A2, 38 stage B and 20 stage C disease. All 65 patients underwent staging pelvic lymphadenectomy and implantation of gold grains into the prostate (mean dose 3,167 rad). A total of 64 patients then completed a course of external beam irradiation to a mean total tumor dose of 6,965 rad. Complications of therapy were mild and limited (less than 3 months in duration) in most patients, and they included radiation cystitis (32 per cent), diarrhea (31 per cent), extremity lymphedema (7.7 per cent) and wound infection (3 per cent). Two patients suffered urinary incontinence after therapy and 2 (3 per cent) had diarrhea more than 3 months in duration. The actuarial 5-year survival rate for all patients was 87 per cent and the 5-year survival free of disease was 72 per cent

  18. Cracking of Beams Strengthened with Externally Bonded SRP Tapes

    Science.gov (United States)

    Krzywoń, Rafał

    2017-10-01

    Paper discusses strengthening efficiency of relatively new kind of SRP composite based on high strength steel wires. They are made of ultra-high strength steel primarily used in cords of car tires. Through advanced treatment, the mechanical properties of SRP steel are similar to other high carbon cold drawn steels used in construction industry. Strength significantly exceed 2000 MPa, there is no perfect plasticity at yield stress level. Almost linear stress-strain relationship makes SRP steel mechanical properties similar to carbon fibers. Also flexibility and weight ratio of the composite overlay is slightly worse than CFRP strip. Despite these advantages SRP is not as popular as other composites reinforced with fibers of high strength. This is due to the small number of studies of SRP behavior and applicability. Paper shows selected results of the laboratory test of beams strengthened with use of SRP and CFRP externally bonded overlays. Attention has been focused primarily on the phenomenon of cracking. Comparison include the cracking moment, crack width and spacing, coverage of crack zone. Despite the somewhat lower rigidity of SRP tapes, they have a much better adhesion to concrete, so that the crack width is comparable in almost the whole load range. The paper also includes an assessment of the common methods of checking the condition of cracking in relation to the tested SRP strengthening. The paper presents actual calculation procedures to determine the crack spacing and crack width. The discussed formulas are verified with results of provided laboratory tests.

  19. Intraoperative plus external beam irradiation in nonresectable lung cancer

    International Nuclear Information System (INIS)

    Arian-Schad, K.S.; Juettner, F.M.; Ratzenhofer, B.; Leitner, H.; Porsch, G.; Pinter, H.; Ebner, F.; Hackl, A.G.; Friehs, G.B.

    1990-01-01

    Since 1987, 24 patients with inoperable non-small-cell lung cancer (NSCLC), stage T 1-3 N 0-2 M 0 , have undergone lymph node dissection and intraoperative radiation therapy (IORT) to the primary with 10-20 Gy. Patient selection criteria were nonresectability based on severe cardiorespiratory impairment, no radiological evidence of distant metastases and a Karnofsky performance status of >80. In 18 patients the IORT procedure was followed by an external beam radiation series (EBR) including the tumor with 46 Gy and the regional lymph nodes with 45/56 Gy. The tumor response was assessed by CAT-scan volumetry before the institution of IORT, 4 weeks later, before the onset of EBR, 8 weeks after the combined treatment course and on a 3 months basis thereafter. Prospectively, MRI of the thorax with/without Gadolinium-DTPA was performed to examine contrast enhancement and signal behavior of the tumor, in an attempt to differentiate residual disease compared to therapy-related collateral damage. So far, 18 patients have completed the combined treatment course with a median follow-up of 11 months (range 4.5 to 25 months). The overall local response rate (CR and PR) was 88.2 per cent. In detail, 11 complete responses, 6 partial responses and one minimal response were observed. The overall and recurrent-free survival at 25 months was 49.6 per cent and 83.3 per cent, respectively. (author). 31 refs.; 2 figs.; 3 tabs

  20. Severe dry-eye syndrome following external beam irradiation

    International Nuclear Information System (INIS)

    Parsons, J.T.; Bova, F.J.; Million, R.R.

    1994-01-01

    There are limited data in the literature on the probability of dry-eye complications according to radiotherapy dose. This study investigates the risk of radiation-induced severe dry-eye syndrome in patients in whom an entire orbit was exposed to fractionated external beam irradiation. Between October 1964 and May 1989, 33 patients with extracranial head and neck tumors received irradiation of an entire orbit. Most patients were treated with 60 Co. The dose to the lacrimal apparatus was calculated at a depth of 1 cm from the anterior skin surface, the approximate depth of the major lacrimal gland. The end point of the study was severe dry-eye syndrome sufficient to produce visual loss secondary to corneal opacification, ulceration, or vascularization. Twenty patients developed severe dry-eye syndrome. All 17 patients who received dose ≥57Gy developed severe dry-eye syndrome. Three (19%) of 16 patients who received doses ≥45 Gy developed severe dry-eye syndrome; injuries in the latter group were much more slower to develop (4 to 11 years) than in the higher dose group, in whom corneal vascularization and opacification were usually pronounced within 9-10 months. There were no data for the range of doses between 45.01 and 56.99 Gy. The data did not suggest an increased risk of severe dry-eye syndrome with increasing age. Data from the current series and the literature are combined to construct a sigmoid dose response curve. The incidence of injury increases from 0% reported after doses ≥30 Gy to 100% after doses ≥57 Gy. 13 refs., 3 figs., 5 tabs

  1. Intraoperative and external beam radiotherapy for pancreatic carcinoma; Intraoperative und perkutane Radiotherapie des Pankreaskarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Eble, M.J. [Abt. Klinische Radiologie, Radiologische Universitaetsklinik Heidelberg (Germany); Maurer, U. [Klinikum der Stadt Mannheim (Germany). Inst. fuer Radiologie

    1996-05-01

    Therapeutic strategies in the treatment of pancreatic carcinoma are based on the high number of non-resectable cancers, the high relative radioresistance and the high distant metastases rate. Even in curatively resected carcinomas, a locally effective treatment modality is needed because of the risk of microscopical residual disease in the peripancreatic tissue. The efficacy of radiotherapy is dose dependent. Based on an analysis of published data a dose of more than 50 Gy is recommended, resulting in a high morbidity rate with external beam radiotherapy alone. The use of intraoperative radiotherapy allows locally restricted dose escalation without increased perioperative morbidity. In adjuvant and in primary treatment, local tumor control was improved (70-90%). With palliative intent, pain relief was obtained rapidly in over 60% of patients and led to improved patient performance. As a result of the high distant metastases rate, even in curatively resected carcinomas, the overall prognosis could not be significantly improved. Further dose escalation is limited by the increasing incidence of upper gastrointestinal bleeding (20-30%). (orig.) [Deutsch] Therapiestrategien beim Pankreaskarzinom werden bestimmt durch den hohen Anteil primaer nicht resektabler Karzinome, der hohen relativen Strahlenresistenz und der hohen Fernmetastasierungsrate. Selbst kurativ resezierte Karzinome erfordern durch ihre hohe lokale Tumorzellpersistenz eine lokal effektive adjuvante Behandlungsmassnahme. Die Effektivitaet einer Radiotherapie ist dosisabhaengig. Aus der Analyse publizierter Daten wird eine Dosis von >50 Gy, welche bei der alleinigen perkutanen Bestrahlung mit einer hohen Morbiditaet verbunden ist, empfohlen. Mit der intraoperativen Radiotherapie ist eine lokal begrenzte Dosiseskalation ohne erhoehte perioperative Morbiditaet moeglich. Sowohl in der adjuvanten als auch in der primaeren Behandlung kann die lokale Tumorkontrolle deutlich verbessert werden (70-90%). Unter

  2. Two-stream instability for a light ion beam-plasma system with external magnetic field

    International Nuclear Information System (INIS)

    Okada, T.; Tazawa, H.

    1992-12-01

    For inertial confinement fusion, a focused light ion beam (LIB) is required to propagate stably through a chamber to a target. We have pointed out that the applied external magnetic field is important for LIB propagation. To investigate the influence of the external magnetic field on the LIB propagation, we analysed the electrostatic dispersion relation of magnetized light ion beam-plasma system. The particle in-cell (PIC) simulation results are presented for a light ion beam-plasma system with external magnetic field. (author)

  3. Realistic respiratory motion margins for external beam partial breast irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Leigh; Quirk, Sarah [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Smith, Wendy L., E-mail: wendy.smith@albertahealthservices.ca [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Department of Oncology, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)

    2015-09-15

    Purpose: Respiratory margins for partial breast irradiation (PBI) have been largely based on geometric observations, which may overestimate the margin required for dosimetric coverage. In this study, dosimetric population-based respiratory margins and margin formulas for external beam partial breast irradiation are determined. Methods: Volunteer respiratory data and anterior–posterior (AP) dose profiles from clinical treatment plans of 28 3D conformal radiotherapy (3DCRT) PBI patient plans were used to determine population-based respiratory margins. The peak-to-peak amplitudes (A) of realistic respiratory motion data from healthy volunteers were scaled from A = 1 to 10 mm to create respiratory motion probability density functions. Dose profiles were convolved with the respiratory probability density functions to produce blurred dose profiles accounting for respiratory motion. The required margins were found by measuring the distance between the simulated treatment and original dose profiles at the 95% isodose level. Results: The symmetric dosimetric respiratory margins to cover 90%, 95%, and 100% of the simulated treatment population were 1.5, 2, and 4 mm, respectively. With patient set up at end exhale, the required margins were larger in the anterior direction than the posterior. For respiratory amplitudes less than 5 mm, the population-based margins can be expressed as a fraction of the extent of respiratory motion. The derived formulas in the anterior/posterior directions for 90%, 95%, and 100% simulated population coverage were 0.45A/0.25A, 0.50A/0.30A, and 0.70A/0.40A. The differences in formulas for different population coverage criteria demonstrate that respiratory trace shape and baseline drift characteristics affect individual respiratory margins even for the same average peak-to-peak amplitude. Conclusions: A methodology for determining population-based respiratory margins using real respiratory motion patterns and dose profiles in the AP direction was

  4. Realistic respiratory motion margins for external beam partial breast irradiation

    International Nuclear Information System (INIS)

    Conroy, Leigh; Quirk, Sarah; Smith, Wendy L.

    2015-01-01

    Purpose: Respiratory margins for partial breast irradiation (PBI) have been largely based on geometric observations, which may overestimate the margin required for dosimetric coverage. In this study, dosimetric population-based respiratory margins and margin formulas for external beam partial breast irradiation are determined. Methods: Volunteer respiratory data and anterior–posterior (AP) dose profiles from clinical treatment plans of 28 3D conformal radiotherapy (3DCRT) PBI patient plans were used to determine population-based respiratory margins. The peak-to-peak amplitudes (A) of realistic respiratory motion data from healthy volunteers were scaled from A = 1 to 10 mm to create respiratory motion probability density functions. Dose profiles were convolved with the respiratory probability density functions to produce blurred dose profiles accounting for respiratory motion. The required margins were found by measuring the distance between the simulated treatment and original dose profiles at the 95% isodose level. Results: The symmetric dosimetric respiratory margins to cover 90%, 95%, and 100% of the simulated treatment population were 1.5, 2, and 4 mm, respectively. With patient set up at end exhale, the required margins were larger in the anterior direction than the posterior. For respiratory amplitudes less than 5 mm, the population-based margins can be expressed as a fraction of the extent of respiratory motion. The derived formulas in the anterior/posterior directions for 90%, 95%, and 100% simulated population coverage were 0.45A/0.25A, 0.50A/0.30A, and 0.70A/0.40A. The differences in formulas for different population coverage criteria demonstrate that respiratory trace shape and baseline drift characteristics affect individual respiratory margins even for the same average peak-to-peak amplitude. Conclusions: A methodology for determining population-based respiratory margins using real respiratory motion patterns and dose profiles in the AP direction was

  5. Suppression of beam-excited electron waves by an externally applied RF signal

    International Nuclear Information System (INIS)

    Fukumasa, Osamu; Itatani, Ryohei

    1980-11-01

    Suppression of the beam-excited electron wave in a bounded system is investigated in connection with the beam distribution function. Wave suppression has two different processes depending on whether injected beams are reflected at the other end or not. In the absence of reflected beam electrons, deformation of the beam distribution function is observed in relation to the suppression of the electron wave. However, when beam electrons are reflected, the external wave suppresses the electron wave but distribution function shows no appreciable change. These experimental results show that nonlinear behaviors of beam electrons, namely behaviors of reflected beams, are quite important for wave suppression. By using the method of partial simulation, interaction between two waves in the bounded system including nonlinear motions of beam electrons is studied numerically. Qualitative agreement between experimental and numerical results is obtained. (author)

  6. A TCP model for external beam treatment of intermediate-risk prostate cancer.

    LENUS (Irish Health Repository)

    Walsh, Seán

    2013-03-01

    Biological models offer the ability to predict clinical outcomes. The authors describe a model to predict the clinical response of intermediate-risk prostate cancer to external beam radiotherapy for a variety of fractionation regimes.

  7. External influences and priority-setting for anti-cancer agents: a case study of media coverage in adjuvant trastuzumab for breast cancer

    Directory of Open Access Journals (Sweden)

    Fralick John

    2007-06-01

    Full Text Available Abstract Background Setting priorities for the funding of new anti-cancer agents is becoming increasingly complex. The funding of adjuvant trastuzumab for breast cancer has brought this dilemma to the fore. In this paper we review external factors that may influence decision-making bodies and present a case study of media response in Ontario, Canada to adjuvant trastuzumab for breast cancer. Methods A comprehensive search of the databases of Canadian national and local newspapers and television was performed. Articles pertaining to trastuzumab in adjuvant breast cancer as well as 17 other anti-cancer drugs and indications were retrieved. The search period was from the date when individual trial results were announced to the date funding was made available in Ontario. Results During the 2.6 months between the release of the trastuzumab results to funding approval in Ontario, we identified 51 episodes of media coverage. For the 17 other drugs/indications (7 breast and 10 non-breast, the median time to funding approval was 31 months (range 14–46. Other recent major advances in oncology such as adjuvant vinorelbine/cisplatin for resected NSCLC and docetaxel for advanced prostate cancer received considerably less media attention (17 media reports for each than trastuzumab. The median number of media reports for breast cancer drugs was 4.5 compared to 2.5 for non-breast cancer drugs (p = 0.56. Conclusion Priority-setting for novel anti-cancer agents is a complex process that tries to ensure fair use of constrained resources to fund therapies with the best evidence of clinical benefit. However, this process is subject to external factors including the influence of media, patient advocates, politicians, and industry. The data in this case study serve to illustrate the significant involvement one (or all of these external factors may play in the debate over priority-setting.

  8. Self-Nulling Beam Combiner Using No External Phase Inverter

    Science.gov (United States)

    Bloemhof, Eric E.

    2010-01-01

    A self-nulling beam combiner is proposed that completely eliminates the phase inversion subsystem from the nulling interferometer, and instead uses the intrinsic phase shifts in the beam splitters. Simplifying the flight instrument in this way will be a valuable enhancement of mission reliability. The tighter tolerances on R = T (R being reflection and T being transmission coefficients) required by the self-nulling configuration actually impose no new constraints on the architecture, as two adaptive nullers must be situated between beam splitters to correct small errors in the coatings. The new feature is exploiting the natural phase shifts in beam combiners to achieve the 180 phase inversion necessary for nulling. The advantage over prior art is that an entire subsystem, the field-flipping optics, can be eliminated. For ultimate simplicity in the flight instrument, one might fabricate coatings to very high tolerances and dispense with the adaptive nullers altogether, with all their moving parts, along with the field flipper subsystem. A single adaptive nuller upstream of the beam combiner may be required to correct beam train errors (systematic noise), but in some circumstances phase chopping reduces these errors substantially, and there may be ways to further reduce the chop residuals. Though such coatings are beyond the current state of the art, the mechanical simplicity and robustness of a flight system without field flipper or adaptive nullers would perhaps justify considerable effort on coating fabrication.

  9. Successful delivery of adjuvant external beam radiotherapy for ependymoma in a patient with Ondine's curse

    International Nuclear Information System (INIS)

    Choi, Mehee; Thoma, Miranda; Tolekidis, George; Byrne, Richard W.; Diaz, Aidnag Z.

    2015-01-01

    Ondine's curse is a rare, potentially life-threatening disorder characterized by loss of automatic breathing during sleep and preserved voluntary breathing. It is seldom encountered in the radiotherapy clinic but can pose significant technical challenges and safety concerns in the delivery of a prescribed radiation course. We report a unique case of successful delivery of radiotherapy for ependymoma in a patient with Ondine's curse. A 53-year-old gentleman presented with vertigo when lying down. Brain magnetic resonance imaging revealed an enhancing mass in the floor of the fourth ventricle. He underwent maximal safe resection. Pathology revealed ependymoma. The patient was referred for radiotherapy. Computed tomography simulation was performed in supine position with 3-point thermoplastic mask immobilization. Sequential TomoTherapy plans were developed. At first scheduled treatment, shortly after mask placement, his arms went limp and he was unresponsive. Vitals showed oxygen saturation 83%, pulse 127, and blood pressure 172/97 mm Hg. He was diagnosed with Ondine's curse thought secondary to previous brainstem damage; the combination of lying flat and pressure from the mask was causing him to go into respiratory arrest. As supine positioning did not seem clinically advisable, he was simulated in prone position. A RapidArc plan and a back-up conformal plan were developed. Prescriptions were modified to meet conservative organs-at-risk constraints. Several strategies were used to minimize uncertainties in set-up reproducibility associated with prone positioning. He tolerated prone RapidArc treatments well. The report highlights the importance of applying practical patient safety and treatment planning/delivery strategies in the management of this challenging case.

  10. tion using external beam radiation in gynaecological cancers

    African Journals Online (AJOL)

    Enrique

    The purpose of the modified technique is: (i) to accurately assess the lower extent of the disease and define the lower border of the external radiation field in both the anteropos- terior/ posteroanterior (AP/PA) and lateral fields; and (ii) to decrease the field size and reduce treatment-related side-effects. Methods and materials.

  11. 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

  12. Wavelength beam combining of a 980-nm tapered diode laser bar in an external cavity

    DEFF Research Database (Denmark)

    Vijayakumar, Deepak; Jensen, Ole Bjarlin; Thestrup Nielsen, Birgitte

    2010-01-01

    solution for preserving the beam quality of the bar in the range of that of a single emitter and at the same time, enabling the power scaling. We report spectral beam combining applied to a 12 emitter tapered laser bar at 980 nm. The external cavity has been designed for a wavelength separation of 4.0 nm......High power diode lasers are used in a large number of applications. A limiting factor for more widespread use of broad area lasers is the poor beam quality. Gain guided tapered diode lasers are ideal candidates for industrial applications that demands watt level output power with good beam quality...

  13. External beam radiotherapy boosted with high dose rate brachytherapy in completely resected uterine sarcomas. Is this a treatment option?

    Energy Technology Data Exchange (ETDEWEB)

    Pellizzon, Antonio Cassio Assis; Novaes, Paulo Eduardo Ribeiro dos Santos; Maia, Maria Aparecida Conte; Ferrigno, Robson; Fogarolli, Ricardo; Salvajoli, Joao Vitor [Hospital de Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Oncologia de Radiacao]. E-mail: pellizzon@aol.com

    2005-04-15

    Uterine sarcoma (US) is a relative rare tumor, which accounts for only about 3-5% of all uterine cancers. Aggressive cytoreductive surgery at the time of the initial diagnosis with maximum tumor debulking may lead to a prolonged survival or cure. Objective: to identify and review the role of adjuvant external beam radiation therapy (EBRT) associated with high dose rate brachytherapy (HDRB) in the management of patients presenting US with complete resection. Material and methods: this study is a retrospective analysis of 23 patients with US treated from 10/92 to 03/03, with surgery, external beam radiation therapy (EBRT) and high dose rate brachytherapy (HDRB). The inclusion criteria for study participation included: histologically proven and graded US, completely resection of tumor, Karnofsky status 60-100, absence of significant infection, and recovery from recent surgery. Results: The median age of patients was 62 years (range 39-84); ten-year actuarial disease-free and overall survivals were 42.2% and 63.4%, respectively. On univariate analysis, predictive factors for disease-free survival (DFS) were age at initial presentation (p=0.0268), parity (p=0.0441), tumor grade (p= 0.0095), cervical or vaginal invasion (p=0.0014) and node dissection at time of surgery (p= 0.0471). On multivariate analysis, the only predictive factor was cervical or vaginal invasion (p= 0.048), hazard ratio of 4.7. Conclusion: it is quite likely that neither radiotherapy nor chemotherapy alone will appreciably improve survival in US. If radiation therapy provides better locoregional tumor control, hematogenous metastases will assume an even greater proportion of treatment failures. Unfortunately, our small and heterogeneous group analyzed precludes any definitive conclusions about the impact of HDRB associated to EBRT radiation therapy on recurrence or survival. (author)

  14. External beam radiotherapy boosted with high dose rate brachytherapy in completely resected uterine sarcomas. Is this a treatment option?

    International Nuclear Information System (INIS)

    Pellizzon, Antonio Cassio Assis; Novaes, Paulo Eduardo Ribeiro dos Santos; Maia, Maria Aparecida Conte; Ferrigno, Robson; Fogarolli, Ricardo; Salvajoli, Joao Vitor

    2005-01-01

    Uterine sarcoma (US) is a relative rare tumor, which accounts for only about 3-5% of all uterine cancers. Aggressive cytoreductive surgery at the time of the initial diagnosis with maximum tumor debulking may lead to a prolonged survival or cure. Objective: to identify and review the role of adjuvant external beam radiation therapy (EBRT) associated with high dose rate brachytherapy (HDRB) in the management of patients presenting US with complete resection. Material and methods: this study is a retrospective analysis of 23 patients with US treated from 10/92 to 03/03, with surgery, external beam radiation therapy (EBRT) and high dose rate brachytherapy (HDRB). The inclusion criteria for study participation included: histologically proven and graded US, completely resection of tumor, Karnofsky status 60-100, absence of significant infection, and recovery from recent surgery. Results: The median age of patients was 62 years (range 39-84); ten-year actuarial disease-free and overall survivals were 42.2% and 63.4%, respectively. On univariate analysis, predictive factors for disease-free survival (DFS) were age at initial presentation (p=0.0268), parity (p=0.0441), tumor grade (p= 0.0095), cervical or vaginal invasion (p=0.0014) and node dissection at time of surgery (p= 0.0471). On multivariate analysis, the only predictive factor was cervical or vaginal invasion (p= 0.048), hazard ratio of 4.7. Conclusion: it is quite likely that neither radiotherapy nor chemotherapy alone will appreciably improve survival in US. If radiation therapy provides better locoregional tumor control, hematogenous metastases will assume an even greater proportion of treatment failures. Unfortunately, our small and heterogeneous group analyzed precludes any definitive conclusions about the impact of HDRB associated to EBRT radiation therapy on recurrence or survival. (author)

  15. A quality audit program for external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-31

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

  16. A quality audit program for external beam radiotherapy

    International Nuclear Information System (INIS)

    Hanson, W.F.; Stovall, M.

    1993-01-01

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

  17. Performance of Retrofitted Self-Compacting Concrete-Filled Steel Tube Beams Using External Steel Plates

    Directory of Open Access Journals (Sweden)

    Ahmed A. M. AL-Shaar

    2018-01-01

    Full Text Available Self-compacting concrete-filled steel tube (SCCFST beams, similar to other structural members, necessitate retrofitting for many causes. However, research on SCCFST beams externally retrofitted by bolted steel plates has seldom been explored in the literature. This paper aims at experimentally investigating the retrofitting performance of square self-compacting concrete-filled steel tube (SCCFST beams using bolted steel plates with three different retrofitting schemes including varied configurations and two different steel plate lengths under flexure. A total of 18 specimens which consist of 12 retrofitted SCCFST beams, three unretrofitted (control SCCFST beams, and three hollow steel tubes were used. The flexural behaviour of the retrofitted SCCFST beams was examined regarding flexural strength, failure modes, and moment versus deflection curves, energy absorption, and ductility. Experimental results revealed that the implemented retrofitting schemes efficiently improve the moment carrying capacity and stiffness of the retrofitted SCCFST beams compared to the control beams. The increment in flexural strength ranged from 1% to 46%. Furthermore, the adopted retrofitting schemes were able to restore the energy absorption and ductility of the damaged beams in the range of 35% to 75% of the original beam ductility. Furthermore, a theoretical model was suggested to predict the moment capacity of the retrofitted SCCFST beams. The theoretical model results were in good agreement with the test results.

  18. External beam monitoring of the Cyclone 30 cyclotron of IPEN-CNEN-SP

    International Nuclear Information System (INIS)

    Matsuda, Hylton

    2002-01-01

    Due to the increasing demand for cyclotron radioisotopes and the high cost of equipment and materials involved in the process, it becomes evident the importance of external beam monitoring of the cyclotron. In this way, the beam of the Cyclone 30 cyclotron of IPEN-CNEN/S P was characterized throughout the evaluation of its current intensity, profile (position, focus and geometry), alignment and homogeneity, by measuring currents, temperatures and pressures of irradiation systems. For this purpose, techniques and conventional devices, thermocouples and pressure sensors associated to electronic of instrumentation, and technology and flexibility of micro controllers allowed observing the beam behavior during irradiations in real time. The ion beam energy was also evaluated using activation analysis technique of monitor reactions in nat Cu. The beam monitoring systems have been contributing to prevent material damages and they have already been used in routine irradiations, bringing important advantages in the process of beam optimization of the Cyclone 30. (author)

  19. Effect of beam arrangement on oral cavity dose in external beam radiotherapy of nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Wu, Vincent W.C.; Yang Zhining; Zhang Wuzhe; Wu Lili; Lin Zhixiong

    2012-01-01

    This study compared the oral cavity dose between the routine 7-beam intensity-modulated radiotherapy (IMRT) beam arrangement and 2 other 7-beam IMRT with the conventional radiotherapy beam arrangements in the treatment of nasopharyngeal carcinoma (NPC). Ten NPC patients treated by the 7-beam routine IMRT technique (IMRT-7R) between April 2009 and June 2009 were recruited. Using the same computed tomography data, target information, and dose constraints for all the contoured structures, 2 IMRT plans with alternative beam arrangements (IMRT-7M and IMRT-7P) by avoiding the anterior facial beam and 1 conventional radiotherapy plan (CONRT) were computed using the Pinnacle treatment planning system. Dose-volume histograms were generated for the planning target volumes (PTVs) and oral cavity from which the dose parameters and the conformity index of the PTV were recorded for dosimetric comparisons among the plans with different beam arrangements. The dose distributions to the PTVs were similar among the 3 IMRT beam arrangements, whereas the differences were significant between IMRT-7R and CONRT plans. For the oral cavity dose, the 3 IMRT beam arrangements did not show significant difference. Compared with IMRT-7R, CONRT plan showed a significantly lower mean dose, V30 and V-40, whereas the V-60 was significantly higher. The 2 suggested alternative beam arrangements did not significantly reduce the oral cavity dose. The impact of varying the beam angles in IMRT of NPC did not give noticeable effect on the target and oral cavity. Compared with IMRT, the 2-D conventional radiotherapy irradiated a greater high-dose volume in the oral cavity.

  20. Adjuvant radiotherapy for stage I endometrial cancer.

    Science.gov (United States)

    Kong, A; Johnson, N; Cornes, P; Simera, I; Collingwood, M; Williams, C; Kitchener, H

    2007-04-18

    The role of adjuvant radiotherapy (both pelvic external beam radiotherapy and vaginal intracavity brachytherapy) in stage I endometrial cancer following total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH and BSO) remains unclear. To assess the efficacy of adjuvant radiotherapy following surgery for stage I endometrial cancer. The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CancerLit, Physician Data Query (PDQ) of National Cancer Institute. Handsearching was also carried out where appropriate. Randomised controlled trials (RCTs) which compared adjuvant radiotherapy versus no radiotherapy following surgery for patients with stage I endometrial cancer were included. Quality of the studies was assessed and data collected using a predefined data collection form. The primary endpoint was overall survival. Secondary endpoints were locoregional recurrence, distant recurrence and endometrial cancer death. Data on quality of life (QOL) and morbidity were also collected. A meta-analysis on included trials was performed using the Cochrane Collaboration Review Manager Software 4.2. The meta-analysis was performed on four trials (1770 patients). The addition of pelvic external beam radiotherapy to surgery reduced locoregional recurrence, a relative risk (RR) of 0.28 (95% confidence interval (CI) 0.17 to 0.44, p ASTEC; Lukka) are awaited. External beam radiotherapy carries a risk of toxicity and should be avoided in stage 1 endometrial cancer patients with no high risk factors.

  1. Characterization of mercury gilding art objects by external proton beam

    International Nuclear Information System (INIS)

    Corregidor, V.; Alves, L.C.; Barradas, N.P.; Reis, M.A.; Marques, M.T.; Ribeiro, J.A.

    2011-01-01

    The fire gilding is one of the methods used by the ancient goldsmiths to obtain a rich, metallic glow and durable golden appearance in ornamental objects. This layer is characterized, among others, by its thickness (several microns) a diffusion profile and a Hg content (between 0 and 21 wt.%) depending on the temperatures achieved during the process. Gilded sacral art objects dated from the XVI to the XVIII centuries, belonging to the Casa-Museu Dr. Anastácio Gonçalves Collection (Lisbon) were analyzed using the external ion microprobe at Nuclear and Technological Institute, Lisbon. The average concentrations of the homogeneous areas were calculated with GUPIX, DATTPIXE and NDF codes showing very similar results. The RBS and PIXE spectra from the same point were collected simultaneously and analyzed together with NDF-LibCPIXE in order to find self-consistent solutions. Profile concentration on particular Au-reach points was extracted. Different Hg and Au/Ag ratio have been found in the pieces dating from different centuries.

  2. Normal tissue tolerance to external beam radiation therapy: Esophagus

    International Nuclear Information System (INIS)

    Bera, G.; Pointreau, Y.; Denis, F.; Dupuis, O.; Orain, I.; Crehange, G.

    2010-01-01

    The esophagus is a musculo-membranous tube through which food passes from the pharynx to the stomach. Due to its anatomical location, it can be exposed to ionizing radiation in many external radiotherapy indications. Radiation-induced esophageal mucositis is clinically revealed by dysphagia and odynophagia, and usually begins 3 to 4 weeks after the start of radiation treatment. With the rise of multimodality treatments (e.g., concurrent chemoradiotherapy, dose escalation and accelerated fractionation schemes), esophageal toxicity has become a significant dose-limiting issue. Understanding the predictive factors of esophageal injury may improve the optimal delivery of treatment plans. It may help to minimize the risks, hence increasing the therapeutic ratio. Based on a large literature review, our study describes both early and late radiation-induced esophageal injuries and highlights some of the predictive factors for cervical and thoracic esophagus toxicity. These clinical and dosimetric parameters are numerous but none is consensual. The large number of dosimetric parameters strengthens the need of an overall analysis of the dose/volume histograms. The data provided is insufficient to recommend their routine use to prevent radiation-induced esophagitis. Defining guidelines for the tolerance of the esophagus to ionizing radiation remains essential for a safe and efficient treatment. (authors)

  3. External beam radiotherapy for carcinoma of the prostate

    International Nuclear Information System (INIS)

    Sagerman, R.H.; Chun, H.C.; King, G.A.; Chung, C.T.; Dalal, P.S.

    1989-01-01

    Five hundred nineteen patients with prostate cancer were seen in the Radiation Oncology Division of the State University of New York (SUNY) Health Science Center, Syracuse, New York, between 1969 and 1981. The results for the 239 patients treated with radical intent are reported here. All patients received 60 to 70 Gy to the prostate with megavoltage beam irradiation; 142 with a small field (10 X 10 cm) 360 degrees rotational technique for Stage A, B, or C disease and 69 with a four-field pelvic brick technique (followed by a boost to the prostate) for Stage A through C and D1 disease. Twenty-eight patients were treated postoperatively for residual disease after radical prostatectomy or for recurrent tumor. The minimum follow-up time was 5 years. Actuarial 5-year and 7-year survival rates for Stage A (n = 34), B (n = 100), C (n = 63), and D1 (n = 14) were 91% and 76%, 86% and 75%, 67% and 40%, and 46% and 36%, respectively. The corresponding 5-year and 7-year relapse-free survival rates were 72% and 65%, 77% and 60%, 46% and 28%, and 38% and 25%. The local tumor control rates at 5 years were 91%, 85%, 77%, and 62% for Stage A, B, C, and D1, respectively. In our experience, there was no significant difference in relapse-free survival rates for patients who underwent transurethral resection (TURP) versus those who did not (67% versus 78% for Stage B [P greater than 0.25] and 38% versus 47% for Stage C [P greater than 0.25], respectively). Also there was no significant difference in relapse-free survival rates between large and small field techniques (64% versus 77% for Stage B [P greater than 0.25] and 56% versus 41% for Stage C [P greater than 0.25], respectively). The 5-year and 7-year actuarial survival rates were 90% and 71%, respectively, for the 15 patients with residual tumor and 58% and 33%, respectively, for the 13 patients treated for postprostatectomy recurrence

  4. Flexural Behavior of RC Members Using Externally Bonded Aluminum-Glass Fiber Composite Beams

    Directory of Open Access Journals (Sweden)

    Ki-Nam Hong

    2014-03-01

    Full Text Available This study concerns improvement of flexural stiffness/strength of concrete members reinforced with externally bonded, aluminum-glass fiber composite (AGC beams. An experimental program, consisting of seven reinforced concrete slabs and seven reinforced concrete beams strengthened in flexure with AGC beams, was initiated under four-point bending in order to evaluate three parameters: the cross-sectional shape of the AGC beam, the glass fiber fabric array, and the installation of fasteners. The load-deflection response, strain distribution along the longitudinal axis of the beam, and associated failure modes of the tested specimens were recorded. It was observed that the AGC beam led to an increase of the initial cracking load, yielding load of the tension steels and peak load. On the other hand, the ductility of some specimens strengthened was reduced by more than 50%. The A-type AGC beam was more efficient in slab specimens than in beam specimens and the B-type was more suitable for beam specimens than for slabs.

  5. Nonlinear Analysis of External Prestressed Reinforced Concrete Beams with BFRP and CFRP

    Directory of Open Access Journals (Sweden)

    Haleem K. Hussain

    2017-05-01

    Full Text Available The traditional strengthening methods for concrete structure (girders, beams, columns…. consuming time and could be an economical, a new modern repair methods using the Carbon Fiber Reinforced Polymers (CFRP and Basalt Fiber Reinforced Polymer (BFRP as a laminate strips or bars,and considered a competitive solution that will increase the life-cycle of repaired structures. This study investigated the strengthen reinforced concrete girder. Nonlinear analysis have been adopted to the models using FEM analysis (ANSYS to simulate the theoretical results compared with experimental results.Using finite element packages, more efficient and better analyses can be made to fully understand the response of individual structural components and their contribution to a structure as a whole.Three type of material are used in this study as an external prestressed wire (steel, CFRP and BFRP. The prestressed beam is modeled as simply supported beam with two concentrated point load. The results showed that all tested strengthening beam increased the load carryingcapacity of the beams depend on prestressing force. Obtained Result was compared for different type of beam.This study also was enlarged to include using CFRP and BFRPbarwhich are light weight and moredurable, lead to ease of handling and maintenance. The research conducted analytical work to evaluate the effectiveness of concrete beams reinforced normally by the use of CFRP and BFRP bars. The results showed a significant gain in the beam’s ultimate capacities using CFRP bars comparing with beam reinforced with BFRP bar and reference beam

  6. Implementation of a system for external audits beam radiation therapy in terms of reference no

    International Nuclear Information System (INIS)

    Alonso Samper, Jose Luis; Dominguez, Lourdes; Alert Silva, Jose; Alfonso Laguardia, Rodolfo; Larrinaga Cortina, Eduardo; Garcia Yip, Fernando; Rodriguez Machado, Jorge; Morales Lopez, Jorge Luis; Silvestre Patallo, Ileana

    2009-01-01

    This paper presents our experience in implementing a external audit system for radiotherapy beam in no reference conditions with the use of CIRS and a summary of the measurements with him made.This paper presents our experience in implementing a external audit system for radiotherapy beam in no reference conditions with the use of CIRS and a summary of the measurements with him made. Centers were audited with external beam high-energy Co-60, 6 MV and 15 MV and were considered 4 treatment planning systems (TPS): AMEPLAN, Theraplan Plus, Precise Plan and MIRS to calculate doses prescribed in each test case. All measurements were acquired by the audit team using the anthropomorphic phantom CIRS, Semiflex chamber PTW 31010 and PTW electrometer STATES. The implementation and development of the external audits of beams radiotherapy in terms of 'no reference' has brought an improvement in both clinical aspects of treatment and the radiation safety and the quality control, has given us greater confidence and for this reason we believe has become essential. (Author)

  7. External beam radiation for retinoblastoma: Results, patterns of failure, and a proposal for treatment guidelines

    International Nuclear Information System (INIS)

    Hernandez, J. Carlos; Brady, Luther W.; Shields, Jerry A.; Shields, Carol L.; Potter, Patrick de; Karlsson, Ulf L.; Markoe, Arnold M.; Amendola, Beatriz E.; Singh, Arun

    1996-01-01

    Purpose: To analyze treatment results and patterns of failure following external beam radiation for retinoblastoma and propose treatment guidelines according to specific clinical variables. Methods and Materials: We analyzed 27 patients (34 eyes) with retinoblastoma who received external beam radiation as initial treatment at Hahnemann University Hospital from October 1980 to December 1991 and have been followed for at least 1 year. Of the 34 eyes, 14 were Groups I-II (Reese-Ellsworth classification), 7 were Group III, and 13 were Groups IV-V. Doses ranged from 34.5-49.5 Gy (mean 44.3 Gy, median 45 Gy) in 1.5-2.0 Gy fractions generally delivered through anterior and lateral wedged pair fields. Results: At a mean follow up of 35.2 months (range 12-93 months), local tumor control was obtained in 44% (15 out of 34) of eyes with external beam radiation alone. Salvage therapy (plaque brachytherapy, cryotherapy, and/or photocoagulation) controlled an additional 10 eyes (29.5%), so that overall ocular survival has been 73.5%. Local tumor control with external beam radiotherapy alone was obtained in 78.5% (11 out of 14) of eyes in Groups I-II, but in only 20% (4 out of 20) of eyes in Groups III-V. A total of 67 existing tumors were identified prior to treatment in the 34 treated eyes and local control with external beam radiation alone was obtained in 87% (46 out of 53) of tumors measuring 15 mm or less and in 50% (7 out of 14) of tumors measuring more than 15 mm. When analyzing patterns of failure in the 19 eyes that relapsed, a total of 28 failure sites were identified and consisted of progression of vitreous seeds in seven instances (25% of failure sites) recurrences from previously existing tumors in 10 instances (36% of failure sites) and development of new tumors in previously uninvolved retina in 11 instances (39% of failure sites). Conclusions: 1) We find that external beam radiation to a dose of 45 Gy in fractions of 1.5 to 2.0 Gy provides adequate tumor control

  8. Shear Strengthening of RC Deep Beam Using Externally Bonded GFRP Fabrics

    Science.gov (United States)

    Kumari, A.; Patel, S. S.; Nayak, A. N.

    2018-06-01

    This work presents the experimental investigation of RC deep beams wrapped with externally bonded Glass Fibre Reinforced Polymer (GFRP) fabrics in order to study the Load versus deflection behavior, cracking pattern, failure modes and ultimate shear strength. A total number of five deep beams have been casted, which is designed with conventional steel reinforcement as per IS: 456 (Indian standard plain and reinforced concrete—code for practice, Bureau of Indian Standards, New Delhi, 2000). The spans to depth ratio for all RC deep beams have been kept less than 2 as per the above specification. Out of five RC deep beams, one without retrofitting serves as a reference beam and the rest four have been wrapped with GFRP fabrics in multiple layers and tested with two point loading condition. The first cracking load, ultimate load and the shear contribution of GFRP to the deep beams have been observed. A critical discussion is made with respect to the enhancement of the strength, behaviour and performance of retrofitted deep beams in comparison to the deep beam without GFRP in order to explore the potential use of GFRP for strengthening the RC deep beams. Test results have demonstrated that the deep beams retrofitted with GFRP shows a slower development of the diagonal cracks and improves shear carrying capacity of the RC deep beam. A comparative study of the experimental results with the theoretical ones predicted by various researchers available in the literatures has also been presented. It is observed that the ultimate load of the beams retrofitted with GFRP fabrics increases with increase of number of GFRP layers up to a specific number of layers, i.e. 3 layers, beyond which it decreases.

  9. 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.

  10. Beam-centric algorithm for pretreatment patient position correction in external beam radiation therapy

    International Nuclear Information System (INIS)

    Bose, Supratik; Shukla, Himanshu; Maltz, Jonathan

    2010-01-01

    Purpose: In current image guided pretreatment patient position adjustment methods, image registration is used to determine alignment parameters. Since most positioning hardware lacks the full six degrees of freedom (DOF), accuracy is compromised. The authors show that such compromises are often unnecessary when one models the planned treatment beams as part of the adjustment calculation process. The authors present a flexible algorithm for determining optimal realizable adjustments for both step-and-shoot and arc delivery methods. Methods: The beam shape model is based on the polygonal intersection of each beam segment with the plane in pretreatment image volume that passes through machine isocenter perpendicular to the central axis of the beam. Under a virtual six-DOF correction, ideal positions of these polygon vertices are computed. The proposed method determines the couch, gantry, and collimator adjustments that minimize the total mismatch of all vertices over all segments with respect to their ideal positions. Using this geometric error metric as a function of the number of available DOF, the user may select the most desirable correction regime. Results: For a simulated treatment plan consisting of three equally weighted coplanar fixed beams, the authors achieve a 7% residual geometric error (with respect to the ideal correction, considered 0% error) by applying gantry rotation as well as translation and isocentric rotation of the couch. For a clinical head-and-neck intensity modulated radiotherapy plan with seven beams and five segments per beam, the corresponding error is 6%. Correction involving only couch translation (typical clinical practice) leads to a much larger 18% mismatch. Clinically significant consequences of more accurate adjustment are apparent in the dose volume histograms of target and critical structures. Conclusions: The algorithm achieves improvements in delivery accuracy using standard delivery hardware without significantly increasing

  11. Target volume delineation in external beam partial breast irradiation: Less inter-observer variation with preoperative- compared to postoperative delineation

    International Nuclear Information System (INIS)

    Leij, Femke van der; Elkhuizen, Paula H.M.; Janssen, Tomas M.; Poortmans, Philip; Sangen, Maurice van der; Scholten, Astrid N.; Vliet-Vroegindeweij, Corine van; Boersma, Liesbeth J.

    2014-01-01

    The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of twenty-four breast cancer patients

  12. Target volume delineation in external beam partial breast irradiation: less inter-observer variation with preoperative- compared to postoperative delineation

    NARCIS (Netherlands)

    Leij, F. van der; Elkhuizen, P.H.M.; Janssen, T.M.; Poortmans, P.M.P.; Sangen, M. van der; Scholten, A.N.; Vliet-Vroegindeweij, C. van; Boersma, L.J.

    2014-01-01

    The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of

  13. Possibilities and conditions of applying PIXE analysis with external proton beam

    International Nuclear Information System (INIS)

    Potocek, V.

    1989-01-01

    The technical and methodological prerequisites are summed up for the use of the PIXE method with an external proton beam. The method is suitable for the preliminary analysis of unknown samples prior to the choice of the best suited analytical method, for the nondestructive analysis of rare samples such as unique works of art, of small amounts of materials which are difficult to access, etc., as well as for calibration and comparing analyses. As for the operators the application of the PIXE method with external proton beam assumes the availability of accelerator operating time, minimization of the length of exposure of the targets, optimization of parameters of the exciting beam and automation of the whole process. Attention is also devoted to technical provisions and organization of laboratory work. The design is described of an analytical unit using the PIXE method with external proton beam, and it is stated that the Van de Graaff accelerator at the Institute of Nuclear Physics in Rez near Prague could be used for the purpose. (Z.M.). 6 refs

  14. Influence of external beam technique and brachytherapy quality assurance on the side effects in the combined external beam- and brachytherapy treatment of local advanced prostate cancer

    International Nuclear Information System (INIS)

    Kovacs, G.; Galalae, R.; Wirth, B.; Bertermann, H.; Wilhelm, R.; Kohr, P.; Kimmig, B.

    1996-01-01

    Transrectal ultrasound(TRUS) guided HDR implantation of the prostate has been established at the Kiel University by Bertermann and Brix in 1986 and there are to date 179 (T1b-T3 No Mo) patients treated in a combined modality. The dose for the implant was 2x 15 Gy on the capsule of the prostate in 14-20 days. For local and regional lymph nodes 20 Gy external beam therapy (AP-PA pelvic portals), 20 Gy with an individual transmission block (100% for subclinical disease, 70% and 50% according to the implant dosimetry for the prostate) and 10 Gy small volume irradiation for the prostate was applied, conventional fractioned. Total dose after the therapy 70 Gy for the prostate and 50 Gy for the subclinical disease in 6-7 weeks. As a quality control method we use since 1991 in vivo dosimetry on the medial rectum wall as well as in the prostatic part of the urethra. Regular follow-up 3-118 months after therapy (median 55) with PSA, digital rectal examination, control TRUS with volumetry (after one year with biopsy) and bone scan. There were no major early side effects within the first three months. Proctitis till 1991 with a duration up to 12 months 49%, prolonging more than one year in 23 %, (total proctitis 72.6%). Dysuria in up to 12 months 30 %, long lasting 30% (total number of dysuria 60 %). Erectile dysfunction in 56 %. Because of the number of the side effects 1991 we changed the external beam technique: instead of the biaxial arch therapy the AP-PA portals, and reduced irradiated volume (from 6480 cm 3 to 5040 cm 3 ). We introduced instead of the small volume arch therapy for 10 Gy external boost the box-technique with shielding the back part of the rectum and the upper part of the bladder resulting additional volume reduction. Through the 15 Gy HDR brachytherapy dose on the prostate capsule there are up to 8 Gy on the medial rectal wall, measured by in vivo dosimetry. This dose could not be responsible for the high number of side effects (see gynecological

  15. Recurrent malignant pilomatrixoma invading the cranial cavity: improved local control with adjuvant radiation

    International Nuclear Information System (INIS)

    Aherne, N. J.; Fitzpatrick, D. A.; Armstrong, J. G.; Gibbons, D.; Collins, C. D.

    2009-01-01

    Full text: We report the case of a 41-year-old mentally retarded male with recurrent pilomatrix carcinoma of the occipital region which invaded the occipital bone, left cerebellum and left temporal lobe. At his initial presentation the patient had a craniotomy and subtotal excision of the lesion with positive margins. He received no adjuvant therapy. After an early intracranial recurrence he had subtotal debulking and was referred for external beam radiotherapy. At 27 months follow-up after adjuvant external beam radiotherapy the intracranial component has not progressed and the patient remains clinically well

  16. External post-operational checks for the LHC beam dumping system

    International Nuclear Information System (INIS)

    Magnin, N.; Baggiolini, V.; Carlier, E.; Goddard, B.; Gorbonosov, R.; Khasbulatov, D.; Uythoven, J.; Zerlauth, M.

    2012-01-01

    The LHC Beam Dumping System (LBDS) is a critical part of the LHC machine protection system. After every LHC beam dump action the various signals and transient data recordings of the beam dumping control systems and beam instrumentation measurements are automatically analysed by the external Post-Operational Checks (XPOC) system to verify the correct execution of the dump action and the integrity of the related equipment. This software system complements the LHC machine protection hardware, and has to ascertain that the beam dumping system is 'as good as new' before the start of the next operational cycle. This is the only way by which the stringent reliability requirements can be met. The XPOC system has been developed within the framework of the LHC 'Post-Mortem' system, allowing highly dependable data acquisition, data archiving, live analysis of acquired data and replay of previously recorded events. It is composed of various analysis modules, each one dedicated to the analysis of measurements coming from specific equipment. This paper describes the global architecture of the XPOC system and gives examples of the analyses performed by some of the most important analysis modules. It explains the integration of the XPOC into the LHC control infrastructure along with its integration into the decision chain to allow proceeding with beam operation. Finally, it discusses the operational experience with the XPOC system acquired during the first years of LHC operation, and illustrates examples of internal system faults or abnormal beam dump executions which it has detected. (authors)

  17. The target volume concept at the recording of external beam radiotherapy

    International Nuclear Information System (INIS)

    Quast, U.; Glaeser, L.

    1981-01-01

    With the aim of complete, exact and reproducible manual recording and documentation of external beam radiotherapy a concept is proposed providing treatment planning and recording related to space and time for target volumes of different order corresponding to Ist, IInd or IIIrd part of treatment course, regarding all dose limiting organs at risk. The record consists of the dosage plan for medical treatment planning, the treatment plan for physical dose distribution planning and the treatment record of absorbed doses delivered as well as a checklist for patient and machine set-up, and labels for intended actions during treatment development. A clear arrangement of the record form in logical order was found, demanding exact specification of target(s) and beam(s) and their relation in space and time; asking for verbal and graphical description of target volumes, organs at risk, patient positioning, beam portals and dose reference points in terms of patients' anatomy; emphasizing the most important medical data by marked areas and leaving enough empty space for additional data, remarks or comments. During several years of clinical use these record forms proved to be suitable for all cases of external beam therapy, for complex situations of target volumes and treatment-scheduling, for all treatment techniques and radiation qualities and for all ways of physical treatment planning. They can be extended to automatic treatment verification, monitoring and recording as well as to the application of in-vivo-measurements of absorbed doses. (orig.) [de

  18. Development of an external beam nuclear microprobe on the Aglae facility of the Louvre museum

    Energy Technology Data Exchange (ETDEWEB)

    Calligaro, T.; Dran, J.-C. E-mail: dran@culture.fr; Ioannidou, E.; Moignard, B.; Pichon, L.; Salomon, J

    2000-03-01

    The external beam line of our facility has been recently equipped with the focusing system previously mounted on a classical nuclear microprobe. When using a 0.1 {mu}m thick Si{sub 3}N{sub 4} foil for the exit window and flowing helium on the sample under analysis, a beam spot as small as 10 {mu}m is attainable at a distance of 3 mm from the window. Elemental micromapping is performed by mechanical scanning. An electronic device has been designed which allows XY scanning by moving the sample under the beam by steps down to 0.1 {mu}m. Beam monitoring is carried out by means of the weak X-ray signal emitted by the exit foil and detected by a specially designed Si(Li) detector cooled by Peltier effect. The characteristics of external beams of protons and alpha particles are evaluated by means of resonance scanning and elemental mapping of a grid. An example of application is presented, dealing with elemental micro-mapping of inclusions in gemstones.

  19. Breast conserving treatment of breast carcinoma T2 ({<=} 4 cm) and T3 by neoadjuvant chemotherapy, quadrantectomy, high dose rate brachytherapy as a boost, external beam radiotherapy and adjuvant chemotherapy: local control and overall survival analysis; Tratamento conservador do cancer de mama T2 ({<=} 4 cm) e T3 por quimioterapia neoadjuvante, quadrantectomia, braquiterapia com alta taxa de dose como reforco de dose, teleterapia complementar e quimioterapia adjuvante: analise de controle local e sobrevida global

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Celia Regina; Miziara Filho, Miguel Abrao; Fogaroli, Ricardo Cesar; Baraldi, Helena Espindola; Pellizzon, Antonio Cassio Assis; Pelosi, Edilson Lopes [Instituto do Cancer Dr. Arnaldo Vieira de Carvalho (ICAVC), Sao Paulo, SP (Brazil). Servico de Radioterapia], e-mail: celiarsoares@terra.com.br; Fristachi, Carlos Elias [Instituto do Cancer Dr. Arnaldo Vieira de Carvalho (ICAVC), Sao Paulo, SP (Brazil). Servico de Onco-Ginecologia e Mastologia; Paes, Roberto Pinto [Instituto do Cancer Dr. Arnaldo Vieira de Carvalho (ICAVC), Sao Paulo, SP (Brazil)

    2008-12-15

    Objective: to assess the treatment of breast cancer T2 ({<=} 4 cm) and T3 through neoadjuvant chemotherapy, quadrantectomy and high dose rate brachytherapy as a boost, complementary radiotherapy and adjuvant chemotherapy, considering local control and overall survival. Material and method: this clinical prospective descriptive study was based on the evaluation of 88 patients ranging from 30 to 70 years old, with infiltrating ductal carcinoma, clinical stage IIb and IIIa, responsive to the neoadjuvant chemotherapy, treated from June/1995 to December/2006. Median follow-up was 58 months. Using clinical methods the tumor was evaluated before and after three or four cycles of chemotherapy based on anthracyclines. Overall survival and local control were assessed according to Kaplan-Meier methodology. Results: Local control and overall survival in five years were 90% and 73.5%, respectively. Conclusion: local control and overall survival were comparable to other forms of treatment. (author)

  20. An assessment of effective dose to staff in external beam radiotherapy

    International Nuclear Information System (INIS)

    Rawlings, D.J.; Nicholson, L.

    1997-01-01

    Radiation safety in external beam radiotherapy is governed by national legislation. Annual doses recorded by radiographers and others associated with external beam radiotherapy are typically much lower than the relevant dose limit. However, it is possible that larger doses might be received as a result of an accidental irradiation. In the event of a significant exposure resulting in a dose at or near a relevant dose limit, an accurate conversion has to be made from the dose meter reading to the limiting quantity. A method was devised to demonstrate ratios of effective dose to personal dose equivalent which might be anticipated in the even of an individual other than the patient being irradiated within a radiotherapy treatment room consisting of a linear accelerator. The variation of ratios obtained under different conditions is discussed. (author)

  1. Radiation optic neuropathy after external beam radiation therapy for acromegaly: report of two cases

    International Nuclear Information System (INIS)

    Bergh, Alfons C.M. van den; Hoving, Marjanke A.; Links, Thera P.; Dullaart, Robin P.F.; Ranchor, Adelita V.; Weeme, Cees A. ter; Canrinus, Alof A.; Szabo, Ben G.; Pott, Jan-Willem R.

    2003-01-01

    For diagnosing radiation optic neuropathy (RON) ophthalmological and imaging data were evaluated from 63 acromegalic patients, irradiated between 1967 and 1998. Two patients developed RON: one patient in one optic nerve 10 years and another patient in both optic nerves 5 months after radiation therapy. RON is a rare complication after external beam radiation therapy for acromegaly, which can occur after a considerable latency period

  2. Controversies in external beam and high dose rate brachytherapy of oesophageal cancer

    International Nuclear Information System (INIS)

    Sur, R.K.; Levin, V.C.; Malas, Simon; Donde, Bernard

    1994-01-01

    Various controversies in the treatment of oesophageal carcinoma with external beam radiotherapy and high dose rate intracavitary irradiation have been reviewed. Conflicting results from different parts of the world has made it difficult to optimize the radiation dose that may give the best results. More studies and longer follow-up are needed before a definite conclusion can be made on the optimization of dose. (author). 18 refs., 2 tabs

  3. T2-weighted endorectal magnetic resonance imaging of prostate cancer after external beam radiation therapy

    International Nuclear Information System (INIS)

    Westphalen, Antonio C.; Kurhanewicz, John; Cunha, Rui M.G.; Hsu, I-Chow; Kornak, John; Zhao, Shoujun; Coakley, Fergus V.

    2009-01-01

    Purpose: To retrospectively determine the accuracy of T2-weighted endorectal MR imaging in the detection of prostate cancer after external beam radiation therapy and to investigate the relationship between imaging accuracy and time since therapy. Materials and Methods: Institutional review board approval was obtained and the study was HIPPA compliant. We identified 59 patients who underwent 1.5 Tesla endorectal MR imaging of the prostate between 1999 and 2006 after definitive external beam radiation therapy for biopsy-proven prostate cancer. Two readers recorded the presence or absence of tumor on T2-weighted images. Logistic regression and Fisher's exact tests for 2x2 tables were used to determine the accuracy of imaging and investigate if accuracy differed between those imaged within 3 years of therapy (n = 25) and those imaged more than 3 years after therapy (n = 34). Transrectal biopsy was used as the standard of reference for the presence or absence of recurrent cancer. Results: Thirty-four of 59 patients (58%) had recurrent prostate cancer detected on biopsy. The overall accuracy of T2-weighted MR imaging in the detection cancer after external beam radiation therapy was 63% (37/59) for reader 1 and 71% for reader 2 (42/59). For both readers, logistic regression showed no difference in accuracy between those imaged within 3 years of therapy and those imaged more than 3 years after therapy (p = 0.86 for reader 1 and 0.44 for reader 2). Conclusion: T2-weighted endorectal MR imaging has low accuracy in the detection of prostate cancer after external beam radiation therapy, irrespective of the time since therapy. (author)

  4. PIXE/PIGE characterisation of emeralds using an external micro-beam

    International Nuclear Information System (INIS)

    Calligaro, T.; Dran, J.-C.; Poirot, J.-P.; Querre, G.; Salomon, J.; Zwaan, J.C.

    2000-01-01

    A large collection of emeralds of various occurrences has been analysed by PIXE/PIGE in view to establish a compositional database. Major elements (Be, Si, Al) and trace elements (Li, F, Na, Mg, Ca, Rb, Cs and transition metals) are determined using an external 3 MeV proton micro-beam. Elemental micro-mapping permits to select the useful provenance tracers. This database was applied to infer the origin of several ancient emeralds set on historical jewels

  5. Dosimetric comparison of partial and whole breast external beam irradiation in the treatment of early stage breast cancer

    International Nuclear Information System (INIS)

    Kim, Yongbok; Parda, David S.; Trombetta, Mark G.; Colonias, Athanasios; Werts, E. Day; Miller, Linda; Miften, Moyed

    2007-01-01

    A dosimetric comparison was performed on external-beam three-dimensional conformal partial breast irradiation (PBI) and whole breast irradiation (WBI) plans for patients enrolled in the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39/Radiation Therapy Oncology Group (RTOG) 0413 protocol at our institution. Twenty-four consecutive patients were treated with either PBI (12 patients) or WBI (12 patients). In the PBI arm, the lumpectomy cavity was treated to a total dose of 38.5 Gy at 3.85 Gy per fraction twice daily using a four-field noncoplanar beam setup. A minimum 6 h interval was required between fractions. In the WBI arm, the whole breast including the entirety of the lumpectomy cavity was treated to a total dose of 50.4 Gy at 1.8 Gy per fraction daily using opposed tangential beams. The lumpectomy cavity volume, planning target volume for evaluation (PTV E VAL), and critical structure volumes were contoured for both the PBI and WBI patients. Dosimetric parameters, dose volume histograms (DVHs), and generalized equivalent uniform dose (gEUD) for target and critical structures were compared. Dosimetric results show the PBI plans, compared to the WBI plans, have smaller hot spots in the PTV E VAL (maximum dose: 104.2% versus 110.9%) and reduced dose to the ipsilateral breast (V50: 48.6% versus 92.1% and V100: 10.2% versus 50.5%), contralateral breast (V3: 0.16% versus 2.04%), ipsilateral lung (V30: 5.8% versus 12.7%), and thyroid (maximum dose: 0.5% versus 2.0%) with p values ≤0.01. However, similar dose coverage of the PTV E VAL (98% for PBI and 99% for WBI, on average) was observed and the dose difference for other critical structures was clinically insignificant in both arms. The gEUD data analysis showed the reduction of dose to the ipsilateral breast and lung, contralateral breast and thyroid. In addition, preliminary dermatologic adverse event assessment data suggested reduced skin toxicity for patients treated with the PBI technique

  6. 3D FE Analysis of RC Beams Externally Strengthened with SRG/SRP Systems

    Directory of Open Access Journals (Sweden)

    Francesco Bencardino

    2016-05-01

    Full Text Available The purpose of this study is to evaluate, through a nonlinear Finite Element (FE analysis, the structural behavior of Reinforced Concrete (RC beams externally strengthened by using Steel Reinforced Grout (SRG and Steel Reinforced Polymer (SRP systems. The parameters taken into account were the external strengthening configuration, with or without U-wrap end anchorages, as well as the strengthening materials. The numerical simulations were carried out by using a three-dimensional (3D FE model. The linear and nonlinear behavior of all materials was modeled by appropriate constitutive laws and the connection between concrete substrate and external reinforcing layer was simulated by means of cohesive surfaces with appropriate bond-slip laws. In order to overcome convergence difficulties, to simulate the quasi-static response of the strengthened RC beams, a dynamic approach was adopted. The numerical results in terms of load-displacement curves, failure modes, and load and strain values at critical stages were validated against some experimental data. As a result, the proposed 3D FE model can be used to predict the structural behavior up to ultimate stage of similar strengthened beams without carrying out experimental tests.

  7. MO-A-BRB-03: Integration Issues in Electronic Charting for External Beam Therapy

    International Nuclear Information System (INIS)

    Sutlief, S.

    2015-01-01

    The process of converting to an electronic chart for radiation therapy can be daunting. It requires a dedicated committee to first research and choose appropriate software, to review the entire documentation policy and flow of the clinic, to convert this system to electronic form or if necessary, redesign the system to more easily conform to the electronic process. Those making the conversion and those who already use electronic charting would benefit from the shared experience of those who have been through the process in the past. Therefore TG262 was convened to provide guidance on electronic charting for external beam radiation therapy and brachytherapy. This course will present the results of an internal survey of task group members on EMR practices in External Beam Radiation Therapy as well as discuss important issues in EMR development and structure for both EBRT and brachytherapy. Learning Objectives: Be familiarized with common practices and pitfalls in development and maintenance of an electronic chart in Radiation Oncology Be familiarized with important issues related to electronic charting in External Beam Radiation Therapy Be familiarized with important issues related to electronic charting in Brachytherapy

  8. Evaluation of GafChromic EBT prototype B for external beam dose verification

    International Nuclear Information System (INIS)

    Todorovic, M.; Fischer, M.; Cremers, F.; Thom, E.; Schmidt, R.

    2006-01-01

    The capability of the new GafChromic EBT prototype B for external beam dose verification is investigated in this paper. First the general characteristics of this film (dose response, postirradiation coloration, influence of calibration field size) were derived using a flat-bed scanner. In the dose range from 0.1 to 8 Gy, the sensitivity of the EBT prototype B film is ten times higher than the response of the GafChromic HS, which so far was the GafChromic film with the highest sensitivity. Compared with the Kodak EDR2 film, the response of the EBT is higher by a factor of 3 in the dose range from 0.1 to 8 Gy. The GafChromic EBT almost does not show a temporal growth of the optical density and there is no influence of the chosen calibration field size on the dose response curve obtained from this data. A MatLab program was written to evaluate the two-dimensional dose distributions from treatment planning systems and GafChromic EBT film measurements. Verification of external beam therapy (SRT, IMRT) using the above-mentioned approach resulted in very small differences between the planned and the applied dose. The GafChromic EBT prototype B together with the flat-bed scanner and MatLab is a successful approach for making the advantages of the GafChromic films applicable for verification of external beam therapy

  9. Unified model to predict flexural shear behavior of externally bonded RC beams

    International Nuclear Information System (INIS)

    Colotti, V.; Spadea, G.; Swamy, R.N.

    2006-01-01

    Structural strengthening with externally bonded reinforcement is now recognized as a cost-effective, structurally sound and practically efficient method of rehabilitating deteriorating and damaged reinforced concrete beams. There is now an urgent need to develop a sound engineering basis which can predict the failure loads of all such strengthened beams in a reliable and consistent manner. Existing models to predict the behavior at ultimate of strengthened beams suffer from many limitations and weaknesses. This paper presents a unified global model, based on the Strut-and-Tie approach, to predict the failure loads of reinforced concrete beams strengthened for flexure and/or shear. This structural model is based on rational engineering principles, considers all the possible failure modes, and incorporates the load transfer mechanism bond to reflect the debonding phenomena which has a dominant influence on the failure process of plated beams. The model is validated against about 200 strengthened beam test reported in the literature and failing in flexure and/or shear, involving a large number of structural variables and steel, carbon and glass fiber reinforced polymer laminates as reinforcing medium. (author)

  10. Pilot Quality Control Program for Audit RT External Beams at Mexican Hospitals

    International Nuclear Information System (INIS)

    Alvarez R, J T; Tovar M, V M

    2008-01-01

    A pilot quality control program for audit 18 radiotherapy RT external beams at 13 Mexican hospitals is described--for eleven 60 Co beams and seven photon beams of 6, 10 and 15 MV from accelerators. This program contains five parts: a) Preparation of the TLD-100 powder: washing, drying and annealing (one hour 400 deg. C plus 24 hrs 80 deg. C). b) Sending two IAEA type capsules to the hospitals for irradiation at the hospital to a nominal D W = 2 Gy·c) Preparation at the SSDL of ten calibration curves CC in the range of 0.5 Gy to 6 Gy in terms of absorbed dose to water D W for 60 Co with traceability to primary laboratory NRC (Canada), according to a window irradiation: 26/10/2007-7/12/2007. d) Reading all capsules that match their hospital time irradiation and the SSDL window irradiation. f) Evaluation of the Dw imparted by the hospitals

  11. Pilot Quality Control Program for Audit RT External Beams at Mexican Hospitals

    Science.gov (United States)

    Álvarez R., J. T.; Tovar M., V. M.

    2008-08-01

    A pilot quality control program for audit 18 radiotherapy RT external beams at 13 Mexican hospitals is described—for eleven 60 Co beams and seven photon beams of 6, 10 and 15 MV from accelerators. This program contains five parts: a) Preparation of the TLD-100 powder: washing, drying and annealing (one hour 400 °C plus 24 hrs 80 °C). b) Sending two IAEA type capsules to the hospitals for irradiation at the hospital to a nominal DW = 2 Gy ṡ c ) Preparation at the SSDL of ten calibration curves CC in the range of 0.5 Gy to 6 Gy in terms of absorbed dose to water DW for 60 Co with traceability to primary laboratory NRC (Canada), according to a window irradiation: 26/10/2007-7/12/2007. d) Reading all capsules that match their hospital time irradiation and the SSDL window irradiation. f) Evaluation of the Dw imparted by the hospitals.

  12. Experimental assessment of out-of-field dose components in high energy electron beams used in external beam radiotherapy.

    Science.gov (United States)

    Alabdoaburas, Mohamad M; Mege, Jean-Pierre; Chavaudra, Jean; Bezin, Jérémi Vũ; Veres, Atilla; de Vathaire, Florent; Lefkopoulos, Dimitri; Diallo, Ibrahima

    2015-11-08

    The purpose of this work was to experimentally investigate the out-of-field dose in a water phantom, with several high energy electron beams used in external beam radiotherapy (RT). The study was carried out for 6, 9, 12, and 18 MeV electron beams, on three different linear accelerators, each equipped with a specific applicator. Measurements were performed in a water phantom, at different depths, for different applicator sizes, and off-axis distances up to 70 cm from beam central axis (CAX). Thermoluminescent powder dosimeters (TLD-700) were used. For given cases, TLD measurements were compared to EBT3 films and parallel-plane ionization chamber measurements. Also, out-of-field doses at 10 cm depth, with and without applicator, were evaluated. With the Siemens applicators, a peak dose appears at about 12-15 cm out of the field edge, at 1 cm depth, for all field sizes and energies. For the Siemens Primus, with a 10 × 10 cm(²) applicator, this peak reaches 2.3%, 1%, 0.9% and 1.3% of the maximum central axis dose (Dmax) for 6, 9, 12 and 18 MeV electron beams, respectively. For the Siemens Oncor, with a 10 × 10 cm(²) applicator, this peak dose reaches 0.8%, 1%, 1.4%, and 1.6% of Dmax for 6, 9, 12, and 14 MeV, respectively, and these values increase with applicator size. For the Varian 2300C/D, the doses at 12.5 cm out of the field edge are 0.3%, 0.6%, 0.5%, and 1.1% of Dmax for 6, 9, 12, and 18 MeV, respectively, and increase with applicator size. No peak dose is evidenced for the Varian applicator for these energies. In summary, the out-of-field dose from electron beams increases with the beam energy and the applicator size, and decreases with the distance from the beam central axis and the depth in water. It also considerably depends on the applicator types. Our results can be of interest for the dose estimations delivered in healthy tissues outside the treatment field for the RT patient, as well as in studies exploring RT long-term effects.

  13. Dosimetric comparison of proton and photon three-dimensional, conformal, external beam accelerated partial breast irradiation techniques

    International Nuclear Information System (INIS)

    Kozak, Kevin R.; Katz, Angela; Adams, Judith C.; Crowley, Elizabeth M.; Nyamwanda, Jacqueline A.C.; Feng, Jennifer K.C.; Doppke, Karen P.; DeLaney, Thomas F.; Taghian, Alphonse G.

    2006-01-01

    Purpose: To compare the dosimetry of proton and photon-electron three-dimensional, conformal, external beam accelerated partial breast irradiation (3D-CPBI). Methods and Materials: Twenty-four patients with fully excised, Stage I breast cancer treated with adjuvant proton 3D-CPBI had treatment plans generated using the mixed-modality, photon-electron 3D-CPBI technique. To facilitate dosimetric comparisons, planning target volumes (PTVs; lumpectomy site plus 1.5-2.0 cm margin) and prescribed dose (32 Gy) were held constant. Plans were optimized for PTV coverage and normal tissue sparing. Results: Proton and mixed-modality plans both provided acceptable PTV coverage with 95% of the PTV receiving 90% of the prescribed dose in all cases. Both techniques also provided excellent dose homogeneity with a dose maximum exceeding 110% of the prescribed dose in only one case. Proton 3D-CPBI reduced the volume of nontarget breast tissue receiving 50% of the prescribed dose by an average of 36%. Statistically significant reductions in the volume of total ipsilateral breast receiving 100%, 75%, 50%, and 25% of the prescribed dose were also observed. The use of protons resulted in small, but statistically significant, reductions in the radiation dose delivered to 5%, 10%, and 20% of ipsilateral and contralateral lung and heart. The nontarget breast tissue dosimetric advantages of proton 3D-CPBI were not dependent on tumor location, breast size, PTV size, or the ratio of PTV to breast volume. Conclusions: Compared to photon-electron 3D-CPBI, proton 3D-CPBI significantly reduces the volume of irradiated nontarget breast tissue. Both approaches to accelerated partial breast irradiation offer exceptional lung and heart sparing

  14. Radiotherapy in poor risk patients with stage I cancer of the endometrium: results of not giving external beam radiotherapy.

    Science.gov (United States)

    DeCruze, B; Guthrie, D

    1999-01-01

    Poor prognosis (poorly differentiated and/or deep myometrial invasion) Stage I endometrial cancer can have a relapse rate as high as 50%. Traditionally, most clinical oncologists treat these patients with external beam radiotherapy after surgery but there is no evidence to show that this improves survival. The retrospective study looks at the results of not giving external beam radiotherapy in 25 consecutive patients and compares the results with a group of 13 consecutive patients who did have such treatment. The two groups were comparable with regard to age, degree of differentiation and degree of invasion. Survival was comparable in the two groups. There is no evidence of any obvious decrease in survival from withholding external beam radiotherapy, but this was not a prospective randomized controlled trial. This study illustrates that it is essential that the Medical Research Council ASTEC trial should be supported because this will determine the true place of external beam radiotherapy in such patients.

  15. Dosimetric comparison between intensity modulated brachytherapy versus external beam intensity modulated radiotherapy for cervix cancer: a treatment planning study

    International Nuclear Information System (INIS)

    Subramani, V.; Sharma, D.N.; Jothy Basu, K.S.; Rath, G.K.; Gopishankar, N.

    2008-01-01

    To evaluate the dosimetric superiority of intensity modulated brachytherapy (IMBT) based on inverse planning optimization technique with classical brachytherapy optimization and also with external beam intensity modulated radiotherapy planning technique in patients of cervical carcinoma

  16. ERDA with an external helium ion micro-beam: Advantages and potential applications

    International Nuclear Information System (INIS)

    Calligaro, T.; Castaing, J.; Dran, J.-C.; Moignard, B.; Pivin, J.-C.; Prasad, G.V.R.; Salomon, J.; Walter, P.

    2001-01-01

    Preliminary ERDA experiments at atmospheric pressure have been performed with our external microprobe set-up currently used for the analysis of museum objects by PIXE, RBS and NRA. The objective was to check the feasibility of hydrogen (and deuterium) profiling with an external beam of 3-MeV helium ions. The standard scattering geometry (incident beam at 15 deg. with respect to sample surface and emerging protons or deuterons at 15 deg. in the forward direction) was kept, but the thin foil absorber was replaced by helium gas filling the space between the beam spot and the detector over a distance of about 84 mm. Several standards prepared by ion implantation, with well known H or D depth profiles, were first analysed, which indicated that the analytical capability was as good as under vacuum. A striking feature is the much lower surface peak than under vacuum, a fact that enhances the sensitivity for H analysis near the surface. The same type of measurement was then performed on different materials to show the usefulness of the technique. As a first example, we have checked that the incorporation of H or D into sapphire crystals during mechanical polishing is below the detection limit. Another example is the measurement of the H content in emeralds which can be used as an additional compositional criterion for determining the provenance of emeralds set in museum jewels. The advantages and limitations of our set-up are discussed and several possible applications in the field of cultural heritage are described

  17. Proton external beam in the TANDAR Accelerator; Haz externo de protones en el acelerador TANDAR

    Energy Technology Data Exchange (ETDEWEB)

    Rey, R; Schuff, J A; Perez de la Hoz, A.; Debray, M E; Hojman, D; Kreiner, A J; Kesque, J M; Saint-Martin, G; Oppezzo, O; Bernaola, O A; Molinari, B L; Duran, H A; Policastro, L; Palmieri, M; Ibanez, J; Stoliar, P; Mazal, A; Caraballo, M E; Burlon, A; Cardona, M A; Vazquez, M E; Salfity, M F; Ozafran, M J; Naab, F; Levinton, G; Davidson, M; Buhler, M [Departamento de Fisica, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, C.P. 1650 San Martin, Buenos Aires (Argentina)

    1999-12-31

    An external proton beam has been obtained in the TANDAR accelerator with radiological and biomedical purposes. The protons have excellent physical properties for their use in radiotherapy allowing a very good accuracy in the dose spatial distribution inside the tissue so in the side direction as in depth owing to the presence of Bragg curve. The advantage of the accuracy in the dose localization with proton therapy is good documented (M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983); M.R. Raju, Rad. Res. 145, 391 (1996)). It was obtained external proton beams with energies between 15-25 MeV, currents between 2-10 p A and a uniform transversal sections of 40 mm{sup 2} approximately. It was realized dosimetric evaluations with CR39 and Makrofol foliation. The irradiations over biological material contained experiences In vivo with laboratory animals, cellular and bacterial crops. It was fixed the optimal conditions of position and immobilization of the Wistar rats breeding for the In vivo studies. It was chosen dilutions and sowing techniques adequate for the exposition at the cellular and bacterial crops beam. (Author)

  18. Proton external beam in the TANDAR Accelerator; Haz externo de protones en el acelerador TANDAR

    Energy Technology Data Exchange (ETDEWEB)

    Rey, R.; Schuff, J.A.; Perez de la Hoz, A.; Debray, M.E.; Hojman, D.; Kreiner, A.J.; Kesque, J.M.; Saint-Martin, G.; Oppezzo, O.; Bernaola, O.A.; Molinari, B.L.; Duran, H.A.; Policastro, L.; Palmieri, M.; Ibanez, J.; Stoliar, P.; Mazal, A.; Caraballo, M.E.; Burlon, A.; Cardona, M.A.; Vazquez, M.E.; Salfity, M.F.; Ozafran, M.J.; Naab, F.; Levinton, G.; Davidson, M.; Buhler, M. [Departamento de Fisica, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, C.P. 1650 San Martin, Buenos Aires (Argentina)

    1998-12-31

    An external proton beam has been obtained in the TANDAR accelerator with radiological and biomedical purposes. The protons have excellent physical properties for their use in radiotherapy allowing a very good accuracy in the dose spatial distribution inside the tissue so in the side direction as in depth owing to the presence of Bragg curve. The advantage of the accuracy in the dose localization with proton therapy is good documented (M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983); M.R. Raju, Rad. Res. 145, 391 (1996)). It was obtained external proton beams with energies between 15-25 MeV, currents between 2-10 p A and a uniform transversal sections of 40 mm{sup 2} approximately. It was realized dosimetric evaluations with CR39 and Makrofol foliation. The irradiations over biological material contained experiences In vivo with laboratory animals, cellular and bacterial crops. It was fixed the optimal conditions of position and immobilization of the Wistar rats breeding for the In vivo studies. It was chosen dilutions and sowing techniques adequate for the exposition at the cellular and bacterial crops beam. (Author)

  19. Stability of aerosol droplets in Bessel beam optical traps under constant and pulsed external forces

    International Nuclear Information System (INIS)

    David, Grégory; Esat, Kıvanç; Hartweg, Sebastian; Cremer, Johannes; Chasovskikh, Egor; Signorell, Ruth

    2015-01-01

    We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape

  20. Stability of aerosol droplets in Bessel beam optical traps under constant and pulsed external forces

    Energy Technology Data Exchange (ETDEWEB)

    David, Grégory; Esat, Kıvanç; Hartweg, Sebastian; Cremer, Johannes; Chasovskikh, Egor; Signorell, Ruth, E-mail: rsignorell@ethz.ch [Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich (Switzerland)

    2015-04-21

    We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape.

  1. Stability of aerosol droplets in Bessel beam optical traps under constant and pulsed external forces.

    Science.gov (United States)

    David, Grégory; Esat, Kıvanç; Hartweg, Sebastian; Cremer, Johannes; Chasovskikh, Egor; Signorell, Ruth

    2015-04-21

    We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape.

  2. Stability of aerosol droplets in Bessel beam optical traps under constant and pulsed external forces

    Science.gov (United States)

    David, Grégory; Esat, Kıvanç; Hartweg, Sebastian; Cremer, Johannes; Chasovskikh, Egor; Signorell, Ruth

    2015-04-01

    We report on the dynamics of aerosol droplets in optical traps under the influence of additional constant and pulsed external forces. Experimental results are compared with simulations of the three-dimensional droplet dynamics for two types of optical traps, the counter-propagating Bessel beam (CPBB) trap and the quadruple Bessel beam (QBB) trap. Under the influence of a constant gas flow (constant external force), the QBB trap is found to be more stable compared with the CPBB trap. By contrast, under pulsed laser excitation with laser pulse durations of nanoseconds (pulsed external force), the type of trap is of minor importance for the droplet stability. It typically needs pulsed laser forces that are several orders of magnitude higher than the optical forces to induce escape of the droplet from the trap. If the droplet strongly absorbs the pulsed laser light, these escape forces can be strongly reduced. The lower stability of absorbing droplets is a result of secondary thermal processes that cause droplet escape.

  3. SU-E-T-403: Evaluation of the Beam Performance of a Varian TrueBeam Linear Accelerator Under External Device-Based Gated Delivery Conditions

    International Nuclear Information System (INIS)

    Kobulnicky, K; Pawlak, D; Purwar, A

    2015-01-01

    Purpose: To examine the beam performance of a Varian TrueBeam linear accelerator under external device-based gated delivery conditions. Methods: Six gating cycles were used to evaluate the gating performance of a standard production TrueBeam system that was not specially tuned in any way. The system was equipped with a factory installed external gating interface (EXGI). An in-house EXGI tester box was used to simulate the input gating signals. The gating cycles were selected based on long beam-on and short beam-off times, short beam-on and long beam-off times, or equal beam on and off times to check linac performance. The beam latencies were measured as the time difference between the logic high gating signal and the first or last target pulses with an oscilloscope. Tissue-Phantom Ratio, beam flatness, and dose distributions from 5 different plans were measured using the 6 different gating durations and the un-gated irradiation. A PTW 729 2-D array was used to compare 5 plans versus the un-gated delivery with a 1%/1mm gamma index passing criteria. Results: The beam latencies of the linac were based off of 20 samples for beam-on and beam-off, for each gating cycle. The average beam-on delays were measured to be between 57 and 66msec, with a maximum of 88 msec. The beam off latencies averaged between 19 and 26msec, with a maximum of 48 msec. TPR20,10 measurements showed beam energy stability within 0.5% of the un-gated delivery. Beam flatness was better than 2.5% for all gated cycles. All but two deliveries, the open field with 4 seconds on, 1 second off, and a five field IMRT plan with 0.5 seconds on, 2.5 seconds off, had >90% passing rate. Conclusion: TrueBeam demonstrates excellent beam stability with minimal beam latencies under external device-based gated operations. Dosimetric measurements show minimal variation in beam energy, flatness, and plan delivery. Authors are employees of Varian Medical Systems, Inc

  4. SU-E-T-403: Evaluation of the Beam Performance of a Varian TrueBeam Linear Accelerator Under External Device-Based Gated Delivery Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kobulnicky, K; Pawlak, D; Purwar, A [Varian Medical Systems, Inc., Palo Alto, CA (United States)

    2015-06-15

    Purpose: To examine the beam performance of a Varian TrueBeam linear accelerator under external device-based gated delivery conditions. Methods: Six gating cycles were used to evaluate the gating performance of a standard production TrueBeam system that was not specially tuned in any way. The system was equipped with a factory installed external gating interface (EXGI). An in-house EXGI tester box was used to simulate the input gating signals. The gating cycles were selected based on long beam-on and short beam-off times, short beam-on and long beam-off times, or equal beam on and off times to check linac performance. The beam latencies were measured as the time difference between the logic high gating signal and the first or last target pulses with an oscilloscope. Tissue-Phantom Ratio, beam flatness, and dose distributions from 5 different plans were measured using the 6 different gating durations and the un-gated irradiation. A PTW 729 2-D array was used to compare 5 plans versus the un-gated delivery with a 1%/1mm gamma index passing criteria. Results: The beam latencies of the linac were based off of 20 samples for beam-on and beam-off, for each gating cycle. The average beam-on delays were measured to be between 57 and 66msec, with a maximum of 88 msec. The beam off latencies averaged between 19 and 26msec, with a maximum of 48 msec. TPR20,10 measurements showed beam energy stability within 0.5% of the un-gated delivery. Beam flatness was better than 2.5% for all gated cycles. All but two deliveries, the open field with 4 seconds on, 1 second off, and a five field IMRT plan with 0.5 seconds on, 2.5 seconds off, had >90% passing rate. Conclusion: TrueBeam demonstrates excellent beam stability with minimal beam latencies under external device-based gated operations. Dosimetric measurements show minimal variation in beam energy, flatness, and plan delivery. Authors are employees of Varian Medical Systems, Inc.

  5. External Beam Radiotherapy for Prostate Cancer Patients on Anticoagulation Therapy: How Significant is the Bleeding Toxicity?

    International Nuclear Information System (INIS)

    Choe, Kevin S.; Jani, Ashesh B.; Liauw, Stanley L.

    2010-01-01

    Purpose: To characterize the bleeding toxicity associated with external beam radiotherapy for prostate cancer patients receiving anticoagulation (AC) therapy. Methods and Materials: The study cohort consisted of 568 patients with adenocarcinoma of the prostate who were treated with definitive external beam radiotherapy. Of these men, 79 were receiving AC therapy with either warfarin or clopidogrel. All patients were treated with three-dimensional conformal radiotherapy or intensity-modulated radiotherapy. Bleeding complications were recorded during treatment and subsequent follow-up visits. Results: With a median follow-up of 48 months, the 4-year actuarial risk of Grade 3 or worse bleeding toxicity was 15.5% for those receiving AC therapy compared with 3.6% among those not receiving AC (p < .0001). On multivariate analysis, AC therapy was the only significant factor associated with Grade 3 or worse bleeding (p < .0001). For patients taking AC therapy, the crude rate of bleeding was 39.2%. Multivariate analysis within the AC group demonstrated that a higher radiotherapy dose (p = .0408), intensity-modulated radiotherapy (p = 0.0136), and previous transurethral resection of the prostate (p = .0001) were associated with Grade 2 or worse bleeding toxicity. Androgen deprivation therapy was protective against bleeding, with borderline significance (p = 0.0599). Dose-volume histogram analysis revealed that Grade 3 or worse bleeding was minimized if the percentage of the rectum receiving ≥70 Gy was <10% or the rectum receiving ≥50 Gy was <50%. Conclusion: Patients taking AC therapy have a substantial risk of bleeding toxicity from external beam radiotherapy. In this setting, dose escalation or intensity-modulated radiotherapy should be used judiciously. With adherence to strict dose-volume histogram criteria and minimizing hotspots, the risk of severe bleeding might be reduced.

  6. External Beam Boost for Cancer of the Cervix Uteri When Intracavitary Therapy Cannot Be Performed

    International Nuclear Information System (INIS)

    Barraclough, Lisa Helen; Swindell, Ric; Livsey, Jacqueline E.; Hunter, Robin D.; Davidson, Susan E.

    2008-01-01

    Purpose: To assess the outcome of patients treated with radical radiotherapy for cervical cancer who received an external beam boost, in place of intracavitary brachytherapy (ICT), after irradiation to the whole pelvis. Methods and Materials: Case notes were reviewed for all patients treated in this way in a single center between 1996 and 2004. Patient and tumor details, the reasons why ICT was not possible, and treatment outcome were documented. Results: Forty-four patients were identified. The mean age was 56.4 years (range, 26-88 years). Clinical International Federation of Gynecology and Obstetrics or radiologic stage for Stages I, II, III, and IV, respectively, was 16%, 48%, 27%, and 7%. A total radiation dose of 54-70 Gy was given (75% received ≥60 Gy). Reasons for ICT not being performed were technical limitations in 73%, comorbidity or isolation limitations in 23%, and patient choice in 4%. The median follow-up was 2.3 years. Recurrent disease was seen in 48%, with a median time to recurrence of 2.3 years. Central recurrence was seen in 16 of the 21 patients with recurrent disease. The 5-year overall survival rate was 49.3%. The 3-year cancer-specific survival rate by stage was 100%, 70%, and 42% for Stages I, II, and III, respectively. Late Grades 1 and 2 bowel, bladder, and vaginal toxicity were seen in 41%. Late Grade 3 toxicity was seen in 2%. Conclusion: An external beam boost is a reasonable option after external beam radiotherapy to the pelvis when it is not possible to perform ICT

  7. Prostate biopsy after definitive treatment by interstitial iodine 125 implant or external beam radiation therapy

    International Nuclear Information System (INIS)

    Schellhammer, P.F.; el-Mahdi, A.M.; Higgins, E.M.; Schultheiss, T.E.; Ladaga, L.E.; Babb, T.J.

    1987-01-01

    The response to definitive radiation therapy of localized carcinoma of the prostate by iodine 125 implantation or external beam radiotherapy was monitored by examining specimens from biopsies performed after treatment. We analyzed 126 biopsy specimens obtained 18 months or more after treatment: 71 were obtained from 109 patients treated by iodine 125 and 55 from 197 patients treated by external beam radiotherapy. Thereafter, the disease status of these patients was examined at minimum 3-year intervals. No significant statistical difference was found between the negative specimen rates of the 2 treatment modalities: 46 of 71 (65 per cent) after iodine 125 implantation and 39 of 55 (71 per cent) after external beam radiotherapy were negative. To analyze the predictive value of biopsy results 103 patients whose prostatic examination results were normal at biopsy or who showed regression of tumor size and tumor induration after radiation were evaluated. The biopsy results from all patients were combined for analysis. Of 77 patients with negative biopsy specimens 16 (21 per cent) have had recurrent disease, compared to 17 of 26 (65 per cent) with positive biopsy specimens (p equals 0.00005). Of the 77 patients with negative biopsy specimens 7 (9 per cent) had local disease recurrence, compared to 12 of 26 (46 per cent) with a positive biopsy specimen (p equals 0.0001). The value of a positive specimen to predict failure remained significant with patients stratified by pre-treatment clinical stage and grade of the disease. Our results show that patients with positive specimens from the prostate who had been judged clinically by rectal examination to have responded to radiation therapy had a significantly increased incidence of local and distant failure compared to patients who had negative biopsy specimens

  8. Cervix Regression and Motion During the Course of External Beam Chemoradiation for Cervical Cancer

    International Nuclear Information System (INIS)

    Beadle, Beth M.; Jhingran, Anuja; Salehpour, Mohammad; Sam, Marianne; Iyer, Revathy B.; Eifel, Patricia J.

    2009-01-01

    Purpose: To evaluate the magnitude of cervix regression and motion during external beam chemoradiation for cervical cancer. Methods and Materials: Sixteen patients with cervical cancer underwent computed tomography scanning before, weekly during, and after conventional chemoradiation. Cervix volumes were calculated to determine the extent of cervix regression. Changes in the center of mass and perimeter of the cervix between scans were used to determine the magnitude of cervix motion. Maximum cervix position changes were calculated for each patient, and mean maximum changes were calculated for the group. Results: Mean cervical volumes before and after 45 Gy of external beam irradiation were 97.0 and 31.9 cc, respectively; mean volume reduction was 62.3%. Mean maximum changes in the center of mass of the cervix were 2.1, 1.6, and 0.82 cm in the superior-inferior, anterior-posterior, and right-left lateral dimensions, respectively. Mean maximum changes in the perimeter of the cervix were 2.3 and 1.3 cm in the superior and inferior, 1.7 and 1.8 cm in the anterior and posterior, and 0.76 and 0.94 cm in the right and left lateral directions, respectively. Conclusions: Cervix regression and internal organ motion contribute to marked interfraction variations in the intrapelvic position of the cervical target in patients receiving chemoradiation for cervical cancer. Failure to take these variations into account during the application of highly conformal external beam radiation techniques poses a theoretical risk of underdosing the target or overdosing adjacent critical structures

  9. Radiation dose to laterally transposed ovaries during external beam radiotherapy for cervical cancer

    International Nuclear Information System (INIS)

    Mazonakis, Michael; Damilakis, John; Varveris, Haris; Gourtsoyiannis, Nicholas

    2006-01-01

    The purpose of this study was to estimate the radiation dose to laterally transposed ovaries from external beam radiotherapy for cervical cancer. Dose measurements were performed in a modified humanoid phantom using a 6 MV photon beam. The dependence of the ovarian dose upon the field size, the distance from the primary irradiation field and the presence of wedges or gonadal shielding was determined. For a tumor dose of 45 Gy, ovarian dose was 0.88-8.51 Gy depending on the field size employed and the location of the transposed ovary in respect to the treatment field. Positioning of 7 cm thick shielding reduced the dose to ovary by less than 19%. The use of wedges increased the ovarian dose by a factor up to 1.5. Accurate radiographic localization of the ovaries allows the use of the presented dosimetric results to obtain a reasonable prediction of the ovarian dose

  10. An Apparatus For Student Projects Using External-Beam PIXE And PIGE

    International Nuclear Information System (INIS)

    Correll, Francis D.; Edsall, Douglas W.; DePooter, Katherine A.; Maskell, Nicholas D.; Vanhoy, Jeffrey R.

    2011-01-01

    We recently installed a simple endstation at the Naval Academy Tandem Accelerator Laboratory to support student projects using external-beam PIXE and PIGE. It consists of a short, graphite-lined beamline extension with a thin window, an interlocked box that surrounds the target, detectors for x- and gamma rays, provision for flooding the target with helium gas, easily changed x-ray absorbers, and a compact video camera for monitoring the position of the beam spot. We used this system to measure the elemental composition of colonial-era architectural materials, principally bricks and mortar, from James Madison's Montpelier, the reconstructed Virginia estate of the fourth President of the United States. We describe the design and construction of the system, relate some of our experiences using it, and present some preliminary data from our investigations.

  11. Measurement and properties of the dose-area product ratio in external small-beam radiotherapy.

    Science.gov (United States)

    Niemelä, Jarkko; Partanen, Mari; Ojala, Jarkko; Sipilä, Petri; Björkqvist, Mikko; Kapanen, Mika; Keyriläinen, Jani

    2017-06-21

    In small-beam radiation therapy (RT) the measurement of the beam quality parameter, i.e. the tissue-phantom ratio or TPR 20,10 , using a conventional point detector is a challenge. To obtain reliable results, one has to consider potential sources of error, including volume averaging and adjustment of the point detector into the narrow beam. To overcome these challenges, a different type of beam quality parameter in small beams was studied, namely the dose-area product ratio, or DAPR 20,10 . With this method, the measurement of a dose-area product (DAP) using a large-area plane-parallel chamber (LAC) eliminates the uncertainties in detector positioning and volume averaging that are present when using a point detector. In this study, the properties of the DAPR 20,10 of a cone-collimated 6 MV photon beam were investigated using Monte Carlo (MC) calculations and the obtained values were compared to measurements obtained using two LAC detectors, PTW Type 34073 and PTW Type 34070. In addition, the possibility of determining the DAP using EBT3 film and a Razor diode detector was studied. The determination of the DAPR 20,10 value was found to be feasible in external small-beam radiotherapy using cone-collimated beams with diameters from 4-40 mm, based on the results of the two LACs, the MC calculations and the Razor diode. The measurements indicated a constant DAPR 20,10 value for fields 20-40 mm in diameter, with a maximum relative change of 0.6%, but an increase of 7.0% for fields from 20-4 mm in diameter for the PTW Type 34070 chamber. Simulations and measurements showed an increase of DAPR 20,10 with increasing LAC size or dose integral area for the studied 4-40 mm cone-collimated 6 MV photon beams. This has the consequence that there should be a reference to the size of the used LAC active area or the DAP integration area with the reported DAPR 20,10 value.

  12. Measurement and properties of the dose-area product ratio in external small-beam radiotherapy

    Science.gov (United States)

    Niemelä, Jarkko; Partanen, Mari; Ojala, Jarkko; Sipilä, Petri; Björkqvist, Mikko; Kapanen, Mika; Keyriläinen, Jani

    2017-06-01

    In small-beam radiation therapy (RT) the measurement of the beam quality parameter, i.e. the tissue-phantom ratio or TPR20,10, using a conventional point detector is a challenge. To obtain reliable results, one has to consider potential sources of error, including volume averaging and adjustment of the point detector into the narrow beam. To overcome these challenges, a different type of beam quality parameter in small beams was studied, namely the dose-area product ratio, or DAPR20,10. With this method, the measurement of a dose-area product (DAP) using a large-area plane-parallel chamber (LAC) eliminates the uncertainties in detector positioning and volume averaging that are present when using a point detector. In this study, the properties of the DAPR20,10 of a cone-collimated 6 MV photon beam were investigated using Monte Carlo (MC) calculations and the obtained values were compared to measurements obtained using two LAC detectors, PTW Type 34073 and PTW Type 34070. In addition, the possibility of determining the DAP using EBT3 film and a Razor diode detector was studied. The determination of the DAPR20,10 value was found to be feasible in external small-beam radiotherapy using cone-collimated beams with diameters from 4-40 mm, based on the results of the two LACs, the MC calculations and the Razor diode. The measurements indicated a constant DAPR20,10 value for fields 20-40 mm in diameter, with a maximum relative change of 0.6%, but an increase of 7.0% for fields from 20-4 mm in diameter for the PTW Type 34070 chamber. Simulations and measurements showed an increase of DAPR20,10 with increasing LAC size or dose integral area for the studied 4-40 mm cone-collimated 6 MV photon beams. This has the consequence that there should be a reference to the size of the used LAC active area or the DAP integration area with the reported DAPR20,10 value.

  13. In-vivo (entrance) dose measurements in external beam radiotherapy with aqueous FBX dosimetry system

    International Nuclear Information System (INIS)

    Semwal, M.K.; Thakur, P.K.; Bansal, A.K.; Vidyasagar, P.B.

    2005-01-01

    FBX aqueous chemical dosimetry system has been found useful in radiotherapy owing to its low dose measuring capability. In the present work, entrance dose measurements in external beam radiotherapy on a telecobalt machine were carried out with the system on 100 patients. Treatments involving simple beam arrangement of open parallel-opposed beams in cranial and pelvic irradiations were selected for this study. In place of a spectrophotometer, a simple and inexpensive colorimeter was used for absorbance measurements. The purpose was to assess the efficacy of the FBX system for in-vivo dose measurements. The results obtained show that the average discrepancy between the measured and expected dose for both categories of patients was 0.2% (standard deviation 3.2%) with a maximum of +1 0.3%. There were 5.5% cases showing more than ± 5% discrepancy. Comparison of the results obtained with published work on entrance dose measurements, with diode detectors, shows that the inexpensive FBX system can be used for in-vivo (entrance) dose measurements for simple beam arrangements in radiotherapy and can thus serve as a useful QA tool. (author)

  14. Interfacial stresses in damaged RC beams strengthened with externally bonded CFRP plate

    International Nuclear Information System (INIS)

    Benrahou, K.H.; Adda bedia, E.A.; Benyoucef, S.; Tounsi, A.; Benguediab, M.

    2006-01-01

    A theoretical method to predict the interfacial stresses in the adhesive layer of damaged reinforced concrete beams strengthened with externally bonded carbon fiber-reinforced polymer (CFRP) plate is presented. The adopted model is developed including the adherend shear deformations by assuming a linear shear stress through the depth of the RC beam [A. Tounsi, Int. J. Solids Struct., in press], while all existing solutions neglect this effect [e.g. S. Benyoucef, A. Tounsi, S.A. Meftah, E.A. Adda Bedia, Compos. Interfaces, in press; S.T. Smith, J.G. Teng, Eng. Struct. 23 (7) (2001) 857-871; T.M. Roberts, Struct. Eng. 67 (12) (1989) 229-233; A. Tounsi, S. Benyoucef, Int. J. Adhes. Adhes., in press; T. Stratford, J. Cadei, Construct. Building Mater. 20 (2006) 34-35]. In addition, in the present study the anisotropic damage model is adopted to describe the damage of the RC beams. It is shown that the damage has a significant effect on the interfacial stresses in FRP-damaged RC beam

  15. High dose rate interstitial brachytherapy with external beam irradiation for localized prostate cancer. Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Hiratsuka, Junichi; Jo, Yoshimasa; Yoden, Eisaku; Tanaka, Hiroyoshi; Imajo, Yoshinari [Kawasaki Medical School, Kurashiki, Okayama (Japan); Nagase, Naomi; Narihiro, Naomasa; Kubota, Juichi

    2000-12-01

    This study was undertaken to assess the biochemical and pathological results of combined external beam radiotherapy and high dose rate Ir-192 brachytherapy (HDR-Ir192) for clinically localized prostate cancer. Between October 1997 and August 1999, 39 evaluable patients with adenocarcinoma of prostate diagnosed by biopsy were treated with interstitial and external beam irradiation. Patients ranged in age from 58-82 years, with a mean of 69.7 years. T1c, T2 and T3 tumors, according to the UICC classification system (1997), were found in 7, 21 and 11 cases respectively. The mean initial pre-treatment PSA was 35.9 ng/ml (median 13.2), with 77% of the patients having had a pre-treatment PSA greater than 10 ng/ml. Of all patients, 17 had received pre-treatment hormonal therapy. Hormonal pretreatment was stopped at the beginning of radiotherapy in all cases. External beam four-field box irradiation was given to the small pelvis to a dose of 45 Gy/25 fractions. Three HDR-Ir192 treatments were given over a 30-h period, with 5.5 Gy per fraction at the circumference of the prostate gland over the course of this study. Biochemical failure was defined as a PSA level >1.5 ng/ml and rising on three consecutive values. If serial post-treatment PSA levels showed a continuous downward trend, failure was not scored. The patient with clinical evidence of progression was classified as a clinical failure. The median follow-up at the time of evaluation was 19.6 months. A post-treatment PSA level {<=}1.0 ng/ml was seen in 26 (67%) patients, and values from >1.0 to {<=}2.0 ng/ml were seen in 10 (26%) patients. Biochemical failure was not seen in 38 patients except for one patient who developed a distant bone metastasis with negative prostatic biopsy 15 months after treatment. Biochemical control rate was 100% (38/38) except for the patient with bone metastasis classified as clinical failure. Negative biopsies 18 months after treatment were found in 93% (14/15) of patients. Only one patient

  16. Elemental analysis of ancient Chinese bronze artifacts with external-beam PIXE

    International Nuclear Information System (INIS)

    Lin, E.K.; Yu, Y.C.; Wang, C.W.; Shen, C.T.; Huang, Y.M.; Wu, S.C.; Hsieh, C.H.

    1992-01-01

    External-beam PIXE has been applied for the determination of the elemental composition of ancient Chinese bronze artifacts. Characteristic x-ray spectra from the samples bombarded with protons of 3 MeV have been measured with a HPGe detector. At each sample three spots were irradiated per run. Results of measurements on three fragments of bronze drinking vessels and helmet of Chinese ancient Chou and Shang dynasties (17th-8th century B.C.) are presented. To check the analytical method, we have also made measurements on the elemental composition of some modern coins. The results are discussed. (author)

  17. Analyses of inks and papers in historical documents through external beam PIXE techniques

    International Nuclear Information System (INIS)

    Cahill, T.A.; Kusko, B.; California Univ., Davis; Schwab, R.N.

    1981-01-01

    PIXE analyses of documents can be carried out to high senstitivty in an external beam configuration designed to protect historical materials from damage. Test runs have shown that a properbly designed system with high solid angle can operate at less than 1% of the flux necessary to cause any discoloration whatsoever on papers of the 17th and 18th centuries. The composition of these papers is suprisingly complex, yet retains distinct association with the historical period, paper source, and even the individual sheets of paper that are folded and cut to make groups of pages. Early studies are planned on historical forgeries. (orig.)

  18. Elemental analysis of ancient Chinese bronze artifacts with external-beam PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Lin, E.K.; Yu, Y.C.; Wang, C.W.; Shen, C.T.; Huang, Y.M.; Wu, S.C.; Hsieh, C.H. [Academia Sinica, Taipei, TW (China). Inst. of Physics

    1992-12-31

    External-beam PIXE has been applied for the determination of the elemental composition of ancient Chinese bronze artifacts. Characteristic x-ray spectra from the samples bombarded with protons of 3 MeV have been measured with a HPGe detector. At each sample three spots were irradiated per run. Results of measurements on three fragments of bronze drinking vessels and helmet of Chinese ancient Chou and Shang dynasties (17th-8th century B.C.) are presented. To check the analytical method, we have also made measurements on the elemental composition of some modern coins. The results are discussed. (author).

  19. Trace elements in human, cattle and swine teeth, measured by external beam PIXE-PIGE setup

    International Nuclear Information System (INIS)

    Tabacniks, M.H.; Rizzutto, M.A.; Added, N.; Liguori Neto, R.; Acquadro, J.C.; Vilela, M.; Oliveira, T.R.C.F.; Markarian, R.A.; Mori, M.

    2001-01-01

    The use of animal teeth to replace human teeth in dentistry school classes and to test chemicals and fillings, motivated for a better characterization of the elementary composition of their enamel, since some of the chemical properties, adhesion and chemical compatibility may depend on these parameters. Cattle, swine and human teeth were collected by dentists of the University of Sao Paulo. These teeth came primarily from Sao Paulo region and were analyzed for trace elements at the Open Nuclear Physics Laboratory, using a high energy external proton beam, PIXE-PIGE setup

  20. Controlling laser ablation plasma with external electrodes. Application to sheath dynamics study and beam physics

    International Nuclear Information System (INIS)

    Isono, Fumika; Nakajima, Mitsuo; Hasegawa, Jun; Kawamura, Tohru; Horioka, Kazuhiko

    2013-01-01

    The potential of laser ablation plasma was controlled successfully by using external ring electrodes. We found that an electron sheath is formed at the plasma boundary, which plays an important role in the potential formation. When the positively biased plasma reaches a grounded grid, electrons in the plasma are turned away and ions are accelerated, which leads to the formation of a virtual anode between the grid and an ion probe. We think that this device which can raise the plasma potential up to order of kV can be applied to the study of sheath dynamics and to a new type of ion beam extraction. (author)

  1. Phase-space database for external beam radiotherapy. Summary report of a consultants' meeting

    International Nuclear Information System (INIS)

    Capote, R.; Jeraj, R.; Ma, C.M.; Rogers, D.W.O.; Sanchez-Doblado, F.; Sempau, J.; Seuntjens, J.; Siebers, J.V.

    2006-01-01

    A summary is given of a Consultants' Meeting assembled to discuss and recommend actions and activities to prepare a Phase-space Database for External Beam Radiotherapy. The new database should serve to disseminate phase-space data of those accelerators and 60 Co units used in radiotherapy through the compilation of existing data that have been properly validated. Both the technical discussions and the resulting work plan are described, along with the detailed recommendations for implementation. The meeting was jointly organized by NAPC-Nuclear Data Section and NAHU-Dosimetry and Medical Radiation Physics Section. (author)

  2. Pelvic control following external beam radiation for surgical Stage I endometrial adenocarcinoma

    International Nuclear Information System (INIS)

    Rush, Stephen; Gal, David; Potters, Louis; Bosworth, Jay; Lovecchio, John

    1995-01-01

    Purpose: To determine if postoperative external pelvic radiation (EBRT), without vaginal brachytherapy, is sufficient to prevent vaginal cuff and pelvic recurrences in patients with surgical Stage I endometrial adenocarcinoma (ACA). Methods and Materials: The records of 122 patients with surgical Stage I endometrial cancer were reviewed. There were 87 patients with ACA who received EBRT alone and are the subject of this study. Their radiation records were reviewed. All patients underwent exploration, total abdominal hysterectomy, and bilateral salpingo-oophorectomy (TAH BSO), and pelvic and paraaortic lymph node sampling. They were staged according to the FIGO 1988 surgical staging system recommendations. Postoperatively, pelvic EBRT was administered by megavoltage equipment using four fields, to a total dose of 45 to 50.4 Gy. Actuarial survival and disease free survival were calculated according to Kaplan-Meier Method. Results: Twenty-seven patients with Stage IA Grade 1 or 2 ACA with less than one-third myometrial invasion, who did not receive EBRT, and eight patients with histology other than adenocarcinoma (i.e., serous papillary, mucinous, etc.) were not included in the study. For the remaining 87 patients who are in the study group, the median follow-up was 52 months (range: 12-82 months). The 5-year overall survival for these 87 patients was 92%, with a disease-free survival of 83%. There were no tumor recurrences in the upper vagina or in the pelvis. Two patients developed small bowel obstruction (no surgery required), and one patient developed chronic enteritis. Conclusion: Adjuvant external pelvic radiation, without vaginal brachytherapy, prevents pelvic and vaginal cuff recurrences in surgical Stage I endometrial ACA

  3. Characterization of the dose perturbation in tissue by stents as a function of external beam energy

    International Nuclear Information System (INIS)

    Schell, M.C.; Rosenzweig, D.P.; Weaver, K.A.; Rubin, P.

    1997-01-01

    Purpose: External beam irradiation of coronary arteries was shown to be detrimental in an animal model for the prevention of neointimal hyperplasia in the presence of stents when orthovoltage x-ray beams are used. This present study investigated the effect of beam energy on the dose distribution in the wall of the artery as a function of energy in the presence of stents in order to ascertain the effect on the dose due to beam energy. Materials and Methods: 250 kVp x-rays and 6-MV x rays were used to irradiate a stent placed in an homogeneous phantom. Radiochromic film densitometry and Monte Carlo calculations were used to measure and to simulate the dose distribution in the proximity of the stent. Result: External beam irradiation was reported to not only fail to prevent neointimal hyperplasia, but actually accentuate the neointimal response to a prompt mechanical injury in the artery. The photoelectric effect, which dominates low-energy x-ray interactions, produces recoil electrons in the stent which enhance the dose surrounding intima. The photoelectrons generated in nickel and iron have an extremely short range in normal tissue, approximately 0.1 mm. Initial estimates of orthovoltage x-ray interactions with the stent indicate a dose enhancement in the orthovoltage range by a factor of 2 to 3 due to the rise in the photoelectric cross section in this energy range depending on the elemental composition of the stent. Film densitometry verifies this dose enhancement. The Monte Carlo calculations yield a dose enhancement and the dose fall off with distance from the stent when irradiated with orthovoltage x-rays. Conversely when the tissue and stent are irradiated with megavoltage x-rays, the dose enhancement in this region is a factor of 1.15 in close proximity to the stent and 1.0 at distances greater than 0.1 mm. 6-MV photon interactions in tissue and iron are predominantly through Compton scattering. The Compton effect is dependent on the electron density in the

  4. Distortion of optical feedback signals in microchip Nd:YAG lasers subjected to external multi-beam interference feedback

    International Nuclear Information System (INIS)

    Yi-Dong, Tan; Shu-Lian, Zhang; Zhou, Ren; Cheng, Ren; Yi-Nan, Zhang

    2010-01-01

    This paper proposes a theoretical analysis for the characteristics of an external cavity Nd:YAG laser with feedback of multiple-beam interference, which is induced by the multi-reentrance of the light from the external Fabry–Perot cavity. The theoretical model considers the multiple beam interference of the external Fabry–Perot cavity. It is found that the optical feedback signals are distorted to pulse waveforms instead of the sinusoidal ones in conventional feedback. The experimental results are in good agreement with the theoretical analysis. The obtained theoretical and experimental results can advance the development of a laser feedback interferometer

  5. External proton and Li beams; Haces externos de protones y litios

    Energy Technology Data Exchange (ETDEWEB)

    Schuff, Juan A; Burlon, Alejandro A; Debray, Mario E; Kesque, Jose M; Kreiner, Andres J; Stoliar, Pablo A; Naab, Fabian; Ozafran, Mabel J; Vazquez, Monica E [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Fisica; Policastro, Lucia L; Duran, Hebe; Molinari, Beatriz L; O' Connor, Silvia E; Saint-Martin, Maria L.G.; Palmieri, Monica; Bernaola, Omar A; Opezzo, Oscar J [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Radiobiologia; Mazal, A; Favaudon, F; Henry, Y [Institut Curie, 75 - Paris (France); Perez de la Hoz, A.; Somacal, Hector; Valda, Alejandro; Canevas, S; Ruffolo, M; Tasat, D R [Universidad Nacional de General San Martin, Villa Ballester (Argentina). Escuela de Ciencia y Tecnologia; Davidson, Miguel; Davidson, Jorge [Buenos Aires Univ. (Argentina). Dept. de Fisica; Delacroix, S; Nauraye, C; Brune, E; Gautier, C; Habrand, J L [Centre de Protontherapie, 91 - Orsay (France); Muhlmann, M C [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina)

    2000-07-01

    In the frame of a feasibility study to introduce proton therapy in Argentina in a collaborative agreement between the Physics and Radiobiology Departments of the National Atomic Energy Commission or Argentina and the Centre de Protontherapie de Orsay, France, external proton and Li beams were produced at the TANDAR accelerator in Buenos Aires. The specific aim of this work was to start radiobiology studies on cell cultures and small laboratory animals. In particular we seek to determine here the relative biological effectiveness, RBE, for proton and Li beams as a function of energy for different tumor and normal cell lines. The 24 MeV proton beam was diffused using a 25 {mu}m gold foil and extracted through a Kapton window to obtain a homogeneous field (constant to 95%) of about 7 cm in diameter. Measurements were carried out with quasi-monoenergetic beams (of 20.2 {+-} 0.07 MeV, 2.9 {+-} 0.10 MeV y 1.5 {+-} 0.1 MeV for protons and 21.4 {+-} 0.4 MeV for Lithium). Proton fluence and Bragg peaks were measured. The dose delivered in each case was monitored on-line with a calibrated transmission ionization chamber. Three cell lines PDV, PDVC 57 and V 79 (as a reference) were irradiated with {gamma}-rays, proton and lithium beams with linear energy transfer (LET) from 2 to 100 keV/{mu}m. RBE values in the range of 1.2-5.9 were obtained. In addition preliminary studies on chromosomal aberrations and viability of alveolar macrophages were carried out. (author)

  6. Radiobiological comparison of external beam irradiation and radioimmunotherapy in renal cell carcinoma xenografts

    International Nuclear Information System (INIS)

    Wessels, B.W.; Vessella, R.L.; Palme, D.F. II; Berkopec, J.M.; Smith, G.K.; Bradley, E.W.

    1989-01-01

    Growth delay was measured in TK-82 renal cell carcinoma (RCC) xenografts implanted in nude mice receiving single fraction external beam irradiation (SF-XRT), multifraction external beam irradiation (MF-XRT), or radioimmunotherapy (RIT). Thermoluminescent dosimeter(s) (TLD) and autoradiography were used to ascertain the average absorbed dose delivered and the degree of heterogeneous uptake of radiolabeled antibody for the RIT irradiations. For intravenous administered activities of 100, 200, 400, and 600 microCi of I-131 labeled A6H antibody, volume doubling times (VDT) and TLD absorbed dose measurements for each administered activity were 7 days (341 cGy), 38 days (383 cGy), 85 days (886 cGy) and no regrowth (1034 cGy), respectively. For SF-XRT irradiations of 500, 1000, and 1500 cGy, VDT times were 11, 62, and 103 days, respectively. MF-XRT of 4 X 250 cGy over a 2-week period yielded a VDT of 25 days. Marked peripheral activity deposition was noted on most autoradiographs from multiple tumor samples. These data suggest that an equivalent to superior tumor growth delay is obtained for absorbed doses delivered by exponentially decaying low dose rate radioimmunotherapy RIT compared to similar doses of acute dose rate XRT as quantitated by the TLD method

  7. External cervical resorption: an analysis using cone beam and microfocus computed tomography and scanning electron microscopy.

    Science.gov (United States)

    Gunst, V; Mavridou, A; Huybrechts, B; Van Gorp, G; Bergmans, L; Lambrechts, P

    2013-09-01

    To provide a three-dimensional representation of external cervical resorption (ECR) with microscopy, stereo microscopy, cone beam computed tomography (CT), microfocus CT and scanning electron microscopy (SEM). External cervical resorption is an aggressive form of root resorption, leading to a loss of dental hard tissues. This is due to clastic action, activated by a damage of the covering cementum and stimulated probably by infection. Clinically, it is a challenging situation as it is characterized by a late symptomatology. This is due to the pericanalar protection from a resorption-resistant sheet, composed of pre-dentine and surrounding dentine. The clastic activity is often associated with an attempt to repair, seen by the formation of osteoid tissue. Cone beam CT is extremely useful in the diagnoses and treatment planning of ECR. SEM analyses provide a better insight into the activity of osteoclasts. The root canal is surrounded by a layer of dentine that is resistant to resorption. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  8. Tumor bed delineation for external beam accelerated partial breast irradiation: A systematic review

    International Nuclear Information System (INIS)

    Yang, T. Jonathan; Tao, Randa; Elkhuizen, Paula H.M.; Vliet-Vroegindeweij, Corine van; Li, Guang; Powell, Simon N.

    2013-01-01

    In recent years, accelerated partial breast irradiation (APBI) has been considered an alternative to whole breast irradiation for patients undergoing breast-conserving therapy. APBI delivers higher doses of radiation in fewer fractions to the post-lumpectomy tumor bed with a 1–2 cm margin, targeting the area at the highest risk of local recurrence while sparing normal breast tissue. However, there are inherent challenges in defining accurate target volumes for APBI. Studies have shown that significant interobserver variation exists among radiation oncologists defining the lumpectomy cavity, which raises the question of how to improve the accuracy and consistency in the delineation of tumor bed volumes. The combination of standardized guidelines and surgical clips significantly improves an observer’s ability in delineation, and it is the standard in multiple ongoing external-beam APBI trials. However, questions about the accuracy of the clips to mark the lumpectomy cavity remain, as clips only define a few points at the margin of the cavity. This paper reviews the techniques that have been developed so far to improve target delineation in APBI delivered by conformal external beam radiation therapy, including the use of standardized guidelines, surgical clips or fiducial markers, pre-operative computed tomography imaging, and additional imaging modalities, including magnetic resonance imaging, ultrasound imaging, and positron emission tomography/computed tomography. Alternatives to post-operative APBI, future directions, and clinical recommendations were also discussed

  9. 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

  10. Development of a multi-detector and a systematic imaging system on the AGLAE external beam

    International Nuclear Information System (INIS)

    Pichon, L.; Moignard, B.; Lemasson, Q.; Pacheco, C.; Walter, P.

    2014-01-01

    The New AGLAE external beamline provides analytical data for the understanding of the structure of archaeological and artistic objects, their composition, properties, and changes over time. One of the objectives of this project is to design and set up a new non-invasive acquisition system increasing the quality of the X-ray spectra and reducing the beam current on sensitive materials from work of art. To that end, the surface and the number of PIXE detectors have been increased to implement a cluster of SDD detectors. This can also provide the possibility to accomplish large and/or fast maps on artifacts with a scanning of the beam on the sample. During the mapping, a multi-parameter system saves each event from X-ray, gamma and particle detectors, simultaneously with the X and Y positions of the beam on the sample. To process the data, different softwares have been developed or updated. A first example on a decorated medieval shard highlights the perspectives of the technique

  11. A new mapping acquisition and processing system for simultaneous PIXE-RBS analysis with external beam

    International Nuclear Information System (INIS)

    Pichon, L.; Beck, L.; Walter, Ph.; Moignard, B.; Guillou, T.

    2010-01-01

    The combination of ion beam analysis techniques is particularly fruitful for the study of cultural heritage objects. For several years, the AGLAE facility of the Louvre laboratory has been implementing these techniques with an external beam. The recent set-up permits to carry out PIXE, PIGE and RBS simultaneously on the same analyzed spot with a particle beam of approximately 20 μm diameter. A new mapping system has been developed in order to provide elemental concentration maps from the PIXE and RBS spectra. This system combines the Genie2000 spectroscopy software with a homemade software that creates maps by handling acquisition with the object position. Each pixel of each PIXE and RBS maps contains the spectrum normalised by the dose. After analysing each pixel of the PIXE maps (low and high energy X-ray spectra) with the Gupixwin peak-fitting software, quantitative elemental concentrations are obtained for the major and trace elements. This paper presents the quantitative elemental maps extracted from the PIXE spectra and the development of RBS data processing for light element distribution and thin layer characterization. Examples on rock painting and lustrous ceramics will be presented.

  12. Mechanical Behavior of Steel Fiber-Reinforced Concrete Beams Bonded with External Carbon Fiber Sheets.

    Science.gov (United States)

    Gribniak, Viktor; Tamulenas, Vytautas; Ng, Pui-Lam; Arnautov, Aleksandr K; Gudonis, Eugenijus; Misiunaite, Ieva

    2017-06-17

    This study investigates the mechanical behavior of steel fiber-reinforced concrete (SFRC) beams internally reinforced with steel bars and externally bonded with carbon fiber-reinforced polymer (CFRP) sheets fixed by adhesive and hybrid jointing techniques. In particular, attention is paid to the load resistance and failure modes of composite beams. The steel fibers were used to avoiding the rip-off failure of the concrete cover. The CFRP sheets were fixed to the concrete surface by epoxy adhesive as well as combined with various configurations of small-diameter steel pins for mechanical fastening to form a hybrid connection. Such hybrid jointing techniques were found to be particularly advantageous in avoiding brittle debonding failure, by promoting progressive failure within the hybrid joints. The use of CFRP sheets was also effective in suppressing the localization of the discrete cracks. The development of the crack pattern was monitored using the digital image correlation method. As revealed from the image analyses, with an appropriate layout of the steel pins, brittle failure of the concrete-carbon fiber interface could be effectively prevented. Inverse analysis of the moment-curvature diagrams was conducted, and it was found that a simplified tension-stiffening model with a constant residual stress level at 90% of the strength of the SFRC is adequate for numerically simulating the deformation behavior of beams up to the debonding of the CFRP sheets.

  13. Development of a multi-detector and a systematic imaging system on the AGLAE external beam

    Energy Technology Data Exchange (ETDEWEB)

    Pichon, L., E-mail: laurent.pichon@culture.gouv.fr [Centre de recherche et de restauration des musées de France, C2RMF, Palais du Louvre – Porte des Lions, 14 Quai François Mitterrand, 75001 Paris (France); Fédération de recherche NewAGLAE, FR3506 CNRS/Ministère de la Culture/UPMC, Palais du Louvre, 75001 Paris (France); Moignard, B.; Lemasson, Q.; Pacheco, C. [Centre de recherche et de restauration des musées de France, C2RMF, Palais du Louvre – Porte des Lions, 14 Quai François Mitterrand, 75001 Paris (France); Fédération de recherche NewAGLAE, FR3506 CNRS/Ministère de la Culture/UPMC, Palais du Louvre, 75001 Paris (France); Walter, P. [Fédération de recherche NewAGLAE, FR3506 CNRS/Ministère de la Culture/UPMC, Palais du Louvre, 75001 Paris (France); UPMC Univ Paris 06, CNRS-UMR 8220, Laboratoire d’archéologie moléculaire et structurale, LAMS, F-75005 Paris (France)

    2014-01-01

    The New AGLAE external beamline provides analytical data for the understanding of the structure of archaeological and artistic objects, their composition, properties, and changes over time. One of the objectives of this project is to design and set up a new non-invasive acquisition system increasing the quality of the X-ray spectra and reducing the beam current on sensitive materials from work of art. To that end, the surface and the number of PIXE detectors have been increased to implement a cluster of SDD detectors. This can also provide the possibility to accomplish large and/or fast maps on artifacts with a scanning of the beam on the sample. During the mapping, a multi-parameter system saves each event from X-ray, gamma and particle detectors, simultaneously with the X and Y positions of the beam on the sample. To process the data, different softwares have been developed or updated. A first example on a decorated medieval shard highlights the perspectives of the technique.

  14. External beam radiotherapy dose response characteristics of 1127 men with prostate cancer treated in the PSA era

    International Nuclear Information System (INIS)

    Pollack, Alan; Smith, Lewis G.; Eschenbach, Andrew C. von

    2000-01-01

    Purpose: To characterize the relationship of radiotherapy dose to prostate cancer patient outcome, with an emphasis on the influence of pretreatment prognostic variables. Methods and Materials: The 1127 Stage T1-T4 prostate cancer patients examined were treated consecutively with definitive external beam radiotherapy at the University of Texas-M.D. Anderson Cancer Center from 1987 to 1997. All had a pretreatment prostate-specific antigen (PSA) level. Treatment failure was defined as two consecutive PSA elevations on follow-up. There were 994 patients treated with a four-field box throughout to 60-70 Gy after a small reduction at 46 Gy and 161 treated with a six-field conformal boost after 46 Gy to 74-78 Gy. No patient received neoadjuvant or adjuvant androgen ablation. Median follow-up was 51.8 months. Results: Patients were divided into three radiotherapy dose groups consisting of ≤67 Gy (n = 500), >67-77 Gy (n = 495), and >77 Gy (n = 132). Relative to other prognostic factors, there were fewer patients treated to the highest dose level with a pretreatment PSA (PSAB) ≤4 or >20 ng/ml, Stage T3/T4 disease, or a Gleason score of 2-6. Actuarial 4-year freedom from biochemical failure (bNED) rates for the entire cohort were 54%, 71%, and 77% (p 67-77 Gy was associated with improved bNED rates for all PSAB (≤10 and >10), stage (T1/T2 and T3/T4), and Gleason score (2-6 and 7-10) subgroups tested. In contrast, the only prognostic group that benefited from raising dose from >67-77 Gy to >77 Gy was patients with a PSAB >10 ng/ml; although trends were noted for Stage T1/T2 and Gleason 2-6 patients. Patients with the combined features of a PSAB >10 ng/ml and Stage T1/T2 disease had 4-year bNED rates of 61% and 93% at the intermediate- and high-dose levels. A strongly significant linear association between dose (60-78 Gy) and 4-year actuarial bNED was demonstrated for patients with these intermediate-risk features. Conclusion: Prostate cancer dose response to external

  15. Phase II Radiation therapy oncology group trial of weekly paclitaxel and conventional external beam radiation therapy for supratentorial glioblastoma multiforme

    International Nuclear Information System (INIS)

    Langer, Corey J.; Ruffer, James; Rhodes, Harker; Paulus, Rebecca; Murray, Kevin; Movsas, Benjamin; Curran, Walter

    2001-01-01

    Purpose: Fractionated external beam radiotherapy (EBRT) ± carmustine (BCNU) is the standard of care for patients with glioblastoma multiforme (GBM), but survival results remain poor. Preclinical studies indicate synergy between RT and paclitaxel (TAX) in astrocytoma cell lines. Phase I studies in GBM have demonstrated a maximum tolerated dose for TAX of 225 mg/m 2 /3 h/week x 6, during EBRT, with no exacerbation of typical RT-induced toxicities. The Radiation Therapy Oncology Group (RTOG) therefore mounted a Phase II study to determine the feasibility and efficacy of conventional EBRT and concurrent weekly TAX at its MTD. Patients and Methods: Sixty-two patients with histologic diagnosis of GBM were enrolled from 8/16/96 through 3/21/97 in a multi-institutional Phase II trial of EBRT and TAX 225 mg/m 2 /3 h (1-3 h before EBRT), administered the first treatment day of each RT week. Total EBRT dose was 60 Gy (200 cGy/fraction), 5 days per week. A smaller treatment field, to include gross disease plus a margin only, was used after 46 Gy. Results: Sixty-one patients (98%) were evaluable. Median age was 55 years (range, 28-78). Seventy-four percent were ≥50 years. Recursive partitioning analysis (RPA) Classes III, IV, V, VI included 10 (17%), 21 (34%), 25 (41%), and 5 (8%) patients, respectively. Gross total resection was performed in only 16%. There was no Grade 3 or 4 neutropenia or thrombocytopenia. Hypersensitivity reactions precluding further use of TAX occurred in 4 patients. There were 2 instances of late neurotoxicity (4% Grade 3 or 4). Ninety-one percent of patients received treatment per protocol. Seventy-seven percent completed prescribed treatment (6 weeks). Of 35 patients with measurable disease, CR/PR was observed in 23%, MR in 17%, and SD in 43%. Seventeen percent demonstrated progression at first follow-up. Median potential follow-up time is 20 months. Median survival is 9.7 months, with median survivals for RPA classes III, IV, V, and VI of 16.3, 10

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  17. An examination of human factors in external beam radiation therapy: Findings and implications

    International Nuclear Information System (INIS)

    Henriksen, K.; Kaye, R.D.; Jones, R.E. Jr.; Morisseau, D.S.; Persensky, J.J.

    1994-01-01

    To better understand the contributing factors to human error in external beam radiation therapy, the US Nuclear Regulatory Commission has undertaken a series of human factors evaluations. A team of human factors specialists, assisted by a panel of radiation oncologists, medical physicists, and radiation technologists, conducted visits to 24 radiation oncology departments at community hospitals, university centers, and free-standing clinics. A function and task analysis was initially performed to guide subsequent evaluations in the areas of human-system interfaces, procedures, training and qualifications, and organizational policies and practices. Representative findings and implications for improvement are discussed within the context of a dynamic model which holds that misadministration likely results from the unanticipated interaction of several necessary but singly insufficient conditions

  18. 103PD brachytherapy and external beam irradiation for clinically localized, high-risk prostatic carcinoma

    International Nuclear Information System (INIS)

    Dattoli, Michael; Wallner, Kent; Sorace, Richard; Koval, John; Cash, Jennifer; Acosta, Rudolph; Brown, Charles; Etheridge, James; Binder, Michael; Brunelle, Richard; Kirwan, Novelle; Sanchez, Servando; Stein, Douglas; Wasserman, Stuart

    1996-01-01

    Purpose: To summarize biochemical failure rates and morbidity of external beam irradiation (EBRT) combined with palladium ( 103 Pd) boost for clinically localized high-risk prostate carcinoma. Methods and Materials: Seventy-three consecutive patients with stage T2a-T3 prostatic carcinoma were treated from 1991 through 1994. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (71 patients), Gleason score 7-10 (40 patients), prostate specific antigen (PSA) >15 (32 patients), or elevated prostatic acid phosphatase (PAP) (17 patients). Patients received 41 Gy EBRT to a limited pelvic field, followed 4 weeks later by a 103 Pd boost (prescription dose: 80 Gy). Biochemical failure was defined as a PSA greater than 1.0 ng/ml (normal 103 Pd brachytherapy for clinically localized, high-risk prostate cancer compare favorably with that reported after conventional dose EBRT alone. Morbidity has been acceptable

  19. A Bile Duct Cancer Patient Whose Stent Shifted Significantly Over the Course of External Beam Radiotherapy

    International Nuclear Information System (INIS)

    Yun, Hyong Geun

    2011-01-01

    The author reports a bile duct cancer patient whose stent shifted significantly from right to left over the course of radiotherapy. The 80-year-old female patient had a short stature with thoracic kyphosis and mutiple spinal compression fractures. She was also emaciated and very lean. By comparing the weekly scanned computed tomography images, the author found her stent to have shifted by more than 4 cm from right to left over the course of external beam radiotherapy. The results of this case study suggest that for a very lean and emaciated kyphotic bile duct cancer patient, the possibility of large interfractional movement of the bile duct or stent during radiotherapy should be considered.

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

    Directory of Open Access Journals (Sweden)

    Michael A. Sia

    2010-01-01

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

  1. A digital fluoroscopic imaging system for verification during external beam radiotherapy

    International Nuclear Information System (INIS)

    Takai, Michikatsu

    1990-01-01

    A digital fluoroscopic (DF) imaging system has been constructed to obtain portal images for verification during external beam radiotherapy. The imaging device consists of a fluorescent screen viewed by a highly sensitive video camera through a mirror. The video signal is digitized and processed by an image processor which is linked on-line with a host microcomputer. The image quality of the DF system was compared with that of film for portal images of the Burger phantom and the Alderson anthropomorphic phantom using 10 MV X-rays. Contrast resolution of the DF image integrated for 8.5 sec. was superior to the film resolution, while spatial resolution was slightly inferior. The DF image of the Alderson phantom processed by the adaptive histogram equalization was better in showing anatomical landmarks than the film portal image. The DF image integrated for 1 sec. which is used for movie mode can show patient movement during treatment. (author)

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  3. On finding the analytic dependencies of the external field potential on the control function when optimizing the beam dynamics

    Science.gov (United States)

    Ovsyannikov, A. D.; Kozynchenko, S. A.; Kozynchenko, V. A.

    2017-12-01

    When developing a particle accelerator for generating the high-precision beams, the injection system design is of importance, because it largely determines the output characteristics of the beam. At the present paper we consider the injection systems consisting of electrodes with given potentials. The design of such systems requires carrying out simulation of beam dynamics in the electrostatic fields. For external field simulation we use the new approach, proposed by A.D. Ovsyannikov, which is based on analytical approximations, or finite difference method, taking into account the real geometry of the injection system. The software designed for solving the problems of beam dynamics simulation and optimization in the injection system for non-relativistic beams has been developed. Both beam dynamics and electric field simulations in the injection system which use analytical approach and finite difference method have been made and the results presented in this paper.

  4. Treatment of Head and Neck Paragangliomas With External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Dupin, Charles, E-mail: c.dupin@bordeaux.unicancer.fr [Department of Radiotherapy, Comprehensive Cancer Center, Institut Bergonié, Bordeaux (France); Lang, Philippe [Department of Radiotherapy, Pitié Salpétrière, Paris (France); Dessard-Diana, Bernadette [Department of Radiotherapy, Hopital Européen Georges Pompidou, Paris (France); Simon, Jean-Marc; Cuenca, Xavier; Mazeron, Jean-Jacques; Feuvret, Loïc [Department of Radiotherapy, Pitié Salpétrière, Paris (France)

    2014-06-01

    Purpose: To retrospectively assess the outcomes of radiation therapy in patients with head and neck paragangliomas. Methods and Materials: From 1990 to 2009, 66 patients with 81 head and neck paragangliomas were treated by conventional external beam radiation therapy in 25 fractions at a median dose of 45 Gy (range, 41.4-68 Gy). One case was malignant. The median gross target volume and planning target volume were 30 cm{sup 3} (range, 0.9-243 cm{sup 3}) and 116 cm{sup 3} (range, 24-731 cm{sup 3}), respectively. Median age was 57.4 years (range, 15-84 years). Eleven patients had multicentric lesions, and 8 had family histories of paraganglioma. Paragangliomas were located in the temporal bone, the carotid body, and the glomus vagal in 51, 18, and 10 patients, respectively. Forty-six patients had exclusive radiation therapy, and 20 had salvage radiation therapy. The median follow-up was 4.1 years (range, 0.1-21.2 years). Results: One patient had a recurrence of temporal bone paraganglioma 8 years after treatment. The actuarial local control rates were 100% at 5 years and 98.7% at 10 years. Patients with multifocal tumors and family histories were significantly younger (42 years vs 58 years [P=.002] and 37 years vs 58 years [P=.0003], respectively). The association between family predisposition and multifocality was significant (P<.001). Two patients had cause-specific death within the 6 months after irradiation. During radiation therapy, 9 patients required hospitalization for weight loss, nausea, mucositis, or ophthalmic zoster. Two late vascular complications occurred (middle cerebral artery and carotid stenosis), and 2 late radiation-related meningiomas appeared 15 and 18 years after treatment. Conclusion: Conventional external beam radiation therapy is an effective and safe treatment option that achieves excellent local control; it should be considered as a first-line treatment of choice for head and neck paragangliomas.

  5. Serum testosterone levels after external beam radiation for clinically localized prostate cancer

    International Nuclear Information System (INIS)

    Zagars, Gunar K.; Pollack, Alan

    1997-01-01

    Purpose: To determine whether serum total testosterone levels change after external beam radiation therapy for localized prostate cancer. Methods and Materials: Eighty-five men with clinically localized prostate cancer (T1-T3, N0/NX, M0) who underwent external beam radiation therapy without androgen ablation had pretreatment and 3-month posttreatment total serum testosterone levels determined by radioimmunoassay. Scattered doses to the testicles were measured with thermoluminescent dosimetry in 10 men. Results: Pretreatment serum testosterone levels ranged from 185 to 783 ng/dl, with a mean of 400 ng/dl and a median of 390 ng/dl. The coefficient of variation was 30%. Postradiation 3-month testosterone levels ranged from 163 ng/dl to 796 ng/dl, with mean and median values of 356 ng/dl and 327 ng/ml, respectively. The coefficient of variation was 34%. The 3-month value was significantly lower than the pretreatment value (Wilcoxon paired p = 0.0001). The mean absolute fall was 94 ng/dl and the mean percentage fall was 9%. Although the fall in testosterone level was statistically significant, the difference was very small quantitatively. In contrast, serum prostate-specific antigen levels fell dramatically by 3 months after radiation. Testicular scattered doses ranged from 1.84 to 2.42 Gy, with a mean of 2.07 Gy for a prostatic tumor dose of 68 Gy. Conclusions: Although significant, the fall in serum testosterone level after radiation for localized prostate cancer was small and likely of no pathophysiologic consequence. It is unlikely that scattered testicular radiation plays any significant role in the genesis of this change in testosterone level, which most likely occurs as a nonspecific stress response

  6. Treatment of Head and Neck Paragangliomas With External Beam Radiation Therapy

    International Nuclear Information System (INIS)

    Dupin, Charles; Lang, Philippe; Dessard-Diana, Bernadette; Simon, Jean-Marc; Cuenca, Xavier; Mazeron, Jean-Jacques; Feuvret, Loïc

    2014-01-01

    Purpose: To retrospectively assess the outcomes of radiation therapy in patients with head and neck paragangliomas. Methods and Materials: From 1990 to 2009, 66 patients with 81 head and neck paragangliomas were treated by conventional external beam radiation therapy in 25 fractions at a median dose of 45 Gy (range, 41.4-68 Gy). One case was malignant. The median gross target volume and planning target volume were 30 cm 3 (range, 0.9-243 cm 3 ) and 116 cm 3 (range, 24-731 cm 3 ), respectively. Median age was 57.4 years (range, 15-84 years). Eleven patients had multicentric lesions, and 8 had family histories of paraganglioma. Paragangliomas were located in the temporal bone, the carotid body, and the glomus vagal in 51, 18, and 10 patients, respectively. Forty-six patients had exclusive radiation therapy, and 20 had salvage radiation therapy. The median follow-up was 4.1 years (range, 0.1-21.2 years). Results: One patient had a recurrence of temporal bone paraganglioma 8 years after treatment. The actuarial local control rates were 100% at 5 years and 98.7% at 10 years. Patients with multifocal tumors and family histories were significantly younger (42 years vs 58 years [P=.002] and 37 years vs 58 years [P=.0003], respectively). The association between family predisposition and multifocality was significant (P<.001). Two patients had cause-specific death within the 6 months after irradiation. During radiation therapy, 9 patients required hospitalization for weight loss, nausea, mucositis, or ophthalmic zoster. Two late vascular complications occurred (middle cerebral artery and carotid stenosis), and 2 late radiation-related meningiomas appeared 15 and 18 years after treatment. Conclusion: Conventional external beam radiation therapy is an effective and safe treatment option that achieves excellent local control; it should be considered as a first-line treatment of choice for head and neck paragangliomas

  7. External beam radiotherapy for subretinal neovascularization in age-related macular degeneration: is this treatment efficient?

    International Nuclear Information System (INIS)

    Staar, Susanne; Krott, Ralf; Mueller, Rolf-Peter; Bartz-Schmidt, Karl U.; Heimann, Klaus

    1999-01-01

    Purpose: Control of the natural course of sub retinal neovascularization (SRNV) in age-related macular degeneration (AMD) is difficult. Only a subset of patients is suitable for laser coagulation. This prospective study aimed to determine the efficacy and individual benefit of external beam radiotherapy (EBRT). Methods and Materials: The prospective trial included 287 patients with subfoveal neovascularization due to AMD which was verified by fluorescein angiography. Patients have been treated between January 1996 and October 1997. All patients received a total dose of 16 Gy in 2-Gy daily fractions with 5-6 MeV photons based on computerized treatment planning in individual head mask fixation. This first analysis is based on 73 patients (50 women, 23 men, median age 74.3 years), with a median follow-up of 13.3 months and a minimum follow-up of 11 months. Results: All patients completed therapy and tolerability was good. First clinical control with second angiography was performed 6 weeks after irradiation, then in 3-month intervals. Eighteen patients with SRNV refusing radiotherapy served as a control group and were matched with 18 irradiated patients. After 7 months median visual acuity (VA) was 20/160 for the irradiated and 20/400 for the untreated patients. One year after radiotherapy final median VA was 20/400 in both groups. Conclusion: These results suggest that 16 Gy of conventionally fractionated external beam irradiation slows down the visual loss in exudative AMD for only a few months. Patients' reading vision could not be saved for a long-term run

  8. External beam radiation therapy for squamous cell carcinoma of the soft palate

    International Nuclear Information System (INIS)

    Medini, Eitan; Medini, Allen; Gapany, Markus; Levitt, Seymour H.

    1997-01-01

    Purpose: External beam radiation therapy for carcinoma of the soft palate aims to achieve loco-regional control with normal speech, nasal function, swallowing mechanism, and minimal side effects such as nasal speech and regurgitation of food into the nasopharynx. In this report we present our results of radiotherapy in the treatment of 24 patients with squamous cell carcinoma of the soft palate. Methods and Materials: A total of 24 patients with squamous cell carcinoma of the soft palate were treated at the Veterans Administration Medical Center Minneapolis, MN, between February 1977 and May 1992. Of the 24 patients 2 had T1, 19 T2, 1 T3, and 2 had T4 lesions. Nineteen patients did not have clinical nodal disease, stage (N0), 1 had N1, 2 N2, and 2 N3 disease (Table 1). All the patients were treated by 4 MeV linear accelerator. A 1.75 Gy median dose was administered per fraction to a total of 70 Gy median dose. Bilateral opposed compensated shrinking fields technique was used. Results: The 3-year disease free survival rate after external beam radiation therapy was 100% (1 out of 1), 64.7% (11 out of 17), 100% (1 out of 1), and 0%, for patients with T1, T2, T3, and T4 disease, respectively. Salvage surgery for recurrent disease was successful in 57.1% (4 out of 7 patients). The ultimate 3-year disease free survival rate for the entire group, including surgical salvage, was 81% (17 out of 21). Conclusion: Radiation therapy alone in our institution resulted in tumor control and survival rates compare favorably to previously published reports in the literature. Surgery can be reserved as salvage procedure

  9. Propagation characteristics of a focused laser beam in a strontium barium niobate photorefractive crystal under reverse external electric field.

    Science.gov (United States)

    Guo, Q L; Liang, B L; Wang, Y; Deng, G Y; Jiang, Y H; Zhang, S H; Fu, G S; Simmonds, P J

    2014-10-01

    The propagation characteristics of a focused laser beam in a SBN:75 photorefractive crystal strongly depend on the signal-to-background intensity ratio (R=Is/Ib) under reverse external electric field. In the range 20>R>0.05, the laser beam shows enhanced self-defocusing behavior with increasing external electric field, while it shows self-focusing in the range 0.03>R>0.01. Spatial solitons are observed under a suitable reverse external electric field for R=0.025. A theoretical model is proposed to explain the experimental observations, which suggest a new type of soliton formation due to "enhancement" not "screening" of the external electrical field.

  10. The external beam facility used to characterize corrosion products in metallic statuettes

    International Nuclear Information System (INIS)

    Rizzutto, M.A.; Tabacniks, M.H.; Added, N.; Barbosa, M.D.L.; Curado, J.F.; Santos, W.A.; Lima, S.C.; Melo, H.G.; Neiva, A.C.

    2005-01-01

    To open new possibilities in nuclear applied physics research, mainly for the analysis of art objects in air, an external beam facility was installed at LAMFI (Laboratorio de Analise de Materiais por Feixes Ionicos) of University of Sao Paulo. PIXE measurements were made using an XR-100CR (Si-PIN) X-ray detector pointed to the sample mounted after an approximate 11 mm air path, hence with effective beam energy of 0.9 MeV. This setup was used to characterize the corrosion products of two ethnological metallic statuettes from the African collection of the Museum of Archaeology and Etnology. PIXE analysis of the corrosion free base of one statuette showed that Cu and Zn are the main components of the alloy, while Pb is present in smaller amount. The analysis of some corrosion products showed a Zn:Cu relationship higher than that of the base, evidencing selective corrosion. The main components of the other statuette were Cu and Pb, while S and Zn were found in smaller amounts

  11. External beam radiotherapy of localized prostatic adenocarcinoma. Evaluation of conformal therapy, field number and target margins

    International Nuclear Information System (INIS)

    Lennernaes, B.; Rikner, G.; Letocha, H.; Nilsson, S.

    1995-01-01

    The purpose of the present study was to identify factors of importance in the planning of external beam radiotherapy of prostatic adenocarcinoma. Seven patients with urogenital cancers were planned for external radiotherapy of the prostate. Four different techniques were used, viz. a 4-field box technique and four-, five- or six-field conformal therapy set-ups combined with three different margins (1-3 cm). The evaluations were based on the doses delivered to the rectum and the urinary bladder. A normal tissue complication probability (NTCP) was calculated for each plan using Lyman's dose volume reduction method. The most important factors that resulted in a decrease of the dose delivered to the rectum and the bladder were the use of conformal therapy and smaller margins. Conformal therapy seemed more important for the dose distribution in the urinary bladder. Five- and six-field set-ups were not significantly better than those with four fields. NTCP calculations were in accordance with the evaluation of the dose volume histograms. To conclude, four-field conformal therapy utilizing reduced margins improves the dose distribution to the rectum and the urinary bladder in the radiotherapy of prostatic adenocarcinoma. (orig.)

  12. Accuracy of digital peripical radiography and cone-beam computed tomography in detecting external root resorption

    Energy Technology Data Exchange (ETDEWEB)

    Creanga, Adriana Gabriela [Division of Dental Diagnostic Science, Rutgers School of Dental Medicine, Newark (United States); Geha, Hassem; Sankar, Vidya; Mcmahan, Clyde Alex; Noujeim, Marcel [University of Texas Health Science Center San Antonio, San Antonio (United States); Teixeira, Fabrico B. [Dept. of Endodontics, University of Iowa, Iowa City (United States)

    2015-09-15

    The purpose of this study was to evaluate and compare the efficacy of cone-beam computed tomography (CBCT) and digital intraoral radiography in diagnosing simulated small external root resorption cavities. Cavities were drilled in 159 roots using a small spherical bur at different root levels and on all surfaces. The teeth were imaged both with intraoral digital radiography using image plates and with CBCT. Two sets of intraoral images were acquired per tooth: orthogonal (PA) which was the conventional periapical radiograph and mesioangulated (SET). Four readers were asked to rate their confidence level in detecting and locating the lesions. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of each modality in detecting the presence of lesions, the affected surface, and the affected level. Analysis of variation was used to compare the results and kappa analysis was used to evaluate interobserver agreement. A significant difference in the area under the ROC curves was found among the three modalities (P=0.0002), with CBCT (0.81) having a significantly higher value than PA (0.71) or SET (0.71). PA was slightly more accurate than SET, but the difference was not statistically significant. CBCT was also superior in locating the affected surface and level. CBCT has already proven its superiority in detecting multiple dental conditions, and this study shows it to likewise be superior in detecting and locating incipient external root resorption.

  13. Successful delivery of adjuvant external beam radiotherapy for ependymoma in a patient with Ondine's curse

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Mehee [Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL (United States); Thoma, Miranda; Tolekidis, George [Department of Radiation Oncology, Rush University Medical Center, Chicago, IL (United States); Byrne, Richard W. [Department of Neurosurgery, Rush University Medical Center, Chicago, IL (United States); Diaz, Aidnag Z., E-mail: aidnag_diaz@rush.edu [Department of Radiation Oncology, Rush University Medical Center, Chicago, IL (United States); Department of Neurosurgery, Rush University Medical Center, Chicago, IL (United States)

    2015-01-01

    Ondine's curse is a rare, potentially life-threatening disorder characterized by loss of automatic breathing during sleep and preserved voluntary breathing. It is seldom encountered in the radiotherapy clinic but can pose significant technical challenges and safety concerns in the delivery of a prescribed radiation course. We report a unique case of successful delivery of radiotherapy for ependymoma in a patient with Ondine's curse. A 53-year-old gentleman presented with vertigo when lying down. Brain magnetic resonance imaging revealed an enhancing mass in the floor of the fourth ventricle. He underwent maximal safe resection. Pathology revealed ependymoma. The patient was referred for radiotherapy. Computed tomography simulation was performed in supine position with 3-point thermoplastic mask immobilization. Sequential TomoTherapy plans were developed. At first scheduled treatment, shortly after mask placement, his arms went limp and he was unresponsive. Vitals showed oxygen saturation 83%, pulse 127, and blood pressure 172/97 mm Hg. He was diagnosed with Ondine's curse thought secondary to previous brainstem damage; the combination of lying flat and pressure from the mask was causing him to go into respiratory arrest. As supine positioning did not seem clinically advisable, he was simulated in prone position. A RapidArc plan and a back-up conformal plan were developed. Prescriptions were modified to meet conservative organs-at-risk constraints. Several strategies were used to minimize uncertainties in set-up reproducibility associated with prone positioning. He tolerated prone RapidArc treatments well. The report highlights the importance of applying practical patient safety and treatment planning/delivery strategies in the management of this challenging case.

  14. SU-E-T-577: Commissioning of a Deterministic Algorithm for External Photon Beams

    International Nuclear Information System (INIS)

    Zhu, T; Finlay, J; Mesina, C; Liu, H

    2014-01-01

    Purpose: We report commissioning results for a deterministic algorithm for external photon beam treatment planning. A deterministic algorithm solves the radiation transport equations directly using a finite difference method, thus improve the accuracy of dose calculation, particularly under heterogeneous conditions with results similar to that of Monte Carlo (MC) simulation. Methods: Commissioning data for photon energies 6 – 15 MV includes the percentage depth dose (PDD) measured at SSD = 90 cm and output ratio in water (Spc), both normalized to 10 cm depth, for field sizes between 2 and 40 cm and depths between 0 and 40 cm. Off-axis ratio (OAR) for the same set of field sizes was used at 5 depths (dmax, 5, 10, 20, 30 cm). The final model was compared with the commissioning data as well as additional benchmark data. The benchmark data includes dose per MU determined for 17 points for SSD between 80 and 110 cm, depth between 5 and 20 cm, and lateral offset of up to 16.5 cm. Relative comparisons were made in a heterogeneous phantom made of cork and solid water. Results: Compared to the commissioning beam data, the agreement are generally better than 2% with large errors (up to 13%) observed in the buildup regions of the FDD and penumbra regions of the OAR profiles. The overall mean standard deviation is 0.04% when all data are taken into account. Compared to the benchmark data, the agreements are generally better than 2%. Relative comparison in heterogeneous phantom is in general better than 4%. Conclusion: A commercial deterministic algorithm was commissioned for megavoltage photon beams. In a homogeneous medium, the agreement between the algorithm and measurement at the benchmark points is generally better than 2%. The dose accuracy for a deterministic algorithm is better than a convolution algorithm in heterogeneous medium

  15. Finite Element Simulation of GFRP Reinforced Concrete Beam Externally Strengthened With CFRP Plates

    Directory of Open Access Journals (Sweden)

    Salleh Norhafizah

    2017-01-01

    Full Text Available The construction technology now has become more and more advanced allowing the development of new technologies or material to replace the previous one and also solved some of the troubles confronted by construction experts. The Glass Fibre Reinforced Polymer (GFRP composite is an alternative to replace the current usage of steel as it is rust proof and stronger in terms of stiffness compared to steel. Furthermore, GFRP bars have a high strength-to-weight ratio, making them attractive as reinforcement for concrete structures. However, the tensile behavior of GFRP bars is characterized by a linear elastic stress–strain relationship up to failure and, therefore, concrete elements reinforced with GFRP reinforcement exhibit brittle failure without warning. Design codes encourage over-reinforced GFRP design since it is more progressive and leads to a less catastrophic failure with a higher degree of deformability. Moreover, because of GFRP low modulus of elasticity, GFRP reinforced concrete members exhibit larger deflections and wider cracks width than steel reinforced concrete. This aims of this paper is to developed 2D Finite Element (FE models that can accurately simulate the respond on an improvement in the deflection of GFRP reinforced concrete beam externally strengthened with CFRP plates on the tension part of beam. The prediction of flexural response according to RCCSA software was also discussed. It was observed that the predicted FE results are given similar result with the experimental measured test data. Base on this good agreement, a parametric study was the performed using the validation FE model to investigate the effect of flexural reinforcement ratio and arrangement of the beams strengthened with different regions of CFRP plates.

  16. Non-rigid CT/CBCT to CBCT registration for online external beam radiotherapy guidance

    Science.gov (United States)

    Zachiu, Cornel; de Senneville, Baudouin Denis; Tijssen, Rob H. N.; Kotte, Alexis N. T. J.; Houweling, Antonetta C.; Kerkmeijer, Linda G. W.; Lagendijk, Jan J. W.; Moonen, Chrit T. W.; Ries, Mario

    2018-01-01

    Image-guided external beam radiotherapy (EBRT) allows radiation dose deposition with a high degree of accuracy and precision. Guidance is usually achieved by estimating the displacements, via image registration, between cone beam computed tomography (CBCT) and computed tomography (CT) images acquired at different stages of the therapy. The resulting displacements are then used to reposition the patient such that the location of the tumor at the time of treatment matches its position during planning. Moreover, ongoing research aims to use CBCT-CT image registration for online plan adaptation. However, CBCT images are usually acquired using a small number of x-ray projections and/or low beam intensities. This often leads to the images being subject to low contrast, low signal-to-noise ratio and artifacts, which ends-up hampering the image registration process. Previous studies addressed this by integrating additional image processing steps into the registration procedure. However, these steps are usually designed for particular image acquisition schemes, therefore limiting their use on a case-by-case basis. In the current study we address CT to CBCT and CBCT to CBCT registration by the means of the recently proposed EVolution registration algorithm. Contrary to previous approaches, EVolution does not require the integration of additional image processing steps in the registration scheme. Moreover, the algorithm requires a low number of input parameters, is easily parallelizable and provides an elastic deformation on a point-by-point basis. Results have shown that relative to a pure CT-based registration, the intrinsic artifacts present in typical CBCT images only have a sub-millimeter impact on the accuracy and precision of the estimated deformation. In addition, the algorithm has low computational requirements, which are compatible with online image-based guidance of EBRT treatments.

  17. Cobalt-60 Machines and Medical Linear Accelerators: Competing Technologies for External Beam Radiotherapy.

    Science.gov (United States)

    Healy, B J; van der Merwe, D; Christaki, K E; Meghzifene, A

    2017-02-01

    Medical linear accelerators (linacs) and cobalt-60 machines are both mature technologies for external beam radiotherapy. A comparison is made between these two technologies in terms of infrastructure and maintenance, dosimetry, shielding requirements, staffing, costs, security, patient throughput and clinical use. Infrastructure and maintenance are more demanding for linacs due to the complex electric componentry. In dosimetry, a higher beam energy, modulated dose rate and smaller focal spot size mean that it is easier to create an optimised treatment with a linac for conformal dose coverage of the tumour while sparing healthy organs at risk. In shielding, the requirements for a concrete bunker are similar for cobalt-60 machines and linacs but extra shielding and protection from neutrons are required for linacs. Staffing levels can be higher for linacs and more staff training is required for linacs. Life cycle costs are higher for linacs, especially multi-energy linacs. Security is more complex for cobalt-60 machines because of the high activity radioactive source. Patient throughput can be affected by source decay for cobalt-60 machines but poor maintenance and breakdowns can severely affect patient throughput for linacs. In clinical use, more complex treatment techniques are easier to achieve with linacs, and the availability of electron beams on high-energy linacs can be useful for certain treatments. In summary, there is no simple answer to the question of the choice of either cobalt-60 machines or linacs for radiotherapy in low- and middle-income countries. In fact a radiotherapy department with a combination of technologies, including orthovoltage X-ray units, may be an option. Local needs, conditions and resources will have to be factored into any decision on technology taking into account the characteristics of both forms of teletherapy, with the primary goal being the sustainability of the radiotherapy service over the useful lifetime of the equipment

  18. Preparation Of Thermoluminescence Dosimeters For External Radiotherapy Beam Audit In Malaysia

    International Nuclear Information System (INIS)

    Norhayati Abdullah; Siti Sara Deraman; Taiman Kadni; Mohd Taufik Dollah; Norhayati Salleh

    2014-01-01

    The external beam audit is a part of the Quality Assurance Programme (QAP) in radiotherapy that should be carried out to check the accuracy of dose delivered by the radiotherapy treatment units are within the tolerance limit of A ± 5 % as recommended by the International Commission of Radiation Units and Measurements (ICRU) Report No. 24. In this work, thermoluminescence dosimeters (TLD) in powder form were chosen to be used in the dose quality audit for the radiotherapy treatment units in Malaysia. As a preparation, the characterizations of a new batch of TLD-100 powders were studied. The studies include checks for the response of TLD-100 before and after pre-annealing process, reproducibility and linearity of TL signal. Results show that the response of TLD-100 powder after pre-annealing increases by 65 % compared with before pre-annealing process. These TLD-100 powders also provide reliable and consistent readings for the absorbed dose to water within the range of 150 cGy to 250 cGy with the maximum standard uncertainty of 0.554 μC. Finally, the calibration curves for 6 MV and 10 MV photon beams were established. These curves will be used in determining the absorbed dose to water (Dw) from user's irradiated TLDs. The expanded uncertainty (coverage factor k=2) of Dw determination was estimated to be 4.1 %. As a conclusion, these TLD-100 powders are ready to be used as a transfer detector for evaluating the accuracy of user's delivery dose in the radiotherapy beam audit program in Malaysia. (author)

  19. External beam irradiation inhibits neointimal hyperplasia after injury-induced arterial smooth muscle cell proliferation

    International Nuclear Information System (INIS)

    Schaefer, U.; Micke, O.; Dorszewski, A.; Breithardt, G.; Willich, N.

    1996-01-01

    Purpose/Objective: Restenosis after catheter-based revascularization has been demonstrated to be primarily caused by smooth muscle cell proliferation. This study examines the effects of external beam irradiation on neointimal proliferation after external injury to the central artery of the rabbit ear. Materials and Methods: 30 male New Zealand White rabbits were used in this study. Crush lesions were performed on each ear under general anesthesia and bilateral auricular nerve blockade. A single dose of 12 Gy (n=10), 16 Gy (n=10), or 20 Gy (n=10) gamma radiation was delivered to the left or right central artery of the ear 24 hours after injury; the contralateral central artery served as control. All rabbits were sacrificed after twenty-one days and the central arteries of the ear were fixed for morphometric measurements. Results: Mean (± SD) neointimal area was 0.062 ± 0.005 mm 2 (12 Gy), 0.022 ± 0.005 mm 2 (16 Gy) and 0.028 ± 0.006 mm 2 in irradiated arteries compared with 0.081 ± 0.009 mm 2 in the control group. Mean (± SD) luminal area was 0.049 ± 0.004 mm 2 (12 Gy), 0.059 ± 0.002 mm 2 (16 Gy) and 0.072 ± 0.006 mm 2 (24 Gy) in irradiated arteries compared with 0.043 ± 0.008 mm 2 in the control group. The difference in neointimal and luminal area between control and irradiated arteries was significant (p<0.05) only for the 16 and 20 Gy group compared to control. Conclusion: We conclude that in this model, external beam X-ray irradiation was successful in reducing neointimal proliferation after injury of the central artery of the rabbit ear. Marked reductions in neointimal proliferation were demonstrated in vessels subjected to 16 and 20 Gy radiation, a less prominent effect was noted for 12 Gy. Whether this approach can be used successfully to inhibit restenosis in the clinical setting requires further investigation

  20. External beam milli-PIXE as analytical tool for Neolithic obsidian provenance studies

    Energy Technology Data Exchange (ETDEWEB)

    Constantinescu, B.; Cristea-Stan, D. [National Institute for Nuclear Physics and Engineering Horia Hulubei, Bucharest-Magurele (Romania); Kovács, I.; Szõkefalvi-Nagy, Z. [Wigner Research Centre for Phyics, Institute for Particle and Nuclear Physics, Budapest (Hungary)

    2013-07-01

    Full text: Obsidian is the most important archaeological material used for tools and weapons before metals appearance. Its geological sources are limited and concentrated in few geographical zones: Armenia, Eastern Anatolia, Italian Lipari and Sardinia islands, Greek Melos and Yali islands, Hungarian and Slovak Tokaj Mountains. Due to this fact, in Mesolithic and Neolithic periods obsidian was the first archaeological material intensively traded even at long distances. To determine the geological provenance of obsidian and to identify the prehistoric long-range trade routes and possible population migrations elemental concentration ratios can help a 101, since each geological source has its 'fingerprints'. In this work external milli-PIXE technique was applied for elemental concentration ratio determinations in some Neolithic tools found in Transylvania and in the lron Gales region near Danube, and on few relevant geological samples (Slovak Tokaj Mountains, Lipari,Armenia). In Transylvania (the North-Western part of Romania, a region surrounded by Carpathian Mountains), Neolithic obsidian tools were discovered mainly in three regions: North-West - Oradea (near the border with Hungary, Slovakia and Ukraine), Centre -Cluj and Southwest- Banat (near the border with Serbia). A special case is lron Gales - Mesolithic and Early Neolithic sites, directly related to the appearance of agriculture replacing the Mesolithic economy based on hunting and fishing. Three long-distance trade routes could be considered: from Caucasus Mountains via North of the Black Sea, from Greek islands or Asia Minor via ex-Yugoslavia area or via Greece-Bulgaria or from Central Europe- Tokaj Mountains in the case of obsidian. As provenance 'fingerprints', we focused on Ti to Mn, and Rb-Sr-Y-Zr ratios. The measurements were performed at the external milli-PIXE beam-line of the 5MV VdG accelerator of the Wigner RCP. Proton energy of 3MeV and beam currents in the range of 1 ±1 D

  1. A comparison of two methods for estimating the technical costs of external beam radiation therapy

    International Nuclear Information System (INIS)

    Hayman, James A.; Lash, Kathy A.; Tao, May L.; Halman, Marc A.

    2000-01-01

    Purpose: To accurately assess the cost-effectiveness of treatment with external beam radiation, it is necessary to have accurate estimates of its cost. One of the most common methods for estimating technical costs has been to convert Medicare charges into costs using Medicare Cost-to-Charge Ratios (CCR). More recently, health care organizations have begun to invest in sophisticated cost-accounting systems (CAS) that are capable of providing procedure-specific cost estimates. The purpose of this study was to examine whether these competing approaches result in similar cost estimates for four typical courses of external beam radiation therapy (EBRT). Methods and Materials: Technical costs were estimated for the following treatment courses: 1) a palliative 'simple' course of 10 fractions using a single field without blocks; 2) a palliative 'complex' course of 10 fractions using two opposed fields with custom blocks; 3) a curative course of 30 fractions for breast cancer using tangent fields followed by an electron beam boost; and 4) a curative course of 35 fractions for prostate cancer using CT-planning and a 4-field technique. Costs were estimated using the CCR approach by multiplying the number of units of each procedure billed by its Medicare charge and CCR and then summing these costs. Procedure-specific cost estimates were obtained from a cost-accounting system, and overall costs were then estimated for the CAS approach by multiplying the number of units billed by the appropriate unit cost estimate and then summing these costs. All costs were estimated using data from 1997. The analysis was also repeated using data from another academic institution to estimate their costs using the CCR and CAS methods, as well as the appropriate relative value units (RVUs) and conversion factor from the 1997 Medicare Fee Schedule to estimate Medicare reimbursement for the four treatment courses. Results: The estimated technical costs for the CCR vs. CAS approaches for the four

  2. External beam milli-PIXE as analytical tool for Neolithic obsidian provenance studies

    International Nuclear Information System (INIS)

    Constantinescu, B.; Cristea-Stan, D.; Kovács, I.; Szõkefalvi-Nagy, Z.

    2013-01-01

    Full text: Obsidian is the most important archaeological material used for tools and weapons before metals appearance. Its geological sources are limited and concentrated in few geographical zones: Armenia, Eastern Anatolia, Italian Lipari and Sardinia islands, Greek Melos and Yali islands, Hungarian and Slovak Tokaj Mountains. Due to this fact, in Mesolithic and Neolithic periods obsidian was the first archaeological material intensively traded even at long distances. To determine the geological provenance of obsidian and to identify the prehistoric long-range trade routes and possible population migrations elemental concentration ratios can help a 101, since each geological source has its 'fingerprints'. In this work external milli-PIXE technique was applied for elemental concentration ratio determinations in some Neolithic tools found in Transylvania and in the lron Gales region near Danube, and on few relevant geological samples (Slovak Tokaj Mountains, Lipari,Armenia). In Transylvania (the North-Western part of Romania, a region surrounded by Carpathian Mountains), Neolithic obsidian tools were discovered mainly in three regions: North-West - Oradea (near the border with Hungary, Slovakia and Ukraine), Centre -Cluj and Southwest- Banat (near the border with Serbia). A special case is lron Gales - Mesolithic and Early Neolithic sites, directly related to the appearance of agriculture replacing the Mesolithic economy based on hunting and fishing. Three long-distance trade routes could be considered: from Caucasus Mountains via North of the Black Sea, from Greek islands or Asia Minor via ex-Yugoslavia area or via Greece-Bulgaria or from Central Europe- Tokaj Mountains in the case of obsidian. As provenance 'fingerprints', we focused on Ti to Mn, and Rb-Sr-Y-Zr ratios. The measurements were performed at the external milli-PIXE beam-line of the 5MV VdG accelerator of the Wigner RCP. Proton energy of 3MeV and beam currents in the range of 1 ±1 D

  3. Accelerated partial breast irradiation with external beam radiotherapy. First results of the German phase 2 trial

    Energy Technology Data Exchange (ETDEWEB)

    Ott, Oliver J.; Strnad, Vratislav; Stillkrieg, Wilhelm; Fietkau, Rainer [University Hospital Erlangen, Department of Radiation Oncology, Erlangen (Germany); Uter, Wolfgang [University Erlangen-Nuremberg, Dept. of Medical Informatics, Biometry and Epidemiology, Erlangen (Germany); Beckmann, Matthias W. [University Hospital Erlangen, Dept. of Gynecology, Erlangen (Germany)

    2017-01-15

    To evaluate the feasibility and efficacy of external beam three-dimensional (3D) conformal accelerated partial breast irradiation (APBI) for selected patients with early breast cancer. Between 2011 and 2016, 72 patients were recruited for this prospective phase 2 trial. Patients were eligible for APBI if they had histologically confirmed breast cancer or pure ductal carcinoma in situ (DCIS), a tumor diameter ≤3 cm, clear resection margins ≥2 mm, no axillary lymph node involvement, no distant metastases, tumor bed clips, and were aged ≥50 years. Patients were excluded if mammography showed a multicentric invasive growth pattern, or if they had residual diffuse microcalcifications postoperatively, an extensive intraductal component, or vessel invasion. Patients received 3D conformal external beam APBI with a total dose of 38 Gy in 10 fractions in 1-2 weeks. The trial had been registered at the German Clinical Trials Register, DRKS-ID: DRKS00004417. Median follow-up was 25.5 months (range 1-61 months). Local control was maintained in 71 of 72 patients. The 3-year local recurrence rate was 2.1% (95% confidence interval, CI: 0-6.1%). Early toxicity (grade 1 radiodermatitis) was seen in 34.7% (25/72). Late side effects ≥ grade 3 did not occur. Cosmetic results were rated as excellent/good in 96.7% (59/61). APBI with external beam radiotherapy techniques is feasible with low toxicity and, according to the results of the present and other studies, on the way to becoming a standard treatment option for a selected subgroup of patients. (orig.) [German] Untersuchung der Vertraeglichkeit und Sicherheit der externen, 3-D-konformalen akzelerierten Teilbrustbestrahlung (APBI) fuer ausgewaehlte Patientinnen mit einem fruehen Mammakarzinom. Von 2011 bis 2016 wurden 72 Patientinnen in diese prospektive Phase-2-Studie eingebracht. Einschlusskriterien waren ein histologisch gesichertes Mammakarzinom oder DCIS, ein Tumordurchmesser ≤ 3 cm, tumorfreie Resektionsraender ≥ 2

  4. Strengthening of Reinforced Concrete Beam in Shear Zone by Compensation the Stirrups with Equivalent External Steel Plates

    Directory of Open Access Journals (Sweden)

    Khamail Abdul-Mahdi Mosheer

    2016-09-01

    Full Text Available An experimental study on reinforced concrete beams strengthened with external steel plates instead of shear stirrups has been held in this paper. Eight samples of the same dimensions and properties were used. Two of them were tested up to failure and specified as references beams; one with shear reinforcement and the other without shear reinforcement. Another samples without shear reinforcement were tested until the first shear crack occurs, then the samples strengthened on both sides with external steel plates as equivalent area of removed stirrups. The strengthened beams were divided into three groups according to the thickness of plates (1, 1.5, 2 mm, each group involved two beams; one bonded using epoxy and the other bonded using epoxy with anchored bolts. Finally, the strengthened beams tested when using anchored bolts with epoxy glue to bond plates. Where the increasing in maximum load is higher than that in reference beam with no internal stirrups reach to (75.46 –106.13% and has a good agreement with the control beam with shear reinforcement reach to (76.06 – 89.36% of ultimate load.

  5. Optimum location of external markers using feature selection algorithms for real-time tumor tracking in external-beam radiotherapy: a virtual phantom study.

    Science.gov (United States)

    Nankali, Saber; Torshabi, Ahmad Esmaili; Miandoab, Payam Samadi; Baghizadeh, Amin

    2016-01-08

    In external-beam radiotherapy, using external markers is one of the most reliable tools to predict tumor position, in clinical applications. The main challenge in this approach is tumor motion tracking with highest accuracy that depends heavily on external markers location, and this issue is the objective of this study. Four commercially available feature selection algorithms entitled 1) Correlation-based Feature Selection, 2) Classifier, 3) Principal Components, and 4) Relief were proposed to find optimum location of external markers in combination with two "Genetic" and "Ranker" searching procedures. The performance of these algorithms has been evaluated using four-dimensional extended cardiac-torso anthropomorphic phantom. Six tumors in lung, three tumors in liver, and 49 points on the thorax surface were taken into account to simulate internal and external motions, respectively. The root mean square error of an adaptive neuro-fuzzy inference system (ANFIS) as prediction model was considered as metric for quantitatively evaluating the performance of proposed feature selection algorithms. To do this, the thorax surface region was divided into nine smaller segments and predefined tumors motion was predicted by ANFIS using external motion data of given markers at each small segment, separately. Our comparative results showed that all feature selection algorithms can reasonably select specific external markers from those segments where the root mean square error of the ANFIS model is minimum. Moreover, the performance accuracy of proposed feature selection algorithms was compared, separately. For this, each tumor motion was predicted using motion data of those external markers selected by each feature selection algorithm. Duncan statistical test, followed by F-test, on final results reflected that all proposed feature selection algorithms have the same performance accuracy for lung tumors. But for liver tumors, a correlation-based feature selection algorithm, in

  6. Research of transportation efficiency of low-energy high- current electron beam in plasma channel in external magnetic field

    International Nuclear Information System (INIS)

    Vagin, E S; Grigoriev, V P

    2015-01-01

    Effective high current (5-20 kA) and low energy (tens of keV) electrons beam transportation is possible only with almost complete charging neutralization. It is also necessary to use quite high current neutralization for elimination beam self-pinching effect. The research is based on the self-consistent mathematical model that takes into account beam and plasma particles dynamic, current and charge neutralization of electron beam and examines the transportation of electron beam into a chamber with low-pressure plasma in magnetic field. A numerical study was conducted using particle in cell (PIC) method. The study was performed with various system parameters: rise time and magnitude of the beam current, gas pressure and plasma density and geometry of the system. Regularities of local virtual cathode field generated by the beam in the plasma channel, as well as ranges of parameters that let transportation beam with minimal losses, depending on the external magnetic field were determined through a series of numerical studies. In addition, the assessment of the impact of the plasma ion mobility during the transition period and during steady beam was performed. (paper)

  7. Muscle invasive bladder cancer treated by transurethral resection, followed by external beam radiation and interstitial iridium-192

    NARCIS (Netherlands)

    A. Wijnmaalen (Arendjan); P.A. Helle (Peter); P.C.M. Koper (Peter); P.P. Jansen (Peter); P. Hanssens (Patrick); C.G.G. Boeken Kruger (Cornelis); W.L.J. van Putten (Wim)

    1997-01-01

    textabstractPurpose: To evaluate the results of transurethral resection (TUR), external beam radiotherapy (EBRT), and interstitial radiation (IRT) with iridium-192, using the afterloading technique in patients with muscle invasive bladder cancer. Methods and Materials: From May 1989 until September

  8. ACR Appropriateness Criteria for external beam radiation therapy treatment planning for clinically localized prostate cancer, part II of II

    Directory of Open Access Journals (Sweden)

    Nicholas G. Zaorsky, MD

    2017-07-01

    Conclusions: External beam radiation is a key component of the curative management of T1 and T2 prostate cancer. By combining the most recent medical literature, these Appropriateness Criteria can aid clinicians in determining the appropriate treatment delivery and personalized approaches for individual patients.

  9. Effect of external magnetic field on critical current for the onset of virtual cathode oscillations in relativistic electron beams

    International Nuclear Information System (INIS)

    Hramov, Alexander; Koronovskii, Alexey; Morozov, Mikhail; Mushtakov, Alexander

    2008-01-01

    In this Letter we research the space charge limiting current value at which the oscillating virtual cathode is formed in the relativistic electron beam as a function of the external magnetic field guiding the beam electrons. It is shown that the space charge limiting (critical) current decreases with growth of the external magnetic field, and that there is an optimal induction value of the magnetic field at which the critical current for the onset of virtual cathode oscillations in the electron beam is minimum. For the strong external magnetic field the space charge limiting current corresponds to the analytical relation derived under the assumption that the motion of the electron beam is one-dimensional [D.J. Sullivan, J.E. Walsh, E. Coutsias, in: V.L. Granatstein, I. Alexeff (Eds.), Virtual Cathode Oscillator (Vircator) Theory, in: High Power Microwave Sources, vol. 13, Artech House Microwave Library, 1987, Chapter 13]. Such behavior is explained by the characteristic features of the dynamics of electron space charge in the longitudinal and radial directions in the drift space at the different external magnetic fields

  10. Evaluation of surface and shallow depth dose reductions using a Superflab bolus during conventional and advanced external beam radiotherapy.

    Science.gov (United States)

    Yoon, Jihyung; Xie, Yibo; Zhang, Rui

    2018-03-01

    The purpose of this study was to evaluate a methodology to reduce scatter and leakage radiations to patients' surface and shallow depths during conventional and advanced external beam radiotherapy. Superflab boluses of different thicknesses were placed on top of a stack of solid water phantoms, and the bolus effect on surface and shallow depth doses for both open and intensity-modulated radiotherapy (IMRT) beams was evaluated using thermoluminescent dosimeters and ion chamber measurements. Contralateral breast dose reduction caused by the bolus was evaluated by delivering clinical postmastectomy radiotherapy (PMRT) plans to an anthropomorphic phantom. For the solid water phantom measurements, surface dose reduction caused by the Superflab bolus was achieved only in out-of-field area and on the incident side of the beam, and the dose reduction increased with bolus thickness. The dose reduction caused by the bolus was more significant at closer distances from the beam. Most of the dose reductions occurred in the first 2-cm depth and stopped at 4-cm depth. For clinical PMRT treatment plans, surface dose reductions using a 1-cm Superflab bolus were up to 31% and 62% for volumetric-modulated arc therapy and 4-field IMRT, respectively, but there was no dose reduction for Tomotherapy. A Superflab bolus can be used to reduce surface and shallow depth doses during external beam radiotherapy when it is placed out of the beam and on the incident side of the beam. Although we only validated this dose reduction strategy for PMRT treatments, it is applicable to any external beam radiotherapy and can potentially reduce patients' risk of developing radiation-induced side effects. © 2018 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  11. A criterion-based audit of the technical quality of external beam radiotherapy for prostate cancer

    International Nuclear Information System (INIS)

    Brundage, Michael; Danielson, Brita; Pearcey, Robert; Bass, Brenda; Pickles, Tom; Bahary, Jean-Paul; Peng, Yingwei; Wallace, David; Mackillop, William

    2013-01-01

    Purpose: To evaluate the technical quality of external beam radiotherapy for prostate cancer in Canada. Methods: This was a multi-institution, retrospective study of a random sample of patients undergoing radiotherapy (RT) for prostate cancer in Canada. Patterns of care were determined by abstracting details of the patients’ management from original records. The quality of patient’s technical care was measured against a previously published, comprehensive suite of quality indicators. Results: 32 of the 37 RT centres participated. The total study population of 810 patients included 25% low-risk, 44% intermediate-risk, and 28% high-risk cases. 649 received external beam RT (EBRT) only, for whom compliance with 12 indicators of the quality of pre-treatment assessment ranged from 56% (sexual function documented) to 96% (staging bone scan obtained in high-risk patients). Compliance with treatment-related indicators ranged from 78% (dose to prostate ⩾74 Gy in intermediate risk patients not receiving hormone therapy) to 100% (3DCRT or IMRT plan). Compliance varied among centres; no centre demonstrated 100% compliance on all indicators and every centre was 100% compliant on at least some indicators. The number of assessment-related indicators (n = 13) with which a given centre was 100% compliant ranged from 4 to 11 (median 7) and the number of the treatment-specific indicators (n = 8) with which a given centre was 100% compliant ranged from 6 to 8 (median 8). ADT therapy was utilised in most high-risk cases (191, 92.3%). Conclusions: While patterns of prostate cancer care in Canada vary somewhat, compliance on the majority of quality indicators is very high. However, all centres showed room for improvement on several indicators and few individual patients received care that met target benchmarks on all quality measures. This variation is particularly important for indicators such as delivered dose where impact on disease outcome is known to exist, and suggests that

  12. The Outcome of Conventional External Beam Radiotherapy for Patients with Squamous Cell Carcinoma of the Esophagus

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Ji Young [Chosun University College of Medicine, Gwangju (Korea, Republic of)

    2008-03-15

    The best treatment for advanced esophageal cancer is chemoradiotherapy followed by surgery. In spite of the advance of multimodality therapy, most patients with esophageal cancer are treated with radiation therapy alone. This study reports the outcome of the use of conventional external beam radiotherapy alone for the treatment of esophageal cancer. Between January 1998 and December 2005, 30 patients with squamous cell carcinoma of the esophagus were treated with external beam radiotherapy using a total dose exceeding 40 Gy. Radiotherapy was delivered with a total dose of 44-60 Gy (median dose, 57.2 Gy) over 36 {approx}115 days (median time, 45 days). Thirteen patients (43.3%) had a history of disorders such as diabetes, hypertension, tuberculosis, lye stricture, asthma, cerebral infarct, and cancers. Four patients metachronously had double primary cancers. The most common location of a tumor was the mid-thoracic portion of the esophagus (56.7%). Tumor lengths ranged from 2 cm to 11 cm, with a median length of 6 cm. For AJCC staging, stage III was the most common (63.3%). Five patients had metastases at diagnosis. The median overall survival was 8.3 months. The survival rates at 1-year and 2-years were 33.3% and 18.7%, respectively. The complete response rate 1{approx}3 months after radiotherapy was 20% (6/30) and the partial response rate was 70% (21/30). Sixteen patients (53.3%) had an improved symptom of dysphagia. Significant prognostic factors were age, tumor length, stage, degree of dysphagia at the time of diagnosis and tumor response. Cox regression analysis revealed the aim of treatment, clinical tumor response and tumor length as independent prognostic factors for overall survival. Twenty-eight patients had local failure and another four patients had metastases. Three patients were detected with double primary cancers in this analysis. A complication of esophageal stricture was observed in three patients (10%), and radiation pneumonitis occurred in two

  13. The Outcome of Conventional External Beam Radiotherapy for Patients with Squamous Cell Carcinoma of the Esophagus

    International Nuclear Information System (INIS)

    Jang, Ji Young

    2008-01-01

    The best treatment for advanced esophageal cancer is chemoradiotherapy followed by surgery. In spite of the advance of multimodality therapy, most patients with esophageal cancer are treated with radiation therapy alone. This study reports the outcome of the use of conventional external beam radiotherapy alone for the treatment of esophageal cancer. Between January 1998 and December 2005, 30 patients with squamous cell carcinoma of the esophagus were treated with external beam radiotherapy using a total dose exceeding 40 Gy. Radiotherapy was delivered with a total dose of 44-60 Gy (median dose, 57.2 Gy) over 36 ∼115 days (median time, 45 days). Thirteen patients (43.3%) had a history of disorders such as diabetes, hypertension, tuberculosis, lye stricture, asthma, cerebral infarct, and cancers. Four patients metachronously had double primary cancers. The most common location of a tumor was the mid-thoracic portion of the esophagus (56.7%). Tumor lengths ranged from 2 cm to 11 cm, with a median length of 6 cm. For AJCC staging, stage III was the most common (63.3%). Five patients had metastases at diagnosis. The median overall survival was 8.3 months. The survival rates at 1-year and 2-years were 33.3% and 18.7%, respectively. The complete response rate 1∼3 months after radiotherapy was 20% (6/30) and the partial response rate was 70% (21/30). Sixteen patients (53.3%) had an improved symptom of dysphagia. Significant prognostic factors were age, tumor length, stage, degree of dysphagia at the time of diagnosis and tumor response. Cox regression analysis revealed the aim of treatment, clinical tumor response and tumor length as independent prognostic factors for overall survival. Twenty-eight patients had local failure and another four patients had metastases. Three patients were detected with double primary cancers in this analysis. A complication of esophageal stricture was observed in three patients (10%), and radiation pneumonitis occurred in two patients (6

  14. Urinary incontinence in prostate cancer patients treated with external beam radiotherapy

    International Nuclear Information System (INIS)

    Liu, Mitchell; Pickles, Tom; Berthelet, Eric; Agranovich, Alexander; Kwan, Winkle; Tyldesley, Scott; McKenzie, Michael; Keyes, Mira; Morris, James; Pai, Howard

    2005-01-01

    Background and purpose: To describe the incidence of urinary incontinence among prostate cancer patients treated with external beam radiotherapy (RT) and to investigate associated risk factors. Patients and methods: One thousand and hundred ninety-two patients with ≥24 months follow-up were the subjects of this series. All patients received between 50 and 72 Gy in 20-37 fractions (median 66 Gy/33). Post-RT urinary incontinence was scored by direct patient interviewing according to the modified RTOG/SOMA scale: Grade 1-occasional use of incontinence pads, Grade 2-intermittent use of incontinence pads, Grade 3-persistent use of incontinence pads, and Grade 4-permanent catheter. Risk-factors investigated were: age, diabetes, TURP prior to RT, elapsed time from TURP to RT, clinical stage, RT dose and presence of Grade ≥2 acute GU and GI toxicity. Non-parametric, actuarial univariate (Kaplan-Meier) and multivariate tests (MVA, Cox regression) were performed. Results: Median follow-up for the group is 52 months (24-109). Thirty-four patients (2.9%) had incontinence prior to RT, which was more common in TURP patients (7.8% vs 1.6% P<0.001). These are excluded from further analysis. Fifty-seven patients (4.9%) developed Grade 1 incontinence, 7 (0.6%) Grade 2, and 7 (0.6%) Grade 3. There was no Grade 4 incontinence. Actuarial rates for Grade ≥1 and ≥2 incontinence at 5 years are 7 and 1.7%, respectively. Risk factors on MVA associated with the development of Grade 1 or worse incontinence are pre-RT TURP (5-year rates 10% vs 6%, P=0.026), presence of Grade ≥2 acute GU toxicity (5-year rates 11% vs 5%, P=0.002). Age, diabetes, clinical stage, elapsed time from TURP to RT, RT dose or fraction size, acute GI toxicity were not significant. Patients who underwent post-RT TURP or dilatation for obstructive symptoms (4.3%), were more likely to develop Grade 2-3 incontinence (5-year rate 8 vs 1.5%, P=0.0015). Conclusions: Grade 2 or greater urinary incontinence is rare

  15. Locally advanced prostatic cancer: experience with combined pelvic external beam irradiation and interstitial thermobrachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, Steven L; Kapp, Daniel S; Goffinet, Don R; Prionas, Stavros; Cox, Richard S; Bagshaw, Malcolm A

    1995-07-01

    Purpose: Recurrence of prostatic carcinoma within the prostate gland remains a significant problem for patients who present with locally advanced disease. In an attempt to improve the local control of such tumors, an iridium-192 transperineal, template-guided prostatic implant was combined wit radiofrequency-induced hyperthermia after external beam irradiation of the pelvic lymph nodes and prostate gland. This study evaluates the influence of pre-treatment patient characteristics and treatment parameters upon outcome. Materials and Methods: Between July 1987 and April 1992 33 patients with adenocarcinoma of the prostate were selected for treatment: 28 of these patients had extensive local disease on clinical examination (AJCC-4 stages T2b or c: 9 patients; T3: 19 patients); two patients with T2a tumors had Gleason grade 5 + 4 disease or disproportionately high prostate specific antigen (PSA) values and a mass encroaching upon the bladder on computerized tomographic scan. Three patients with more clinically limited T2a or T2b involvement elected implantation in lieu of an external beam irradiation boost. The mean pre-treatment serum PSA value was 25.6 ng/ml (Hybritech scale), with values of above 19 ng/ml for 17 of the patients. Treatment consisted of 50 Gy of external beam irradiation to the prostate and pelvic lymph nodes followed by a transperineal needle implant of the prostate gland. Thirty-two patients had no evidence of pelvic nodal involvement during exploration at laparotomy performed after external irradiation, and 25 of these had lymph node samplings that were histologically negative for metastasis. Perineal template oriented needles were placed by inspection and palpation at laparotomy; 2 were performed closed under ultrasound guidance. Needles were afterloaded with {sup 192}Ir to provide a dose of 30 Gy to the periphery of the prostate gland. Interstitial radiofrequency-induced hyperthermia treatments were given in conjunction with the implant, one just

  16. Improving efficiency and safety in external beam radiation therapy treatment delivery using a Kaizen approach.

    Science.gov (United States)

    Kapur, Ajay; Adair, Nilda; O'Brien, Mildred; Naparstek, Nikoleta; Cangelosi, Thomas; Zuvic, Petrina; Joseph, Sherin; Meier, Jason; Bloom, Beatrice; Potters, Louis

    Modern external beam radiation therapy treatment delivery processes potentially increase the number of tasks to be performed by therapists and thus opportunities for errors, yet the need to treat a large number of patients daily requires a balanced allocation of time per treatment slot. The goal of this work was to streamline the underlying workflow in such time-interval constrained processes to enhance both execution efficiency and active safety surveillance using a Kaizen approach. A Kaizen project was initiated by mapping the workflow within each treatment slot for 3 Varian TrueBeam linear accelerators. More than 90 steps were identified, and average execution times for each were measured. The time-consuming steps were stratified into a 2 × 2 matrix arranged by potential workflow improvement versus the level of corrective effort required. A work plan was created to launch initiatives with high potential for workflow improvement but modest effort to implement. Time spent on safety surveillance and average durations of treatment slots were used to assess corresponding workflow improvements. Three initiatives were implemented to mitigate unnecessary therapist motion, overprocessing of data, and wait time for data transfer defects, respectively. A fourth initiative was implemented to make the division of labor by treating therapists as well as peer review more explicit. The average duration of treatment slots reduced by 6.7% in the 9 months following implementation of the initiatives (P = .001). A reduction of 21% in duration of treatment slots was observed on 1 of the machines (P Kaizen approach has the potential to improve operational efficiency and safety with quick turnaround in radiation therapy practice by addressing non-value-adding steps characteristic of individual department workflows. Higher effort opportunities are identified to guide continual downstream quality improvements. Copyright © 2017 American Society for Radiation Oncology. Published by

  17. Peripheral photon and neutron doses from prostate cancer external beam irradiation.

    Science.gov (United States)

    Bezak, Eva; Takam, Rundgham; Marcu, Loredana G

    2015-12-01

    Peripheral photon and neutron doses from external beam radiotherapy (EBRT) are associated with increased risk of carcinogenesis in the out-of-field organs; thus, dose estimations of secondary radiation are imperative. Peripheral photon and neutron doses from EBRT of prostate carcinoma were measured in Rando phantom. (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P glass-rod thermoluminescence dosemeters (TLDs) were inserted in slices of a Rando phantom followed by exposure to 80 Gy with 18-MV photon four-field 3D-CRT technique. The TLDs were calibrated using 6- and 18-MV X-ray beam. Neutron dose equivalents measured with CR-39 etch-track detectors were used to derive readout-to-neutron dose conversion factor for (6)LiF:Mg,Cu,P TLDs. Average neutron dose equivalents per 1 Gy of isocentre dose were 3.8±0.9 mSv Gy(-1) for thyroid and 7.0±5.4 mSv Gy(-1) for colon. For photons, the average dose equivalents per 1 Gy of isocentre dose were 0.2±0.1 mSv Gy(-1) for thyroid and 8.1±9.7 mSv Gy(-1) for colon. Paired (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P TLDs can be used to measure photon and neutron doses simultaneously. Organs in close proximity to target received larger doses from photons than those from neutrons whereas distally located organs received higher neutron versus photon dose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Salvage external beam radiotherapy for clinical failure after cryosurgery for prostate cancer

    International Nuclear Information System (INIS)

    McDonough, Michael J.; Feldmeier, John J.; Parsai, Ishmael; Dobelbower, Ralph R.; Selman, Steven H.

    2001-01-01

    Purpose: To investigate the role of external beam radiotherapy (EBRT) as salvage treatment of prostate cancer after cryosurgery failure. Methods and Materials: Between 1993 and 1998, 6 patients underwent EBRT with curative intent for local recurrence of prostate cancer after cryosurgery. All 6 patients had biopsy-proven recurrence and palpable disease on digital rectal examination at the time of EBRT. The median follow-up was 34 months (range 8-46). The median prostate-specific antigen level was 2.3 ng/mL (range 0.8-4.1). No patient had evidence of metastatic disease. Two patients received hormonal therapy before beginning EBRT. No patient received hormonal therapy after EBRT completion. The median elapsed time between cryosurgery and EBRT was 3 years (range 1.5-4). The median delivered dose was 66 Gy (range 62-70.2) using a 10-MeV photon beam. An in-house-developed three-dimensional treatment planning system was used to plan delivery of the prescribed dose with conformal radiotherapy techniques. Results: After EBRT, all patients had complete resolution of palpable disease. Four patients (66%) were disease free at the time of the last follow-up. Two patients developed biochemical failure as defined by the American Society for Therapeutic Radiology and Oncology consensus definition. One of these patients had a prostate-specific antigen level of 97 ng/mL before cryosurgery. No patient developed distant metastasis during follow-up. Two patients (33%) developed proctitis; 1 case resolved with Rowasa suppositories and 1 required blood transfusion. Conclusions: Our preliminary results suggest that EBRT can render a significant number of patients biochemically free of disease and can cause complete resolution of clinically palpable disease after initial cryosurgery. The results also showed that EBRT can be given without excessive morbidity. EBRT should be considered as a treatment option in these potentially curable cases

  19. Radiation safety assessment of cobalt 60 external beam radiotherapy using the risk-matrix method

    International Nuclear Information System (INIS)

    Dumenigo, C; Vilaragut, J.J.; Ferro, R.; Guillen, A.; Ramirez, M.L.; Ortiz Lopez, P.; Rodriguez, M.; McDonnell, J.D.; Papadopulos, S.; Pereira, P.P.; Goncalvez, M.; Morales, J.; Larrinaga, E.; Lopez Morones, R.; Sanchez, R.; Delgado, J.M.; Sanchez, C.; Somoano, F.

    2008-01-01

    External beam radiotherapy is the only practice in which humans are placed directly in a radiation beam with the intention to deliver a very high dose. This is why safety in radiotherapy is very critical, and is a matter of interest to both radiotherapy departments and regulatory bodies. Accidental exposures have occurred throughout the world, thus showing the need for systematic safety assessments, capable to identify preventive measures and to minimize consequences of accidental exposure. Risk-matrix is a systematic approach which combines the relevant event features to assess the overall risk of each particular event. Once an event sequence is identified, questions such as how frequent the event, how severe the potential consequences and how reliable the existing safety measures are answered in a risk-matrix table. The ultimate goal is to achieve that the overall risk for events with severe consequences should always be low o very low. In the present study, the risk-matrix method has been applied to an hypothetical radiotherapy department, which could be equivalent to an upper level hospital of the Ibero American region, in terms of safety checks and preventive measures. The application of the method has identified 76 event sequences and revealed that the hypothetical radiotherapy department is sufficiently protected (low risk) against them, including 23 event sequences with severe consequences. The method has revealed that the risk of these sequences could grow to high level if certain specific preventive measures were degraded with time. This study has identified these preventive measures, thus facilitating a rational allocation of resources in regular controls to detect any loss of reliability. The method has proven to have an important practical value and is affordable at hospital level. The elaborated risk-matrix can be easily adapted to local circumstances, in terms of existing controls and safety measures. This approach can help hospitals to identify

  20. Perspectives in absorbed dose metrology with regard to the technical evolutions of external beam radiotherapy

    International Nuclear Information System (INIS)

    Chauvenet, B.; Bordy, J.M.; Barthe, J.

    2009-01-01

    This paper presents several R and D axes in absorbed close metrology to meet the needs resulting from the technical evolutions of external beam radiotherapy. The facilities in operation in France have considerably evolved under the impulse of the plan Cancer launched in 2003: replacements and increase of the number of accelerators, substitution of accelerators for telecobalt almost completed and acquisition of innovative facilities for tomo-therapy and stereotaxy. The increasing versatility of facilities makes possible the rapid evolution of treatment modalities, allowing to better delimit irradiation to tumoral tissues and spare surrounding healthy tissues and organs at risk. This leads to a better treatment efficacy through dose escalation. National metrology laboratories must offer responses adapted to the new need, i.e. not restrict themselves to the establishment of references under conventional conditions defined at international level, contribute to the improvement of uncertainties at all levels of reference transfer to practitioners: primary measurements under conditions as close as possible to those of treatment, characterization of transfer and treatment control dosimeters., metrological validation of treatment planning tools... Those axes have been identified as priorities for the next years in ionizing radiation metrology at the European level and included in the European. Metrology Research Programme. A project dealing with some of those topics has been selected in the frame of the Eranet+ Call EMRP 2007 and is now starting. The LNE-LAM is strongly engaged in it. (authors)

  1. PSA bounces after neoadjuvant androgen deprivation and external beam radiation: Impact on definitions of failure

    International Nuclear Information System (INIS)

    Zietman, Anthony L.; Christodouleas, John P.; Shipley, William U.

    2005-01-01

    Purpose: To determine the characteristics of prostate specific antigen (PSA) bounces after external beam radiation therapy (EBRT) with neoadjuvant androgen deprivation and their impact on definitions of biochemical failure. Methods and Materials: Characteristics of bounce were calculated for all patients treated by EBRT with neoadjuvant androgen deprivation at our institution between 1992 and 1998 (preexclusion analysis). Calculations were repeated for the subgroup that satisfied additional inclusion/exclusion criteria (postexclusion analysis). The percentage of bounces scoring as false positives according to the ASTRO definition of biochemical failure was compared with those for three alternative definitions (Vancouver, Nadir-plus-two, and Nadir-plus-three) using McNemar's tests. Results: Thirty-nine percent (preexclusion cohort) and 56% (postexclusion cohort) of patients demonstrated a PSA bounce. Twenty percent (preexclusion analysis) and 25% (postexclusion analysis) of these bounces scored as biochemical failure according to the ASTRO definition. The Nadir-plus-three definition scored the smallest percentage of bounces as failure, but the difference between this definition and the ASTRO definition reached statistical significance in neither preexclusion nor postexclusion analyses (p ≥ 0.070). Conclusions: A substantial proportion of patients treated by EBRT with neoadjuvant deprivation experienced a PSA bounce. A large percentage of these bounces scored as biochemical failure according to the ASTRO definition. The Nadir-plus-three definition is less vulnerable to this bias

  2. 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.)

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

    International Nuclear Information System (INIS)

    Putora, P.M.; Buchauer, K.; Plasswilm, L.; Engeler, D.; Schmid, H.P.; Haile, S.R.; Graf, N.

    2016-01-01

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

  4. Reducing the risk of radiocarcinogenesis in paediatric patients treated with external beam radiotherapy

    International Nuclear Information System (INIS)

    Taylor, M.L.; Franich, R.D.; Kron, Tomas

    2010-01-01

    Full text: The aim of this study was to determine readily-implementable means of out-of-field dose reduction in paediatric patients undergoing external beam radiotherapy for intracranial lesions. [n this way, the risk of secondary cancer induction may be reduced. Dose measurements were taken using LiF:Mg, Cu, P TLD 1 00 H chips in a 5 year old paediatric phantom. Multiple TLDs were placed at: the right and left lenses of the eye, optic nerve, brain, thyroid, lungs, heart, kidneys, abdomen and gonads. Varian 600 C and Varian Trilogy linear accelerators, both at 6 MV, were investigated, using different delivery parameters. Most of the out-of-field dose at large distances is attributable to leakage. The difference between stereotactic and larger field sizes is less significant far from the primary field. Out-of-field dose from the Trilogy was 40% higher than the 600 e . Aligning the craniocaudal axis of the patient with the x-plane of the collimator results in a dose reduction of 40%, for both machines. - A simple shielding arrangement may halve out-of-field dose. (author)

  5. Hypofractionated Proton Boost Combined with External Beam Radiotherapy for Treatment of Localized Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Silvia Johansson

    2012-01-01

    Full Text Available Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT. The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU and gastrointestinal (GI toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity.

  6. A Preliminary Design Of Application Of Wireless Identification And Sensing Platform On External Beam Radiotherapy

    Science.gov (United States)

    Heranudin; Bakhri, S.

    2018-02-01

    A linear accelerator (linac) is widely used as a means of radiotherapy by focusing high-energy photons in the targeted tumor of patient. Incorrectness of the shooting can lead normal tissue surrounding the tumor received unnecessary radiation and become damaged cells. A method is required to minimize the incorrectness that mostly caused by movement of the patient during radiotherapy process. In this paper, the Wireless Identification and Sensing Platform (WISP) architecture was employed to monitor in real time the movement of the patient’s body during radiotherapy process. In general, the WISP is a wearable sensors device that can transmit measurement data wirelessly. In this design, the measurement devices consist of an accelerometer, a barometer and an ionizing radiation sensor. If any changes in the body position which resulted in incorrectness of the shooting, the accelerometer and the barometer will trigger a warning to the linac operator. In addition, the radiation sensor in the WISP will detect unwanted radiation and that can endanger the patient. A wireless feature in this device can ease in implementation. Initial analyses have been performed and showed that the WISP is feasible to be applied on external beam radiotherapy.

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

    International Nuclear Information System (INIS)

    Aubry, Jean-Francois; Beaulieu, Frederic; Sevigny, Caroline; Beaulieu, Luc; Tremblay, Daniel

    2006-01-01

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

  8. Megavoltage external beam irradiation of craniopharyngiomas: Analysis of tumor control and morbidity

    International Nuclear Information System (INIS)

    Flickinger, J.C.; Lunsford, L.D.; Singer, J.; Cano, E.R.; Deutsch, M.

    1990-01-01

    From 1971 to 1985, 21 patients received megavoltage external beam radiation therapy at the University of Pittsburgh for control of craniopharyngioma. Minimum tumor doses prescribed to the 95% isodose volume ranged between 51.3 to 70.0 Gy. Median total dose was 60.00 Gy and median dose per fraction was 1.83 Gy. Three deaths occurred from intercurrent disease and no deaths from tumor progression. Actuarial overall survival was 89% and 82% at 5 and 10 years. Actuarial local control was 95% at 5 and 10 years. Radiation related complications included one patient with optic neuropathy, one with brain necrosis, and one that developed optic neuropathy followed by brain necrosis. The high dose group of patients who received a NSD or Neuret equivalent of greater than 60 Gy at 1.8 Gy per fraction had a significantly greater risk of radiation complications (p = .024). The actuarial risk at 5 years for optic neuropathy was 30% and brain necrosis was 12.5% in the high dose group. Tumor control in the high dose group was not shown to be significantly better. Any possible benefit in tumor control in treating patients with craniopharyngioma with doses above 60 Gy at 1.8 Gy per fraction appears to be offset by the increased risk of radiation injury

  9. Risk of Fatal Cerebrovascular Accidents after External Beam Radiation Therapy for Early Stage Glottic Larynx Cancer

    Science.gov (United States)

    Swisher-McClure, Samuel; Mitra, Nandita; Lin, Alexander; Ahn, Peter; Wan, Fei; O’Malley, Bert; Weinstein, Gregory S.; Bekelman, Justin E.

    2013-01-01

    Background This study compared the risk of fatal cerebrovascular accidents (CVA) in patients with early stage glottic larynx cancer receiving surgery or external beam radiation therapy (EBRT). Methods and Materials Using a competing risks survival analysis, we compared the risk of death due to CVA among patients with early stage glottic larynx cancer receiving surgery or EBRT in the SEER database. Results The cumulative incidence of fatal CVA at 15 years was higher in patients receiving EBRT (2.8 %; 95% CI 2.3%–3.4%) compared to surgery (1.5 %; 95% CI 0.8 %–2.3%, p= 0.024). In multivariable competing risks regression models, EBRT remained associated with an increased risk of fatal CVA compared to surgery (adjusted HR 1.75; 95% CI 1.04–2.96, p= 0.037). Conclusion Treatment of early stage glottic larynx cancer with EBRT was associated with a small increase in the risk of late fatal CVA events relative to surgery. PMID:23595858

  10. Sexual function after external-beam radiotherapy for prostate cancer: what do we know?

    Science.gov (United States)

    Incrocci, Luca

    2006-02-01

    Quality of life in general and sexual functioning in particular have become very important in cancer patients. Due to modern surgical techniques, improved quality of drugs for chemotherapy and very modern radiation techniques, more patients can be successfully treated without largely compromising sexual functioning. One can assume that because of the life-threatening nature of cancer, sexual activity is not important to patients and their partners, but this is not true. Prostate cancer has become the most common non-skin malignant neoplasm in older men in Western countries. In this paper, we discuss the various methods used to evaluate erectile and sexual dysfunction and the definition of potency. Data on the etiology of erectile dysfunction after external-beam radiotherapy for prostate cancer is reviewed, and the literature is been summarized. Patients should be offered sexual counseling and informed about the availability of effective treatments for erectile dysfunction, such as sildenafil, intracavernosal injection, and vacuum devices. Cancer affects quality of life and sexual function. The challenge for oncologists is to address this with compassion.

  11. Future of external beam irradiation as initial treatment of rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Papillon, J.

    1987-06-01

    The authors' protocol consists of a split-course regimen with a short course of cobalt-60 arc rotation (3000 c/Gy in 12 days). After 2 months rest, the second stage treatment depends upon the pressure of residual disease and the tumour site. It consists of either radical surgery (82 cases) or conservative treatment by intracavitary irradiation in the event of a favourable initial response or in the case of poor risk patients (73 cases). In the radiotherapy-surgical group, the subsequent operative specimens were tumour free in 17% of cases and assigned to Dukes' A category in 32% of cases. Of 91 patients with T/sub 2/ or T/sub 3/ tumour involving the lower third of the rectum (followed up for more than 3 years) 72(84%) had no recurrence. Thirty-three of these patients (46%) underwent a colostomy while 39 (54%) has normal anal function. These results demonstrate the major place that a properly planned external beam irradiation can have in the curative management of cancers of the low rectum.

  12. Hypofractionated Proton Boost Combined with External Beam Radiotherapy for Treatment of Localized Prostate Cancer

    Science.gov (United States)

    Johansson, Silvia; Åström, Lennart; Sandin, Fredrik; Isacsson, Ulf; Montelius, Anders; Turesson, Ingela

    2012-01-01

    Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT) of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT). The medium followup was 57 months. The 5-year PSA progression-free survival was 100%, 95%, and 74% for low-, intermediate-, and high-risk patients, respectively. The toxicity evaluation was supported by a patient-reported questionnaire before every consultant visit. Cumulative probability and actuarial prevalence of genitourinary (GU) and gastrointestinal (GI) toxicities are presented according to the RTOG classification. N-ADT did not influence curability. Mild pretreatment GU-symptoms were found to be a strong predictive factor for GU-toxicity attributable to treatment. The actuarial prevalence declined over 3 to 5 years for both GU and GI toxicities, indicating slow resolution of epithelial damage to the genitourinary and gastrointestinal tract. Bladder toxicities rather than gastrointestinal toxicities seem to be dose limiting. More than 5-year followup is necessary to reveal any sign of true progressive late side effects of the given treatment. Hypofractionated proton-boost combined with EBRT is associated with excellent curability of localized PC and acceptable frequencies of treatment toxicity. PMID:22848840

  13. Preirradiation PSA predicts biochemical disease-free survival in patients treated with postprostatectomy external beam irradiation

    International Nuclear Information System (INIS)

    Crane, Christopher H.; Rich, Tyvin A.; Read, Paul W.; Sanfilippo, Nicholas J.; Gillenwater, Jay Y.; Kelly, Maria D.

    1997-01-01

    Purpose: To assess the clinical outcome and prostate-specific antigen (PSA) response and to determine prognostic factors for biochemical disease-free survival in patients treated with external beam radiotherapy following radical prostatectomy without hormonal therapy. Methods and Materials: Forty-eight patients were treated after prostatectomy with radiotherapy between March, 1988 and December, 1993. Seven patients had undetectable PSA ( 2.7. Five-year actuarial biochemical disease-free survival values were 71, 48, and 0%, respectively, for the three groups. Biochemical disease-free survival was not affected by preoperative PSA level, clinical stage, Gleason's score, pathologic stage, surgical margins, presence of undetectable PSA after surgery, surgery to radiation interval, total dose, or presence of clinically suspicious local disease. Based on digital rectal exam, there were no local failures. Conclusion: Biochemical disease-free survival after postprostatectomy radiation is predicted by the PSA at the time of irradiation. Clinical local control is excellent, but distant failure remains a significant problem in this population. The addition of concomitant systemic therapy should be investigated in patients with PSA >2.7

  14. Gas in the rectum tends to reduce during radical external beam radiotherapy for localised prostate cancer

    International Nuclear Information System (INIS)

    Nakamura, Naoki; Mizuno, Norifumo; Endo, Haruna; Ogita, Mami; Kawamori, Jiro; Sekigucho, Kenji; Hatanaka, Shogo; Takahashi, Osamu; Tamaki, Seiichi; Shikama, Naoto

    2014-01-01

    This study aims to clarify the time-course of gas accumulation in the rectum during treatment as guidance for the management of rectal volumes. We reviewed 2042 sets (35.2 sets per patient) of anteroposterior and right–left mega voltage (MV) images obtained for daily set-up from 58 patients who underwent radical external beam radiotherapy for localised prostate cancer. The patients were instructed to take magnesium oxide tablets during radiotherapy. They were also encouraged to avoid foods that might cause intestinal gas during radiotherapy. Gas accumulation in the rectum was graded into three classes by the same radiation oncologist. If no gas was seen in the rectum, it was classified as grade 0. A small amount of gas was classified as grade 1, whereas a marked amount of gas that required removal was classified as grade 2. Of the 2042 sets of MV images, grades 1 and 2 gas accumulation were seen in 332 (16%) and 156 (8%), respectively. By the trend test, gas accumulation significantly decreased towards the end of treatment (P=0.02 for grade 1 or 2 and P=0.02 for grade 2). On multivariate analysis, we did not identify any significant independent predictors for either baseline gas accumulation or gas reduction. Gas accumulation tended to decrease until the end of treatment. This tendency should be reconfirmed by other institutions.

  15. High-dose external beam irradiation inhibits neointima formation in stented pig coronary arteries

    International Nuclear Information System (INIS)

    Verheye, Stefan; Coussement, Patrick K.; Salame, Mahomed Y.; Fallahi, Payam; Cui Jianhua; Chronos, Nicolas A.F.; King, Spencer B.; Crocker, Ian R.; Robinson, Keith A.

    2001-01-01

    Purpose: To evaluate high-dose external beam irradiation (EBRT) in a pig coronary stent preparation because low and intermediate-dose EBRT failed to show inhibition of neointima formation in stented animal models. Methods and Materials: Thirty-five stents were implanted in the coronary arteries of 17 pigs. Seven pigs were exposed to a single dose of 21 Gy EBRT immediately after stenting. Ten stented, nonirradiated pigs served as controls. After 4 weeks, the study arteries and myocardium were examined by light and scanning electron microscopy. Results: Compared with controls, 21 Gy EBRT resulted in a larger lumen area (7.57±1.67 mm 2 vs. 4.00±1.63 mm 2 , p 2 vs. 3.36±2.26 mm 2 , p<0.001) and a smaller maximal intimal thickness (0.16±0.09 mm vs. 0.68±0.31 mm, p<0.001). Unresorbed intramural hemorrhages and adherent mural thrombi were present in the irradiated vessels, which also showed incomplete re-endothelialization. The irradiated hearts demonstrated diffuse interstitial and perivascular inflammation and fibrosis. Conclusions: EBRT at 21 Gy to the entire heart significantly inhibited neointima formation in stented pig coronary arteries but also resulted in incomplete re-endothelialization, myocardial inflammation, and fibrosis. Improvements in localization and delivery techniques are required to allow clinical implementation of this technique

  16. 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.)

  17. Optimising measles virus-guided radiovirotherapy with external beam radiotherapy and specific checkpoint kinase 1 inhibition

    International Nuclear Information System (INIS)

    Touchefeu, Yann; Khan, Aadil A.; Borst, Gerben; Zaidi, Shane H.; McLaughlin, Martin; Roulstone, Victoria; Mansfield, David; Kyula, Joan; Pencavel, Tim; Karapanagiotou, Eleni M.; Clayton, Jamie; Federspiel, Mark J.; Russell, Steve J.; Garrett, Michelle; Collins, Ian; Harrington, Kevin J.

    2013-01-01

    Background and purpose: We previously reported a therapeutic strategy comprising replication-defective NIS-expressing adenovirus combined with radioiodide, external beam radiotherapy (EBRT) and DNA repair inhibition. We have now evaluated NIS-expressing oncolytic measles virus (MV-NIS) combined with NIS-guided radioiodide, EBRT and specific checkpoint kinase 1 (Chk1) inhibition in head and neck and colorectal models. Materials and methods: Anti-proliferative/cytotoxic effects of individual agents and their combinations were measured by MTS, clonogenic and Western analysis. Viral gene expression was measured by radioisotope uptake and replication by one-step growth curves. Potential synergistic interactions were tested in vitro by Bliss independence analysis and in in vivo therapeutic studies. Results: EBRT and MV-NIS were synergistic in vitro. Furthermore, EBRT increased NIS expression in infected cells. SAR-020106 was synergistic with EBRT, but also with MV-NIS in HN5 cells. MV-NIS mediated 131 I-induced cytotoxicity in HN5 and HCT116 cells and, in the latter, this was enhanced by SAR-020106. In vivo studies confirmed that MV-NIS, EBRT and Chk1 inhibition were effective in HCT116 xenografts. The quadruplet regimen of MV-NIS, virally-directed 131 I, EBRT and SAR-020106 had significant anti-tumour activity in HCT116 xenografts. Conclusion: This study strongly supports translational and clinical research on MV-NIS combined with radiation therapy and radiosensitising agents

  18. Time of Decline in Sexual Function After External Beam Radiotherapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Siglin, Joshua; Kubicek, Gregory J.; Leiby, Benjamin; Valicenti, Richard K.

    2010-01-01

    Purpose: Erectile dysfunction is one of the most concerning toxicities for patients in the treatment of prostate cancer. The inconsistent evaluation of sexual function (SF) and limited follow-up data have necessitated additional study to clarify the rate and timing of erectile dysfunction after external beam radiotherapy (EBRT) for prostate cancer. Methods and Materials: A total of 143 men completed baseline data on SF before treatment and at the subsequent follow-up visits. A total of 1187 validated SF inventories were analyzed from the study participants. Multiple domains of SF (sex drive, erectile function, ejaculatory function, and overall satisfaction) were analyzed for ≤8 years of follow-up. Results: The median follow-up was 4.03 years. The strongest predictor of SF after EBRT was SF before treatment. For all domains of SF, the only statistically significant decrease in function occurred in the first 24 months after EBRT. SF stabilized 2 years after treatment completion, with no statistically significant change in any area of SF >2 years after the end of EBRT. Conclusion: These data suggest that SF does not have a continuous decline after EBRT. Instead, SF decreases maximally within the first 24 months after EBRT, with no significant changes thereafter.

  19. An implantable radiation dosimeter for use in external beam radiation therapy

    International Nuclear Information System (INIS)

    Scarantino, Charles W.; Ruslander, David M.; Rini, Christopher J.; Mann, Gregory G.; Nagle, H. Troy; Black, Robert D.

    2004-01-01

    An implantable radiation dosimeter for use with external beam therapy has been developed and tested both in vitro and in canines. The device uses a MOSFET dosimeter and is polled telemetrically every day during the course of therapy. The device is designed for permanent implantation and also acts as a radiographic fiducial marker. Ten dogs (companion animals) that presented with spontaneous, malignant tumors were enrolled in the study and received an implant in the tumor CTV. Three dogs received an additional implant in collateral normal tissue. Radiation therapy plans were created for the animals and they were treated with roughly 300 cGy daily fractions until completion of the prescribed cumulative dose. The primary endpoints of the study were to record any adverse events due to sensor placement and to monitor any movement away from the point of placement. No adverse events were recorded. Unacceptable device migration was experienced in two subjects and a retention mechanism was developed to prevent movement in the future. Daily dose readings were successfully acquired in all subjects. A rigorous in vitro calibration methodology has been developed to ensure that the implanted devices maintain an accuracy of ±3.5% relative to an ionization chamber standard. The authors believe that an implantable radiation dosimeter is a practical and powerful tool that fosters individualized patient QA on a daily basis

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

    Institute of Scientific and Technical Information of China (English)

    Shinya; Hayashi; Hidekazu; Tanaka; Hiroaki; Hoshi

    2014-01-01

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

  1. In-vivo dosimetric study of carcinoma of uterine cervix with FBX solution in external beam therapy

    International Nuclear Information System (INIS)

    Srinivas, Challapalli; Shenoy, K. Kamalaksh; Dinesh, M.; Savitha, K.S.; Kasturi, Dinesh Pai; Supe, S.S.; Nagesha, Y.N.

    1999-01-01

    To ensure accurate dose delivery to target site in external beam therapy and brachytherapy, various authors have conducted tests to assess the process of manual dose calculations. In vivo dosimetric measurement is one of these methods to verify these calculations. In this study, an attempt has been made to compare the manually calculated dose to dose estimated using a chemical dosimeter (FBX) solution (in-vivo method, using polypropylene vials), on 12 patients of carcinoma of uterine cervix in external beam therapy. Dose measured by FBX vial varies in the range of ± 2 to 6.75%, as compared with manual calculations. These variations seen may be attributed to the location of the vial position in the vagina, with reference to the beam axis (may not be horizontal), off axis position, manual calculation variations and reproducibility of the FBX system etc. FBX dosimetry offers itself as an in-vivo method to estimate the dose delivered to the target site in external beam therapy. (author)

  2. A simple technique for treating age-related macular degeneration with external beam radiotherapy

    International Nuclear Information System (INIS)

    Roos, Daniel E.; Francis, J. Winston; Newnham, W. John

    1999-01-01

    Purpose: To develop a simple external beam photon radiotherapy technique to treat age-related macular degeneration without the need for simulation, planning computed tomography (CT) or computer dosimetry. Methods and Materials: The goal was to enable the treatment to be set up reliably on the treatment machine on Day 1 with the patient supine in a head cast without any prior planning. Using measurements of ocular globe topography from Karlsson et al. (Int J Radiat Oncol Biol Phys 1996; 33: 705-712), we chose a point 1.5 cm behind the anterior surface of the upper eyelid (ASUE) as the isocentre of a half-beam, blocked, 5.0 x 3.0-cm, angled lateral field to treat the involved eye. This would position the isocentre about 0.5 cm behind the posterior surface of the lens, and a little over 1 cm in front of the macula, according to Karlsson et al. The setup requires initial adjustment of the gantry from horizontal (to account for any asymmetry of position of the eyes), then angling 15 deg. posteriorly to avoid the contralateral eye. Finally, the couch is raised to position the isocentre 1.5 cm behind the ASUE. Results: To verify the applicability of the technique, we performed CT and computer dosimetry on the first 11 eyes so treated. Our CT measurements were in good agreement with Karlsson et al. The lens dose was < 5% and the macula was within the 95% isodose curve in each case (6-MV linac). Treatment setup time is approximately 10 min each day. The 11 patients were treated with 5 x 2.00 Gy (2 patients) or 5 x 3.00 Gy (9 patients), and subjective response on follow-up over 1 to 12 months (median 4 months) was comparable to previously reported results, with no significant acute side effects. Conclusion: Our technique is easy to set up and reliably treats the macula, with sparing of the lens and contralateral eye. It enables treatment to commence rapidly and cost-effectively without the need for simulation or CT computer planning

  3. Prostate position late in the course of external beam therapy: patterns and predictors

    International Nuclear Information System (INIS)

    Zellars, Richard C.; Roberson, Peter L.; Strawderman, Myla; Zhang Daowen; Sandler, Howard M.; Haken, Randall K. ten; Osher, David; McLaughlin, P. William

    2000-01-01

    Purpose: To examine prostate and seminal vesicles position late in the course of radiation therapy and to determine the effect and predictive value of the bladder and rectum on prostate and seminal vesicles positioning. Methods and Materials: Twenty-four patients with localized prostate cancer underwent a computerized tomography scan (CT1) before the start of radiation therapy. After 4-5 weeks of radiation therapy, a second CT scan (CT2) was obtained. All patients were scanned in the supine treatment position with instructions to maintain a full bladder. The prostate, seminal vesicles, bladder, and rectum were contoured. CT2 was aligned via fixed bony anatomy to CT1. The geometrical center and volume of each structure were obtained and directly compared. Results: The prostate shifted along a diagonal axis extending from an anterior-superior position to a posterior-inferior position. The dominant shift was to a more posterior-inferior position. On average, bladder and rectal volumes decreased to 51% (no. +-no. 29%) and 82% (no. +-no. 45%) of their pretreatment values, respectively. Multiple regression analysis (MRA) revealed that bladder movement and volume change and upper rectum movement were independently associated with prostate motion (p = 0.016, p = 0.003, and p = 0.052 respectively). Conclusion: Patients are often instructed to maintain a full bladder during a course of external beam radiation therapy, in the hopes of decreasing bladder and small bowel toxicity. However, our study shows that large bladder volumes late in therapy are strongly associated with posterior prostate displacement. This prostate displacement may result in marginal miss

  4. Variation in Adherence to External Beam Radiotherapy Quality Measures Among Elderly Men With Localized Prostate Cancer

    International Nuclear Information System (INIS)

    Bekelman, Justin E.; Zelefsky, Michael J.; Jang, Thomas L.; Basch, Ethan M.; Schrag, Deborah

    2007-01-01

    Purpose: To characterize the variation in adherence to quality measures of external beam radiotherapy (EBRT) for localized prostate cancer and its relation to patient and provider characteristics in a population-based, representative sample of U.S. men. Methods and Materials: We evaluated EBRT quality measures proposed by a RAND expert panel of physicians among men aged ≥65 years diagnosed between 2000 and 2002 with localized prostate cancer and treated with primary EBRT using data from the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare program. We assessed the adherence to five EBRT quality measures that were amenable to analysis using SEER-Medicare data: (1) use of conformal RT planning; (2) use of high-energy (>10-MV) photons; (3) use of custom immobilization; (4) completion of two follow-up visits with a radiation oncologist in the year after therapy; and (5) radiation oncologist board certification. Results: Of the 11,674 patients, 85% had received conformal RT planning, 75% had received high-energy photons, and 97% had received custom immobilization. One-third of patients had completed two follow-up visits with a radiation oncologist, although 91% had at least one visit with a urologist or radiation oncologist. Most patients (85%) had been treated by a board-certified radiation oncologist. Conclusions: The overall high adherence to EBRT quality measures masked substantial variation in geography, socioeconomic status in the area of residence, and teaching affiliation of the RT facility. Future research should examine the reasons for the variations in these measures and whether the variation is associated with important clinical outcomes

  5. Safety and Efficacy of Thoracic External Beam Radiotherapy After Airway Stenting in Malignant Airway Obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Rochet, Nathalie, E-mail: nrochet@partners.org [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Hauswald, Henrik; Schmaus, Martina; Hensley, Frank [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany); Huber, Peter [Department of Radiotherapy, German Cancer Research Center, Heidelberg (Germany); Eberhardt, Ralf; Herth, Felix J. [Department of Pulmonology and Respiratory Care Medicine, Thoraxklinik at University of Heidelberg, Heidelberg (Germany); Debus, Juergen; Neuhof, Dirk [Department of Radiation Oncology, University of Heidelberg, Heidelberg (Germany)

    2012-05-01

    Purpose: We retrospectively evaluated the outcome and toxicity of external beam radiotherapy (EBRT) after airway stents were placed in patients treated for malignant airway obstruction. Methods and Materials: Between 2004 and 2009, we performed airway stenting followed by EBRT in 43 patients for symptomatic primary lung cancer (n = 31) or other thoracic malignancies (n = 12). The median time interval between stent placement and first irradiation was 14 days. A median total dose of 50 Gy was delivered. Sixty-seven percent of the patients had reduced performance status (Karnofsky performance score, {<=}70). Results: EBRT had to be stopped prematurely in 16 patients (37%), at a median total dose of 17 Gy, for various reasons. In this group of patients, the survival was poor, with a median overall survival (OS) of only 21 days. Twenty-seven patients (63%) completed radiotherapy as planned, with a median OS of 8.4 months. Fourteen of 43 patients (33%) developed at least one Common Terminology Criteria for Adverse Event of grade 3 to 5. The most common event was a malignant restenosis of the stent leading to asphyxia (n = 7), followed by fistula formation (n = 4), necrosis (n = 3), mediastinitis with abscess (n = 1), secondary nonmalignant airway stenosis (n = 1), and hemoptysis (n = 1). With the exception of one event, all events were associated with a local progression of the tumor. Conclusions: Although the long-term prognosis for patients with malignant airway obstruction is poor, airway stenting combined with EBRT offers a possible therapeutic option, achieving fast relief of acute respiratory distress with an associated antitumor effect, resulting in a potential survival benefit. However, due to local advanced tumor growth, increased rates of adverse events are to be expected, necessitating careful monitoring.

  6. Safety and Efficacy of Thoracic External Beam Radiotherapy After Airway Stenting in Malignant Airway Obstruction

    International Nuclear Information System (INIS)

    Rochet, Nathalie; Hauswald, Henrik; Schmaus, Martina; Hensley, Frank; Huber, Peter; Eberhardt, Ralf; Herth, Felix J.; Debus, Juergen; Neuhof, Dirk

    2012-01-01

    Purpose: We retrospectively evaluated the outcome and toxicity of external beam radiotherapy (EBRT) after airway stents were placed in patients treated for malignant airway obstruction. Methods and Materials: Between 2004 and 2009, we performed airway stenting followed by EBRT in 43 patients for symptomatic primary lung cancer (n = 31) or other thoracic malignancies (n = 12). The median time interval between stent placement and first irradiation was 14 days. A median total dose of 50 Gy was delivered. Sixty-seven percent of the patients had reduced performance status (Karnofsky performance score, ≤70). Results: EBRT had to be stopped prematurely in 16 patients (37%), at a median total dose of 17 Gy, for various reasons. In this group of patients, the survival was poor, with a median overall survival (OS) of only 21 days. Twenty-seven patients (63%) completed radiotherapy as planned, with a median OS of 8.4 months. Fourteen of 43 patients (33%) developed at least one Common Terminology Criteria for Adverse Event of grade 3 to 5. The most common event was a malignant restenosis of the stent leading to asphyxia (n = 7), followed by fistula formation (n = 4), necrosis (n = 3), mediastinitis with abscess (n = 1), secondary nonmalignant airway stenosis (n = 1), and hemoptysis (n = 1). With the exception of one event, all events were associated with a local progression of the tumor. Conclusions: Although the long-term prognosis for patients with malignant airway obstruction is poor, airway stenting combined with EBRT offers a possible therapeutic option, achieving fast relief of acute respiratory distress with an associated antitumor effect, resulting in a potential survival benefit. However, due to local advanced tumor growth, increased rates of adverse events are to be expected, necessitating careful monitoring.

  7. Comparative Study of Inguinal Hernia Repair Rates After Radical Prostatectomy or External Beam Radiotherapy

    International Nuclear Information System (INIS)

    Lughezzani, Giovanni; Sun, Maxine; Perrotte, Paul; Alasker, Ahmed; Jeldres, Claudio; Isbarn, Hendrik; Budaeus, Lars; Lattouf, Jean-Baptiste; Valiquette, Luc; Benard, Francois; Saad, Fred; Graefen, Markus; Montorsi, Francesco; Karakiewicz, Pierre I.

    2010-01-01

    Purpose: We tested the hypothesis that patients treated for localized prostate cancer with radical prostatectomy (RP) have a higher risk of requiring an inguinal hernia (IH) repair than their counterparts treated with external beam radiotherapy (EBRT). Methods and Materials: Within the Quebec Health Plan database, we identified 6,422 men treated with RP and 4,685 men treated with EBRT for localized prostate cancer between 1990 and 2000, in addition to 6,933 control patients who underwent a prostate biopsy. From among that population, we identified patients who underwent a unilateral or bilateral hernia repair after either RP or EBRT. Kaplan-Meier plots showed IH repair-free survival rates. Univariable and multivariable Cox regression models tested the predictors of IH repair after RP or EBRT. Covariates consisted of age, year of surgery, and Charlson Comorbidity Index. Results: IH repair-free survival rates at 1, 2, 5, and 10 years were 96.8, 94.3, 90.5, and 86.2% vs. 98.9, 98.0, 95.4, and 92.2%, respectively, in RP vs. EBRT patients (log-rank test, p < 0.001). IH repair-free survival rates in the biopsy population were 98.3, 97.1, 94.9, and 90.2% at the same four time points. In multivariable Cox regression models, RP predisposed to a 2.3-fold higher risk of IH repair than EBRT (p < 0.001). Besides therapy type, patient age (p < 0.001) represented the only other independent predictor of IH repair. Conclusions: RP predisposes to a higher rate of IH repair relative to EBRT. This observation should be considered at informed consent.

  8. Hormonal changes after localized prostate cancer treatment. Comparison between external beam radiation therapy and radical prostatectomy.

    Science.gov (United States)

    Planas, J; Celma, A; Placer, J; Maldonado, X; Trilla, E; Salvador, C; Lorente, D; Regis, L; Cuadras, M; Carles, J; Morote, J

    2016-11-01

    To determine the influence of radical prostatectomy (RP) and external beam radiation therapy (EBRT) on the hypothalamic pituitary axis of 120 men with clinically localized prostate cancer treated with RP or EBRT exclusively. 120 patients with localized prostate cancer were enrolled. Ninety two patients underwent RP and 28 patients EBRT exclusively. We measured serum levels of luteinizing hormone, follicle stimulating hormone (FSH), total testosterone (T), free testosterone, and estradiol at baseline and at 3 and 12 months after treatment completion. Patients undergoing RP were younger and presented a higher prostate volume (64.3 vs. 71.1 years, p<0.0001 and 55.1 vs. 36.5 g, p<0.0001; respectively). No differences regarding serum hormonal levels were found at baseline. Luteinizing hormone and FSH levels were significantly higher in those patients treated with EBRT at three months (luteinizing hormone 8,54 vs. 4,76 U/l, FSH 22,96 vs. 8,18 U/l, p<0,0001) while T and free testosterone levels were significantly lower (T 360,3 vs. 414,83ng/dl, p 0,039; free testosterone 5,94 vs. 7,5pg/ml, p 0,018). At 12 months FSH levels remained significantly higher in patients treated with EBRT compared to patients treated with RP (21,01 vs. 8,51 U/l, p<0,001) while T levels remained significantly lower (339,89 vs. 402,39ng/dl, p 0,03). Prostate cancer treatment influences the hypothalamic pituitary axis. This influence seems to be more important when patients with prostate cancer are treated with EBRT rather than RP. More studies are needed to elucidate the role that prostate may play as an endocrine organ. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. The relationship between technical parameters of external beam radiation therapy and complications for localized prostate cancer

    International Nuclear Information System (INIS)

    Kitamura, Kei; Shirato, Hiroki; Suzuki, Keishiro

    2000-01-01

    This study was performed to review retrospectively the clinical course of chronic rectal bleeding as a complication of external beam radiation therapy for localized prostate cancer and to analyze the relationship between technical parameters of radiation therapy and the complications. Seventy-one patients with stages A2, B and C were treated with local-field radiotherapy (total dose 52.5-66 Gy, daily dose 2.0-3.28 Gy, field area 30-81 cm 2 , number of fields 3-15 ports, planning simulations X-ray or CT-based) between 1989 and 1998 at three institutions. The protocols were consistent during this same period at these institutions. Multivariate analysis revealed pretreatment PSA and Gleason sum to be statistically significant predictors of 5 year prostatic specific antigen (PSA) relapse-free rates in a median follow-up period of 42 months (range 12-119 months). The significant risk factors for higher grading of acute morbidity were a biological equivalent dose, α/β=10 (BED 10 ) ≥65 Gy, dose per fraction ≥3.0 Gy, field area ≥42 cm 2 , fewer ports and X-ray planning simulation. However, no parameter was associated with higher grading of late morbidity. Eleven patients (15.4%) experienced a late GI complication: grade 1 (4.2%), grade 2 (9.8%), grade 3 (1.4%). The median time to occurrence of rectal bleeding was 12 months after radiotherapy and the mean duration of morbidity was 11 months. Higher total dose and dose per fraction, larger field area, fewer ports and X-ray simulation increased the grades of acute morbidity. A majority of chronic rectal bleedings were transient and responded to conservative treatment. (author)

  10. Radiation optic neuropathy after megavoltage external-beam irradiation: Analysis of time-dose factors

    International Nuclear Information System (INIS)

    Parsons, J.T.; Bova, F.J.; Million, R.R.

    1994-01-01

    To investigate the risk of radiation-induced optic neuropathy according to total radiotherapy dose and fraction size, based on both retrospective and prospectively collected data. Between October 1964 and May 1989, 215 optic nerves in 131 patients received fractionated external-beam irradiation during the treatment of primary extracranial head and neck tumors. All patients had a minimum of 3 years of ophthalmologic follow-up (range, 3 to 21 years). The clinical end point was visual acuity of 20/100 or worse as a result of optic nerve injury. Anterior ischemic optic neuropathy developed in five nerves (at mean and median times of 32 and 30 months, respectively, and a range of 2-4 years). Retrobulbar optic neuropathy developed in 12 nerves (at mean and median times of 47 and 28 months, respectively, and a range of 1-14 years). No injuries were observed in 106 optic nerves that received a total dose of <59 Gy. Among nerves that received doses of ≥ 60 Gy, the dose per fraction was more important than the total dose in producing optic neuropathy. The 15-year actuarial risk of optic compared with 47% when given in fraction sizes ≥1.9 Gy. The data also suggest an increased risk of optic nerve injury with increasing age. As there is no effective treatment of radiation-induced optic neuropathy, efforts should be directed at its prevention by minimizing the total dose, paying attention to the dose per fraction to the nerve, and using reduced field techniques where appropriate to limit the volume of tissues that receive high-dose irradiation. 32 refs., 5 figs., 5 tabs

  11. Can multiparametric MRI replace Roach equations in staging prostate cancer before external beam radiation therapy?

    International Nuclear Information System (INIS)

    Girometti, Rossano; Signor, Marco Andrea; Pancot, Martina; Cereser, Lorenzo; Zuiani, Chiara

    2016-01-01

    Purpose: To investigate the agreement between Roach equations (RE) and multiparametric magnetic resonance imaging (mpMRI) in assessing the T-stage of prostate cancer (PCa). Materials and methods: Seventy-three patients with biopsy-proven PCa and previous RE assessment prospectively underwent mpMRI on a 3.0T magnet before external beam radiation therapy (EBRT). Using Cohen’s kappa statistic, we assessed the agreement between RE and mpMRI in defining the T-stage (≥T3 vs.T ≤ 2) and risk category according to the National comprehensive cancer network criteria (≤intermediate vs. ≥high). We also calculated sensitivity and specificity for ≥T3 stage in an additional group of thirty-seven patients with post-prostatectomy histological examination (mpMRI validation group). Results: The agreement between RE and mpMRI in assessing the T stage and risk category was moderate (k = 0.53 and 0.56, respectively). mpMRI changed the T stage and risk category in 21.9% (95%C.I. 13.4–33-4) and 20.5% (95%C.I. 12.3–31.9), respectively, prevalently downstaging PCa compared to RE. Sensitivity and specificity for ≥T3 stage in the mpMRI validation group were 81.8% (95%C.I. 65.1–91.9) and 88.5% (72.8–96.1). Conclusion: RE and mpMRI show moderate agreement only in assessing the T-stage of PCa, translating into an mpMRI-induced change in risk assessment in about one fifth of patients. As supported by high sensitivity/specificity for ≥T3 stage in the validation group, the discrepancy we found is in favour of mpMRI as a tool to stage PCa before ERBT.

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

    International Nuclear Information System (INIS)

    Swisher-McClure, Samuel; Mitra, Nandita; Woo, Kaitlin; Smaldone, Marc; Uzzo, Robert; Bekelman, Justin E.

    2014-01-01

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

  13. External beam irradiation for retinoblastoma: patterns of failure and dose-response analysis

    International Nuclear Information System (INIS)

    Foote, R.L.; Garretson, B.R.; Schomberg, P.J.; Buskirk, S.J.; Robertson, D.M.; Earle, J.D.

    1989-01-01

    Eighteen children with retinoblastoma (25 eyes) were treated with external beam radiation at the Mayo Clinic between January 1977 and January 1987; 15 eyes were in groups I to III and 10 were in groups IV and V. The median number of tumors per eye was 3. Radiation therapy consisted of 4- or 6-MV photons. Doses varied from 39 to 51 Gy in 1.8- to 3.0-Gy fractions. Fourteen eyes were treated through lateral fields by anterior segment-sparing techniques, and 11 eyes were treated by an anterior approach with no attempt at anterior segment sparing. All patients survived (median follow-up, 31.5 months). Cataracts developed in five eyes at a median of 23 months, four in eyes treated with anterior segment-sparing techniques. Of the 15 group I to III eyes, 6 required additional treatment; 4 were salvaged with cryotherapy or photocoagulation and 2 were enucleated. Of the 10 group IV and V eyes, 8 required additional treatment; 4 were salvaged with cryotherapy or photocoagulation, 1 with persistent disease is being followed closely, and 3 were enucleated. Ten (71%) of the 14 eyes treated with anterior segment-sparing techniques required additional treatment. Four (36%) of the 11 eyes treated with an anterior approach required additional treatment. Ninety percent of the tumors 10 disc diameters or smaller (1 disc diameter = 1.6 mm) were controlled independently of dose and fractionation used when they were not in the low-dose area of the anterior retina of an eye treated with an anterior segment-sparing technique. We find that use of lateral, anterior segment-sparing techniques has a high risk of anterior retinal tumor development and cataract formation and should be abandoned in favor of techniques that treat the entire retina

  14. External beam irradiation for retinoblastoma: patterns of failure and dose-response analysis

    Energy Technology Data Exchange (ETDEWEB)

    Foote, R.L.; Garretson, B.R.; Schomberg, P.J.; Buskirk, S.J.; Robertson, D.M.; Earle, J.D.

    1989-03-01

    Eighteen children with retinoblastoma (25 eyes) were treated with external beam radiation at the Mayo Clinic between January 1977 and January 1987; 15 eyes were in groups I to III and 10 were in groups IV and V. The median number of tumors per eye was 3. Radiation therapy consisted of 4- or 6-MV photons. Doses varied from 39 to 51 Gy in 1.8- to 3.0-Gy fractions. Fourteen eyes were treated through lateral fields by anterior segment-sparing techniques, and 11 eyes were treated by an anterior approach with no attempt at anterior segment sparing. All patients survived (median follow-up, 31.5 months). Cataracts developed in five eyes at a median of 23 months, four in eyes treated with anterior segment-sparing techniques. Of the 15 group I to III eyes, 6 required additional treatment; 4 were salvaged with cryotherapy or photocoagulation and 2 were enucleated. Of the 10 group IV and V eyes, 8 required additional treatment; 4 were salvaged with cryotherapy or photocoagulation, 1 with persistent disease is being followed closely, and 3 were enucleated. Ten (71%) of the 14 eyes treated with anterior segment-sparing techniques required additional treatment. Four (36%) of the 11 eyes treated with an anterior approach required additional treatment. Ninety percent of the tumors 10 disc diameters or smaller (1 disc diameter = 1.6 mm) were controlled independently of dose and fractionation used when they were not in the low-dose area of the anterior retina of an eye treated with an anterior segment-sparing technique. We find that use of lateral, anterior segment-sparing techniques has a high risk of anterior retinal tumor development and cataract formation and should be abandoned in favor of techniques that treat the entire retina.

  15. External beam irradiation of craniopharyngiomas: long-term analysis of tumor control and morbidity

    International Nuclear Information System (INIS)

    Varlotto, John M.; Flickinger, John C.; Kondziolka, Douglas; Lunsford, L.D.; Deutsch, Melvin

    2002-01-01

    Purpose: To delineate the long-term control and morbidity with external beam radiotherapy (EBRT) of craniopharyngiomas. Methods and Materials: Between 1971 and 1992, 24 craniopharyngioma patients underwent EBRT at the University of Pittsburgh. Most (19 of 24) were treated within 1-3 months after subtotal resection. The other prior surgical procedures were biopsy (n = 2) and gross total resection (n = 1); 2 patients did not undergo any surgical procedure. The median follow-up was 12.1 years. The median patient age was 29 years (range 5-69). The total radiation doses varied from 36 to 70 Gy (median 59.75). The normalized total dose (NTD, biologically equivalent dose given in 2 Gy/fraction [α/β ratio = 2]) varied from 28 to 83 Gy (median 55.35). Results: The actuarial survival rate at 10 and 20 years was 100% and 92.3%, respectively. The actuarial local control rate at 10 and 20 years was 89.1% and 54.0%, respectively. No local failures occurred with doses ≥60 Gy (n=12) or NTDs ≥55 Gy. The complication-free survival rate at 10 and 20 years was 80.1% and 72.1%, respectively. No complications were noted with an NTD of ≤55 Gy. The actuarial survival free from any adverse outcome (recurrence or complication) was 70.1% and 31.8% at 10 and 20 years, respectively. The adverse outcome-free survival appeared optimized (at 73%) with an NTD of 55-63 Gy. Multivariate analysis found that tumor control correlated significantly with the total dose (p=0.02), treatment complications with NTD (p=0.008), and adverse outcome with hypopituitarism on presentation (p=0.03). Conclusion: We recommend treating craniopharyngioma with 1.6-1.7-Gy dose fractions to 60 Gy to optimize outcome from EBRT

  16. Combined external-beam PIXE and {mu}-Raman characterisation of garnets used in Merovingian jewellery

    Energy Technology Data Exchange (ETDEWEB)

    Calligaro, T. E-mail: thomas.calligaro@culture.gouv.fr; Colinart, S.; Poirot, J.-P.; Sudres, C

    2002-04-01

    Red garnets were the dominant gemstones used for jewels in Europe during the Early Middle Ages. We have studied over 350 garnets set on 12 jewels unearthed in the royal necropolis of the Saint-Denis Basilica, close to Paris. This famous collection of 'cloisonne' style artefacts dates from the Merovingian period (late fifth century AD to early seventh century AD). The archaeological issue addressed is the identification of the geographical origin of these garnets, in view to establish the gem trading routes during the Dark Ages. External beam PIXE was used to determine the major constituents (Mg, Al, Si, Ca, Mn, Fe), specifying the garnet type (composition in various mineralogical end-members, e.g. almandine, pyrope, spessartite, ...), and the trace element content (Cr, Y). Three sorts of garnets were identified. Ten jewels are adorned with almandine garnets (Fe-rich). One jewel has intermediate almandine-pyrope garnets ('rhodolite'). The last and most recent jewel is inlaid with pyrope (Mg-rich) garnets. Trace element content and slight differences in major composition allowed to distinguish five different sources: two sources for pyrope garnets (with and without chromium), and two sources for almandine garnets (distinctive calcium, magnesium and yttrium contents). A preliminary comparison with literature data suggested that almandine garnets may have been mined from India while the 'rhodolite' garnets may have been imported from Sri Lanka. The sources of pyrope garnets could be the Bohemian deposits (Czech republic). In addition, {mu}-Raman spectrometry was used to identify most of the mineral inclusions (apatite, zircon, ilmenite, monazite, calcite, quartz) present in almandine garnets. Even if two specific types of inclusions were not identified, due to the lack of corresponding reference spectra in our database, the Raman spectra collected provided an interesting inclusion fingerprint.

  17. Radiation retinopathy after external-beam irradiation: Analysis of time-dose factors

    International Nuclear Information System (INIS)

    Parsons, J.T.; Bova, F.J.; Mendenhall, W.M.

    1994-01-01

    To investigate the risk of radiation-induced retinopathy according to total radiation dose and fraction size, based on both retorspective and prospectively collected data. Between October 1964 and May 1989, 68 retinae in 64 patients received fractionated external-beam irradiation during the treatment of primary extracranial head and neck tumors. All patients had a minimum of 3 years of ophthalmologic follow-up (range, 3 to 26 years; mean, 9 years; median, 8 years). Twenty-seven eyes in 26 patients developed radiation retinopathy resulting in visual acuity of 20/200 or worse. The mean and median times to the onset of symptoms attributable to retinal ischemia were 2.8 and 2.5 years, respectively. Fourteen of the injured eyes developed rubeosis iridis and/or neovascular glaucoma. Radiation retinopathy was not observed at doses below 45 Gy, but increased steadily in incidence at doses ≥45Gy. In the range of doses between 45 and 55 Gy, there was an increased risk of injury among patients who received doses per fraction of ≥1.9Gy (p - .09). There was also a trend toward increased risk of injury among patients who received chemotherapy (two of two vs. four of ten in the 45-51 Gy range; p - .23). The lowest dose associated with retinopathy was 45 Gy delivered to a diabetic patient by twice-a-day fractionation. The data did not suggest an increased risk of radiation retinopathy with increasing age. The current study suggests the importance of total dose as well as dose per fraction, and adds support to a small body of literature suggesting that patients with diabetes mellitus or who receive chemotherapy are at increased risk of injury. A sigmoid dose-response curve is constructed from our current data and data from the literature. 36 refs., 5 figs., 4 tabs

  18. Impact of cradle immobilization on setup reproducibility during external beam radiation therapy for lung cancer

    International Nuclear Information System (INIS)

    Bentel, Gunilla C.; Marks, Lawrence B.; Krishnamurthy, Rupa

    1997-01-01

    Purpose: To compare the setup accuracy during fractionated radiation therapy for two patient groups with lung cancer treated with and without an immobilization cradle. Methods: Three hundred ninety-seven port films from 30 patients immobilized in the Alpha Cradle TM1 were compared with 329 port films from 30 patients who were not immobilized with the cradle. All patients were treated with curative intent for nonmetastatic lung cancer. The frequency of physician-requested isocenter shifts were compared in the two groups using a two-tailed chi-square test. Initial port films taken on the first day of treatment, routine films taken usually weekly during radiation therapy, and requested films taken after a requested shift were considered separately. The immobilization device consisted of a custom-made foam cradle that extended from above the head to the knees. Patients were generally treated with their arms above their heads, and treatment setup marks in the immobilized patients were placed on both the patients' skin and the immobilization cradle. For the noncradle patients, setup marks were placed only on the patients' skin. Results: For the routine films, the frequency of physician-requested isocenter shifts was lower in immobilized patients than in the nonimmobilized group (p = 0.139). Most of this reduction was seen on oblique fields (p = 0.038). No benefits were seen among initial or requested films. The two groups were well balanced with regard to stage, age, field size, and total dose. Conclusions: The use of aggressive immobilization improves the setup reproducibility in patients receiving external beam radiation therapy for lung cancer, especially during treatment with oblique fields. This improvement in treatment accuracy might improve the therapeutic ratio

  19. External beam radiotherapy for painful osseous metastases: pooled data dose response analysis

    International Nuclear Information System (INIS)

    Ben-Josef, Edgar; Shamsa, Falah; Youssef, Emad; Porter, Arthur T.

    1999-01-01

    Purpose: Although the effectiveness of external beam irradiation in palliation of pain from osseous metastases is well established, the optimal fractionation schedule has not been determined. Clinical studies to date have failed to demonstrate an advantage for higher doses. To further address this issue, we conducted a pooled dose response analysis using data from published Phase III clinical trials. Methods and Materials: Complete response (CR) was used as an endpoint because it was felt to be least susceptible to inconsistencies in assessment.The biological effective dose (BED) was calculated for each schedule using the linear-quadratic model and an α/β of 10. Using SAS version 6.12, the data were fitted using a weighted linear regression, a logistic model, and the spline technique. Finally, BED was categorized, and odds ratios for each level were calculated. Results: CR was assessed early and late in 383 and 1,007 patients, respectively. Linear regression on the early-response data yielded a poor fit and a nonsignificant dose coefficient. With the late-response data, there was an excellent fit (R-square = 0.842) and a highly significant dose coefficient (p = 0.0002). Fitting early CR to a logistic model, we could not establish a significant dose response relationship. However, with the late-response data there was an excellent fit and the dose coefficient was significantly different from zero (0.017 ± 0.00524; p = 0.0012). Application of the spline technique or removal of an outlier resulted in an improved fit (p 0.048 and p = 0.0001, respectively). Using BED of < 14.4 Gy as a reference level, the odds ratios for late CR were 2.29-3.32 (BED of 19.5-51.4 Gy, respectively). Conclusion: Our results demonstrate a clear dose-response for pain relief. Further testing of high intensity regiments is warranted

  20. An Optimized Online Verification Imaging Procedure for External Beam Partial Breast Irradiation

    International Nuclear Information System (INIS)

    Willis, David J.; Kron, Tomas; Chua, Boon

    2011-01-01

    The purpose of this study was to evaluate the capabilities of a kilovoltage (kV) on-board imager (OBI)-equipped linear accelerator in the setting of on-line verification imaging for external-beam partial breast irradiation. Available imaging techniques were optimized and assessed for image quality using a modified anthropomorphic phantom. Imaging dose was also assessed. Imaging techniques were assessed for physical clearance between patient and treatment machine using a volunteer. Nonorthogonal kV image pairs were identified as optimal in terms of image quality, clearance, and dose. After institutional review board approval, this approach was used for 17 patients receiving accelerated partial breast irradiation. Imaging was performed before every fraction verification with online correction of setup deviations >5 mm (total image sessions = 170). Treatment staff rated risk of collision and visibility of tumor bed surgical clips where present. Image session duration and detected setup deviations were recorded. For all cases, both image projections (n = 34) had low collision risk. Surgical clips were rated as well as visualized in all cases where they were present (n = 5). The average imaging session time was 6 min, 16 sec, and a reduction in duration was observed as staff became familiar with the technique. Setup deviations of up to 1.3 cm were detected before treatment and subsequently confirmed offline. Nonorthogonal kV image pairs allowed effective and efficient online verification for partial breast irradiation. It has yet to be tested in a multicenter study to determine whether it is dependent on skilled treatment staff.

  1. 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.

  2. Can multiparametric MRI replace Roach equations in staging prostate cancer before external beam radiation therapy?

    Energy Technology Data Exchange (ETDEWEB)

    Girometti, Rossano, E-mail: rgirometti@sirm.org [Institute of Diagnostic Radiology, Department of Medical and Biological Sciences, University of Udine, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia − via Colugna, 50–33100, Udine (Italy); Signor, Marco Andrea, E-mail: marco.signor@asuiud.sanita.fvg.it [Department of Oncological Radiation Therapy, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia, Piazzale S. M. della Misericordia, 15–33100, Udine (Italy); Pancot, Martina, E-mail: martypancot@libero.it [Institute of Diagnostic Radiology, Department of Medical and Biological Sciences, University of Udine, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia − via Colugna, 50–33100, Udine (Italy); Cereser, Lorenzo, E-mail: lcereser@sirm.org [Institute of Diagnostic Radiology, Department of Medical and Biological Sciences, University of Udine, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia − via Colugna, 50–33100, Udine (Italy); Zuiani, Chiara, E-mail: chiara.zuiani@uniud.it [Institute of Diagnostic Radiology, Department of Medical and Biological Sciences, University of Udine, Azienda Ospedaliero-Universitaria Santa Maria della Misericordia − via Colugna, 50–33100, Udine (Italy)

    2016-12-15

    Purpose: To investigate the agreement between Roach equations (RE) and multiparametric magnetic resonance imaging (mpMRI) in assessing the T-stage of prostate cancer (PCa). Materials and methods: Seventy-three patients with biopsy-proven PCa and previous RE assessment prospectively underwent mpMRI on a 3.0T magnet before external beam radiation therapy (EBRT). Using Cohen’s kappa statistic, we assessed the agreement between RE and mpMRI in defining the T-stage (≥T3 vs.T ≤ 2) and risk category according to the National comprehensive cancer network criteria (≤intermediate vs. ≥high). We also calculated sensitivity and specificity for ≥T3 stage in an additional group of thirty-seven patients with post-prostatectomy histological examination (mpMRI validation group). Results: The agreement between RE and mpMRI in assessing the T stage and risk category was moderate (k = 0.53 and 0.56, respectively). mpMRI changed the T stage and risk category in 21.9% (95%C.I. 13.4–33-4) and 20.5% (95%C.I. 12.3–31.9), respectively, prevalently downstaging PCa compared to RE. Sensitivity and specificity for ≥T3 stage in the mpMRI validation group were 81.8% (95%C.I. 65.1–91.9) and 88.5% (72.8–96.1). Conclusion: RE and mpMRI show moderate agreement only in assessing the T-stage of PCa, translating into an mpMRI-induced change in risk assessment in about one fifth of patients. As supported by high sensitivity/specificity for ≥T3 stage in the validation group, the discrepancy we found is in favour of mpMRI as a tool to stage PCa before ERBT.

  3. Targeted Intraoperative Radiotherapy for Breast Cancer in Patients in Whom External Beam Radiation Is Not Possible

    International Nuclear Information System (INIS)

    Keshtgar, Mohammed R.S.; Vaidya, Jayant S.; Tobias, Jeffrey S.; Wenz, Frederik; Joseph, David; Stacey, Chris; Metaxas, Marinos G.; Keller, Anke; Corica, Tammy; Williams, Norman R.; Baum, Michael

    2011-01-01

    Purpose: External beam radiation therapy (EBRT) following wide local excision of the primary tumor is the standard treatment in early breast cancer. In some circumstances this procedure is not possible or is contraindicated or difficult. The purpose of this study was to determine the safety and efficacy of targeted intraoperative radiotherapy (TARGIT) when EBRT is not feasible. Methods and Materials: We report our experience with TARGIT in three centers (Australia, Germany, and the United Kingdom) between 1999 and 2008. Patients at these centers received a single radiation dose of 20 Gy to the breast tissue in contact with the applicator (or 6 Gy at 1-cm distance), as they could not be given EBRT and were keen to avoid mastectomy. Results: Eighty patients were treated with TARGIT. Reasons for using TARGIT were 21 patients had previously received EBRT, and 31 patients had clinical reasons such as systemic lupus erythematosus, motor neuron disease, Parkinson's disease, ankylosing spondylitis, morbid obesity, and cardiovascular or severe respiratory disease. Three of these patients received percutaneous radiotherapy without surgery; 28 patients were included for compelling personal reasons, usually on compassionate grounds. After a median follow-up of 38 months, only two local recurrences were observed, an annual local recurrence rate of 0.75% (95% confidence interval, 0.09%-2.70%). Conclusions: While we await the results of the randomized trial (over 2,000 patients have already been recruited), TARGIT is an acceptable option but only in highly selected cases that cannot be recruited in the trial and in whom EBRT is not feasible/possible.

  4. External-beam boost prior to total-body irradiation in relapsed NHL transplant patients

    Energy Technology Data Exchange (ETDEWEB)

    Monson, Jedidiah M; Neuberg, Donna; Freedman, Arnold S; Tarbell, Nancy J; Nadler, Lee M; Mauch, Peter

    1995-07-01

    PURPOSE: To determine the impact of an external beam boost (EBB) on the outcome, relapse pattern and normal tissue toxicities of patients undergoing total-body irradiation (TBI) prior to bone marrow transplantation (BMT) for relapsed NHL. MATERIALS AND METHODS: Between 1982 and 1994, 299 patients at our institution underwent BMT for relapsed NHL. Patients underwent induction chemotherapy (CT) followed by conditioning with cyclophosphamide and 12 Gy TBI delivered in 6 fractions over 3 days. A total of 77 patients had persistent gross disease, defined as 2 cm or greater, after induction CT and received an EBB prior to BMT (EBB cohort). The median EBB dose was 28.8 Gy (range, 5-63), the median field size was 13 cm{sup 2} (range, 5-29.4) and the median time from EBB to BMT was 3 weeks (range, 1-20). A total of 222 patients were free of measurable disease or had disease measuring <2cm after CT and did not receive EBB (no-EBB cohort). To assess normal tissue toxicity, patients' simulation films and/or treatment records were reviewed for all 77 patients treated with local EBB and estimates were made of the percentage lung, heart and kidney in the radiation field. RESULTS: A total of 79 of 222 patients (36%) in the no-EBB cohort have relapsed; 33 of 77 patients (43%) in the EBB cohort have relapsed (p=0.28, by Fisher exact test). Median time to relapse after BMT was 54 months for the no-EBB cohort and 38 months for the EBB cohort (p=0.26, by log-rank test). The 3-year actuarial freedom from relapse (deaths in remission censored) was 59% for the no-EBB cohort (90% CI: 52-66%) and 51% for the EBB cohort (90% CI: 40-62%). Data on site of relapse was available for 101 of the 112 relapses (75 no-EBB, 26 EBB). For the no-EBB cohort 33 of 75 relapses (44%) were in sites of prior nodal disease only. For the EBB cohort, 12 of 26 relapses (46%) were in sites of prior nodal disease only, of these, only 6 (23%) were within the EBB treatment field. A total of 26 patients had thoracic

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

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

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

    International Nuclear Information System (INIS)

    Andreo, P.

    2001-01-01

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

  7. New ICRU quantities for the environmental and individual monitoring. Standardization of individual dosemeters by using external beams of photon radiation

    International Nuclear Information System (INIS)

    Brosed, A.; Delgado, A.; Granados, C. E.

    1987-01-01

    The quantities introduced by ICRU for the radiological monitoring are commented, specially those implied in individual protection against external photons. A procedure is proposed in order to standardize the individual dosemeters by using the kerma in air references of CIEMAT-JEN. The reference radiation beams are described in connection with ISO standards. Provisional values are selected for the appropriate conversion and correction factors. (Author) 23 refs

  8. Pain flare following external beam radiotherapy and meaningful change in pain scores in the treatment of bone metastases

    International Nuclear Information System (INIS)

    Chow, Edward; Ling, Alison; Davis, Lori; Panzarella, Tony; Danjoux, Cyril

    2005-01-01

    Background and purpose: To examine the incidence of pain flare following external beam radiotherapy and to determine what constitutes a meaningful change in pain scores in the treatment of bone metastases. Patients and methods: Patients with bone metastases treated with external beam radiotherapy were asked to score their pain on a scale of 0-10 before the treatment (baseline), daily during the treatment and for 10 days after completion of external beam radiation. Pain flare was defined as a two-point increase from baseline pain in the pain scale of 0-10 with no decrease in analgesic intake or a 25% increase in analgesic intake employing daily oral morphine equivalent with no decrease in pain score. To distinguish pain flare from progression of pain, we required the pain score and analgesic intake to return back to baseline levels after the increase/flare. They were also asked to indicate if their pain changed during that time compared to pre-treatment level. The change in pain score was compared with patient perception. Results: Eighty-eight patients were evaluated in this study. There were 49 male and 39 female patients with the median age of 70 years. Twelve of 88 patients (14%) had pain flare on day 1. The overall incidence of pain flare during the study period ranged from 2 to 16%. A total of 797 pain scorings were obtained. Patients perceived an improvement in pain when their self-reported pain score decreased by at least two points. Conclusions: Our study confirms the occurrence of pain flare following the external beam radiotherapy in the treatment of bone metastases. Further studies are required to predict who are at risk for flare. Appropriate measures can be taken to alleviate the pain flare. The finding in the meaningful change in pain scores supports the investigator-defined partial response used in some clinical trials

  9. Parametric oesophageal multiple swallow scintigraphy for validation of dysphageal symptoms during external beam irradiation of mediastinal tumours

    Energy Technology Data Exchange (ETDEWEB)

    Brandt-Mainz, K.; Eising, E.G.; Bockisch, A. [Essen Univ. (Gesamthochschule) (Germany). Klinik und Poliklinik fuer Nuklearmedizin; Mallek, D. von; Poettgen, C.; Stuschke, M.; Sack, H. [Klinik und Poliklinik fuer Strahlentherapie, Universitaetsklinikum Essen (Germany)

    2001-03-01

    The aim of the study was to evaluate dysphageal symptoms and to measure the effect of local analgesic treatment using parametric oesophageal multiple swallow scintigraphy (PES) during external beam irradiation of the mediastinal region. Fifteen patients (most with lung cancer) with dysphagia grade II underwent PES during external beam radiotherapy of the mediastinum before and after application of local analgesics. Dynamic parametric condensed images were recorded. The intensity of clinical symptoms was correlated with the emptying rate at 10 s (ER-10 s) and the mean transit time (MTT). Visual analysis of the images was performed and the results were correlated with the fields of irradiation portals. Of the 15 patients, 12 showed a correlation between irradiation portals and the region of oesophageal motility disorder. Concordant results of clinical symptoms and PES data were found. In nine patients with a decrease in dysphagia following local analgesia, an increase in mean ER-10 s and a decrease in MTT were observed. In three patients with deterioration in clinical symptoms after analgesic treatment, a similar decrease in mean ER-10 s was found, though MTT remained constant. In three patients with normal values, motility disorders were detected in the dynamic study. In conclusion, PES was found to be a sensitive tool for the validation of dysphageal symptoms in patients during external beam irradiation of mediastinal tumours and for the evaluation and quantification of the efficacy of local analgesic treatment. Additional visual analysis of the dynamic study is helpful in diagnosing minimal disorders. (orig.)

  10. Parametric oesophageal multiple swallow scintigraphy for validation of dysphageal symptoms during external beam irradiation of mediastinal tumours

    International Nuclear Information System (INIS)

    Brandt-Mainz, K.; Eising, E.G.; Bockisch, A.

    2001-01-01

    The aim of the study was to evaluate dysphageal symptoms and to measure the effect of local analgesic treatment using parametric oesophageal multiple swallow scintigraphy (PES) during external beam irradiation of the mediastinal region. Fifteen patients (most with lung cancer) with dysphagia grade II underwent PES during external beam radiotherapy of the mediastinum before and after application of local analgesics. Dynamic parametric condensed images were recorded. The intensity of clinical symptoms was correlated with the emptying rate at 10 s (ER-10 s) and the mean transit time (MTT). Visual analysis of the images was performed and the results were correlated with the fields of irradiation portals. Of the 15 patients, 12 showed a correlation between irradiation portals and the region of oesophageal motility disorder. Concordant results of clinical symptoms and PES data were found. In nine patients with a decrease in dysphagia following local analgesia, an increase in mean ER-10 s and a decrease in MTT were observed. In three patients with deterioration in clinical symptoms after analgesic treatment, a similar decrease in mean ER-10 s was found, though MTT remained constant. In three patients with normal values, motility disorders were detected in the dynamic study. In conclusion, PES was found to be a sensitive tool for the validation of dysphageal symptoms in patients during external beam irradiation of mediastinal tumours and for the evaluation and quantification of the efficacy of local analgesic treatment. Additional visual analysis of the dynamic study is helpful in diagnosing minimal disorders. (orig.)

  11. MO-A-BRB-01: Review of TG-262 Internal Survey of Practices in EMR for External Beam Therapy

    International Nuclear Information System (INIS)

    Mechalakos, J.

    2015-01-01

    The process of converting to an electronic chart for radiation therapy can be daunting. It requires a dedicated committee to first research and choose appropriate software, to review the entire documentation policy and flow of the clinic, to convert this system to electronic form or if necessary, redesign the system to more easily conform to the electronic process. Those making the conversion and those who already use electronic charting would benefit from the shared experience of those who have been through the process in the past. Therefore TG262 was convened to provide guidance on electronic charting for external beam radiation therapy and brachytherapy. This course will present the results of an internal survey of task group members on EMR practices in External Beam Radiation Therapy as well as discuss important issues in EMR development and structure for both EBRT and brachytherapy. Learning Objectives: Be familiarized with common practices and pitfalls in development and maintenance of an electronic chart in Radiation Oncology Be familiarized with important issues related to electronic charting in External Beam Radiation Therapy Be familiarized with important issues related to electronic charting in Brachytherapy

  12. On Interactions of Oscillation Modes for a Weakly Non-Linear Undamped Elastic Beam with AN External Force

    Science.gov (United States)

    BOERTJENS, G. J.; VAN HORSSEN, W. T.

    2000-08-01

    In this paper an initial-boundary value problem for the vertical displacement of a weakly non-linear elastic beam with an harmonic excitation in the horizontal direction at the ends of the beam is studied. The initial-boundary value problem can be regarded as a simple model describing oscillations of flexible structures like suspension bridges or iced overhead transmission lines. Using a two-time-scales perturbation method an approximation of the solution of the initial-boundary value problem is constructed. Interactions between different oscillation modes of the beam are studied. It is shown that for certain external excitations, depending on the phase of an oscillation mode, the amplitude of specific oscillation modes changes.

  13. Endometrial cancer - reduce to the minimum. A new paradigm for adjuvant treatments?

    International Nuclear Information System (INIS)

    Scheithauer, Heike R; Schulz, Diana S; Belka, Claus

    2011-01-01

    Up to now, the role of adjuvant radiation therapy and the extent of lymph node dissection for early stage endometrial cancer are controversial. In order to clarify the current position of the given adjuvant treatment options, a systematic review was performed. Both, Pubmed and ISI Web of Knowledge database were searched using the following keywords and MESH headings: 'Endometrial cancer', 'Endometrial Neoplasms', 'Endometrial Neoplasms/radiotherapy', 'External beam radiation therapy', 'Brachytherapy' and adequate combinations. Recent data from randomized trials indicate that external beam radiation therapy - particularly in combination with extended lymph node dissection - or radical lymph node dissection increases toxicity without any improvement of overall survival rates. Thus, reduced surgical aggressiveness and limitation of radiotherapy to vaginal-vault-brachytherapy only is sufficient for most cases of early stage endometrial cancer

  14. Dose-modeling study to compare external beam techniques from protocol NSABP B-39/RTOG 0413 for patients with highly unfavorable cardiac anatomy

    International Nuclear Information System (INIS)

    Hiatt, Jessica R.; Evans, Suzanne B.; Price, Lori Lyn; Cardarelli, Gene A.; Di Petrillo, Thomas A.; Wazer, David E.

    2006-01-01

    Purpose: The aim of this study was to select patients with heart anatomy that is specifically unfavorable for tangential irradiation in whole-breast radiotherapy (WBRT), to be used as an experimental cohort to compare cardiac dosimetric and radiobiological parameters of three-dimensional conformal external beam accelerated partial breast irradiation (3D-CRT APBI) to WBRT with techniques as defined by the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-39/Radiation Therapy Oncology Group (RTOG) 0413 clinical trial. Methods and Materials: A dosimetric modeling study that compared WBRT and 3D-CRT APBI was performed on CT planning data from 8 patients with left-sided breast cancer. Highly unfavorable cardiac anatomy was defined by the measured contact of the myocardium with the anterior chest wall in the axial and para-sagittal planes. Treatment plans of WBRT and 3D-CRT APBI were generated for each patient in accordance with NSABP B-39/RTOG 0413 protocol. Dose-volume relationships of the heart, including the V 5 min (minimum dose delivered to 5% of the cardiac volume), biological effective dose (BED) of the V 5 min, and normal tissue complication probability (NTCP) were analyzed and compared. Results: Despite expected anatomic variation, significantly large differences were found favoring 3D-CRT APBI in cumulative dose-volume histograms (p 5 min (mean difference, 24.53 Gy; p 5 min (85%, p < 0.01). Conclusions: Use of 3D-CRT APBI can demonstrate improved sparing of the heart in select patients with highly unfavorable cardiac anatomy for WBRT, and may result in reduced risk of cardiac morbidity and mortality

  15. Less gastrointestinal toxicity after adjuvant radiotherapy on a small pelvic field compared to a standard pelvic field in patients with endometrial carcinoma

    NARCIS (Netherlands)

    de Jong, Renske A.; Pras, Elisabeth; Boezen, H. Marike; van der Zee, Ate G. J.; Mourits, Marian J. E.; Arts, Henriette J. G.; Aalders, Jan G.; Slot, Annerie; Timmer, Paul R.; Hollema, Harry; Nijman, Hans W.

    Objective: Radiotherapy is associated with short-term and long-term morbidity. This study compared toxicity rates among patients with endometrial carcinoma (EC) treated with adjuvant external beam radiation therapy (EBRT) on a small pelvic field (SmPF) in comparison with a standard pelvic field

  16. Reinforced concrete T-beams externally prestressed with unbonded carbon fiber-reinforced polymer tendons

    DEFF Research Database (Denmark)

    Bennitz, Anders; Nilimaa, Jonny; Täljsten, Björn

    2012-01-01

    force, and the presence of a deviator were investigated. The results were compared to those observed with analogous beams prestressed with steel tendons, common beam theory, and predictions made using an analytical model adapted from the literature. It was found that steel and CFRP tendons had very...... similar effects on the structural behavior of the strengthened beams; the minor differences that were observed are attributed to the difference between the modulus of elasticity of the CFRP and the steel used in the tests. The models predicted the beams' load-bearing behavior accurately but were less...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-15

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

  18. DOSE-ESCALATED EXTERNAL BEAM RADIOTHERAPY DURING HORMONO-RADIOTHERAPY FOR PROSTATE CANCER

    Directory of Open Access Journals (Sweden)

    Yu. V. Gumenetskaya

    2016-01-01

    Full Text Available Introduction. The introduction of modern technologies of conformal external beam radiotherapy (EBRT into clinical practice for the treatment of prostate cancer requires proper quality assurance measures as well as a careful analysis of both the efficacy and toxicity data of treatments. The purpose of this study was to inves- tigate tolerance and the immediate efficacy of conformal dose-escalated EBRT during hormono-radiotherapy for prostate cancer. material and methods. The study involved 156 prostate cancer patients treated with EBRT. Among them, 30 patients received a total dose of 70 Gy, and in 126 patients the total dose was esca- lated to 72-76 Gy (median total dose - 74.0 Gy. Fifty-nine patients received intensity modulated radiation therapy. Results. The prescribed course of treatment was completed in all the patients with prostate cancer. Acute radiation-induced bladder reactions (RTOG were observed in 50 (32.1 % patients, of whom 48 (30.8 % experienced grade I reactions, and 2 (1.3 % experienced grade II reactions. Eighteen (11.5 % patients had radiation-induced rectum reactions, not above grade I. The development of grade II dysuric phenomena necessitated treatment interruption only in two patients. Of 9 (5.8 % patients who had late bladder complica- tions (RTOG/EORTC, 8 (5.1 % patients developed grade I complications, and one (0.6 % patient developed grade II complications. Of 11 (7.1 % patients who had rectum complications, 8 (5.1 % patients developed grade I complications, and 3 (1.9 % patients developed grade II complications. No patients experienced the increase in toxicity of treatment during dose escalation up to a total dose exceeding 70 Gy. During the follow-up period, only one patient developed recurrent disease. Conclusion. The results of our study suggest acceptable levels of toxicity following a continuous course of dose-escalated EBRT given in conjunction with hormono-radiotherapy to prostate cancer patients. Further

  19. Contemporary Toxicity Profile of Breast Brachytherapy Versus External Beam Radiation After Lumpectomy for Breast Cancer

    International Nuclear Information System (INIS)

    Huo, Jinhai; Giordano, Sharon H.; Smith, Benjamin D.; Shaitelman, Simona F.; Smith, Grace L.

    2016-01-01

    Purpose: We compared toxicities after brachytherapy versus external beam radiation therapy (EBRT) in contemporary breast cancer patients. Methods and Materials: Using MarketScan healthcare claims, we identified 64,112 women treated from 2003 to 2012 with lumpectomy followed by radiation (brachytherapy vs EBRT). Brachytherapy was further classified by multichannel versus single-channel applicator approach. We identified the risks and predictors of 1-year infectious and noninfectious postoperative adverse events using logistic regression and temporal trends using Cochran-Armitage tests. We estimated the 5-year Kaplan-Meier cumulative incidence of radiation-associated adverse events. Results: A total of 4522 (7.1%) patients received brachytherapy (50.2% multichannel vs 48.7% single-channel applicator). The overall risk of infectious adverse events was higher after brachytherapy than after EBRT (odds ratio [OR] = 1.21; 95% confidence interval [CI] 1.09-1.34, P<.001). However, over time, the frequency of infectious adverse events after brachytherapy decreased, from 17.3% in 2003 to 11.6% in 2012, and was stable after EBRT at 9.7%. Beyond 2007, there were no longer excess infections with brachytherapy (P=.97). The overall risk of noninfectious adverse events was higher after brachytherapy than after EBRT (OR=2.27; 95% CI 2.09-2.47, P<.0001). Over time, the frequency of noninfectious adverse events detected increased: after multichannel brachytherapy, from 9.1% in 2004 to 18.9% in 2012 (Ptrend = .64); single-channel brachytherapy, from 12.8% to 29.8% (Ptrend<.001); and EBRT, from 6.1% to 10.3% (Ptrend<.0001). The risk was significantly higher with single-channel than with multichannel brachytherapy (hazard ratio = 1.32; 95% CI 1.03-1.69, P=.03). Of noninfectious adverse events, 70.9% were seroma. Seroma significantly increased breast pain risk (P<.0001). Patients with underlying diabetes, cardiovascular disease, and treatment with chemotherapy had increased

  20. Safety of {sup 90}Y Radioembolization in Patients Who Have Undergone Previous External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lam, Marnix G.E.H. [Division of Interventional Radiology, Stanford University School of Medicine, Stanford, California (United States); Department of Radiology and Nuclear Medicine, University Medical Center Utrecht (Netherlands); Abdelmaksoud, Mohamed H.K. [Division of Interventional Radiology, Stanford University School of Medicine, Stanford, California (United States); Chang, Daniel T.; Eclov, Neville C.; Chung, Melody P.; Koong, Albert C. [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Louie, John D. [Division of Interventional Radiology, Stanford University School of Medicine, Stanford, California (United States); Sze, Daniel Y., E-mail: dansze@stanford.edu [Division of Interventional Radiology, Stanford University School of Medicine, Stanford, California (United States)

    2013-10-01

    Purpose: Previous external beam radiation therapy (EBRT) is theoretically contraindicated for yttrium-90 ({sup 90}Y) radioembolization (RE) because the liver has a lifetime tolerance to radiation before becoming vulnerable to radiation-induced liver disease. We analyzed the safety of RE as salvage treatment in patients who had previously undergone EBRT. Methods and Materials: Between June 2004 and December 2010, a total of 31 patients who had previously undergone EBRT were treated with RE. Three-dimensional treatment planning with dose–volume histogram (DVH) analysis of the liver was used to calculate the EBRT liver dose. Liver-related toxicities including RE-induced liver disease (REILD) were reviewed and classified according to Common Terminology Criteria for Adverse Events version 4.02. Results: The mean EBRT and RE liver doses were 4.40 Gy (range, 0-23.13 Gy) and 57.9 Gy (range, 27.0-125.9 Gy), respectively. Patients who experienced hepatotoxicity (≥grade2; n=12) had higher EBRT mean liver doses (7.96 ± 8.55 Gy vs 1.62 ± 3.39 Gy; P=.037), the only independent predictor in multivariate analysis. DVH analysis showed that the fraction of liver exposed to ≥30 Gy (V30) was the strongest predictor of hepatotoxicity (10.14% ± 12.75% vs 0.84% ± 3.24%; P=.006). All patients with V30 >13% experienced hepatotoxicity. Fatal REILD (n=2) occurred at the 2 highest EBRT mean liver doses (20.9 Gy and 23.1 Gy) but also at the highest cumulative liver doses (91.8 Gy and 149 Gy). Conclusions: Prior exposure of the liver to EBRT may lead to increased liver toxicity after RE treatment, depending on fractional liver exposure and dose level. The V30 was the strongest predictor of toxicity. RE appears to be safe for the treatment of hepatic malignancies only in patients who have had limited hepatic exposure to prior EBRT.

  1. Contemporary Toxicity Profile of Breast Brachytherapy Versus External Beam Radiation After Lumpectomy for Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Huo, Jinhai [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Giordano, Sharon H. [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D. [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Shaitelman, Simona F. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Grace L., E-mail: glsmith@mdanderson.org [Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-03-15

    Purpose: We compared toxicities after brachytherapy versus external beam radiation therapy (EBRT) in contemporary breast cancer patients. Methods and Materials: Using MarketScan healthcare claims, we identified 64,112 women treated from 2003 to 2012 with lumpectomy followed by radiation (brachytherapy vs EBRT). Brachytherapy was further classified by multichannel versus single-channel applicator approach. We identified the risks and predictors of 1-year infectious and noninfectious postoperative adverse events using logistic regression and temporal trends using Cochran-Armitage tests. We estimated the 5-year Kaplan-Meier cumulative incidence of radiation-associated adverse events. Results: A total of 4522 (7.1%) patients received brachytherapy (50.2% multichannel vs 48.7% single-channel applicator). The overall risk of infectious adverse events was higher after brachytherapy than after EBRT (odds ratio [OR] = 1.21; 95% confidence interval [CI] 1.09-1.34, P<.001). However, over time, the frequency of infectious adverse events after brachytherapy decreased, from 17.3% in 2003 to 11.6% in 2012, and was stable after EBRT at 9.7%. Beyond 2007, there were no longer excess infections with brachytherapy (P=.97). The overall risk of noninfectious adverse events was higher after brachytherapy than after EBRT (OR=2.27; 95% CI 2.09-2.47, P<.0001). Over time, the frequency of noninfectious adverse events detected increased: after multichannel brachytherapy, from 9.1% in 2004 to 18.9% in 2012 (Ptrend = .64); single-channel brachytherapy, from 12.8% to 29.8% (Ptrend<.001); and EBRT, from 6.1% to 10.3% (Ptrend<.0001). The risk was significantly higher with single-channel than with multichannel brachytherapy (hazard ratio = 1.32; 95% CI 1.03-1.69, P=.03). Of noninfectious adverse events, 70.9% were seroma. Seroma significantly increased breast pain risk (P<.0001). Patients with underlying diabetes, cardiovascular disease, and treatment with chemotherapy had increased

  2. External beam irradiation for choroid metastases: identification of factors predisposing to long-term sequelae

    International Nuclear Information System (INIS)

    Rudoler, Shari B.; Corn, Benjamin W.; Shields, Carol L.; De Potter, Patrick; Hyslop, Terry; Shields, Jerry A.; Curran, Walter J.

    1997-01-01

    Purpose: To improve overall quality of life, palliative treatments should attempt to minimize associated complications while effectively controlling specific symptoms. We reviewed our experience treating posterior uveal metastases with external beam radiotherapy (EBRT) to determine the complication rate and to identify the relationship between patient, tumor, or treatment-related factors and the development of ocular complications. Methods and Materials: 483 consecutive patients (pts) (578 eyes) were diagnosed with intraocular metastatic disease from solid tumors between 1972-1995. Of these, 233 eyes (188 pts) had lesions of the posterior uveal tract and received EBRT. Median follow-up time was 5.8 months (range: 0.7-170.0 months). Follow-up information regarding the development of complications was documented for 230 eyes. Complete EBRT details were available for 189 eyes. Seventy-two percent of the patients received 30.0-40.0 Gy in 2.0-3.0 Gy fractions. Biologically effective dose (BED) was calculated to allow meaningful comparisons between various fractionation regimens and total doses. Concurrent chemotherapy and/or hormonal therapy was used for 101 eyes (44%). Results: Median BED was 61 Gy 3 (range, 6.7-105 Gy 3 ), and 80% of treated eyes received BED 50-70 Gy 3 . EBRT energies included photons (70%), 60 Co (19%), electrons (6%), mixed energies (3%), and orthovoltage (2%). Lens-sparing techniques were used in 136 eyes (71%). At last follow-up 28 eyes (12%) developed one or more significant complications, including cataracts (16 eyes), radiation retinopathy (6 eyes), optic neuropathy (5 eyes), exposure keratopathy (5 eyes), and neovascularization of the iris (4 eyes). Two eyes developed narrow-angle glaucoma, and one of these required enucleation. On univariate analysis, Caucasian race (vs. Black/Hispanic, p = 0.03), increased intraocular pressure at diagnosis (>21 mmHg, p = 0.02), and diagnosis by biopsy (vs. no biopsy, p = 0.03) predisposed toward the

  3. A retrospective analysis of 140 dogs with oral melanoma treated with external beam radiation.

    Science.gov (United States)

    Proulx, David R; Ruslander, David M; Dodge, Richard K; Hauck, Marlene L; Williams, Laurel E; Horn, Birgitte; Price, G Sylvester; Thrall, Donald E

    2003-01-01

    Despite the early notion that canine oral malignant melanoma is radioresistant, recent data suggest that external beam radiotherapy is effective in local tumor control. However, optimal fractionation schedules have not been established. The high rate of regional and distant metastasis is another problem that has hindered long-term control. The role of chemotherapy in the management of canine oral melanoma has also not been determined. In this study, data from 140 dogs irradiated at North Carolina State University were evaluated with the following objectives: (1) to compare the efficacy of three radiation therapy protocols (36 Gy, 9 Gy x 4 fractions; 30 Gy, 10 Gy x 3 fractions; or >45 Gy, 2-4 Gy x 12-19 fractions) for the treatment of dogs with oral malignant melanoma, (2) to identify any host or tumor factors influencing prognosis, and (3) to determine the impact of systemic chemotherapy on treatment outcome. Information regarding response to therapy, disease progression, and survival were determined from the medical records or from information obtained by telephone or mail survey. Relationships between host, tumor, and treatment variables and outcome measures (response, time to first event, and survival) were evaluated using Fisher's exact test (response) and the Cox regression model (time to first event and survival). The median time to first event for the 140 dogs was 5.0 months (95% C.I., 4-6 months) and the median survival was 7.0 months (95% C.I., 6-9 months). In the univariate analysis, the following variables were associated with increased time to first event and survival: (1) rostral tumor sublocation; (2) lack of bone lysis observed on skull imaging, and (3) microscopic tumor burden. In a multivariate analysis of 111 dogs with complete data for these variables, tumor sublocation, bone lysis, and tumor volume were identified as joint predictors of time to first event (p oral malignant melanoma; however, the optimal fractionation scheme has yet to be

  4. Knowledge-based prediction of three-dimensional dose distributions for external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Shiraishi, Satomi; Moore, Kevin L., E-mail: kevinmoore@ucsd.edu [Department of Radiation Medicine and Applied Sciences, University of California, San Diego, La Jolla, California 92093 (United States)

    2016-01-15

    Purpose: To demonstrate knowledge-based 3D dose prediction for external beam radiotherapy. Methods: Using previously treated plans as training data, an artificial neural network (ANN) was trained to predict a dose matrix based on patient-specific geometric and planning parameters, such as the closest distance (r) to planning target volume (PTV) and organ-at-risks (OARs). Twenty-three prostate and 43 stereotactic radiosurgery/radiotherapy (SRS/SRT) cases with at least one nearby OAR were studied. All were planned with volumetric-modulated arc therapy to prescription doses of 81 Gy for prostate and 12–30 Gy for SRS. Using these clinically approved plans, ANNs were trained to predict dose matrix and the predictive accuracy was evaluated using the dose difference between the clinical plan and prediction, δD = D{sub clin} − D{sub pred}. The mean (〈δD{sub r}〉), standard deviation (σ{sub δD{sub r}}), and their interquartile range (IQR) for the training plans were evaluated at a 2–3 mm interval from the PTV boundary (r{sub PTV}) to assess prediction bias and precision. Initially, unfiltered models which were trained using all plans in the cohorts were created for each treatment site. The models predict approximately the average quality of OAR sparing. Emphasizing a subset of plans that exhibited superior to the average OAR sparing during training, refined models were created to predict high-quality rectum sparing for prostate and brainstem sparing for SRS. Using the refined model, potentially suboptimal plans were identified where the model predicted further sparing of the OARs was achievable. Replans were performed to test if the OAR sparing could be improved as predicted by the model. Results: The refined models demonstrated highly accurate dose distribution prediction. For prostate cases, the average prediction bias for all voxels irrespective of organ delineation ranged from −1% to 0% with maximum IQR of 3% over r{sub PTV} ∈ [ − 6, 30] mm. The

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

    Science.gov (United States)

    Via, Riccardo; Fassi, Aurora; Fattori, Giovanni; Fontana, Giulia; Pella, Andrea; Tagaste, Barbara; Riboldi, Marco; Ciocca, Mario; Orecchia, Roberto; Baroni, Guido

    2015-05-01

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

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

    International Nuclear Information System (INIS)

    Via, Riccardo; Fassi, Aurora; Fattori, Giovanni; Fontana, Giulia; Pella, Andrea; Tagaste, Barbara; Ciocca, Mario; Riboldi, Marco; Baroni, Guido; Orecchia, Roberto

    2015-01-01

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

  7. The value of external beam radiation in pathologic node positive prostate cancer: a multivariate analysis

    International Nuclear Information System (INIS)

    Morris, Astrid D.; Zietman, Anthony L.; Althausen, Alex F.; Heney, Niall M.; Kaufman, Donald S.; Shipley, William U.

    1997-01-01

    Purpose: The goal of this study was to evaluate the effect of local/regional treatment, particularly external beam radiation alone versus radical prostatectomy and radiation therapy in patients with pathologic node positive prostate cancer on survival. The effect of delayed vs. immediate endocrine therapy on patients treated with radiation alone was also examined. Methods: Medical records of all 116 patients who received their initial treatment at the Massachusetts General Hospital between 1980 and 1996 for adenocarcinoma of the prostate with pathologic confirmed nodal metastasis and no distant disease were reviewed. The mean follow up was 5.5 years. Disease specific survival, time to PSA failure on endocrine therapy, and time to first intervention were evaluated. PSA failure was defined as two consecutive post-nadir rises following the first use of endocrine therapy. Intervention was defined as any surgical or radiotherapeutic procedure required for relief of symptoms related to local/regional recurrence. Survival comparisons were made between any local/regional treatment vs. none, radiation therapy alone vs. prostatectomy with radiation therapy, and immediate vs. delayed endocrine therapy. The effect of the different treatment options on survival were compared using multivariate Cox proportional hazard models to simultaneously adjust for patient and tumor characteristics (tumor stage, Gleason grade, number of positive nodes) that might influence survival. Results: The combined patient population had a 5 year disease specific survival of 74% and a 10 year disease specific survival of 48%. The comparison groups for local/regional treatment had the following adjusted outcomes. In a subgroup analysis of patients with clinical T1-T2 and clinical T3-T4 disease, local/regional treatment continued to confer a disease specific survival advantage over no local regional treatment in both subgroups (p=0.05 and p=0.02, respectively). PSA failure on endocrine therapy was

  8. Comparison of Cherenkov excited fluorescence and phosphorescence molecular sensing from tissue with external beam irradiation.

    Science.gov (United States)

    Lin, Huiyun; Zhang, Rongxiao; Gunn, Jason R; Esipova, Tatiana V; Vinogradov, Sergei; Gladstone, David J; Jarvis, Lesley A; Pogue, Brian W

    2016-05-21

    Ionizing radiation delivered by a medical linear accelerator (LINAC) generates Cherenkov emission within the treated tissue. A fraction of this light, in the 600-900 nm wavelength region, propagates through centimeters of tissue and can be used to excite optical probes in vivo, enabling molecular sensing of tissue analytes. The success of isolating the emission signal from this Cherenkov excitation background is dependent on key factors such as: (i) the Stokes shift of the probe spectra; (ii) the excited state lifetime; (iii) the probe concentration; (iv) the depth below the tissue surface; and (v) the radiation dose used. Previous studies have exclusively focused on imaging phosphorescent dyes, rather than fluorescent dyes. However there are only a few biologically important phosphorescent dyes and yet in comparison there are thousands of biologically relevant fluorescent dyes. So in this study the focus was a study of efficacy of Cherenkov-excited luminescence using fluorescent commercial near-infrared probes, IRDye 680RD, IRDye 700DX, and IRDye 800CW, and comparing them to the well characterized phosphorescent probe Oxyphor PtG4, an oxygen sensitive dye. Each probe was excited by Cherenkov light from a 6 MV external radiation beam, and measured in continuous wave or time-gated modes. The detection was performed by spectrally resolving the luminescence signals, and measuring them with spectrometer-based separation on an ICCD detector. The results demonstrate that IRDye 700DX and PtG4 allowed for the maximal signal to noise ratio. In the case of the phosphorescent probe, PtG4, with emission decays on the microsecond (μs) time scale, time-gated acquisition was possible, and it allowed for higher efficacy in terms of the probe concentration and detection depth. Phantoms containing the probe at 5 mm depth could be detected at concentrations down to the nanoMolar range, and at depths into the tissue simulating phantom near 3 cm. In vivo studies showed that 5

  9. Knowledge-based prediction of three-dimensional dose distributions for external beam radiotherapy

    International Nuclear Information System (INIS)

    Shiraishi, Satomi; Moore, Kevin L.

    2016-01-01

    Purpose: To demonstrate knowledge-based 3D dose prediction for external beam radiotherapy. Methods: Using previously treated plans as training data, an artificial neural network (ANN) was trained to predict a dose matrix based on patient-specific geometric and planning parameters, such as the closest distance (r) to planning target volume (PTV) and organ-at-risks (OARs). Twenty-three prostate and 43 stereotactic radiosurgery/radiotherapy (SRS/SRT) cases with at least one nearby OAR were studied. All were planned with volumetric-modulated arc therapy to prescription doses of 81 Gy for prostate and 12–30 Gy for SRS. Using these clinically approved plans, ANNs were trained to predict dose matrix and the predictive accuracy was evaluated using the dose difference between the clinical plan and prediction, δD = D clin − D pred . The mean (〈δD r 〉), standard deviation (σ δD r ), and their interquartile range (IQR) for the training plans were evaluated at a 2–3 mm interval from the PTV boundary (r PTV ) to assess prediction bias and precision. Initially, unfiltered models which were trained using all plans in the cohorts were created for each treatment site. The models predict approximately the average quality of OAR sparing. Emphasizing a subset of plans that exhibited superior to the average OAR sparing during training, refined models were created to predict high-quality rectum sparing for prostate and brainstem sparing for SRS. Using the refined model, potentially suboptimal plans were identified where the model predicted further sparing of the OARs was achievable. Replans were performed to test if the OAR sparing could be improved as predicted by the model. Results: The refined models demonstrated highly accurate dose distribution prediction. For prostate cases, the average prediction bias for all voxels irrespective of organ delineation ranged from −1% to 0% with maximum IQR of 3% over r PTV ∈ [ − 6, 30] mm. The average prediction error was less

  10. SU-F-J-11: Radiobiologically Optimized Patient Localization During Prostate External Beam Localization

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Y; Gardner, S; Liu, C; Zhao, B; Wen, N; Brown, S; Chetty, I [Henry Ford Health System, Detroit, MI (United States)

    2016-06-15

    Purpose: To present a novel positioning strategy which optimizes radiation delivery with radiobiological response knowledge, and to evaluate its application during prostate external beam radiotherapy. Methods: Ten patients with low or intermediate risk prostate cancer were evaluated retrospectively in this IRB-approved study. For each patient, a VMAT plan was generated on the planning CT (PCT) to deliver 78 Gy in 39 fractions with PTV = prostate + 7 mm margin, except for 5mm in the posterior direction. Five representative pretreatment CBCT images were selected for each patient, and prostate, rectum, and bladder were delineated on all CBCT images. Each CBCT was auto-registered to the corresponding PCT. Starting from this auto-matched position (AM-position), a search for optimal treatment position was performed utilizing a score function based on radiobiological and dosimetric indices (D98-DTV, NTCP-rectum, and NTCP-bladder) for the daily target volume (DTV), rectum, and bladder. DTV was defined as prostate + 4 mm margin to account for intra-fraction motion as well as contouring variability on CBCT. We termed the optimal treatment position the radiobiologically optimized couch shift position (ROCS-position). Results: The indices, averaged over the 10 patients’ treatment plans, were (mean±SD): 77.7±0.2 Gy (D98-PTV), 12.3±2.7% (NTCP-rectum), and 53.2±11.2% (NTCP-bladder). The corresponding values calculated on all 50 CBCT images at the AM-positions were 72.9±11.3 Gy (D98-DTV), 15.8±6.4% (NTCP-rectum), and 53.0±21.1% (NTCP-bladder), respectively. In comparison, calculated on CBCT at the ROCS-positions, the indices were 77.0±2.1 Gy (D98-DTV), 12.1±5.7% (NTCP-rectum), and 60.7±16.4% (NTCP-bladder). Compared to autoregistration, ROCS-optimization recovered dose coverage to target volume and lowered the risk to rectum. Moreover, NTCPrectum for one patient remained high after ROCS-optimization and therefore could potentially benefit from adaptive planning

  11. SU-E-T-571: Newly Emerging Integrated Transmission Detector Systems Provide Online Quality Assurance of External Beam Radiation Therapy

    International Nuclear Information System (INIS)

    Hoffman, D; Chung, E; Hess, C; Stern, R; Benedict, S

    2015-01-01

    Purpose: Two newly emerging transmission detectors positioned upstream from the patient have been evaluated for online quality assurance of external beam radiotherapy. The prototype for the Integral Quality Monitor (IQM), developed by iRT Systems GmbH (Koblenz, Germany) is a large-area ion chamber mounted on the linac accessory tray to monitor photon fluence, energy, beam shape, and gantry position during treatment. The ion chamber utilizes a thickness gradient which records variable response dependent on beam position. The prototype of Delta4 Discover™, developed by ScandiDos (Uppsala, Sweden) is a linac accessory tray mounted 4040 diode array that measures photon fluence during patient treatment. Both systems are employable for patient specific QA prior to treatment delivery. Methods: Our institution evaluated the reproducibility of measurements using various beam types, including VMAT treatment plans with both the IQM ion chamber and the Delta4 Discover diode array. Additionally, the IQM’s effect on photon fluence, dose response, simulated beam error detection, and the accuracy of the integrated barometer, thermometer, and inclinometer were characterized. The evaluated photon beam errors are based on the annual tolerances specified in AAPM TG-142. Results: Repeated VMAT treatments were measured with 0.16% reproducibility by the IQM and 0.55% reproducibility by the Delta4 Discover. The IQM attenuated 6, 10, and 15 MV photon beams by 5.43±0.02%, 4.60±0.02%, and 4.21±0.03% respectively. Photon beam profiles were affected <1.5% in the non-penumbra regions. The IQM’s ion chamber’s dose response was linear and the thermometer, barometer, and inclinometer agreed with other calibrated devices. The device detected variations in monitor units delivered (1%), field position (3mm), single MLC leaf positions (13mm), and photon energy. Conclusion: We have characterized two new transmissions detector systems designed to provide in-vivo like measurements upstream

  12. SU-E-T-571: Newly Emerging Integrated Transmission Detector Systems Provide Online Quality Assurance of External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D; Chung, E; Hess, C; Stern, R; Benedict, S [UC Davis Cancer Center, Sacramento, CA (United States)

    2015-06-15

    Purpose: Two newly emerging transmission detectors positioned upstream from the patient have been evaluated for online quality assurance of external beam radiotherapy. The prototype for the Integral Quality Monitor (IQM), developed by iRT Systems GmbH (Koblenz, Germany) is a large-area ion chamber mounted on the linac accessory tray to monitor photon fluence, energy, beam shape, and gantry position during treatment. The ion chamber utilizes a thickness gradient which records variable response dependent on beam position. The prototype of Delta4 Discover™, developed by ScandiDos (Uppsala, Sweden) is a linac accessory tray mounted 4040 diode array that measures photon fluence during patient treatment. Both systems are employable for patient specific QA prior to treatment delivery. Methods: Our institution evaluated the reproducibility of measurements using various beam types, including VMAT treatment plans with both the IQM ion chamber and the Delta4 Discover diode array. Additionally, the IQM’s effect on photon fluence, dose response, simulated beam error detection, and the accuracy of the integrated barometer, thermometer, and inclinometer were characterized. The evaluated photon beam errors are based on the annual tolerances specified in AAPM TG-142. Results: Repeated VMAT treatments were measured with 0.16% reproducibility by the IQM and 0.55% reproducibility by the Delta4 Discover. The IQM attenuated 6, 10, and 15 MV photon beams by 5.43±0.02%, 4.60±0.02%, and 4.21±0.03% respectively. Photon beam profiles were affected <1.5% in the non-penumbra regions. The IQM’s ion chamber’s dose response was linear and the thermometer, barometer, and inclinometer agreed with other calibrated devices. The device detected variations in monitor units delivered (1%), field position (3mm), single MLC leaf positions (13mm), and photon energy. Conclusion: We have characterized two new transmissions detector systems designed to provide in-vivo like measurements upstream

  13. Strengthening of structurally damaged wide shallow RC beams using externally bonded CFRP plates

    Directory of Open Access Journals (Sweden)

    Rajeh A. Al-Zaid

    Full Text Available Reinforced concrete wide shallow beams (WSBs are commonly used in the joist flooring systems. The structural behavior of WSBs strengthened with carbon fiber reinforced polymer (CFRP reinforcement was studied on isolated beams and as part of full-scale building. The effect of structural damage on the performance of WSBs flexurally strengthened with CFRP plates was investigated and presented in this paper. Eight full-scale WSBs were tested under four-point bending up to failure. Seven beams were strengthened with CFRP plates bonded to the soffit of the beams and one beam was unstrengthened serving as control. Prior to strengthening, the beams were subjected to different levels of damaging by preloading to 30-95% of the beams' flexural capacity. One beam was fully damaged by preloading to failure and repaired before strengthening by replacing the crushed concrete. The data showed that the pre-damaged strengthened beams exhibited ultimate capacities up to 8% lower than those of the undamaged strengthened beams. However, the load carrying capacities of pre-damaged strengthened beams were more than those predicted by ACI 440 design guide, fib Bulletin 14, and JSCE design recommendations. Both fib Bulletin 14 and JSCE design recommendations gave very conservative predictions with average ratios of experimental to predicted ultimate capacity of 2.02 and 2.35, respectively. More accurate predictions were obtained by ACI 440 design guide as the corresponding ratio was 1.24. These results indicate that strong confidence and reliability can be placed in applying CFRP strengthening to structurally damaged WSBs.

  14. Spill control and intensity monitoring for the Bevatron--Bevalac external particle beams

    International Nuclear Information System (INIS)

    Barale, J.J.; Crebbin, K.C.

    1975-03-01

    Time-intensity modulation in beam spill can be of primary concern in some experiments. The major source of this beam structure is from main-guide field-magnet power supply ripple. If the time constants are appropriate, then final control of beam structure can be accomplished by closed loop control of the intensity of beam spill. The response characteristics of the feedback system will determine the final structure. At high beam fluxes signal to noise ratio of beam detectors, in the feedback loop, can be improved by at least four orders of magnitude by using photomultiplier tubes and a water Cherenkov counter in place of the normal secondary emission monitor. At beam fluxes below 10 10 particles per second (PPS), a plastic scintillator and photomultiplier tube are used in the feedback system. A plastic scintillator and photomultiplier are also used in the beam as intensity monitors. At intensities below about 10 7 PPS standard counting techniques are used. For intensities between 10 6 to 110 9 PPS, the photomultiplier is used as a current source driving an integrating circuit which is then calibrated to read the number of particles per pulse. (U.S.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

    Calvo, Felipe A.; Sole, Claudio V.; Cambeiro, Mauricio; Montero, Angel; Polo, Alfredo; Gonzalez, Carmen; Cuervo, Miguel; San Julian, Mikel

    2014-01-01

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

  17. A new small-footprint external-beam PIXE facility for cultural heritage applications using pulsed proton beams

    Science.gov (United States)

    Vadrucci, M.; Bazzano, G.; Borgognoni, F.; Chiari, M.; Mazzinghi, A.; Picardi, L.; Ronsivalle, C.; Ruberto, C.; Taccetti, F.

    2017-09-01

    In the framework of the COBRA project, elemental analyses of cultural heritage objects based on the particle induced X-ray emission (PIXE) are planned in a collaboration between the APAM laboratory of ENEA-Frascati and the LABEC laboratory of INFN in Florence. With this aim a 3-7 MeV pulsed proton beam, driven by the injector of the protontherapy accelerator under construction for the TOP-IMPLART project, will be used to demonstrate the feasibility of the technique with a small-footprint pulsed accelerator to Italian small and medium enterprises interested in the composition analysis of ancient artifacts. The experimental set-up for PIXE analysis on the TOP-IMPLART machine consists of a modified assembly of the vertical beam line usually dedicated to radiobiology experiments: the beam produced by the injector (RFQ + DTL, a PL7 ACCSYSHITACHI model) is bent to 90° by a magnet, is collimated by a 300 μm aperture inserted in the end nozzle and extracted into ambient pressure by an exit window consisting of a Upilex foil 7.5 μm thick. The beam is pulsed with a variable pulse duration of 20-100 μs and a repetition rate variable from 10 to 100 Hz. The X-ray detection system is based on a Ketek Silicon Drift Detector (SDD) with 7 mm2 active area and 450 μm thickness, with a thin Beryllium entrance window (8 μm). The results of the calibration of this new PIXE set-up using thick target standards and of the analysis of the preliminary measurements on pigments are presented.

  18. The effect of combined external beam and high-dose intracavitary brachytherapy on dysphagia and survival in patients with advanced esophageal cancer

    International Nuclear Information System (INIS)

    Yorozu, Atsunori; Dokiya, Takushi; Ogita, Mikio; Kutsuki, Shoji

    1996-01-01

    During an 11-year period, a group of 130 patients with esophageal cancer of stages 2 to 4 were treated with external beam irradiation (40 to 60 Gy) followed by boost dose of 10 to 20 Gy of high-dose intracavitary brachytherapy. The overall 2-year survival rate was 15.4%. The significant prognostic factors were tumor size, response to external beam irradiation, pretreatment dysphagia score, and presence of distant metastases. The palliative effect was excellent; the dysphagia scores of 122 of 130 patients (93.8%) improved. The significant palliative factors were response to external beam irradiation and pretreatment dysphagia score. Tracheoesophageal fistulas developed after treatment in 13 of 130 patients (10%); 3 of the fistulas were probably related to radiotherapy. We conclude that intracavitary brachytherapy is useful in the treatment of cases of advanced cancer which show a good response to external beam irradiation and may be curative in patients with mild dysphagia. (author)

  19. Influence of boost technique (external beam radiotherapy or brachytherapy) on the outcome of patients with carcinoma of the base of the tongue

    International Nuclear Information System (INIS)

    Regueiro, C.A.; Millan, I.; Torre, A. de la; Valcarcel, F.J.; Magallon, R.; Fernandez, E.; Aragon, G.

    1995-01-01

    We reviewed 90 patients with squamous cell carcinoma of the base of the tongue. Fifty-three patients were treated with external beam radiotherapy alone (3 T1, 11 T2, 21 T3, and 18 T4 tumors) and thirty-seven patients were treated with external beam radiotherapy plus brachytherapy boost (4 T1, 15 T2, 11 T3, and 7 T4 tumors). For patients with T1, T2 and T3 primaries, the actuarial 3-year local relapse-free survival was 42% following external beam radiotherapy alone and 67% following external beam radiotherapy plus brachytherapy (p<0.05). The actuarial 3-year cause specific survival for these T-stages was 37% for patients treated with external beam radiotherapy alone and 53% for patients treated with external beam radiotherapy plus brachytherapy (p=0.1). In the Cox multivariate analyses restricted patients with T1, T2 and T3 staged tumors, treatment modality was the only predictor for local control but no influence on specific survival was found. The trend towards significant differences in specific survival found in the univariate comparison of both treatment modalities was probably due to the significantly higher number of N-positive patients treated with external beam radiotherapy alone. When all stages were included in the Cox analysis, low hemoglobin level, invasion of deep muscle, number of palpable nodes, and history of weight loss significantly influenced the outcome. Soft tissue necrosis occurred more frequently in patients treated with external beam radiotherapy plus brachytherapy (33% vs. 10%, p=0.52). (orig.)

  20. Comparison between radioimmunotherapy and external beam radiation therapy for patients with hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Zhao-Chong [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, 136 Yi Xue Yuan Road, Shanghai, 200032 (China); Tang, Zhao-You; Yang, Bing-Hui; Liu, Kang-Da; Wu, Zhi-Quan; Fan, Jia; Qin, Lun-Xiu; Sun, Hui-Chuan; Zhou, Jian [Liver Cancer Institute, Fudan University, Shanghai (China); Jiang, Guo-Liang [Department of Radiation Oncology, Cancer Hospital. Fudan University, Shanghai (China)

    2002-12-01

    It has previously been observed in animal studies that, at equivalent doses, radioimmunotherapy (RIT) is 2.5 times more effective than multiple fractions of external beam radiation therapy (EBRT) in inhibiting tumour growth. In this study, we compared the use of RIT and EBRT in patients with hepatocellular carcinoma (HCC), treated during the past 10 years. Of 67 patients without extrahepatic involvement, 32 were treated with hepatic artery ligation combined with RIT (the RIT group) while 35 were treated with a combination of hepatic arterial chemo-embolisation and EBRT (the EBRT group). The patients in the RIT group received {sup 131}I-Hepama-1 monoclonal antibody, which was infused through the hepatic artery catheter. The patients in the EBRT group received transcatheter arterial chemo-embolisation and limited-field EBRT using a linear accelerator. Parameters observed include tumour response, alpha-fetoprotein (AFP) level in serum, human anti-murine antibody (HAMA) assay, T lymphocyte subsets, survival rates, routine parameters, sequential resection rates and histopathological status of the resection specimens. The sequential resection rates were 53% (17/32) and 23% (8/35), and tumour response rates were 72% (23/32) and 86% (30/35) in the RIT and EBRT groups, respectively. The main side-effects in the RIT group were mild allergic reactions. The most common toxicity in the EBRT group was an increase in liver enzymes. The liver tissue in the target volume was injured by EBRT. The injured liver tissue revealed a low-attenuation area adjacent to the hepatic tumour within the target volume on follow-up computed tomography studies after EBRT. On pathological evaluation, the low-attenuation area revealed hyperaemia, distended hepatic sinusoids packed with erythrocytes and hepatic cell loss. The sequential resection specimens from both the RIT and the EBRT group showed residual cancer tissue located at the edge of the mass. The residual cancer cells presented as giant

  1. TH-A-BRC-00: New Task Groups for External Beam QA: An Overview

    International Nuclear Information System (INIS)

    2016-01-01

    of possible dosimetry protocols. The report will be reviewed by the AAPM Working Group on Recommendations for Radiotherapy External Beam Quality Assurance and then by the AAPM Science Council before publication in Medical Physics Survey of possible calibration protocols for calibration of Gamma Stereotactic Radiosurgery (GSR) devices Overview of modern Quality Assurance techniques for GSR AAPM TG-218 Tolerance Levels and Methodologies for IMRT Verification QA - Moyed Miften Patient-specific IMRT QA measurement is a process designed to identify discrepancies between calculated and delivered doses. Error tolerance limits are not well-defined or consistently applied across centers. The AAPM TG-218 report has been prepared to improve the understanding and consistency of this process by providing recommendations for methodologies and tolerance limits in patient-specific IMRT QA. Learning Objectives: Review measurement methods and methodologies for absolute dose verification Provide recommendations on delivery methods, data interpretation, the use of analysis routines and choice of tolerance limits for IMRT QA Sonja Dieterich has a research agreement with Sun Nuclear Inc. Steven Goetsch is a part-time consultant for Elekta.

  2. Conformal Brachytherapy Boost To External Beam Irradiation For Clinically Localized High Risk Prostate Cancer

    International Nuclear Information System (INIS)

    Dattoli, Michael J.; Wasserman, Stuart G.; Koval, John M.; Sorace, Richard A.; Cash, Jennifer; Wallner, Kent E.

    1995-01-01

    Purpose: To evaluate the efficacy of using a Pd-103 implant as a boost in conjunction with external beam radiotherapy (EBRT) in patients having prostate cancer associated with adverse features. Materials and Methods: 114 consecutive high risk patients have been treated with combination EBRT and Pd-103 implant. 70 patients with follow-up range of 12-42 months (median 24 months) form the basis of this report. Each patient had at least one of the following risk factors for extra-capsular disease extension: Stage T2b or greater ((66(70))), Gleason score ≥ 7 ((38(70))), significantly elevated PSA (typically > 15 ng/ml)((30(70))) or elevated serum prostatic acid phosphatase (SPAP)((17(70))). Patients received median 4140 cGy EBRT to a limited pelvic field followed by a Pd-103 boost (median prescription dose: 8000 cGy). All patients have been followed in a prospective fashion with respect to PSA response, clinical evidence of disease progression and complications. Criteria for biochemical failure was relatively strict, and was analyzed using both, PSA > 2.0 and PSA > 1.0 as end points. Patients whose PSA was still decreasing at last follow-up were censored at that time. Freedom from failure rates were calculated by the method of Kaplan and Meier. Differences between groups were determined by the Log-rank method. Sexual potency was defined as the ability to attain and maintain an erection sufficient for intercourse. Results: Actuarial freedom from biochemical failure at 3 years after treatment was 90% and 78%, when PSA > 2 and PSA > 1 were used, respectively. There are no documented local relapses. 4 patients failed distantly, and all other failures are based solely on rising PSA values. Biochemical failure was higher in patients having Gleason score ≥ 7 (p=0.001), those with PSA >20 (p=0.014) and in those with elevated SPAP (p=0.007). The primary treatment related morbity was temporary, Grade 1-2 urinary symptoms. No patient developed rectal ulceration or prostatic

  3. Conformal Brachytherapy Boost To External Beam Irradiation For Clinically Localized High Risk Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Dattoli, Michael J; Wasserman, Stuart G; Koval, John M; Sorace, Richard A; Cash, Jennifer; Wallner, Kent E

    1995-07-01

    Purpose: To evaluate the efficacy of using a Pd-103 implant as a boost in conjunction with external beam radiotherapy (EBRT) in patients having prostate cancer associated with adverse features. Materials and Methods: 114 consecutive high risk patients have been treated with combination EBRT and Pd-103 implant. 70 patients with follow-up range of 12-42 months (median 24 months) form the basis of this report. Each patient had at least one of the following risk factors for extra-capsular disease extension: Stage T2b or greater ((66(70))), Gleason score {>=} 7 ((38(70))), significantly elevated PSA (typically > 15 ng/ml)((30(70))) or elevated serum prostatic acid phosphatase (SPAP)((17(70))). Patients received median 4140 cGy EBRT to a limited pelvic field followed by a Pd-103 boost (median prescription dose: 8000 cGy). All patients have been followed in a prospective fashion with respect to PSA response, clinical evidence of disease progression and complications. Criteria for biochemical failure was relatively strict, and was analyzed using both, PSA > 2.0 and PSA > 1.0 as end points. Patients whose PSA was still decreasing at last follow-up were censored at that time. Freedom from failure rates were calculated by the method of Kaplan and Meier. Differences between groups were determined by the Log-rank method. Sexual potency was defined as the ability to attain and maintain an erection sufficient for intercourse. Results: Actuarial freedom from biochemical failure at 3 years after treatment was 90% and 78%, when PSA > 2 and PSA > 1 were used, respectively. There are no documented local relapses. 4 patients failed distantly, and all other failures are based solely on rising PSA values. Biochemical failure was higher in patients having Gleason score {>=} 7 (p=0.001), those with PSA >20 (p=0.014) and in those with elevated SPAP (p=0.007). The primary treatment related morbity was temporary, Grade 1-2 urinary symptoms. No patient developed rectal ulceration or prostatic

  4. TH-A-BRC-00: New Task Groups for External Beam QA: An Overview

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    of possible dosimetry protocols. The report will be reviewed by the AAPM Working Group on Recommendations for Radiotherapy External Beam Quality Assurance and then by the AAPM Science Council before publication in Medical Physics Survey of possible calibration protocols for calibration of Gamma Stereotactic Radiosurgery (GSR) devices Overview of modern Quality Assurance techniques for GSR AAPM TG-218 Tolerance Levels and Methodologies for IMRT Verification QA - Moyed Miften Patient-specific IMRT QA measurement is a process designed to identify discrepancies between calculated and delivered doses. Error tolerance limits are not well-defined or consistently applied across centers. The AAPM TG-218 report has been prepared to improve the understanding and consistency of this process by providing recommendations for methodologies and tolerance limits in patient-specific IMRT QA. Learning Objectives: Review measurement methods and methodologies for absolute dose verification Provide recommendations on delivery methods, data interpretation, the use of analysis routines and choice of tolerance limits for IMRT QA Sonja Dieterich has a research agreement with Sun Nuclear Inc. Steven Goetsch is a part-time consultant for Elekta.

  5. Organ localization in fractionated external beam radiotherapy for early stage prostatic adenocarcinoma

    International Nuclear Information System (INIS)

    Jaffray, D.A.; Horwitz, E.M.; Wong, J.W.; Martinez, A.A.; Brabbins, D.S.

    1996-01-01

    Purpose: Trends toward higher target doses and more conformal radiation field shaping place strict requirements on geometric localisation of the target and surrounding normal structures. Daily localization of these structures is not possible on a conventional treatment machine. For this reason, margins must be incorporated in the field shaping to accommodate any target or normal structure displacement. There are few studies which examine the magnitude of these displacements. We hypothesize that these uncertainties can be reduced by daily radiographic imaging of bony anatomy as an alternative to skin tattoos. This hypothesis is tested using multiple (15-19) CT scans on five patients receiving external beam radiotherapy of the prostate. Materials and Methods: Five patients were CT scanned in treatment position (with immobilization device) on every second day of their initial XRT course (non-boost). Radiopaque markers were placed on the skin tattoos to make them visible in the CT datasets. The scans were collected on a helical CT scanner (SR-7000, 3mm and 5mm slice thickness, 120kVp) and transferred to a workstation for analysis. The structures (prostate, rectum, bladder, and seminal vesicles) on all 80 CT datasets were contoured (manually) by two physicians. A reference dataset was chosen for each patient. The 3D transformations between the study datasets and the reference set were determined using an automated technique. A separate transformation was determined for the alignment of (i) bone (excluding femora) and (ii) skin marks. The contours from each dataset were then transformed back to the reference dataset. The resulting contours show the position of organ relative to either the skin marks (tattoos) or the bony anatomy. The displacement and distortion of the organs were parameterized by the displacement of the volume edge (AP, LAT, SUP-INF), volume, and center-of-mass (COM). Each calculation was performed for an individual patient. Population averages were also

  6. Feasibility and efficacy of external beam radiotherapy after hyperthermic isolated limb perfusion with TNF-α and melphalan for limb-saving treatment in locally advanced extremity soft-tissue sarcoma

    International Nuclear Information System (INIS)

    Olieman, Annette F.T.; Pras, Elisabeth; Ginkel, Robert J. van; Molenaar, Willemina M.; Koops, Heimen Schraffordt; Hoekstra, Harald J.

    1998-01-01

    Purpose: Hyperthermic isolated limb perfusion (HILP) with tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and melphalan is associated with a dramatic antitumor effect in locally advanced extremity soft-tissue sarcomas (STS). The aim of this study was to demonstrate the feasibility and efficacy of adjuvant radiotherapy after HILP with TNF-α, IFN-γ, and melphalan and delayed surgical resection. Methods and Materials: Between 1991 and 1995, 34 patients--16 males and 18 females, median age 50 (range 18-80) years--underwent HILP for locally advanced extremity STS. Resection of the residual tumor mass was performed in most patients after 6-8 weeks. Fifteen patients with histopathological viable tumor after resection received adjuvent 60-70 Gy external beam radiotherapy (EBRT) (44%, HILP + EBRT group). Nineteen patients received HILP without adjuvent EBRT (56%, HILP-only group). Five patients in the HILP-only group had also distant metastases (15%) and received HILP as a palliative treatment. Treatment morbidity, local recurrences, and regional and distant metastases were scored. Results: During a median follow-up of 34 months (range 8-54), limb salvage was achieved in 29 patients (85%): 14 patients after HILP + EBRT and 15 patients after HILP only. None of the patients from the HILP + EBRT group developed local recurrences; however, five patients from the HILP-only did (26%) (p < 0.05). Regional metastases were observed in one patient from the HILP + EBRT group (7%) and in two patients from the HILP-only group who were treated with curative intent (14%). Distant metastases occurred in four patients after HILP + EBRT (27%) and in four patients after HILP only with curative intent (29%). The mean morbidity (subjective, objective, medical management, and analytical evaluation) score in both groups was, respectively, 0.33 for skin and subcutaneous tissue and for muscle and soft tissue, 0.34 (HILP + EBRT group) and 0.33 (HILP-only group). Conclusion: Adjuvent

  7. Comprehensive MRI simulation methodology using a dedicated MRI scanner in radiation oncology for external beam radiation treatment planning

    International Nuclear Information System (INIS)

    Paulson, Eric S.; Erickson, Beth; Schultz, Chris; Allen Li, X.

    2015-01-01

    Purpose: The use of magnetic resonance imaging (MRI) in radiation oncology is expanding rapidly, and more clinics are integrating MRI into their radiation therapy workflows. However, radiation therapy presents a new set of challenges and places additional constraints on MRI compared to diagnostic radiology that, if not properly addressed, can undermine the advantages MRI offers for radiation treatment planning (RTP). The authors introduce here strategies to manage several challenges of using MRI for virtual simulation in external beam RTP. Methods: A total of 810 clinical MRI simulation exams were performed using a dedicated MRI scanner for external beam RTP of brain, breast, cervix, head and neck, liver, pancreas, prostate, and sarcoma cancers. Patients were imaged in treatment position using MRI-optimal immobilization devices. Radiofrequency (RF) coil configurations and scan protocols were optimized based on RTP constraints. Off-resonance and gradient nonlinearity-induced geometric distortions were minimized or corrected prior to using images for RTP. A multidisciplinary MRI simulation guide, along with window width and level presets, was created to standardize use of MR images during RTP. A quality assurance program was implemented to maintain accuracy and repeatability of MRI simulation exams. Results: The combination of a large bore scanner, high field strength, and circumferentially wrapped, flexible phased array RF receive coils permitted acquisition of thin slice images with high contrast-to-noise ratio (CNR) and image intensity uniformity, while simultaneously accommodating patient setup and immobilization devices. Postprocessing corrections and alternative acquisition methods were required to reduce or correct off-resonance and gradient nonlinearity induced geometric distortions. Conclusions: The methodology described herein contains practical strategies the authors have implemented through lessons learned performing clinical MRI simulation exams. In

  8. Comprehensive MRI simulation methodology using a dedicated MRI scanner in radiation oncology for external beam radiation treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, Eric S., E-mail: epaulson@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 and Department of Radiology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 (United States); Erickson, Beth; Schultz, Chris; Allen Li, X. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 (United States)

    2015-01-15

    Purpose: The use of magnetic resonance imaging (MRI) in radiation oncology is expanding rapidly, and more clinics are integrating MRI into their radiation therapy workflows. However, radiation therapy presents a new set of challenges and places additional constraints on MRI compared to diagnostic radiology that, if not properly addressed, can undermine the advantages MRI offers for radiation treatment planning (RTP). The authors introduce here strategies to manage several challenges of using MRI for virtual simulation in external beam RTP. Methods: A total of 810 clinical MRI simulation exams were performed using a dedicated MRI scanner for external beam RTP of brain, breast, cervix, head and neck, liver, pancreas, prostate, and sarcoma cancers. Patients were imaged in treatment position using MRI-optimal immobilization devices. Radiofrequency (RF) coil configurations and scan protocols were optimized based on RTP constraints. Off-resonance and gradient nonlinearity-induced geometric distortions were minimized or corrected prior to using images for RTP. A multidisciplinary MRI simulation guide, along with window width and level presets, was created to standardize use of MR images during RTP. A quality assurance program was implemented to maintain accuracy and repeatability of MRI simulation exams. Results: The combination of a large bore scanner, high field strength, and circumferentially wrapped, flexible phased array RF receive coils permitted acquisition of thin slice images with high contrast-to-noise ratio (CNR) and image intensity uniformity, while simultaneously accommodating patient setup and immobilization devices. Postprocessing corrections and alternative acquisition methods were required to reduce or correct off-resonance and gradient nonlinearity induced geometric distortions. Conclusions: The methodology described herein contains practical strategies the authors have implemented through lessons learned performing clinical MRI simulation exams. In

  9. Numerical study of chaotic oscillations in the electron beam with virtual cathode in the external non-uniform magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Hramov, Alexander E., E-mail: aeh@nonlin.sgu.r [Faculty of Nonlinear Processes, Saratov State University, 83, Astrakhanskaya, Saratov, 410012 (Russian Federation); Koronovskii, Alexey A., E-mail: alkor@nonlin.sgu.r [Faculty of Nonlinear Processes, Saratov State University, 83, Astrakhanskaya, Saratov, 410012 (Russian Federation); Kurkin, Semen, E-mail: KurkinSA@nonlin.sgu.r [Faculty of Nonlinear Processes, Saratov State University, 83, Astrakhanskaya, Saratov, 410012 (Russian Federation)

    2010-07-05

    In this Letter the results of theoretical investigations of the chaotic microwave oscillator based on the electron beam with a virtual cathode are presented. Nonlinear non-stationary processes in these electron systems are studied by means of numerical analysis of 2.5D model. It was discovered that the non-uniform external magnetic field value controls the dynamical regime of oscillations in the virtual cathode oscillator. The processes of the chaotization of output microwave radiation are described and interpreted from the point of view of the formation and interaction of electron structures (bunches) in the electron beams. The numerical results have shown that the investigated electron system with virtual cathode could be considered as a promising controlled source of wideband chaotic oscillations in the microwave range.

  10. Study on the proton-induced X-ray emission(PIXE) using external proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, M. Y.; Yoon, J. C.; Park, K. J. [Seoul Natioanl University, Seoul (Korea, Republic of)

    2008-04-15

    We intend to develop a system that can extract a proton beam into air for a qualitative, and quantitative PIXE analysis up to ppm(percent per million) composition. When such an R and D is accomplished, first it is possible to get equipped with a system for PIXE and PIGmE, second, it is possible to contribute to an academic progress by the study for physical properties of matter through an nuclear science methods when the comparison between the measurement and the calculated quantities, and third, it is possible to contribute to a multi-disciplinary researches by the measurements of the samples for which it is hard to get the SRM for the samples. We intend to develop methods to measure the beam current for an air-borne proton beam, and to minimize the energy and current loss of the beam. We intend to acquire a set of PIXE data for rare-earth metals and transient metals, to form a basic database for the analysis for various samples for which it is hard to get the SRM. Developed PIXE beamline can extract the beam diameter up to 5mm, and beam intensity in the range 0.5nA to 10nA variable. sustaining the vacuum better than 10{sup -6} mtorr. Necessary detection system and methodology are complete. As the application of the present research achievements, we studied the analysis of aerosol composition, the appraisal of the cultural heritages, and a feasibility study for a proton beam writing. It is expected to become possible to analyse the compositions of the gems, the elemental compositions of the food, the discrimination of the traditional ink and the modern ink on the documents, the evaluation of the documents by the analysis of the elemental composition of the stamps, The analysis of the paper with respect to the date and the quality, the analysis of the color, and the core bored samples

  11. Unresectable Retiform Hemangioendothelioma Treated with External Beam Radiation Therapy and Chemotherapy: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Alina Z. Hirsh

    2010-01-01

    Full Text Available Retiform hemangioendothelioma (RH is an infrequently encountered vascular neoplasm of intermediate or borderline malignancy. Treatment of RH is controversial. We present a case of a 44-year-old Asian male presenting with an unresectable RH of the pelvis. The patient was treated with concurrent low-dose Cisplatin and External beam Radiation (4140cGy in 180cGy per fraction. This is the first report of a clinical complete response and a long-term local control of this rare tumor. This has significant clinical implication, since it gives the first evidence of treatment of this rare tumor using concurrent low-dose chemotherapy and radiation.

  12. Locoregional recurrences following radical external beam irradiation and interstitial implantation for operable breast cancer - a twenty three year experience

    International Nuclear Information System (INIS)

    Leung, S.; Otmezguine, Y.; Calitchi, E.; Mazeron, J.J.; Le Bourgeois, J.P.; Pierquin, B.

    1986-01-01

    Locoregional recurrences are reported in 493 consecutive with T1 T2 N0 N1 breast cancer patients who were treated with radical external beam irradiation and interstitial 192 Ir implant between 1961 and 1979. Follow-up ranges from 5-23 years (mean 10 years) with 195 patients having 10-23 years follow up (mean 12 years). There were 51 (10%) locoregional recurrences with 34 mammary, 14 combined mammary/axillary and 3 isolated axillary recurrences. The 10 year relapse rate was 20/195 (10%). The results have been compared with other series in the literature and changes in the authors' current protocol are described. (Auth.)

  13. The development of an interdepartmental audit as part of a physics quality assurance programme for external beam therapy

    International Nuclear Information System (INIS)

    Bonnett, D.E.; Jaukett, R.J.; Mills, J.A.; Martin-Smith, P.

    1994-01-01

    A cost-effective audit system has been developed that will both detect systematic error in data and procedures, and evaluate the quality assurance programme provided by a physics department for radiotherapy. The audit has been developed for external beam radiotherapy and assesses one modality and one treatment machine per year. The method of assessing the quality assurance programme and the schedule of measurements are described. The process is illustrated using the results of trial audits between the medical physics department at Coventry and Leicester. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Baci, Syrja, E-mail: sbarci2013@gmail.com [Department of Physics, Faculty of Natural Sciences, University of Gjirokastra, “Eqrem Çabej” (Albania); Telhaj, Ervis [Department of Medical Physics, Hygeia Hospital Tirana (Albania); Malkaj, Partizan [Department of Physical Engineering, Polytechnic University, Tirana (Albania)

    2016-03-25

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

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

    International Nuclear Information System (INIS)

    Baci, Syrja; Telhaj, Ervis; Malkaj, Partizan

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    Sole, C.V.; Calvo, F.A.; Lozano, M.A.; Gonzalez-Sansegundo, C.; Gonzalez-Bayon, L.; Alvarez, A.; Lizarraga, S.; Garcia-Sabrido, J.L.

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-02-15

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

  19. Adjuvant radiotherapy with brachytherapy boost in soft tissue sarcomas

    Directory of Open Access Journals (Sweden)

    Annalisa Cortesi

    2017-06-01

    Full Text Available Purpose: The standard primary treatment for soft tissue sarcoma (STS is a wide surgical resection, preceded or followed by radiotherapy. Purpose of this retrospective study was to assess the efficacy of perioperative brachytherapy (BRT plus postoperative external beam radiation therapy (EBRT in patients with intermediate-high risk STS. Material and methods : BRT delivered dose was 20 Gy. External beam radiation therapy was delivered with 3D-technique using multiple beams. The prescribed dose was 46 Gy to the PTV. Neoadjuvant and adjuvant chemotherapy (CHT was used in patients with potentially chemosensitive histological subtypes. The primary aim of the study was to analyze overall survival (OS and local control (LC in a large patient population treated with surgery, perioperative BRT, and adjuvant EBRT ± CHT. Secondary objective was to identify prognostic factors for patients outcome in terms of LC, disease-free survival (DFS, and OS. Results : From 2000 to 2011, 107 patients presenting 2-3 grade (FNLCC primary or recurrent STS were treated with surgery, perioperative BRT, and adjuvant EBRT ± CHT. Five-year LC and OS were 80.9% and 87.4%, respectively. At univariate analysis, a higher LC was recorded in primary vs. recurrent tumors (p = 0.015, and in lower limb tumors vs. other sites (p = 0.027. An improved DFS was recorded in patients with lower limb tumors vs. other sites (p = 0.034. Conclusions : The combination of BRT and EBRT was able to achieve satisfactory results even in a patients population with intermediate-high risk STS. Patients with recurrent or other than lower limb sited tumors show a worse LC.

  20. Adjuvant radiotherapy with brachytherapy boost in soft tissue sarcomas

    Science.gov (United States)

    Cortesi, Annalisa; Galuppi, Andrea; Arcelli, Alessandra; Romani, Fabrizio; Mattiucci, Gian Carlo; Bianchi, Giuseppe; Ferrari, Stefano; Ferraro, Andrea; Farioli, Andrea; Gambarotti, Marco; Righi, Alberto; Macchia, Gabriella; Deodato, Francesco; Cilla, Savino; Buwenge, Milly; Valentini, Vincenzo; Morganti, Alessio Giuseppe; Donati, Davide; Cammelli, Silvia

    2017-01-01

    Purpose The standard primary treatment for soft tissue sarcoma (STS) is a wide surgical resection, preceded or followed by radiotherapy. Purpose of this retrospective study was to assess the efficacy of perioperative brachytherapy (BRT) plus postoperative external beam radiation therapy (EBRT) in patients with intermediate-high risk STS. Material and methods BRT delivered dose was 20 Gy. External beam radiation therapy was delivered with 3D-technique using multiple beams. The prescribed dose was 46 Gy to the PTV. Neoadjuvant and adjuvant chemotherapy (CHT) was used in patients with potentially chemosensitive histological subtypes. The primary aim of the study was to analyze overall survival (OS) and local control (LC) in a large patient population treated with surgery, perioperative BRT, and adjuvant EBRT ± CHT. Secondary objective was to identify prognostic factors for patients outcome in terms of LC, disease-free survival (DFS), and OS. Results From 2000 to 2011, 107 patients presenting 2-3 grade (FNLCC) primary or recurrent STS were treated with surgery, perioperative BRT, and adjuvant EBRT ± CHT. Five-year LC and OS were 80.9% and 87.4%, respectively. At univariate analysis, a higher LC was recorded in primary vs. recurrent tumors (p = 0.015), and in lower limb tumors vs. other sites (p = 0.027). An improved DFS was recorded in patients with lower limb tumors vs. other sites (p = 0.034). Conclusions The combination of BRT and EBRT was able to achieve satisfactory results even in a patients population with intermediate-high risk STS. Patients with recurrent or other than lower limb sited tumors show a worse LC. PMID:28725250

  1. Study of Italian Renaissance sculptures using an external beam nuclear microprobe

    Science.gov (United States)

    Zucchiatti, A.; Bouquillon, A.; Moignard, B.; Salomon, J.; Gaborit, J. R.

    2000-03-01

    The use of an extracted proton micro-beam for the PIXE analysis of glazes is discussed in the context of the growing interest in the creation of an analytical database on Italian Renaissance glazed terracotta sculptures. Some results concerning the frieze of an altarpiece of the Louvre museum, featuring white angels and cherubs heads, are presented.

  2. Study of Italian Renaissance sculptures using an external beam nuclear microprobe

    International Nuclear Information System (INIS)

    Zucchiatti, A.; Bouquillon, A.; Moignard, B.; Salomon, J.; Gaborit, J.R.

    2000-01-01

    The use of an extracted proton micro-beam for the PIXE analysis of glazes is discussed in the context of the growing interest in the creation of an analytical database on Italian Renaissance glazed terracotta sculptures. Some results concerning the frieze of an altarpiece of the Louvre museum, featuring white angels and cherubs heads, are presented

  3. Nonlinear finite element modeling of concrete deep beams with openings strengthened with externally-bonded composites

    International Nuclear Information System (INIS)

    Hawileh, Rami A.; El-Maaddawy, Tamer A.; Naser, Mohannad Z.

    2012-01-01

    Highlights: ► A 3D nonlinear FE model is developed of RC deep beams with web openings. ► We used cohesion elements to simulate bond. ► The developed FE model is suitable for analysis of such complex structures. -- Abstract: This paper aims to develop 3D nonlinear finite element (FE) models for reinforced concrete (RC) deep beams containing web openings and strengthened in shear with carbon fiber reinforced polymer (CFRP) composite sheets. The web openings interrupted the natural load path either fully or partially. The FE models adopted realistic materials constitutive laws that account for the nonlinear behavior of materials. In the FE models, solid elements for concrete, multi-layer shell elements for CFRP and link elements for steel reinforcement were used to simulate the physical models. Special interface elements were implemented in the FE models to simulate the interfacial bond behavior between the concrete and CFRP composites. A comparison between the FE results and experimental data published in the literature demonstrated the validity of the computational models in capturing the structural response for both unstrengthened and CFRP-strengthened deep beams with openings. The developed FE models can serve as a numerical platform for performance prediction of RC deep beams with openings strengthened in shear with CFRP composites.

  4. External beam abdominal radiotherapy in patients with seminoma stage I: field type, testicular dose, and spermatogenesis

    International Nuclear Information System (INIS)

    Jacobsen, Kari Dolven; Olsen, Dag Rune; Fossaa, Kristian; Fossaa, Sophie Dorothea

    1997-01-01

    Purpose: To establish a predictive model for the estimation of the gonadal dose during adjuvant para-aortic (PA) or dog leg (DL: PA plus ipsilateral iliac) field radiotherapy in patients with testicular seminoma. Methods and Materials: The surface gonadal dose was measured in patients with seminoma Stage I receiving PA or DL radiotherapy. Sperm cell analysis was performed before and 1 year after irradiation. PA and DL radiotherapy were simulated in the Alderson phantom while we measured the dose to the surface and middle of an artificial testicle, varying its position within realistic anatomical constraints. The symphysis-to-testicle distance (STD), field length, and thickness of the patient were experimental variables. The developed mathematical model was validated in subsequent patients. Results: The mean gonadal dose in patients was 0.09 and 0.32 Gy after PA and DL irradiation, respectively (p < 0.001). DL radiotherapy, but not PA irradiation led to significant reduction of the sperm count 1 year after irradiation. The gonadal dose-reducing effect of PA irradiation was confirmed in the Alderson phantom. A significant correlation was found between the STD and the gonadal dose during DL irradiation. A mathematical model was established for calculation of the gonadal dose and confirmed by measurements in patients. Conclusions: During radiotherapy of seminoma, the gonadal dose decreases with increasing STD. It is possible to predict the individual gonadal dose based on delivered midplane dose and STD

  5. Leaflet manual of external beam radiation therapy for hepatocellular carcinoma: a review of the indications, evidences, and clinical trials

    Directory of Open Access Journals (Sweden)

    Rim CH

    2018-05-01

    Full Text Available Chai Hong Rim, Won Sup Yoon Department of Radiation Oncology, Ansan Hospital, Korea University Medical College, Ansan, Republic of Korea Abstract: The use of external beam radiation therapy (EBRT in the treatment of hepatocellular carcinoma (HCC, which was rarely performed due to liver toxicity with a previous technique, has increased. Palliation of portal vein thrombosis, supplementation for insufficient transarterial chemoembolization, and provision of new curative opportunities using stereotactic body radiotherapy are the potential indications for use of EBRT. The mechanism of EBRT treatment, with its radiobiological and physical perspectives, differs from those of conventional medical treatment or surgery. Therefore, understanding the effects of EBRT may be unfamiliar to physicians other than radiation oncologists, especially in the field of HCC, where EBRT has recently begun to be applied. The first objective of this review was to concisely explain the indications for use of EBRT for HCC for all physicians treating HCC. Therefore, this review focuses on the therapeutic outcomes rather than the detailed biological and physical background. We also reviewed recent clinical trials that may extend the indications for use of EBRT. Finally, we reviewed the current clinical practice guidelines for the treatment of HCC and discuss the current recommendations and future perspectives. Keywords: hepatocellular carcinoma, liver neoplasm, external beam radiotherapy, stereotactic body radiotherapy, clinical trials, sorafenib, guidelines

  6. A Phase II study of external-beam radiotherapy and endovascular brachytherapy with PTA and stenting for femoropopliteal artery restenosis

    International Nuclear Information System (INIS)

    Narayan, Kailash; Denton, Michael; Das, Ram; Bernshaw, David; Rolfo, Aldo; Dyk, Sylvia van; Mirakian, Alex

    2006-01-01

    Purpose: To assess the safety and seek evidence of efficacy of combined external-beam radiotherapy (EBRT) and endovascular brachytherapy in the treatment of stenotic vascular lesions. Methods and Materials: Seventeen patients with high risk for restenosis of femoropopliteal arteries were enrolled in this study from February 2000 to August 2002. The external beam radiotherapy regimen consisted of 10 Gy in 5 fractions of 2 Gy, starting on Day 0. This was followed on Day 6 by angiography, stent placement, and intraluminal brachytherapy to a dose of 10 Gy at 1.2 mm from stent surface. The EBRT was continued from the same day to another 10 Gy in 2 Gy daily fractions for 5 days. Results: The follow up ranged from 33 months to 60 months. At the time of analysis 15 of 17 patients were alive with patent stents. Of these, 10 were symptom-free. Two patients died of unrelated causes. Conclusions: The combination of EBRT and endovascular brachytherapy provided adequate dose distribution without any geographical miss or 'candy wrapper' restenosis. No incidence of aneurysmal dilation of radiated vascular segment was observed. The treatment was feasible, well tolerated, and achieved 88% stenosis free survival

  7. Complete response in a patient with gynecological hidradenocarcinoma treated with exclusive external beam radiotherapy and brachytherapy: a case report.

    Science.gov (United States)

    Giannelli, Flavio; Chiola, Ilaria; Belgioia, Liliana; Garelli, Stefania; Pastorino, Alice; Marcenaro, Michela; Mammoliti, Serafina; Costantini, Sergio; Bizzarri, Nicolò; Vellone, Valerio; Barra, Salvina; Corvò, Renzo

    2017-12-01

    Hidradenocarcinoma (HC) is a very rare disease. This case report illustrates a successful treatment of a 60-year-old woman with vulvo-vaginal localization of hidradenocarcinoma treated with external beam radiotherapy delivered by helical tomotherapy with a simultaneous integrated boost (SIB), followed by brachytherapy. External beam radiotherapy dose prescription was 50.4 Gy in 28 fractions, five fractions per week to whole pelvis (planning target volume 1 - PTV1), 60.2 Gy in 28 fractions to SIB1 (fundus of uterus and right inguinal node), and 58.8 Gy in 28 fractions to SIB2 (lower/middle third of vagina, paraurethral region and right inguinal lymph nodes). Brachytherapy dose prescription was 28 Gy in 4 fractions for cervix, fundus of uterus and upper third of vagina (HR-CTV1), and 22 Gy in 4 fractions to middle third of vagina and paraurethral region (HR-CTV2). D 90 for whole treatment was 91.9 Gy and 86.0 Gy for HR-CTV1 and HR-CTV2, respectively. Patient remained 12-months disease-free without treatment related side effects.

  8. Complete response in a patient with gynecological hidradenocarcinoma treated with exclusive external beam radiotherapy and brachytherapy: a case report

    Directory of Open Access Journals (Sweden)

    Flavio Giannelli

    2017-12-01

    Full Text Available Hidradenocarcinoma (HC is a very rare disease. This case report illustrates a successful treatment of a 60-year-old woman with vulvo-vaginal localization of hidradenocarcinoma treated with external beam radiotherapy delivered by helical tomotherapy with a simultaneous integrated boost (SIB, followed by brachytherapy. External beam radiotherapy dose prescription was 50.4 Gy in 28 fractions, five fractions per week to whole pelvis (planning target volume 1 – PTV1, 60.2 Gy in 28 fractions to SIB1 (fundus of uterus and right inguinal node, and 58.8 Gy in 28 fractions to SIB2 (lower/middle third of vagina, paraurethral region and right inguinal lymph nodes. Brachytherapy dose prescription was 28 Gy in 4 fractions for cervix, fundus of uterus and upper third of vagina (HR-CTV1, and 22 Gy in 4 fractions to middle third of vagina and paraurethral region (HR-CTV2. D90 for whole treatment was 91.9 Gy and 86.0 Gy for HR-CTV1 and HR-CTV2, respectively. Patient remained 12-months disease-free without treatment related side effects.

  9. Numerical simulation on the energy spectrum of the electron beam generated by low-impedance diode and the influence of external magnetic field on diode impedance

    International Nuclear Information System (INIS)

    Liu Guozhi

    2003-01-01

    The energy spectrum of the electron beam generated by low-impedance diode and the influence of external magnetic field on the impedance of diode are studied numerically in this paper. The results show that the beam generated by the diode has an energy spread, even with constant applied voltage. Additionally, external magnetic field has great but reverse influence on the impedance of low-impedance diode, which is, according to the author's analysis, the result of the change of the electron's track due to external magnetic field. If the beam current is less than the critical one for self-pinch, the impedance will be constant with the variation of external magnetic field

  10. SU-E-J-181: Effect of Prostate Motion On Combined Brachytherapy and External Beam Dose Based On Daily Motion of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Narayana, V; McLaughlin, P [Providence Cancer Center, Southfield, MI (United States); University of Michigan, Ann Arbor, MI (United States); Ealbaj, J [University of Michigan, Ann Arbor, MI (United States)

    2015-06-15

    Purpose: In this study, the adequacy of target expansions on the combined external beam and implant dose was examined based on the measured daily motion of the prostate. Methods: Thirty patients received an I–125 prostate implant prescribed to dose of 90Gy. This was followed by external beam to deliver a dose of 90Gyeq (external beam equivalent) to the prostate over 25 to 30 fractions. An ideal IMRT plan was developed by optimizing the external beam dose based on the delivered implant dose. The implant dose was converted to an equivalent external beam dose using the linear quadratic model. Patients were set up on the treatment table by daily orthogonal imaging and aligning the marker seeds in the prostate. Orthogonal images were obtained at the end of treatment to assess prostate intrafraction motion. Based on the observed motion of the markers between the initial and final images, 5 individual plans showing the actual dose delivered to the patient were calculated. A final true dose distribution was established based on summing the implant dose and the 5 external beam plans. Dose to the prostate, seminal vesicles, lymphnodes and normal tissues, rectal wall, urethra and lower sphincter were calculated and compared to ideal. On 18 patients who were sexually active, dose to the corpus cavernosum and internal pudendal artery was also calculated. Results: The average prostate motion in 3 orthogonal directions was less than 1 mm with a standard deviation of less than +2 mm. Dose and volume parameters showed that there was no decrease in dose to the targets and a marginal decrease in dose to in normal tissues. Conclusion: Dose delivered by seed implant moves with the prostate, decreasing the impact of intrafractions dose movement on actual dose delivered. Combined brachytherapy and external beam dose delivered to the prostate was not sensitive to prostate motion.

  11. Noninvasive referencing of intraocular tumors for external beam radiation therapy using optical coherence tomography: A proof of concept

    International Nuclear Information System (INIS)

    Rüegsegger, Michael B.; Steiner, Patrick; Kowal, Jens H.; Geiser, Dominik; Pica, Alessia; Aebersold, Daniel M.

    2014-01-01

    Purpose: External beam radiation therapy is currently considered the most common treatment modality for intraocular tumors. Localization of the tumor and efficient compensation of tumor misalignment with respect to the radiation beam are crucial. According to the state of the art procedure, localization of the target volume is indirectly performed by the invasive surgical implantation of radiopaque clips or is limited to positioning the head using stereoscopic radiographies. This work represents a proof-of-concept for direct and noninvasive tumor referencing based on anterior eye topography acquired using optical coherence tomography (OCT). Methods: A prototype of a head-mounted device has been developed for automatic monitoring of tumor position and orientation in the isocentric reference frame for LINAC based treatment of intraocular tumors. Noninvasive tumor referencing is performed with six degrees of freedom based on anterior eye topography acquired using OCT and registration of a statistical eye model. The proposed prototype was tested based on enucleated pig eyes and registration accuracy was measured by comparison of the resulting transformation with tilt and torsion angles manually induced using a custom-made test bench. Results: Validation based on 12 enucleated pig eyes revealed an overall average registration error of 0.26 ± 0.08° in 87 ± 0.7 ms for tilting and 0.52 ± 0.03° in 94 ± 1.4 ms for torsion. Furthermore, dependency of sampling density on mean registration error was quantitatively assessed. Conclusions: The tumor referencing method presented in combination with the statistical eye model introduced in the past has the potential to enable noninvasive treatment and may improve quality, efficacy, and flexibility of external beam radiotherapy of intraocular tumors

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  13. Effects of external environments on the short beam shear strength of filament wound graphite/epoxy

    Science.gov (United States)

    Penn, B. G.; Clemons, J. M.

    1986-01-01

    Filament wound graphite/epoxy samples were immersed in seawater, deionized water, and toluene at room temperature and 80 deg C for 5, 15, and 43 days, and in methanol at room temperature for 15 and 43 days. The percent weight gains and short beam shear strengths were determined after environmental exposure. Samples immersed in deionized water and seawater had higher percent weight gains than those immersed in toluene at room temperature and 80 deg C. The percent weight gains for samples immersed in methanol at room temperature were comparable to those of deionized water and seawater immersed samples. A comparison of percent decreases in short beam shear strengths could not be made due to a large scatter in data. This may indicate defects in samples due to machining or variations in material properties due to processing.

  14. Commissioning and quality assurances of the CMS XIO radiotherapy treatment planning system for external beam photons

    International Nuclear Information System (INIS)

    Muralidhar, K.R.; Anurupa; Soubhagya; Sudhakar; Shiva; Krishnam Raju, A.; Narayana Murthy, P.

    2008-01-01

    The commissioning of XIO treatment planning system (TPS) was carried out by Computerized Medical Devices, USA for Siemens and Elekta linear accelerators. The Commissioning and quality assurance of the CMS XIO radiotherapy treatment planning system involves many steps, beginning from beam data acquisition and entry into the computerized TPS, through patient data acquisition, to treatment plan generation and the final transfer of data to the treatment machine and quality assurance of TPS

  15. Computer simulation model of reflex e-beam systems coupled to an external circuit

    International Nuclear Information System (INIS)

    Jungwirth, K.; Stavinoha, P.

    1982-01-01

    Dynamics of ions and relativistic electrons in various high-voltage reflexing systems (reflex diodes and triodes) was investigated numerically by means of 1 1/2-dimensional PIC simulation model OREBIA. Its perfected version OREBIA-REX also accounts for system coupling to an external power source circuit, thus yielding the currents and applied voltage self-consistently. Various modes of operation of reflex diode and triode were studied using both models. It is shown that neglecting the influence of the external circuit can lead to seve--re overestimation of both ion currents and electron accumulation rates. In coupled systems with ions repeated collapses of impedance due to electron-ion relaxation processes are observed. The current and voltage pulses calculated for several reflex diodes and triodes with and without ions are presented. (J.U.)

  16. The correlation of PSA nadir and biochemical freedom from cancer after external beam treatment: effects of stage, grade and pretreatment PSA groupings

    International Nuclear Information System (INIS)

    Pinover, W.H.; Hanlon, A.L.; Lee, W.R.; Hanks, G.E.

    1996-01-01

    -19.9, and ≥ 20, respectively (p=0.001). A favorable PSA nadir is obtained in 72% and 51% of patients with palpation stage T1,2AB and T2C,3,4 respectively (p=0.001). A favorable PSA nadir is obtained in 71% and 63% of patients with Gleason score 2-4 and 5-7, respectively (p=NS). MVA demonstrates prerx PSA (p=0.0001) and dose (p=0.02) to be independent predictors of PSA nadir response <1.0 ng/ml. MVA also demonstrates PSA nadir (p<0.0001), dose (p=0.02), and stage (p=0.02) to be independent predictors of 5 year bNED survival. Conclusions: (1) Following external beam radiotherapy, the level of PSA nadir is the most significant predictor of bNED survival. (2) Patients achieving a PSA nadir <1.0 ng/ml have a favorable overall bNED survival rate. This is true for all patients, independent of prerx. PSA, palpation stage and Gleason score. (3) Prerx PSA and dose are predictive of PSA nadir. (4) Patients not achieving a PSA nadir <1.0 ng/ml may be candidates for early adjuvant therapy trials

  17. Skin toxicity from external beam radiation therapy in breast cancer patients: protective effects of Resveratrol, Lycopene, Vitamin C and anthocianin (Ixor®)

    International Nuclear Information System (INIS)

    Franco, Rossella Di; Calvanese, MariaGrazia; Murino, Paola; Manzo, Roberto; Guida, Cesare; Gennaro, Davide Di; Anania, Caterina; Ravo, Vincenzo

    2012-01-01

    This is an observational study and the aim is to evaluate the effect of dietary supplements based on Resveratrol, Lycopene, Vitamin C and Anthocyanins (Ixor ® ) in reducing skin toxicity due to external beam radiotherapy in patients affected by breast cancer. 71 patients were enrolled and they were divided in two different groups: a control group (CG) of 41 patients treated with prophylactic topical therapy based on hyaluronic acid and topical steroid therapy in case of occurrence of radiodermatitis, and a Ixor-Group (IG) of 30 patients treated also with an oral therapy based on Resveratrol, Lycopene, Vitamin C and Anthocyanin (Ixor ® ) at a dose of 2 tablets/day, starting from 10 days before the radiation treatment until 10 days after the end of treatment. Skin toxicity has been related to PTV, to breast volume that received a radiation dose equal or lower than 107%, included between 107% and 110%, or greater than 110% of the prescribed dose. Moreover it's been studied the relationship between skin toxicity and the chemotherapy schedule used before treatment. We calculated in both groups the percentage of patients who had a skin toxicity of grade 2 or 3 (according to RTOG scale). Absolute risk reduction (ARR), relative risk (RR) and odds ratio (OR) have been calculated for each relationship. Control Group (CG) patients with a PTV > 500 ml presented skin toxicity G2 + G3 in 30% of cases, versus 25% of Ixor-Group (IG) [OR 0.77]. In patients with a PTV < 500 ml G2 + G3 toxicity was 0% in the IG compared to 18% in CG (OR 0.23). When Dmax was less than or equal to 107% of the prescribed dose skin toxicity was G2 + G3 in 12.5% in CG, versus 0% in IG (OR 0.73), instead when Dmax was included between 107 and 110% of the prescribed dose, G2 + G3 skin toxicity was 35% in CG and 21% in IG (OR 0.50). In patients undergoing chemotherapy with anthracyclines and taxanes, G2 + G3 toxicity was 27% in CG, against 20% in IG (OR 0.68). The protective effect of Resveratrol

  18. Californium-252 Brachytherapy Combined With External-Beam Radiotherapy for Cervical Cancer: Long-Term Treatment Results

    International Nuclear Information System (INIS)

    Lei Xin; Qian Chengyuan; Qing Yi; Zhao Kewei; Yang Zhengzhou; Dai Nan; Zhong Zhaoyang; Tang Cheng; Li Zheng; Gu Xianqing; Zhou Qian; Feng Yan; Xiong Yanli; Shan Jinlu; Wang Dong

    2011-01-01

    Purpose: To observe, by retrospective analysis, the curative effects and complications due to californium-252 ( 252 Cf) neutron intracavitary brachytherapy (ICBT) combined with external-beam radiotherapy (EBRT) in the treatment of cervical cancer. Methods and Materials: From February 1999 to December 2007, 696 patients with cervical cancer (Stages IB to IIIB) were treated with 252 Cf-ICBT in combination of EBRT. Of all, 31 patients were at Stage IB, 104 at IIA, 363 at IIB, 64 at IIIA, and 134 at IIIB. Californium-252 ICBT was delivered at 7–12 Gy per insertion per week, with a total dose of 29–45 Gy to reference point A in three to five insertions. The whole pelvic cavity was treated with 8-MV X-ray external irradiation at 2 Gy per fraction, four times per week. After 16–38 Gy of external irradiation, the center of the whole pelvic field was blocked with a 4-cm-wide lead shield, with a total external irradiation dose of 44–56 Gy. The total treatment course was 5 to 6 weeks. Results: Overall survival rate at 3 and 5 years for all patients was 76.0% and 64.9%, respectively. Disease-free 3- and 5-year survival rates of patients were 71.2% and 58.4%, respectively. Late complications included vaginal contracture and adhesion, radiation proctitis, radiation cystitis, and inflammatory bowel, which accounted for 5.8%, 7.1%, 6.2%, and 4.9%, respectively. Univariate analysis results showed significant correlation of stage, age, histopathologic grade, and lymph node status with overall survival. Cox multiple regression analysis showed that the independent variables were stage, histopathologic grade, tumor size, and lymphatic metastasis in all patients. Conclusion: Results of this series suggest that the combined use of 252 Cf-ICBT with EBRT is an effective method for treatment of cervical cancer.

  19. Can All Centers Plan Intensity-Modulated Radiotherapy (IMRT) Effectively? An External Audit of Dosimetric Comparisons Between Three-Dimensional Conformal Radiotherapy and IMRT for Adjuvant Chemoradiation for Gastric Cancer

    International Nuclear Information System (INIS)

    Chung, Hans T.; Lee, Brian; Park, Eileen; Lu, Jiade J.; Xia Ping

    2008-01-01

    Purpose: To compare dosimetric endpoints between three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) at our center with limited IMRT experience, and to perform an external audit of the IMRT plans. Methods and Materials: Ten patients, who received adjuvant chemoradiation for gastric cancer, formed the study cohort. For standardization, the planning target volume (PTV) and organs at risk were recontoured with the assistance of a study protocol radiologic atlas. The cohort was replanned with CMS Xio to generate coplanar 3D-CRT and IMRT plans. All 10 datasets, including volumes but without the plans (i.e., blinded), were transmitted to an experienced center where IMRT plans were designed using Nomos Corvus (IMRT-C) and ADAC Pinnacle (IMRT-P). All IMRT plans were normalized to D95% receiving 45 Gy. Results: Intensity-modulated radiotherapy yielded higher PTV V45 (volume that receives ≥45 Gy) (p < 0.001) than 3D-CRT. No difference in V20 was seen in the right (p = 0.9) and left (p 0.3) kidneys, but the liver mean dose (p < 0.001) was superior with IMRT. For the external audit, IMRT-C (p = 0.002) and IMRT-P (p < 0.001) achieved significantly lower left kidney V20 than IMRT, and IMRT-P (p < 0.001) achieved lower right kidney V20 than IMRT. The IMRT-C (p = 0.003) but not IMRT-P (p = 0.6) had lower liver mean doses than IMRT. Conclusions: At our institution with early IMRT experience, IMRT improved PTV dose coverage and liver doses but not kidney doses. An external audit of IMRT plans showed that an experienced center can yield superior IMRT plans

  20. Evaluation of the Induced Activity in Air by the External Proton Beam in the Target Room of the Proton Accelerator Facility of Proton Engineering Frontier Project

    International Nuclear Information System (INIS)

    Lee, Cheol Woo; Lee, Young Ouk; Cho, Young Sik; Ahn, So Hyun

    2007-01-01

    One of the radiological concerns is the worker's exposure level and the concentration of the radionuclides in the air after shutdown, for the safety analysis on the proton accelerator facility. Although, the primary radiation source is the protons accelerated up to design value, all of the radio-nuclide is produced from the secondary neutron and photon induced reaction in air. Because, the protons don't penetrate the acceleration equipment like the DTL tank wall or BTL wall, secondary neutrons or photons are only in the air in the accelerator tunnel building because of the short range of the proton in the materials. But, for the case of the target rooms, external proton beams are occasionally used in the various experiments. When these external proton beams travel through air from the end of the beam transport line to the target, they interact directly with air and produce activation products from the proton induced reaction. The external proton beam will be used in the target rooms in the accelerator facility of the Proton Accelerator Frontier Project (PEFP). In this study, interaction characteristics of the external proton beam with air and induced activity in air from the direct interaction of the proton beam were evaluated

  1. External beam radiotherapy for head and neck carcinomas with preservation of parotid function: indications, techniques and long term results

    International Nuclear Information System (INIS)

    Ding-Jen, Lee; Fairbanks, Robert; Lee, Frank C.

    1995-01-01

    Purpose/Objective: To reduce the incidence of radiotherapy induced xerostomia, we developed techniques of external beam irradiation with preservation of parotid function for patients with early to intermediate stage carcinomas of the head and neck. This analysis reports the efficacy of our methods. Materials and Methods: From 1985 to 1993, 42 patients with early to intermediate stage (T 1-3 N 0-2 M 0 ) head and neck carcinomas received a course of external beam radiotherapy. There were 13 patients with carcinoma of the oropharynx, 26 with carcinomas of the oral cavity and 3 with carcinomas of the hypopharynx (lateral wall). 7 patients received a course of definitive radiotherapy (66 to 72 Gy), while 35 patients received a course of postoperative radiotherapy (60-66 Gy). The fraction size was 2 Gy per day. In terms of treatment planning, the primary site (plus a margin) and the ipsilateral neck were covered by the irradiation volume. The ipsilateral parotid gland was within the treatment volume while the contralateral parotid gland was not. The most frequently used field arrangement was a paired wedge fields with an AP (medially just across the mid-line) and an ipsilateral posterior oblique field (usually 30 deg. off vertical axis with a spinal cord block). Multiple level of contours were taken and transmission blocks were used to improve dose homogeneity. In all patients, the ipsilateral parotid gland (and the neck) was irradiated while the contralateral parotid gland (and the neck) was not. Results: With a median follow up of 4 years (ranged from 1.5 to 9 years), only one patient developed symptomatic xerostomia. None had radiation induced dental caries. No patient developed recurrent disease in the contralateral neck. The local control rate was (38(42)) (90%) in the primary site and(41(42)) (98%) in the ipsilateral neck. Conclusion: With appropriate treatment planning, external beam irradiation with parotid function preservation can be achieved. Our results

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

    International Nuclear Information System (INIS)

    Alan, E.; Nahum, PhD.

    2003-01-01

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

  3. External-beam PIXE characterization of volcanic material used in ancient Roman mortars

    International Nuclear Information System (INIS)

    Sonck-Koota, P.; Lindroos, A.; Lill, J.-O.; Rajander, J.; Viitanen, E.-M.; Marra, F.; Pehkonen, M.H.; Suksi, J.; Heselius, S.-J.

    2008-01-01

    Volcanic deposits from two volcanic districts, Monti Sabatini (MSVD) and Colli Albani (CAVD), NW and SE of Rome, were analyzed using the particle-induced X-ray emission (PIXE) technique, in order to obtain chemical fingerprints that can be used for provenance studies of filler materials in ancient Roman mortars. The rock samples were mounted on an X-Y stage enabling scanning over the sample surface and irradiated in air with a collimated 3 MeV proton beam. The samples were either analyzed by scanning the beam over a polished surface or they were crushed, ground and homogenized prior to the irradiation. However, scanning over polished sample surfaces avoiding heterogeneities gave quite similar results as scanning over pellet surfaces, especially for the minor and trace elements. This study shows that the deposits of MSVD and CAVD can be distinguished from each other. Several elements or elemental ratios can be used to characterize the districts. Even the individual volcanic deposits of CAVD can be identified

  4. Limb-sparing management with surgical resection, external-beam and intraoperative electron-beam radiation therapy boost for patients with primary soft tissue sarcoma of the extremity. A multicentric pooled analysis of long-term outcomes

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Felipe A. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Complutense University, School of Medicine, Madrid (Spain); Sole, Claudio V. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); Complutense University, School of Medicine, Madrid (Spain); Instituto de Radiomedicina, Service of Radiation Oncology, Santiago (Chile); Polo, Alfredo; Montero, Angel [Hospital Universitario Ramon y Cajal, Service of Radiation Oncology, Madrid (Spain); Cambeiro, Mauricio; Martinez-Monge, Rafael [Clinica Universidad de Navarra, Service of Radiation Oncology, Pamplona (Spain); Alvarez, Ana [Hospital General Universitario Gregorio Maranon, Service of Radiation Oncology, Madrid (Spain); Cuervo, Miguel [Hospital General Universitario Gregorio Maranon, Service of Orthopedics and Traumatology, Madrid (Spain); Julian, Mikel San [Clinica Universidad de Navarra, Service of Orthopedics and Traumatology, Pamplona (Spain)

    2014-10-15

    A joint analysis of data from three contributing centres within the intraoperative electron-beam radiation therapy (IOERT) Spanish program was performed to investigate the main contributions of IORT to the multidisciplinary treatment of high-risk extremity soft tissue sarcoma (STS). Patients with an histologic diagnosis of primary extremity STS, with absence of distant metastases, undergoing limb-sparing surgery with radical intent, external beam radiotherapy (median dose 45 Gy) and IOERT (median dose 12.5 Gy) were considered eligible for participation in this study. From 1986-2012, a total of 159 patients were analysed in the study from three Spanish institutions. With a median follow-up time of 53 months (range 4-316 years), 5-year local control (LC) was 82 %. The 5-year IOERT in-field control, disease-free survival (DFS) and overall survival (OS) were 86, 62 and 72 %, respectively. On multivariate analysis, only microscopically involved margin (R1) resection status retained significance in relation to LC (HR 5.20, p < 0.001). With regard to IOERT in-field control, incomplete resection (HR 4.88, p = 0.001) and higher IOERT dose (≥ 12.5 Gy; HR 0.32, p = 0.02) retained a significant association in multivariate analysis. From this joint analysis emerges the fact that an IOERT dose ≥ 12.5 Gy increases the rate of IOERT in-field control, but DFS remains modest, given the high risk of distant metastases. Intensified local treatment needs to be tested in the context of more efficient concurrent, neo- and adjuvant systemic therapy. (orig.) [German] Um den therapeutischen Beitrag einer intraoperativen Bestrahlung mit Elektronen (IOERT) als Teil eines multidisziplinaeren Behandlungskonzepts von Weichteilsarkomen (STS) im Extremitaetenbereich mit hohem Risikoprofil evaluieren zu koennen, wurde anhand des spanischen IOERT-Programms eine gepoolte Datenanalyse von drei teilnehmenden Zentren vorgenommen. Eingeschlossen in diese Studie wurden Patienten mit histologisch

  5. External beam techniques to boost cervical cancer when brachytherapy is not an option—theories and applications

    Science.gov (United States)

    Kilic, Sarah; Khan, Atif J.; Beriwal, Sushil; Small, William

    2017-01-01

    The management of locally advanced cervical cancer relies on brachytherapy (BT) as an integral part of the radiotherapy delivery armamentarium. Occasionally, intracavitary BT is neither possible nor available. In these circumstances, post-external beam radiotherapy (EBRT) interstitial brachytherapy and/or hysterectomy may represent viable options that must be adequately executed in a timely manner. However, if these options are not applicable due to patient related or facility related reasons, a formal contingency plan should be in place. Innovative EBRT techniques such as intensity modulated and stereotactic radiotherapy may be considered for patients unable to undergo brachytherapy. Relying on provocative arguments and recent data, this review explores the rationale for and limitations of non-brachytherapy substitutes in that setting aiming to establish a formal process for the optimal execution of this alternative plan. PMID:28603722

  6. Evaluation by PIXE external beam-of the leaching efficiency for a thermo stated column for the sand treatment

    International Nuclear Information System (INIS)

    Aspiazu, J.; Vite, J.; Vivero, R.; Mendez, B.

    1995-01-01

    The purpose of this paper was to measure the leaching efficiency for a thermo stated column designed to extract metals in muds originated by foundry process. The results obtained were useful to contemplate different alternatives helping to solve the problem of stocking enormous volumes of polluted sand produced by industries. Samples of residual sands and muds (treated sands) coming from an engine factory and from a thermo stated column respectively, were irradiated using an external beam of 3.55 MeV energy protons. From the quantitative analysis PIXE (Proton Induced X-ray Emission), it was possible to establish the level of pollution in sands due to the foundry processes and to evaluate the leaching efficiency of the output liquid phase from the thermo stated column. For polluted sands, certain cases were observed for which the efficiency was not enough to decrease the level of pollution in, e.g., Cu, Zn, Br and Pb. (Author)

  7. Evaluation by PIXE external beam of the leaching efficiency for a thermo stated column for the sand treatment

    International Nuclear Information System (INIS)

    Aspiazu, J.; Vite, J.; Vivero, R.; Mendez, B.

    1995-01-01

    The purpose of this paper was to measure the leaching efficiency for a thermo stated column designed to extract metals in muds originated by foundry processes. The results obtained were useful to contemplate different alternatives helping to solve the problem of stocking enormous volumes of polluted sand produced by industries. Samples of residual sands and muds (treated sands) coming from an engine factory and from a thermo stated column respectively, were irradiated using an external beam of 3.55 MeV energy protons. From the quantitative analysis PIXE (Proton Induced X-ray Emission), it was possible to establish the level of pollution in sands due to the foundry processes and to evaluate the leaching efficiency of the output liquid phase from the thermo stated column. For polluted sands, certain cases were observed for which the efficiency was not enough to decrease the level of pollution in e.g., Cu, Zn, Br y Pb. (Author)

  8. Combination of peptide receptor radionuclide therapy with fractionated external beam radiotherapy for treatment of advanced symptomatic meningioma

    International Nuclear Information System (INIS)

    Kreissl, Michael C; Flentje, Michael; Sweeney, Reinhart A; Hänscheid, Heribert; Löhr, Mario; Verburg, Frederik A; Schiller, Markus; Lassmann, Michael; Reiners, Christoph; Samnick, Samuel S; Buck, Andreas K

    2012-01-01

    External beam radiotherapy (EBRT) is the treatment of choice for irresectable meningioma. Due to the strong expression of somatostatin receptors, peptide receptor radionuclide therapy (PRRT) has been used in advanced cases. We assessed the feasibility and tolerability of a combination of both treatment modalities in advanced symptomatic meningioma. 10 patients with irresectable meningioma were treated with PRRT ( 177 Lu-DOTA0,Tyr3 octreotate or - DOTA0,Tyr3 octreotide) followed by external beam radiotherapy (EBRT). EBRT performed after PRRT was continued over 5–6 weeks in IMRT technique (median dose: 53.0 Gy). All patients were assessed morphologically and by positron emission tomography (PET) before therapy and were restaged after 3–6 months. Side effects were evaluated according to CTCAE 4.0. Median tumor dose achieved by PRRT was 7.2 Gy. During PRRT and EBRT, no side effects > CTCAE grade 2 were noted. All patients reported stabilization or improvement of tumor-associated symptoms, no morphologic tumor progression was observed in MR-imaging (median follow-up: 13.4 months). The median pre-therapeutic SUV max in the meningiomas was 14.2 (range: 4.3–68.7). All patients with a second PET after combined PRRT + EBRT showed an increase in SUV max (median: 37%; range: 15%–46%) to a median value of 23.7 (range: 8.0–119.0; 7 patients) while PET-estimated volume generally decreased to 81 ± 21% of the initial volume. The combination of PRRT and EBRT is feasible and well tolerated. This approach represents an attractive strategy for the treatment of recurring or progressive symptomatic meningioma, which should be further evaluated

  9. Statistical Modeling of the Eye for Multimodal Treatment Planning for External Beam Radiation Therapy of Intraocular Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Rueegsegger, Michael B. [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland); Bach Cuadra, Meritxell [Department of Radiology, University Hospital Center (CHUV) and University of Lausanne (UNIL), Signal Processing Laboratory - LTS5, Ecole Polytechnique Federale de Lausanne (Switzerland); Pica, Alessia [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Amstutz, Christoph A. [Department of Ophthalmology, University Hospital Zurich (Switzerland); Rudolph, Tobias [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland); Aebersold, Daniel [Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern (Switzerland); Kowal, Jens H., E-mail: jens.kowal@artorg.unibe.ch [ARTORG Center for Biomedical Engineering Research, University of Bern (Switzerland)

    2012-11-15

    Purpose: Ocular anatomy and radiation-associated toxicities provide unique challenges for external beam radiation therapy. For treatment planning, precise modeling of organs at risk and tumor volume are crucial. Development of a precise eye model and automatic adaptation of this model to patients' anatomy remain problematic because of organ shape variability. This work introduces the application of a 3-dimensional (3D) statistical shape model as a novel method for precise eye modeling for external beam radiation therapy of intraocular tumors. Methods and Materials: Manual and automatic segmentations were compared for 17 patients, based on head computed tomography (CT) volume scans. A 3D statistical shape model of the cornea, lens, and sclera as well as of the optic disc position was developed. Furthermore, an active shape model was built to enable automatic fitting of the eye model to CT slice stacks. Cross-validation was performed based on leave-one-out tests for all training shapes by measuring dice coefficients and mean segmentation errors between automatic segmentation and manual segmentation by an expert. Results: Cross-validation revealed a dice similarity of 95% {+-} 2% for the sclera and cornea and 91% {+-} 2% for the lens. Overall, mean segmentation error was found to be 0.3 {+-} 0.1 mm. Average segmentation time was 14 {+-} 2 s on a standard personal computer. Conclusions: Our results show that the solution presented outperforms state-of-the-art methods in terms of accuracy, reliability, and robustness. Moreover, the eye model shape as well as its variability is learned from a training set rather than by making shape assumptions (eg, as with the spherical or elliptical model). Therefore, the model appears to be capable of modeling nonspherically and nonelliptically shaped eyes.

  10. High biologically effective dose radiation therapy using brachytherapy in combination with external beam radiotherapy for high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Keisei Okamoto

    2017-02-01

    Full Text Available Purpose : To evaluate the outcomes of high-risk prostate cancer patients treated with biologically effective dose (BED ≥ 220 Gy of high-dose radiotherapy, using low-dose-rate (LDR brachytherapy in combination with external beam radiotherapy (EBRT and short-term androgen deprivation therapy (ADT. Material and methods : From 2005 to 2013, a total of 143 patients with high-risk prostate cancer were treated by radiotherapy of BED ≥ 220 Gy with a combination of LDR brachytherapy, EBRT, and androgen deprivation therapy (ADT. The high-risk patients in the present study included both high-risk and very high-risk prostate cancer. The number of high-risk features were: 60 patients with 1 high-risk factor (42%, 61 patients with 2 high-risk factors (43%, and 22 patients with 3 high-risk factors (15% including five N1 disease. External beam radiotherapy fields included prostate and seminal vesicles only or whole pelvis depending on the extension of the disease. Biochemical failure was defined by the Phoenix definition. Results : Six patients developed biochemical failure, thus providing a 5-year actual biochemical failure-free survival (BFFS rate of 95.2%. Biochemical failure was observed exclusively in cases with distant metastasis in the present study. All six patients with biochemical relapse had clinical failure due to bone metastasis, thus yielding a 5-year freedom from clinical failure (FFCF rate of 93.0%. None of the cases with N1 disease experienced biochemical failure. We observed four deaths, including one death from prostate cancer, therefore yielding a cause-specific survival (CSS rate of 97.2%, and an overall survival (OS rate of 95.5%. Conclusions : High-dose (BED ≥ 220 Gy radiotherapy by LDR in combination with EBRT has shown an excellent outcome on BFFS in high-risk and very high-risk cancer, although causal relationship between BED and BFFS remain to be explained further.

  11. Statistical modeling of the eye for multimodal treatment planning for external beam radiation therapy of intraocular tumors.

    Science.gov (United States)

    Rüegsegger, Michael B; Bach Cuadra, Meritxell; Pica, Alessia; Amstutz, Christoph A; Rudolph, Tobias; Aebersold, Daniel; Kowal, Jens H

    2012-11-15

    Ocular anatomy and radiation-associated toxicities provide unique challenges for external beam radiation therapy. For treatment planning, precise modeling of organs at risk and tumor volume are crucial. Development of a precise eye model and automatic adaptation of this model to patients' anatomy remain problematic because of organ shape variability. This work introduces the application of a 3-dimensional (3D) statistical shape model as a novel method for precise eye modeling for external beam radiation therapy of intraocular tumors. Manual and automatic segmentations were compared for 17 patients, based on head computed tomography (CT) volume scans. A 3D statistical shape model of the cornea, lens, and sclera as well as of the optic disc position was developed. Furthermore, an active shape model was built to enable automatic fitting of the eye model to CT slice stacks. Cross-validation was performed based on leave-one-out tests for all training shapes by measuring dice coefficients and mean segmentation errors between automatic segmentation and manual segmentation by an expert. Cross-validation revealed a dice similarity of 95%±2% for the sclera and cornea and 91%±2% for the lens. Overall, mean segmentation error was found to be 0.3±0.1 mm. Average segmentation time was 14±2 s on a standard personal computer. Our results show that the solution presented outperforms state-of-the-art methods in terms of accuracy, reliability, and robustness. Moreover, the eye model shape as well as its variability is learned from a training set rather than by making shape assumptions (eg, as with the spherical or elliptical model). Therefore, the model appears to be capable of modeling nonspherically and nonelliptically shaped eyes. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. American Brachytherapy Society Task Group Report: Combination of brachytherapy and external beam radiation for high-risk prostate cancer.

    Science.gov (United States)

    Spratt, Daniel E; Soni, Payal D; McLaughlin, Patrick W; Merrick, Gregory S; Stock, Richard G; Blasko, John C; Zelefsky, Michael J

    To review outcomes for high-risk prostate cancer treated with combined modality radiation therapy (CMRT) utilizing external beam radiation therapy (EBRT) with a brachytherapy boost. The available literature for high-risk prostate cancer treated with combined modality radiation therapy was reviewed and summarized. At this time, the literature suggests that the majority of high-risk cancers are curable with multimodal treatment. Several large retrospective studies and three prospective randomized trials comparing CMRT to dose-escalated EBRT have demonstrated superior biochemical control with CMRT. Longer followup of the randomized trials will be required to determine if this will translate to a benefit in metastasis-free survival, disease-specific survival, and overall survival. Although greater toxicity has been associated with CMRT compared to EBRT, recent studies suggest that technological advances that allow better definition and sparing of critical adjacent structures as well as increasing experience with brachytherapy have improved implant quality and the toxicity profile of brachytherapy. The role of androgen deprivation therapy is well established in the external beam literature for high-risk disease, but there is controversy regarding the applicability of these data in the setting of dose escalation. At this time, there is not sufficient evidence for the omission of androgen deprivation therapy with dose escalation in this population. Comparisons with surgery remain limited by differences in patient selection, but the evidence would suggest better disease control with CMRT compared to surgery alone. Due to a series of technological advances, modern combination series have demonstrated unparalleled rates of disease control in the high-risk population. Given the evidence from recent randomized trials, combination therapy may become the standard of care for high-risk cancers. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All

  13. Phase II study of concurrent capecitabine and external beam radiotherapy for pain control of bone metastases of breast cancer origin.

    Directory of Open Access Journals (Sweden)

    Yulia Kundel

    Full Text Available Pain from bone metastases of breast cancer origin is treated with localized radiation. Modulating doses and schedules has shown little efficacy in improving results. Given the synergistic therapeutic effect reported for combined systemic chemotherapy with local radiation in anal, rectal, and head and neck malignancies, we sought to evaluate the tolerability and efficacy of combined capecitabine and radiation for palliation of pain due to bone metastases from breast cancer.Twenty-nine women with painful bone metastases from breast cancer were treated with external beam radiation in 10 fractions of 3 Gy, 5 fractions a week for 2 consecutive weeks. Oral capecitabine 700 mg/m(2 twice daily was administered throughout radiation therapy. Rates of complete response, defined as a score of 0 on a 10-point pain scale and no increase in analgesic consumption, were 14% at 1 week, 38% at 2 weeks, 52% at 4 weeks, 52% at 8 weeks, and 48% at 12 weeks. Corresponding rates of partial response, defined as a reduction of at least 2 points in pain score without an increase in analgesics consumption, were 31%, 38%, 28%, 34% and 38%. The overall response rate (complete and partial at 12 weeks was 86%. Side effects were of mild intensity (grade I or II and included nausea (38% of patients, weakness (24%, diarrhea (24%, mucositis (10%, and hand and foot syndrome (7%.External beam radiation with concurrent capecitabine is safe and tolerable for the treatment of pain from bone metastases of breast cancer origin. The overall and complete response rates in our study are unusually high compared to those reported for radiation alone. Further evaluation of this approach, in a randomized study, is warranted.ClinicalTrials.gov NCT01784393NCT01784393.

  14. Characterization of the Teotihuacan mural painting: application of the external particle beam as non destructive technique

    International Nuclear Information System (INIS)

    Martinez, C.; Manzanilla, L.; Ruvalcaba, J.L.; Ontalba, M.A.

    2005-01-01

    The characterization of technical indicators contained in the painting mural should follow a minim methodology from their discovery in the archaeological excavations until their analysis in the laboratory, with the purpose of rescuing diagnostic elements that mark the stages of socio cultural development in the towns. With this spirit it was carried out the present study analyzing some fragments of the Teotihuacan mural painting. The analysis consisted on applying some of the analytical techniques with particle beams used for archaeometry like the Proton induced X-ray emission (PIXE) and the particle elastic backscattering (RBS), due to it is treated of complementary techniques, very sensitive, of multielemental character, but mainly because its are non destructive analytical techniques. (Author)

  15. UCN sources at external beams of thermal neutrons. An example of PIK reactor

    International Nuclear Information System (INIS)

    Lychagin, E.V.; Mityukhlyaev, V.A.; Muzychka, A.Yu.; Nekhaev, G.V.; Nesvizhevsky, V.V.; Onegin, M.S.; Sharapov, E.I.; Strelkov, A.V.

    2016-01-01

    We consider ultracold neutron (UCN) sources based on a new method of UCN production in superfluid helium ("4He). The PIK reactor is chosen as a perspective example of application of this idea, which consists of installing "4He UCN source in the beam of thermal or cold neutrons and surrounding the source with moderator-reflector, which plays the role of cold neutron (CN) source feeding the UCN source. CN flux in the source can be several times larger than the incident flux, due to multiple neutron reflections from the moderator–reflector. We show that such a source at the PIK reactor would provide an order of magnitude larger density and production rate than an analogous source at the ILL reactor. We estimate parameters of "4He source with solid methane (CH_4) or/and liquid deuterium (D_2) moderator–reflector. We show that such a source with CH_4 moderator–reflector at the PIK reactor would provide the UCN density of ~1·10"5 cm"−"3, and the UCN production rate of ~2·10"7 s"−"1. These values are respectively 1000 and 20 times larger than those for the most intense UCN user source. The UCN density in a source with D_2 moderator-reflector would reach the value of ~2·10"5 cm"−"3, and the UCN production rate would be equal ~8·10"7 s"−"1. Installation of such a source in a beam of CNs would slightly increase the density and production rate.

  16. Diode In-vivo Dosimetry for External Beam Radiotherapy: Patient Data Analysis

    International Nuclear Information System (INIS)

    Mrcela, I.; Bokulic, T.; Budanec, M; Froebe, A.; Soldic, Z.; Kusic, Z.

    2008-01-01

    In-vivo dosimetry is known as simple and reliable method for checking the final accuracy of the dose delivered in external radiotherapy making a supplement to the regular quality control. Entrance dose measurements in the beginning of the treatment assure detection of major errors that can affect the therapy outcome. Silicon diodes are often the detectors of choice for their ability of real time dose measurements and the simplicity of use. There are many publications describing the procedures for the implementation of in-vivo dosimetry. Routine in-vivo dosimetry has been introduced in our department after initial procedures including physical characterization, calibration and determination of correction factors for the detectors in use. This work presents patient data analysis with more than 700 field measurements taken in last 2 years period

  17. Tri-Modality therapy with I-125 brachytherapy, external beam radiation therapy, and short- or long-term hormone therapy for high-risk localized prostate cancer (TRIP: study protocol for a phase III, multicenter, randomized, controlled trial

    Directory of Open Access Journals (Sweden)

    Konaka Hiroyuki

    2012-03-01

    Full Text Available Abstract Background Patients with high Gleason score, elevated prostate specific antigen (PSA level, and advanced clinical stage are at increased risk for both local and systemic relapse. Recent data suggests higher radiation doses decrease local recurrence and may ultimately benefit biochemical, metastasis-free and disease-specific survival. No randomized data is available on the benefits of long-term hormonal therapy (HT in these patients. A prospective study on the efficacy and safety of trimodality treatment consisting of HT, external beam radiation therapy (EBRT, and brachytherapy (BT for high-risk prostate cancer (PCa is strongly required. Methods/Design This is a phase III, multicenter, randomized controlled trial (RCT of trimodality with BT, EBRT, and HT for high-risk PCa (TRIP that will investigate the impact of adjuvant HT following BT using iodine-125 (125I-BT and supplemental EBRT with neoadjuvant and concurrent HT. Prior to the end of September 2012, a total of 340 patients with high-risk PCa will be enrolled and randomized to one of two treatment arms. These patients will be recruited from more than 41 institutions, all of which have broad experience with 125I-BT. Pathological slides will be centrally reviewed to confirm patient eligibility. The patients will commonly undergo 6-month HT with combined androgen blockade (CAB before and during 125I-BT and supplemental EBRT. Those randomly assigned to the long-term HT group will subsequently undergo 2 years of adjuvant HT with luteinizing hormone-releasing hormone agonist. All participants will be assessed at baseline and every 3 months for the first 30 months, then every 6 months until 84 months from the beginning of CAB. The primary endpoint is biochemical progression-free survival. Secondary endpoints are overall survival, clinical progression-free survival, disease-specific survival, salvage therapy non-adaptive interval, and adverse events. Discussion To our knowledge, there have

  18. A phase I/II study of external beam radiation, brachytherapy and concurrent chemotherapy in localized cancer of the esophagus (RTOG 9207)

    International Nuclear Information System (INIS)

    Gaspar, L.E.; Qian, C.; Kocha, W.I.; Coia, L.R.; Herskovic, A.; Graham, M.

    1996-01-01

    Introduction: A multi-institutional, prospective study was designed to determine the feasibility and toxicity of chemotherapy, external beam irradiation and esophageal brachytherapy (EB) in a potentially curable group of patients with adenocarcinoma or squamous cell carcinoma of the esophagus. Methods: Planned treatment was 50 Gy external beam radiation (25 fractions/5 wks) followed 2 weeks later by EB (either HDR 5 Gy wks 8,9 and 10 for a total of 15 Gy or LDR 20 Gy wk 8). The protocol was later revised to delete the LDR alternative due to poor accrual and decrease the HDR dose to 10 Gy, ie 5 Gy wks 8 and 9. Chemotherapy was given wks 1,5,8 and 11 with DDP 75 mg/m2 and 5-FU 1000 mg/m2/24 hrs, 96 hour infusion. Data is available on 50 patients (46 squamous, 3 adenocarcinoma) treated on the HDR alternative (EB dose 15 Gy and 10 Gy in 40 and 10 patients, respectively. Results: Thirty-five patients (70%) were able to complete external beam, EB and at least 2 courses of chemotherapy. Estimated survival rate at 12 months is 48%. Life-threatening toxicity or death occurred in 13 (26%) and 4 (8%) patients, respectively. Treatment-related esophageal fistulas occurred in 6 patients (12%) at 0.5 to 6.2 months from the first day of brachytherapy, leading to death in 3. So far all treatment-related fistulas occurred in the 15 Gy EB group. Conclusions: Survival following this combination of chemotherapy, external beam radiation and EB does not appear to be different from survival seen following chemotherapy and external beam radiation only. Based on the high incidence of fistulas, we urge extreme caution in employing EB as a boost following concurrent chemotherapy and external beam radiation with the schema utilized in this prospective study

  19. Coupled PIXE and RBS using a 6MeV 4He2+ external beam: A new experimental device for particle detection and dose monitoring

    International Nuclear Information System (INIS)

    Mathis, F.; Moignard, B.; Pichon, L.; Dubreuil, O.; Salomon, J.

    2005-01-01

    AGLAE (Accelerateur Grand Louvre d'Analyses Elementaire), the IBA facility of the 'Centre de Recherche et de Restauration des Musees de France' (C2RMF) has been equipped for several years with an external micro-beam line, in order to perform ion beam analysis on materials relevant to cultural heritage. This beam line is undergoing constant improvement. Recently, a new extraction nozzle for the external beam of the accelerator has been designed in order to obtain simultaneously from the same spot: - detection of the X-ray emission by two detectors, for low and high energies; - detection of the backscattered particles for a backscattering angle between 170 and 175 deg., thanks to an annular surface barrier detector included in the nozzle; - particle current monitoring by intermittent beam deflection on a reference material included in the system. This technical development has been induced by the study of artificial patinas on archaeological copper-alloy objects and the attempt to characterize them with a 6MeV 4 He 2+ beam, an unusual beam for this type of investigation. A detailed description of the new device and some results on an application of the use of high-energy alpha beam in PIXE and RBS made on a Roman strigil are presented here

  20. Elemental mapping of large samples by external ion beam analysis with sub-millimeter resolution and its applications

    Science.gov (United States)

    Silva, T. F.; Rodrigues, C. L.; Added, N.; Rizzutto, M. A.; Tabacniks, M. H.; Mangiarotti, A.; Curado, J. F.; Aguirre, F. R.; Aguero, N. F.; Allegro, P. R. P.; Campos, P. H. O. V.; Restrepo, J. M.; Trindade, G. F.; Antonio, M. R.; Assis, R. F.; Leite, A. R.

    2018-05-01

    The elemental mapping of large areas using ion beam techniques is a desired capability for several scientific communities, involved on topics ranging from geoscience to cultural heritage. Usually, the constraints for large-area mapping are not met in setups employing micro- and nano-probes implemented all over the world. A novel setup for mapping large sized samples in an external beam was recently built at the University of São Paulo employing a broad MeV-proton probe with sub-millimeter dimension, coupled to a high-precision large range XYZ robotic stage (60 cm range in all axis and precision of 5 μ m ensured by optical sensors). An important issue on large area mapping is how to deal with the irregularities of the sample's surface, that may introduce artifacts in the images due to the variation of the measuring conditions. In our setup, we implemented an automatic system based on machine vision to correct the position of the sample to compensate for its surface irregularities. As an additional benefit, a 3D digital reconstruction of the scanned surface can also be obtained. Using this new and unique setup, we have produced large-area elemental maps of ceramics, stones, fossils, and other sort of samples.

  1. Oncologic and functional outcome of base of tongue cancer treated with external-beam radiation and I-192 implant

    International Nuclear Information System (INIS)

    Harrison, L.B.; Sessions, R.B.; Strong, E.W.; Fass, D.E.; Armstrong, J.G.; Zelefsky, M.J.

    1991-01-01

    This paper assesses tumor control and functional outcome for squamous cancer of the base of the tongue managed with external irradiation plus Ir-192 implant. Between January 1981 and June 1990, 36 previously untreated patients were treated with 5,000-5,400 cGy of external-beam radiation plus a 2,000-3,000 cGy boost to the base of tongue with an Ir-192 implant. Negative necks were irradiated alone, and positive necks were treated with irradiation followed by neck dissection. Crude local control by T stage are as follows: T1, 10 of 11; T2, 13 of 14; T3, 8 of 10; and T4 1 of 1. Actuarial local control is 87.5%. Of the four local failures, two were salvaged by surgery. Neck control was achieved in 35 of 36 patients. Complications occurred in 25%. When implantation was done with the nonlooping technique, the injury rate was statistically higher than when done with the looping technique (6 of 12 = 50% vs 3 of 24 = 12.5%, P = .02)

  2. Normal tissue tolerance to external beam radiation therapy: Thyroid; Dose de tolerance des tissus sains: la thyroide

    Energy Technology Data Exchange (ETDEWEB)

    Berges, O.; Giraud, P. [Service d' oncologie-radiotherapie, hopital europeen Georges-Pompidou, universite Paris Descartes, 75 - Paris (France); Belkacemi, Y. [Service d' oncologie-radiotherapie, CHU Henri-Mondor, universite Paris 12, 94 - Creteil (France)

    2010-07-15

    The thyroid is the most developed endocrine gland of the body. Due to its anatomical location, it may be exposed to ionizing radiation in external radiotherapy involving head and neck. This review aims to describe the thyroid radiation disorders, probably under-reported in the literature, their risk factors and follow-up procedures. The functional changes after external beam radiation consists mainly of late effects occurring beyond 6 months, and are represented by the clinical and subclinical hypothyroidism. Its incidence is approximately 20 to 30% and it can occur after more than 25 years after radiation exposure. Hyperthyroidism and auto-immune manifestations have been described in a lesser proportion. The morphological changes consist of benign lesions, primarily adenomas, and malignant lesions, the most feared and which incidence is 0.35%. The onset of hypothyroidism depends of the total dose delivered to the gland, and the irradiated. Modern techniques of conformal radiotherapy with modulated intensity could improve the preservation of the thyroid, at the expense of the increase in low doses and the theoretical risk of secondary cancers. (authors)

  3. An external proton beam at VERA to study objects of art by proton induced x-ray emission (PIXE)

    International Nuclear Information System (INIS)

    Kroepfl, P.; Forstner, O.; Kutschera, W.; Priller, A.; Steier, P.; Wallner, A.; Wuenschek, B.; Golser, R.

    2006-01-01

    Full text: PIXE is a very sensitive analytical method to determine the chemical composition of art objects, e.g. drawings, handwritings etc. A particular advantage is the possibility to analyze objects non-destructively under atmospheric pressure. Such an external beam PIXE facility is currently implemented at the Vienna Environmental Research Accelerator (VERA). The set-up allows to extract a 3 MeV proton beam of approximately 100 μm in diameter and currents in the range of a few nA's through an ultra-thin (0.1 μm) Silicon Nitride window. The characteristic x-rays emitted from the specimen are recorded with a Si(Li) and a Silicon Drift detector simultaneously to cover the widest possible Z-range of the detected elements. We have just completed an extensive period of studying beam effects on ancient paper to exclude possible damage to art objects, in particular drawings of the Renaissance that are among the most precious and rarest treasuries of graphical collections. They were created with different materials such as inks, chalks and metal points. A large collection of these fine arts objects is situated at the Albertina in Vienna. Together with scientists from the Centre de Recherche et de Restauration des Musees de France (C2RMF) in Paris, I. Reiche, A. Duval, H. Guicharnaud, from the CEREGE UMR CNRS 6635 in Aix-en-Provence, S. Merchel, from the Albertina in Vienna, E. Thobois, H. Singer, and from the Akademie der bildenden Kuenste in Vienna, M. Schreiner, we want then to analyze a few selected silverpoint drawings by Albrecht Duerer (1471-1528). (author)

  4. The new external ion beam analysis setup at the Demokritos Tandem accelerator and first applications in cultural heritage

    International Nuclear Information System (INIS)

    Sokaras, Dimosthenis; Bistekos, Euthimios; Georgiou, Lambros; Salomon, Joseph; Bogovac, Mladen; Aloupi-Siotis, Eleni; Paschalis, Vasilis; Aslani, Ioanna; Karabagia, Sofia; Lagoyannis, Anastasios; Harissopulos, Sotirios; Kantarelou, Vasiliki; Karydas, Andreas-Germanos

    2011-01-01

    At the 5.5 MV Tandem VdG accelerator of the Institute of Nuclear Physics of N.C.S.R. 'Demokritos', Athens, Greece, an external ion-beam set-up has been recently developed and installed. The aim of this development was to integrate the analytical capabilities of the PIXE, RBS and PIGE ion beam techniques in one experimental set-up, so that to attain a complete elemental and near surface structural characterization of samples in an almost non-destructive way and without any limitation concerning their size or conductive state. A careful 3D mechanical drawing optimized the set-up experimental parameters achieving probe dimensions at the millimeter range (1 mm 2 ) and fulfilling the special requirements imposed for optimum performance of the aforementioned techniques, including the possibility to use heavier, than protons, ion beams. For the digital pulse processing of the X-ray, γ-ray and charged particle detector signals, novel hardware and software tools were developed based on a custom FPGA configuration. The first applications were focused in the quality control of materials that have been intentionally contaminated with a particular tracer-element ('tagged' materials). The tagged materials which were developed and tested are technologically authentic replicas of ancient attic ceramics with black glazed decoration. Analytical diagnostic studies were carried out for a few representative paintings of contemporary Greek painters in order to identify and document materials/pigments and techniques and eventually to prevent trade of fakes. Finally, ancient glass beads were also examined with respect to the sodium concentration and its in-depth homogeneity.

  5. Modelling of treatment couch top with prowess panther treatment planning system for external beam radiotherapy

    International Nuclear Information System (INIS)

    Owusu-Agyapong, Linus

    2016-07-01

    The aim of this work is to evaluate the attenuation effects of a treatment couch and to alternatively model the couch top material with a Prowess Panther treatment planning system which does not support couch top modelling. The Hounsfield Unit classification of the couch structure was determined using a PMMA phantom by comparing ion chamber measurements with the dose forecasted by the treatment planning system (TPS). The transmission factor (TF) of the couch top was determined and was used as a TF for a treatment accessory that represented the treatment couch in the TPS. A treatment plan was done for various angles with and without the interference of the couch top and a simulated treatment was done using the PMMA phantom. Ion chamber measurement were made and compared with dose predicted by the TPS to evaluate the accuracy of the couch top modelling in the treatment planning system TPS. These investigations were done for various field sizes. The ideal set of HU for the couch was established to be -674. The measured TF was 0.956042 and the TPS calculated Transmission factor was 0.951456. The percentage difference between the measured and calculated TFs was 0.48% and this agrees perfectly with the IAEA recommended tolerance of 2%. Relative attenuation measurements were as high as 54.16% and as low as 0.63% for the beams that exited the couch before interacting with the phantom. In comparing couch modelling by couch simulation and couch TF insert, it was observed that the normalized doses were the same for 5×5 square field but deviated approximately 1% for the other field sizes. The highest deviation was observed at 10×10 square field. This study demonstrates that the couch simulation method of couch modelling is the best method that can be used to account for the effect of the treatment couch top on intersecting posterior beam fields. Thus, the attenuation effects of the treatment couch was effectively evaluated and the couch top material accurately modelled in

  6. The influence of single and fractionated dose external beam irradiation on injury-induced arterial smooth muscle cell proliferation

    International Nuclear Information System (INIS)

    Schaefer, U.; Micke, O.; Dorszewski, A.; Breithardt, G.; Willich, N.

    1997-01-01

    Purpose/Objective: Restenosis after catheter-based revascularization has been demonstrated to be primarily caused by smooth muscle cell proliferation. This study examined the effects of external beam irradiation on neointimal proliferation after external injury to the central artery of the rabbit ear. Materials and Methods: 40 male New Zealand White rabbits were used in this study. Crush lesions were performed on each ear under general anesthesia and bilateral auricular nerve blockade. A single dose of 12 Gy (n=10), 16 Gy (n=10), or 20 Gy (n=10) and a fractionated dose of 4 x 5 Gy (n=10) gamma radiation was delivered to the left or right central artery of the ear 24 hours after injury; the contralateral central artery served as control. All rabbits were sacrificed after twenty-one days and the central arteries of the ear were fixed for morphometric measurements. Results: Mean (± SD) neointimal area was 0.062 ± 0.005 mm 2 (12 Gy), 0.022 ± 0,005 mm 2 (16 Gy), 0,028 ± 0,006 mm 2 and 0.038 mm 2 ± 0,02 mm 2 (4 x 5 Gy) in irradiated arteries compared with 0,081 ± 0,009 mm 2 in the control group. Mean (±SD) luminal area was 0.049 ± 0.004 mm 2 (12 Gy), 0.059 ± 0.002 mm 2 (16 Gy), 0.072 ± 0,006 mm 2 (20 Gy) and 0.048 mm 2 ± 0,018 mm 2 (4 x 5 Gy) in irradiated arteries compared with 0,043 ± 0,008 mm 2 in the control group. The difference in neointimal and luminal area between control and irradiated arteries was significant (p<0.05) only for the 16 and 20 Gy group compared to control. Conclusion: We conclude that in this model, external beam X-ray irradiation was successful in reducing neointimal proliferation after injury of the central artery of the rabbit ear. The optimal dose seems to be a single dose of 16 Gy - 20 Gy. Only a less prominent effect was noted for a fractionated dose of 4 x 5 Gy. Whether this approach can be used successfully to inhibit restenosis in the clinical setting requires further investigation

  7. Nonlinear rolling of a biased ship in a regular beam wave under external and parametric excitations

    Energy Technology Data Exchange (ETDEWEB)

    El-Bassiouny, A.F. [Mathematics Dept., Benha Univ., Benha (Egypt)

    2007-10-15

    We consider a nonlinear oscillator simultaneously excited by external and parametric functions. The oscillator has a bias parameter that breaks the symmetry of the motion. The example that we use to illustrate the problem is the rolling oscillation of a biased ship in longitudinal waves, but many mechanical systems display similar features. The analysis took into consideration linear, quadratic, cubic, quintic, and seven terms in the polynomial expansion of the relative roll angle. The damping moment consists of the linear term associated with radiation and viscous damping and a cubic term due to frictional resistance and eddies behind bilge keels and hard bilge corners. Two methods (the averaging and the multiple time scales) are used to investigate the first-order approximate analytical solution. The modulation equations of the amplitudes and phases are obtained. These equations are used to obtain the stationary state. The stability of the proposed solution is determined applying Liapunov's first method. Effects of different parameters on the system behaviour are investigated numerically. Results are presented graphically and discussed. The results obtained by two methods are in excellent agreement. (orig.)

  8. Change in volume of lumpectomy cavity during external-beam irradiation of the intact breast

    International Nuclear Information System (INIS)

    Jacobson, Geraldine; Betts, Vicki; Smith, Brian

    2006-01-01

    Purpose: Definition of the lumpectomy cavity is an important component of irradiation of the breast. We use computed tomography (CT)-based planning and contour the lumpectomy volume on the planning CT. We obtained a second CT in the 4th or 5th week of treatment for boost planning and compared the volume change with the first planning-CT scan. Methods and Materials: This retrospective study reviewed the planning-CT data for 20 patients. In the first CT, images were obtained from the mandible to 2 cm below the breast in 3-mm slices. In the second CT, for the boost, images were obtained from the top to the bottom of the clinically defined breast, in 3-mm slices. Lumpectomy cavities were contoured on both CT scans and volumes compared. Results: Sixteen of the 20 patients (80%) had more than a 20% decrease from the first to the second volume, with a corresponding 95% confidence interval. The mean decrease was 16.13 cc, with a standard deviation of 14.05. The Spearman correlation coefficient of 0.18 did not show a significant correlation between the initial volume and the percent change. Conclusions: During external breast irradiation, many patients will have significant volume reduction in the lumpectomy cavity. Because CT-based definition of the lumpectomy cavity can influence the planning of a boost technique, further study appears warranted

  9. Modification and validation of an analytical source model for external beam radiotherapy Monte Carlo dose calculations

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Scott E., E-mail: sedavids@utmb.edu [Radiation Oncology, The University of Texas Medical Branch, Galveston, Texas 77555 (United States); Cui, Jing [Radiation Oncology, University of Southern California, Los Angeles, California 90033 (United States); Kry, Stephen; Ibbott, Geoffrey S.; Followill, David S. [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Deasy, Joseph O. [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Vicic, Milos [Department of Applied Physics, University of Belgrade, Belgrade 11000 (Serbia); White, R. Allen [Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2016-08-15

    Purpose: A dose calculation tool, which combines the accuracy of the dose planning method (DPM) Monte Carlo code and the versatility of a practical analytical multisource model, which was previously reported has been improved and validated for the Varian 6 and 10 MV linear accelerators (linacs). The calculation tool can be used to calculate doses in advanced clinical application studies. One shortcoming of current clinical trials that report dose from patient plans is the lack of a standardized dose calculation methodology. Because commercial treatment planning systems (TPSs) have their own dose calculation algorithms and the clinical trial participant who uses these systems is responsible for commissioning the beam model, variation exists in the reported calculated dose distributions. Today’s modern linac is manufactured to tight specifications so that variability within a linac model is quite low. The expectation is that a single dose calculation tool for a specific linac model can be used to accurately recalculate dose from patient plans that have been submitted to the clinical trial community from any institution. The calculation tool would provide for a more meaningful outcome analysis. Methods: The analytical source model was described by a primary point source, a secondary extra-focal source, and a contaminant electron source. Off-axis energy softening and fluence effects were also included. The additions of hyperbolic functions have been incorporated into the model to correct for the changes in output and in electron contamination with field size. A multileaf collimator (MLC) model is included to facilitate phantom and patient dose calculations. An offset to the MLC leaf positions was used to correct for the rudimentary assumed primary point source. Results: Dose calculations of the depth dose and profiles for field sizes 4 × 4 to 40 × 40 cm agree with measurement within 2% of the maximum dose or 2 mm distance to agreement (DTA) for 95% of the data

  10. Successful treatment of a 67-year-old woman with urethral adenocarcinoma with the use of external beam radiotherapy and image guided adaptive interstitial brachytherapy

    DEFF Research Database (Denmark)

    Mujkanovic, Jasmin; Tanderup, Kari; Agerbæk, Mads

    2016-01-01

    Primary urethral cancer (PUC) is a very rare disease. This case report illustrates a successful treatment approach of a 67-year-old woman with a urethral adenocarcinoma selected for an organ preserving treatment with external beam radiotherapy (EBRT) and interstitial brachytherapy (BT) boost, using...

  11. Comparison of treatment using teletherapy (external beam radiation) alone versus teletherapy combined with brachytherapy for advanced squamous cell carcinoma of the esophagus

    International Nuclear Information System (INIS)

    Samea, Renato; Lourenco, Laercio Gomes

    2011-01-01

    Background - Squamous cell carcinoma of the esophagus is still a difficult tumor to treat with very poor prognosis. Aim - To compare the response to teletherapy treatment (external beam radiotherapy) alone versus teletherapy combined with brachytherapy for patients with advanced squamous cell carcinoma of the esophagus. Methods - Were studied 49 patients with advanced squamous cell carcinoma of the esophagus on clinical stage III (TNM-1999). They were separated into two groups. The first, underwent radiation therapy alone with linear accelerator of particles, average dose of 6000 cGy and the second to external beam radiation therapy at a dose of 5040 cGy combined with brachytherapy with Iridium 192 at a dose of 1500 cGy. Brachytherapy started one to two weeks after the end of teletherapy, and it was divided into three weekly applications of 500 cGy. Age, gender, race, habits (smoking and drinking), body mass index (BMI), complications with treatment benefits (pain relief and food satisfaction) and survival were analyzed. Results - The quality of life (food satisfaction, and pain palliation of dysphagia) were better in the group treated with external beam radiation therapy combined with brachytherapy. Survival was higher in the brachytherapy combined with external beam radiation therapy alone. Conclusion - Although the cure rate of squamous cell cancer of the esophagus is almost nil when treated with irradiation alone, this therapy is a form of palliative treatment for most patients in whom surgical contraindication exists. (author)

  12. Comparison of treatment using teletherapy (external beam radiation) alone versus teletherapy combined with brachytherapy for advanced squamous cell carcinoma of the esophagus

    Energy Technology Data Exchange (ETDEWEB)

    Samea, Renato; Lourenco, Laercio Gomes, E-mail: renatosamea@globo.com [Department of Surgical Oncology of Dr. Arnaldo Vieira de Carvalho Hospital, Sao Paulo, SP (Brazil)

    2011-10-15

    Background - Squamous cell carcinoma of the esophagus is still a difficult tumor to treat with very poor prognosis. Aim - To compare the response to teletherapy treatment (external beam radiotherapy) alone versus teletherapy combined with brachytherapy for patients with advanced squamous cell carcinoma of the esophagus. Methods - Were studied 49 patients with advanced squamous cell carcinoma of the esophagus on clinical stage III (TNM-1999). They were separated into two groups. The first, underwent radiation therapy alone with linear accelerator of particles, average dose of 6000 cGy and the second to external beam radiation therapy at a dose of 5040 cGy combined with brachytherapy with Iridium 192 at a dose of 1500 cGy. Brachytherapy started one to two weeks after the end of teletherapy, and it was divided into three weekly applications of 500 cGy. Age, gender, race, habits (smoking and drinking), body mass index (BMI), complications with treatment benefits (pain relief and food satisfaction) and survival were analyzed. Results - The quality of life (food satisfaction, and pain palliation of dysphagia) were better in the group treated with external beam radiation therapy combined with brachytherapy. Survival was higher in the brachytherapy combined with external beam radiation therapy alone. Conclusion - Although the cure rate of squamous cell cancer of the esophagus is almost nil when treated with irradiation alone, this therapy is a form of palliative treatment for most patients in whom surgical contraindication exists. (author)

  13. A comparison in cosmetic outcome between per-operative interstitial breast implants and delayed interstitial breast implants after external beam radiotherapy

    NARCIS (Netherlands)

    Pieters, Bradley R.; Hart, Augustinus A. M.; Russell, Nicola S.; Jansen, Edwin P. M.; Peterse, Johannes L.; Borger, Jacques; Rutgers, Emiel J. Th

    2003-01-01

    Background and purpose: Interstitial implants for brachytherapy boost in the breast conserving therapy of breast cancer can be performed in two ways; implants during the tumor excision (per-operative implants) or after the external beam therapy (delayed interstitial implants). Differences in

  14. Low grade gliomas: preliminary analysis of failure patterns among patients treated using 3D conformal external beam irradiation

    International Nuclear Information System (INIS)

    Pu, Anthony T.; Sandler, Howard M.; Radany, Eric H.; Blaivas, Mila; Page, Michaelyn A.; Greenberg, Harry S.; Junck, Larry; Ross, Donald A.

    1995-01-01

    Purpose: The pattern of failure of low grade gliomas following radiotherapy is less well known than that of the high grade gliomas. Stereotactic histologic studies have suggested that tumor cells extend beyond imaging abnormalities, and that large margins would be required for radiotherapy target volumes to encompass all of the neoplasm. Our experience using computerized tomography (CT)- and magnetic resonance (MR)-planned irradiation of low grade gliomas was reviewed to determine the pattern of tumor recurrence, in an effort to clinically define the minimum margin required. Methods and Materials: Forty-six patients with low grade supratentorial gliomas were treated between April 1985 and November 1992 using three-dimensional (3D) conformal CT- or MR-planned external beam radiotherapy. Fields were designed to encompass a target volume created by adding a margin to the tumor in three dimensions. Generally, patients were treated using shrinking fields with an initial target (tumor plus a 1 to 3 cm margin) treated to a dose of 45 to 50.4 (median 50.4) Gy, and a boost (tumor plus a 0 to 2 cm margin) treated to a total of 54 to 59.4 (median 59.4) Gy. Median follow-up was 32.9 months. Results: There have been 11 failures; all of these occurred within the radiographic abnormality (either T2 prolongation or CT hypodensity) visualized at the time of treatment planning (i.e., all failures were within the boost volume). Median time to failure was 53 months. Because all failures were local, there was no relationship between the amount by which the tumor volumes were expanded to create target volumes and the eventual outcome. Conclusion: Despite pathologic data suggesting that low grade glioma cells can be found outside the MR T2-signal abnormality in many cases, our results demonstrate that conformal external beam radiotherapy, in which the high dose volume is limited, does not result in increased marginal or out-of-field failures. Until control of tumor within the

  15. Muscle invasive bladder cancer treated by transurethral resection, followed by external beam radiation and interstitial iridium-192

    International Nuclear Information System (INIS)

    Wijnmaalen, Arendjan; Helle, Peter A.; Koper, Peter C.M.; Jansen, Peter P.; Hanssens, Patrick E.J.; Boeken Kruger, Cornelis G.G.; Putten, Wim L.J. van

    1996-01-01

    Purpose: In our center interstitial radiation has played an important role in the treatment of bladder cancer patients for over 40 years. Radium needles, that were initially used, were replaced by caesium needles in 1983, whereas the afterloading iridium wire technique was adopted in 1989. Patients with solitary tumors (T1, T2 and T3) with a surface diameter of < 5 cm are considered for interstitial radiation. In this study we report on the results of the afterloading iridium wire technique in patients with muscle invasive bladder cancer. Materials and Methods: From May 1989 to September 1993 interstitial radiation using iridium wires was part of the treatment in 46 patients with muscle invasive bladder cancer (37 T2, 9 T3). The mean age was 67 years. After transurethral resection of all visible tumor (if possible), in most cases 40 Gy (20 x 2.0 Gy, midplane dose) external beam radiation was delivered to the true pelvis, followed by 30 Gy interstitial radiation using iridium-192 wires covering the tumor area in the bladder. Results: After a median follow-up of 26 months, bladder relapses occurred in 7 patients. In 5 of them the tumor relapsed in the initial area, in 1 patient elsewhere in the bladder and in 1 patient tumor recurred in and outside the initial site. Recurrence was superficial (T1) in 4 patients. A relapse in the urethra was found once. Metastases developed in 13 patients, in 8 without bladder relapse. During the observation period 17 patients died, 13 due to bladder cancer. The actuarial bladder relapse-free survival at 4 years was 74% and 82% for T2 and T3 tumors, respectively. The actuarial distant metastases-free survival was 65% for both categories. No serious toxicity was recorded. Conclusion: In a selected group of patients with muscle invasive bladder cancer transurethral resection in combination with external beam and interstitial radiation provides an excellent opportunity to preserve the bladder with a high chance of success. Development of

  16. Prevalence and Predicting Factors for Commonly Neglected Sexual Side Effects to External-Beam Radiation Therapy for Prostate Cancer.

    Science.gov (United States)

    Frey, Anders; Pedersen, Christian; Lindberg, Henriette; Bisbjerg, Rasmus; Sønksen, Jens; Fode, Mikkel

    2017-04-01

    Changes in sexual function other than erectile dysfunction are sparsely investigated after radiation therapy for prostate cancer. To investigate orgasmic dysfunction, urinary incontinence during sexual activity, changes in penile morphology, and sensory disturbances in the penis in patients with prostate cancer treated with external-beam radiation therapy (EBRT). In February 2015, men treated with EBRT at our center 3 months to 5 years previously (N = 519) received a study-specific questionnaire. This was developed from purpose-built questions and validated tools including the Erection Hardness Scale. All patients had received a radiation dose of 78 Gy. Androgen deprivation therapy was administered according to disease characteristics. Outcome measurements were prevalence rates and predictors of these side effects as identified by multivariate logistic regression analyses. One hundred nine patients were eligible (sexually active and had completed androgen deprivation therapy) for inclusion. Twenty-four percent reported anorgasmia, 44% reported a decreased intensity of their orgasms, and 40% reported that the time it took to reach orgasm had increased. Eleven percent reported anejaculation. Fifteen percent reported orgasm-associated pain. Only 4% reported urinary incontinence during sexual activity. Subjective penile length loss in excess of 1 cm was reported by 42%. Twelve percent reported an altered curvature of their penis after EBRT. Six percent reported painful erections. Twenty-seven percent reported decreased sensitivity in the penis after EBRT, 2% reported a cold sensation, and 2% reported paresthesia. Increasing time since final treatment increased the risk of penile sensory disturbances (odds ratio = 1.05; P = .028). Orgasmic dysfunction, changes in penile morphology, and sensory disturbances in the penis are common side effects of ERBT. Patients should be properly informed of the occurrence of these side effects before deciding which treatment to

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

    Science.gov (United States)

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

    2015-09-01

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

  18. SU-E-T-66: A Prototype for Couch Based Real-Time Dosimetry in External Beam Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, P [Peter MacCallum Cancer Centre, Bendigo (Australia)

    2015-06-15

    Purpose: The main purpose of this study is to design a prototype for couch-based based real time dosimetry system in external beam radiotherapy Methods: A prototype of 100 ionization chambers was designed on a printed circuit board by etching the copper layer and each ionization chamber was wired to a 50 pin connector. The signals from the two 50 pin connectors collected from the ionization chambers were then transferred to a PXI module from National Instruments. The PXI module houses a current amplifier that amplifies the charge collected from the ionization chamber. The amplified signal is then sent to a digital multimeter module for converting the analog signal to digital signal. A software was designed in labview to read and display the signals obtained from the PXI module. A couch attachment frame was designed to house the 100 ionization chamber module. The frame was fixed underneath the treatment couch for measuring the dose during treatment. Resutls: The ionization chamber based prototype dosimetry was tested for simple radiotherapy treatment fields and found to be a useful device for measuring real time dosimetry at the treatment couch plane. This information could be used to assess the delivered dose to a patient during radiotherapy. It could be used as an invivo dosimeter during radiotherapy. Conclusion: In this study, a prototype for couch based real time dosimetry system was designed and tested. The prototype forms a basis for the development of large scale couch based real time dosimetry system that could be used to perform morning QA prior to treatment, assess real time doses delivered to patient and as a device to monitor the output of the treatment beam. Peter MacCallum Cancer Foundation.

  19. SU-E-T-66: A Prototype for Couch Based Real-Time Dosimetry in External Beam Radiotherapy

    International Nuclear Information System (INIS)

    Ramachandran, P

    2015-01-01

    Purpose: The main purpose of this study is to design a prototype for couch-based based real time dosimetry system in external beam radiotherapy Methods: A prototype of 100 ionization chambers was designed on a printed circuit board by etching the copper layer and each ionization chamber was wired to a 50 pin connector. The signals from the two 50 pin connectors collected from the ionization chambers were then transferred to a PXI module from National Instruments. The PXI module houses a current amplifier that amplifies the charge collected from the ionization chamber. The amplified signal is then sent to a digital multimeter module for converting the analog signal to digital signal. A software was designed in labview to read and display the signals obtained from the PXI module. A couch attachment frame was designed to house the 100 ionization chamber module. The frame was fixed underneath the treatment couch for measuring the dose during treatment. Resutls: The ionization chamber based prototype dosimetry was tested for simple radiotherapy treatment fields and found to be a useful device for measuring real time dosimetry at the treatment couch plane. This information could be used to assess the delivered dose to a patient during radiotherapy. It could be used as an invivo dosimeter during radiotherapy. Conclusion: In this study, a prototype for couch based real time dosimetry system was designed and tested. The prototype forms a basis for the development of large scale couch based real time dosimetry system that could be used to perform morning QA prior to treatment, assess real time doses delivered to patient and as a device to monitor the output of the treatment beam. Peter MacCallum Cancer Foundation

  20. External Beam Radiotherapy for Focal Lymphoepithelioma-Like Carcinoma in the Urinary Bladder: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Nobuhiro Kushida

    2015-01-01

    Full Text Available Lymphoepithelioma is a malignant epithelial tumor in the nasopharynx characterized by prominent lymphoid infiltration. Carcinomas that resemble lymphoepitheliomas have been called lymphoepithelioma-like carcinomas and have been reported in other organs. A tumor in the bladder is categorized by the percentage of the total area occupied by the lymphoepithelioma-like carcinoma pattern, with the prognosis dependent on the percentage. We present an 81-year-old man with stage 3 chronic obstructive pulmonary disease and a history of aortic aneurysm repair. The computed tomography scans indicated thickening and irregularity of the bladder wall, with left external iliac lymph node metastasis. His diagnosis was bladder cancer, and the clinical stage was evaluated as T3N1M0. Transurethral resection of the bladder tumor was performed, and the pathological specimen showed that the tumor was composed of undifferentiated malignant cells with sheets and nests arranged in a syncytial pattern, as well as an urothelial carcinoma lesion. A prominent lymphoid reaction accompanied the tumor. The pathological diagnosis was focal-type lymphoepithelioma-like carcinoma containing a component of urothelial carcinoma G3>G2. His general condition was such that he could not tolerate radical cystectomy or systemic chemotherapy. External beam radiotherapy (total 60 Gy was given to the bladder, including the lymph node metastatic lesion. No cancer recurrence was detected by regular follow-up computed tomography and cystoscopy. He eventually died of other causes 48 months later. Although treatment for focal lymphoepithelioma-like carcinoma generally requires multifocal therapies, in the present case, the bladder became tumor free. We also summarize previously reported lymphoepithelioma-like carcinoma cases treated with radiotherapy.

  1. Nonlinear dynamics and chaotization of oscillations of a virtual cathode in an annular electron beam in a uniform external magnetic field

    International Nuclear Information System (INIS)

    Kurkin, S. A.; Koronovski, A. A.; Hramov, A. E.

    2009-01-01

    Results are presented from a numerical study of the effect of an external magnetic field on the conditions and mechanisms for the formation of a virtual cathode in a relativistic electron beam. Characteristic features of the nonlinear dynamics of an electron beam with a virtual cathode are considered when the external magnetic field is varied. Various mechanisms are investigated by which the virtual cathode oscillations become chaotic and their spectrum becomes a multifrequency spectrum, thereby complicating the dynamics of the vircator system. A general mechanism for chaotization of the oscillations of a virtual cathode in a vircator system is revealed: the electron structures that form in an electron beam interact by means of a common space charge field to give rise to additional internal feedback. That the oscillations of a virtual cathode change from the chaotic to the periodic regime is due to the suppression of the mechanism for forming secondary electron structures.

  2. TU-D-201-03: Results of a Survey On the Implementation of the TG-51 Protocol and Associated Addendum On Reference Dosimetry of External Beams

    Energy Technology Data Exchange (ETDEWEB)

    Kim, G [University of California, San Diego, La Jolla, CA (United States); Muir, B [National Research Council, Ottawa, AB (Canada); Culberson, W [University of Wisconsin Madison, Madison, WI (United States); Davis, S [McGill University Health Center, Montreal, QC (Canada); Huang, Y [Henry Ford Health System, West Bloomfield, MI (United States); Lee, S [University of Maryland School of Medicine, Columbia, MD (United States); Lowenstein, J [UT MD Anderson Cancer Center, Houston, TX (United States); Sarfehnia, A [Sunnybrook Health Science Center, Toronto, ON (Canada); Tolani, N [Michael E. DeBakey VA Medical Center, Sugarland (United States); Siebers, J [University of Virginia Health System, Charlottesville, VA (United States)

    2016-06-15

    Purpose: The working group on the review and extension of the TG-51 protocol (WGTG51) collected data from American Association of Physicists in Medicine (AAPM) members with respect to their current TG-51 and associated addendum usage in the interest of considering future protocol addenda and guidance on reference dosimetry best practices. This study reports an overview of this survey on dosimetry of external beams. Methods: Fourteen survey questions were developed by WGTG51 and released in November 2015. The questions collected information on reference dosimetry, beam quality specification, and ancillary calibration equipment. Results: Of the 190 submissions completed worldwide (U.S. 70%), 83% were AAPM members. Of the respondents, 33.5% implemented the TG-51 addendum, with the maximum calibration difference for any photon beam, with respect to the original TG-51 protocol, being <1% for 97.4% of responses. One major finding is that 81.8% of respondents used the same cylindrical ionization chamber for photon and electron dosimetry, implying that many clinics are foregoing the use of parallel-plate chambers. Other evidence suggests equivalent dosimetric results can be obtained with both cylindrical and parallel-plate chambers in electron beams. This, combined with users comfort with cylindrical chambers for electrons will likely impact recommendations put forward in an upcoming electron beam addendum to the TG-51 protocol. Data collected on ancillary equipment showed 58.2% (45.0%) of the thermometers (barometers) in use for beam calibration had NIST traceable calibration certificates, but 48.4% (42.7%) were never recalibrated. Conclusion: This survey provides a snapshot of TG-51 external beam reference dosimetry practice in radiotherapy centers. Findings demonstrate the rapid take-up of the TG-51 photon beam addendum and raise issues for the WGTG51 to focus on going forward, including guidelines on ancillary equipment and the choice of chamber for electron beam

  3. Tolerance doses of cutaneous and mucosal tissues in ring-necked parakeets (Psittacula krameri) for external beam megavoltage radiation.

    Science.gov (United States)

    Barron, Heather W; Roberts, Royce E; Latimer, Kenneth S; Hernandez-Divers, Stephen; Northrup, Nicole C

    2009-03-01

    Currently used dosages for external-beam megavoltage radiation therapy in birds have been extrapolated from mammalian patients and often appear to provide inadequate doses of radiation for effective tumor control. To determine the tolerance doses of cutaneous and mucosal tissues of normal birds in order to provide more effective radiation treatment for tumors that have been shown to be radiation responsive in other species, ingluvial mucosa and the skin over the ingluvies of 9 ring-necked parakeets (Psittacula krameri) were irradiated in 4-Gy fractions to a total dose of either 48, 60, or 72 Gy using an isocentric cobalt-60 teletherapy unit. Minimal radiation-induced epidermal changes were present in the high-dose group histologically. Neither dose-related acute nor chronic radiation effects could be detected in any group grossly in cutaneous or mucosal tissue over a 9-month period. Radiation doses of 72 Gy in 4-Gy fractions were well tolerated in the small number of ring-necked parakeets in this initial tolerance dose study.

  4. Current External Beam Radiation Therapy Quality Assurance Guidance: Does It Meet the Challenges of Emerging Image-Guided Technologies?

    International Nuclear Information System (INIS)

    Palta, Jatinder R.; Liu, Chihray; Li, Jonathan G.

    2008-01-01

    The traditional prescriptive quality assurance (QA) programs that attempt to ensure the safety and reliability of traditional external beam radiation therapy are limited in their applicability to such advanced radiation therapy techniques as three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, inverse treatment planning, stereotactic radiosurgery/radiotherapy, and image-guided radiation therapy. The conventional QA paradigm, illustrated by the American Association of Physicists in Medicine Radiation Therapy Committee Task Group 40 (TG-40) report, consists of developing a consensus menu of tests and device performance specifications from a generic process model that is assumed to apply to all clinical applications of the device. The complexity, variation in practice patterns, and level of automation of high-technology radiotherapy renders this 'one-size-fits-all' prescriptive QA paradigm ineffective or cost prohibitive if the high-probability error pathways of all possible clinical applications of the device are to be covered. The current approaches to developing comprehensive prescriptive QA protocols can be prohibitively time consuming and cost ineffective and may sometimes fail to adequately safeguard patients. It therefore is important to evaluate more formal error mitigation and process analysis methods of industrial engineering to more optimally focus available QA resources on process components that have a significant likelihood of compromising patient safety or treatment outcomes

  5. Three-dimensional intrafractional internal target motions in accelerated partial breast irradiation using three-dimensional conformal external beam radiotherapy.

    Science.gov (United States)

    Hirata, Kimiko; Yoshimura, Michio; Mukumoto, Nobutaka; Nakamura, Mitsuhiro; Inoue, Minoru; Sasaki, Makoto; Fujimoto, Takahiro; Yano, Shinsuke; Nakata, Manabu; Mizowaki, Takashi; Hiraoka, Masahiro

    2017-07-01

    We evaluated three-dimensional intrafractional target motion, divided into respiratory-induced motion and baseline drift, in accelerated partial breast irradiation (APBI). Paired fluoroscopic images were acquired simultaneously using orthogonal kV X-ray imaging systems at pre- and post-treatment for 23 patients who underwent APBI with external beam radiotherapy. The internal target motion was calculated from the surgical clips placed around the tumour cavity. The peak-to-peak respiratory-induced motions ranged from 0.6 to 1.5mm in all directions. A systematic baseline drift of 1.5mm towards the posterior direction and a random baseline drift of 0.3mm in the lateral-medial and cranial-caudal directions were observed. The baseline for an outer tumour cavity drifted towards the lateral and posterior directions, and that for an upper tumour cavity drifted towards the cranial direction. Moderate correlations were observed between the posterior baseline drift and the patients' physical characteristics. The posterior margin for intrafractional uncertainties was larger than 5mm in patients with greater fat thickness due to the baseline drift. The magnitude of the intrafractional motion was not uniform according to the direction, patients' physical characteristics, or tumour cavity location due to the baseline drift. Therefore, the intrafractional systematic movement should be properly managed. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

    Jacinto, Alexandre A; Maia, Maria AC; Fogaroli, Ricardo C; Castilho, Marcus S; Novaes, Paulo ERS; Novick, Pablo R; Viani, Gustavo A; Salvajoli, João V; Ferrigno, Robson; Pellizzon, Antonio Cássio A; Lima, Stella SS

    2007-01-01

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

  7. Photochemical Internalization of Bleomycin Before External-Beam Radiotherapy Improves Locoregional Control in a Human Sarcoma Model

    International Nuclear Information System (INIS)

    Norum, Ole-Jacob; Bruland, Oyvind Sverre; Gorunova, Ludmila; Berg, Kristian

    2009-01-01

    Purpose: The aim of this study was to explore the tumor growth response of the combination photochemical internalization and external-beam radiotherapy. Photochemical internalization is a technology to improve the utilization of therapeutic macromolecules in cancer therapy by photochemical release of endocytosed macromolecules into the cytosol. Methods and Materials: A human sarcoma xenograft TAX-1 was inoculated subcutaneously into nude mice. The photosensitizer AlPcS 2a and bleomycin were intraperitoneally administrated 48 h and 30 min, respectively, before diode laser light exposure at 670 nm (20 J/cm 2 ). Thirty minutes or 7 days after photochemical treatment, the animals were subjected to 4 Gy of ionizing radiation. Results: Using photochemical internalization of bleomycin as an adjunct to ionizing radiation increased the time to progression for the tumors from 17 to 33 days as compared with that observed with photodynamic therapy combined with ionizing radiation as well as for radiochemotherapy with bleomycin. The side effects observed when photochemical internalization of bleomycin was given shortly before ionizing radiation were eliminated by separating the treatment modalities in time. Conclusion: Photochemical internalization of bleomycin combined with ionizing radiation increased the time to progression and showed minimal toxicity and may therefore reduce the total radiation dose necessary to obtain local tumor control while avoiding long-term sequelae from radiotherapy.

  8. The effect of external beam radiotherapy volume on locoregional control in patients with locoregionally advanced or recurrent nonanaplastic thyroid cancer

    International Nuclear Information System (INIS)

    Kim, Tae Hyun; Kim, Sang Soo; Cho, Kwan Ho; Shin, Kyung Hwan; Chung, Ki-Wook; Lee, You Jin; Park, Chan Sung; Lee, Eun Kyung; Kim, Tae Sung; Kim, Seok Ki; Jung, Yoo Seok; Ryu, Jun Sun

    2010-01-01

    We evaluated outcomes of patients treated with external beam radiotherapy (EBRT) for locoregionally advanced or recurrent nonanaplastic thyroid cancer and analyzed the effect of EBRT volume on locoregional control. This study included 23 patients with locoregionally advanced or recurrent nonanaplastic thyroid cancer who were treated with EBRT. Two different EBRT target volumes were executed as follows: 1) limited field (LF, n = 11) included the primary (involved lobe) or recurrent tumor bed and the positive nodal area; 2) elective field (EF, n = 12) included the primary (involved lobe) or recurrent tumor bed and the regional nodal areas in the cervical neck and upper mediastinum. Clinical parameters, such as gender, age, histologic type, recurrence, stage, thyroglobulin level, postoperative residuum, radioiodine treatment, and EBRT volume were analyzed to identify prognostic factors associated with locoregional control. There were no significant differences in the clinical parameter distributions between the LF and EF groups. In the LF group, six (55%) patients developed locoregional recurrence and three (27%) developed distant metastasis. In the EF group, one (8%) patient developed locoregional recurrence and one (8%) developed a distant metastasis. There was a significant difference in locoregional control rate at 5 years in the LF and EF groups (40% vs. 89%, p = 0.041). There were no significant differences in incidences of acute and late toxicities between two groups (p >0.05). EBRT with EF provided significantly better locoregional control than that of LF; however, further larger scaled studies are warranted

  9. Risk of fatal cerebrovascular accidents after external beam radiation therapy for early-stage glottic laryngeal cancer.

    Science.gov (United States)

    Swisher-McClure, Samuel; Mitra, Nandita; Lin, Alexander; Ahn, Peter; Wan, Fei; O'Malley, Bert; Weinstein, Gregory S; Bekelman, Justin E

    2014-05-01

    This study compared the risk of fatal cerebrovascular accidents (CVAs) in patients with early-stage glottic laryngeal cancer receiving surgery or external beam radiation therapy (EBRT). Using a competing risks survival analysis, we compared the risk of death because of CVA among patients with early-stage glottic laryngeal cancer receiving surgery or EBRT in the Surveillance, Epidemiology, and End Results (SEER) database. The cumulative incidence of fatal CVA at 15 years was higher in patients receiving EBRT (2.8%; 95% confidence interval [CI], 2.3% to 3.4%) compared to surgery (1.5%; 95% CI, 0.8% to 2.3%; p = .024). In multivariable competing risks regression models, EBRT remained associated with an increased risk of fatal CVA compared to surgery (adjusted hazard ratio [HR], 1.75; 95% CI, 1.04-2.96; p = .037). Treatment for early-stage glottic laryngeal cancer with EBRT was associated with a small increase in the risk of late fatal CVA events relative to surgery. Copyright © 2013 Wiley Periodicals, Inc.

  10. Leaflet manual of external beam radiation therapy for hepatocellular carcinoma: a review of the indications, evidences, and clinical trials.

    Science.gov (United States)

    Rim, Chai Hong; Yoon, Won Sup

    2018-01-01

    The use of external beam radiation therapy (EBRT) in the treatment of hepatocellular carcinoma (HCC), which was rarely performed due to liver toxicity with a previous technique, has increased. Palliation of portal vein thrombosis, supplementation for insufficient transarterial chemoembolization, and provision of new curative opportunities using stereotactic body radiotherapy are the potential indications for use of EBRT. The mechanism of EBRT treatment, with its radiobiological and physical perspectives, differs from those of conventional medical treatment or surgery. Therefore, understanding the effects of EBRT may be unfamiliar to physicians other than radiation oncologists, especially in the field of HCC, where EBRT has recently begun to be applied. The first objective of this review was to concisely explain the indications for use of EBRT for HCC for all physicians treating HCC. Therefore, this review focuses on the therapeutic outcomes rather than the detailed biological and physical background. We also reviewed recent clinical trials that may extend the indications for use of EBRT. Finally, we reviewed the current clinical practice guidelines for the treatment of HCC and discuss the current recommendations and future perspectives.

  11. The management of carcinoma of the anal canal by external beam radiotherapy, experience in Vancouver 1971-1988

    International Nuclear Information System (INIS)

    Newman, G.; Calverley, D.C.; Acker, B.D.; Manji, M.; Hay, J.; Flores, A.D.

    1992-01-01

    From 1971 to 1988 72 cases of carcinoma of the anal canal were treated by external beam radiotherapy, most commonly by 5000 cGy in 20 fractions given over 4 weeks. The actuarial survival at 5 years was 66% and the disease specific survival 78%. Nine patients had inguinal node metastases at diagnosis; their 5-year disease specific survival was 75%. 63 Patients were inguinal node negative at presentation; their 5-year specific survival was 78%, by UICC 1987 staging: T 1 71%, T 2 88%, T 3 41%, T 4 42%. 17 Patients developed local recurrence; 10 were suitable for abdominoperineal resection which was successful in 7. The probability of local control was related to T stage. 13 patients were left with a colostomy because of recurrence, 2 had a colostomy for radiation damage and 4 had their local recurrence managed palliatively, without a colostomy. As a result, 53 of the 72 patients (74%) were left with a functional anus. Severe late complications occurred in 6 (8%). (author). 13 refs., 3 figs., 7 tabs

  12. The management of carcinoma of the anal canal by external beam radiotherapy, experience in Vancouver 1971-1988

    Energy Technology Data Exchange (ETDEWEB)

    Newman, G. (Bristol Oncology Centre (United Kingdom)); Calverley, D.C.; Acker, B.D.; Manji, M.; Hay, J.; Flores, A.D. (British Columbia Cancer Inst., Vancouver, BC (Canada))

    1992-11-01

    From 1971 to 1988 72 cases of carcinoma of the anal canal were treated by external beam radiotherapy, most commonly by 5000 cGy in 20 fractions given over 4 weeks. The actuarial survival at 5 years was 66% and the disease specific survival 78%. Nine patients had inguinal node metastases at diagnosis; their 5-year disease specific survival was 75%. 63 Patients were inguinal node negative at presentation; their 5-year specific survival was 78%, by UICC 1987 staging: T[sub 1] 71%, T[sub 2] 88%, T[sub 3] 41%, T[sub 4] 42%. 17 Patients developed local recurrence; 10 were suitable for abdominoperineal resection which was successful in 7. The probability of local control was related to T stage. 13 patients were left with a colostomy because of recurrence, 2 had a colostomy for radiation damage and 4 had their local recurrence managed palliatively, without a colostomy. As a result, 53 of the 72 patients (74%) were left with a functional anus. Severe late complications occurred in 6 (8%). (author). 13 refs., 3 figs., 7 tabs.

  13. Prostate specific antigen levels during and after external beam radiotherapy for localized carcinoma of the prostate: Predictor of therapeutic efficancy

    International Nuclear Information System (INIS)

    Rodrigus, P.; Landeghem, A.A.J. van

    1992-01-01

    For 105 patients with locoregional carcinoma of the prostate, prostate specific antigen (PSA) levels were evaluated before, during and after external beam radiotherapy. The median follow-up is 17 months. In 51 patients (48.5%) initial PSA levels exceeded the maximum normal value of 20 ng/ml. Nine patients kept non-declining high levels just after radiotherapy. Only one of these is free of disease. Assuming PSA levels decrease exponentially during radiotherapy, a mean half-life of 62 days (median 54, SD 26 days) was calculated. Three out of five patients with a PSA half-life of more than 88 days relapsed as compared to a 8% (3/37) relapse rate in patients with a 'normal' half-life. Prolonged PSA half-life suggests residual disease. PSA levels are expected to further decrease after radiation. Six months after irradiation persistent high PSA levels were found in 14/51 (27.5%) patients. Only four of them had no evidence of manifest disease. Important negative prognostic factors for disease control in our series were non-declining high levels of PSA, a PSA serum half-life exceeding 88 days and persistence of elevated PSA values longer than six months after treatment. In our opinion, PSA is a valuable marker in the follow-up of prostate cancer patients during and after radiotherapy. (orig.) [de

  14. The importance of adequate follow-up in defining treatment success after external beam irradiation for prostate cancer

    International Nuclear Information System (INIS)

    Vicini, Frank A.; Kestin, Larry L.; Martinez, Alvaro A.

    1999-01-01

    Purpose: We reviewed our institution's experience treating patients with localized prostate cancer with external beam radiation therapy (RT) to determine how differences in the length of follow-up affect the determination of treatment outcome using the American Society for Therapeutic Radiology and Oncology (ASTRO) Consensus Panel Definition of biochemical failure (BF). Methods and Materials: From January 1987 through December 1997, 1109 patients with localized prostate cancer were treated with definitive external beam RT at William Beaumont Hospital, Royal Oak, Michigan. All patients received external beam RT to a median total prostate dose of 66.6 Gy (range: 59.4-70.4 Gy). A total of 1096 patients (99%) had sufficient prostate-specific antigen (PSA) follow-up to determine their biochemical status. To test the impact of differences in follow-up on the calculation of BF, 389 patients with at least 5 years of PSA follow-up were selected as the reference group for the initial analysis. BF was then retrospectively determined using the Consensus Panel definition at yearly intervals, ignoring the remainder of each patient's follow-up. The median follow-up for this group of patients was 6.6 years (range: 5.0-11.6 years). In a second analysis, patient cohorts were randomly selected with varying median PSA follow-up intervals in order to more accurately represent a population whose follow-up is distributed continuously over a defined range. Seven cohorts were randomly selected with 200 patients in each cohort. Cohorts were individually identified such that half of the patients (100) had 2 years or less follow-up than the stated time point for analysis and half (100) had up to 2 years more follow-up than the time point chosen for analysis. For example, in the cohort with a median follow-up of 3 years, 100 patients with a PSA follow-up from 1 to 3 years were randomly selected, and 100 patients with a follow-up from 3 to 5 years were randomly selected, thus generating a

  15. Study of Z > 18 elements concentration in tree rings from surroundings forests of the Mexico Valley using external beam PIXE

    International Nuclear Information System (INIS)

    Calva-Vazquez, G.; Razo-Angel, G.; Rodriguez-Fernandez, L.; Ruvalcaba-Sil, J.L.

    2006-01-01

    The concentration of elements with Z > 18 is measured in tree rings from forests at the surroundings of the Mexico Valley: El Chico National Park (ECP) and Desierto de los Leones National Park (DLP). The analysis was done by simultaneous PIXE-RBS using an external proton beam on tree rings of Pine and Sacred fir (species Pinus montezumae and Abies religiosa, respectively). This study provides information about the elemental concentration in trees of those parks during the years from 1965 to 2003. Typical elements such as K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr and Pb were detected using PIXE technique while the wood matrix composition (mainly C and O) was determined by RBS. In general, elemental contents present large variations but concentrations oscillate around the mean value during this period of time. Nevertheless, the measurements showed some trends for Fe and Zn in the tree-rings elemental composition that may be correlated to recent volcanic activities in the region. The low Mn contents indicate soil acidification in DLP from 1968 and the forest decline in ECP during the last 15 years

  16. Brief Report: External Beam Radiation Therapy for the Treatment of Human Pluripotent Stem Cell-Derived Teratomas.

    Science.gov (United States)

    Lee, Andrew S; Tang, Chad; Hong, Wan Xing; Park, Sujin; Bazalova-Carter, Magdalena; Nelson, Geoff; Sanchez-Freire, Veronica; Bakerman, Isaac; Zhang, Wendy; Neofytou, Evgenios; Connolly, Andrew J; Chan, Charles K; Graves, Edward E; Weissman, Irving L; Nguyen, Patricia K; Wu, Joseph C

    2017-08-01

    Human pluripotent stem cells, including human embryonic stem cells (hESCs) and human induced PSCs (hiPSCs), have great potential as an unlimited donor source for cell-based therapeutics. The risk of teratoma formation from residual undifferentiated cells, however, remains a critical barrier to the clinical application of these cells. Herein, we describe external beam radiation therapy (EBRT) as an attractive option for the treatment of this iatrogenic growth. We present evidence that EBRT is effective in arresting growth of hESC-derived teratomas in vivo at day 28 post-implantation by using a microCT irradiator capable of targeted treatment in small animals. Within several days of irradiation, teratomas derived from injection of undifferentiated hESCs and hiPSCs demonstrated complete growth arrest lasting several months. In addition, EBRT reduced reseeding potential of teratoma cells during serial transplantation experiments, requiring irradiated teratomas to be seeded at 1 × 10 3 higher doses to form new teratomas. We demonstrate that irradiation induces teratoma cell apoptosis, senescence, and growth arrest, similar to established radiobiology mechanisms. Taken together, these results provide proof of concept for the use of EBRT in the treatment of existing teratomas and highlight a strategy to increase the safety of stem cell-based therapies. Stem Cells 2017;35:1994-2000. © 2017 AlphaMed Press.

  17. Use of 3D printers to create a patient‐specific 3D bolus for external beam therapy

    Science.gov (United States)

    Baker, Jamie; Hsia, An Ting; Xu, Zhigang

    2015-01-01

    The purpose of this paper is to demonstrate that an inexpensive 3D printer can be used to manufacture patient‐specific bolus for external beam therapy, and to show we can accurately model this printed bolus in our treatment planning system for accurate treatment delivery. Percent depth‐dose measurements and tissue maximum ratios were used to determine the characteristics of the printing materials, acrylonitrile butadiene styrene and polylactic acid, as bolus material with physical density of 1.04 and 1.2 g/cm3, and electron density of 3.38×1023electrons/cm3 and 3.80×1023 electrons/cm3, respectively. Dose plane comparisons using Gafchromic EBT2 film and the RANDO phantom were used to verify accurate treatment planning. We accurately modeled a printing material in Eclipse treatment planning system, assigning it a Hounsfield unit of 260. We were also able to verify accurate treatment planning using gamma analysis for dose plane comparisons. With gamma criteria of 5% dose difference and 2 mm DTA, we were able to have 86.5% points passing, and with gamma criteria of 5% dose difference and 3 mm DTA, we were able to have 95% points passing. We were able to create a patient‐specific bolus using an inexpensive 3D printer and model it in our treatment planning system for accurate treatment delivery. PACS numbers: 87.53.Jw, 87.53.Kn, 87.56.ng PMID:26103485

  18. Early effect of external beam radiation therapy on the anal sphincter: A study using anal manometry and transrectal ultrasound

    International Nuclear Information System (INIS)

    Birnbaum, E.H.; Dreznik, Z.; Myerson, R.J.; Lacey, D.L.; Fry, R.D.; Kodner, I.J.; Fleshman, J.W.

    1992-01-01

    The early of pelvic irradiation on the anal sphincter has not been previously investigated. This study prospectively evaluated the acute effect of preoperative radiation on anal function. Twenty patients with rectal carcinoma received 4,500 cGy of preoperative external beam radiation. The field of radiation included the sphincter in 10 patients and was delivered above the anorectal ring in 10 patients. Anal manometry and transrectal ultrasound were performed before and four weeks after radiotherapy. No significant difference in mean maximal squeeze or resting pressure was found after radiation therapy. An increase in mean minimal sensory threshold was significant. Histologic examination revealed minimal radiation changes at the distal margin in 8 of 10 patients who underwent low anterior resection and in 1 of 3 patients who underwent abdominoperineal resection. The authors conclude that preoperative radiation therapy has minimal immediate effect on the anal sphincter and is not a major contributing factor to postoperative incontinence in patients after sphincter-saving operations for rectal cancer

  19. Comparison between external beam radiotherapy (70 Gy/74 Gy) and permanent interstitial brachytherapy in 890 intermediate risk prostate cancer patients

    International Nuclear Information System (INIS)

    Goldner, Gregor; Pötter, Richard; Battermann, Jan J.; Kirisits, Christian; Schmid, Maximilian P.; Sljivic, Samir; Vulpen, Marco van

    2012-01-01

    Purpose: Aim of this analysis was to compare biochemical no evidence of disease (bNED) rates in intermediate-risk prostate-cancer patients treated at two centres of excellence using different approaches: permanent interstitial brachytherapy (BT) and external beam radiotherapy (EBRT). Materials and methods: A total of 890 intermediate-risk prostate-cancer patients, who were treated from 1998 to 2008, were identified in the two local databases. In Utrecht 601 patients received I-125 BT applying a dose of 144 Gy. In Vienna 289 patients were treated by EBRT, applying a local dose of 70 Gy in 105 patients and 74 Gy in 184 patients. bNED-rates (Phoenix-definition) were assessed. Results: Median follow-up was 48 months (1–150). 5-Year actuarial bNED-rates were 81% for BT-patients and 75% for EBRT-patients (67% for 70 Gy and 82% for 74 Gy), respectively. In univariate analysis no difference between BT and EBRT could be detected. In multivariate analysis including tumour-stage, GleasonScore, initial PSA, hormonal therapy and treatment-centre (BT vs. EBRT) only T-stage, GleasonScore and PSA were found to be significant. Additional analysis including radiation dose showed the same outcome. Conclusions: Intermediate-risk prostate cancer patients treated by permanent interstitial brachytherapy show biochemical tumour-control-rates which are comparable to EBRT of 74 Gy.

  20. Pattern of failures in gastric cancer patients with lymph node involvement treated by surgery, intraoperative and external beam radiotherapy

    International Nuclear Information System (INIS)

    Glehen, O.; Peyrat, P.; Beaujard, A.C.; Chapet, O.; Romestaing, P.; Sentenac, I.; Francois, Y.; Vignal, J.; Gerard, J.P.; Gilly, F.N.

    2003-01-01

    Aims: High local failure rates in gastric cancer have been reported, up to 67%. To achieve a better local control, we evaluated intraoperative radiotherapy (IORT) and external beam radiotherapy (EBRT) in association with surgery for gastric cancer patients with lymph node involvement. We report here the analysis of the patterns of failure for patients involved in this IORT protocol. Material and methods: Forty-two positive lymph node (N+) gastric cancer patients were operated on (31 total, three subtotal and eight extended gastrectomies) with IORT procedure between 1985 and 1997 (33 males, nine females, mean age 61.3 years). IORT was focused on coeliac area (mean dose 15 Gy), followed by EBRT (46 Gy) in 36 patients. Ten patients were pN1 and 32 were pN2. A concurrent systemic chemotherapy (five Fluoro-Uracil and Cisplatinum) was performed in 14 patients. Results: One patient died postoperatively. Actuarial pN+ 10 year survival rate was 44.8%. The 5 year actuarial local control and disease-free survival rates were 78.8 and 47.5%, respectively. As far as patterns of failure were explored, 5 patients have a local coeliac recurrence (12%) and 12 have distant metastases with no evidence of coeliac recurrence. Conclusion: This retrospective analysis suggests a potential effect of IORT and/or EBRT in promoting local control and long-term survival in gastric cancer patients with lymph node involvement

  1. The upgraded external-beam PIXE/PIGE set-up at LABEC for very fast measurements on aerosol samples

    Energy Technology Data Exchange (ETDEWEB)

    Lucarelli, F., E-mail: lucarelli@fi.infn.it; Calzolai, G.; Chiari, M.; Giannoni, M.; Mochi, D.; Nava, S.; Carraresi, L.

    2014-01-01

    At the 3 MV Tandetron accelerator of the LABEC laboratory of INFN in Florence, an external beam facility is fully dedicated to measurements of elemental composition of atmospheric aerosol. The experimental set-up hitherto used for this kind of applications has been upgraded with the replacement of a traditional Si(Li) detector for the detection of medium–high Z elements with a silicon drift detector (SDD) with a big active area (80 mm{sup 2}) and 450 μm thickness, with the aim of obtaining better minimum detection limits (MDL) and reduce measuring times. The Upilex extraction window has been replaced by a more resistant one (Si{sub 3}N{sub 4}). A comparison between the old Si(Li) and the new SDD for aerosol samples collected on different substrata like Teflon, Kapton and Nuclepore evidenced the better performances of the SDD. It allows obtaining better results (higher counting statistics, lower MDLs) even in shorter measuring times, thus allowing very fast analysis of both daily and hourly samples.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-15

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

  3. The upgraded external-beam PIXE/PIGE set-up at LABEC for very fast measurements on aerosol samples

    Energy Technology Data Exchange (ETDEWEB)

    Lucarelli, F.; Calzolai, G.; Chiari, M.; Mochi, D.; Nava, S. [Department of Physics, University of Florence and INFN, Florence (Italy)

    2013-07-01

    Full text: Particle Induced X-ray Emission (PIXE)technique has been widely used since its birth for the study of the aerosol composition, and for a long time it has been the dominating technique for its elemental analysis. However now it has to compete with other techniques, like Induced Coupled Plasma and detection by Atomic Emission Spectroscopy (ICP-AES) or Mass Spectrometry (ICP-MS) or Synchrotron Radiation XRF (SR-XRF). To remain competitive, a proper experimental set-up is important to fully exploit PIXE capabilities. At LABEC, an external beam line is fully dedicated to PIXE-PIGE measurements of atmospheric aerosols [1]. Recently SDD (Silicon Drift Detectors) have been introduced for X-ray detection thanks to their better resolution with respect to Si(Li) detectors and the possibility of managing high counting rates (up to 50 kHz at 0.5 μsec shaping time). This implies, in turn, the possibility of using very high beam currents thus drastically reducing the measurement time. However their use for a complete characterization of X-rays was limited by the small thickness and surface areas available. Now SDD with a thickness of 500 μm and 80 mm{sup 2} area have been introduced in the market. We have therefore replaced the Si(Li) detector used so far for the detection of medium-high Z elements with such a SDD. A comparison of the two detectors has been carried out; PIXE minimum detection limits (MDLs) at different proton beam energies have been studied to find out the best energy for PIXE measurements on aerosol samples collected on different substrata, namely Teflon, Kapton, Nuclepore and Kimfol, used for daily or hourly sampling or for cascade impactors. In particular in the case of Teflon filters, the production of γ-rays by F in the Teflon filter limits the current which may be used and the Compton γ-ray background worsens the MDLs. Due to the lower thickness of the SDD detector with respect to a typical Si(Li) detector, these problems are reduced

  4. Adjuvant radiotherapy following radical hysterectomy for patients with stage IB and IIA cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Soisson, A.P.; Soper, J.T.; Clarke-Pearson, D.L.; Berchuck, A.; Montana, G.; Creasman, W.T. (Duke Univ. Medical Center, Durham, NC (USA))

    1990-06-01

    From 1971 through 1984, 320 women underwent radical hysterectomy as primary therapy of stage IB and IIA cervical cancer. Two hundred forty-eight patients (78%) were treated with surgery alone and 72 patients (22%) received adjuvant postoperative external-beam radiotherapy. Presence of lymph node metastasis, large lesion (greater than 4 cm in diameter), histologic grade, race (noncaucasian), and age (greater than 40 years) were significant poor prognostic factors for the entire group of patients. Patients treated with surgery alone had a better disease-free survival than those who received combination therapy (P less than 0.001). However, patients receiving adjuvant radiation therapy had a higher incidence of lymphatic metastases, tumor involvement of the surgical margin, and large cervical lesions. Adjuvant pelvic radiation therapy did not improve the survival of patients with unilateral nodal metastases or those who had a large cervical lesion with free surgical margins and the absence of nodal involvement. Radiation therapy appears to reduce the incidence of pelvic recurrences. Unfortunately, 84% of patients who developed recurrent tumor after combination therapy had a component of distant failure. The incidence of severe gastrointestinal or genitourinary tract complications was not different in the two treatment groups. However, the incidence of lymphedema was increased in patients who received adjuvant radiation therapy. Although adjuvant radiation therapy appears to be tolerated without a significant increase in serious complications, the extent to which it may improve local control rates and survival in high-risk patients appears to be limited. In view of the high incidence of distant metastases in high-risk patients, consideration should be given to adjuvant systemic chemotherapy in addition to radiation therapy.

  5. External Beam Therapy (EBT)

    Science.gov (United States)

    ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: ... Colorectal Cancer Treatment Head and Neck Cancer Treatment Intensity-Modulated Radiation Therapy (IMRT) Brain ...

  6. Quasi-plane-hypothesis of strain coordination for RC beams seismically strengthened with externally-bonded or near-surface mounted fiber reinforced plastic

    Science.gov (United States)

    Ren, Zhenhua; Zeng, Xiantao; Liu, Hanlong; Zhou, Fengjun

    2013-03-01

    The application of fiber reinforced plastic (FRP), including carbon FRP and glass FRP, for structural repair and strengthening has grown due to their numerous advantages over conventional materials such as externally bonded reinforcement (EBR) and near-surface mounted (NSM) strengthening techniques. This paper summarizes the results from 21 reinforced concrete beams strengthened with different methods, including externally-bonded and near-surface mounted FRP, to study the strain coordination of the FRP and steel rebar of the RC beam. Since there is relative slipping between the RC beam and the FRP, the strain of the FRP and steel rebar of the RC beam satisfy the quasi-plane-hypothesis; that is, the strain of the longitudinal fiber that parallels the neutral axis of the plated beam within the scope of the effective height ( h 0) of the cross section is in direct proportion to the distance from the fiber to the neutral axis. The strain of the FRP and steel rebar satisfies the equation: ɛ FRP= βɛ steel, and the value of β is equal to 1.1-1.3 according to the test results.

  7. SU-F-T-232: Monthly Quality Assurance in External Beam Radiation Therapy Using a Single System

    Energy Technology Data Exchange (ETDEWEB)

    Ding, K [Department of Radiation Oncology, Johns Hopkins University, Baltimore, MD (United States); Ji, T [Department of Radiation Oncology, Johns Hopkins University, Baltimore, MD (United States); Department of Radiation Oncology, The First Hospital, China Medical University, Shenyang, Liaoning (China); Iordachita, I [Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD (United States); Velarde, E; Hyatt, J; Wong, J

    2016-06-15

    Purpose: Monthly quality assurance (QA) is time consuming for external beam radiation therapy, taking as long as 6–8 hours for each machine. It is due to the use and setup of multiple devices for different QA procedures. We have developed a single system with rotational capability for the measurement of both optical light and radiation which significantly reduces the time spent on Monthly QA. Methods: A single system using mirrors, a phosphor screen and a CCD camera is housed on a cylindrical motor so that it can rotate 360 degrees. For monthly QA, the system is placed on the patient couch of the medical accelerator with the plane of the phosphor screen at isocenter for all measurements. For optical QA such as optical distance indicator, room laser and light field, the optical image is collected directly with the camera. For radiation QA such as beam profile, MLC speed, picket-fence test, collimator rotation, table rotation and gantry rotation, a brass build-up plate is attached to the top of the phosphor screen. Two brass plates with islands of different thickness were designed for photon energy and electron energy constancy checks. Flex map, distortion map and uniformity map were developed to calibrate the motor bearing, camera/lens distortion, and the phosphor screen’s measured response across the field. Results: Following the TG142 guidelines for monthly QA with our system, the overall run time is reduced from 6–8 hours to 1.5 hours. Our system’s rotating design allows for quick testing of the gantry radiation isocenter test that is also independent of the sag of the gantry and the EPID. Conclusion: Our system significantly shortens the time needed for monthly QA by unifying the tests with a single system. Future work will be focused on extending the technology to Brachytherapy, IMRT and proton therapy QAs. This work is funded in part by a sponsor research grant from JPLC who owns the Raven technology. John Wong is a co-founder of JPLC.

  8. SU-F-T-232: Monthly Quality Assurance in External Beam Radiation Therapy Using a Single System

    International Nuclear Information System (INIS)

    Ding, K; Ji, T; Iordachita, I; Velarde, E; Hyatt, J; Wong, J

    2016-01-01

    Purpose: Monthly quality assurance (QA) is time consuming for external beam radiation therapy, taking as long as 6–8 hours for each machine. It is due to the use and setup of multiple devices for different QA procedures. We have developed a single system with rotational capability for the measurement of both optical light and radiation which significantly reduces the time spent on Monthly QA. Methods: A single system using mirrors, a phosphor screen and a CCD camera is housed on a cylindrical motor so that it can rotate 360 degrees. For monthly QA, the system is placed on the patient couch of the medical accelerator with the plane of the phosphor screen at isocenter for all measurements. For optical QA such as optical distance indicator, room laser and light field, the optical image is collected directly with the camera. For radiation QA such as beam profile, MLC speed, picket-fence test, collimator rotation, table rotation and gantry rotation, a brass build-up plate is attached to the top of the phosphor screen. Two brass plates with islands of different thickness were designed for photon energy and electron energy constancy checks. Flex map, distortion map and uniformity map were developed to calibrate the motor bearing, camera/lens distortion, and the phosphor screen’s measured response across the field. Results: Following the TG142 guidelines for monthly QA with our system, the overall run time is reduced from 6–8 hours to 1.5 hours. Our system’s rotating design allows for quick testing of the gantry radiation isocenter test that is also independent of the sag of the gantry and the EPID. Conclusion: Our system significantly shortens the time needed for monthly QA by unifying the tests with a single system. Future work will be focused on extending the technology to Brachytherapy, IMRT and proton therapy QAs. This work is funded in part by a sponsor research grant from JPLC who owns the Raven technology. John Wong is a co-founder of JPLC.

  9. Three-Dimensional Non-Coplanar Conformal Radiotherapy Yields Better Results Than Traditional Beam Arrangements for Adjuvant Treatment of Gastric Cancer

    International Nuclear Information System (INIS)

    Soyfer, Viacheslav; Corn, Benjamin W.; Melamud, Alex B.S.; Alani, Shlomi; Tempelhof, Haim; Agai, Reuben; Shmueli, Anat; Figer, Arie; Kovner, Felix

    2007-01-01

    Purpose: The current standard of adjuvant treatment for gastric cancer after curative resection is concurrent administration of radiotherapy and 5-fluorouracil-based chemotherapy. The radiation fields are often arranged as anterioposterior-posteroanterior opposed parallel fields with general recommendations for sparing at least two-thirds of one kidney. We investigated whether a better radiation distribution would be achievable with three-dimensional conformal approaches compared with the classic anterioposterior-posteroanterior fields. Methods and Materials: A total of 19 patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a non-coplanar four-field arrangement. In each case, parallel planning using an anterioposterior-posteroanterior arrangement and a four-field 'box' was performed, and the generated plans were subsequently compared for coverage of target volumes and doses to irradiated organs next to the tumor bed. A separate analysis was performed for kidneys exposed to greater and lower doses in each patient. The mean radiation dose and percentage of kidney volume receiving a dose >20 Gy were registered. Statistical analysis was performed using the two-tailed t test. Results: The clinical target volume was adequately covered in all three plans. In the greater-dose kidney group, all the differences were statistically significant with a benefit for the three-dimensional plan. In the lower-dose kidney group, the differences in the mean radiation dose did not reach the level of statistical significance, and the differences in the kidney volume receiving a dose >20 Gy showed a statistically significant benefit for the three-dimensional plan. Conclusion: Non-coplanar three-dimensional-based conformal planning for postoperative radiotherapy for gastric cancer provided the best results regarding kidney and spinal cord exposure with adequate clinical target volume coverage. This technique was readily implemented in clinical

  10. Three-dimensional non-coplanar conformal radiotherapy yields better results than traditional beam arrangements for adjuvant treatment of gastric cancer.

    Science.gov (United States)

    Soyfer, Viacheslav; Corn, Benjamin W; Melamud, Alex; Alani, Shlomi; Tempelhof, Haim; Agai, Reuben; Shmueli, Anat; Figer, Arie; Kovner, Felix

    2007-10-01

    The current standard of adjuvant treatment for gastric cancer after curative resection is concurrent administration of radiotherapy and 5-fluorouracil-based chemotherapy. The radiation fields are often arranged as anterioposterior-posteroanterior opposed parallel fields with general recommendations for sparing at least two-thirds of one kidney. We investigated whether a better radiation distribution would be achievable with three-dimensional conformal approaches compared with the classic anterioposterior-posteroanterior fields. A total of 19 patients with adenocarcinoma of the stomach were treated with adjuvant chemoradiotherapy using a non-coplanar four-field arrangement. In each case, parallel planning using an anterioposterior-posteroanterior arrangement and a four-field "box" was performed, and the generated plans were subsequently compared for coverage of target volumes and doses to irradiated organs next to the tumor bed. A separate analysis was performed for kidneys exposed to greater and lower doses in each patient. The mean radiation dose and percentage of kidney volume receiving a dose >20 Gy were registered. Statistical analysis was performed using the two-tailed t test. The clinical target volume was adequately covered in all three plans. In the greater-dose kidney group, all the differences were statistically significant with a benefit for the three-dimensional plan. In the lower-dose kidney group, the differences in the mean radiation dose did not reach the level of statistical significance, and the differences in the kidney volume receiving a dose >20 Gy showed a statistically significant benefit for the three-dimensional plan. Non-coplanar three-dimensional-based conformal planning for postoperative radiotherapy for gastric cancer provided the best results regarding kidney and spinal cord exposure with adequate clinical target volume coverage. This technique was readily implemented in clinical practice.

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

    International Nuclear Information System (INIS)

    Macknelly, Andrew; Day, Jane

    2009-01-01

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

  12. Conventional external beam radiation therapy and high dose rate afterloading brachytherapy as a boost for patients older than 70 years

    International Nuclear Information System (INIS)

    Pellizzon, Antonio Cassio Assis; Salvajoli, Joao Vitor; Fogaroli, Ricardo Cesar; Novaes, Paulo Eduardo R.S.; Maia, Maria Aparecida Conte; Ferrigno, Robson

    2005-01-01

    The treatment options for patients with non metastatic prostate cancer range from observation, radical prostatectomy, radiation therapy, hormonal therapy to various combination of some to all of them. Objective: we evaluated the impact on biochemical control of disease (bNED), acute and late intestinal (GI) and urological (GU) morbidity for a group of patients older than 70 years presenting initial or locally advanced prostate cancer treated with fractionated high dose rate brachytherapy (HDRB) as a boost to conventional external beam radiation therapy (RT) at the Department of Radiation Oncology from Hospital do Cancer A. C. Camargo, Sao Paulo, Brazil. Methods: a total of 56 patients older than 70 were treated from March, 1997 to June, 2002. All patients had prior to HDRB a course of RT to a median dose of 45 Gy. HDRB doses ranged from 16 Gy to 20 Gy, given in 4 fractions. Results: the median age of the patients was 74.4 years (range 70-83) and the median follow-up 33 months (range 24 to 60). The 5-year actuarial bNED rate was 77%. Acute GU and GI morbidity G1-2 were seen in 17.8% and 7.1% of patients, respectively. Late G1 or G2 GU morbidity was seen in 10.7% of the patients, while late G3 morbidity was observed in 7.1% of the patients, represented by urethral strictures. Conclusion: this group of patients had similar bNED rates when compared to literature, with acceptable morbidity rates. (author)

  13. Survey of Stereotactic Body Radiation Therapy in Japan by the Japan 3-D Conformal External Beam Radiotherapy Group

    International Nuclear Information System (INIS)

    Nagata, Yasushi; Hiraoka, Masahiro; Mizowaki, Takashi; Narita, Yuichiro; Matsuo, Yukinori; Norihisa, Yoshiki; Onishi, Hiroshi; Shirato, Hiroki

    2009-01-01

    Purpose: To recognize the current status of stereotactic body radiotherapy (SBRT) in Japan, using a nationwide survey conducted by the Japan 3-D Conformal External Beam Radiotherapy Group. Methods and Materials: The questionnaire was sent by mail to 117 institutions. Ninety-four institutions (80%) responded by the end of November 2005. Fifty-three institutions indicated that they have already started SBRT, and 38 institutions had been reimbursed by insurance. Results: A total of 1111 patients with histologically confirmed lung cancer were treated. Among these patients, 637 had T1N0M0 and 272 had T2N0M0 lung cancer. Metastatic lung cancer was found in 702 and histologically unconfirmed lung tumor in 291 patients. Primary liver cancer was found in 207 and metastatic liver cancer in 76 patients. The most frequent schedule used for primary lung cancer was 48Gy in 4 fractions at 22 institutions (52%), followed by 50Gy in 5 fractions at 11 institutions (26%) and 60Gy in 8 fractions at 4 institutions (10%). The tendency was the same for metastatic lung cancer. The average number of personnel involved in SBRT was 1.8 radiation oncologists, including 1.1 certified radiation oncologists, 2.8 technologists, 0.7 nurses, and 0.6 certified quality assurance personnel and 0.3 physicists. The most frequent amount of time for treatment planning was 61-120min, for quality assurance was 50-60min, and for treatment was 30min. There were 14 (0.6% of all cases) reported Grade 5 complications: 11 cases of radiation pneumonitis, 2 cases of hemoptysis, and 1 case of radiation esophagitis. Conclusion: The current status of SBRT in Japan was surveyed.

  14. Clinical significance of increased gelatinolytic activity in the rectal mucosa during external beam radiation therapy of prostate cancer

    International Nuclear Information System (INIS)

    Hovdenak, Nils; Wang Junru; Sung, C.-C.; Kelly, Thomas; Fajardo, Luis F.; Hauer-Jensen, Martin

    2002-01-01

    Purpose: Rectal toxicity (proctitis) is a dose-limiting factor in pelvic radiation therapy. Mucosal atrophy, i.e., net extracellular matrix degradation, is a prominent feature of radiation proctitis, but the underlying mechanisms are not known. We prospectively examined changes in matrix metalloproteinase (MMP)-2 and MMP-9 (gelatinase A and B) in the rectal mucosa during radiation therapy of prostate cancer, as well as the relationships of these changes with symptomatic, structural, and cellular evidence of radiation proctitis. Methods and Materials: Seventeen patients scheduled for external beam radiation therapy for prostate cancer were prospectively enrolled. Symptoms of gastrointestinal toxicity were recorded, and endoscopy with biopsy of the rectal mucosa was performed before radiation therapy, as well as 2 and 6 weeks into the treatment course. Radiation proctitis was assessed by endoscopic scoring, quantitative histology, and quantitative immunohistochemistry. MMP-2 and MMP-9 were localized immunohistochemically, and activities were determined by gelatin zymography. Results: Symptoms, endoscopic scores, histologic injury, and mucosal macrophages and neutrophils increased from baseline to 2 weeks. Symptoms increased further from 2 weeks to 6 weeks, whereas endoscopic and cellular evidence of proctitis did not. Compared to pretreatment values, there was increased total gelatinolytic activity of MMP-2 and MMP-9 at 2 weeks (p=0.02 and p=0.004, respectively) and 6 weeks (p=0.006 and p=0.001, respectively). Active MMP-2 was increased at both time points (p=0.0001 and p=0.002). Increased MMP-9 and MMP-2 at 6 weeks was associated with radiation-induced diarrhea (p=0.007 and p=0.02, respectively) and with mucosal neutrophil infiltration (rho=0.62). Conclusions: Pelvic radiation therapy causes increased MMP-2 and MMP-9 activity in the rectal mucosa. These changes correlate with radiation-induced diarrhea and granulocyte infiltration and may contribute to abnormal

  15. Technique of Injection of Hyaluronic Acid as a Prostatic Spacer and Fiducials Before Hypofractionated External Beam Radiotherapy for Prostate Cancer.

    Science.gov (United States)

    Boissier, Romain; Udrescu, Corina; Rebillard, Xavier; Terrier, Jean-Etienne; Faix, Antoine; Chapet, Olivier; Azria, David; Devonec, Marian; Paparel, Philippe; Ruffion, Alain

    2017-01-01

    To describe a technique combining the implantation of fiducials and a prostatic spacer (hyaluronic acid [HA]) to decrease the rectal toxicity after an image-guided external beam radiotherapy (EBRT) with hypofractionation for prostate cancer and to assess the tolerance and the learning curve of the procedure. Thirty patients with prostate cancer at low or intermediate risk were included in a phase II trial: image-guided EBRT of 62 Gy in 20 fractions of 3.1 Gy with intensity-modulated radiotherapy. A transrectal implantation of 3 fiducials and transperineal injection of 10 cc of HA (NASHA gel spacer, Q-Med AB, Uppsala, Sweden) between the rectum and the prostate was performed by 1 operator. The thickness of HA was measured at 10 points on magnetic resonance imaging to establish a quality score of the injection (maximum score = 10) and determine the learning curve of the procedure. The quality score increased from patients 1-10, 11-20, to 21-30 with respective median scores: 7 [2-10], 5 [4-7], and 8 [3-10]. The average thicknesses of HA between the base, middle part, and apex of the prostate and the rectum were the following: 15.1 mm [6.4-29], 9.8 mm [5-21.2], and 9.9 mm [3.2-21.5]. The injection of the HA induced a median pain score of 4 [1-8] and no residual pain at mid-long term. Creating an interface between the rectum and the prostate and the implantation of fiducials were feasible under local anesthesia with a short learning curve and could become a standard procedure before a hypofractionated EBRT for prostate cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. 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.

  17. Prognostic Utility of Cell Cycle Progression Score in Men With Prostate Cancer After Primary External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Freedland, Stephen J., E-mail: steve.freedland@duke.edu [Department of Surgery, Durham VA Medical Center, Durham, North Carolina (United States); Department of Surgery (Urology), Duke University School of Medicine, Durham, North Carolina (United States); Department of Pathology, Duke University School of Medicine, Durham, North Carolina (United States); Gerber, Leah [Department of Surgery, Durham VA Medical Center, Durham, North Carolina (United States); Department of Surgery (Urology), Duke University School of Medicine, Durham, North Carolina (United States); Department of Pathology, Duke University School of Medicine, Durham, North Carolina (United States); Reid, Julia; Welbourn, William; Tikishvili, Eliso; Park, Jimmy; Younus, Adib; Gutin, Alexander; Sangale, Zaina; Lanchbury, Jerry S. [Myriad Genetics, Inc, Salt Lake City, Utah (United States); Salama, Joseph K. [Department of Radiation Oncology, Durham VA Medical Center, Durham, North Carolina (United States); Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Stone, Steven [Myriad Genetics, Inc, Salt Lake City, Utah (United States)

    2013-08-01

    Purpose: To evaluate the prognostic utility of the cell cycle progression (CCP) score, a RNA signature based on the average expression level of 31 CCP genes, for predicting biochemical recurrence (BCR) in men with prostate cancer treated with external beam radiation therapy (EBRT) as their primary curative therapy. Methods and Materials: The CCP score was derived retrospectively from diagnostic biopsy specimens of men diagnosed with prostate cancer from 1991 to 2006 (n=141). All patients were treated with definitive EBRT; approximately half of the cohort was African American. Outcome was time from EBRT to BCR using the Phoenix definition. Median follow-up for patients without BCR was 4.8 years. Association with outcome was evaluated by Cox proportional hazards survival analysis and likelihood ratio tests. Results: Of 141 patients, 19 (13%) had BCR. The median CCP score for patient samples was 0.12. In univariable analysis, CCP score significantly predicted BCR (P=.0017). The hazard ratio for BCR was 2.55 for 1-unit increase in CCP score (equivalent to a doubling of gene expression). In a multivariable analysis that included Gleason score, prostate-specific antigen, percent positive cores, and androgen deprivation therapy, the hazard ratio for CCP changed only marginally and remained significant (P=.034), indicating that CCP provides prognostic information that is not provided by standard clinical parameters. With 10-year censoring, the CCP score was associated with prostate cancer-specific mortality (P=.013). There was no evidence for interaction between CCP and any clinical variable, including ethnicity. Conclusions: Among men treated with EBRT, the CCP score significantly predicted outcome and provided greater prognostic information than was available with clinical parameters. If validated in a larger cohort, CCP score could identify high-risk men undergoing EBRT who may need more aggressive therapy.

  18. Radiolabeled anti-EGFR-antibody improves local tumor control after external beam radiotherapy and offers theragnostic potential

    International Nuclear Information System (INIS)

    Koi, Lydia; Bergmann, Ralf; Brüchner, Kerstin; Pietzsch, Jens; Pietzsch, Hans-Jürgen; Krause, Mechthild

    2014-01-01

    Purpose: The effect of radioimmunotherapy (RIT) using the therapeutic radionuclide Y-90 bound to the anti-EGFR antibody cetuximab combined with external beam irradiation (EBRT) (EBRIT) on permanent local tumor control in vivo was examined. Methods: Growth delay was evaluated in three human squamous cell carcinoma models after RIT with [ 90 Y]Y-(CHX-A′′-DTPA) 4 -cetuximab (Y-90-cetuximab). The EBRT dose required to cure 50% of the tumors (TCD 50 ) for EBRT alone or EBRIT was evaluated in one RIT-responder (FaDu) and one RIT-non-responder (UT-SCC-5). EGFR expression and microenvironmental parameters were evaluated in untreated tumors, bioavailability was visualized by PET using ([ 86 Y]Y-(CHX-A′′-DTPA) 4 -cetuximab (Y-86-cetuximab) and biodistribution using Y-90-cetuximab. Results: In UT-SCC-8 and FaDu but not in UT-SCC-5 radiolabeled cetuximab led to significant tumor growth delay. TCD 50 after EBRT was significantly decreased by EGFR-targeted RIT in FaDu but not in UT-SCC-5. In contrast to EGFR expression, parameters of the tumor micromilieu and in particular the Y-90-cetuximab biodistribution or Y-86-cetuximab visualization in PET correlated with the responsiveness to RIT or EBRIT. Conclusion: EGFR-targeted EBRIT can improve permanent local tumor control compared to EBRT alone. PET imaging of bioavailability of labeled cetuximab appears to be a suitable predictor for response to EBRIT. This theragnostic approach should be further explored for clinical translation

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

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Kazuhiko, E-mail: kogawa@med.u-ryukyu.ac.jp [Department of Radiology, University of the Ryukyus, Okinawa (Japan); Nakamura, Katsumasa [Department of Clinical Radiology, Kyushu University Hospital at Beppu, Oita (Japan); Sasaki, Tomonari [Department of Radiation Oncology, National Kyushu Center, Fukuoka (Japan); Onishi, Hiroshi [Department of Radiology, Yamanashi University, Yamanashi (Japan); Koizumi, Masahiko [Department of Radiation Oncology, Osaka University, Osaka (Japan); Araya, Masayuki [Department of Radiology, Yamanashi University, Yamanashi (Japan); Mukumoto, Nobutaka; Teshima, Teruki [Department of Medical Physics and Engineering, Osaka University, Osaka (Japan); Mitsumori, Michihide [Department of Radiation Oncology and Image-Applied Therapy, Kyoto University, Kyoto (Japan)

    2011-12-01

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

  20. Migration of intraprostatic fiducial markers and its influence on the matching quality in external beam radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Delouya, Guila; Carrier, Jean-Francois; Beliveau-Nadeau, Dominic; Donath, David; Taussky, Daniel

    2010-01-01

    Purpose: To assess the influence of fiducial marker (FM) migration on the matching quality in external beam radiation therapy (EBRT) for prostate cancer. Materials and methods: The position of FMs were identified using on-board kV imaging (OBI) and their 3-D position established using an in-house reconstruction algorithm for 31 patients with prostate adenocarcinoma. To carry out the match, the positions were overlaid on the digitally reconstructed radiographs (DRR) generated from the planning CT. The distance between each FM was calculated for seven treatments throughout the EBRT course. Four radiotherapy technologists were asked to independently perform and rate the match from OBI to DRR which was then correlated to the extent of FM migration. Results: All the matches were rated by at least three radiotherapy technologists as 'very easy' ('easy' subgroup) for 24 patients (77%), while the other seven patients had their match rated less than 'very easy' and considered the 'not easy' subgroup. The average daily FM migration was 0.93 ± 0.34 mm for the 'easy' subgroup vs. 1.82 ± 0.75 mm for the latter. An average migration >2 mm was seen in five/seven patients in the 'not easy' subgroup as compared to none in the 'easy' subgroup. There was a trend towards less FM migration and better matching if the planning CT was done later than the day of the FM implant (p = 0.093). Conclusions: FM migration >2 mm predicts for a more difficult matching process; PTV margins might have to be adjusted or the planning CT repeated.

  1. Pretreatment PSA predicts for biochemical disease free survival in patients treated with post-prostatectomy external beam irradiation

    International Nuclear Information System (INIS)

    Crane, C.H.; Kelly, M.; Rich, T.A.

    1996-01-01

    Objective: To assess the outcome and determine prognostic factors for patients treated with external beam radiotherapy following radical prostatectomy. Methods and Materials: Forty-four patients were treated after prostatectomy with radiotherapy between March 1988 and October 1993. All patients were free from clinically or radiographically suspicious local or distant disease. One patient underwent neoadjuvant hormonal therapy, but no other patients received hormonal therapy prior to radiation. Pre-radiotherapy PSA and follow-up PSA data were available in all patients. Four patients had undetectable PSA ( 7, and 11% had nodal involvement. Survival was analyzed using the life table method. Actuarial freedom from biochemical (BCM) failure, defined as a rise of greater than 10% or an undetectable PSA becoming detectable, was the primary endpoint studied. Results: Fifty-nine percent of patients had a detectable PSA return to undetectable levels after XRT. The actuarial five year freedom from biochemical failure for all patients was 24%. A significant difference in BCM disease free survival was seen for patients irradiated with a pre-XRT PSA ≤2.7 versus a pre-XRT PSA >2.7 (p=0.0001). Sixty percent of the former group were BCM disease free versus 0% in the latter. Biochemical disease free survival was not affected by preoperative PSA level, presence of undetectable PSA after surgery, surgery to radiation interval, seminal vesicle invasion, clinical stage, pathologic stage, Gleasons grade, or total dose. There were no symptomatic or clinically suspicious local failures, and there were no grade 3, 4, or 5 acute or late complications. There were 69% grade 1 and 2 acute reactions and one grade 2 late complication. Conclusions: Pelvic radiotherapy for patients with a PSA of ≤2.7 after prostatectomy was effective in biochemically controlling 60% of the patients with four years median follow up. To our knowledge these data represent the longest follow-up for this patient

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  3. Breast conserving surgery in combination with intraoperative radiotherapy after previous external beam therapy: an option to avoid mastectomy.

    Science.gov (United States)

    Thangarajah, F; Heilmann, J; Malter, W; Kunze, S; Marnitz, S; Mallmann, P; Wenz, F; Sperk, E

    2018-04-01

    Mastectomy is the standard procedure in patients with in-breast tumor recurrence (IBTR) or breast cancer after irradiation of the chest due to Hodgkin's disease. In certain cases a second breast conserving surgery (BCS) in combination with intraoperative radiotherapy (IORT) is possible. To date, data concerning BCS in combination with IORT in pre-irradiated patients are limited. This is the first pooled analysis of this special indication with a mature follow-up of 5 years. Patients with IBTR after external beam radiotherapy (EBRT; treated in two centers) for breast cancer were included. Patients with previous EBRT including the breast tissue due to other diseases were also included. IORT was performed with the Intrabeam™-device using low kV X-rays. Clinical data including outcome for all patients and toxicity for a representative cohort (LENT-SOMA scales) were obtained. Statistical analyses were done including Kaplan-Meier estimates for local recurrence, distant metastasis and overall survival. A total of 41 patients were identified (39 patients with IBTR, 2 with Hodgkin`s disease in previous medical history). Median follow-up was 58 months (range 4-170). No grade 3/4 acute toxicity occurred within 9 weeks. Local recurrence-free survival rate was 89.9% and overall survival was 82.7% at 5 years. Seven patients developed metastasis within the whole follow-up. BCS in combination with IORT in IBTR in pre-irradiated patients is a feasible method to avoid mastectomy with a low risk of side effects and an excellent local control and good overall survival.

  4. Prognostic Utility of Cell Cycle Progression Score in Men With Prostate Cancer After Primary External Beam Radiation Therapy

    International Nuclear Information System (INIS)

    Freedland, Stephen J.; Gerber, Leah; Reid, Julia; Welbourn, William; Tikishvili, Eliso; Park, Jimmy; Younus, Adib; Gutin, Alexander; Sangale, Zaina; Lanchbury, Jerry S.; Salama, Joseph K.; Stone, Steven

    2013-01-01

    Purpose: To evaluate the prognostic utility of the cell cycle progression (CCP) score, a RNA signature based on the average expression level of 31 CCP genes, for predicting biochemical recurrence (BCR) in men with prostate cancer treated with external beam radiation therapy (EBRT) as their primary curative therapy. Methods and Materials: The CCP score was derived retrospectively from diagnostic biopsy specimens of men diagnosed with prostate cancer from 1991 to 2006 (n=141). All patients were treated with definitive EBRT; approximately half of the cohort was African American. Outcome was time from EBRT to BCR using the Phoenix definition. Median follow-up for patients without BCR was 4.8 years. Association with outcome was evaluated by Cox proportional hazards survival analysis and likelihood ratio tests. Results: Of 141 patients, 19 (13%) had BCR. The median CCP score for patient samples was 0.12. In univariable analysis, CCP score significantly predicted BCR (P=.0017). The hazard ratio for BCR was 2.55 for 1-unit increase in CCP score (equivalent to a doubling of gene expression). In a multivariable analysis that included Gleason score, prostate-specific antigen, percent positive cores, and androgen deprivation therapy, the hazard ratio for CCP changed only marginally and remained significant (P=.034), indicating that CCP provides prognostic information that is not provided by standard clinical parameters. With 10-year censoring, the CCP score was associated with prostate cancer-specific mortality (P=.013). There was no evidence for interaction between CCP and any clinical variable, including ethnicity. Conclusions: Among men treated with EBRT, the CCP score significantly predicted outcome and provided greater prognostic information than was available with clinical parameters. If validated in a larger cohort, CCP score could identify high-risk men undergoing EBRT who may need more aggressive therapy

  5. Thyroid volume measurement in external beam radiotherapy patients using CT imaging: correlation with clinical and anthropometric characteristics

    International Nuclear Information System (INIS)

    Veres, C; Garsi, J P; Rubino, C; De Vathaire, F; Diallo, I; Pouzoulet, F; Bidault, F; Chavaudra, J; Bridier, A; Ricard, M; Ferreira, I; Lefkopoulos, D

    2010-