WorldWideScience

Sample records for hyperfractionated accelerated radiation

  1. Accelerated hyperfractionated radiotherapy for malignant gliomas

    International Nuclear Information System (INIS)

    Buatti, John M.; Marcus, Robert B.; Mendenhall, William M.; Friedman, William A.; Bova, Francis J.

    1996-01-01

    Purpose: To evaluate accelerated hyperfractionated radiotherapy for the treatment of malignant gliomas. Methods and Materials: Between April 1985 and June 1994, 70 adult patients with pathologically confirmed malignant glioma (75% glioblastoma multiforme, 25% anaplastic astrocytoma) suitable for high-dose therapy were selected for treatment with accelerated hyperfractionated radiotherapy, 1.5 Gy twice daily to a total target dose of 60 Gy. Two patients were excluded from analysis (one patient had a fatal pulmonary embolism after 18 Gy; one patient discontinued therapy after 28.5 Gy against medical advice and without sequelae or progression). The 68 patients in the study group had a median age of 52 years and a median Karnofsky performance status of 90. Stereotactic implant ( 125 I) or stereotactic radiosurgery boosts were delivered to 16 patients (24%) in the study group. Minimum follow-up was 6 months. Results: Median survival was 13.8 months and median progression-free survival was 7.4 months. The absolute Kaplan-Meier survival rate was 16% at 2 years and 4% at 5 years. Multivariate analysis for the prognostic impact of age, gender, histology, Karnofsky performance status, symptomatology, surgical resection vs. biopsy, and boost vs nonboost therapy revealed that Karnofsky performance status ≥ 90, boost therapy, and surgical excision predicted significantly improved outcome. No severe toxicity occurred in patients treated with accelerated hyperfractionated radiotherapy alone, although 5% required steroids temporarily for edema. Progression occurred during treatment in one patient (1.5%). Conclusion: This regimen of accelerated hyperfractionated radiotherapy is well tolerated and leads to results comparable with those of standard therapy. The rate of disease progression during treatment is significantly better (p = 0.001) than is reported for patients treated with standard fractionation, with or without chemotherapy. This regimen is a reasonable starting point

  2. Assessment of long-term quality of life of esophageal carcinoma patients treated with continuous accelerated hyperfractionated and late-course accelerated hyperfractionated radiotherapy

    International Nuclear Information System (INIS)

    Wang Yang; He Shaoqin; Shi Xuehui; Jiang Kaida; Yao Weiqiang; Wang Ying

    2002-01-01

    Objective: To compare the long-term quality of life in esophageal carcinoma patients treated with continuous accelerated hyperfractionated (CAHF) and late-course accelerated hyperfractionated (LCAF) radiotherapy. Methods: Subjective and Objective Management Analysis (SOMA) scale, Symptom Checklist 90 (SCL-90) and Life Satisfaction Index A (LSIA) questionnaire were mailed to the long survivors in both CAHF and LCAF groups to assess the long-term quality of life including symptoms, psychological status and life satisfaction. Results: There was no significant difference between the two groups in the score of quality of life such as late radiation reaction, SCL-90 and LSI-A. Conclusions: 1. It is reasonable to assess the quality of life with these scales for esophageal carcinoma patients treated with radiotherapy, 2. Preliminary results demonstrate that there is no significant difference in long-term quality of life between the CAHF and LCAF radiotherapy groups, 3. Methods of evaluating the long-term quality of life for esophageal carcinoma patients treated with radiotherapy needs further investigation, preferably involving more patients and setting on control arm

  3. Preoperative concurrent CBDCA chemotherapy and accelerated hyperfractionated radiotherapy for squamous cell carcinoma of the maxillary region

    International Nuclear Information System (INIS)

    Omura, Ken; Harada, Hiroyuki; Suzuki, Haruhiko; Takeuchi, Yosuke; Hatano, Kazuo; Togawa, Takashi

    2001-01-01

    Between 1994 and 2000, 28 patients with T3/T4 squamus cell carcinoma of the maxillary region (maxillary sinus, 22; maxillary gingiva, 4; maxillary bone, 1; buccal mucosa, 1) had accelerated hyperfractionated radiotherapy combined with simultaneous CBDCA chemotherapy preoperatively, at Chiba Cancer Center Hospital. The protocol consisted of combined therapy with accelerated hyperfractionated irradiation of 1.6 Gy, twice a day, to a total dose of 32.0-51.2 Gy and concurrent intra-arterial or intravenous infusion of CBDCA 20-30 mg/body/day for a cumulative total dose of 270-480 mg. After completion of the preoperative combined therapy, the clinical CR rate was 17.9%, and the good PR·CR rate was 32.1%. According to the initial findings and response to the combined therapy, all patients had maxillectomy (subtotal, 3; total, 16; extended, 9) 4 weeks after completion of the preoperative combined therapy. Postoperatively, the complete pathologic response (Ohboshi and Shimozato's classification, grade III and IV) rate was 28.6%. And the actuarial local control rate was 85.7%, with a mean follow-up of 46.2 months. Based on these results, we believe this preoperative therapy with CBDCA chemotherapy and accelerated hyperfractionated radiation is a significant choice as treatment for squamous cell cancer of the maxillary region. (author)

  4. Preventing radiation retinopathy with hyperfractionation

    International Nuclear Information System (INIS)

    Monroe, Alan T.; Bhandare, Niranjan; Morris, Christopher G.; Mendenhall, William M.

    2005-01-01

    Purpose: The purpose of this study was to determine factors associated with the development of radiation retinopathy in a large series of patients with head-and-neck cancer. In particular, we addressed whether the use of hyperfractionated radiation therapy was effective in reducing the risk of retinopathy. Methods and materials: One hundred eighty-six patients received a significant dose to the retina as part of curative radiotherapy. Primary sites included: nasopharynx, 46; paranasal sinus, 64; nasal cavity, 69; and palate, 7. Prescription doses varied depending on primary site and histology. Hyperfractionated (twice-daily) radiation was delivered to 42% of the patients in this study, typically at 1.10 to 1.20 Gy per fraction. The remainder were treated once-daily. Retinal doses were determined from computerized dosimetry plans when available. For all other patients, retinal doses were retrospectively calculated using reconstructed off-axis dosimetry taken from contours through the center of the globes. Retinal dose was defined as the minimum dose received by at least 25% of the globe. The median retinal dose was 56.85 Gy. Patients were followed for a median of 7.6 years. Results: Thirty-one eyes in 30 patients developed radiation retinopathy, resulting in monocular blindness in 25, bilateral blindness in 1, and decreased visual acuity in 4. The median time to the diagnosis of retinopathy was 2.6 years (range, 11 months to 5.3 years). The actuarial incidence of developing radiation retinopathy was 20% at both 5 and 10 years. The incidence of developing ipsilateral blindness due to retinopathy was 16% at 5 years and 17% at 10 years. Site-specific incidences varied considerably, with ethmoid sinus (9 of 25, 36%), nasal cavity (13 of 69, 19%), and maxillary sinus (6 of 35, 17%) being the most common sites associated with radiation retinopathy. Three of 72 patients (4%) receiving retinal doses less than 50 Gy developed retinopathy. Higher retinal doses resulted in a

  5. Preoperative concurrent CBDCA chemotherapy and accelerated hyperfractionated radiotherapy for squamous cell carcinoma of the maxillary region

    Energy Technology Data Exchange (ETDEWEB)

    Omura, Ken; Harada, Hiroyuki [Tokyo Medical and Dental Univ. (Japan). Graduate School; Suzuki, Haruhiko; Takeuchi, Yosuke; Hatano, Kazuo; Togawa, Takashi

    2001-11-01

    Between 1994 and 2000, 28 patients with T3/T4 squamus cell carcinoma of the maxillary region (maxillary sinus, 22; maxillary gingiva, 4; maxillary bone, 1; buccal mucosa, 1) had accelerated hyperfractionated radiotherapy combined with simultaneous CBDCA chemotherapy preoperatively, at Chiba Cancer Center Hospital. The protocol consisted of combined therapy with accelerated hyperfractionated irradiation of 1.6 Gy, twice a day, to a total dose of 32.0-51.2 Gy and concurrent intra-arterial or intravenous infusion of CBDCA 20-30 mg/body/day for a cumulative total dose of 270-480 mg. After completion of the preoperative combined therapy, the clinical CR rate was 17.9%, and the good PR{center_dot}CR rate was 32.1%. According to the initial findings and response to the combined therapy, all patients had maxillectomy (subtotal, 3; total, 16; extended, 9) 4 weeks after completion of the preoperative combined therapy. Postoperatively, the complete pathologic response (Ohboshi and Shimozato's classification, grade III and IV) rate was 28.6%. And the actuarial local control rate was 85.7%, with a mean follow-up of 46.2 months. Based on these results, we believe this preoperative therapy with CBDCA chemotherapy and accelerated hyperfractionated radiation is a significant choice as treatment for squamous cell cancer of the maxillary region. (author)

  6. A meta-analysis of hyperfractionated and accelerated radiotherapy and combined chemotherapy and radiotherapy regimens in unresected locally advanced squamous cell carcinoma of the head and neck

    Directory of Open Access Journals (Sweden)

    Budach V

    2006-01-01

    Full Text Available Abstract Background Former meta-analyses have shown a survival benefit for the addition of chemotherapy (CHX to radiotherapy (RT and to some extent also for the use of hyperfractionated radiation therapy (HFRT and accelerated radiation therapy (AFRT in locally advanced squamous cell carcinoma (SCC of the head and neck. However, the publication of new studies and the fact that many older studies that were included in these former meta-analyses used obsolete radiation doses, CHX schedules or study designs prompted us to carry out a new analysis using strict inclusion criteria. Methods Randomised trials testing curatively intended RT (≥60 Gy in >4 weeks/>50 Gy in Results Thirty-two trials with a total of 10 225 patients were included into the meta-analysis. An overall survival benefit of 12.0 months was observed for the addition of simultaneous CHX to either CFRT or HFRT/AFRT (p Conclusion RT combined with simultaneous 5-FU, cisplatin, carboplatin, and mitomycin C as single drug or combinations of 5-FU with one of the other drugs results in a large survival advantage irrespective the employed radiation schedule. If radiation therapy is used as single modality, hyperfractionation leads to a significant improvement of overall survival. Accelerated radiation therapy alone, especially when given as split course radiation schedule or extremely accelerated treatments with decreased total dose, does not increase overall survival.

  7. Late course accelerated hyperfractionated radiotherapy of nasopharyngeal carcinoma (LCAF)

    International Nuclear Information System (INIS)

    He Xiayun; Liu Taifu; He Shaoqin; Huan Sulan; Pan Ziqiang

    2007-01-01

    Background and purpose: To study the efficacy of late course accelerated fractionated (LCAF) radiotherapy in the treatment of nasopharyngeal carcinoma (NPC). The end-points were local control, radiation-induced complications, and factors influencing survival. Patients and methods: Between December 1995 and April 1998, 178 consecutive NPC patients were admitted for radiation treatment. The radiation beam used was 60 Co γ or 6 MV X rays. For the first two-thirds of the treatment, two daily fractions of 1.2 Gy were given to the primary lesion, with an interval of ≥6 h, 5 days per week to a total dose of 48 Gy/40 fractions, over a period of 4 weeks. For the last third of the treatment, i.e., beginning the 5th week of treatment, an accelerated hyperfractionated schedule was carried out. The dose per fraction was increased to 1.5 Gy, 2 fractions per day with an interval of ≥6 h, the total dose for this part of the protocol was 30 Gy/20 fractions over 2 weeks. Thus the total dose was 78 Gy in 60 fractions in 6 weeks. Results: All patients completed the treatment. Acute mucositis: none in 2 cases, Grade 1 in 43 cases, Grade 2 in 78 cases, Grade 3 in 52 cases, and Grade 4 in 3 cases. Local control rate: the 5 year nasopharyngeal local control rate was 87.7%, and the cervical lymph nodes local control rate was 85.7%. The 5-year distant metastasis rate was 26.1%, and 5 year survivals were 67.9%, 16 (9%) patients had radiation-induced cranial nerve palsy, 7(4%) patients had temporal lobe or brainstem damage. Conclusions: With this treatment schedule, patients' tolerance was good, local control and 5 year survivals were better than conventional fractionation schedules, and radiation-related late complications did not increase, as 5-year survival rates of conventional fractionation radiotherapy were only 58%. Randomized clinical trials are being carried out to further confirm the efficacy of LCAF for nasopharyngeal carcinoma

  8. A phase ii study of concurrent accelerated hyperfractionated radiotherapy and carboplatin/oral etoposide for elderly patients with stage iii non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Jeremic, Branislav; Shibamoto, Yuta; Milicic, Biljana; Milisavljevic, Slobodan; Nikolic, Nebojsa; Dagovic, Aleksandar; Aleksandrovic, Jasna; Radosavljevic-Asic, Gordana

    1999-01-01

    Purpose: To investigate feasibility, toxicity, and efficacy of accelerated hyperfractionated radiation therapy and concurrent carboplatin/oral etoposide in elderly (> 70 years) patients with stage III non-small-cell lung cancer. Methods and Materials: Between January 1988 and June 1993, a total of 58 patients entered a phase II study. Carboplatin (400 mg/m 2 ) was given intravenously on days 1 and 29, and etoposide (50 mg/m 2 ) was given orally on days 1-21 and 29-42. Accelerated hyperfractionated radiotherapy was administered starting on day 1, with a total dose of 51 Gy in 34 fractions over 3.5 weeks. Results: In 55 evaluable patients, the complete response rate was 27% and the overall response rate was 65%. For the 55 patients, the median survival time was 10 months, and the 1-, 2-, and 5-year survival rates were 45%, 24%, and 9.1%, respectively. The median time until relapse was 8 months and the 1-, 2-, and 5-year relapse-free survival rates were 45%, 20%, and 9.1%, respectively. The median time to local recurrence was 14 months and the 5-year local control rate was 13%; the median time to distant metastasis was 18 months and the 5-year distant metastasis-free rate was 15%. Hematological, esophageal, and bronchopulmonary acute grade 3 or 4 toxicities were observed in 22%, 7%, and 4% of the patients, respectively. There was no grade 5 toxicity or late grade ≥ 3 toxicity. Conclusion: Concurrent accelerated hyperfractionated radiotherapy and carboplatin/oral etoposide produced relatively low and acceptable toxicity. The survival results appeared to be comparable to those obtained in nonelderly patients with stage III non-small-cell lung cancer treated by full-dose radiation

  9. A randomized phase III study of accelerated hyperfractionation versus standard in patients with unresected brain metastases: a report of the radiation therapy oncology group (RTOG) 9104

    International Nuclear Information System (INIS)

    Murray, Kevin J.; Scott, Charles; Greenberg, Harvey M.; Emami, Bahman; Seider, Michael; Vora, Nayana L.; Olson, Craig; Whitton, Anthony; Movsas, Benjamin; Curran, Walter

    1997-01-01

    Purpose: To compare 1-year survival and acute toxicity rates between an accelerated hyperfractionated (AH) radiotherapy (1.6 Gy b.i.d.) to a total dose of 54.4 Gy vs. an accelerated fractionation (AF) of 30 Gy in 10 daily fractions in patients with unresected brain metastasis. Methods and Materials: The Radiation Therapy Oncology Group (RTOG) accrued 445 patients to a Phase III comparison of accelerated hyperfractionation vs. standard fractionation from 1991 through 1995. All patients had histologic proof of malignancy at the primary site. Brain metastasis were measurable by CT or MRI scan and all patients had a Karnofsky performance score (KPS) of at least 70 and a neurologic function classification of 1 or 2. For AH, 32 Gy in 20 fractions over 10 treatment days (1.6 Gy twice daily) was delivered to the whole brain. A boost of 22.4 Gy in 14 fractions was delivered to each lesion with a 2-cm margin. Results: The average age in both groups was 60 years; nearly two-thirds of all patients had lung primaries. Of the 429 eligible and analyzable patients, the median survival time was 4.5 months in both arms. The 1-year survival rate was 19% in the AF arm vs. 16% in the AH arm. No difference in median or 1-year survival was observed among patients with solitary metastasis between treatment arms. Recursive partitioning analysis (RPA) classes have previously been identified and patients with a KPS of 70 or more, a controlled primary tumor, less than 65 years of age, and brain metastases only (RPA class I), had a 1-year survival of 35% in the AF arm vs. 25% in the AH arm (p = 0.95). In a multivariate model, only age, KPS, extent of metastatic disease (intracranial metastases only vs. intra- and extracranial metastases), and status of primary (controlled vs. uncontrolled) were statistically significant (at p < 0.05). Treatment assignment was not statistically significant. Overall Grade III or IV toxicity was equivalent in both arms, and one fatal toxicity at 44 days secondary

  10. COMPARISON OF CONVENTIONAL RADIATIOTHERAPY AND ACCELERATED HYPERFRACTIONATED RADIATIOTHERAPY IN CHEMORADIATION TREATMENT FOR SMALL CELL LUNG CANCER

    Directory of Open Access Journals (Sweden)

    I. A. Gulidov

    2013-01-01

    Full Text Available The 5-year treatment outcomes of 69 patients with stage IIA–IIIA locally advanced small cell lung cancer have been presented. Accelerated hyperfractionated radiotherapy was administered in the uneven daily dose fractionation (single dose of 1 + 1,5 Gy with a 5–6hour interval to a total dose of 60–70 Gy depending on the health status and lung function. The complete response was achieved in 13 (42 % patients, the median survival was 28 months and the 5-year survival rate was 26,2 %. Grade III lung and pericardium toxicities (according to RTOG toxicity scale were observed in 3,2 % and 6,5 % of patients, respectively. No grade III–IV radiation-induced blood and esophageal damages were found.

  11. Split Course Hyperfractionated Accelerated Radio-Chemotherapy (SCHARC) for patients with advanced head and neck cancer: Influence of protocol deviations and hemoglobin on overall survival, a retrospective analysis

    OpenAIRE

    Stadler, Peter; Putnik, Kurt; Kreimeyer, Thore; Sprague, Lisa D; Koelbl, Oliver; Schäfer, Christof

    2006-01-01

    Abstract Background The advantage of hyperfractionated accelerated radiation therapy for advanced head and neck cancer has been reported. Furthermore, randomized trials and meta-analyses have confirmed the survival benefit of additional chemotherapy to radiotherapy. We retrospectively analyzed the efficiency and toxicity of the Regensburg standard therapy protocol "SCHARC" and the overall survival of our patients. Methods From 1997 to 2004, 64 patients suffering from advanced head and neck ca...

  12. Hyperfractionation radiation therapy in advanced head and neck cancer

    International Nuclear Information System (INIS)

    Kim, Jin Hee; Ye, Ji Won

    2003-01-01

    The effects of hyperfractionation radiation therapy, such as the failure pattern and survival, on the treatment results in advanced stage head and neck cancer were studied. Between September 1990 and October 1998, 24 patients with advanced stage (III, IV) head and neck cancers, were treated using hyperfractionation radiation therapy in the Department at Radiation Oncology at the Keimyung University Dongsan Medical Center. The male to female ratio was 7 ; 1, and the age range from 38 to 71 years with the median of 56 years. With regard to the TNM stage, 11 patients were stage III and 13 were stage IV. The sites of primary cancer were the nasopharynx in six, the hypopharynx in 6, the larynx in five, the oropharynx in three, the maxillary sinus in three, and the oral cavity in one patient. The radiotherapy was delivered by 6 MV X-ray, with a fraction size of 1.2 Gy at two fractions a day, with at least 6 hours inter-fractional interval. The mean total radiation doses was 72 Gy, (ranging from 64.4 to 76.8 Gy). Fallow-up periods ranged between 3 and 136 months, with the median of 52 months. The overall survival rates at 3 and 5 years in all patients were 66.7% and 52.4%. The disease-free survival rates at 3 and 5 years (3YDFS, 5YDFS) in all patients Were 66.7% and 47.6%. The 3YDFS and 5YDFS in stage III patients were 81.8% and 63.6%, and those in stage IV patients were 53.8% and 32.3%. Ten patients were alive with no local nor distant failures at the time of analyses. Six patients (25%) died due to distant metastasis and 12.5% died due to local failure. Distant metastasis was the major cause of failure, but 2 patients died due to unknown failures and 3 of other diseases. The distant metastasis sites were the lung (3 patients), the bone (1 patient), and the liver (2 patients). One patient died of second esophageal cancer. There were no severe late complications, with the exception of 1 osteoradionecrosis of the mandible 58 months after treatment. Although this study was

  13. Pilot study of human recombinant interferon gamma and accelerated hyperfractionated thoracic radiation therapy in patients with unresectable stage IIIA/B nonsmall cell lung cancer

    International Nuclear Information System (INIS)

    Shaw, Edward G.; Deming, Richard L.; Creagan, Edward T.; Nair, Suresh; Su, John Q.; Levitt, Ralph; Steen, Preston D.; Wiesenfeld, Martin; Mailliard, James A.

    1995-01-01

    Purpose: Gamma interferon has a wide range of properties, including the ability to sensitize solid tumor cells to the effects of ionizing radiation. The North Central Cancer Treatment Group has previously completed pilot studies of accelerated hyperfractionated thoracic radiation therapy (AHTRT) in patients with unresectable Stage IIIA/B nonsmall cell lung cancer (NSCLC). This Phase I study was designed to assess the toxicity of concomitant gamma interferon and AHTRT in a similar patient population. Methods and Materials: Between December 1991 and May 1992, 18 patients with unresectable Stage IIIA/B NSCLC were treated with daily gamma interferon (0.2 mg subcutaneously) concomitant with AHTRT (60 Gy given in 1.5 Gy twice daily fractions). All patients had an Eastern Cooperative Oncology Group performance status of 0 or 1 with weight loss < 5%. Eight patients had Stage IIIA and 10 had Stage IIIB disease. Results: Nine patients (50%) experienced severe, life-threatening, or fatal toxicities. Eight of the patients (44%) developed significant radiation pneumonitis, which was severe in six patients and fatal in two patients (11% treatment-related mortality). Two patients (11%) developed severe radiation esophagitis. With follow-up of 15-21 months, 2 patients are alive, and 16 have died. The median survival time and 1-year survival rate is 7.8 months and 38%, respectively. Conclusion: Gamma interferon appeared to sensitize normal lung tissue to the effects of radiation, as demonstrated by the high incidence of severe or fatal radiation pneumonitis. We do not recommend pursuing gamma interferon as a radiosensitizer in this setting

  14. Safety and adverse events of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) for rectal cancer

    International Nuclear Information System (INIS)

    Doi, Hiroshi; Kamikonya, Norihiko; Hirota, Shozo; Beppu, Naohito; Yanagi, Hidenori

    2014-01-01

    We presented good tolerability and short-term outcomes of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART; 25 Gy in 10 fractions for 5 days) combined with chemotherapy in a total of 73 patients with lower rectal cancer. Age, gender, tumor differentiation, and the type of surgery seemed to have no apparent effects on toxicity of SC-HART. SC-HART appeared to have a good feasibility for use in further clinical trials. (author)

  15. Neurocognitive outcome in brain metastases patients treated with accelerated-fractionation vs. accelerated-hyperfractionated radiotherapy: an analysis from Radiation Therapy Oncology Group Study 91-04

    International Nuclear Information System (INIS)

    Regine, W.F.; Scott, C.; Murray, K.; Curran, W.

    2001-01-01

    Purpose: To evaluate neurocognitive outcome as measured by the Mini-Mental Status Examination (MMSE) among patients with unresectable brain metastases randomly assigned to accelerated fractionation (AF) vs. accelerated hyperfractionated (AH) whole-brain radiation therapy (WBRT). Methods and Materials: The Radiation Therapy Oncology Group (RTOG) accrued 445 patients with unresectable brain metastases to a Phase III comparison of AH (1.6 Gy b.i.d. to 54.4 Gy) vs. AF (3 Gy q.d. to 30 Gy). All had a KPS of ≥ 70 and a neurologic function status of 0-2. Three hundred fifty-nine patients had MMSEs performed and were eligible for this analysis. Changes in the MMSE were analyzed according to criteria previously defined in the literature. Results: The median survival was 4.5 months for both arms. The average change in MMSE at 2 and 3 months was a drop of 1.4 and 1.1, respectively, in the AF arm as compared to a drop of 0.7 and 1.3, respectively, in the AH arm (p=NS). Overall, 91 patients at 2 months and 23 patients at 3 months had both follow-up MMSE and computed tomography/magnetic resonance imaging documentation of the status of their brain metastases. When an analysis was performed taking into account control of brain metastases, a significant effect on MMSE was observed with time and associated proportional increase in uncontrolled brain metastases. At 2 months, the average change in MMSE score was a drop of 0.6 for those whose brain metastases were radiologically controlled as compared to a drop of 1.9 for those with uncontrolled brain metastases (p=0.47). At 3 months, the average change in MMSE score was a drop of 0.5 for those whose brain metastases were radiologically controlled as compared to a drop of 6.3 for those with uncontrolled brain metastases (p=0.02). Conclusion: Use of AH as compared to AF-WBRT was not associated with a significant difference in neurocognitive function as measured by MMSE in this patient population with unresectable brain metastases and

  16. A phase II study of hyperfractionated accelerated radiotherapy (HART) after induction cisplatin (CDDP) and vinorelbine (VNR) for stage III Non-small-cell lung cancer (NSCLC)

    International Nuclear Information System (INIS)

    Ishikura, Satoshi; Ohe, Yuichiro; Nihei, Keiji; Kubota, Kaoru; Kakinuma, Ryutaro; Ohmatsu, Hironobu; Goto, Koichi; Niho, Seiji; Nishiwaki, Yutaka; Ogino, Takashi

    2005-01-01

    Purpose: The purpose was to assess the feasibility and efficacy of hyperfractionated accelerated radiotherapy (HART) after induction chemotherapy for Stage III non-small-cell lung cancer. Methods and materials: Treatment consisted of 2 cycles of cisplatin 80 mg/m 2 on Day 1 and vinorelbine 25 mg/m 2 on Days 1 and 8 every 3 weeks followed by HART, 3 times a day (1.5, 1.8, 1.5 Gy, 4-h interval) for a total dose of 57.6 Gy. Results: Thirty patients were eligible. Their median age was 64 years (range, 46-73 years), 24 were male, 6 were female, 8 had performance status (PS) 0, 22 had PS 1, 9 had Stage IIIA, and 21 had Stage IIIB. All but 1 patient completed the treatment. Common grade ≥3 toxicities during the treatment included neutropenia, 25; infection, 5; esophagitis, 5; and radiation pneumonitis, 3. The overall response rate was 83%. The median survival was 24 months (95% confidence interval [CI], 13-34 months), and the 2-year overall survival was 50% (95% CI, 32-68%). The median progression-free survival was 10 months (95% CI, 8-20 months). Conclusion: Hyperfractionated accelerated radiotherapy after induction of cisplatin and vinorelbine was feasible and promising. Future investigation employing dose-intensified radiotherapy in combination with chemotherapy is needed

  17. A meta-analysis of hyperfractionated and accelerated radiotherapy and combined chemotherapy and radiotherapy regimens in unresected locally advanced squamous cell carcinoma of the head and neck

    International Nuclear Information System (INIS)

    Budach, W; Hehr, T; Budach, V; Belka, C; Dietz, K

    2006-01-01

    Former meta-analyses have shown a survival benefit for the addition of chemotherapy (CHX) to radiotherapy (RT) and to some extent also for the use of hyperfractionated radiation therapy (HFRT) and accelerated radiation therapy (AFRT) in locally advanced squamous cell carcinoma (SCC) of the head and neck. However, the publication of new studies and the fact that many older studies that were included in these former meta-analyses used obsolete radiation doses, CHX schedules or study designs prompted us to carry out a new analysis using strict inclusion criteria. Randomised trials testing curatively intended RT (≥60 Gy in >4 weeks/>50 Gy in <4 weeks) on SCC of the oral cavity, oropharynx, hypopharynx, and larynx published as full paper or in abstract form between 1975 and 2003 were eligible. Trials comparing RT alone with concurrent or alternating chemoradiation (5-fluorouracil (5-FU), cisplatin, carboplatin, mitomycin C) were analyzed according to the employed radiation schedule and the used CHX regimen. Studies comparing conventionally fractionated radiotherapy (CFRT) with either HFRT or AFRT without CHX were separately examined. End point of the meta-analysis was overall survival. Thirty-two trials with a total of 10 225 patients were included into the meta-analysis. An overall survival benefit of 12.0 months was observed for the addition of simultaneous CHX to either CFRT or HFRT/AFRT (p < 0.001). Separate analyses by cytostatic drug indicate a prolongation of survival of 24.0 months, 16.8 months, 6.7 months, and 4.0 months, respectively, for the simultaneous administration of 5-FU, cisplatin-based, carboplatin-based, and mitomycin C-based CHX to RT (each p < 0.01). Whereas no significant gain in overall survival was observed for AFRT in comparison to CFRT, a substantial prolongation of median survival (14.2 months, p < 0.001) was seen for HFRT compared to CFRT (both without CHX). RT combined with simultaneous 5-FU, cisplatin, carboplatin, and mitomycin C as

  18. ACCELERATED HYPERFRACTIONATED RADIOTHERAPY IN THE TREATMENT FOR INOPERABLE, LOCALLY ADVANCED GASTRIC CANSER

    Directory of Open Access Journals (Sweden)

    S. S. Litinskiy

    2015-01-01

    Full Text Available Purpose: to compare survival of patients with locally advanced inoperable gastric cancer (LAIGC, receiving accelerated hyperfractionated (AHF or conventionally fractionated (CF radiation therapy (RT. Methods and Materials. Between November 1993 and March 2010, 137 patients with LAIGC receiving CF (2 Gy daily or AHF (1.3 Gy b.i.d. to total at least 50 Gy RT in combination or without chemotherapy were retrospectively selected from the hospital database of Arkhangelsk clinical oncological dispensary. Overall survival (OS assessed using actuarial analysis, Kaplan – Meier method and Cox regression. results. The CF and AHF groups were 102 and 35 patients, respectively. Median follow-up time for all patients was 12 years. By the time of analysis 123 (90 % patients of all cohort died. Median, 7-year survival were 24 (95 % confidence intervals (CI, 17–31 vs 16 (95 % CI, 11–21 months, hazard ratio (HR=0.71 (95 % CI, 0.46–1.06, р=0.097; and 19 % (95 % CI 8–34 % vs 6% (95 % CI 2–13 % in the AHF and CF groups, respectively. In multivariate OS model the difference decreased to HR=0.87 (95 % CI, 0.49–1.55. The location of the tumor in median third (HR=0.60, 95 % CI, 0.37–0.99 in refer to upper third was the only independent factor influencing survival.  There was no influence of the total dose in chosen level on survival. conclusion. Our retrospective shows trend towards better OS for those LAIGC patients receiving RT in AHF regimen compared to CF. The prospective randomized study with conformal radiation technics is necessary to confirm these findings.

  19. Quality of Survival and Growth in Children and Young Adults in the PNET4 European Controlled Trial of Hyperfractionated Versus Conventional Radiation Therapy for Standard-Risk Medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Colin, E-mail: crk1@soton.ac.uk [University of Southampton Faculty of Medicine and University Hospital Southampton National Health Service Foundation Trust, Southampton (United Kingdom); Bull, Kim [University of Southampton Faculty of Medicine and University Hospital Southampton National Health Service Foundation Trust, Southampton (United Kingdom); Chevignard, Mathilde [Hôpitaux de Saint Maurice, Saint Maurice (France); Neurophysiology, University of Pierre et Marie-Curie Paris 6, Paris (France); Culliford, David [University of Southampton Faculty of Medicine and University Hospital Southampton National Health Service Foundation Trust, Southampton (United Kingdom); Dörr, Helmuth G. [Kinder- und Jugendklinik der Universität Erlangen, Erlangen (Germany); Doz, François [Institut Curie and University Paris Descartes, Sorbonne Paris Cité (France); Kortmann, Rolf-Dieter [Department of Radiation Therapy, University of Leipzig, Leipzig (Germany); Lannering, Birgitta [Department of Pediatrics, The Sahlgren Academy, University of Gothenburg, Gothenburg (Sweden); Massimino, Maura [Fondazione Istituto di Ricovero e Cura a Carattere Scientifico IRCCS Istituto Nazionale dei Tumori, Milan (Italy); Navajas Gutiérrez, Aurora [Hospital Universitario Cruces, Baracaldo-Vizcaya (Spain); Rutkowski, Stefan [University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Spoudeas, Helen A. [Center for Pediatric Endocrinology, University College London, London (United Kingdom); Calaminus, Gabriele [Pediatric Oncology, University of Muenster, Muenster (Germany)

    2014-02-01

    Purpose: To compare quality of survival in “standard-risk” medulloblastoma after hyperfractionated radiation therapy of the central nervous system with that after standard radiation therapy, combined with a chemotherapy regimen common to both treatment arms, in the PNET4 randomised controlled trial. Methods and Materials: Participants in the PNET4 trial and their parents/caregivers in 7 participating anonymized countries completed standardized questionnaires in their own language on executive function, health status, behavior, health-related quality of life, and medical, educational, employment, and social information. Pre- and postoperative neurologic status and serial heights and weights were also recorded. Results: Data were provided by 151 of 244 eligible survivors (62%) at a median age at assessment of 15.2 years and median interval from diagnosis of 5.8 years. Compared with standard radiation therapy, hyperfractionated radiation therapy was associated with lower (ie, better) z-scores for executive function in all participants (mean intergroup difference 0.48 SDs, 95% confidence interval 0.16-0.81, P=.004), but health status, behavioral difficulties, and health-related quality of life z-scores were similar in the 2 treatment arms. Data on hearing impairment were equivocal. Hyperfractionated radiation therapy was also associated with greater decrement in height z-scores (mean intergroup difference 0.43 SDs, 95% confidence interval 0.10-0.76, P=.011). Conclusions: Hyperfractionated radiation therapy was associated with better executive function and worse growth but without accompanying change in health status, behavior, or quality of life.

  20. Quality of Survival and Growth in Children and Young Adults in the PNET4 European Controlled Trial of Hyperfractionated Versus Conventional Radiation Therapy for Standard-Risk Medulloblastoma

    International Nuclear Information System (INIS)

    Kennedy, Colin; Bull, Kim; Chevignard, Mathilde; Culliford, David; Dörr, Helmuth G.; Doz, François; Kortmann, Rolf-Dieter; Lannering, Birgitta; Massimino, Maura; Navajas Gutiérrez, Aurora; Rutkowski, Stefan; Spoudeas, Helen A.; Calaminus, Gabriele

    2014-01-01

    Purpose: To compare quality of survival in “standard-risk” medulloblastoma after hyperfractionated radiation therapy of the central nervous system with that after standard radiation therapy, combined with a chemotherapy regimen common to both treatment arms, in the PNET4 randomised controlled trial. Methods and Materials: Participants in the PNET4 trial and their parents/caregivers in 7 participating anonymized countries completed standardized questionnaires in their own language on executive function, health status, behavior, health-related quality of life, and medical, educational, employment, and social information. Pre- and postoperative neurologic status and serial heights and weights were also recorded. Results: Data were provided by 151 of 244 eligible survivors (62%) at a median age at assessment of 15.2 years and median interval from diagnosis of 5.8 years. Compared with standard radiation therapy, hyperfractionated radiation therapy was associated with lower (ie, better) z-scores for executive function in all participants (mean intergroup difference 0.48 SDs, 95% confidence interval 0.16-0.81, P=.004), but health status, behavioral difficulties, and health-related quality of life z-scores were similar in the 2 treatment arms. Data on hearing impairment were equivocal. Hyperfractionated radiation therapy was also associated with greater decrement in height z-scores (mean intergroup difference 0.43 SDs, 95% confidence interval 0.10-0.76, P=.011). Conclusions: Hyperfractionated radiation therapy was associated with better executive function and worse growth but without accompanying change in health status, behavior, or quality of life

  1. Quality of survival and growth in children and young adults in the PNET4 European controlled trial of hyperfractionated versus conventional radiation therapy for standard-risk medulloblastoma.

    Science.gov (United States)

    Kennedy, Colin; Bull, Kim; Chevignard, Mathilde; Culliford, David; Dörr, Helmuth G; Doz, François; Kortmann, Rolf-Dieter; Lannering, Birgitta; Massimino, Maura; Navajas Gutiérrez, Aurora; Rutkowski, Stefan; Spoudeas, Helen A; Calaminus, Gabriele

    2014-02-01

    To compare quality of survival in "standard-risk" medulloblastoma after hyperfractionated radiation therapy of the central nervous system with that after standard radiation therapy, combined with a chemotherapy regimen common to both treatment arms, in the PNET4 randomised controlled trial. Participants in the PNET4 trial and their parents/caregivers in 7 participating anonymized countries completed standardized questionnaires in their own language on executive function, health status, behavior, health-related quality of life, and medical, educational, employment, and social information. Pre- and postoperative neurologic status and serial heights and weights were also recorded. Data were provided by 151 of 244 eligible survivors (62%) at a median age at assessment of 15.2 years and median interval from diagnosis of 5.8 years. Compared with standard radiation therapy, hyperfractionated radiation therapy was associated with lower (ie, better) z-scores for executive function in all participants (mean intergroup difference 0.48 SDs, 95% confidence interval 0.16-0.81, P=.004), but health status, behavioral difficulties, and health-related quality of life z-scores were similar in the 2 treatment arms. Data on hearing impairment were equivocal. Hyperfractionated radiation therapy was also associated with greater decrement in height z-scores (mean intergroup difference 0.43 SDs, 95% confidence interval 0.10-0.76, P=.011). Hyperfractionated radiation therapy was associated with better executive function and worse growth but without accompanying change in health status, behavior, or quality of life. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Acute tolerance of hyperfractionated accelerated total body irradiation

    International Nuclear Information System (INIS)

    Latz, D.; Schraube, P.; Wannenmacher, M.

    1996-01-01

    Background: Acute side effects of total body irradiation lead to intense molestations of the patients. Therefore, it is desirable to take measures to reduce these side effects. In a retrospective study the frequency on acute side effects of a hyperfractionated accelerated total body irradiation was assessed and compared to frequencies of other exposure schedules published in the literature. Additionally the influence of ondansetron on the frequency of nausea and vormiting was investigated. Patients and Method: From 1989 to 1992, 76 patients (47 male, 29 female; median age 38 years) underwent total body irradiation before autologeous bone marrow transplantation. They received 3 daily doses of 1.20 Gy each every 4 h on 4 successive days to a total dose of 14,40 Gy. Thirty-nine patients received 3x8 mg (daily, intravenous or per os) ondansetron during the whole course of irradiation. Results: The most relevant side effects were nausea and vomiting. Patients, who did not receive ondansetron (n=37) showed a nausea and emesis rate of 73%. With ondansetron (n=39) nausea and emesis were reduced to 38%. Also the grade of severity of these side effects was reduced. Conclusions: Ondansetron proved to be an effective medicament for relieving nausea and vormiting during total body irradiation. The results obtained are in concordance with those published in the literature. (orig.) [de

  3. Intracellular recovery - basis of hyperfractionation

    International Nuclear Information System (INIS)

    Hagen, U.; Guttenberger, R.; Kummermehr, J.

    1988-01-01

    The radiobiological basis fo a hyperfractionated radiation therapy versus conventional fractionation with respect to therapeutic gain, i.e., improved normal tissue sparing for the same level of tumour cell inactivation, will be presented. Data on the recovery potential of various tissues as well as the kinetics of repair will be given. The problem of incomplete repair with short irradiation intervals will be discussed. (orig.) [de

  4. Treatment of 29 patients with bulky squamous cell carcinoma of the cervix with simultaneous cisplatin, 5-fluorouracil, and split-course hyperfractionated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, D.; Yordan, E.; Reddy, S.; Bonomi, P.; Lee, M.S.; Lincoln, S.; Graham, J.; Dolan, T.; Miller, A.; Phillips, A. (Rush Presbyterian-St. Lukes Hospital, Chicago, IL (USA))

    1990-09-01

    Attempting to improve local disease control in bulky primary or recurrent pelvic tumors, 29 patients with squamous cell carcinoma of the cervix were treated with concomitant chemotherapy and split-course hyperfractionated radiation therapy between April 1983 and August 1988. Cisplatin (CDDP) and 5-fluorouracil (5-FU) have been shown to be radiation enhancers; furthermore, CDDP, radiation therapy, and continuous-infusion 5-FU have elicited high local response rates in head and neck squamous cell carcinoma. A pilot study of cyclical week on/week off CDDP, continuous-infusion 5-FU, and hyperfractionated radiation therapy was developed. Radiation was administered at 116 cGy twice daily, Days 1-5, every other week for a median dose of 4600 cGy to a pelvic field, with paraaortic extension if indicated. Concomitant chemotherapy included CDDP 60 mg/m2 IV Day 1 and 5-FU 600 mg/m2 IV continuous infusion for 96 hr following CDDP infusion. Patients received a median of four cycles of combined treatment, and intracavitary or interstitial brachytherapy followed in 21 patients. Local pelvic response was achieved in 29 of 29 (100%): complete response (CR) in 19 of 29 (66%), partial response (PR) in 10 of 29 (34%). Among CR patients 10 of 19 (53%) were without evidence of disease at a mean follow-up of 29 (range 12-76) months. Five-year actuarial disease-free survival among complete responders was 65%. Of the 10 CR patients 2 failed in the pelvis, for a local control rate of 17/19 (89%). Chemotherapy-related and acute radiation morbidity was minimal but 2 patients required surgical correction of radiation injury. Aggressive combination of split-course hyperfractionated radiation therapy with radiation enhancers resulted in promising local control of bulky pelvic tumor, with an acceptable complication rate, in this otherwise very poor prognostic group of patients.

  5. Hyperfractionated external radiation therapy in stage IIIB carcinoma of uterine cervix: a prospective pilot study

    International Nuclear Information System (INIS)

    Faria, Sergio L.; Ferrigno, Robson

    1997-01-01

    Purpose: Brazil has one of the highest incidence of carcinoma of the cervix in the world. Half of the patients have advanced stages at the diagnosis. Due to this large number of patients we decided to conduct a prospective pilot study to investigate the tolerance to and survival rate with hyperfractionated external radiotherapy only in patients with Stage IIIB carcinoma of the uterine cervix. Methods and Materials: Between January 1991 and December 1993, 23 patients underwent hyperfractionated external beam radiotherapy without brachytherapy. All cases were biopsy proven squamous cell carcinoma of cervix clinically Staged as IIIB (FIGO). Hyperfractionation (HFX) was given with 1.2 Gy doses, twice daily at 6-h interval, 5 days/week, to the whole pelvis up to 72 Gy within 30 working days. Complications were evaluated by an adaptation of the RTOG Radiation Morbidity Scoring Table graded as 1 = none/mild; 2 = moderate, and 3 = severe. Results: Follow-up ranged from 27 to 50 months (median 40 months) on the 9 to 23 living patients at the time of the analysis in December 1995. There was no severe acute toxicity, but moderate acute reaction was high: 74%. The commonest site of complication was the intestine where severe late toxicity occurred in 2 of 23 (9%). Overall survival rate at 27 months was 48% and at 40 months was 43%. Discussion: There is little information in literature about HFX in carcinoma of the cervix. This is the third published study about it and the one that gave the highest total dose with external HFX of 60 x 1.2 Gy = 72 Gy. Theoretically, through the linear quadratic formula this schedule of HFX would be equivalent to 30 x 2 Gy = 60 Gy of standard fractionation, both treatments given in 30 working days. HFX schedules must be tested to establish their safety. Present results suggest being possible to further increase the total dose in the pelvis with hyperfractionated irradiation

  6. Hyperfractionation in carcinoma of the cervix: tumor control and late bowel complications

    International Nuclear Information System (INIS)

    Viswanathan, Faith Rangad; Varghese, Cherian; Peedicayil, Abraham; Lakshmanan, Jeyaseelan; Narayan, Viswanathan Perungulam

    1999-01-01

    Purpose: Hyperfractionation has been advocated to improve local tumor control by increasing radiation dose without increasing late normal tissue complications. The aim of this study was to determine if hyperfractionation decreased late bowel complications. Methods and Materials: Thirty patients with Stage II and III cervical cancer were randomized to receive either hyperfractionation or conventional fractionation. Patients were followed for 5 years and monitored for tumor control, recurrence, and bowel complications. The relative risks of tumor control and bowel complications were computed at 1 year and 5 years of follow-up. Kaplan-Meier survival curves were plotted to determine probabilities of being tumor-free and bowel complication-free. Results: There were 15 patients in each group. At 1 year of follow-up, 2 patients in the hyperfractionation group (13%) and 7 patients in the conventional treatment group (45%) had tumor (relative risk [RR] 0.3; 95% confidence interval [CI] 0.1, 1.1; p = 0.054). Delayed bowel complications were seen in 8 patients in the hyperfractionation group and 1 patient in the conventional treatment group (RR 7.5; 95% CI 1.1, 52; p = 0.014). At 5 years, 2 patients in the hyperfractionation group and 8 patients in the conventional treatment group had tumor (RR 0.3; 95% CI 0.1, 1.1; p = 0.04). Delayed bowel complications (Grades 2 and 3) occurred in 9 women in the hyperfractionation group and 2 patients in the conventional group (RR 5.4; 95% CI 1.5, 19.5; p 0.0006). Kaplan-Meier analysis showed that the hyperfractionation group had significantly more bowel complications over the 5 years of follow-up (p 0.024). Conclusion: Hyperfractionation may result in better tumor control both at 1 year and at 5 years following treatment of cervical cancer. However, hyperfractionation could lead to increased late bowel complications and must be used judiciously in the treatment of cervical cancer

  7. Phase I and pharmacologic study of 72-hour infused 5-fluorouracil and hyperfractionated cyclical radiation

    Energy Technology Data Exchange (ETDEWEB)

    Byfield, J.E.; Frankel, S.S.; Sharp, T.R.; Hornbeck, C.L.; Callipari, F.B.

    1985-04-01

    The authors have studied 21 patients infused for 72 hours with 5- Fluorouracil (5-FU) at progressive doses combined with hyperfractionated radiation. The schedule was chosen as being one capable of inducing 5-FU radiosensitization (RS). All patients were started at a daily 5-FU dose of 40 mg/kg/24 hours; doses were then escalated with each subsequent treatment cycle to limiting toxicity or until taken off study. Patients received between one and six infusion cycles. Every treatment cycle included coincident hyperfractionated radiation to various body areas including the abdomen, chest, and head and neck region. Radiation fractionation was invariant; 1,000 rad were delivered in four equal fractions. Two fractions of 250 rad each were given on days 1 and 2 of each three day 5-FU cycle, i.e. at approximately 0, 8, 24, and 32 hours into the drug infusion. Patients were followed for toxicity; serum 5-FU concentrations were determined using a high pressure liquid chromatographic assay. 5-FU clearances were calculated from the mean serum drug levels and the infused drug dose. The toxicity spectrum was not found to be significantly different from infused drug alone in this dose range except when the head and neck region received coincident irradiation. In that region the two anticipated toxicities combined in what appears to be a synergistic fashion to enhance mucositis. Most toxicities including gastrointestinal and bone marrow appeared dependent on the mean serum 5-FU level as did mucositis itself. 5-FU clearance was found to be non-linear in this dose region but did not appear influenced by radiation to any part of the body.

  8. Phase I and pharmacologic study of 72-hour infused 5-fluorouracil and hyperfractionated cyclical radiation

    International Nuclear Information System (INIS)

    Byfield, J.E.; Frankel, S.S.; Sharp, T.R.; Hornbeck, C.L.; Callipari, F.B.

    1985-01-01

    The authors have studied 21 patients infused for 72 hours with 5- Fluorouracil (5-FU) at progressive doses combined with hyperfractionated radiation. The schedule was chosen as being one capable of inducing 5-FU radiosensitization (RS). All patients were started at a daily 5-FU dose of 40 mg/kg/24 hours; doses were then escalated with each subsequent treatment cycle to limiting toxicity or until taken off study. Patients received between one and six infusion cycles. Every treatment cycle included coincident hyperfractionated radiation to various body areas including the abdomen, chest, and head and neck region. Radiation fractionation was invariant; 1,000 rad were delivered in four equal fractions. Two fractions of 250 rad each were given on days 1 and 2 of each three day 5-FU cycle, i.e. at approximately 0, 8, 24, and 32 hours into the drug infusion. Patients were followed for toxicity; serum 5-FU concentrations were determined using a high pressure liquid chromatographic assay. 5-FU clearances were calculated from the mean serum drug levels and the infused drug dose. The toxicity spectrum was not found to be significantly different from infused drug alone in this dose range except when the head and neck region received coincident irradiation. In that region the two anticipated toxicities combined in what appears to be a synergistic fashion to enhance mucositis. Most toxicities including gastrointestinal and bone marrow appeared dependent on the mean serum 5-FU level as did mucositis itself. 5-FU clearance was found to be non-linear in this dose region but did not appear influenced by radiation to any part of the body

  9. Preoperative hyperfractionated accelerated radiotherapy and radical surgery in advanced head and neck cancer: A prospective phase II study

    International Nuclear Information System (INIS)

    Lindholm, Paula; Valavaara, Ritva; Aitasalo, Kalle; Kulmala, Jarmo; Laine, Juhani; Elomaa, Liisa; Sillanmaeki, Lauri; Minn, Heikki; Grenman, Reidar

    2006-01-01

    Background and purpose: To evaluate whether preoperative hyperfractionated accelerated radiotherapy (RT) combined with major radical surgery is feasible and successful in the treatment of advanced primary head and neck cancer. Patients and methods: Ninety four patients with histologically confirmed head and neck squamous cell cancer (HNSCC) in the oral cavity (41/96; 43%), supraglottis (14/96; 15%), glottis (5/96; 5%), oropharynx (16/96; 17%), nasal cavity/paranasal sinuses (8/96; 8%), nasopharynx (3/96; 3%), hypopharynx (7/96; 7%) and two (2%) with unknown primary tumour and large cervical lymph nodes entered into the study. 21/96 patients (22%) had stage II, 17/96 (18%) stage III and 58/96 patients (60%) stage IV disease. The patients received preoperative hyperfractionated RT 1.6 Gy twice a day, 5 days a week to a median tumour dose of 63 Gy with a planned break for 11 days (median) after the median dose of 37 Gy. Then, after a median of 27 days the patients underwent major radical surgery of the primary tumour and metastatic lymph nodes including reconstructions with pedicled or microvascular free flaps when indicated as a part of the scheduled therapy. 12/96 patients had only ipsilateral or bilateral neck dissections. Results: After a median follow-up time of 37.2 mos 77/96 (80.2%) patients had complete locoregional control. All but 2 patients had complete histological remission after surgery. 40/96 pts were alive without disease, two of them after salvage surgery. 32/96 patients had relapsed; 15 had locoregional and 13 distant relapses, 4 patients relapsed both locoregionally and distantly. Fifty patients have died; 29 with locoregional and/or distant relapse, eight patients died of second malignancy, and 19 had intercurrent diseases. Disease-specific and overall survival at 3 years was 67.7 and 51%, respectively. Acute grade three mucosal reactions were common, but transient and tolerable. Late grade 3-4 adverse effects were few. Conclusions: Preoperative

  10. High-dose, hyperfractionated, accelerated radiotherapy using a concurrent boost for the treatment of nonsmall cell lung cancer: unusual toxicity and promising early results

    International Nuclear Information System (INIS)

    King, Stephen C.; Acker, Jeffrey C.; Kussin, Peter S.; Marks, Lawrence B.; Weeks, Kenneth J.; Leopold, Kenneth A.

    1996-01-01

    Purpose: The treatment of nonsmall cell lung cancer (NSCLC) with conventional radiotherapy (RT) results in inadequate local tumor control and survival. We report results of a Phase II trial designed to treat patients with a significantly increased total dose administered in a reduced overall treatment time using a hyperfractionated, accelerated treatment schedule with a concurrent boost technique. Methods and Materials: A total of 49 patients with unresectable Stage IIIA/IIIB (38 patients) or medically inoperable Stage I/II (11 patients) NSCLC were prospectively enrolled in this protocol. Radiation therapy was administered twice daily, 5 days/week with > 6 h between each treatment. The primary tumor and adjacent enlarged lymph nodes were treated to a total dose of 73.6 Gy in 46 fractions of 1.6 Gy each. Using a concurrent boost technique, electively irradiated nodal regions were simultaneously treated with a dose of 1.25 Gy/fraction for the first 36 fractions to a total dose of 45 Gy. Results: Median survival for the entire group of 49 patients is 15.3 months. Actuarial survival at 2 years is 46%: 60% for 11 Stage I/II patients, 55% for 21 Stage IIIA patients, and 26% for 17 Stage IIIB patients. The actuarial rate of freedom from local progression at 2 years is 64% for the entire group of 49 patients: 62% for Stage I/II patients, 70% for Stage IIIA patients, and 55% for Stage IIIB patients. Patients who underwent serial bronchoscopic reevaluation (4 Stage I/II, 8 Stage IIIA, and 6 Stage IIIB) have an actuarial rate of local control of 71% at 2 years. The median total treatment time was 32 days. Nine of 49 patients (18%) experienced Grade III acute esophageal toxicity. The 2-year actuarial risk of Grade III or greater late toxicity is 30%. The 2-year actuarial rate of severe-late pulmonary and skin-subcutaneous toxicity is 20% and 15%, respectively. Conclusion: This treatment regimen administers a substantially higher biologically effective dose compared with

  11. Long-term Outcomes in Treatment of Invasive Bladder Cancer With Concomitant Boost and Accelerated Hyperfractionated Radiation Therapy

    International Nuclear Information System (INIS)

    Canyilmaz, Emine; Yavuz, Melek Nur; Serdar, Lasif; Uslu, Gonca Hanedan; Zengin, Ahmet Yasar; Aynaci, Ozlem; Haciislamoglu, Emel; Bahat, Zumrut; Yoney, Adnan

    2014-01-01

    Purpose: The aim of this study was to evaluate the long-term clinical efficacy and toxicity of concomitant boost and accelerated hyperfractionated radiation therapy (CBAHRT) in patients with invasive bladder cancer. Methods and Materials: Between October 1997 and September 2012, 334 patients with diagnoses of invasive bladder cancer were selected. These patients received CBAHRT as a bladder-conserving approach. The treatment consisted of a dose of 45 Gy/1.8 Gy to the whole pelvis with a daily concomitant boost of 1.5 Gy to the tumor. Total dose was 67.5 Gy in 5 weeks. A total of 32 patients (10.3%) had a diagnosis of stage T1, 202 (64.3%) were at stage T2, 46 (14.6%) were at stage T3a, 22 (7%) were at stage T3b, and 12 (3.8%) were at stage T4a. Results: The follow-up period was 33.1 months (range, 4.3-223.3 months). Grade 3 late intestinal toxicity was observed in 9 patients (2.9%), whereas grade 3 late urinary toxicity was observed in 8 patients (2.5%). The median overall survival (OS) was 26.3 months (95% confidence interval [CI]: 21.4-31.2). The 5-, 10, and 15-year OS rates were 32.1% (standard error [SE], ± 0.027), 17.9% (SE, ± 0.025) and 12.5% (SE, ± 0.028), respectively. The median cause-specific survival (CSS) was 42.1 months (95% CI: 28.7-55.5). The 5-, 10-, and 15-year CSS rates were 43.2% (SE, ± 0.03), 30.3% (SE, ± 0.03), and 28% (SE, ± 0.04), respectively. The median relapse-free survival (RFS) was 111.8 months (95% CI: 99.6-124). The 5-, 10-, and 15-year RFS rates were 61.9% (SE, ± 0.03), 57.6% (SE, ± 0.04), and 48.2% (SE, ± 0.07), respectively. Conclusions: The CBAHRT technique demonstrated acceptable toxicity and local control rates in patients with invasive bladder cancer, and this therapy facilitated bladder conservation. In selected patients, the CBAHRT technique is a practical alternative treatment option with acceptable 5-, 10-, and 15-year results in patients undergoing cystectomy as well as concurrent chemoradiation therapy

  12. Long-term Outcomes in Treatment of Invasive Bladder Cancer With Concomitant Boost and Accelerated Hyperfractionated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Canyilmaz, Emine, E-mail: dremocan@yahoo.com [Department of Radiation Oncology, Karadeniz Technical University, Trabzon (Turkey); Yavuz, Melek Nur [Department of Radiation Oncology, Akdeniz University, Antalya (Turkey); Serdar, Lasif [Department of Radiation Oncology, Karadeniz Technical University, Trabzon (Turkey); Uslu, Gonca Hanedan; Zengin, Ahmet Yasar [Department of Radiation Oncology, Kanuni Research and Education Hospital, Trabzon (Turkey); Aynaci, Ozlem; Haciislamoglu, Emel; Bahat, Zumrut; Yoney, Adnan [Department of Radiation Oncology, Karadeniz Technical University, Trabzon (Turkey)

    2014-11-01

    Purpose: The aim of this study was to evaluate the long-term clinical efficacy and toxicity of concomitant boost and accelerated hyperfractionated radiation therapy (CBAHRT) in patients with invasive bladder cancer. Methods and Materials: Between October 1997 and September 2012, 334 patients with diagnoses of invasive bladder cancer were selected. These patients received CBAHRT as a bladder-conserving approach. The treatment consisted of a dose of 45 Gy/1.8 Gy to the whole pelvis with a daily concomitant boost of 1.5 Gy to the tumor. Total dose was 67.5 Gy in 5 weeks. A total of 32 patients (10.3%) had a diagnosis of stage T1, 202 (64.3%) were at stage T2, 46 (14.6%) were at stage T3a, 22 (7%) were at stage T3b, and 12 (3.8%) were at stage T4a. Results: The follow-up period was 33.1 months (range, 4.3-223.3 months). Grade 3 late intestinal toxicity was observed in 9 patients (2.9%), whereas grade 3 late urinary toxicity was observed in 8 patients (2.5%). The median overall survival (OS) was 26.3 months (95% confidence interval [CI]: 21.4-31.2). The 5-, 10, and 15-year OS rates were 32.1% (standard error [SE], ± 0.027), 17.9% (SE, ± 0.025) and 12.5% (SE, ± 0.028), respectively. The median cause-specific survival (CSS) was 42.1 months (95% CI: 28.7-55.5). The 5-, 10-, and 15-year CSS rates were 43.2% (SE, ± 0.03), 30.3% (SE, ± 0.03), and 28% (SE, ± 0.04), respectively. The median relapse-free survival (RFS) was 111.8 months (95% CI: 99.6-124). The 5-, 10-, and 15-year RFS rates were 61.9% (SE, ± 0.03), 57.6% (SE, ± 0.04), and 48.2% (SE, ± 0.07), respectively. Conclusions: The CBAHRT technique demonstrated acceptable toxicity and local control rates in patients with invasive bladder cancer, and this therapy facilitated bladder conservation. In selected patients, the CBAHRT technique is a practical alternative treatment option with acceptable 5-, 10-, and 15-year results in patients undergoing cystectomy as well as concurrent chemoradiation therapy.

  13. Classical spreading-fractionation, hyperfractionation, hypofractionation: let us attempt to be practical

    International Nuclear Information System (INIS)

    Cosset, J.M.; Baillet, F.

    1986-01-01

    The so-called classical spreading-fractionation (5 sessions of 2 Gy per week) was elaborated originally by the first generation of radiotherapists at the beginning of the century. It is a remarkable fact that even today the most up-to-date radiobiologists are in agreement that this regimen usually represents the best possible compromise between antitumoral efficacy and toxicity to healthy tissue. Hyperfractionation is still in the clinical trial stage with the aim of defining its precise place in clinical practice. At the present there is only one formal indication apart from within this framework: tumors with very rapid times for doubling in size, since hyperfractionation alone can deliver a high dose in a short period of time (accelerated treatment). Hypofractionation can be highly recommended for palliative treatment, because of its simplicity and efficacy. In contrast, when large size tumours (particularly digestive) are treated in patients with an elevated expected rate of recovery, this technique may provoke late complications and should, a priori, be avoided. For small size tumours however (ENT, breast) it would appear possible to elaborate hypofractio - nation protocols allowing local control to a similar degree to that obtained with the classical regimen, without significantly increasing late complications, on the condition that radiation parameters (dose, spread, fractionation) be cho - sen with the greatest care [fr

  14. Alterations of total non stimulated salivary flow in patients with squamous cell carcinoma of the mouth and oropharynx submitted to hyperfractionated radiation therapy

    International Nuclear Information System (INIS)

    Guebur, Maria Isabela; Rapoport, Abrao; Sassi, Laurindo Moacir; Oliveira, Benedito Valdecir de; Ramos, Gyl Henrique Albrecht; Pereira, Jose Carlos Gasparin

    2004-01-01

    Prevention and early diagnosis are actually the most effective measures that we dispose to improve the prognostic of the malignant tumors. The mouth and oropharynx tumors are treated with success, when early diagnosed. The radiotherapy is almost always one of the selected treatments for these tumors. When cancer is diagnosed in advanced stages, many a time the treatment needs to be carried out swiftly to be efficient, and consequently the radio therapist use the hyperfractionated therapy, with the patient receiving two lower doses of radiation in two sessions daily, amounting to a higher daily dosage, of about 160 cGy/2x/day. When the major salivary glands are present in the radiated field, the xerostomia appears by the second week of treatment (1500 to 2000 cGy), changing the patient's health, and causing difficulties for him to eat, speak and sleep. The objective of this study was to evaluate the quantitative alterations of the total non stimulated salivate flow of patients who underwent hyperfractionated therapy for the treatment of squamous cell carcinoma of mouth and oropharynx. Samples of twelve male patients saliva from Erasto Gaertner Hospital in Curitiba, PR, Brazil, were examined. Two samples of saliva were collected from each patient, the first one before the beginning of the radiotherapy, and the second at the end of the treatment. As a result, we obtained salivary loss in 91.7% of the patients, with a percentage of total salivary flow loss of 62.9%, registered in the second collection. We concluded that the hyperfractionated therapy causes a marked xerostomia when the major salivary glands are in the radiated field. (author)

  15. A multi-institutional phase II study of hyperfractionated accelerated radiation therapy for unresectable non-small cell lung cancer: initial report of ECOG 4593

    International Nuclear Information System (INIS)

    Tannehill, Scott P.; Froseth, Carrie; Wagner, Henry; Petereit, Dan P.; Mehta, Minesh P.

    1996-01-01

    Purpose: To assess the feasibility, acute toxicity, response and survival in a trial of hyperfractionated accelerated radiation therapy for unresectable locally advanced non-small cell lung cancer (NSCLC) using a t.i.d. regimen 5 days a week in an 8 hour schedule. Materials and Methods: Thirty patients (pts) from 6 institutions were enrolled in this pilot trial. Pt characteristics: 24 male, 6 female; median age 67 yrs (range 47-84); ECOG PS 0 in 22 pts, 1 in 8 pts; weight loss >5% in 7 pts. Stage was II (inoperable) in 1 pt, IIIA in 12 pts, and IIIB in 17 pts. Radiation therapy (total 57.6 Gy/36 fx) encompassing gross disease and draining lymphatics to 36 Gy (1.5 Gy b.i.d., 8 hours apart) with daily off-cord concomitant boost to 21.6 Gy (1.8 Gy 4 hours after first fraction) was given over 12 treatment days (15 elapsed days). Results: (28(30)) (93%) pts completed radiation therapy on schedule without toxicity-related treatment interruptions. Two pts did not complete radiation therapy; 1 due to in-field progression and 1 due to fatal acute gastric bleed unrelated to therapy. Two additional pts died in the first 6 weeks: 1 due to a presumed acute cardiovascular event and another due to complications of pre-existing cardiovascular disease. The major treatment-related toxicities were esophagitis in 6 pts (18%: 5 Grade 3 and 1 Grade 4) scored using a study specific esophagitis grading tool and 2 grade 3 dermatitis, in a total of 6 pts. Only 1 pt (3%) required hospitalization for IV hydration (Grade 4 esophagitis). Median weight loss at 6 weeks was 3 kg. Response data are pending in 2 pts and unavailable in 2 due to early death. Of the remaining 26 pts, local response analysis showed CR in 4, PR in 14, stable in 7 and progressive disease in 1 for an overall response rate of (18(26)) (69%). With a median potential follow-up of 13 months, the median survival has not yet been reached. The 1-yr actuarial survival is 63%. Exclusion of the 3 pts experiencing early death (in

  16. Hyperfractionated-accelerated radiotherapy followed by radical surgery in locally advanced tumors of the oral cavity

    International Nuclear Information System (INIS)

    Hoeller, U.; Biertz, I.; Tribius, S.; Alberti, W.; Flinzberg, S.; Schmelzle, R.

    2006-01-01

    Purpose: to evaluate the outcome of hyperfractionated-accelerated radiotherapy and subsequent planned primary tumor resection and radical neck dissection in locally advanced tumors of the oral cavity. Patients and Methods: this retrospective analysis evaluates 126 subsequent patients who were treated between 1988 and 1997 for locally advanced tumors of the oral cavity (with extension into the oropharynx in 17 patients), 34 (27%) AJCC stage III and 92 (73%) stage IV. Primary tumor and nodal metastases were irradiated with 1.4 Gy bid to a median total dose of 72.8 Gy (range 58.8-75.6 Gy). Then, planned radical surgery of the primary site according to the initial tumor extent and cervical nodes was performed. Median follow-up of living patients was 6 years (range 1-11 years). Results: 4 weeks after radiotherapy, 14 patients (11%) had complete tumor remission, 92 (73%) partial remission, 15 (12%) no change, and five (4%) progressive disease. Complete resection was achieved in 117 (93%) patients (nine incomplete resections). 5-year locoregional control rate was 62 ± 9%, overall survival 36 ± 9%. Surgery-related morbidity occurred in 42 patients (33%; mainly delayed wound healing and fistulae), overall severe treatment-related morbidity in 46 patients (36%). 24/84 relapse-free patients (29%) required a percutaneous gastrostomy or nasal tube ≥ 1 year after therapy. Conclusion: in this study, the outcome of combined curative radiotherapy and planned surgery of the primary tumor and neck nodes was comparable to reported results of hyperfractionated radiotherapy with or without salvage surgery of the neck nodes with respect to locoregional control and overall survival. Planned surgery carries a substantial risk of morbidity and seems to offer no benefit in comparison to salvage surgery of the neck nodes only. Therefore, salvage surgery is preferred. (orig.)

  17. Accelerated Hyperfractionated Radiotherapy for Locally Advanced Uterine Cervix Cancers

    International Nuclear Information System (INIS)

    Seo, Young Seok; Cho, Chul Koo; Yoo, Seong Yul

    2008-01-01

    To assess the efficacy of the use of accelerated hyperfractionated radiotherapy (AHRT) for locally advanced uterine cervix cancers. Between May 2000 and September 2002, 179 patients were identified with FIGO stage IIB, IIIB, and IVA cancers. Of the 179 patients, 45 patients were treated with AHRT (AHRT group) and 134 patients were treated with conventional radiotherapy (CRT group), respectively. Patients undergoing the AHRT regimen received a dose of 30 Gy in 20 fractions (1.5 Gyx2 fractions/day) to the whole pelvis. Subsequently, with a midline block, we administered a parametrial boost with a dose of 20 Gy using 2 Gy fractions. Patients also received two courses of low-dose-rate brachytherapy, up to a total dose of 85∼90 Gy to point A. In the CRT group of patients, the total dose to point A was 85∼90 Gy. The overall treatment duration was a median of 37 and 66 days for patients that received AHRT and CRT, respectively. Statistical analysis was calculated by use of the Kaplan-Meier method, the log-rank test, and Chi-squared test. For patients that received cisplatin-based concurrent chemotherapy and radiotherapy, the local control rate at 5 years was 100% and 79.2% for the AHRT and CRT group of patients, respectively (p=0.028). The 5-year survival rate for patients with a stage IIB bulky tumor was 82.6% and 62.1% for the AHRT group and CRT group, respectively (p=0.040). There was no statistically significant difference for severe late toxicity between the two groups (p=0.561). In this study, we observed that treatment with AHRT with concurrent chemotherapy allows a significant advantage of local control and survival for locally advanced uterine cervix cancers

  18. The role of accelerated hyperfractionated radiotherapy in the treatment of inoperable non-small cell lung cancer: a controlled clinical trial

    International Nuclear Information System (INIS)

    Reinfuss, M.; Kowalska, T.; Glinski, C.

    2000-01-01

    Radiotherapy remains the basic form of treatment in cases of non-small cell lung cancer (NSCLC) but there still exist controversies concerning optimal radiotherapy regimen and in particular, the total dose and fractionation schedules. To prove whether the question: if using an unconventional dose fractionation regimen (accelerated hyperfractionation) could improve the results of palliative teleradiotherapy patients with NSCLC. Between 1997 and 2000 in the Cancer Centre in Cracow (COOK) a controlled clinical trial was conducted in a group of 150 patients with locally advanced (III Deg) inoperable and unsuitable for radical radiotherapy NSCLC, with no major symptoms of the disease. In 76 patients conventionally fractionated radiotherapy was performed - 50 Gy in 25 fractions during 5 weeks (CF). 74 patients were irradiated twice a day (AHF); the dose per fraction was 1.25 Gy and the minimum interval between fractions - 6 hours. The total dose was 50 Gy in 40 fractions during 26 days. The probability of 12 months survival was 47.4% in the CF arm and 45.9% in the AHF arm; the probability of 24 months survival was 16.2% and 15.8%, respectively. In all 76 patients in CF arm the treatment was carried out in prescribed time without breaks. Out of 74 patients in the A HF group 8 (10,8%) did not complete the treatment and 2 of then died in 3rd and 4th week of treatment. The use of accelerated hyperfractionation does not improve the results of palliative teleradiotherapy in patients with locally advanced NSCLC without severe symptoms related to intrathoracic tumor. The treatment of choice in this group of patients os conventionally fractionated radiotherapy with a total dose of 50 Gy in 25 fractions in 5 week of treatment. (author)

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  20. Hyperfractionated conformal radiotherapy in locally advanced prostate cancer: results of a dose escalation study

    International Nuclear Information System (INIS)

    Forman, Jeffrey D.; Duclos, Marie; Shamsa, Falah; Porter, Arthur T.; Orton, Colin

    1996-01-01

    Purpose: This study was initiated to assess the incidence of chronic complications and histologic and biochemical control following hyperfractionated conformal radiotherapy in patients with locally advanced prostate cancer. Methods and Materials: Between October 1991 and October 1994, 49 patients with locally advanced prostate cancer were entered on the first two dose levels of a prospective dose-escalation study using hyperfractionated three dimensional conformal radiotherapy. The first 25 patients received a minimum tumor dose of 78 Gy to the prostate and seminal vesicles in 6 weeks at 1.3 Gy, b.i.d. No increase in chronic toxicity compared with conventional radiotherapy was noted; therefore, an additional 24 patients were treated to a minimum tumor dose of 82.8 Gy to the prostate and seminal vesicles in 7 weeks at 1.15 Gy, b.i.d. Toxicity was scored according to the Radiation Therapy Oncology Group morbidity grading scale. Efficacy was assessed through scheduled postradiation prostate specific antigen values and ultrasound-guided biopsies. The median follow-up for the entire group was 20 months. Results: The hyperfractionated external radiation was well tolerated with minimal acute morbidity. At 30 months, the actuarial probability of Grade 2 gastrointestinal toxicity was 17%. At 30 months, the actuarial probability of Grade 2 genitourinary toxicity was 16%. There was no statistically significant difference between the two dose levels. No Grade 3 or 4 gastrointestinal or genitourinary toxicity was noted. At 12 months, 84% of patients had a prostate specific antigen ≤ 4; and 53%; ≤ 1 ng/ml. At 12 months, 71% of patients had post radiation biopsies that were either negative (55%) or showed a marked therapeutic effect (16%). Conclusion: The use of hyperfractionated conformal radiotherapy facilitated dose escalation with no increase in chronic toxicity compared to standard doses. The initial tumor response based on prostate specific antigen measurements and

  1. Continuous hyperfractionated accelerated radiotherapy (chart) in localized cancer of the esophagus

    International Nuclear Information System (INIS)

    Powell, Melanie E.B.; Hoskin, Peter J.; Saunders, Michele I.; Foy, Christopher J.W.; Dische, Stanley

    1997-01-01

    Purpose: To assess the efficacy and toxicity of continuous hyperfractionated accelerated radiotherapy (CHART) in locoregional control compared with a historical group of patients treated with conventionally fractionated radical radiotherapy. Methods and Materials: Between 1985 and 1994, 54 patients with localized esophageal cancer were treated with CHART. Twenty-eight patients received CHART alone (54 Gy in 36 fractions over 12 consecutive days) and 15 were given intravenous mitomycin C and cisplatin on days 10 and 13, respectively. Eleven patients received 40.5 Gy in 27 fractions over 9 days, followed by a single high-dose-rate intraluminal brachytherapy insertion of 15 Gy at 1 cm. Results: Acute toxicity was well tolerated and dysphagia was improved in 35 patients (65%), with 28 (52%) eating a normal diet by week 12. This compares with an improvement in dysphagia score in 72% of the conventionally treated group. The median duration of relief of dysphagia was 7.8 months (range 0-41.4) in the CHART group compared with 5.5 months (range 0-48) in the controls. Strictures developed in 29 patients (61%) and 18 were confirmed on biopsy to be due to recurrent disease. Median survival was 12 months (range 0.5-112) in the CHART group and 15 months (range 3.6-56) in the control patients. Conclusion: CHART is well tolerated and achieves a high rate of local control. Palliation in the short overall treatment time of esophageal cancer is an advantage in these patients whose median survival is only 12 months

  2. Second Study of Hyper-Fractionated Radiotherapy

    Directory of Open Access Journals (Sweden)

    R. Jacob

    1999-01-01

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

  3. The hyperfractionation in the oropharynx carcinomas treatment: stages III and IV

    International Nuclear Information System (INIS)

    Pinto, L.H.J.

    1990-01-01

    From April 1986 until May 1989. 112 patients with stages III and IV oropharynx carcinomas were included in a protocol comparing the use of Hyperfractionation and Conventional Fractionation. The doses were 6600 rad in 33 fractions of 200 rad for the conventional fractionation and 7040 rad in 64 fractions, two fractions of 110 rad per day for the hyperfractionation. As of January 1990 an analysis was performed in 98 patients, with a median follow-up of 14 months. The probability of complete responses in the oropharynx was 74%, with 84% for the hyperfractionation and 64% for the conventional fractionation ( p < 0,05). Survival was improved in 42 months for those patients treated with hyperfractionation: 27% versus 8% (p < 0,05). In patients with lesions out of the base of the tongue and in those with Karnofsky performance status of 50%, 60% and 70%, survival was improved with the use of hyperfractionation (p = 0,02 and p 0,006 respectively. The study demonstrates the superiority of hyperfractionation over the classical fractionation in the treatment of patients with carcinoma of the oropharynx. (author)

  4. To hyperfractionate or not to hyperfractionate-Is it really a question?

    DEFF Research Database (Denmark)

    Eriksen, Jesper Grau; Merlano, Marco C

    2016-01-01

    Despite technical advances the last decade, patients with HPV/p16 negative head and neck cancer (being smokers and having affected performance and co-morbidities), still have a poor outcome after treatment. Hyperfractionated radiotherapy with concurrent cisplatin might be a reasonable way to purs...

  5. Hyperfractionated radiotherapy alone for clinical stage I nonsmall cell lung cancer

    International Nuclear Information System (INIS)

    Jeremic, Branislav; Shibamoto, Yuta; Acimovic, Ljubisa; Milisavljevic, Slobodan

    1997-01-01

    Purpose: Among patients with Stage I nonsmall cell lung cancer (NSCLC), those treated with conventional radiotherapy show poorer prognosis than those treated by surgery. To improve the prognosis of such patients, we have used hyperfractionated radiation therapy. Methods and Materials: Between 1988 and 1993, 49 patients were treated with hyperfractionated radiotherapy with 1.2 Gy twice daily to a total dose of 69.6 Gy. All patients were technically operable, but 29 had medical problems and 20 refused surgery. The median age and Karnofsky Performance Status was 63 years and 90, respectively. No patient received chemotherapy or immunotherapy. Prophylactic mediastinal irradiation was not given. Results: The median survival time was 33 months, and the 5-year survival rate was 30%. The rate at 5 years for freedom from each of relapse, local recurrence, mediastinal lymphnode metastasis, and distant metastasis was 41%, 55%, 89%, and 75%, respectively. Univariate analysis revealed that higher Karnofsky Performance Status score, absence of weight loss before treatment, and T1 stage were associated with better survival, although the T stage became insignificant on multivariate analysis. There were two Grade 3 acute toxicities and three Grade 3 late toxicities, but there was no Grade 4-5 toxicity. Conclusion: The results of this study compare favorably with those of most previous studies employing conventional fractionation. Further studies on hyperfractionation seem to be warranted for Stage I NSCLC

  6. Phase I and pharmacokinetic study of preirradiation chemotherapy with BCNU, cisplatin, etoposide, and accelerated radiation therapy in patients with high-grade glioma

    International Nuclear Information System (INIS)

    Rajkumar, S. Vincent; Buckner, Jan C.; Schomberg, Paula J.; Reid, Joel M.; Bagniewski, Pamela J.; Ames, Matthew M.; Cascino, Terrence L.; Marks, Randolph S.

    1998-01-01

    Purpose: We conducted a Phase I study of bischloroethylnitrosourea (BCNU), cisplatin, and oral etoposide administered prior to and during accelerated hyperfractionated radiation therapy in newly diagnosed high-grade glioma. Pharmacokinetic studies of oral etoposide were also done. Methods and Materials: Patients started chemotherapy after surgery but prior to definitive radiation therapy (160 cGy twice daily x 15 days; 4800 cGy total). Initial chemotherapy consisted of BCNU 40 mg/m 2 days 1-3, cisplatin 30 mg/m 2 days 1-3 and 29-31, and etoposide 50 mg orally days 1-14 and 29-42, repeated in 8 weeks concurrent with radiation therapy. BCNU 200 mg/m 2 every 8 weeks x 4 cycles was given after radiation therapy. Results: Sixteen patients, 5 with grade 3 anaplastic astrocytoma and 11 with glioblastoma were studied. Grade 3-4 leukopenia (38%) and thrombocytopenia (31%) were dose-limiting. Other toxicities were anorexia (81%), nausea (94%), emesis (56%), alopecia (88%), and ototoxicity (38%). The maximum tolerated dose was BCNU 40 mg/m 2 days 1-3, cisplatin 20 mg/m 2 days 1-3 and 29-31, and oral etoposide 50 mg days 1-21 and 29-49 prior to radiation therapy and repeated in 8 weeks with the start of radiation therapy followed by BCNU 200 mg/m 2 every 8 weeks for 4 cycles. Median time to progression and survival were 13 and 14 months respectively. Responses occurred in 2 of 9 (22%) patients with evaluable disease. In pharmacokinetic studies, all patients achieved plasma concentrations of >0.1 μg/ml etoposide (the in vitro radiosensitizing threshold), following a 50 mg oral dose. The mean ± SD 2 hr and 6 hr plasma concentrations were 0.92 ± 0.43 μg/ml and 0.36 ± 0.12 μg/ml, respectively. Estimated duration of exposure to >0.1 μg/ml etoposide was 10-17 hr. Conclusions: Preirradiation chemotherapy with BCNU, cisplatin, and oral etoposide with accelerated hyperfractionated radiation therapy in high-grade gliomas is feasible and merits further investigation. Sustained

  7. Hyperfractionated Accelerated Radiotherapy (HART) for Anaplastic Thyroid Carcinoma: Toxicity and Survival Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dandekar, Prasad [Head and Neck/Thyroid Unit, Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Harmer, Clive; Barbachano, Yolanda [Department of Clinical Research and Development, Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Rhys-Evans, Peter; Harrington, Kevin; Nutting, Christopher [Head and Neck-Thyroid Unit, Royal Marsden NHS Foundation Trust, Chelsea, London (United Kingdom); Newbold, Kate [Head and Neck/Thyroid Unit, Royal Marsden NHS Foundation Trust, Sutton, Surrey (United Kingdom); Consultant Clinical Oncologist, Royal Marsden NHS Foundation Trust, Chelsea, London (United Kingdom)

    2009-06-01

    Purpose: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive cancers, and the current protocol of hyperfractionated accelerated radiotherapy was initiated to improve survival while limiting toxicities. Methods and Materials: All patients with ATC from 1991 to 2002 were accrued and received megavoltage radiotherapy from the mastoid processes to the carina up to 60 Gy in twice-daily fractions of 1.8 and 2 Gy, 6 hours apart. Results: Thirty-one patients were accrued with a median age of 69 years, and 55% were women. Debulking was performed in 26%, and total thyroidectomy, in 6%, whereas 68% received radical radiotherapy alone. Local control data were available for 27 patients: 22% had a complete response, 26% had a partial response, 15% showed progressive disease, and 37% showed static disease. Median overall survival for all 31 patients was 70 days (95% confidence interval, 40-99). There was no significant difference in median survival between patients younger (70 days) and older than 70 years (42 days), between men (70 days) and women (49days), and between patients receiving postoperative radiotherapy (77 days) and radical radiotherapy alone (35 days). Grade III or higher skin erythema was seen in 56% patients; desquamation in 21%; dysphagia in 74%; and esophagitis in 79%. Conclusion: The current protocol failed to offer a significant survival benefit, was associated with severe toxicities, and thus was discontinued. There is a suggestion that younger patients with operable disease have longer survival, but this would require a larger study to confirm it.

  8. Concurrent chemotherapy, accelerated hyperfractionated split course radiation therapy and surgery for esophageal cancer

    International Nuclear Information System (INIS)

    Becker, M.; Adelstein, D.J.; Rice, T.W.; Kirk, M.A. van; Kirby, T.J.; Koka, A.; Tefft, M.; Zuccaro, G.

    1996-01-01

    Purpose/Objectives: A prospective single arm trial was undertaken to determine the toxicity, the clinical and pathologic response rates and survival for patients with esophageal cancer treated with concurrent chemotherapy(CC) and accelerated hyperfractionated split course radiotherapy(AHFSCRT) followed by surgical resection. Materials and Methods: A prospective single arm trial was conducted between 1991 and 1995 for patients with T1-4, N0-1, M1(celiac or supraclavicular) adenocarcinoma or squamous cell carcinoma of the esophagus. A total of 74 patients entered onto the protocol, and 72 are eligible and evaluable. Neoadjuvant chemotherapy consisting of two cycles of Cisplatin(20mg/m2/day) and 5-fluorouracil (1000mg/m2/day) given concurrently with AHSCRT 1.5Gy BID (at least 6 hour between fractions) to 2400cGy and 2100cGy, with cycles 1 and 2 of chemotherapy respectively. Patients were staged/restaged with barium esophagram(BS), computerized tomograph of the chest(CAT), upper endoscopy(EGD) with ultrasound (EUS) and evaluated for surgical resection. A single adjuvant course of concurrent chemotherapy and AHSCRT was delivered for those patients who were pathologic partial responders(pPR). Results: Initial clinical staging revealed one patient stage I, 24 patients' stage IIA, 2 patients' with stage IIB, 34 patients' with stage III and 6 patients' with stage IV disease. Five patients could not be staged adequately. The toxicity to neoadjuvant therapy included nausea in 85% (grade 3 in 1%), esophagitis 90% (grade 3 in 18%), neutropenia grade 3 of 43% (with fever 17%), thrombocytopenia grade 4 in 10% and nephrotoxicity in 8%. There was one death due to neoadjuvant therapy. Of the 72 evaluable patients, 67 underwent surgery, and 65(90%) had a complete resection. Twenty-seven percent were pathologic complete responders, including 22% with adenocarcinoma and 36% with squamous cell carcinoma. Complete pathologic response after neoadjuvant therapy was accurately predicted by

  9. Hyperfractionated radiation in combination with local hyperthermia in the treatment of advanced squamous cell carcinoma of the head and neck: a phase I-II study

    International Nuclear Information System (INIS)

    Amichetti, Maurizio; Romano, Mario; Busana, Lucia; Bolner, Andrea; Fellin, Gianni; Pani, Giuseppe; Tomio, Luigi; Valdagni, Riccardo

    1997-01-01

    Twenty-seven patients with cervical metastases from squamous cell head and neck tumours were treated with hyperfractionated XRT (total dose 69.60-76.80 Gy, 1.2 Gy b.i.d. five times a week) combined with a total of two to six sessions of superficial external HT. Acute local toxicity was mild; as major acute side effects, only one ulceration was recorded. No severe late side effects were observed. Late toxicity was similar to that observed in our previous studies with the combination of heat and radiation. Nodal complete response was observed in 77% of patients, partial response was observed in 15% of patients and no change was observed in 8% of patients. Five-year actuarial nodal control was 64.5 ± 19% and 5-year actuarial survival was 24 ± 10%. The treatment of nodal metastases from head and neck tumours with the combination of HT and hyperfractionated XRT is feasible with an acceptable acute and late toxicity profile

  10. Local control of T3 carcinomas after accelerated fractionation: a look at the 'gap'

    International Nuclear Information System (INIS)

    Wang, C.C.; Efird, Jimmy; Nakfoor, Bruce; Martins, Patricia

    1996-01-01

    Purpose: To study the effects of midcourse treatment break or gaps related to the local control of T3 carcinoma of the oropharynx and larynx following accelerated hyperfractionated radiation therapy. Methods and Materials: All patients were treated at the Massachusetts General Hospital from 1979 through 1994 with treatment consisting of 1.6 Gy per fraction, two fractions a day for the treatment of T3 carcinoma of the oropharynx and larynx. They were entered in the head and neck data base. Their treatment dates, treatment breaks, and doses vs. local control were analyzed and compared. A p-value of 0.05 was considered statistically significant. Results: A total of 162 patients were available for review. Due to the acute severe mucosal effects, most of the patients required a midcourse pause or 'break' after a dose of 38.4-48 Gy before treatment could be resumed and completed. The data indicate that (a) prolongation of the treatment gap for more than 14 days, (b) total treatment course longer than 45 days, (c) total dose less than 67 Gy, and (d) male gender adversely affected local control. In spite of the gaps, the female patients with advanced carcinomas enjoyed the benefits of improved local control after the accelerated hyperfractionated radiation therapy. Conclusions: Accelerated hyperfractionation radiation therapy using 1.6 Gy per fraction/twice-a-day (b.i.d.) for a total dose of 70.4 Gy in 6 weeks is effective in achieving high local control of T3 squamous cell carcinoma of the oropharynx and larynx. The midcourse treatment gap should be as short as possible with the projected total dose and time. Should the gaps be unduly prolonged due to various circumstances, further increase in the total dose, for example, 72-75 Gy, and/or increase of the fraction sizes, for example, 1.8-2.0 Gy/f b.i.d. after the gap may be necessary to compensate for the adverse effects of the tumor regeneration from the prolonged gap

  11. Early termination of prostate cancer hyperfractionated dose escalation study

    International Nuclear Information System (INIS)

    Forman, Jeffrey D; Porter, Arthur T; Kocheril, Paul; Grignon, David; Orton, Colin

    1996-01-01

    Purpose: This study was initiated to determine the maximum tolerable dose of hyperfractionated radiation in patients with locally advanced prostate cancer. Materials and Methods: Forty-nine patients with locally advanced prostate cancer (T3-T4 Nx, 0, 1 M0 and/or Gleason Score ≥ 8) were treated on the first two steps of a prospective dose-escalation study using hyperfractionated conformal radiotherapy. The first 25 patients received a minimum dose of 78Gy to the clinical tumor volume (CTV) including the prostate, seminal vesicle and a 5mm margin at 1.3Gy b.i.d. The second group (24 patients) received a minimum dose to the CTV of 82.8Gy at 1.15Gy b.i.d. Twenty eight patients received neo-adjuvant hormonal therapy in conjunction with their radiation (8 of 25 patients at 78Gy and 20 of 24 patients at 82.8Gy). Toxicity was scored according to the RTOG grading scale. Efficacy was evaluated by PSA levels and ultrasound guided biopsies. Median follow up was 36 and 18 months for the 78Gy and 82.8Gy dose levels, respectively. Results: No grade 3 or 4 gastrointestinal (GI) or genitourinary (GU) toxicity was noted. At 36 months, the actuarial probability of Grade 2 GI and GU toxicity were 16 and 20%, respectively. Twelve to 18 months following radiation, 41 patients (86%) underwent ultrasound guided biopsy. At 78Gy, 60% of 20 patients had a biopsy which was negative or showed a marked therapeutic effect. At 82.8Gy, these combined rates were 95% in the 21 patients who had biopsies. Nine patients (50%) who did not receive neo-adjuvant hormones had positive biopsies. No patient who received neo-adjuvant hormones plus 78Gy (5 patients) or 82.8Gy (18 patients) had a positive biopsy. Conclusion: Proceeding to the next dose level (87.4Gy) was justified by the lack of severe chronic toxicity. However, in view of the high rate of histologic sterilization when hyperfractionated irradiation was given in conjunction with neo-adjuvant hormonal therapy, it was felt to be unethical to

  12. Hyperfractionated abdominal radiotherapy in children. Efficacy and tolerance in 13 cases

    International Nuclear Information System (INIS)

    Lagrange, J.L.; Roullet, B.; Cosset, J.M.; Sarrazin, D.; Lemerle, J.

    1984-01-01

    The experience at IGR has shown that hyperfractionation, especially abdominal has been well tolerated in adult patients. This finding led to employ this technic in the pediatric population who had failed standard treatment. An experience with hyperfractionated radiotherapy of the abdomen and liver in children, is reported. The children were treated 4 days per week, receiving 5 fractions daily of 0.7 Gy, with a 2 hours interval between each treatment. A total dose of 28 Gy was delivered in 40 fractions over 12 days. A second course of irradiation was delivered in 5 patients, 3 with abdominal treatment and 2 with liver irradiation. The vital organs were shielded with blocks at normal dose tolerance levels. The results are encouraging since an immediate efficacy was observed in 8 of 13 patients. Long term survivals were observed in 4 patients with nephroblastomas and 1 patient with a hepatoblastoma. On the other hand acute gastrointestinal tolerance seemed less good in the children than previously observed in the adults. Five radiation hepatitis appeared, immediately after the irradiation, whom four children irradiated to the entire abdomen [fr

  13. Late course accelerated fractionation in radiotherapy of esophageal carcinoma

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  14. Accelerator and radiation physics

    CERN Document Server

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  15. Angiosarcoma after breast-conserving therapy: experience with hyperfractionated radiotherapy

    International Nuclear Information System (INIS)

    Feigenberg, Steven J.; Price Mendenhall, Nancy; Reith, John D.; Ward, Jon R.; Copeland, Edward M.

    2002-01-01

    Purpose: To report our promising results of hyperfractionated radiotherapy (RT) in conjunction with surgery for angiosarcoma occurring after breast-conserving therapy for early-stage breast cancer. Methods and Materials: Since 1997, 3 cases of angiosarcoma after breast-conserving therapy have been managed at the University of Florida. The histologic specimens in each case were reviewed and graded by one of us (J.D.R.). Results: Explosive growth of discolored skin lesions coincident with histologic evidence of angiosarcoma characterized all 3 cases but was preceded by a fairly indolent period (almost 2 years) of atypical vascular hyperplasia in 2 patients. All 3 patients were treated initially with radical surgery for the angiosarcoma, but extensive recurrences were noted within 1 to 2 months of surgery. Because of the extremely rapid growth noted before and after surgery, hyperfractionated RT was used. Two of the patients underwent planned resection after RT, and neither specimen demonstrated any evidence of high-grade angiosarcoma. All 3 patients were alive without any recurrent disease 22, 38, and 39 months after treatment. Conclusions: Hyperfractionated irradiation appears to be effective treatment for rapidly proliferating angiosarcoma. For previously untreated angiosarcoma, we now recommend hyperfractionated RT followed by surgery to enhance disease control and remove as much reirradiated tissue as possible

  16. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.; van de Geijn, J.; Goffman, T. (ROB, DCT, NCI, NIH, Bethesda, Maryland 20892 (US))

    1991-05-01

    In the conventional linear--quadratic model of single-dose response, the {alpha} and {beta} terms reflect lethal damage created {ital during} the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD.

  17. Extra lethal damage due to residual incompletely repaired sublethal damage in hyperfractionated and continuous radiation treatment

    International Nuclear Information System (INIS)

    Chen, J.; van de Geijn, J.; Goffman, T.

    1991-01-01

    In the conventional linear--quadratic model of single-dose response, the α and β terms reflect lethal damage created during the delivery of a dose, from two different presumed molecular processes, one linear with dose, the other quadratic. With the conventional one-fraction-per-day (or less) regimens, the sublethal damage (SLD), presumably repairing exponentially over time, is essentially completely fixed by the time of the next dose of radiation. If this assumption is true, the effects of subsequent fractions of radiation should be independent, that is, there should be little, if any, reversible damage left from previous fractions, at the time of the next dose. For multiple daily fractions, or for the limiting case, continuous radiation, this simplification may overlook damaged cells that have had insufficient time for repair. A generalized method is presented for accounting for extra lethal damage (ELD) arising from such residual SLD for hyperfractionation and continuous irradiation schemes. It may help to predict differences in toxicity and tumor control, if any, obtained with ''unconventional'' treatment regimens. A key element in the present model is the finite size and the dynamic character of the pool of sublethal damage. Besides creating the usual linear and quadratic components of lethal damage, each new fraction converts a certain fraction of the existing SLD into ELD, and creates some new SLD

  18. Radiation therapy for hypopharyngeal carcinoma. Impact of fractionation on treatment outcome

    International Nuclear Information System (INIS)

    Niibe, Yuzuru; Karasawa, Katsuyuki; Igaki, Hiroshi; Miyashita, Hisao; Tanaka, Yoshiaki

    2003-01-01

    The purpose of the current study was to evaluate the impact of fractionation on the treatment outcome of radiation therapy for hypopharyngeal carcinoma. Thirty-six inoperable or operation-refused hypopharyngeal patients were treated with curative-intended radiation therapy between 1976 and May 2001. Seventeen patients were treated with conventional radiation therapy, 1.8-2.0 Gy per fraction, totaling 64.0 Gy (conventional fractionation (CF) group), and 19 were treated with hyperfractionated radiation therapy, 1.2 Gy per fraction, totaling 74.4 Gy (hyperfractionation (HF) group). The radiation response of the two groups at the end of radiation therapy was almost the same. However, the 2-year local control rates of the HF and CF groups were 59.0% and 26.1% (p=0.012), respectively, a statistically significant differences. Moreover, multivariate analysis showed that HF was an independent prognostic factor for local control. Hyperfractionated radiation therapy was superior to conventional radiation therapy for local control. Local control of hypopharyngeal carcinoma correlated with laryngeal preservation, suggesting that hyperfractionated radiation therapy for hypopharyngeal carcinoma could be beneficial for patient quality of life (QOL). (author)

  19. Phase II Trial of Hyperfractionated Intensity-Modulated Radiation Therapy and Concurrent Weekly Cisplatin for Stage III and IVa Head-and-Neck Cancer

    International Nuclear Information System (INIS)

    Maguire, Patrick D.; Papagikos, Michael; Hamann, Sue; Neal, Charles; Meyerson, Martin; Hayes, Neil; Ungaro, Peter; Kotz, Kenneth; Couch, Marion; Pollock, Hoke; Tepper, Joel

    2011-01-01

    Purpose: To investigate a novel chemoradiation regimen designed to maximize locoregional control (LRC) and minimize toxicity for patients with advanced head-and-neck squamous cell carcinoma (HNSCC). Methods and Materials: Patients received hyperfractionated intensity modulated radiation therapy (HIMRT) in 1.25-Gy fractions b.i.d. to 70 Gy to high-risk planning target volume (PTV). Intermediate and low-risk PTVs received 60 Gy and 50 Gy, at 1.07, and 0.89 Gy per fraction, respectively. Concurrent cisplatin 33 mg/m 2 /week was started Week 1. Patients completed the Quality of Life Radiation Therapy Instrument pretreatment (PRE), at end of treatment (EOT), and at 1, 3, 6, 9, and 12 months. Overall survival (OS), progression-free (PFS), LRC, and toxicities were assessed. Results: Of 39 patients, 30 (77%) were alive without disease at median follow-up of 37.5 months. Actuarial 3-year OS, PFS, and LRC were 80%, 82%, and 87%, respectively. No failures occurred in the electively irradiated neck and there were no isolated neck failures. Head and neck QOL was significantly worse in 18 of 35 patients (51%): mean 7.8 PRE vs. 3.9 EOT. By month 1, H and N QOL returned near baseline (mean 6.2, SD = 1.7). The most common acute Grade 3+ toxicities were mucositis (38%), fatigue (28%), dysphagia (28%), and leukopenia (26%). Conclusions: Hyperfractionated IMRT with low-dose weekly cisplatin resulted in good LRC with acceptable toxicity and QOL. Lack of elective nodal failures despite very low dose per fraction has led to an attempt to further minimize toxicity by reducing elective nodal doses in our subsequent protocol.

  20. Radiative damping in plasma-based accelerators

    Directory of Open Access Journals (Sweden)

    I. Yu. Kostyukov

    2012-11-01

    Full Text Available The electrons accelerated in a plasma-based accelerator undergo betatron oscillations and emit synchrotron radiation. The energy loss to synchrotron radiation may seriously affect electron acceleration. The electron dynamics under combined influence of the constant accelerating force and the classical radiation reaction force is studied. It is shown that electron acceleration cannot be limited by radiation reaction. If initially the accelerating force was stronger than the radiation reaction force, then the electron acceleration is unlimited. Otherwise the electron is decelerated by radiative damping up to a certain instant of time and then accelerated without limits. It is shown that regardless of the initial conditions the infinite-time asymptotic behavior of an electron is governed by a self-similar solution providing that the radiative damping becomes exactly equal to 2/3 of the accelerating force. The relative energy spread induced by the radiative damping decreases with time in the infinite-time limit. The multistage schemes operating in the asymptotic acceleration regime when electron dynamics is determined by the radiation reaction are discussed.

  1. Phase II, two-arm RTOG trial (94-11) of bischloroethyl-nitrosourea plus accelerated hyperfractionated radiotherapy (64.0 or 70.4 Gy) based on tumor volume (> 20 or ≤ 20 cm2, respectively) in the treatment of newly-diagnosed radiosurgery-ineligible glioblastoma multiforme patients

    International Nuclear Information System (INIS)

    Coughlin, C.; Scott, C.; Langer, C.; Coia, L.; Curran, W.; Rubin, P.

    2000-01-01

    Purpose: To compare survivorship, and acute and delayed toxicities following radiation therapy (RT) of radiosurgery-ineligible glioblastoma multiforme (GBM) patients treated with tumor volume-influenced, high-dose accelerated, hyperfractionated RT plus bischloroethyl-nitrosourea (BCNU), using prior RTOG malignant glioblastoma patients as historical controls. Methods and Materials: One hundred four of 108 patients accrued from June 1994 through May 1995 from 26 institutions were analyzable. Patients were histologically confirmed with GBM, and previously untreated. Treatment assignment (52 patients/arm) was based on tumor mass (TM), defined as the product of the maximum diameter and greatest perpendicular dimension of the titanium-gadolinium-enhanced postoperative MRI: Arm A, 64 Gy, TM > 20 cm 2 ; or Arm B, 70.4 Gy, TM ≤ 20 cm 2 . Both Arms A and B received BCNU (80 mg/m 2 , under hyperhydration) days 1-3, 56-58, then 4 cycles, each 8 weeks, for a total of 6 treatment series. Results: During the 24 months immediately post-treatment, the overall median survival was 9.1 months in Arm A (64 Gy) and 11.0 months in Arm B (70.4 Gy). Median survival in recursive partitioning analysis (RPA) Class III/IV was 10.4 months in Arm A and 12.2 months in Arm B, while RPA Class V/VI was 7.6 months in Arm A and 6.1 months in Arm B. There were no grade 4 neurological toxicities in Arm A; 2 grade 4 neurological toxicities were observed in Arm B (1 motor deficit, 1 necrosis at 157 days post-treatment). Conclusion: This strategy of high-dose, accelerated hyperfractionated radiotherapy shortens overall RT treatment times while allowing dose escalation, and it provides the potential for combination with currently available, as well as newer, chemotherapy agents. Survival is comparable with previously published RTOG data, and toxicities are within acceptable limits.

  2. Angiosarcoma after breast-conserving therapy: long-term outcomes with hyperfractionated radiotherapy.

    Science.gov (United States)

    Palta, Manisha; Morris, Christopher G; Grobmyer, Stephen R; Copeland, Edward M; Mendenhall, Nancy P

    2010-04-15

    With breast-conserving therapy (BCT) as the standard of care for patients with noninvasive and early stage invasive breast cancer, a small incidence of post-BCT angiosarcoma has emerged. The majority of therapeutic interventions have been unsuccessful. To the authors' knowledge, there is no consensus in the medical literature to date regarding the treatment of this malignancy. The current study was conducted to report the long-term outcomes of a novel approach using hyperfractionated and accelerated radiotherapy (HART) for angiosarcoma developing after BCT. The authors retrospectively reviewed the outcomes of 14 patients treated with HART with or without surgery at the University of Florida between November 1997 and March 2006 for angiosarcoma that developed after BCT. At the time of last follow-up, 9 patients had remained continuously without evidence of disease for a median of 61 months after HART (range, 36-127 months). Five patients had further manifestations of angiosarcoma after HART at a median of 1 month (range, 1-28 months): 3 with progressive pulmonary and/or mediastinal disease that was likely present before HART and 2 with local or regional disease extension. Progression-free survival rates for the 14 patients at 2 years and 5 years were 71% and 64%, respectively. The overall and cause-specific survival rates were both 86% at 2 years and 5 years. To the best of the authors' knowledge, HART with or without subsequent surgery, as documented in the current series, is the first approach to provide a high rate of local control, disease-free survival, and overall survival after the development of post-BCT angiosarcoma. The authors believe the success noted with this approach is related to both the hyperfractionation and acceleration of the RT. (c) 2010 American Cancer Society.

  3. Comparison of single, fractionated and hyperfractionated irradiation on the development of normal tissue damage in rat lung

    International Nuclear Information System (INIS)

    Giri, P.G.S.; Kimler, B.F.; Giri, U.P.; Cox, G.G.; Reddy, E.K.

    1985-01-01

    The effect of fractionated thoracic irradiation on the development of normal tissue damage in rats was compared to that produced by single doses. Animals received a single dose of 15 Gy, 30 Gy in 10 daily fractions of 3 Gy each (fractionation), or 30 Gy in 30 fractions of 1 Gy each 3 times a day (hyperfractionation). The treatments produced minimal lethality since a total of only 6 animals died between days 273 and 475 after the initiation of treatment, with no difference in survival observed between the control and any of the 3 treated groups. Despite the lack of lethality, evidence of lung damage was obtained by histological examination. Animals that had received either single doses or fractionated doses had more of the pulmonary parenchyma involved than did animals that had received hyperfractionated doses. The authors conclude that, in the rat lung model, a total radiation dose of 30 Gy fractionated over 14 days produces no more lethality nor damage to lung tissue than does 15 Gy delivered as a single dose. However, long-term effects as evidenced by deposits of collagen and development of fibrosis are significantly reduced by hyperfractionation when compared to single doses and daily fractionation

  4. Topics in radiation at accelerators: Radiation physics for personnel and environmental protection

    International Nuclear Information System (INIS)

    Cossairt, J.D.

    1993-11-01

    This report discusses the following topics: Composition of Accelerator Radiation Fields; Shielding of Electrons and Photons at Accelerators; Shielding of Hadrons at Accelerators; Low Energy Prompt Radiation Phenomena; Induced Radioactivity at Accelerators; Topics in Radiation Protection Instrumentation at Accelerators; and Accelerator Radiation Protection Program Elements

  5. Intensified hyperfractionated accelerated radiotherapy limits the additional benefit of simultaneous chemotherapy--results of a multicentric randomized German trial in advanced head-and-neck cancer.

    Science.gov (United States)

    Staar, S; Rudat, V; Stuetzer, H; Dietz, A; Volling, P; Schroeder, M; Flentje, M; Eckel, H E; Mueller, R P

    2001-08-01

    To demonstrate the efficacy of radiochemotherapy (RCT) as the first choice of treatment for advanced unresectable head-and-neck cancer. To prove an expected benefit of simultaneously given chemotherapy, a two-arm randomized study with hyperfractionated accelerated radiochemotherapy (HF-ACC-RCT) vs. hyperfractionated accelerated radiotherapy (HF-ACC-RT) was initiated. The primary endpoint was 1-year survival with local control (SLC). Patients with Stage III and IV (UICC) unresectable oro- and hypopharyngeal carcinomas were randomized for HF-ACC-RCT with 2 cycles of 5-FU (600 mg/m(2)/day)/carboplatinum (70 mg/m(2)) on days 1--5 and 29--33 (arm A) or HF-ACC-RT alone (arm B). In both arms, there was a second randomization for testing the effect of prophylactically given G-CSF (263 microg, days 15--19) on mucosal toxicity. Total RT dose in both arms was 69.9 Gy in 38 days, with a concomitant boost regimen (weeks 1--3: 1.8 Gy/day, weeks 4 and 5: b.i.d. RT with 1.8 Gy/1.5 Gy). Between July 1995 and May 1999, 263 patients were randomized (median age 56 years; 96% Stage IV tumors, 4% Stage III tumors). This analysis is based on 240 patients: 113 patients with RCT and 127 patients with RT, qualified for protocol and starting treatment. There were 178 oropharyngeal and 62 hypopharyngeal carcinomas. Treatment was tolerable in both arms, with a higher mucosal toxicity after RCT. Restaging showed comparable nonsignificant different CR + PR rates of 92.4% after RCT and 87.9% after RT (p = 0.29). After a median observed time of 22.3 months, l- and 2-year local-regional control (LRC) rates were 69% and 51% after RCT and 58% and 45% after RT (p = 0.14). There was a significantly better 1-year SLC after RCT (58%) compared with RT (44%, p = 0.05). Patients with oropharyngeal carcinomas showed significantly better SLC after RCT (60%) vs. RT (40%, p = 0.01); the smaller group of hypopharyngeal carcinomas had no statistical benefit of RCT (p = 0.84). For both tumor locations

  6. Topics in radiation at accelerators: Radiation physics for personnel and environmental protection

    International Nuclear Information System (INIS)

    Cossairt, J.D.

    1996-10-01

    In the first chapter, terminology, physical and radiological quantities, and units of measurement used to describe the properties of accelerator radiation fields are reviewed. The general considerations of primary radiation fields pertinent to accelerators are discussed. The primary radiation fields produced by electron beams are described qualitatively and quantitatively. In the same manner the primary radiation fields produced by proton and ion beams are described. Subsequent chapters describe: shielding of electrons and photons at accelerators; shielding of proton and ion accelerators; low energy prompt radiation phenomena; induced radioactivity at accelerators; topics in radiation protection instrumentation at accelerators; and accelerator radiation protection program elements

  7. Prospective evaluation of delayed central nervous system (CNS) toxicity of hyperfractionated total body irradiation (TBI)

    International Nuclear Information System (INIS)

    Wenz, Frederik; Steinvorth, Sarah; Lohr, Frank; Fruehauf, Stefan; Wildermuth, Susanne; Kampen, Michael van; Wannenmacher, Michael

    2000-01-01

    Purpose: Prospective evaluation of chronic radiation effects on the healthy adult brain using neuropsychological testing of intelligence, attention, and memory. Methods and Materials: 58 patients (43 ± 10 yr) undergoing hyperfractionated total body irradiation (TBI) (TBI, 14.4 Gy, 12 x 1.2 Gy in 4 days) before bone marrow or peripheral blood stem cell transplantation were prospectively included. Twenty-one recurrence-free long-term survivors were re-examined 6-36 months (median 27 months) after completion of TBI. Neuropsychological testing included assessment of general intelligence, attention, and memory using normative, standardized psychometric tests. Mood status was controlled, as well. Test results are given as IQ scores (population mean 100) or percentiles for attention and memory (population mean 50). Results: The 21 patients showed normal baseline test results of IQ (101 ± 13) and attention (53 ± 28), with memory test scores below average (35 ± 21). Test results of IQ (98 ± 17), attention (58 ± 27), and memory (43 ± 28) showed no signs of clinically measurable radiation damage to higher CNS (central nervous system) functions during the follow-up. The mood status was improved. Conclusion: The investigation of CNS toxicity after hyperfractionated TBI showed no deterioration of test results in adult recurrence-free patients with tumor-free CNS. The median follow-up of 27 months will be extended.

  8. Randomized phase III trial of concurrent chemoradiotherapy vs accelerated hyperfractionation radiotherapy in locally advanced head and neck cancer

    International Nuclear Information System (INIS)

    Chitapanarux, Imjai; Kamnerdsupaphon, Pimkhuan; Pukanhapan, Nantaka; Tharavichitkul, Ekkasit; Vongtama, Roy

    2013-01-01

    The aim of this study was to compare the efficacy and safety of concurrent chemoradiotherapy (CCRT) vs accelerated hyperfractionation with concomitant boost (CCB) as a primary treatment for patients with Stage III-IV squamous cell carcinoma of head and neck (SCCHN). A total of 85 non-metastatic advanced SCCHN patients were accrued from January 2003 to December 2007. Of these, 48 and 37 patients received CCRT and CCB, respectively. The patients were randomized to receive either three cycles of carboplatin and 5-fluorouracil plus conventional radiotherapy (CCRT, 66 Gy in 6.5 weeks) or hybrid accelerated radiotherapy (CCB, 70 Gy in 6 weeks). The primary endpoint was determined by locoregional control rate. The secondary endpoints were overall survival and toxicity. With a median follow-up of 43 months (range, 3-102), the 5-year locoregional control rate was 69.6% in the CCRT arm vs 55.0% in the CCB arm (P = 0.184). The 5-year overall survival rate was marginally significantly different (P = 0.05): 76.1% in the CCRT arm vs 63.5% in the CCB arm. Radiotherapy treatment interruptions of more than three days were 60.4% and 40.5% in the CCRT arm and CCB arm, respectively. The median total treatment time was 55.5 days in the CCRT arm and 49 days in the CCB arm. The rate of Grade 3 - 4 acute mucositis was significantly higher in the CCB arm (67.6% vs 41.7%, P = 0.01), but no high grade hematologic toxicities were found in the CCB arm (27.2% vs 0%). CCRT has shown a trend of improving outcome over CCB irradiation in locoregionally advanced head and neck cancer. (author)

  9. Gemcitabine, cisplatin, and hyperfractionated accelerated radiotherapy for locally advanced non-small cell lung cancer.

    Science.gov (United States)

    Zwitter, Matjaz; Kovac, Viljem; Smrdel, Uros; Strojan, Primoz

    2006-09-01

    Due to potent radiosensitization and potential serious or fatal toxicity, concurrent gemcitabine and irradiation should only be applied within clinical trials. We here present experience from a phase I-II clinical trial for patients with locally advanced non-small cell lung cancer (NSCLC) treated with hyperfractionated accelerated radiotherapy and concurrent low-dose gemcitabine. Eligible patients had locally advanced inoperable NSCLC without pleural effusion, Eastern Cooperative Oncology Group performance status 0-1, were chemotherapy naïve and had no previous radiotherapy to the chest, and had adequate hematopoietic, liver, and kidney function. Routine brain computed tomography was not performed, and positron emission tomography/computed tomography was not available. Treatment consisted of three parts: induction chemotherapy with gemcitabine and cisplatin in standard doses, local treatment with concurrent chemotherapy and radiotherapy, and consolidation chemotherapy. Patients were irradiated with opposed AP-PA and oblique fields, using 2.5-D treatment planning. Although corrections for inhomogeneous tissue were made, volume of total lung receiving > or =20 Gy (V20) could not be determined. The trial started as phase I, aimed to determine the dose-limiting toxicity and maximal tolerated dose (MTD) for concurrent hyperfractionated radiotherapy (1.4 Gy twice daily) and gemcitabine 55 mg/m twice weekly as a radiosensitizer. Phase II of the trial then continued at the level of MTD. Twenty-eight patients with NSCLC, nine patients with stage IIIA, 16 patients with IIIB, and three patients with an inoperable recurrence after previous surgery, entered the trial. The first 12 patients entered Phase I of the trial at the initial level of 42 Gy in 30 fractions in 3 weeks. Dose-limiting toxicity was acute esophagitis; 47.6 Gy in 34 fractions in 3.5 weeks was the MTD for this regimen of concurrent chemotherapy and radiotherapy. In phase II of the trial, this dose was applied

  10. Hyperfractionated radiation therapy for incompletely resected supratentorial low-grade glioma. A phase II study

    International Nuclear Information System (INIS)

    Jeremic, B.; Milicic, B.; Stojanovic, M.; Nikolic, N.; Dagovic, A.; Shibamoto, Y.; Grujicic, D.

    1998-01-01

    Background and purpose: In order to investigate the feasibility, toxicity and antitumor efficacy of hyperfractionated radiation therapy, 37 adult patients with incompletely resected supratentorial low-grade glioma were entered into a phase II study. Materials and methods: The radiation therapy dose was 55 Gy in 50 fractions in 25 treatment days over 5 weeks to the tumor plus a 2-cm margin, with an additional 17.6 Gy given in 16 fractions in 8 treatment days over 1.5 weeks to the tumor plus a 1-cm margin, using 1.1 Gy b.i.d. fractionation with a 6 h interfraction interval. The total tumor dose was 72.6 Gy in 66 fractions in 33 treatment days over 6.5 weeks. Results: The median survival time (MST) for all 37 patients has not yet been attained, while 5- and 7-year survival rates were 75% and 69%, respectively. The median time to tumor progression (MTP) has also not yet been attained, while 5- and 7-year progression-free survival (PFS) rates were both 70%. There was no difference in survival or PFS regarding histology, although patients with oligodendroglioma and mixed glioma had similar survival, both being higher than that of ordinary astrocytoma. On univariate analysis of potential prognostic factors, age, Karnofsky performance status (KPS), neurologic status and extent of surgery were found to influence survival. The toxicity of HFX RT was generally assessed as mild to moderate. Conclusion: HFX RT is feasible with mild to moderate toxicity. Further studies are warranted with more patients and longer follow-up before testing it against standard fractionation RT in this patient population. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  12. Intensified hyperfractionated accelerated radiotherapy limits the additional benefit of simultaneous chemotherapy--results of a multicentric randomized German trial in advanced head-and-neck cancer

    International Nuclear Information System (INIS)

    Staar, Susanne; Rudat, Volker; Stuetzer, Hartmut; Dietz, Andreas; Volling, Peter; Schroeder, Michael; Flentje, Michael; Eckel, Hans Edmund; Mueller, Rolf-Peter

    2001-01-01

    Purpose: To demonstrate the efficacy of radiochemotherapy (RCT) as the first choice of treatment for advanced unresectable head-and-neck cancer. To prove an expected benefit of simultaneously given chemotherapy, a two-arm randomized study with hyperfractionated accelerated radiochemotherapy (HF-ACC-RCT) vs. hyperfractionated accelerated radiotherapy (HF-ACC-RT) was initiated. The primary endpoint was 1-year survival with local control (SLC). Methods and Materials: Patients with Stage III and IV (UICC) unresectable oro- and hypopharyngeal carcinomas were randomized for HF-ACC-RCT with 2 cycles of 5-FU (600 mg/m 2 /day)/carboplatinum (70 mg/m 2 ) on days 1-5 and 29-33 (arm A) or HF-ACC-RT alone (arm B). In both arms, there was a second randomization for testing the effect of prophylactically given G-CSF (263 μg, days 15-19) on mucosal toxicity. Total RT dose in both arms was 69.9 Gy in 38 days, with a concomitant boost regimen (weeks 1-3: 1.8 Gy/day, weeks 4 and 5: b.i.d. RT with 1.8 Gy/1.5 Gy). Between July 1995 and May 1999, 263 patients were randomized (median age 56 years; 96% Stage IV tumors, 4% Stage III tumors). Results: This analysis is based on 240 patients: 113 patients with RCT and 127 patients with RT, qualified for protocol and starting treatment. There were 178 oropharyngeal and 62 hypopharyngeal carcinomas. Treatment was tolerable in both arms, with a higher mucosal toxicity after RCT. Restaging showed comparable nonsignificant different CR + PR rates of 92.4% after RCT and 87.9% after RT (p=0.29). After a median observed time of 22.3 months, l- and 2-year local-regional control (LRC) rates were 69% and 51% after RCT and 58% and 45% after RT (p=0.14). There was a significantly better 1-year SLC after RCT (58%) compared with RT (44%, p=0.05). Patients with oropharyngeal carcinomas showed significantly better SLC after RCT (60%) vs. RT (40%, p=0.01); the smaller group of hypopharyngeal carcinomas had no statistical benefit of RCT (p=0.84). For both

  13. High energy particle accelerators as radiation Sources

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, M E [National Center for Nuclear Safety and Radiation Vontrol, Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    Small accelerators in the energy range of few million electron volts are usually used as radiation sources for various applications, like radiotherapy, food irradiation, radiation sterilization and in other industrial applications. High energy accelerators with energies reaching billions of electron volts also find wide field of applications as radiation sources. Synchrotrons with high energy range have unique features as radiation sources. This review presents a synopsis of cyclic accelerators with description of phase stability principle of high energy accelerators with emphasis on synchrotrons. Properties of synchrotron radiation are given together with their applications in basic and applied research. 13 figs.,1 tab.

  14. Hyperfractionated 3D conformal radiotherapy and concurrent chemotherapy for unresectable stage III non-small cell lung cancer

    International Nuclear Information System (INIS)

    Choi, E.K.; Ahn, S.D.; Yi, B.Y.; Chang, H.S.; Lee, J.H.; Suh, C.W.; Lee, J.S.; Kim, S.H.; Koh, Y.S.; Kim, W.S.; Kim, D.S.; Kim, W.D.; Sohn, K.H.

    1997-01-01

    Purpose/Objective: This phase II study has been conducted to determine the feasibility, toxicity, response rate, local control, distant metastasis, and survival of hyperfractionated 3D conformal radiotherapy and concurrent chemotherapy with mitomycin C, vinblastine, and cisplatin in unresectable stage III non-small cell lung cancer (NSCLC), and also to find the most ideal 3D conformal radiotherapy technique. Materials and Methods: From Aug 1993, 173 patients with unresectable stage III NSCLC were entered into this trial and 146 (84%) completed the treatment. Hyperfractionated radiotherapy was given to a total dose of 65-70 Gy (120 cGy/fx, bid) with concurrent 2 cycles of MVP chemotherapy (Mitomycin C 6 mg/m 2 d2 and d29, Vinblastine 6 mg/m 2 d2 and d29, Cisplatin 60 mg/m 2 d1 and d28). Of these 146 patients who completed the treatment, 78 received noncoplanar 3D conformal radiotherapy using 4-6 fields and 17 received coplanar segmented conformal radiotherapy. Clinical tumor response was assessed one month after the completion of radiotherapy by computerized tomography (CT) scan. Toxicity was graded by RTOG and SWOG criteria. Normal tissue complication probability (NTCP) for lung was calculated to find the correlation with radiation pneumonitis. Results: Nineteen (13%) had stage IIIa and 127 (87%) had IIIb disease including 16 with pleural effusion and 20 with supraclavicular lymph node metastases. Response rate was 74%, including 20% complete response and 54% partial response. With a minimum follow up of 12 months, overall survival was 60% at 1 year, 30% at 2 years and median survival was 15 months. Patients achieving a complete response (n=29) had a 2-year overall survival of 46.5% compared to 28.7% for partial responders (n=79) (p=.001). Actuarial local control was 66.7% at 1 year and 43.7% at 2 years. Actuarial distant free survival was 52.3% at 1 year and 39.8% at 2 years. Major hematologic toxicity (Gr 3-4) occurred in 33% of the patients but treatment delay

  15. Alterations of total non stimulated salivary flow in patients with squamous cell carcinoma of the mouth and oropharynx submitted to hyperfractionated radiation therapy; Alteracoes do fluxo salivar total nao estimulado em pacientes portadores de carcinoma espinocelular de boca e orofaringe submetidos a radioterapia por hiperfracionamento

    Energy Technology Data Exchange (ETDEWEB)

    Guebur, Maria Isabela [Faculdades Integradas Espirita, Curitiba, PR (Brazil)]. E-mail: isabelaguebur@aol.com; Rapoport, Abrao [Hospital Heliopolis (HOSPHEL), Sao Paulo, SP (Brazil). Curso de Pos-Graduacao em Ciencias da Saude; Sassi, Laurindo Moacir [Hospital Erasto Gaertner, Curitiba, PR (Brazil). Servico de Cirurgia e Traumatologia Buco-Maxico-Facial; Oliveira, Benedito Valdecir de; Ramos, Gyl Henrique Albrecht [Hospital Erasto Gaertner, Curitiba, PR (Brazil). Servico de Cirurgia de Cabeca e Pescoco; Pereira, Jose Carlos Gasparin [Hospital Erasto Gaertner, Curitiba, PR (Brazil). Servico de Radioterapia

    2004-07-01

    Prevention and early diagnosis are actually the most effective measures that we dispose to improve the prognostic of the malignant tumors. The mouth and oropharynx tumors are treated with success, when early diagnosed. The radiotherapy is almost always one of the selected treatments for these tumors. When cancer is diagnosed in advanced stages, many a time the treatment needs to be carried out swiftly to be efficient, and consequently the radio therapist use the hyperfractionated therapy, with the patient receiving two lower doses of radiation in two sessions daily, amounting to a higher daily dosage, of about 160 cGy/2x/day. When the major salivary glands are present in the radiated field, the xerostomia appears by the second week of treatment (1500 to 2000 cGy), changing the patient's health, and causing difficulties for him to eat, speak and sleep. The objective of this study was to evaluate the quantitative alterations of the total non stimulated salivate flow of patients who underwent hyperfractionated therapy for the treatment of squamous cell carcinoma of mouth and oropharynx. Samples of twelve male patients saliva from Erasto Gaertner Hospital in Curitiba, PR, Brazil, were examined. Two samples of saliva were collected from each patient, the first one before the beginning of the radiotherapy, and the second at the end of the treatment. As a result, we obtained salivary loss in 91.7% of the patients, with a percentage of total salivary flow loss of 62.9%, registered in the second collection. We concluded that the hyperfractionated therapy causes a marked xerostomia when the major salivary glands are in the radiated field. (author)

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

    International Nuclear Information System (INIS)

    Krstevska, V.; Smichkoska, S.

    2006-01-01

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

  17. Final Results of a Randomized Phase 2 Trial Investigating the Addition of Cetuximab to Induction Chemotherapy and Accelerated or Hyperfractionated Chemoradiation for Locoregionally Advanced Head and Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Seiwert, Tanguy Y., E-mail: tseiwert@medicine.bsd.uchicago.edu [Departments of Medicine, University of Chicago, Chicago, Illinois (United States); Melotek, James M. [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois (United States); Blair, Elizabeth A. [Department of Otolaryngology, University of Chicago, Chicago, Illinois (United States); Stenson, Kerstin M. [Department of Otolaryngology, Rush University, Chicago, Illinois (United States); Salama, Joseph K. [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Witt, Mary Ellyn [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois (United States); Brisson, Ryan J.; Chawla, Apoorva; Dekker, Allison [Departments of Medicine, University of Chicago, Chicago, Illinois (United States); Lingen, Mark W. [Department of Pathology, University of Chicago, Chicago, Illinois (United States); Kocherginsky, Masha [Department of Public Health Sciences, University of Chicago, Chicago, Illinois (United States); Villaflor, Victoria M. [Departments of Medicine, University of Chicago, Chicago, Illinois (United States); Cohen, Ezra E.W. [Moores Cancer Center, University of California, San Diego, San Diego, California (United States); Haraf, Daniel J. [Department of Radiation and Cellular Oncology, University of Chicago, Chicago, Illinois (United States); Vokes, Everett E. [Departments of Medicine, University of Chicago, Chicago, Illinois (United States)

    2016-09-01

    Purpose: The role of cetuximab in the treatment of locoregionally advanced head and neck squamous cell cancer (LA-HNSCC) remains poorly defined. In this phase 2 randomized study, we investigated the addition of cetuximab to both induction chemotherapy (IC) and hyperfractionated or accelerated chemoradiation. Methods and Materials: Patients with LA-HNSCC were randomized to receive 2 cycles of weekly IC (cetuximab, paclitaxel, carboplatin) and either Cetux-FHX (concurrent cetuximab, 5-fluorouracil, hydroxyurea, and 1.5 Gy twice-daily radiation therapy every other week to 75 Gy) or Cetux-PX (cetuximab, cisplatin, and accelerated radiation therapy with delayed concomitant boost to 72 Gy in 42 fractions). The primary endpoint was progression-free survival (PFS), with superiority compared with historical control achieved if either arm had 2-year PFS ≥70%. Results: 110 patients were randomly assigned to either Cetux-FHX (n=57) or Cetux-PX (n=53). The overall response rate to IC was 91%. Severe toxicity on IC was limited to rash (23% grade ≥3) and myelosuppression (38% grade ≥3 neutropenia). The 2-year rates of PFS for both Cetux-FHX (82.5%) and Cetux-PX (84.9%) were significantly higher than for historical control (P<.001). The 2-year overall survival (OS) was 91.2% for Cetux-FHX and 94.3% for Cetux-PX. With a median follow-up time of 72 months, there were no significant differences in PFS (P=.35) or OS (P=.15) between the treatment arms. The late outcomes for the entire cohort included 5-year PFS, OS, locoregional failure, and distant metastasis rates of 74.1%, 80.3%, 15.7%, and 7.4%, respectively. The 5-year PFS and OS were 84.4% and 91.3%, respectively, among human papillomavirus (HPV)-positive patients and 65.9% and 72.5%, respectively, among HPV-negative patients. Conclusions: The addition of cetuximab to IC and chemoradiation was tolerable and produced long-term control of LA-HNSCC, particularly among poor-prognosis HPV-negative patients. Further

  18. Final Results of a Randomized Phase 2 Trial Investigating the Addition of Cetuximab to Induction Chemotherapy and Accelerated or Hyperfractionated Chemoradiation for Locoregionally Advanced Head and Neck Cancer

    International Nuclear Information System (INIS)

    Seiwert, Tanguy Y.; Melotek, James M.; Blair, Elizabeth A.; Stenson, Kerstin M.; Salama, Joseph K.; Witt, Mary Ellyn; Brisson, Ryan J.; Chawla, Apoorva; Dekker, Allison; Lingen, Mark W.; Kocherginsky, Masha; Villaflor, Victoria M.; Cohen, Ezra E.W.; Haraf, Daniel J.; Vokes, Everett E.

    2016-01-01

    Purpose: The role of cetuximab in the treatment of locoregionally advanced head and neck squamous cell cancer (LA-HNSCC) remains poorly defined. In this phase 2 randomized study, we investigated the addition of cetuximab to both induction chemotherapy (IC) and hyperfractionated or accelerated chemoradiation. Methods and Materials: Patients with LA-HNSCC were randomized to receive 2 cycles of weekly IC (cetuximab, paclitaxel, carboplatin) and either Cetux-FHX (concurrent cetuximab, 5-fluorouracil, hydroxyurea, and 1.5 Gy twice-daily radiation therapy every other week to 75 Gy) or Cetux-PX (cetuximab, cisplatin, and accelerated radiation therapy with delayed concomitant boost to 72 Gy in 42 fractions). The primary endpoint was progression-free survival (PFS), with superiority compared with historical control achieved if either arm had 2-year PFS ≥70%. Results: 110 patients were randomly assigned to either Cetux-FHX (n=57) or Cetux-PX (n=53). The overall response rate to IC was 91%. Severe toxicity on IC was limited to rash (23% grade ≥3) and myelosuppression (38% grade ≥3 neutropenia). The 2-year rates of PFS for both Cetux-FHX (82.5%) and Cetux-PX (84.9%) were significantly higher than for historical control (P<.001). The 2-year overall survival (OS) was 91.2% for Cetux-FHX and 94.3% for Cetux-PX. With a median follow-up time of 72 months, there were no significant differences in PFS (P=.35) or OS (P=.15) between the treatment arms. The late outcomes for the entire cohort included 5-year PFS, OS, locoregional failure, and distant metastasis rates of 74.1%, 80.3%, 15.7%, and 7.4%, respectively. The 5-year PFS and OS were 84.4% and 91.3%, respectively, among human papillomavirus (HPV)-positive patients and 65.9% and 72.5%, respectively, among HPV-negative patients. Conclusions: The addition of cetuximab to IC and chemoradiation was tolerable and produced long-term control of LA-HNSCC, particularly among poor-prognosis HPV-negative patients. Further

  19. Concomitant Cisplatin and Hyperfractionated Radiotherapy in Locally Advanced Head and Neck Cancer: 10-Year Follow-Up of a Randomized Phase III Trial (SAKK 10/94)

    International Nuclear Information System (INIS)

    Ghadjar, Pirus; Simcock, Mathew; Studer, Gabriela; Allal, Abdelkarim S.; Ozsahin, Mahmut; Bernier, Jacques; Töpfer, Michael; Zimmermann, Frank; Betz, Michael; Glanzmann, Christoph; Aebersold, Daniel M.

    2012-01-01

    Purpose: To compare the long-term outcome of treatment with concomitant cisplatin and hyperfractionated radiotherapy versus treatment with hyperfractionated radiotherapy alone in patients with locally advanced head and neck cancer. Methods and Materials: From July 1994 to July 2000, a total of 224 patients with squamous cell carcinoma of the head and neck were randomized to receive either hyperfractionated radiotherapy alone (median total dose, 74.4 Gy; 1.2 Gy twice daily; 5 days per week) or the same radiotherapy combined with two cycles of cisplatin (20 mg/m 2 for 5 consecutive days during weeks 1 and 5). The primary endpoint was the time to any treatment failure; secondary endpoints were locoregional failure, metastatic failure, overall survival, and late toxicity assessed according to Radiation Therapy Oncology Group criteria. Results: Median follow-up was 9.5 years (range, 0.1–15.4 years). Median time to any treatment failure was not significantly different between treatment arms (hazard ratio [HR], 1.2 [95% confidence interval {CI}, 0.9–1.7; p = 0.17]). Rates of locoregional failure-free survival (HR, 1.5 [95% CI, 1.1–2.1; p = 0.02]), distant metastasis-free survival (HR, 1.6 [95% CI, 1.1–2.5; p = 0.02]), and cancer-specific survival (HR, 1.6 [95% CI, 1.0–2.5; p = 0.03]) were significantly improved in the combined-treatment arm, with no difference in major late toxicity between treatment arms. However, overall survival was not significantly different (HR, 1.3 [95% CI, 0.9–1.8; p = 0.11]). Conclusions: After long-term follow-up, combined-treatment with cisplatin and hyperfractionated radiotherapy maintained improved rates of locoregional control, distant metastasis-free survival, and cancer-specific survival compared to that of hyperfractionated radiotherapy alone, with no difference in major late toxicity.

  20. Serial histopathological changes in irradiated guinea pig lung receiving conventional fractionated and hyperfractionated irradiation

    International Nuclear Information System (INIS)

    Itoh, Satoshi; Inomata, Taisuke; Ogawa, Yasuhiro; Yoshida, Shoji; Sonobe, Hiroshi; Ohtsuki, Yuji

    1999-01-01

    The purpose of this study is to determine serial histopathological differences in guinea pig lungs receiving the same total dose as clinically used between conventional fractionated and hyperfractionated irradiation. The guinea pigs received 80 Gy in 40 daily fractions of 2 Gy each (conventional fractionation), 80 Gy in 80 fractions of 1 Gy each twice a day (hyperfractionation), 81 Gy in 27 daily fractions of 3 Gy each (conventional fractionation), or 81 Gy in 54 fractions of 1.5 Gy each twice a day (hyperfractionation). We evaluated the histopathological changes of irradiated guinea pig lungs at 1, 2, 3, 6, 9, and 12 months after irradiation. The guinea pig lungs that received 81 Gy in 27 daily fractions showed histopathological changes of inflammation including formation of lymph follicles after 6 months. The lungs which received 81 Gy in 54 fractions showed similar but slightly less pronounced changes than those that received 81 Gy in 27 daily fractions. The guinea pig lungs of other groups showed no histopathological changes during the observation period. In hyperfractionated irradiation the damage to the guinea pig lung is quantitatively less than that occurring as a result of conventional fractionated irradiation of the same total dose. (author)

  1. Serial histopathological changes in irradiated guinea pig lung receiving conventional fractionated and hyperfractionated irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Satoshi; Inomata, Taisuke; Ogawa, Yasuhiro; Yoshida, Shoji; Sonobe, Hiroshi; Ohtsuki, Yuji [Kochi Medical School, Nankoku (Japan)

    1999-05-01

    The purpose of this study is to determine serial histopathological differences in guinea pig lungs receiving the same total dose as clinically used between conventional fractionated and hyperfractionated irradiation. The guinea pigs received 80 Gy in 40 daily fractions of 2 Gy each (conventional fractionation), 80 Gy in 80 fractions of 1 Gy each twice a day (hyperfractionation), 81 Gy in 27 daily fractions of 3 Gy each (conventional fractionation), or 81 Gy in 54 fractions of 1.5 Gy each twice a day (hyperfractionation). We evaluated the histopathological changes of irradiated guinea pig lungs at 1, 2, 3, 6, 9, and 12 months after irradiation. The guinea pig lungs that received 81 Gy in 27 daily fractions showed histopathological changes of inflammation including formation of lymph follicles after 6 months. The lungs which received 81 Gy in 54 fractions showed similar but slightly less pronounced changes than those that received 81 Gy in 27 daily fractions. The guinea pig lungs of other groups showed no histopathological changes during the observation period. In hyperfractionated irradiation the damage to the guinea pig lung is quantitatively less than that occurring as a result of conventional fractionated irradiation of the same total dose. (author)

  2. Induction Chemotherapy and Continuous Hyperfractionated Accelerated Radiotherapy (CHART) for Patients With Locally Advanced Inoperable Non-Small-Cell Lung Cancer: The MRC INCH Randomized Trial

    International Nuclear Information System (INIS)

    Hatton, Matthew; Nankivell, Matthew; Lyn, Ethan; Falk, Stephen; Pugh, Cheryl; Navani, Neal; Stephens, Richard; Parmar, Mahesh

    2011-01-01

    Purpose: Recent clinical trials and meta-analyses have shown that both CHART (continuous hyperfractionated accelerated radiation therapy) and induction chemotherapy offer a survival advantage over conventional radical radiotherapy for patients with inoperable non-small cell-lung cancer (NSCLC). This multicenter randomized controlled trial (INCH) was set up to assess the value of giving induction chemotherapy before CHART. Methods and Materials: Patients with histologically confirmed, inoperable, Stage I-III NSCLC were randomized to induction chemotherapy (ICT) (three cycles of cisplatin-based chemotherapy followed by CHART) or CHART alone. Results: Forty-six patients were randomized (23 in each treatment arm) from 9 UK centers. As a result of poor accrual, the trial was closed in December 2007. Twenty-eight patients were male, 28 had squamous cell histology, 34 were Stage IIIA or IIIB, and all baseline characteristics were well balanced between the two treatment arms. Seventeen (74%) of the 23 ICT patients completed the three cycles of chemotherapy. All 42 (22 CHART + 20 ICT) patients who received CHART completed the prescribed treatment. Median survival was 17 months in the CHART arm and 25 months in the ICT arm (hazard ratio of 0.60 [95% CI 0.31-1.16], p = 0.127). Grade 3 or 4 adverse events (mainly fatigue, dysphagia, breathlessness, and anorexia) were reported for 13 (57%) CHART and 13 (65%) ICT patients. Conclusions: This small randomized trial indicates that ICT followed by CHART is feasible and well tolerated. Despite closing early because of poor accrual, and so failing to show clear evidence of a survival benefit for the additional chemotherapy, the results suggest that CHART, and ICT before CHART, remain important options for the treatment of inoperable NSCLC and deserve further study.

  3. Preoperative hyperfractionated radiotherapy with concurrent chemotherapy in resectable esophageal cancer

    International Nuclear Information System (INIS)

    Kim, Jong H.; Choi, Eun K.; Kim, Sung B.; Park, Seung I.; Kim, Dong K.; Song, Ho Y.; Jung, Hwoon Y.; Min, Young I.

    2001-01-01

    Purpose: To evaluate the local control rates, survival rates, and patterns of failure for esophageal cancer patients receiving preoperative concurrent chemotherapy and hyperfractionated radiotherapy followed by esophagectomy. Methods and Materials: From May 1993 through January 1997, 94 patients with resectable esophageal cancers received continuous hyperfractionated radiation (4,800 cGy/40 fx/4 weeks), with concurrent FP chemotherapy (5-FU 1 g/m 2 /day, days 2-6, 30-34, CDDP 60 mg/m 2 /day, days 1, 29) followed by esophagectomy 3-4 weeks later. If there was evidence of disease progression on preoperative re-evaluation work-up, or if the patient refused surgery, definitive chemoradiotherapy was delivered. Minimum follow-up time was 2 years. Results: All patients successfully completed preoperative treatment and were then followed until death. Fifty-three patients received surgical resection, and another 30 were treated with definitive chemoradiotherapy. Eleven patients did not receive further treatment. Among 91 patients who received clinical reevaluation, we observed 35 having clinical complete response (CR) (38.5%). Pathologic CR rate was 49% (26 patients). Overall survival rate was 59.8% at 2 years and 40.3% at 5 years. Median survival time was 32 months. In 83 patients who were treated with surgery or definitive chemoradiotherapy, the esophagectomy group showed significantly higher survival, disease-free survival, and local disease-free survival rates than those in the definitive chemoradiation group. Conclusion: Preoperative chemoradiotherapy in this trial showed improved clinical and pathologic tumor response and survival when compared to historical results. Patients who underwent esophagectomy following chemoradiation showed decreased local recurrence and improved survival and disease-free survival rates compared to the definitive chemoradiation group

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  5. Radiation safety aspects of high energy particle accelerators

    International Nuclear Information System (INIS)

    Subbaiah, K.V.

    2007-01-01

    High-energy accelerators are widely used for various applications in industry, medicine and research. These accelerators are capable of accelerating both ions and electrons over a wide range of energy and subsequently are made to impinge on the target materials. Apart from generating intended reactions in the target, these projectiles can also generate highly penetrating radiations such as gamma rays and neutrons. Over exposure to these radiations will cause deleterious effects on the living beings. Various steps taken to protect workers and general public from these harmful radiations is called radiation safety. The primary objective in establishing permissible values for occupational workers is to keep the radiation worker well below a level at which adverse effects are likely to be observed during one's life time. Another objective is to minimize the incidence of genetic effects for the population as a whole. Today's presentation on radiation safety of accelerators will touch up on the following sub-topics: Types of particle accelerators and their applications; AERB directives on dose limits; Radiation Source term of accelerators; Shielding Design-Use of Transmission curves and Tenth Value layers; Challenges for accelerator health physicists

  6. A Phase I Study of Chemoradiotherapy With Use of Involved-Field Conformal Radiotherapy and Accelerated Hyperfractionation for Stage III Non-Small Cell Lung Cancer: WJTOG 3305

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Takuhito, E-mail: tada@msic.med.osaka-cu.ac.jp [Department of Radiology, Osaka City University Graduate School of Medicine, Osaka (Japan); Department of Radiology, Izumi Municipal Hospital, Izumi (Japan); Chiba, Yasutaka [Department of Environmental Medicine and Behavioural Science, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Tsujino, Kayoko [Department of Radiation Oncology, Hyogo Cancer Center, Akashi (Japan); Fukuda, Haruyuki [Department of Radiology, Osaka Prefectural Medical Center for Respiratory and Allergic Diseases, Habikino (Japan); Nishimura, Yasumasa [Department of Radiation Oncology, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Kokubo, Masaki [Division of Radiation Oncology, Institute of Biomedical Research and Innovation, Kobe (Japan); Negoro, Shunichi [Department of Medical Oncology, Hyogo Cancer Center, Akashi (Japan); Kudoh, Shinzoh [Department of Respiratory Medicine, Osaka City University Graduate School of Medicine, Osaka (Japan); Fukuoka, Masahiro [Department of Medical Oncology, Izumi Municipal Hospital, Izumi (Japan); Nakagawa, Kazuhiko [Department of Medical Oncology, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Nakanishi, Yoichi [Research Institute for Disease of the Chest, Graduate School of Medical Science, Kyusyu University, Fukuoka (Japan)

    2012-05-01

    Purpose: A Phase I study to determine a recommended dose of thoracic radiotherapy using accelerated hyperfractionation for unresectable non-small-cell lung cancer was conducted. Methods and Materials: Patients with unresectable Stage III non-small-cell lung cancer were treated intravenously with carboplatin (area under the concentration curve 2) and paclitaxel (40 mg/m{sup 2}) on Days 1, 8, 15, and 22 with concurrent twice-daily thoracic radiotherapy (1.5 Gy per fraction) beginning on Day 1 followed by two cycles of consolidation chemotherapy using carboplatin (area under the concentration curve 5) and paclitaxel (200 mg/m{sup 2}). Total doses were 54 Gy in 36 fractions, 60 Gy in 40 fractions, 66 Gy in 44 fractions, and 72 Gy in 48 fractions at Levels 1 to 4. The dose-limiting toxicity, defined as Grade {>=}4 esophagitis and neutropenic fever and Grade {>=}3 other nonhematologic toxicities, was monitored for 90 days. Results: Of 26 patients enrolled, 22 patients were assessable for response and toxicity. When 4 patients entered Level 4, enrollment was closed to avoid severe late toxicities. Dose-limiting toxicities occurred in 3 patients. They were Grade 3 neuropathy at Level 1 and Level 3 and Grade 3 infection at Level 1. However, the maximum tolerated dose was not reached. The median survival time was 28.6 months for all patients. Conclusions: The maximum tolerated dose was not reached, although the dose of radiation was escalated to 72 Gy in 48 fractions. However, a dose of 66 Gy in 44 fractions was adopted for this study because late toxicity data were insufficient.

  7. A Phase I Study of Chemoradiotherapy With Use of Involved-Field Conformal Radiotherapy and Accelerated Hyperfractionation for Stage III Non-Small Cell Lung Cancer: WJTOG 3305

    International Nuclear Information System (INIS)

    Tada, Takuhito; Chiba, Yasutaka; Tsujino, Kayoko; Fukuda, Haruyuki; Nishimura, Yasumasa; Kokubo, Masaki; Negoro, Shunichi; Kudoh, Shinzoh; Fukuoka, Masahiro; Nakagawa, Kazuhiko; Nakanishi, Yoichi

    2012-01-01

    Purpose: A Phase I study to determine a recommended dose of thoracic radiotherapy using accelerated hyperfractionation for unresectable non–small-cell lung cancer was conducted. Methods and Materials: Patients with unresectable Stage III non–small-cell lung cancer were treated intravenously with carboplatin (area under the concentration curve 2) and paclitaxel (40 mg/m 2 ) on Days 1, 8, 15, and 22 with concurrent twice-daily thoracic radiotherapy (1.5 Gy per fraction) beginning on Day 1 followed by two cycles of consolidation chemotherapy using carboplatin (area under the concentration curve 5) and paclitaxel (200 mg/m 2 ). Total doses were 54 Gy in 36 fractions, 60 Gy in 40 fractions, 66 Gy in 44 fractions, and 72 Gy in 48 fractions at Levels 1 to 4. The dose-limiting toxicity, defined as Grade ≥4 esophagitis and neutropenic fever and Grade ≥3 other nonhematologic toxicities, was monitored for 90 days. Results: Of 26 patients enrolled, 22 patients were assessable for response and toxicity. When 4 patients entered Level 4, enrollment was closed to avoid severe late toxicities. Dose-limiting toxicities occurred in 3 patients. They were Grade 3 neuropathy at Level 1 and Level 3 and Grade 3 infection at Level 1. However, the maximum tolerated dose was not reached. The median survival time was 28.6 months for all patients. Conclusions: The maximum tolerated dose was not reached, although the dose of radiation was escalated to 72 Gy in 48 fractions. However, a dose of 66 Gy in 44 fractions was adopted for this study because late toxicity data were insufficient.

  8. Accelerators for the advanced radiation technology project

    International Nuclear Information System (INIS)

    Maruyama, Michio

    1990-01-01

    Ion beam irradiation facilities are now under construction for the advanced radiation technology (ART) project in Takasaki Radiation Chemistry Research Establishment of (Japan Atomic Energy Research Institute) JAERI. The project is intended to make an effective use of ion beams, especially ion beams, in the research field of radiation application technology. The TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) facilities include four ion accelerators to produce almost all kinds of energetic ions in the periodic table. The facilities are also provided with several advanced irradiation means and act as very powerful accelerator complex for material development. Specifically, this report presents an outline of the ART project, features of TIARA as accelerator facilities dedicated to material development, the AVF cyclotron under construction (Sumitomo Heavy Industries, Ltd., Model 930), tandem accelerator, microbeam, and experimental instruments used. (N.K.)

  9. Phase I dose escalating trial of hyperfractionated pre-operative chemoradiation for locally advanced rectal cancer

    International Nuclear Information System (INIS)

    Movsas, Benjamin; Hanlon, Alexandra L.; Lanciano, Rachelle; Scher, Richard M.; Weiner, Louis M.; Sigurdson, Elin R.; Hoffman, John P.; Eisenberg, Burton L.; Cooper, Harry S.; Provins, Susan; Coia, Lawrence R.

    1998-01-01

    Purpose: To determine the acute toxicity, post-operative complications, pathologic response and extent of downstaging to high dose pre-operative radiation using a hyperfractionated radiation boost and concurrent chemotherapy in a prospective Phase I trial. Materials and Methods: To be eligible for this study, patients had to have adenocarcinoma of the rectum less than 12 cm from the anal verge with either Stage T4 or T3 but greater than 4 cm or greater than 40% of the bowel circumference. All patients received 45 Gy pelvic radiation (1.8 Gy per fraction). Subsequent radiation was given to the region of the gross tumor with a 2 cm margin. This 'boost' treatment was given at 1.2 Gy twice daily to a total dose of 54.6 Gy for Level I, 57 Gy for Level II, and 61.8 Gy for Level III. 5-FU was given at 1g/m 2 over 24 hours for a four day infusion during the first and sixth weeks of radiation, with the second course concurrent with the hyperfractionated radiation. Surgical resection was carried out 4-6 weeks following completion of chemoradiation (in curative cases) and additional adjuvant chemotherapy consisting of 5-FU and Leucovorin was given for an additional 4 monthly cycles Days 1 through 5 beginning four weeks post surgery. Results: Twenty-seven patients, age 40-82 (median 61), completed the initial course of chemoradiation and are included in the analysis of toxicity. The median follow-up is 27 months (range 8-68). Eleven patients were treated to a dose of 54.6 Gy, nine patients to 57 Gy, and seven patients to 61.8 Gy. Twenty-one patients had T3 tumors, and six patients T4 tumors. Grade III acute toxicity from chemoradiation included proctitis (5 patients), dermatitis (9), diarrhea (five), leukopenia (1), cardiac (1). Grade IV toxicities included one patient with diarrhea (on dose Level I) and one patient (on dose Level III) with cardiac toxicity (unrelated to radiation). Surgical resection consisted of abdominal perineal resection in 16 and low anterior resection

  10. Malignant astrocytoma: hyperfractionated and standard radiotherapy with chemotherapy in a randomized prospective clinical trial

    International Nuclear Information System (INIS)

    Payne, D.G.; Simpson, W.J.; Keen, C.; Platts, M.E.

    1982-01-01

    A prospective randomized trial of 157 patients with malignant astrocytomas (Grade III or IV) was carried out at a single institution. The minimization technique ensured balanced distribution of prognostic factors between the treatment groups. All received oral lomustine (CCNU, 80 mg/m 2 ) six weekly and hydroxyurea (HU, 3.5 gm/m 2 over 5 days) three weekly, for one year or until recurrence, with doses adjusted for myelosuppression. Patients were randomized to daily (5000 rad in 25 fractions (fr) in 5 weeks) or Q3h (every 3 hours) Cobalt 60 irradiation (3600-4000 rad in 36-40 fr of 100 rad each, given 4 fr per day at 3-hour intervals over two weeks). Steroid therapy (up to 16 mg day dexamethasone) was permitted. Complications were moderate and equivalent in the two groups. No significant survival or toxicity differences were seen between the two groups. Age, initial performance status, and extent of surgical resection were found to be significant (P<0.01) prognostic factors for survival. Median survival of the whole group was 48 weeks with a minimum follow-up of one year. There was no advantage to large radiation fields. The hyperfractionation and daily regimes had similar efficacy and toxicity. Hyperfractionation with chemotherapy offers a useful alternative approach in the management of this disease

  11. Phase I Trial of Gross Total Resection, Permanent Iodine-125 Brachytherapy, and Hyperfractionated Radiotherapy for Newly Diagnosed Glioblastoma Multiforme

    International Nuclear Information System (INIS)

    Chen, Allen M.; Chang, Susan; Pouliot, Jean; Sneed, Penny K.; Prados, Michael D.; Lamborn, Kathleen R.; Malec, Mary K.; McDermott, Michael W.; Berger, Mitchell S.; Larson, David A.

    2007-01-01

    Purpose: To evaluate the feasibility of gross total resection and permanent I-125 brachytherapy followed by hyperfractionated radiotherapy for patients with newly diagnosed glioblastoma. Methods and Materials: From April 1999 to May 2002, 21 patients with glioblastoma multiforme were enrolled on a Phase I protocol investigating planned gross total resection and immediate placement of permanent I-125 seeds, followed by postoperative hyperfractionated radiotherapy to a dose of 60 Gy at 100 cGy b.i.d., 5 days per week. Median age and Karnofsky performance status were 50 years (range, 32-65 years) and 90 (range, 70-100), respectively. Toxicity was assessed according to Radiation Therapy Oncology Group criteria. Results: Eighteen patients completed treatment according to protocol. The median preoperative tumor volume on magnetic resonance imaging was 18.6 cm 3 (range, 4.4-41.2 cm 3 ). The median brachytherapy dose measured 5 mm radially outward from the resection cavity was 400 Gy (range, 200-600 Gy). Ten patients underwent 12 reoperations, with 11 of 12 reoperations demonstrating necrosis without evidence of tumor. Because of high toxicity, the study was terminated early. Median progression-free survival and overall survival were 57 and 114 weeks, respectively, but not significantly improved compared with historical patients treated at University of California, San Francisco, with gross total resection and radiotherapy without brachytherapy. Conclusions: Treatment with gross total resection and permanent I-125 brachytherapy followed by hyperfractionated radiotherapy as performed in this study results in high toxicity and reoperation rates, without demonstrated improvement in survival

  12. Betatron radiation from a laser-plasma accelerator

    International Nuclear Information System (INIS)

    Schnell, Michael

    2014-01-01

    The presented thesis investigates the processes which lead to the generation of highenergetic X-ray radiation, also known as ''betatron radiation'', by means of a relativistic laser-plasma interaction. The generated betatron radiation has been extensively characterized by measuring its radiated intensity, energy distribution, far-field beam profile, and source size. It was shown for the first time that betatron radiation can be used as a non-invasive diagnostic tool to retrieve very subtle information on the electron acceleration dynamics within the plasma wave. Furthermore, a compact polarimeter setup has been developed in a unique experiment in which the polarization state of the laser-plasma generated betatron radiation was measured in single-shot mode. This lead to a detailed study of the orientation of the electron trajectory within the plasma interaction. By controlling the injection of the electrons into the plasma wave it was demonstrated that one can tune the polarization state of the emitted X-rays. This result is very promising for further applications, particularly for feeding the electrons into an additional conventional accelerator or a permanent magnet based undulator for the production of intense X-ray beams. During this work, the experimental setup for accelerating electrons and generating high-energy X-ray beams was consistently improved: to enhance both its reliability and stability. Subsequently, the betatron radiation was used as a reliable diagnostic tool of the electron dynamics within the plasma. Parallel to the experimental work, 3-Dimensional Particle-In-Cell (3D-PlC) simulations were performed together with colleagues from the University of Duesseldorf. The simulations included the electron acceleration and the X-ray generation processes together with the recoil force acting on an accelerating electron caused by the emitted radiation during which one can also ascertain its polarization state. The simulations proved to be in good agreement

  13. Treatment of Children With Central Nervous System Primitive Neuroectodermal Tumors/Pinealoblastomas in the Prospective Multicentric Trial HIT 2000 Using Hyperfractionated Radiation Therapy Followed by Maintenance Chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Nicolas U., E-mail: nicolas.gerber@kispi.uzh.ch [Department of Pediatric Oncology, University Children' s Hospital, Zurich (Switzerland); Hoff, Katja von; Resch, Anika [Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Ottensmeier, Holger [Department of Pediatric Oncology, University of Wuerzburg, Wuerzburg (Germany); Kwiecien, Robert; Faldum, Andreas [Institute of Biostatistics and Clinical Research, University of Muenster (Germany); Matuschek, Christiane [Department of Radiation Oncology, Medical Faculty, Heinrich Heine University of Duesseldorf, Duesseldorf (Germany); Hornung, Dagmar [Department of Radiotherapy and Radio-Oncology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Bremer, Michael [Institute for Radiation Therapy and Special Oncology, Hannover Medical School, Hannover (Germany); Benesch, Martin [Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz (Austria); Pietsch, Torsten [Department of Neuropathology, University of Bonn, Bonn (Germany); Warmuth-Metz, Monika [Department of Neuroradiology, University of Wuerzburg, Wuerzburg (Germany); Kuehl, Joachim [Department of Pediatric Oncology, University of Wuerzburg, Wuerzburg (Germany); Rutkowski, Stefan [Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Kortmann, Rolf D. [Department of Radiation Oncology, University of Leipzig, Leipzig (Germany)

    2014-07-15

    Purpose: The prognosis for children with central nervous system primitive neuroectodermal tumor (CNS-PNET) or pinealoblastoma is still unsatisfactory. Here we report the results of patients between 4 and 21 years of age with nonmetastatic CNS-PNET or pinealoblastoma diagnosed from January 2001 to December 2005 and treated in the prospective GPOH-trial P-HIT 2000-AB4. Methods and Materials: After surgery, children received hyperfractionated radiation therapy (36 Gy to the craniospinal axis, 68 Gy to the tumor region, and 72 Gy to any residual tumor, fractionated at 2 × 1 Gy per day 5 days per week) accompanied by weekly intravenous administration of vincristine and followed by 8 cycles of maintenance chemotherapy (lomustine, cisplatin, and vincristine). Results: Twenty-six patients (15 with CNS-PNET; 11 with pinealoblastoma) were included. Median age at diagnosis was 11.5 years old (range, 4.0-20.7 years). Gross total tumor resection was achieved in 6 and partial resection in 16 patients (indistinct, 4 patients). Median follow-up of the 15 surviving patients was 7.0 years (range, 5.2-10.0 years). The combined response rate to postoperative therapy was 17 of 20 (85%). Eleven of 26 patients (42%; 7 of 15 with CNS-PNET; 4 of 11 with pinealoblastoma) showed tumor progression or relapse at a median time of 1.3 years (range, 0.5-1.9 years). Five-year progression-free and overall survival rates (±standard error [SE]) were each 58% (±10%) for the entire cohort: CNS-PNET was 53% (±13); pinealoblastoma was 64% (±15%; P=.524 and P=.627, respectively). Conclusions: Postoperative hyperfractionated radiation therapy with local dose escalation followed by maintenance chemotherapy was feasible without major acute toxicity. Survival rates are comparable to those of a few other recent studies but superior to those of most other series, including the previous trial, HIT 1991.

  14. Hyperfractionated Radiotherapy with Concomitant Boost Technique for Unresectable Non-Small Cell Carcinoma of the Lung

    International Nuclear Information System (INIS)

    Chun, Ha Chung; Lee, Myung Za

    1991-01-01

    Twenty five patients with unresectable non-small cell carcinoma of the lung have been treated with hyperfractionated radiotherapy with concomitant boost technique since September, 1989. Those patients with history of previous surgery or chemotherapy, pleural effusion or significant weight loss (greater than 10% of body weight) were excluded from the study. Initially, 27 Gy were delivered in 15 fractions in 3 weeks to the large field. Thereafter, large field received 1.8 Gy and cone down boost field received 1.4Gy with twice a day fractinations up to 49.4Gy. After 49.4Gy, only boost field was treated twice a day with 1.8 and 1.4 Gy. Total tumor doses were 62.2Gy for 12 patients and 65.4Gy for remaining 13 patients. Follow up period was ranged from 6 to 24 month. Actuarial survival rates at 6, 12, and 18 month were 88%, 62%, and 38%, respectively. Corresponding disease free survival rates were 88%, 41%, and 21%, respectively. Actuarial cumulative local failure rates at 9,12 and 15 month were 36%, 42%, and 59%, respectively. No significant increase of acute or late complications including radiation pneumonitis was noted with maximum follow up of 24 month. Although the longer follow up is needed, it is worthwhile to try the prospective randomized study to evaluate the efficacy of hyperfractionated radiotherapy with concomitant boost technique for unresectable non-small cell lung cancers in view of excellent tolerance of this treatment. In the future, further increase of total radiation dose might be necessary to improve local control for non-small cell lung cancer

  15. Special radiation protection aspects of medical accelerators

    CERN Document Server

    Silari, Marco

    2001-01-01

    Radiation protection aspects relevant to medical accelerators are discussed. An overview is first given of general safety requirements. Next. shielding and labyrinth design are discussed in some detail for the various types of accelerators, devoting more attention to hadron machines as they are far less conventional than electron linear accelerators. Some specific aspects related to patient protection are also addressed. Finally, induced radioactivity in accelerator components and shielding walls is briefly discussed. Three classes of machines are considered: (1) medical electron linacs for 'conventional' radiation therapy. (2) low energy cyclotrons for production of radionuclides mainly for medical diagnostics and (3) medium energy cyclotrons and synchrotrons for advanced radiation therapy with protons or light ion beams (hadron therapy). (51 refs).

  16. Final report of a randomized trial on altered-fractionated radiotherapy in nasopharyngeal carcinoma prematurely terminated by significant increase in neurologic complications

    International Nuclear Information System (INIS)

    Teo, Peter Man Lung; Leung, Sing Fai; Chan, Anthony Tak Cheung; Leung, Thomas Wai Tong; Choi, Peter Ho Keung; Kwan, Wing Hong; Lee, Wai Yee; Chau, Ricky Ming Chun; Yu, Peter Kau Wing; Johnson, Philip James

    2000-01-01

    Purpose: The aim of the present study was to compare the survival, local control and complications of conventional/accelerated-hyperfractionated radiotherapy and conventional radiotherapy in nonmetastatic nasopharyngeal carcinoma (NPC). Methods and Materials: From February 1993 to October 1995, 159 patients with newly diagnosed nonmetastatic (M0) NPC with N0 or 4 cm or less N1 disease (Ho's N-stage classification, 1978) were randomized to receive either conventional radiotherapy (Arm I, n = 82) or conventional/accelerated-hyperfractionated radiotherapy (Arm II, n = 77). Stratification was according to the T stage. The biologic effective dose (10 Grays) to the primary and the upper cervical lymphatics were 75.0 and 73.1 for Arm I and 84.4 and 77.2 for Arm II, respectively. Results: With comparable distribution among the T stages between the two arms, the free from local failure rate at 5 years after radiotherapy was not significantly different between the two arms (85.3%; 95% confidence interval, 77.2-93.4% for Arm I; and 88.9%; 95% confidence interval, 81.7-96.2% for Arm II). The two arms were also comparable in overall survival, relapse-free survival, and rates of distant metastasis and regional relapse. Conventional/accelerated-hyperfractionated radiotherapy was associated with significantly increased radiation-induced damage to the central nervous system (including temporal lobe, cranial nerves, optic nerve/chiasma, and brainstem/spinal cord) in Arm II. Although insignificant, radiation-induced cranial nerve(s) palsy (typically involving VIII-XII), trismus, neck soft tissue fibrosis, and hypopituiturism and hypothyroidism occurred more often in Arm II. In addition, the complications occurred at significantly shorter intervals after radiotherapy in Arm II. Conclusion: Accelerated hyperfractionation when used in conjunction with a two-dimensional radiotherapy planning technique, in this case the Ho's technique, resulted in increased radiation damage to the central

  17. Radiation protection in large linear accelerators

    International Nuclear Information System (INIS)

    Oliva, Jose de Jesus Rivero

    2013-01-01

    The electron linear accelerators can be used in industrial applications that require powerful sources of ionizing radiation. They have the important characteristic of not representing a radiation hazard when the accelerators remain electrically disconnected. With the plant in operation, a high reliability defense in depth reduces the risk of radiological accidents to extremely small levels. It is practically impossible that a person could enter into the radiation bunker with the accelerators connected. Aceletron Irradiacao Industrial, located in Rio de Janeiro, offers services of irradiation by means of two powerful electron linear accelerators, with 15 kW power and 10 MeV electron energy. Despite the high level of existing radiation safety, a simplified risk study is underway to identify possible sequences of radiological accidents. The study is based on the combined application of the event and fault trees techniques. Preliminary results confirm that there is a very small risk of entering into the irradiation bunker with the accelerators in operation, but the risk of an operator entering into the bunker during a process interruption and remaining there without notice after the accelerators were restarted may be considerably larger. Based on these results the Company is considering alternatives to reduce the likelihood of human error of this type that could lead to a radiological accident. The paper describes the defense in depth of the irradiation process in Aceletron Irradiacao Industrial, as well as the models and preliminary results of the ongoing risk analysis, including the additional safety measures which are being evaluated. (author)

  18. Rapidly alternating combination of cisplatin-based chemotherapy and hyperfractionated accelerated radiotherapy in split course for Stage IIIA and Stage IIIB non-small cell lung cancer: results of a Phase I-II study by the GOTHA group

    Energy Technology Data Exchange (ETDEWEB)

    Alberto, P.; Mermillod, B. [Hopital Cantonal Geneve, Geneva (Switzerland); Mirimanoff, R.O.; Leyvraz, S.; Nagy-Mignotte, H.; Bolla, M.; Wellmann, D.; Moro, D.; Brambilla, E. [Hopital Cantonal Universitaire, Lausanne (Switzerland)

    1995-08-01

    The prognosis of stage III non-small cell lung cancer (NSCLC) can be improved by a combination of radiotherapy (RT) and chemotherapy (CT). In this study, the GOTHA group evaluated the feasibility, tolerance, tumour response, pattern of failure and effect on survival of a combination alternating accelerated hyperfractionated (AH) RT and CT in patients with tumour stage III NSCLC. Toxic effects were leucopenia, nausea and vomiting, mucositis, diarrhoea, alopecia and peripheral neuropathy. Alternating CT and AHRT, as used in this study, were well tolerated and allowed full dose delivery within less than 12 weeks. Initial response was not predictive of survival. The survival curve is encouraging and the 5 year survival is superior to the 5% generally observed with conventionally fractionated radiotherapy. (author).

  19. Radiation environment of proton accelerators and storage rings

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, G R

    1976-03-08

    These lecture notes survey the physical processes that give rise to the stray-radiation environment of proton synchrotrons and storage rings, with emphasis on their importance for radiation protection. The origins of the prompt radiation field (which disappears when the accelerator is switched off) are described in some detail: proton-nucleus interactions, extranuclear cascades, muon generation and transport. The effects of induced radioactivity in the accelerator structure and surroundings, notably in iron, concrete, air, and water, are discussed, and methods for monitoring hadrons in the radiation environment outside the accelerator are listed. Seventy-six references to the literature are included.

  20. Prospective randomized comparison of single-dose versus hyperfractionated total-body irradiation in patients with hematologic malignancies

    International Nuclear Information System (INIS)

    Girinsky, T.; Benhamou, E.; Bourhis, J.H.; Dhermain, F.; Guillot-Valls, D.; Ganansia, V.; Luboinski, M.; Perez, A.; Cosset, J.M.; Socie, G.; Baume, D.; Bouaouina, N.; Briot, E.; Baudre, A.; Bridier, A.; Pico, J.L.

    2001-01-01

    The efficiency of the two irradiation modes are similar, but the hyperfractionated irradiation seems superior in term of global and specific survival. The incidence rates of pneumopathies are not different between the two groups but the incidence rate of the liver vein-occlusive illness is superior in the group treated by non fractionated whole body irradiation. The cost of the hyperfractionated whole body irradiation is superior to this one of the non fractionated whole body irradiation around a thousand dollars. (N.C.)

  1. Solving radiation problems at particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Nikolai V. Mokhov

    2001-12-11

    At high-intensity high-energy particle accelerators, consequences of a beam-induced radiation impact on machine and detector components, people, environment and complex performance can range from negligible to severe. The specifics, general approach and tools used at such machines for radiation analysis are described. In particular, the world leader Fermilab accelerator complex is considered, with its fixed target and collider experiments, as well as new challenging projects such as LHC, VLHC, muon collider and neutrino factory. The emphasis is on mitigation of deleterious beam-induced radiation effects and on the key role of effective computer simulations.

  2. Solving radiation problems at particle accelerators

    International Nuclear Information System (INIS)

    Mokhov, N.V.

    2001-01-01

    At high-intensity high-energy particle accelerators, consequences of a beam-induced radiation impact on machine and detector components, people, environment and complex performance can range from negligible to severe. The specifics, general approach and tools used at such machines for radiation analysis are described. In particular, the world leader Fermilab accelerator complex is considered, with its fixed target and collider experiments, as well as new challenging projects such as LHC, VLHC, muon collider and neutrino factory. The emphasis is on mitigation of deleterious beam-induced radiation effects and on the key role of effective computer simulations

  3. Radiation safety of Takasaki ion accelerators for advanced radiation in JAERI

    International Nuclear Information System (INIS)

    Watanabe, Hiromasa; Tanaka, Susumu; Anazawa, Yutaka

    1991-01-01

    Building layout of Takasaki ion accelerator facility has been started since 1987, with the propulsion of research development of (1) cosmetic environment materials, (2) nuclear fusion reactors, (3) biotechnology, and (4) new functional materials. This paper deals with an AVF cyclotron and a tandem type accelerator, focusing on safety design, radiation safety management, and radioactive waste management. Safety design is discussed in view of radiation shielding and activation countermeasures. Radiation safety management covers radiation monitoring in the workplace, exhaust radioactivity, environment outside the facility, and the other equipments; personal monitoring; and protective management of exposure. For radiation waste management, basic concept and management methods are commented on. (N.K.)

  4. X radiation sources based on accelerators

    International Nuclear Information System (INIS)

    Couprie, M.E.; Filhol, J.M.

    2008-01-01

    Light sources based on accelerators aim at producing very high brilliance coherent radiation, tunable from the infrared to X-ray range, with picosecond or femtosecond light pulses. The first synchrotron light sources were built around storage rings in which a large number of relativistic electrons produce 'synchrotron radiation' when their trajectory is subjected to a magnetic field, either in bending magnets or in specific insertion devices (undulators), made of an alternating series of magnets, allowing the number of curvatures to be increased and the radiation to be reinforced. These 'synchrotron radiation' storage rings are now used worldwide (there are more than thirty), and they simultaneously distribute their radiation to several tens of users around the storage ring. The most effective installations in term of brilliance are the so-called third generation synchrotron radiation light sources. The radiation produced presents pulse durations of the order of a few tens of ps, at a high rate (of the order of MHz); it is tunable over a large range, depending on the magnetic field and the electron beam energy and its polarisation is adjustable (in the V-UV-soft-X range). Generally, a very precise spectral selection is made by the users with a monochromator. The single pass linear accelerators can produce very short electron bunches (around 100 fs). The beam of very high electronic density is sent into successive undulator modules, reinforcing the radiation's longitudinal coherence, produced according to a Free Electron Laser (FEL) scheme by the interaction between the electron bunch and a light wave. The very high peak brilliance justifies their designation as fourth generation sources. The number of users is smaller because an electron pulse produces a radiation burst towards only one beamline. Energy Recovery Linacs (ERL) let the beam pass several times in the accelerator structures either to recover the energy or to accelerate the electrons during several turns

  5. Recent trends in particle accelerator radiation safety

    International Nuclear Information System (INIS)

    Ohnesorge, W.F.; Butler, H.M.

    1974-01-01

    The use of particle accelerators in applied and research activities continues to expand, bringing new machines with higher energy and current capabilities which create radiation safety problems not commonly encountered before. An overview is given of these increased ionizing radiation hazards, along with a discussion of some of the new techniques required in evaluating and controlling them. A computer search of the literature provided a relatively comprehensive list of publications describing accelerator radiation safety problems and related subjects

  6. The History and Role of Accelerators in Radiation Oncology

    Science.gov (United States)

    Smith, Alfred

    2003-04-01

    Over one million people are diagnosed with cancer (excluding skin cancer) each year in the United States - about half of those patients will receive radiation as part of their treatment. Radiation Oncology is the field of medicine that specializes in the treatment of cancer with radiation. The evolution of Radiation Oncology, and its success as a cancer treatment modality, has generally paralleled developments in imaging and accelerator technologies. Accelerators, the topic of this paper, have proven to be highly reliable, safe and efficient sources of radiation for cancer treatment. Advances in accelerator technology, especially those that have provided higher energies and dose rates, and more localized (to the tumor volume) dose distributions, have enabled significant improvements in the outcomes of cancer treatments. The use of Cobalt 60 beams has greatly declined in the past decade. Radiation beams used in cancer treatment include x-rays, electrons, protons, negative pions, neutrons, and ions of helium, carbon, neon and silicon. X-rays and electrons, produced by linear electron accelerators, have been the most widely used. The history of medical accelerators can be traced from Roentgen's discovery of x-rays in 1895. The evolution of medical electron accelerators will be discussed and the use of x-ray tubes, electrostatic accelerators, betatrons, and linear accelerators will be described. Heavy particle cancer treatments began in 1955 using proton beams from the Berkeley 184-inch cyclotron. Accelerators that have been used for heavy particle therapy include the Berkeley Bevalac, Los Alamos Pion Facility, Fermi Laboratory, and various research and medical cyclotrons and synchrotrons. Heavy particle accelerators and their application for cancer treatment will be discussed.

  7. Radiation monitoring around accelerator facilities

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Shinichi [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan)

    2000-07-01

    The present status of a network of radiation monitors (NORM) working at KEK is described in detail. NORM consists of there parts; stand-alone radiation monitors (SARM), local-monitoring stations (STATION) and a central data-handling system (CENTER). NORM has developed to a large-scaled monitoring system in which more than 250 SARMs are under operation for monitoring the radiation fields and radioactivities around accelerators in KEK. (author)

  8. Radiation safety and radiation protection problems on the TESLA Accelerator Installation

    International Nuclear Information System (INIS)

    Pavlovic, R.; Pavlovic, S.; Orlic, M.

    1997-01-01

    As we can see from the examples of many accelerator facilities installed throughout the world with ion beam energy, mass and charge characteristics and design similar to the TESLA Accelerator Installation, there is a great diversity among them, and each radiation protection and safety programme must be designed to facilitate the safe and effective operation of the accelerator according to the needs of the operating installation. Although there is no standard radiation protection and safety organization suitable for all institutions, experience suggests some general principles that should be integrated with all the disciplines involved in a comprehensive safety programme. (author)

  9. Radiation protection of the operation of accelerator facilities. On high energy proton and electron accelerators

    International Nuclear Information System (INIS)

    Kondo, Kenjiro

    1997-01-01

    Problems in the radiation protection raised by accelerated particles with energy higher than several hundreds MeV in strong accelerator facilities were discussed in comparison with those with lower energy in middle- and small-scale facilities. The characteristics in the protection in such strong accelerator facilities are derived from the qualitative changes in the interaction between the high energy particles and materials and from quantitative one due to the beam strength. In the former which is dependent on the emitting mechanism of the radiation, neutron with broad energy spectrum and muon are important in the protection, and in the latter, levels of radiation and radioactivity which are proportional to the beam strength are important. The author described details of the interaction between high energy particles and materials: leading to the conclusion that in the electron accelerator facilities, shielding against high energy-blemsstrahlung radiation and -neutron is important and in the proton acceleration, shielding against neutron is important. The characteristics of the radiation field in the strong accelerator facilities: among neutron, ionized particles and electromagnetic wave, neutron is most important in shielding since it has small cross sections relative to other two. Considerations for neutron are necessary in the management of exposure. Multiplicity of radionuclides produced: which is a result of nuclear spallation reaction due to high energy particles, especially to proton. Radioactivation of the accelerator equipment is a serious problem. Other problems: the interlock systems, radiation protection for experimenters and maintenance of the equipment by remote systems. (K.H.). 11 refs

  10. The radiation environment of proton accelerators and storage rings

    International Nuclear Information System (INIS)

    Stevenson, G.R.

    1976-01-01

    These lecture notes survey the physical processes that give rise to the stray-radiation environment of proton synchrotrons and storage rings, with emphasis on their importance for radiation protection. The origins of the prompt radiation field (which disappears when the accelerator is switched off) are described in some detail: proton-nucleus interactions, extranuclear cascades, muon generation and transport. The effects of induced radioactivity in the accelerator structure and surroundings, notably in iron, concrete, air, and water, are discussed and methods for monitoring hadrons in the radiation environment outside the accelerator are listed. Seventy-six references to the literature are included. (Author)

  11. Decease of accelerator size for radiation processing

    International Nuclear Information System (INIS)

    Tanaka, Ryuichi; Sunaga, Hiromi

    2003-01-01

    The decrease of accelerator size is an essential means to improve the market competition power of the radiation processing industry and to expand the wide application. Trials for the decrease or minimization are increasing steadily including development of irradiation equipments for exclusive uses. Compact irradiation systems were outlined for the significance and recent examples of the decrease in radiation processing, the problems in the industrial application, and the future of compact accelerators. (author)

  12. Electromagnetic radiation from a laser wakefield accelerator

    NARCIS (Netherlands)

    Khachatryan, A.G.; van Goor, F.A.; Boller, Klaus J.

    2008-01-01

    Coherent and incoherent electromagnetic radiation emitted from a laser wakefield accelerator is calculated based on Lienard-Wiechert potentials. It is found that at wavelengths longer than the bunch length, the radiation is coherent. The coherent radiation, which typically lies in the infrared

  13. Radiation risk management at DOE accelerator facilities

    International Nuclear Information System (INIS)

    Dyck, O.B. van.

    1997-01-01

    The DOE accelerator contractors have been discussing among themselves and with the Department how to improve radiation safety risk management. This activity-how to assure prevention of unplanned high exposures-is separate from normal exposure management, which historically has been quite successful. The ad-hoc Committee on the Accelerator Safety Order and Guidance [CASOG], formed by the Accelerator Section of the HPS, has proposed a risk- based approach, which will be discussed. Concepts involved are risk quantification and comparison (including with non-radiation risk), passive and active (reacting) protection systems, and probabilistic analysis. Different models of risk management will be presented, and the changing regulatory environment will also be discussed

  14. Distributed Radiation Monitoring System for Linear Accelerators based on CAN Bus

    CERN Document Server

    Kozak, T; Napieralski, A

    2010-01-01

    Abstract—Gamma and neutron radiation is produced during the normal operation of linear accelerators like Free-Electron Laser in Hamburg (FLASH) or X-ray Free Electron Laser (X-FEL). Gamma radiation cause general degeneration of electronics devices and neutron fluence can be a reason of soft error in memories and microcontrollers. X-FEL accelerator will be built only in one tunnel, therefore most of electronic control systems will be placed in radiation environment. Exposing control systems to radiation may lead to many errors and unexpected failure of the whole accelerator system. Thus, the radiation monitoring system able to monitor radiation doses produced near controlling systems is crucial. Knowledge of produced radiation doses allows to detect errors caused by radiation, make plans of essential exchange of control systems and prevent accelerator from serious damages. The paper presents the project of radiation monitoring system able to monitor radiation environment in real time.

  15. A 600 keV electron radiation accelerator

    International Nuclear Information System (INIS)

    Zhou Youyi; Wang Xurong

    1995-01-01

    The authors describe a 600 keV two-body multi-functional electron and positive ion radiation accelerator based on a 400 keV Cockroft-Walton, Which was successfully used to accelerate electron and positive ion. Through test on coating solidification of decoration materials, such as colorful surface plaster plate and relief plate, and researches on metal plate, plastic plate, wood and paper coating decorations and radiation workmanship, as well as experiment of brach-linking by radiation for filling materials of petroleum pipings, it is proved that the device is reliable and stable in operation and reaches the pre-set design indexes and satisfies the requirements called for

  16. Radiation pressure acceleration of ultrathin foils

    Energy Technology Data Exchange (ETDEWEB)

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco [Department of Physics ' E. Fermi' , Largo B Pontecorvo 3, 56127 Pisa (Italy); Liseykina, Tatyana V, E-mail: macchi@df.unipi.i [Max Planck Institute for Nuclear Physics, Heidelberg (Germany)

    2010-04-15

    The acceleration of sub-wavelength, solid-density plasma foils by the ultraintense radiation pressure of circularly polarized laser pulses is investigated analytically and with simulations. An improved 'Light Sail' or accelerating mirror model, accounting for nonlinear self-induced transparency effects, is used for estimating the optimal thickness for acceleration. The model predictions are in good agreement with one-dimensional simulations. These latter are analyzed in detail to unfold the dynamics and self-organization of electrons and ions during the acceleration. Two-dimensional simulations are also performed to address the effects of target bending and of laser intensity inhomogeneity.

  17. Histopathological changes in the irradiated normal organs of guinea pigs with conventional fractionation and hyperfractionation

    International Nuclear Information System (INIS)

    Inomata, Taisuke; Itoh, Satoshi; Tsuboi, Nobuaki

    1998-01-01

    Guinea pigs were divided into groups according to four irradiation schedules : 2 Gy/3 Gy x 1/day, five fractions/week, total 80 Gy/81 Gy (A/C group) and 1.0 Gy/1.5 Gy x 2/day, ten fractions/week, total 80 Gy/81 Gy (B/D group). The A group and the C group pathologically caused severe damage in the kidney six and three months after irradiation, respectively. In the B group pathological analysis suggested that only slight-to-moderate changes were occurred in the Bowman's capsule. The D group caused slight damage in the kidney six months after irradiation. Hyperfractionation (B/D group) used in this protocol can clearly reduce radiation damage in the kidney of guinea pigs as compared with conventional fractionation (A/C group). (author)

  18. Radiation protection around high energy proton accelerators

    International Nuclear Information System (INIS)

    Bourgois, L.

    1996-01-01

    Proton accelerators are intense radiation sources because of the particle beam itself, secondary radiation and structure activation. So radiation protection is required around these equipment during running time but even during downtime. This article presents some estimated values about structure and air activation and applies the Moyer model to get dose rate behind shielding. (A.C.)

  19. Radiation safety aspects at Indus accelerator complex

    International Nuclear Information System (INIS)

    Marathe, R.G.

    2011-01-01

    Indus Accelerator Complex at Raja Ramanna Center for Advanced Technology houses two synchrotron radiation sources Indus-1 and Indus-2 that are being operated round-the-clock to cater to the needs of the research community. Indus-1 is a 450 MeV electron storage ring and Indus-2 is presently being operated with electrons stored at 2 GeV. Bremsstrahlung radiation and photo-neutrons form the major radiation environment in Indus Accelerator Complex. They are produced due to loss of electron-beam occurring at different stages of operation of various accelerators located in the complex. The synchrotron radiation (SR) also contributes as a potential hazard. In order to ensure safety of synchrotron radiation users and operation and maintenance staff working in the complex from this radiation, an elaborate radiation safety system is in place. The system comprises a Personnel Protection System (PPS) and a Radiation Monitoring System (RMS). The PPS includes zoning, radiation shielding, door interlocks, a search and scram system and machine operation trip-interlocks. The RMS consists of area radiation monitors and beam loss monitors, whose data is available online in the Indus control room. Historical data of radiation levels is also available for data analysis. Synchrotron radiation beamlines at Indus-2 are handled in a special manner owing to the possibility of exposure to synchrotron radiation. Shielding hutches with SR monitors are installed at each beamline of Indus-2. Health Physics Unit also carries out regular radiological surveillance for photons and neutrons during various modes of operation and data is logged shift wise. The operation staff is appropriately trained and qualified as per the recommendations of Atomic Energy Regulatory Board (AERB). Safety training is also imparted to the beamline users. Safe operation procedures and operation checklists are being followed strictly. A radiation instrument calibration facility is also being set-up at RRCAT. The radiation

  20. Split Course Hyperfractionated Accelerated Radio-Chemotherapy (SCHARC for patients with advanced head and neck cancer: Influence of protocol deviations and hemoglobin on overall survival, a retrospective analysis

    Directory of Open Access Journals (Sweden)

    Sprague Lisa D

    2006-12-01

    Full Text Available Abstract Background The advantage of hyperfractionated accelerated radiation therapy for advanced head and neck cancer has been reported. Furthermore, randomized trials and meta-analyses have confirmed the survival benefit of additional chemotherapy to radiotherapy. We retrospectively analyzed the efficiency and toxicity of the Regensburg standard therapy protocol "SCHARC" and the overall survival of our patients. Methods From 1997 to 2004, 64 patients suffering from advanced head and neck cancer (88 % stage IV, 12 % stage III were assigned to receive the SCHARC protocol. Around half of the patients were diagnosed with oro-hypopharynx carcinoma (52 %, one third with tongue and floor of mouth tumors (29 % and one fifth (19 % suffered from H & N cancer at other sites. The schedule consisted of one therapy block with 30 Gy in 20 fractions over a two week period with concomitant chemotherapy (d 1–5: 20 mg/m2/d DDP + 750–1000 mg/m2/d 5FU (cont. infusion. This therapy block was repeated after a fortnight break up to a cumulative dose of 60 Gy and followed by a boost up to 70 Gy (69–70.5 Gy. All patients assigned to this scheme were included in the survival evaluation. Results Forty patients (63 % received both radiation and chemotherapy according to the protocol. The mean follow up was 2.3 years (829 d and the median follow up was 1.9 years (678 d, respectively. The analysis of survival revealed an estimated 3 year overall survival rate of 57 %. No patient died of complications, 52 patients (80 % had acute grade 2–3 mucositis, and 33 patients (58 % suffered from acute grade 3 skin toxicity. Leucopenia was no major problem (mean nadir 3.4 g/nl, no patient 10.5 g/dl and for patients who completed the protocol. Conclusion The SCHARC protocol was effective in patients diagnosed with advanced head and neck cancer. It led to long-term disease control and survival in about 50 % of the patients with significant but acceptable toxicity. Most patients

  1. Split Course Hyperfractionated Accelerated Radio-Chemotherapy (SCHARC) for patients with advanced head and neck cancer: Influence of protocol deviations and hemoglobin on overall survival, a retrospective analysis

    International Nuclear Information System (INIS)

    Stadler, Peter; Putnik, Kurt; Kreimeyer, Thore; Sprague, Lisa D; Koelbl, Oliver; Schäfer, Christof

    2006-01-01

    The advantage of hyperfractionated accelerated radiation therapy for advanced head and neck cancer has been reported. Furthermore, randomized trials and meta-analyses have confirmed the survival benefit of additional chemotherapy to radiotherapy. We retrospectively analyzed the efficiency and toxicity of the Regensburg standard therapy protocol 'SCHARC' and the overall survival of our patients. From 1997 to 2004, 64 patients suffering from advanced head and neck cancer (88 % stage IV, 12 % stage III) were assigned to receive the SCHARC protocol. Around half of the patients were diagnosed with oro-hypopharynx carcinoma (52 %), one third with tongue and floor of mouth tumors (29 %) and one fifth (19 %) suffered from H & N cancer at other sites. The schedule consisted of one therapy block with 30 Gy in 20 fractions over a two week period with concomitant chemotherapy (d 1–5: 20 mg/m 2 /d DDP + 750–1000 mg/m 2 /d 5FU (cont. infusion). This therapy block was repeated after a fortnight break up to a cumulative dose of 60 Gy and followed by a boost up to 70 Gy (69–70.5 Gy). All patients assigned to this scheme were included in the survival evaluation. Forty patients (63 %) received both radiation and chemotherapy according to the protocol. The mean follow up was 2.3 years (829 d) and the median follow up was 1.9 years (678 d), respectively. The analysis of survival revealed an estimated 3 year overall survival rate of 57 %. No patient died of complications, 52 patients (80 %) had acute grade 2–3 mucositis, and 33 patients (58 %) suffered from acute grade 3 skin toxicity. Leucopenia was no major problem (mean nadir 3.4 g/nl, no patient < 1.0 g/nl) and the mean hemoglobin value decreased from 13.2 to 10.5 g/dl. Univariate analysis of survival showed a better outcome for patients with a hemoglobin nadir >10.5 g/dl and for patients who completed the protocol. The SCHARC protocol was effective in patients diagnosed with advanced head and neck cancer. It led

  2. Split course hyperfractionated accelerated radio-chemotherapy (SCHARC) for patients with advanced head and neck cancer: influence of protocol deviations and hemoglobin on overall survival, a retrospective analysis.

    Science.gov (United States)

    Stadler, Peter; Putnik, Kurt; Kreimeyer, Thore; Sprague, Lisa D; Koelbl, Oliver; Schäfer, Christof

    2006-12-07

    The advantage of hyperfractionated accelerated radiation therapy for advanced head and neck cancer has been reported. Furthermore, randomized trials and meta-analyses have confirmed the survival benefit of additional chemotherapy to radiotherapy. We retrospectively analyzed the efficiency and toxicity of the Regensburg standard therapy protocol "SCHARC" and the overall survival of our patients. From 1997 to 2004, 64 patients suffering from advanced head and neck cancer (88 % stage IV, 12 % stage III) were assigned to receive the SCHARC protocol. Around half of the patients were diagnosed with oro-hypopharynx carcinoma (52 %), one third with tongue and floor of mouth tumors (29 %) and one fifth (19 %) suffered from H & N cancer at other sites. The schedule consisted of one therapy block with 30 Gy in 20 fractions over a two week period with concomitant chemotherapy (d 1-5: 20 mg/m2/d DDP + 750-1000 mg/m2/d 5FU (cont. infusion). This therapy block was repeated after a fortnight break up to a cumulative dose of 60 Gy and followed by a boost up to 70 Gy (69-70.5 Gy). All patients assigned to this scheme were included in the survival evaluation. Forty patients (63 %) received both radiation and chemotherapy according to the protocol. The mean follow up was 2.3 years (829 d) and the median follow up was 1.9 years (678 d), respectively. The analysis of survival revealed an estimated 3 year overall survival rate of 57 %. No patient died of complications, 52 patients (80 %) had acute grade 2-3 mucositis, and 33 patients (58 %) suffered from acute grade 3 skin toxicity. Leucopenia was no major problem (mean nadir 3.4 g/nl, no patient hemoglobin value decreased from 13.2 to 10.5 g/dl. Univariate analysis of survival showed a better outcome for patients with a hemoglobin nadir >10.5 g/dl and for patients who completed the protocol. The SCHARC protocol was effective in patients diagnosed with advanced head and neck cancer. It led to long-term disease control and survival in

  3. Calibration and application of medical particle accelerators to space radiation experiments

    International Nuclear Information System (INIS)

    Ryu, Kwangsun; Park, Miyoung; Chae, Jangsoo; Yoon, Sangpil; Shin, Dongho

    2012-01-01

    In this paper, we introduce radioisotope facilities and medical particle accelerators that can be applied to space radiation experiments and the experimental conditions required by the space radiation experiments. Space radiation experiments on the ground are critical in determining the lifetimes of satellites and in choosing or preparing the appropriate electrical parts to assure the designated mission lifetime. Before the completion of building the 100-MeV proton linear accelerator in Gyeongju, or even after the completion, the currently existing proton accelerators for medical purposes could suggest an alternative plan. We have performed experiments to calibrate medical proton beam accelerators to investigate whether the beam conditions are suitable for applications to space radiation experiments. Based on the calibration results, we propose reference beam operation conditions for space radiation experiments.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  5. Radiation shielding technology development for proton linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Ouk; Lee, Y. O.; Cho, Y. S. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kim, M. H.; Sin, M. W.; Park, B. I. [Kyunghee Univ., Seoul (Korea, Republic of)] [and others

    2005-09-01

    This report was presented as an output of 2-year project of the first phase Proton Engineering Frontier Project(PEFP) on 'Radiation Shielding Technology Development for Proton Linear Accelerator' for 20/100 MeV accelerator beam line and facility. It describes a general design concept, provision and update of basic design data, and establishment of computer code system. It also includes results of conceptual and preliminary designs of beam line, beam dump and beam facilities as well as an analysis of air-activation inside the accelerator equipment. This report will guides the detailed shielding design and production of radiation safety analysis report scheduled in the second phase project.

  6. Suppression of X-radiation from 2 MeV ion electrostatic accelerator

    International Nuclear Information System (INIS)

    Ignat'ev, I.G.; Miroshnichenko, V.I.; Sirenko, A.M.; Storizhko, V.E.

    2008-01-01

    The paper presents results concerning studies of X-radiation from 2 MeV ion electrostatic accelerator 'Sokol' used for nuclear microprobe analysis. The radiation protection system of the accelerator was developed and tested. Tests of the system of the accelerator show that it reduces doses rate by two orders of magnitude

  7. A prospective randomized trial of hyperfractionated versus conventional once daily radiation for advanced squamous cell carcinomas of the larynx and pharynx

    International Nuclear Information System (INIS)

    Cummings, B.J.; Keane, T.J.; Pintilie, M.; O'Sullivan, B.; Payne, D.; Warde, P.; McLean, M.; Waldron, J.; Liu, F.-F.; Gullane, P.

    1996-01-01

    Purpose: To examine the effects of an increased dose of radiation therapy (RT) delivered by a hyperfractionated schedule compared to conventional once daily RT on toxicity, locoregional control and survival in the treatment of squamous cell carcinomas (SCC) of the larynx and pharynx. Materials/Methods: Between 1988 and 1995 336 patients were randomized to receive RT with curative intent. Eligible patients had biopsy proven SCC of the larynx or pharynx, with TN stages (AJC-UICC 1987) T3 or T4 N0, or any T with any N+. All patients were M0. Patients were stratified by site (larynx/oropharynx/hypopharynx), node status (clinically positive/negative), and performance status. Patients were treated with either 51 Gy TAD/20 fractions/4 wk (2.55 Gy 1x/d, conventional RT=CRT) or 58 Gy TAD/40 fractions/4 wk (1.45 Gy 2x/d, hyperfractionated RT=HFRT). Patients underwent EUA and selective biopsies 10 wk after RT; surgical salvage was performed for residual or recurrent cancer whenever possible. Results: The primary cancer arose in the oropharynx (138), larynx (133) or hypopharynx (65). T stages were distributed T1 22, T2 72, T3 133 and T4 109. N stage distribution was N0 127, N1 74, N2 117 and N3 18. The proportion of patients with acute mucosal toxicity (RTOG Grade 3 or 4) was increased by HFRT (60% versus 40%), but other acute and late toxicity was not significantly different. There was no difference in the incidence of morbidity in the two treatment groups in those who underwent surgery following RT. The locoregional control rates at 3 yrs for all cases were 45% (HFRT) vs 40% (CRT) log rank p=0.16; for primary tumors <4 cm 54% (HFRT) vs 42% (CRT) p=0.04; for primary tumors ≥ 4 cm 38% (HFRT) vs 41% (CRT) p=0.73. Local control was improved to some extent in SCC which arose in all sites, but most noticeably in hypopharyngeal cancers. The disease free survival rates at 3 yr for all cases were 37% (HFRT) vs 30% (CRT) p=0.15; for primary tumors < 4 cm 47% (HFRT) vs 34% (CRT) p=0

  8. The Automatic Radiation Control System Of The Inr Linear Accelerator (troitsk).

    CERN Document Server

    Grachev, M I; Kuptsov, S I; Peleshko, V N; Shishkin, K I; Shmelev, M O; Skorkin, V M

    2004-01-01

    The radiation monitor system (RMS) at accelerator INR is a part of radiation safety system of experimental complex INR. RMS is intended for continuous monitoring of radiation field behind biological protection of linear accelerator INR with the personnel dose control and alarm purposes. Three-level system RMS consists of the operator computer, microprocessor data acquisition modules and networks of UDBN-02R neutron detectors and BDRC-01P photon detectors, located inside and behind biological protection of the accelerator (fig. 1).

  9. Photon acceleration-based radiation sources

    International Nuclear Information System (INIS)

    Hoffman, J. R.; Muggli, P.; Katsouleas, T.; Mori, W. B.; Joshi, C.

    1999-01-01

    The acceleration and deceleration of photons in a plasma provides the means for a series of new radiation sources. Previous work on a DC to AC Radiation Converter (DARC source) has shown variable acceleration of photons having zero frequency (i.e., an electrostatic field) to between 6 and 100 GHz (1-3). These sources all had poor guiding characteristics resulting in poor power coupling from the source to the load. Continuing research has identified a novel way to integrate the DARC source into a waveguide. The so called ''pin structure'' uses stainless steel pins inserted through the narrow side of an X band waveguide to form the electrostatic field pattern (k≠0, ω=0). The pins are spaced such that the absorption band resulting from this additional periodic structure is outside of the X band range (8-12 GHz), in which the normal waveguide characteristics are left unchanged. The power of this X band source is predicted theoretically to scale quadratically with the pin bias voltage as -800 W/(kV) 2 and have a pulse width of -1 ns. Cold tests and experimental results are presented. Applications for a high power, short pulse radiation source extends to the areas of landmine detection, improved radar resolution, and experimental investigations of molecular systems

  10. Calculating the radiation characteristics of accelerated electrons in laser-plasma interactions

    International Nuclear Information System (INIS)

    Li, X. F.; Yu, Q.; Qu, J. F.; Kong, Q.; Gu, Y. J.; Ma, Y. Y.; Kawata, S.

    2016-01-01

    In this paper, we studied the characteristics of radiation emitted by electrons accelerated in a laser–plasma interaction by using the Lienard–Wiechert field. In the interaction of a laser pulse with a underdense plasma, electrons are accelerated by two mechanisms: direct laser acceleration (DLA) and laser wakefield acceleration (LWFA). At the beginning of the process, the DLA electrons emit most of the radiation, and the DLA electrons emit a much higher peak photon energy than the LWFA electrons. As the laser–plasma interaction progresses, the LWFA electrons become the major radiation emitter; however, even at this stage, the contribution from DLA electrons is significant, especially to the peak photon energy.

  11. Unlimited ion acceleration by radiation pressure.

    Science.gov (United States)

    Bulanov, S V; Echkina, E Yu; Esirkepov, T Zh; Inovenkov, I N; Kando, M; Pegoraro, F; Korn, G

    2010-04-02

    The energy of ions accelerated by an intense electromagnetic wave in the radiation pressure dominated regime can be greatly enhanced due to a transverse expansion of a thin target. The expansion decreases the number of accelerated ions in the irradiated region resulting in an increase in the ion energy and in the ion longitudinal velocity. In the relativistic limit, the ions become phase locked with respect to the electromagnetic wave resulting in unlimited ion energy gain.

  12. Radiation from Accelerating Electric Charges: The Third Derivative of Position

    Science.gov (United States)

    Butterworth, Edward

    2010-03-01

    While some textbooks appear to suggest that acceleration of an electric charge is both a necessary and sufficient cause for the generation of electromagnetic radiation, the question has in fact had an intricate and involved history. In particular, the acceleration of a charge in hyperbolic motion, the behavior of a charge supported against a gravitational force (and its implications for the Equivalence Principle), and a charge accelerated by a workless constraint have been the subject of repeated investigation. The present paper examines specifically the manner in which the third derivative of position enters into the equations of motion, and the implications this has for the emission of radiation. Plass opens his review article with the statement that ``A fundamental property of all charged particles is that electromagnetic energy is radiated whenever they are accelerated'' (Plass 1961; emphasis mine). His treatment of the equations of motion, however, emphasizes the importance of the occurrence of the third derivative of position therein, present in linear motion only when the rate of acceleration is increasing or decreasing. There appears to be general agreement that the presence of a nonzero third derivative indicates that this charge is radiating; but does its absence preclude radiation? This question leads back to the issues of charges accelerated by a uniform gravitational field. We will examine the equations of motion as presented in Fulton & Rohrlich (1960), Plass (1961), Barut (1964), Teitelboim (1970) and Mo & Papas (1971) in the light of more recent literature in an attempt to clarify this question.

  13. Does electromagnetic radiation accelerate galactic cosmic rays

    Science.gov (United States)

    Eichler, D.

    1977-01-01

    The 'reactor' theories of Tsytovich and collaborators (1973) of cosmic-ray acceleration by electromagnetic radiation are examined in the context of galactic cosmic rays. It is shown that any isotropic synchrotron or Compton reactors with reasonable astrophysical parameters can yield particles with a maximum relativistic factor of only about 10,000. If they are to produce particles with higher relativistic factors, the losses due to inverse Compton scattering of the electromagnetic radiation in them outweigh the acceleration, and this violates the assumptions of the theory. This is a critical restriction in the context of galactic cosmic rays, which have a power-law spectrum extending up to a relativistic factor of 1 million.

  14. Radiation protection systems on the TESLA Accelerator Installation

    International Nuclear Information System (INIS)

    Pavlovic, R.

    1996-01-01

    In the Institute of Nuclear sciences VINCA, the Accelerator Installation TESLA which is an medium energy ion accelerator facility consisting of an isochronous cyclotron VINCY, a heavy ion source, a D/H ion source, three low energy and five high energy experimental channels is now under construction. Some problems in defining radiation protection and safety programme, particularly problems in construction appropriate shielding barriers at the Accelerator Installation TESLA are discussed in this paper. (author

  15. Costs of conventional radical radiotherapy versus continuous hyperfractionated accelerated radiotherapy (CHART) in the treatment of patients with head and neck cancer or carcinoma of the bronchus. Medical Research Council CHART Steering Committee.

    Science.gov (United States)

    Coyle, D; Drummond, M F

    1997-01-01

    The objective of this study was to compare the costs of treatment with continuous hyperfractionated accelerated radiotherapy (CHART) and those of conventional radiotherapy for patients with (1) head and neck cancer and (2) carcinoma of the bronchus. The study was conducted concurrently with two multicentre randomized controlled trials. Data were collected on the use of hospital and community service resources and patients' travel for treatment. Data on resource use up to 3 months after entry to the study were available for 526 head and neck patients (314 receiving CHART and 212 conventional therapy) and 284 bronchus patients (175 CHART and 109 conventional therapy). For patients with head and neck cancer, CHART cost Pounds 1092 (P hostel facilities. The results of this cost analysis will help to facilitate a decision about whether the benefits of CHART, as determined by the clinical trials, are worth the additional costs of hospital-based resource use. The collection of detailed patient-specific resource-use data from a number of centres allows the determination of ways for reducing the cost differential between therapies and making CHART a more cost effective treatment alternative.

  16. Measurement of the radiation in the accelerator-therapy room

    International Nuclear Information System (INIS)

    Zutz, Hayo

    2013-01-01

    The measurement of the scattering radiation in the accelerator-therapy room of the PTB is described. The accelerators are commercial linear accelerators of the firm Elektra of the type ''Precise''. The measurements were performed by means of secondary-normal ionization chambers and a special measurement technique developed in the PTB both with and without the used beam. (HSI)

  17. Induction-linear accelerators for food processing with ionizing radiation

    International Nuclear Information System (INIS)

    Lagunas-Solar, M.C.

    1985-01-01

    Electron accelerators with sufficient beam power and reliability of operation will be required for applications in the large-scale radiation processing of food. Electron beams can be converted to the more penetrating bremsstrahlung radiation (X-rays), although at a great expense in useful X-ray power due to small conversion efficiencies. Recent advances in the technology of pulse-power accelerators indicates that Linear Induction Electron Accelerators (LIEA) are capable of sufficiently high-beam current and pulse repetition rate, while delivering ultra-short pulses of high voltage. The application of LIEA systems in food irradiation provides the potential for high product output and compact, modular-type systems readily adaptable to food processing facilities. (orig.)

  18. Dusty Cloud Acceleration by Radiation Pressure in Rapidly Star-forming Galaxies

    Science.gov (United States)

    Zhang, Dong; Davis, Shane W.; Jiang, Yan-Fei; Stone, James M.

    2018-02-01

    We perform two-dimensional and three-dimensional radiation hydrodynamic simulations to study cold clouds accelerated by radiation pressure on dust in the environment of rapidly star-forming galaxies dominated by infrared flux. We utilize the reduced speed of light approximation to solve the frequency-averaged, time-dependent radiative transfer equation. We find that radiation pressure is capable of accelerating the clouds to hundreds of kilometers per second while remaining dense and cold, consistent with observations. We compare these results to simulations where acceleration is provided by entrainment in a hot wind, where the momentum injection of the hot flow is comparable to the momentum in the radiation field. We find that the survival time of the cloud accelerated by the radiation field is significantly longer than that of a cloud entrained in a hot outflow. We show that the dynamics of the irradiated cloud depends on the initial optical depth, temperature of the cloud, and intensity of the flux. Additionally, gas pressure from the background may limit cloud acceleration if the density ratio between the cloud and background is ≲ {10}2. In general, a 10 pc-scale optically thin cloud forms a pancake structure elongated perpendicular to the direction of motion, while optically thick clouds form a filamentary structure elongated parallel to the direction of motion. The details of accelerated cloud morphology and geometry can also be affected by other factors, such as the cloud lengthscale, reduced speed of light approximation, spatial resolution, initial cloud structure, and dimensionality of the run, but these have relatively little affect on the cloud velocity or survival time.

  19. Design concept of radiation control system for the high intensity proton accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Yukihiro; Ikeno, Koichi; Akiyama, Shigenori; Harada, Yasunori [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2002-11-01

    Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics. (author)

  20. Concurrent platinum-based chemotherapy and hyperfractionated radiotherapy with late intensification in advanced head and neck cancer

    International Nuclear Information System (INIS)

    Glicksman, Arvin S.; Wanebo, Harold J.; Slotman, Gus; Liu Li; Landmann, Christine; Clark, Jeffrey; Zhu, Timothy C.; Lohri, Andreas; Probst, Rudolf

    1997-01-01

    Purpose: To determine whether a course of hyperfractionated radiation therapy concomitant with escalated radiosensitizing platinum compounds can be administered with acceptable morbidity and achieve a high rate of loco-regional control for Stage III and IV head and neck cancer and whether the patients can be tumor free at the primary site after initial therapy and cured by the additional chemoradiation without radical resection of the primary tumor. Methods and Materials: Patients with Stage III/IV head and neck cancer were treated in this multicenter Phase II Study with 1.8 Gy fraction radiotherapy for 2 weeks, with escalation to 1.2 Gy b.i.d. hyperfractionation to 46.8 Gy. Concomitant continuous infusion cisplatinum (CDDP) 20 mg per meter square on day 1 to 4 and 22 to 25 was given. Reassessment by biopsy of primary and nodes was done. Patients with a complete response continued with hyperfractionated radiotherapy to 75.6 Gy with simultaneous carboplatinum (Carbo), 25 mg per meter square b.i.d. for 12 consecutive treatment days. Patients with residual disease at 46.8 Gy required curative surgery. Seventy-four patients were treated at the three institutions; 20 were Stage III and 54 were Stage IV. All patients had daily mouth care, nutritional, and psychosocial support. Results: This regime was well tolerated. Eighty-five percent of toxicities were Grade 1 or 2 and there was only one Grade 4 hematologic toxicity. Late toxicities included xerostomia in 25 patients, dysplasia in 18, and mild speech impediment in 11. Biopsies of primary site were done after the first course of treatment in 59 patients. Neck dissections were performed in 35 patients. Forty-four of 59 (75%) primary sites and 16 of 35 (46%) lymph nodes had pathologically complete response (CR). Of the 74 patients, only 12 required surgical resection of the primary site. Thirty-five of the 50 node positive patients had neck dissections, 16 of these were CRs at surgery. At 4 years (median follow-up of 26

  1. Radiation dose-dependent change in brain 1H-MRS

    International Nuclear Information System (INIS)

    Matsushima, Shigeru; Muroka, Mamoru; Uchiyama, Yukio; Morita, Kozo; Nomoto, Yoshihito; Kinosada, Yasutomi.

    1994-01-01

    We have investigated the usefulness of 1 H-magnetic resonance spectroscopy ( 1 H-MRS) for the assessment of acute radiation damage of the human brain. Nineteen patients were treated with the whole brain irradiation. Biochemical changes in white matter were measured by in vivo 1 H-MRS. The measurement was performed 1 or 2 times in each case at radiation doses ranging from 0 to 44.4 Gy with conventional fractionation (2 Gy per fraction, once a day) or accelerated hyperfractionation (1.5 Gy per fraction, twice a day). For the measurement of 1 H-MRS, 1.5T whole body MR system was used and stimulated echo acquisition mode (STEAM) with chemical shift selective (CHESS) pulse was applied. Volume of the interest (VOI) was 2.5 x 2.5 x 2.5 cm 3 , and the repetition time and echo time were 2000 ms and 272 ms, respectively. The acute radiation damage of the brain was evaluated by the change of peak area ratio (PAR) of choline, creatine and N-acetylaspartate (NAA). 1 H-MR spectra obtained before irradiation were different from those observed during irradiation. There were statistically significant (p 1 H-MRS can be useful for assessment of acute radiation damage. (author)

  2. Study of cell cycle and apoptosis after radiation with electron linear accelerator injury

    International Nuclear Information System (INIS)

    Xu Lan; Zhou Yinghui; Shi Ning; Peng Miao; Wu Shiliang

    2002-01-01

    Purpose: To determine the cell cycle and apoptosis of the injured cells after radiation with the electron linear accelerator. Methods: NIH 3T3 cells were irradiated by the radiation with the electron linear accelerator. In the experiment the condition of the cell cycle and apoptosis of the injured cells were measured. The expression of p53 was also tested. Results: After exposure to radiation, the number of apoptotic cells as well as the expression of p53 increased. Conclusion: The electron linear accelerator radiation injury can induce cell apoptosis

  3. Radiation effects on semiconductor devices in high energy heavy ion accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Belousov, Anton

    2014-10-20

    Radiation effects on semiconductor devices in GSI Helmholtz Center for Heavy Ion Research are becoming more and more significant with the increase of beam intensity due to upgrades. Moreover a new accelerator is being constructed on the basis of GSI within the project of facility for antiproton and ion research (FAIR). Beam intensities will be increased by factor of 100 and energies by factor of 10. Radiation fields in the vicinity of beam lines will increase more than 2 orders of magnitude and so will the effects on semiconductor devices. It is necessary to carry out a study of radiation effects on semiconductor devices considering specific properties of radiation typical for high energy heavy ion accelerators. Radiation effects on electronics in accelerator environment may be divided into two categories: short-term temporary effects and long-term permanent degradation. Both may become critical for proper operation of some electronic devices. This study is focused on radiation damage to CCD cameras in radiation environment of heavy ion accelerator. Series of experiments with irradiation of devices under test (DUTs) by secondary particles produced during ion beam losses were done for this study. Monte Carlo calculations were performed to simulate the experiment conditions and conditions expected in future accelerator. Corresponding comparisons and conclusions were done. Another device typical for accelerator facilities - industrial Ethernet switch was tested in similar conditions during this study. Series of direct irradiations of CCD and MOS transistors with heavy ion beams were done as well. Typical energies of the primary ion beams were 0.5-1 GeV/u. Ion species: from Na to U. Intensities of the beam up to 10{sup 9} ions/spill with spill length of 200-300 ns. Criteria of reliability and lifetime of DUTs in specific radiation conditions were formulated, basing on experimental results of the study. Predictions of electronic device reliability and lifetime were

  4. Management of radiation-induced accelerated carotid atherosclerosis

    International Nuclear Information System (INIS)

    Loftus, C.M.; Biller, J.; Hart, M.N.; Cornell, S.H.; Hiratzka, L.F.

    1987-01-01

    Patients with long survival following cervical irradiation are at risk for accelerated carotid atherosclerosis. The neurologic presentation in these patients mimics naturally occurring atheromatous disease, but patients often present at younger ages and with less concurrent coronary or systemic vascular disease. Hypercholesterolemia also contributes to this accelerated arteriosclerosis. Angiographic findings in this disorder include disproportionate involvement of the distal common carotid artery and unusually long carotid lesions. Pathologic findings include destruction of the internal elastic lamina and replacement of the normal intima and media with fibrous tissue. This article describes two surgical patients with radiation-induced accelerated carotid atherosclerosis who typify the presentation and characteristics of this disease

  5. Generation of auroral kilometric radiation and the structure of auroral acceleration region

    International Nuclear Information System (INIS)

    Lee, L.C.; Kan, J.R.; Wu, C.S.

    1980-01-01

    Generation of auroral kilometric radiation (AKR) in the auroral acceleration region is studied. It is shown that auroral kilometric radiation can be generated by the backscattered electrons trapped in the acceleration region via a cyclotron maser process. The parallel electric field in the acceleration region is required to be distributed over 1-2 Rsub(E). The observed AKR frequency spectrum can be used to estimate the altitude range of the auroral acceleration region. The altitudes of the lower and upper boundaries of the acceleration region determined from the AKR data are respectively approximately 2000 and approximately 9000 km. (author)

  6. Radiations effects on polymeric materials used in CERN particles accelerators

    International Nuclear Information System (INIS)

    Tavlet, M.

    1997-01-01

    For fundamental research on the basis structure of matter, the European Organization for Nuclear Research (CERN) operates several high-energy particle accelerators around which materials and components are exposed to ionizing radiation. To ensure a safe and reliable operation, the radiation behaviour of most of the components is systematically tested prior to their selection. The long-term radiation-test programme allows to assess the component lifetime in the environment or our accelerators where the absorbed doses are continuously recorded. This article presents organic materials in use at CERN, and some recent results are given on their behaviour under irradiation. (authors)

  7. Reliability of high power electron accelerators for radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Zimek, Z. [Department of Radiation Chemistry and Technology, Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    2011-07-01

    Accelerators applied for radiation processing are installed in industrial facilities where accelerator availability coefficient should be at the level of 95% to fulfill requirements according to industry standards. Usually the exploitation of electron accelerator reviles the number of short and few long lasting failures. Some technical shortages can be overcome by practical implementation the experience gained in accelerator technology development by different accelerator manufactures. The reliability/availability of high power accelerators for application in flue gas treatment process must be dramatically improved to meet industrial standards. Support of accelerator technology dedicated for environment protection should be provided by governmental and international institutions to overcome accelerator reliability/availability problem and high risk and low direct profit in this particular application. (author)

  8. Reliability of high power electron accelerators for radiation processing

    International Nuclear Information System (INIS)

    Zimek, Z.

    2011-01-01

    Accelerators applied for radiation processing are installed in industrial facilities where accelerator availability coefficient should be at the level of 95% to fulfill requirements according to industry standards. Usually the exploitation of electron accelerator reviles the number of short and few long lasting failures. Some technical shortages can be overcome by practical implementation the experience gained in accelerator technology development by different accelerator manufactures. The reliability/availability of high power accelerators for application in flue gas treatment process must be dramatically improved to meet industrial standards. Support of accelerator technology dedicated for environment protection should be provided by governmental and international institutions to overcome accelerator reliability/availability problem and high risk and low direct profit in this particular application. (author)

  9. Comparison of two dimensional and three dimensional radiotherapy treatment planning in locally advanced non-small cell lung cancer treated with continuous hyperfractionated accelerated radiotherapy weekend less

    International Nuclear Information System (INIS)

    Wilson, Elena M.; Joy Williams, Frances; Ethan Lyn, Basil; Aird, Edwin G.A.

    2005-01-01

    Background and purpose: Patients with inoperable non-small cell lung cancer being treated with continuous hyperfractionated accelerated radiotherapy weekend less (CHARTWEL) were planned and treated with a three dimensional (3D) conformal protocol and comparison made with two dimensional (2D) planning, as used previously, to compare past practice and methods. Patients and methods: Twenty-four patients were planned initially using 3D and then replanned using a 2D system. The 2D plans were transferred onto the 3D system and recalculated. Dose volume histograms could then be constructed of planning target volumes for phases 1 and 2 (PTV 1 and 2, respectively), lung and spinal cord for the 2D plans and compared with the 3D plans. Results: There was a significantly lower absolute dose to the isocentre with 2D compared to 3D planning with dose reductions of 3.9% for phase 1, 4.4% for phase 2 and 4.7% for those treated with a single phase. Maximum dose to spinal cord was greater in 17 of the 24 2D plans with a median dose reduction of 0.82 Gy for 3D (P=0.04). The percentage volume of whole lung receiving ≥20 Gy (V 20 ) was greater in 16 of the 24 2D plans with a median reduction in V 20 of 2.4% for 3D (P=0.03). Conclusions: A lower dose to tumour was obtained using 2D planning due to the method of dose calculation and spinal cord and lung doses were significantly higher

  10. Morphological correlates of fractionated radiation of the mouse lung: Early and late effects

    International Nuclear Information System (INIS)

    Penney, D.P.; Siemann, D.W.; Rubin, P.; Maltby, K.

    1994-01-01

    The definition and quantitation of radiation-induced morphologic alterations in murine lungs is presented. The extent of injury to the lung, which is the dose-limiting organ in the thorax, may be reduced by fractionating the total radiation exposure to permit partial repair of radiation-induced damage between fraction administration and also to permit a larger total exposure to be administered. The authors previously reported that, following fractionated radiation exposures, as the dose/fraction decreases, the total dose to reach an isoeffect increases, with an α/β ratio of 3.2 and 3.0 for breathing rates and lethality, respectively. In the present report, they provide comparative morphologic evaluation of the effects of weekly fractionated, daily fractionated, and hyperfractionated radiation exposures. The doses administered within each group were uniform. To determine morphologic alterations, LAF1 mice were irradiated with 3, 15, and 30 fractions delivered in 19 days overall treatment time. In the hyperfractionation schedule, the two fractions per day were separated by a 6-h time interval. Total doses were as follows: 15-21 Gy for weekly fractionation, 30-41.5 Gy for daily fractionation, and 30-49.5 Gy for hyperfractionated schedules. Lung tissue, recovered either 24 or 72 weeks following the final exposure, was evaluated by transmission and scanning electron microscopy and light microscopy. Morphological damage was not uniform throughout the exposed lung and tended to be concentrated in lobes or portions of lobes. In the three fractionation regimens studied, there is progressive sparing of the lung with increased fractionation during the pnuemonitic state (24 weeks postirradiation). Both daily and twice daily fractionations provide increased sparing over weekly fractionation during the fibrotic stages (72 weeks postirradiation), but were not markedly different from each other (i.e. weekly < daily = twice daily). 41 refs., 15 figs., 2 tabs

  11. Early Clinical Outcomes Demonstrate Preserved Cognitive Function in Children With Average-Risk Medulloblastoma When Treated With Hyperfractionated Radiation Therapy

    International Nuclear Information System (INIS)

    Gupta, Tejpal; Jalali, Rakesh; Goswami, Savita; Nair, Vimoj; Moiyadi, Aliasgar; Epari, Sridhar; Sarin, Rajiv

    2012-01-01

    Purpose: To report on acute toxicity, longitudinal cognitive function, and early clinical outcomes in children with average-risk medulloblastoma. Methods and Materials: Twenty children ≥5 years of age classified as having average-risk medulloblastoma were accrued on a prospective protocol of hyperfractionated radiation therapy (HFRT) alone. Radiotherapy was delivered with two daily fractions (1 Gy/fraction, 6 to 8 hours apart, 5 days/week), initially to the neuraxis (36 Gy/36 fractions), followed by conformal tumor bed boost (32 Gy/32 fractions) for a total tumor bed dose of 68 Gy/68 fractions over 6 to 7 weeks. Cognitive function was prospectively assessed longitudinally (pretreatment and at specified posttreatment follow-up visits) with the Wechsler Intelligence Scale for Children to give verbal quotient, performance quotient, and full-scale intelligence quotient (FSIQ). Results: The median age of the study cohort was 8 years (range, 5–14 years), representing a slightly older cohort. Acute hematologic toxicity was mild and self-limiting. Eight (40%) children had subnormal intelligence (FSIQ <85), including 3 (15%) with mild mental retardation (FSIQ 56–70) even before radiotherapy. Cognitive functioning for all tested domains was preserved in children evaluable at 3 months, 1 year, and 2 years after completion of HFRT, with no significant decline over time. Age at diagnosis or baseline FSIQ did not have a significant impact on longitudinal cognitive function. At a median follow-up time of 33 months (range, 16–58 months), 3 patients had died (2 of relapse and 1 of accidental burns), resulting in 3-year relapse-free survival and overall survival of 83.5% and 83.2%, respectively. Conclusion: HFRT without upfront chemotherapy has an acceptable acute toxicity profile, without an unduly increased risk of relapse, with preserved cognitive functioning in children with average-risk medulloblastoma.

  12. Early Clinical Outcomes Demonstrate Preserved Cognitive Function in Children With Average-Risk Medulloblastoma When Treated With Hyperfractionated Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Tejpal, E-mail: tejpalgupta@rediffmail.com [Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer and Tata Memorial Hospital, Mumbai (India); Jalali, Rakesh [Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer and Tata Memorial Hospital, Mumbai (India); Goswami, Savita [Department of Clinical Psychology and Psychiatry Unit, Advanced Centre for Treatment Research and Education in Cancer and Tata Memorial Hospital, Mumbai (India); Nair, Vimoj [Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer and Tata Memorial Hospital, Mumbai (India); Moiyadi, Aliasgar [Division of Neuro-Surgery, Department of Surgical Oncology, Advanced Centre for Treatment Research and Education in Cancer and Tata Memorial Hospital, Mumbai (India); Epari, Sridhar [Department of Pathology, Advanced Centre for Treatment Research and Education in Cancer and Tata Memorial Hospital, Mumbai (India); Sarin, Rajiv [Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer and Tata Memorial Hospital, Mumbai (India)

    2012-08-01

    Purpose: To report on acute toxicity, longitudinal cognitive function, and early clinical outcomes in children with average-risk medulloblastoma. Methods and Materials: Twenty children {>=}5 years of age classified as having average-risk medulloblastoma were accrued on a prospective protocol of hyperfractionated radiation therapy (HFRT) alone. Radiotherapy was delivered with two daily fractions (1 Gy/fraction, 6 to 8 hours apart, 5 days/week), initially to the neuraxis (36 Gy/36 fractions), followed by conformal tumor bed boost (32 Gy/32 fractions) for a total tumor bed dose of 68 Gy/68 fractions over 6 to 7 weeks. Cognitive function was prospectively assessed longitudinally (pretreatment and at specified posttreatment follow-up visits) with the Wechsler Intelligence Scale for Children to give verbal quotient, performance quotient, and full-scale intelligence quotient (FSIQ). Results: The median age of the study cohort was 8 years (range, 5-14 years), representing a slightly older cohort. Acute hematologic toxicity was mild and self-limiting. Eight (40%) children had subnormal intelligence (FSIQ <85), including 3 (15%) with mild mental retardation (FSIQ 56-70) even before radiotherapy. Cognitive functioning for all tested domains was preserved in children evaluable at 3 months, 1 year, and 2 years after completion of HFRT, with no significant decline over time. Age at diagnosis or baseline FSIQ did not have a significant impact on longitudinal cognitive function. At a median follow-up time of 33 months (range, 16-58 months), 3 patients had died (2 of relapse and 1 of accidental burns), resulting in 3-year relapse-free survival and overall survival of 83.5% and 83.2%, respectively. Conclusion: HFRT without upfront chemotherapy has an acceptable acute toxicity profile, without an unduly increased risk of relapse, with preserved cognitive functioning in children with average-risk medulloblastoma.

  13. Lepton accelerators and radiation sources: R and D investment at BNL

    International Nuclear Information System (INIS)

    Ben-Zvi, I.; Fernow, R.; Gallardo, J.; Hart, M.; Hastings, J.; Johnson, E.; Krinsky, S.; Palmer, R.; Yu, L.H.

    1997-03-01

    Brookhaven National Laboratory (BNL) has shown its determination to remain at the forefront of accelerator based science through its continued investment in long range accelerator R and D. The laboratory has a broad program in accelerator technology development including projects such as high T c magnets at RHIC, Siberian Snakes at the AGS, brightness upgrades on the NSLS storage ring, and spallation source R and D in several departments. This report focuses on a segment of the overall program: the lepton accelerator and coherent radiation source R and D at the laboratory. These efforts are aimed at (1) development of high brightness electron beams, (2) novel acceleration techniques, (3) seeded Free Electron Laser (FEL) development, and (4) R and D for a muon collider. To pursue these objectives, BNL ha over the past decade introduced new organizational arrangements. The BNL Center for Accelerator Physics (CAP) is an interdepartmental unit dedicated to promoting R and D which, cannot be readily conducted within the programs of operating facilities. The Accelerator Test Facility (ATF) is managed by CAP and NSLS as a user facility dedicated to accelerator and beam physics problems of interest to both the High Energy Physics and Basic Energy Sciences programs of the DOE. Capitalizing on these efforts, the Source Development Laboratory (SDL) was established by the NSLS to facilitate coordinated development of sources and experiments to produce and utilize coherent sub-picosecond synchrotron radiation. This White Paper describes the programs being pursued at CAP, ATF and SDL aimed at advancing basic knowledge of lepton accelerators and picosecond radiation sources

  14. Environmental impact assessment methods of the radiation generated by the runing medical linear accelerator

    International Nuclear Information System (INIS)

    Yin haihua; Yao Zhigang

    2014-01-01

    This article describes the environmental impact assessment methods of the radiation generated by the runing. medical linear accelerator. The material and thickness of shielding wall and protective doors of the linear accelerator were already knew, therefore we can evaluate the radiation by the runing. medical linear accelerator whether or not in the normal range of national standard by calculating the annual effective radiation dose of the surrounding personnel suffered. (authors)

  15. Locoregionally advanced carcinoma of the oropharynx: conventional radiotherapy vs. accelerated hyperfractionated radiotherapy vs. concomitant radiotherapy and chemotherapy - a multicenter randomized trial

    International Nuclear Information System (INIS)

    Olmi, Patrizia; Crispino, Sergio; Fallai, Carlo; Torri, Valter; Rossi, Francesca; Bolner, Andrea; Amichetti, Maurizio; Signor, Marco; Taino, Raffaella; Squadrelli, Massimo; Colombo, Alessandro; Ardizzoia, Alessandro; Ponticelli, Pietro; Franchin, Giovanni; Minatel, Emilio; Gobitti, Carlo; Atzeni, Guido; Gava, Alessandro; Flann, Monica; Marsoni, Silvia

    2003-01-01

    Purpose: To compare conventional fractionation radiation therapy (RT), Arm A, vs. split-course accelerated hyperfractionated RT (S-AHF), Arm B, vs. conventional fractionation RT plus concomitant chemotherapy (CT), Arm C, in terms of survival and toxicity for advanced, unresectable epidermoid tumors of oropharynx. Methods and Materials: Between January 1993 and June 1998, 192 previously untreated patients affected with Stage III and IV oropharyngeal carcinoma (excluding T1N1 and T2N1) were accrued in a multicenter, randomized Phase III trial (ORO 93-01). For Arms A and C, 66-70 Gy in 33-35 fractions, 5 days a week, were administered in 6.5-7 weeks to tumor and positive nodes. In Arm B, the dose delivered to tumor and involved nodes was 64-67.2 Gy, giving 2 fractions of 1.6 Gy every day with an interfraction interval of at least 4 h and preferably 6 h, 5 days a week. At 38.4 Gy, a 2-week split was planned; after the split, RT was resumed with the same modality. In Arm C, CT regimen consisted of carboplatin and 5-fluorouracil (CBDCA 75 mg/m 2 , Days 1-4; 5-FU 1,000 mg/m 2 i.v. over 96 h, Days 1-4, recycling every 28 days (at 1st, 5th, and 9th week). Results: No statistically significant difference was detected in overall survival (p=0.129): 40% Arm A vs. 37% Arm B vs. 51% Arm C were alive at 24 months. Similarly, there was no statistically significant difference in terms of event-free survival (p=0.196): 20% for Arm A, 19% for Arm B, and 37% for Arm C were event free at 24 months. On the contrary, the 2-year disease-free survival was significantly different among the three arms (p = 0.022), with a superiority for Arm C. At 24 months, the proportion of patients without relapse was 42% for Arm C vs. 23% for Arm A and 20% for Arm B. Patients in Arm A less frequently developed G3+ acute mucositis than their counterparts in Arm B or C (14.7% vs. 40.3% vs. 44%). Regarding the CT-related acute toxicity, apart from 1 case of fatal nephrotoxicity, only hematologic G3+ (Grade 3

  16. Vacuum electron acceleration by coherent dipole radiation

    International Nuclear Information System (INIS)

    Troha, A.L.; Van Meter, J.R.; Landahl, E.C.; Alvis, R.M.; Hartemann, F.V.; Troha, A.L.; Van Meter, J.R.; Landahl, E.C.; Alvis, R.M.; Li, K.; Luhmann, N.C. Jr.; Hartemann, F.V.; Unterberg, Z.A.; Kerman, A.K.

    1999-01-01

    The validity of the concept of laser-driven vacuum acceleration has been questioned, based on an extrapolation of the well-known Lawson-Woodward theorem, which stipulates that plane electromagnetic waves cannot accelerate charged particles in vacuum. To formally demonstrate that electrons can indeed be accelerated in vacuum by focusing or diffracting electromagnetic waves, the interaction between a point charge and coherent dipole radiation is studied in detail. The corresponding four-potential exactly satisfies both Maxwell's equations and the Lorentz gauge condition everywhere, and is analytically tractable. It is found that in the far-field region, where the field distribution closely approximates that of a plane wave, we recover the Lawson-Woodward result, while net acceleration is obtained in the near-field region. The scaling of the energy gain with wave-front curvature and wave amplitude is studied systematically. copyright 1999 The American Physical Society

  17. DART-bid: dose-differentiated accelerated radiation therapy, 1.8 Gy twice daily. High local control in early stage (I/II) non-small-cell lung cancer

    International Nuclear Information System (INIS)

    Zehentmayr, Franz; Wurstbauer, Karl; Deutschmann, Heinz; Sedlmayer, Felix; Fussl, Christoph; Kopp, Peter; Dagn, Karin; Fastner, Gerd; Porsch, Peter; Studnicka, Michael

    2015-01-01

    While surgery is considered standard of care for early stage (I/II), non-small-cell lung cancer (NSCLC), radiotherapy is a widely accepted alternative for medically unfit patients or those who refuse surgery. International guidelines recommend several treatment options, comprising stereotactic body radiation therapy (SBRT) for small tumors, conventional radiotherapy ≥ 60 Gy for larger sized especially centrally located lesions or continuous hyperfractionated accelerated RT (CHART). This study presents clinical outcome and toxicity for patients treated with a dose-differentiated accelerated schedule using 1.8 Gy bid (DART-bid). Between April 2002 and December 2010, 54 patients (median age 71 years, median Karnofsky performance score 70 %) were treated for early stage NSCLC. Total doses were applied according to tumor diameter: 73.8 Gy for 6 cm. The median follow-up was 28.5 months (range 2-108 months); actuarial local control (LC) at 2 and 3 years was 88 %, while regional control was 100 %. There were 10 patients (19 %) who died of the tumor, and 18 patients (33 %) died due to cardiovascular or pulmonary causes. A total of 11 patients (20 %) died intercurrently without evidence of progression or treatment-related toxicity at the last follow-up, while 15 patients (28 %) are alive. Acute esophagitis ≤ grade 2 occurred in 7 cases, 2 patients developed grade 2 chronic pulmonary fibrosis. DART-bid yields high LC without significant toxicity. For centrally located and/or large (> 5 cm) early stage tumors, where SBRT is not feasible, this method might serve as radiotherapeutic alternative to present treatment recommendations, with the need of confirmation in larger cohorts. (orig.) [de

  18. Radiation protection and dosimetry problems around medium energy accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovic, R; Pavlovic, S; Markovic, S [Inst. of Nuclear Sciences Vinca, Belgrade (Yugoslavia); Boreli, F [Fac. of Electrical Engineering, Belgrade (Yugoslavia)

    1996-12-31

    In the Institute of Nuclear Sciences `VINCA`, the Accelerator Installation `TESLA`, which is an ion accelerator facility consisting of an isochronous cyclotron `VINCY`, a heavy ion source, a D{sup -} / H{sup -} ion source, three low energy and five high energy experimental channels is now under construction. The Tesla Accelerator Installation should by the principal facility for basic and applied research in physics, chemistry, biology, and material science, as well as for production of radioisotopes, medical diagnostics and therapy with radioisotopes and accelerated particle beams. Some problems in defining radiation protection and safety programme, particularly problems in construction appropriate shielding barriers at the Accelerator Installation `TESLA` are discussed in this paper. (author) 1 fig., 9 refs.

  19. Concurrent hyperfractionated accelerated radiotherapy with 5-FU and once weekly cisplatin in locally advanced head and neck cancer. The 10-year results of a prospective phase II trial

    Energy Technology Data Exchange (ETDEWEB)

    Budach, V.; Boehmer, D.; Badakhshi, H.; Jahn, U.; Stromberger, C. [Campus Virchow Klinikum, Charite Universitaetsmedizin Berlin, Department for Radiooncology, Clinic for Radiooncology, Berlin (Germany); Becker, E.T. [Charite Universitaetsmedizin, Department of Otorhinolaryngology, Berlin (Germany); Wernecke, K.D. [Sostana Statistics GmbH, Charite Universitaetsmedizin Berlin, Berlin (Germany)

    2014-03-15

    In this study, the acute toxicity and long-term outcome of a hyperfractionated accelerated chemoradiation regimen with cisplatin/5-fluorouracil (5-FU) in patients with locally advanced squamous cell carcinomas of head and neck were evaluated. From 2000-2002, 38 patients with stage III (5.3 %) and stage IV (94.7 %) head and neck cancer were enrolled in a phase II study. Patients received hyperfractionated-accelerated radiotherapy with 72 Gy in 15 fractions of 2 Gy followed by 1.4 Gy twice daily with concurrent, continuous infusion 5-FU of 600 mg/m{sup 2} on days 1-5 and 6 cycles of weekly cisplatin (30 mg/m{sup 2}). Acute toxicities (CTCAEv2.0), locoregional control (LRC), metastases-free (MFS), and overall survival (OS) were analyzed and exploratively compared with the ARO 95-06 trial. Median follow-up was 11.4 years (95 % CI 8.6-14.2) and mean dose 71.6 Gy. Of the patients, 82 % had 6 (n = 15) or 5 (n = 16) cycles of cisplatin, 5 and 2 patients received 4 and 3 cycles, respectively. Grade 3 anemia, leukopenia, and thrombocytopenia were observed in 15.8, 15.8, and 2.6 %, respectively. Grade 3 mucositis in 50 %, grade 3 and 4 dysphagia in 55 and 13 %. The 2-, 5-, and 10-year LRC was 65, 53.6, and 48.2 %, the MFS was 77.5, 66.7, and 57.2 % and the OS 59.6, 29.2, and 15 %, respectively. Chemoradiation with 5-FU and cisplatin seems feasible and superior in terms of LRC and OS to the ARO 95-06C-HART arm at 2 years. However, this did not persist at the 5- and 10-year follow-ups. (orig.) [German] Untersuchung der Akuttoxizitaet und des Langzeitueberlebens einer hyperfraktioniert-akzelerierten simultanen Radiochemotherapie mit Cisplatin/5-Fluorouracil (5-FU) bei Patienten mit lokal fortgeschrittenen Kopf-Hals-Tumoren. Von 2000 bis 2002 wurden 38 Patienten mit Plattenepithelkarzinomen der Kopf-Hals-Region im Stadium III (5,3 %) und IV (94,7 %) eingeschlossen. Es erfolgte eine simultane hyperfraktionierte akzelerierte Radiochemotherapie mit 72 Gy in 15 Fraktionen a 2 Gy

  20. Pulsed electron accelerator for radiation technologies in the enviromental applications

    Science.gov (United States)

    Korenev, Sergey

    1997-05-01

    The project of pulsed electron accelerator for radiation technologies in the environmental applications is considered. An accelerator consists of high voltage generator with vacuum insulation and vacuum diode with plasma cathode on the basis discharge on the surface of dielectric of large dimensions. The main parameters of electron accelerators are following: kinetic energy 0.2 - 2.0 MeV, electron beam current 1 - 30 kA and pulse duration 1- 5 microseconds. The main applications of accelerator for decomposition of wastewaters are considered.

  1. Use of mobile robots for mapping radiation field around particle accelerators

    International Nuclear Information System (INIS)

    Sharma, S.; Agashe, V.; Pal, P.K.

    2011-01-01

    In Particle Accelerators, when the accelerated particles hit the target or inadvertently strike the wall, prompt and induced radiation is produced. It is necessary to monitor the resulting radiation field in order to reduce radiation exposure to operating personnel, as well as to locate points of leakage of the particle beam. This paper describes the development of mobile robots equipped with onboard radiation detectors for mapping such radiation fields. They include a user interface software running on a host computer to tele operate the robot, monitor radiation levels, and build and display a radiation map out of these data through interpolation. One such robot (ARMER-II), designed and developed by us in consultation with Radiation Safety Division (RSD), is a portable mobile robot for identifying locations with radiation levels higher than permissible limits. Its remote interface computes and guides the robot to move in a direction in which the increase in intensity of radiation is the steepest. Another mobile robot (ARMER-I) has a telescopic arm fitted with a light and small GM tube. This also can be controlled remotely, and is very useful in remote measurement of radiation from locations which are difficult to reach otherwise. Another version (ASHWA) has been successfully adapted by VECC, Kolkata, for gamma and neutron radiation profiling in the cyclotron vault area. We are presently working on the design and development of a four-wheel differentially driven mobile robot (RADMAPPER) with higher payload capacity for carrying radiation detectors like gamma camera and neutron dosimeters and positioning them at desired heights. With appropriate localization capability, this is going to be a very flexible mobile robot based system for radiation profiling around particle accelerators. The specification for this robot has been prepared in consultation with VECC for use in their cyclotron facilities. (author)

  2. Radiative processes for Rindler and accelerating observers and the stress-tensor detector

    International Nuclear Information System (INIS)

    Paola, R. De; Svaiter, N.F.

    1996-04-01

    It is considered a monopole detector interacting with a massive scalar field. Using the rotating wave approximation the radiative processes is discussed from the accelerated frame point of view. After this, it is obtained the Minkowski vacuum stress tensor measured by the accelerated observer using a non-gravitational stress sensor detector. Finally we analyse radiative processes of the monopole detector travelling in a world line that is inertial in the infinite past and has a constant proper acceleration in the infinite future. (author). 30 refs

  3. Accelerators: radiation safety and regulatory compliance

    International Nuclear Information System (INIS)

    Bandyopadhyay, Tapas

    2013-01-01

    Growth of accelerators, both positive ions and electron, is very high in India. This may be because of the wide acceptance of these machines in the industrial purposes, medical uses, material science studies, upcoming ADSS facility and many other reasons. Most of cases for societal uses, accelerators have to be installed in the dense public domain. Accelerators for basic research and development purposes to be installed may in public domain or in isolated site. These accelerators are to be classified into different categories in terms of regulatory compliance. Radiation shield design, HVAC system required to be in place with design so that the dose and effluent discharge in the public domain is within a limit considering different pathways. INDUS I and II at Indore, K-130 and K500 machine at VECC, Pelletron at TIFR, IUAC, BARC, EBC at Mumbai are in operation. Apart from this accelerators, a series of medical accelerators in operation and yet to be operational which are generally producing PET isotopes for the diagnosis purposes. VECC is aiming to operate 30 MeV proton machine with about 500 μA beam current for the production of PET, SPECT isotopes for diagnosis purposes and also therapeutic use in near future. Detail requirement in terms of choice of sites, source term estimation for achieving optimum shield thickness, ventilation system, site layout and planning , radioactive effluent handling both gaseous and liquid, decommission aspects will be discussed. (author)

  4. Effect of single dose, fractionated, and hyperfractionated trunk irradiation on weight gain, respiration frequency, and survival in rats

    International Nuclear Information System (INIS)

    Kimler, B.F.; Giri, P.G.S.; Giri, U.P.; Cox, G.G.

    1986-01-01

    It is concluded that, in this rat trunk irradiation model, fractionation of a single dose into two equal doses separated by 4-6 h produced a sparing effect of approx. 5Gy as measured by delay in weight gain; approx. 4Gy as measured by increased respiration frequency; and approx. 6Gy as measured by survival. Fractionation into daily doses or hyperfractionation into twice-daily doses permitted an approximate doubling of the dose required for the same suppression of weight gain. For the respiration rates and survival endpoints, fractionation or hyperfractionation produced an even greater sparing effect since there was no increase in the respiration frequency at twice the doses that would produce changes if delivered within a few hours; and since essentially no lethality was observed at twice the doses that would kill 70%-100% of animals if delivered in one day. (UK)

  5. New generation of compact electron accelerators for radiation technologies

    International Nuclear Information System (INIS)

    Auslender, V.L.; Balakin, V.E.; Kraynov, G.S.

    1995-01-01

    Compact electron accelerators with energy range 0.25-1.0 MeV and beam power up to 32 kw are described. The feeding high voltage is formed by converter (working frequency 20 khz), coreless step-up transformer and a set of rectifying sections. The rectifying multiplier circuit used in rectifying sections permits to reach voltage gradient along accelerator's axis up to 14 kV/cm. The accelerators with vertical and horizontal position are described. The accelerators can be produced together with local radiation shielding and various underbeam transportation systems for irradiation of different products. Such version can be installed in any room facing general requirements for electric equipment

  6. A system for monitoring the radiation effects of a proton linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Skorkin, V. M., E-mail: skorkin@inr.ru; Belyanski, K. L.; Skorkin, A. V. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

    2016-12-15

    The system for real-time monitoring of radioactivity of a high-current proton linear accelerator detects secondary neutron emission from proton beam losses in transport channels and measures the activity of radionuclides in gas and aerosol emissions and the radiation background in the environment affected by a linear accelerator. The data provided by gamma, beta, and neutron detectors are transferred over a computer network to the central server. The system allows one to monitor proton beam losses, the activity of gas and aerosol emissions, and the radiation emission level of a linear accelerator in operation.

  7. Quality control methods for linear accelerator radiation and mechanical axes alignment.

    Science.gov (United States)

    Létourneau, Daniel; Keller, Harald; Becker, Nathan; Amin, Md Nurul; Norrlinger, Bernhard; Jaffray, David A

    2018-06-01

    The delivery accuracy of highly conformal dose distributions generated using intensity modulation and collimator, gantry, and couch degrees of freedom is directly affected by the quality of the alignment between the radiation beam and the mechanical axes of a linear accelerator. For this purpose, quality control (QC) guidelines recommend a tolerance of ±1 mm for the coincidence of the radiation and mechanical isocenters. Traditional QC methods for assessment of radiation and mechanical axes alignment (based on pointer alignment) are time consuming and complex tasks that provide limited accuracy. In this work, an automated test suite based on an analytical model of the linear accelerator motions was developed to streamline the QC of radiation and mechanical axes alignment. The proposed method used the automated analysis of megavoltage images of two simple task-specific phantoms acquired at different linear accelerator settings to determine the coincidence of the radiation and mechanical isocenters. The sensitivity and accuracy of the test suite were validated by introducing actual misalignments on a linear accelerator between the radiation axis and the mechanical axes using both beam steering and mechanical adjustments of the gantry and couch. The validation demonstrated that the new QC method can detect sub-millimeter misalignment between the radiation axis and the three mechanical axes of rotation. A displacement of the radiation source of 0.2 mm using beam steering parameters was easily detectable with the proposed collimator rotation axis test. Mechanical misalignments of the gantry and couch rotation axes of the same magnitude (0.2 mm) were also detectable using the new gantry and couch rotation axis tests. For the couch rotation axis, the phantom and test design allow detection of both translational and tilt misalignments with the radiation beam axis. For the collimator rotation axis, the test can isolate the misalignment between the beam radiation axis

  8. Report of promotion expert commission for radiation application on 'Promotion of accelerator application study'

    International Nuclear Information System (INIS)

    1997-01-01

    This is a report published on June, 1996, by promotion expert commission for radiation application of the Atomic Energy Commission. Japanese research and development in the fields of forming and application techniques of radiation beams using accelerator is at comparatively high level in the world, and it seems to be important for Japan not only to maintain these research and development level but also to contribute to creation of worldwide intelligent welfare due to scientific technology. In this report, some investigations are conducted on present state and future view of the radiation application study using accelerator, accelerator facility necessary to promote such application study and a procedure to execute its smooth application. However, objects of the study are not limited only for physical study on elementary particle and atomic nucleus, but expanded to photon, electron, positron, muon, proton, neutron, various inonic beams and RI beams for radiations, which are widely applied to industries such as materials science, material engineering, bio-and life-science, medical science, technical engineering, and so forth, and which will be expected for large contribution to development of these industries. The following items are discussed here; 1) present state and future view of radiation application study using accelerator, 2) Accelerator to be prepared and its executing method, and 3) Promotion method of the accelerator application study. (G.K.)

  9. Accelerator simulation and theoretical modelling of radiation effects (SMoRE)

    CERN Document Server

    2018-01-01

    This publication summarizes the findings and conclusions of the IAEA coordinated research project (CRP) on accelerator simulation and theoretical modelling of radiation effects, aimed at supporting Member States in the development of advanced radiation-resistant structural materials for implementation in innovative nuclear systems. This aim can be achieved through enhancement of both experimental neutron-emulation capabilities of ion accelerators and improvement of the predictive efficiency of theoretical models and computer codes. This dual approach is challenging but necessary, because outputs of accelerator simulation experiments need adequate theoretical interpretation, and theoretical models and codes need high dose experimental data for their verification. Both ion irradiation investigations and computer modelling have been the specific subjects of the CRP, and the results of these studies are presented in this publication which also includes state-ofthe- art reviews of four major aspects of the project...

  10. Standalone, battery powered radiation monitors for accelerator electronics

    CERN Document Server

    Wijnands, T; Spiezia, G

    2009-01-01

    A technical description of the design of a new type of radiation monitors is given. The key point in the design is the low power consumption inferior to 17 mW in radiation sensing mode and inferior to 0.3 mW in standby mode. The radiation monitors can operate without any external power or signal cabling and measure and store radiation data for a maximum period of 800 days. To read the radiation data, a standard PC can be connected via a USB interface to the device at any time. Only a few seconds are required to read out a single monitor. This makes it possible to survey a large network of monitoring devices in a short period of time, for example during a stop of the accelerator.

  11. Radiation Fields in High Energy Accelerators and their impact on Single Event Effects

    CERN Document Server

    García Alía, Rubén; Wrobel, Frédéric; Brugger, Markus

    Including calculation models and measurements for a variety of electronic components and their concerned radiation environments, this thesis describes the complex radiation field present in the surrounding of a high-energy hadron accelerator and assesses the risks related to it in terms of Single Event Effects (SEE). It is shown that this poses not only a serious threat to the respective operation of modern accelerators but also highlights the impact on other high-energy radiation environments such as those for ground and avionics applications. Different LHC-like radiation environments are described in terms of their hadron composition and energy spectra. They are compared with other environments relevant for electronic component operation such as the ground-level, avionics or proton belt. The main characteristic of the high-energy accelerator radiation field is its mixed nature, both in terms of hadron types and energy interval. The threat to electronics ranges from neutrons of thermal energies to GeV hadron...

  12. Complex of electrostatic accelerators for simulation and diagnostics of radiation damage

    International Nuclear Information System (INIS)

    Antuf'ev, Yu.P.; Belyaev, V.Kh.; Vergunov, A.D.

    1983-01-01

    The installation for simulation and diagnostics of radiation damage of materials is described. The installation consists of two electrostatic accelerators of vertical type for 5 MV and horizontal type for 800 kV. The accelerating complex ensures accelerated ion beam production in the independent operation regime as well as in the two beams target simultaneous irradiation regime, energy range of accelerated single-charged ions is 80 keV ... 5 MeV, homogeneity is better than +-0.05%. Oilless vacuum pumping out system is realized at the accelerating complex

  13. Operation and maintenance manual of the accelerator installed in the facility of radiation standards

    International Nuclear Information System (INIS)

    Fujii, Katsutoshi; Kawasaki, Katsuya; Kowatari, Munehiko; Tanimura, Yoshihiko; Kajimoto, Yoichi; Shimizu, Shigeru

    2006-08-01

    4MV Van de Graff accelerator was installed in the Facility of Radiation Standards (FRS) in June 2000, and monoenergetic neutron calibration fields and high energy γ-ray calibration fields have been developed. The calibration fields are provided for R and D on dosimetry, and for the calibration and type-test of radiation protection instruments. This article describes the operational procedure, the maintenance work and the operation of the related apparatuses of the accelerator. This article focuses on the sufficient safety and radiation control for the operators, the maintenance performance of the accelerator, and on the prevention of the malfunction due to the mistakes of the operators. This article targets the unexperienced engineers in charge of operation and maintenance of the accelerator. (author)

  14. Intraoperative radiation therapy using mobile electron linear accelerators: Report of AAPM Radiation Therapy Committee Task Group No. 72

    International Nuclear Information System (INIS)

    Sam Beddar, A.; Biggs, Peter J.; Chang Sha; Ezzell, Gary A.; Faddegon, Bruce A.; Hensley, Frank W.; Mills, Michael D.

    2006-01-01

    Intraoperative radiation therapy (IORT) has been customarily performed either in a shielded operating suite located in the operating room (OR) or in a shielded treatment room located within the Department of Radiation Oncology. In both cases, this cancer treatment modality uses stationary linear accelerators. With the development of new technology, mobile linear accelerators have recently become available for IORT. Mobility offers flexibility in treatment location and is leading to a renewed interest in IORT. These mobile accelerator units, which can be transported any day of use to almost any location within a hospital setting, are assembled in a nondedicated environment and used to deliver IORT. Numerous aspects of the design of these new units differ from that of conventional linear accelerators. The scope of this Task Group (TG-72) will focus on items that particularly apply to mobile IORT electron systems. More specifically, the charges to this Task Group are to (i) identify the key differences between stationary and mobile electron linear accelerators used for IORT (ii) describe and recommend the implementation of an IORT program within the OR environment, (iii) present and discuss radiation protection issues and consequences of working within a nondedicated radiotherapy environment, (iv) describe and recommend the acceptance and machine commissioning of items that are specific to mobile electron linear accelerators, and (v) design and recommend an efficient quality assurance program for mobile systems

  15. Primer on theory and operation of linear accelerators in radiation therapy

    International Nuclear Information System (INIS)

    Karzmark, C.J.; Morton, R.J.

    1981-12-01

    This primer is part of an educational package that also includes a series of 3 videotapes entitled Theory and Operation of Linear Accelerators in Radiation Therapy, Parts I, II, and III. This publication provides an overview of the components of the linear accelerator and how they function and interrelate. The auxiliary systems necessary to maintain the operation of the linear accelerator are also described

  16. Accelerated thermal and radiative ageing of hydrogenated NBR for DRC

    International Nuclear Information System (INIS)

    Mares, G.; Notingher, P.

    1996-01-01

    The accelerated thermal and gamma radiation ageing of HNBR carbon black-T80 has been studied by measuring the residual deformation under constant deflection -- DRC, in air, using a relevant equation for the relaxation phenomena. The residual deformation under constant deflection during the process of accelerated ageing is increasing but the structure of polymer answers in the proper manner to the mechanical stress. The degradation equations were obtained, using Alfrey model for the relaxation polymer subject to compression and an Arrhenius dependence for the chemical reaction rate. The inverted relaxation time for the thermal degradation is depending on the chemical reaction rate and the dose rate of gamma radiation

  17. Plasma acceleration by means of microwave radiation pressure

    International Nuclear Information System (INIS)

    Fukumura, Takashi; Takamoto, Teruo

    1977-01-01

    In the electric discharge of gas with microwaves, intense reflection waves occur simultaneously with the discharge, so the plasma ionized and formed by the microwaves is accelerated due to large radiation pressure. The basic experiment made, aiming at plasma gun, is described. In the gas electric discharge, the plasma flow velocity proportional to the reflected power is obtained. For 550 W microwave input power, the plasma velocity of 1 x 10 4 m/s was obtained. The accelerated plasma is bunched; its front as mass travels, recombines and disappears. (Mori, K.)

  18. Radiation Safety of Accelerator Facility with Regard to Regulation

    International Nuclear Information System (INIS)

    Dedi Sunaryadi; Gloria Doloresa

    2003-01-01

    The radiation safety of accelerator facility and the status of the facilities according to licensee in Indonesia as well as lesson learned from the accidents are described. The atomic energy Act No. 10 of 1997 enacted by the Government of Indonesia which is implemented in Radiation Safety Government Regulation No. 63 and 64 as well as practice-specific model regulation for licensing request are discussed. (author)

  19. Cherenkov Radiation Control via Self-accelerating Wave-packets.

    Science.gov (United States)

    Hu, Yi; Li, Zhili; Wetzel, Benjamin; Morandotti, Roberto; Chen, Zhigang; Xu, Jingjun

    2017-08-18

    Cherenkov radiation is a ubiquitous phenomenon in nature. It describes electromagnetic radiation from a charged particle moving in a medium with a uniform velocity larger than the phase velocity of light in the same medium. Such a picture is typically adopted in the investigation of traditional Cherenkov radiation as well as its counterparts in different branches of physics, including nonlinear optics, spintronics and plasmonics. In these cases, the radiation emitted spreads along a "cone", making it impractical for most applications. Here, we employ a self-accelerating optical pump wave-packet to demonstrate controlled shaping of one type of generalized Cherenkov radiation - dispersive waves in optical fibers. We show that, by tuning the parameters of the wave-packet, the emitted waves can be judiciously compressed and focused at desired locations, paving the way to such control in any physical system.

  20. The radiation field measurement and analysis outside the shielding of A 10 MeV electron irradiation accelerator

    Science.gov (United States)

    Shang, Jing; Li, Juexin; Xu, Bing; Li, Yuxiong

    2011-10-01

    Electron accelerators are employed widely for diverse purposes in the irradiation-processing industry, from sterilizing medical products to treating gemstones. Because accelerators offer high efficiency, high power, and require little preventative maintenance, they are becoming more and more popular than using the 60Co isotope approach. However, the electron accelerator exposes potential radiation hazards. To protect workers and the public from exposure to radiation, the radiation field around the electronic accelerator must be assessed, especially that outside the shielding. Thus, we measured the radiation dose at different positions outside the shielding of a 10-MeV electron accelerator using a new data-acquisition unit named Mini-DDL (Mini-Digital Data Logging). The measurements accurately reflect the accelerator's radiation status. In this paper, we present our findings, results and compare them with our theoretical calculations. We conclude that the measurements taken outside the irradiation hall are consistent with the findings from our calculations, except in the maze outside the door of the accelerator room. We discuss the reason for this discrepancy.

  1. The radiation field measurement and analysis outside the shielding of A 10 MeV electron irradiation accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Shang Jing [National Synchrotron Radiation Lab, University of Science and Technology of China (China); Li Juexin, E-mail: juexin@ustc.edu.cn [National Synchrotron Radiation Lab, University of Science and Technology of China (China); Xu Bing; Li Yuxiong [National Synchrotron Radiation Lab, University of Science and Technology of China (China)

    2011-10-01

    Electron accelerators are employed widely for diverse purposes in the irradiation-processing industry, from sterilizing medical products to treating gemstones. Because accelerators offer high efficiency, high power, and require little preventative maintenance, they are becoming more and more popular than using the {sup 60}Co isotope approach. However, the electron accelerator exposes potential radiation hazards. To protect workers and the public from exposure to radiation, the radiation field around the electronic accelerator must be assessed, especially that outside the shielding. Thus, we measured the radiation dose at different positions outside the shielding of a 10-MeV electron accelerator using a new data-acquisition unit named Mini-DDL (Mini-Digital Data Logging). The measurements accurately reflect the accelerator's radiation status. In this paper, we present our findings, results and compare them with our theoretical calculations. We conclude that the measurements taken outside the irradiation hall are consistent with the findings from our calculations, except in the maze outside the door of the accelerator room. We discuss the reason for this discrepancy.

  2. Investigation of advanced propulsion technologies: The RAM accelerator and the flowing gas radiation heater

    Science.gov (United States)

    Bruckner, A. P.; Knowlen, C.; Mattick, A. T.; Hertzberg, A.

    1992-01-01

    The two principal areas of advanced propulsion investigated are the ram accelerator and the flowing gas radiation heater. The concept of the ram accelerator is presented as a hypervelocity launcher for large-scale aeroballistic range applications in hypersonics and aerothermodynamics research. The ram accelerator is an in-bore ramjet device in which a projectile shaped like the centerbody of a supersonic ramjet is propelled in a stationary tube filled with a tailored combustible gas mixture. Combustion on and behind the projectile generates thrust which accelerates it to very high velocities. The acceleration can be tailored for the 'soft launch' of instrumented models. The distinctive reacting flow phenomena that have been observed in the ram accelerator are relevant to the aerothermodynamic processes in airbreathing hypersonic propulsion systems and are useful for validating sophisticated CFD codes. The recently demonstrated scalability of the device and the ability to control the rate of acceleration offer unique opportunities for the use of the ram accelerator as a large-scale hypersonic ground test facility. The flowing gas radiation receiver is a novel concept for using solar energy to heat a working fluid for space power or propulsion. Focused solar radiation is absorbed directly in a working gas, rather than by heat transfer through a solid surface. Previous theoretical analysis had demonstrated that radiation trapping reduces energy loss compared to that of blackbody receivers, and enables higher efficiencies and higher peak temperatures. An experiment was carried out to measure the temperature profile of an infrared-active gas and demonstrate the effect of radiation trapping. The success of this effort validates analytical models of heat transfer in this receiver, and confirms the potential of this approach for achieving high efficiency space power and propulsion.

  3. Hyperfractionated accelerated radiotherapy with concomitant integrated boost of 70-75 Gy in 5 weeks for advanced head and neck cancer. A phase I dose escalation study

    Energy Technology Data Exchange (ETDEWEB)

    Cvek, J.; Skacelikova, E.; Otahal, B.; Halamka, M.; Feltl, D. [University Hospital Ostrava (Czech Republic). Dept. of Oncology; Kubes, J. [University Hospital Bulovka, Prague (Czech Republic). Dept. of Radiation Oncology; Kominek, P. [University Hospital Ostrava (Czech Republic). Dept. of Otolaryngology

    2012-08-15

    Background and purpose: The present study was performed to evaluate the feasibility of a new, 5-week regimen of 70-75 Gy hyperfractionated accelerated radiotherapy with concomitant integrated boost (HARTCIB) for locally advanced, inoperable head and neck cancer. Methods and materials: A total of 39 patients with very advanced, stage IV nonmetastatic head and neck squamous cell carcinoma (median gross tumor volume 72 ml) were included in this phase I dose escalation study. A total of 50 fractions intensity-modulated radiotherapy (IMRT) were administered twice daily over 5 weeks. Prescribed total dose/dose per fraction for planning target volume (PTV{sub tumor}) were 70 Gy in 1.4 Gy fractions, 72.5 Gy in 1.45 Gy fractions, and 75 Gy in 1.5 Gy fractions for 10, 13, and 16 patients, respectively. Uninvolved lymphatic nodes (PTV{sub uninvolved}) were irradiated with 55 Gy in 1.1 Gy fractions using the concomitant integrated boost. Results: Acute toxicity was evaluated according to the RTOG/EORTC scale; the incidence of grade 3 mucositis was 51% in the oral cavity/pharynx and 0% in skin and the recovery time was {<=} 9 weeks for all patients. Late toxicity was evaluated in patients in complete remission according to the RTOG/EORTC scale. No grade 3/4 late toxicity was observed. The 1-year locoregional progression-free survival was 50% and overall survival was 55%. Conclusion: HARTCIB (75 Gy in 5 weeks) is feasible for patients deemed unsuitable for chemoradiation. Acute toxicity was lower than predicted from radiobiological models; duration of dysphagia and confluent mucositis were particularly short. Better conformity of radiotherapy allows the use of more intensive altered fractionation schedules compared with older studies. These results suggest that further dose escalation might be possible when highly conformal techniques (e.g., stereotactic radiotherapy) are used.

  4. Electron acceleration and radiation signatures in loop coronal transients

    Science.gov (United States)

    Vlahos, L.; Gergely, T. E.; Papadopoulos, K.

    1982-01-01

    It is proposed that in loop coronal transients an erupting loop moves away from the solar surface, with a velocity exceeding the local Alfven speed, pushing against the overlying magnetic fields and driving a shock in the front of the moving part of the loop. Lower hybrid waves are excited at the shock front and propagate radially toward the center of the loop with phase velocity along the magnetic field that exceeds the thermal velocity. The lower hybrid waves stochastically accelerate the tail of the electron distribution inside the loop. The manner in which the accelerated electrons are trapped in the moving loop are discussed, and their radiation signature is estimated. It is suggested that plasma radiation can explain the power observed in stationary and moving type IV bursts.

  5. Engineered and Administrative Safety Systems for the Control of Prompt Radiation Hazards at Accelerator Facilities

    International Nuclear Information System (INIS)

    Liu, James C.; SLAC; Vylet, Vashek; Walker, Lawrence S.

    2007-01-01

    The ANSI N43.1 Standard, currently in revision (ANSI 2007), sets forth the requirements for accelerator facilities to provide adequate protection for the workers, the public and the environment from the hazards of ionizing radiation produced during and from accelerator operations. The Standard also recommends good practices that, when followed, provide a level of radiation protection consistent with those established for the accelerator communities. The N43.1 Standard is suitable for all accelerator facilities (using electron, positron, proton, or ion particle beams) capable of producing radiation, subject to federal or state regulations. The requirements (see word 'shall') and recommended practices (see word 'should') are prescribed in a graded approach that are commensurate with the complexity and hazard levels of the accelerator facility. Chapters 4, 5 and 6 of the N43.1 Standard address specially the Radiation Safety System (RSS), both engineered and administrative systems, to mitigate and control the prompt radiation hazards from accelerator operations. The RSS includes the Access Control System (ACS) and Radiation Control System (RCS). The main requirements and recommendations of the N43.1 Standard regarding the management, technical and operational aspects of the RSS are described and condensed in this report. Clearly some aspects of the RSS policies and practices at different facilities may differ in order to meet the practical needs for field implementation. A previous report (Liu et al. 2001a), which reviews and summarizes the RSS at five North American high-energy accelerator facilities, as well as the RSS references for the 5 labs (Drozdoff 2001; Gallegos 1996; Ipe and Liu 1992; Liu 1999; Liu 2001b; Rokni 1996; TJNAF 1994; Yotam et al. 1991), can be consulted for the actual RSS implementation at various laboratories. A comprehensive report describing the RSS at the Stanford Linear Accelerator Center (SLAC 2006) can also serve as a reference

  6. Radiation testing of thick-wall objects using a linear accelerator or Co-60

    International Nuclear Information System (INIS)

    Depending on the energy required, a 60 Co source or various types of betatrons and linear accelerators may be used for radiation testing of thick-walled metal parts. While 60 Co sources are easily transported, accelerators are not, but a transportable linear accelerator is described

  7. Predictive value of the flow cytometric PCNA - assay (proliferating cell nuclear antigen) in head and neck tumors after accelerated-hyperfractionated radiochemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wenz, F; Lohr, F; Rudat, V; Dietz, A; Flentje, M; Wannenmacher, M

    1995-07-01

    Purpose/Objective: Proliferation of surviving tumor cells during fractionated radiotherapy may limit tumor control, especially in rapidly proliferating tumors. It has been widely accepted, that this may play a major role in head and neck tumors. Several methods for the assessment of tumor proliferation have been developed, however, most of them are either laborious, invasive or potentially toxic. Today, the gold standard is the flow cytometric BrdUrd assay. We present a flow cytometric method for detection of PCNA, which is an intranuclear proliferation associated protein, in solid human head and neck tumors and how these data correlate with outcome. Materials and Methods: Pretherapeutic biopsies of 20 inoperable patients with squamous cell carcinoma of the head and neck (T3-4N2M0) were examined. The tissue was disaggregated with pepsin/HCl, antibody staining was performed using the clone PC10. Biparametric flow cytometry was performed after a FITC conjugated secondary antibody and propidiumjodine staining was applied. The PCNA-index (i.e. percentage PCNA-positive cells), the DNA-index and the S-phase fraction (SPF, euploid tumors only) were determined. The therapy consisted of combined accelerated-hyperfractionated radiochemotherapy (66 Gy in 5 wks, concomittant boost of 1.6 Gy/d in wks 4+5, Carboplatin in wks 1+5). The median follow-up time was 14 mths (5 - 28), the clinical partners (V.R., A.D.) were 'blinded' towards the PCNA-values. Results: 13 patients suffered from disease progession and 11 died. The actuarial median survival and disease free survival (DFS) were 14.4 and 10.7 mths, respectively. The PCNA-values ranged from 3.2 to 70% (median 9%), there were 7 aneuploid and 13 euploid tumors. SFP in the euploid tumors ranged from 4 to 14.5% (median 10.5%). Neither SFP nor ploidy had a significant influence on the outcome. The patients were divided according to their PCNA-value in higher (n=10) and lower (n=10) than the median. The survival and DFS were 13

  8. Incidence of interstitial pneumonia after hyperfractionated total body irradiation before autologous bone marrow/stem cell transplantation

    International Nuclear Information System (INIS)

    Lohr, F.; Schraube, P.; Wenz, F.; Flentje, M.; Kalle, K. von; Haas, R.; Hunstein, W.; Wannenmacher, M.

    1995-01-01

    Purpose/Objectives Interstitial pneumonia (IP) is a severe complication after allogenic bone marrow transplantation (BMT) with incidence rates between 10 % and 40 % in different series. It is a polyetiologic disease that occurs depending on age, graft vs. host disease (GvHD), CMV-status, total body irradiation (TBI) and immunosuppressive therapy after BMT. The effects of fractionation and dose rate are not entirely clear. This study evaluates the incidence of lethal IP after hyperfractionated TBI for autologous BMT or stem cell transplantation. Materials and Methods Between 1982 and 1992, 182 patients (60 % male, 40 % female) were treated with hyperfractionated total body irradiation (TBI) before autologous bone marrow transplantation. Main indications were leukemias and lymphomas (53 % AML, 21 % ALL, 22 % NHL, 4 % others) Median age was 30 ys (15 - 55 ys). A total dose of 14.4 Gy was applied using lung blocks (12 fractions of 1.2 Gy in 4 days, dose rate 7-18 cGy/min, lung dose 9 - 9.5 Gy). TBI was followed by cyclophosphamide (200 mg/kg). 72 % were treated with bone marrow transplantation, 28 % were treated with stem cell transplantation. Interstitial pneumonia was diagnosed clinically, radiologically and by autopsy. Results 4 patients died most likely of interstitial pneumonia. For another 12 patients interstitial pneumonia was not the most likely cause of death but could not be excluded. Thus, the incidence of lethal IP was at least 2.2 % but certainly below 8.8 %. Conclusion Lethal interstitial pneumonia is a rare complication after total body irradiation before autologous bone marrow transplantation in this large, homogeously treated series. In the autologous setting, total doses of 14.4 Gy can be applied with a low risk for developing interstitial pneumonia if hyperfractionation and lung blocks are used. This falls in line with data from series with identical twins or t-cell depleted marrow and smaller, less homogeneous autologous transplant studies. Thus

  9. Bookshelf (H. Wade Patterson and Ralph H. Thomas, editors; 'A History of Accelerator Radiation Protection')

    Energy Technology Data Exchange (ETDEWEB)

    Hoefert, Manfred

    1994-10-15

    This book is a collection of contributions on the history of accelerator radiation protection by people who have worked or still work in this field at particle accelerators around the world. The radiation environment of these machines is the most complex man-made radiation field one could face. In fact, protection efforts must cover a large spectrum of particles and energies ranging from thermal, in the case of neutrons, to the primary energy of the accelerator. Therefore the correct assessment of the exposure risk for people working in such stray radiation fields is a theme of many of the articles. The editors deliberately refrained from guiding the authors' styles, so the book contains a collection of papers ranging from articles with literary ambitions to dry accounts on radiation protection efforts around a particular accelerator complex. Although this retains the originality of the individual contributions, one would have liked to see a somewhat more anecdotal/historical approach rather than concentrating on scientific depth. Considering the types and energies of the radiations involved another outstanding and reoccurring issue is the question of accelerator shielding, where correct answers require considerable experimental and calculational efforts. While no shielding (it has happened!) proved to be bad, overshielding never turned out to be a problem in view of the increase in intensities that older machines have gone on to achieve. Is this a book only for the few radiation protection specialists working in an accelerator environment? Not necessarily. The physics aspects of radiation protection (generally called health physics in the US) is always evident and makes many articles interesting to read even for the non-specialist. The editors' epilogue proudly claims that most health physicists working around accelerators regard themselves as the elite of their profession. On the other hand the statement made by one eminent colleague - ''that health physics

  10. Open cell conducting foams for high synchrotron radiation accelerators

    Directory of Open Access Journals (Sweden)

    S. Petracca

    2014-08-01

    Full Text Available The possible use of open cell conductive foams in high synchrotron radiation particle accelerators is considered. Available materials and modeling tools are reviewed, potential pros and cons are discussed, and preliminary conclusions are drawn.

  11. High power radiation guiding systems for laser driven accelerators

    International Nuclear Information System (INIS)

    Cutolo, A.

    1985-01-01

    This paper reviews the main problems encountered in the design of an optical system for transmitting high fluence radiation in a laser driven accelerator. Particular attention is devoted to the analysis of mirror and waveguide systems. (orig.)

  12. Application of the personnel photographic monitoring method to determine equivalent radiation dose beyond proton accelerator shielding

    International Nuclear Information System (INIS)

    Gel'fand, E.K.; Komochkov, M.M.; Man'ko, B.V.; Salatskaya, M.I.; Sychev, B.S.

    1980-01-01

    Calculations of regularities to form radiation dose beyond proton accelerator shielding are carried out. Numerical data on photographic monitoring dosemeter in radiation fields investigated are obtained. It was shown how to determine the total equivalent dose of radiation fields beyond proton accelerator shielding by means of the photographic monitoring method by introduction into the procedure of considering nuclear emulsions of division of particle tracks into the black and grey ones. A comparison of experimental and calculational data has shown the applicability of the used calculation method for modelling dose radiation characteristics beyond proton accelerator shielding [ru

  13. Exclusive radiation therapy for locally advanced laryngeal carcinoma

    International Nuclear Information System (INIS)

    Antognoni, P.; Bossi, A.; Molteni, M.; Richetti, A.; Tordiglione, M.

    1990-01-01

    The authors analyse a retrospective series of 90 consecutive patients (pts) affected with locally advanced laryngeal carcinoma (T3-4, N0-3 - TNM, UICC 1978) who were radically irradiated from November 1979 to December 1986 at the Radiotherapy Department of the General Hospital of Varese. All the patients were treated with 60 Co and two opposed parallel lateral fields and progressive shrinkage: 66 conventional fractionation (2 Gy once a day, 5 times a week), 24 with an accelerated hyperfractionated regimen (1.5 Gy twice a day, 5 times a week). The median total dose delivered to the tumor and clinically involved nodes was 64 Gy (1678 reu, CRE). Median follow-up was 21 months (range: 3-113). The 5-year overall survival (Kaplan-Meier) was 40.5%. The 5-year disease-free survival, for 47 patients in complete remission at the end of radiotherapy, was 51.9% after irradiation alone and 56.7% with salvage surgery. There were no statistically significant differences in survival according to local spread (T3 vs T4), nodal status (N0 vs N1-3) and dose fractionation regimen (conventional vs accelerated hyper-fractionated). Isoeffect (CRE) values above 1751 reu obtained a 3-year loco-regional control rate was 33.3%. Relevant late sequelae were not observed. Our findings suggest that primary radiotherapy with salvage surgery in reserve could be considered as an effective choice for locally advanced laryngeal carcinoma, at least in selected groups of patients

  14. The impact of radiation dose and fractionation on the risk factor of radiation pneumonitis on four radiation therapy oncology group (RTOG) lung cancer trials

    International Nuclear Information System (INIS)

    Roach, Mack; Pajak, Thomas F; Byhardt, Roger; Graham, Mary L; Asbell, Sucha O; Russell, Anthony H; Fu, Karen K; Urtasun, Raul C; Herskovic, Arnold M; Cox, James D

    1997-01-01

    Purpose/Objective: To assess the relationship between total dose of radiation delivered, the fractionation scheme used, age, and Karnofsky Performance Status (KPS) on the risk of moderate to severe (≥ Grade 2) radiation pneumonitis in patients treated with radiotherapy alone for lung cancer on four RTOG Trials. Materials and Methods: Between February of 1984 and April of 1989, 1701 patients with clinically localized (I-IIIb) lung cancer were entered on clinical trials employing radiotherapy alone. Twelve hundred and forty-seven patients were entered on RTOG 8311 or 8407 (phase I/II trials) and 454 patients were entered on RTOG 8321 or 8403 (phase III trials). RTOG 8403 and 8321 patients received once-a-day irradiation to 60 Gy. Patients treated on RTOG 8407 were treated with a concomitant boost technique in a non-randomized fashion to 64.8, 69.6, 74.4 or 79.2 Gy. Patients treated on RTOG 8407 were treated with a concomitant boost technique in a non-randomized fashion to 63 Gy or 70.2 Gy. All patients were assessed for the incidence of Grade 2-5, radiation pneumonitis. One hundred and seven (6%) of patients were either ineligible or canceled (n=60), or were excluded because of incomplete data (n=47). The factors evaluated included total dose of radiation, the fractionation scheme, age and pre-treatment KPS. Patients treated to doses ≥ 72 Gy were considered to have received high doses (72.0 - 81.6 Gy), while the remaining patients treated to doses < 72 Gy (57.6 - 71.9 Gy) were considered to have received standard dose radiation. For the this analysis, information regarding field size and baseline pulmonary function was not available. Results: Age, sex, stage distribution, and the percentage of patients with a KPS ≥90 were similar among the patients treated on these four studies. Patients receiving hyperfractionated radiotherapy to doses ≥ 72 Gy experienced a higher incidence of radiation pneumonitis ≥ Grade 2, than patients treated with standard doses < 72

  15. Quality of life assessment in advanced non-small-cell lung cancer patients undergoing an accelerated radiotherapy regimen: report of ECOG study 4593

    International Nuclear Information System (INIS)

    Auchter, Richard M.; Scholtens, Denise; Adak, Sudeshna; Wagner, Henry; Cella, David F.; Mehta, Minesh P.

    2001-01-01

    Purpose: To prospectively evaluate the quality of life (QOL) before, at completion, and after therapy for patients receiving an accelerated fractionation schedule of radiotherapy for advanced, unresectable non-small-cell lung cancer in a Phase II multi-institutional trial. Methods and Materials: The Functional Assessment of Cancer Therapy-Lung (FACT-L) patient questionnaire was used to score the QOL in patients enrolled in the Eastern Cooperative Oncology Group Phase II trial (ECOG 4593) of hyperfractionated accelerated radiotherapy in non-small-cell lung cancer. Radiotherapy (total dose 57.6 Gy in 36 fractions) was delivered during 15 days, with three radiation fractions given each treatment day. The protocol was activated in 1993, and 30 patients had accrued by November 1995. The FACT-L questionnaire was administered at study entry (baseline), on the last day of radiotherapy (assessment 2), and 4 weeks after therapy (assessment 3). The FACT-L includes scores for physical, functional, emotional, and social well-being (33 items), and a subscale of lung cancer symptoms (10 additional items). The summation of the physical, functional, and lung cancer symptom subscales (21 items) constitutes the Trial Outcome Index (TOI), considered the most clinically relevant outcome measure in lung cancer treatment trials. Results: The FACT-L completion rates at the designated study time points were as follows: baseline, 30 of 30 (100%); assessment 2, 29 (97%) of 30; and assessment 3, 24 (80%) of 30. At treatment completion, statistically significant declines in QOL scores were noted, compared with baseline for physical and functional well-being. Emotional well-being scores improved at both assessment 2 and assessment 3. The physical and functional scores returned approximately to baseline values at assessment 3. The change in TOI score was evaluated as a function of the clinical response to treatment, toxicity grade, and survival; no clear association was noted. A trend for the

  16. External radiation exposure control system in accelerator facilities

    International Nuclear Information System (INIS)

    Ogawa, Tatsuhiko; Iimoto, Takeshi; Kosako, Toshiso

    2011-01-01

    The external exposure control systems in KEK and CERN are discussed to find out good practices and unreasonableness of radiation control in accelerator facilities, which plays an important role in optimizing national and/or site specific radiological regulations, referring to relevant ICRP publications. Personal dose limits and radiation area classifications were analyzed and their reasonableness were explored. Good example of supervised areas, area classification based on realistic assumptions on working time etc are found. On the other hand, unreasonable systems, that are often attributed to the national regulation or ideas presented in the old publications are also found. (author)

  17. Radiation processing of liquid with low energy electron accelerator

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2003-01-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by γ-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with γ-ray should be carried out. (author)

  18. Radiation processing of liquid with low energy electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2003-02-01

    Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

  19. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    Energy Technology Data Exchange (ETDEWEB)

    Debus, Alexander

    2012-09-06

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  20. Brilliant radiation sources by laser-plasma accelerators and optical undulators

    International Nuclear Information System (INIS)

    Debus, Alexander

    2012-01-01

    This thesis investigates the use of high-power lasers for synchrotron radiation sources with high brilliance, from the EUV to the hard X-ray spectral range. Hereby lasers accelerate electrons by laser-wakefield acceleration (LWFA), act as optical undulators, or both. Experimental evidence shows for the first time that LWFA electron bunches are shorter than the driving laser and have a length scale comparable to the plasma wavelength. Furthermore, a first proof of principle experiment demonstrates that LWFA electrons can be exploited to generate undulator radiation. Building upon these experimental findings, as well as extensive numerical simulations of Thomson scattering, the theoretical foundations of a novel interaction geometry for laser-matter interaction are developed. This new method is very general and when tailored towards relativistically moving targets not being limited by the focusability (Rayleigh length) of the laser, while it does not require a waveguide. In a theoretical investigation of Thomson scattering, the optical analogue of undulator radiation, the limits of Thomson sources in scaling towards higher peak brilliances are highlighted. This leads to a novel method for generating brilliant, highly tunable X-ray sources, which is highly energy efficient by circumventing the laser Rayleigh limit through a novel traveling-wave Thomson scattering (TWTS) geometry. This new method suggests increases in X-ray photon yields of 2-3 orders of magnitudes using existing lasers and a way towards efficient, optical undulators to drive a free-electron laser. The results presented here extend far beyond the scope of this work. The possibility to use lasers as particle accelerators, as well as optical undulators, leads to very compact and energy efficient synchrotron sources. The resulting monoenergetic radiation of high brilliance in a range from extreme ultraviolet (EUV) to hard X-ray radiation is of fundamental importance for basic research, medical

  1. Radiation protection for particle accelerators

    International Nuclear Information System (INIS)

    Verdu, G.; Rodenas, J.; Campayo, J.M.

    1992-01-01

    It a a great number of medical installations in spain using particle accelerators for radiotherapy. It is obvious the importance of an accurate estimation of the doses produced in these installations that may be received by health workers, patients or public. The lower values of dose limits established in the new ICRP recommendations imply a recalculation of items concerning such installations. In our country, specific guidelines for radiation protection in particle accelerators facilities have not been yet developed, however two possible guides can be used, NCRP report number 51 and DIN Standard 6847. Both have been analyzed comparatively in the paper, and major remarks have been summarized. Interest has been focused on thickness estimation of shielding barriers in order to verify whether must be modified to comply with the new dose limits. Primary and secondary barriers for a Mevatron used in a Medical Center, have been calculated and the results have been compared with actual data obtained from the installation, to test the adequacy of shielding barriers and radioprotection policies. The results obtained are presented and analyzed in order to state the implications of the new ICRP recommendations. (author)

  2. Radiation shielding and dose rate distribution for the building of the high dose rate accelerator

    International Nuclear Information System (INIS)

    Matsuda, Koji; Takagaki, Torao; Nakase, Yoshiaki; Nakai, Yohta.

    1984-03-01

    A high dose rate electron accelerator was established at Osaka Laboratory for Radiation Chemistry, Takasaki Establishment, JAERI in the fiscal year of 1975. This report shows the fundamental concept for the radiation shielding of the accelerator building and the results of their calculations which were evaluated through the model experiments. After the construction of the building, the leak radiation was measured in order to evaluate the calculating method of radiation shielding. Dose rate distribution of X-rays was also measured in the whole area of the irradiation room as a data base. (author)

  3. Laser Radiation Pressure Accelerator for Quasi-Monoenergetic Proton Generation and Its Medical Implications

    Science.gov (United States)

    Liu, C. S.; Shao, X.; Liu, T. C.; Su, J. J.; He, M. Q.; Eliasson, B.; Tripathi, V. K.; Dudnikova, G.; Sagdeev, R. Z.; Wilks, S.; Chen, C. D.; Sheng, Z. M.

    Laser radiation pressure acceleration (RPA) of ultrathin foils of subwavelength thickness provides an efficient means of quasi-monoenergetic proton generation. With an optimal foil thickness, the ponderomotive force of the intense short-pulse laser beam pushes the electrons to the edge of the foil, while balancing the electric field due to charge separation. The electron and proton layers form a self-organized plasma double layer and are accelerated by the radiation pressure of the laser, the so-called light sail. However, the Rayleigh-Taylor instability can limit the acceleration and broaden the energy of the proton beam. Two-dimensional particle-in-cell (PIC) simulations have shown that the formation of finger-like structures due to the nonlinear evolution of the Rayleigh-Taylor instability limits the acceleration and leads to a leakage of radiation through the target by self-induced transparency. We here review the physics of quasi-monoenergetic proton generation by RPA and recent advances in the studies of energy scaling of RPA, and discuss the RPA of multi-ion and gas targets. The scheme for generating quasi-monoenergetic protons with RPA has the potential of leading to table-top accelerators as sources for producing monoenergetic 50-250 MeV protons. We also discuss potential medical implications, such as particle therapy for cancer treatment, using quasi-monoenergetic proton beams generated from RPA. Compact monoenergetic ion sources also have applications in many other areas such as high-energy particle physics, space electronics radiation testing, and fast ignition in laser fusion.

  4. Remanent radiation fields around medical linear accelerators due to the induced radionuclides

    International Nuclear Information System (INIS)

    Sabol, J.; Khalifa, O.; Berka, Z.; Stankus, P.; Frencl, L.

    1998-01-01

    Radiation fields around two linear accelerators, Saturn 43 and a Saturn 2 Plus, installed at radiotherapy department is Prague, were measured and interpreted. The measurements included the determination of the dose equivalent rate resulting from photons emitted by induced radionuclides produced in reactions of high-energy photons with certain elements present in air and accelerator components as well as in the shielding and building materials in the treatment rooms, which are irradiated by high-energy X-rays, and due to radionuclides formed by capture of photoneutrons. While scattered photons and photoneutrons are only present during the accelerator operation, residual radioactivity creates a remanent radiation field persisting for some time after the instrument shutdown. The activity induced in the accessories is also an important source of exposure. (P.A.)

  5. Treatment of recurrent carcinoma of the paranasal sinuses using concomitant infusion cis-platinum and radiation therapy

    International Nuclear Information System (INIS)

    Rotman, M.; Choi, K.; Isaacson, S.; Rosenthal, J.

    1986-01-01

    Radiation with concomitant infusion chemotherapy has proved more effective in treating several epithelial malignancies than radiation alone. Hyperfractionated radiation was combined with concomitant infusion cis-platinum chemotherapy in an attempt to obtain still better control rates. This paper presents the early results of a pilot study using this combination in the treatment of advanced and recurrent carcinoma of the paranasal sinuses as well as a case that showed response of large fixed cervical nodes having metastasized from a previously treated carcinoma of the maxillary antrum

  6. Radiation protection in large linear accelerators; Seguranca radiologica de aceleradores lineares de grande porte

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, Jose de Jesus Rivero, E-mail: rivero@con.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Departamento de Engenharia Nuclear; Sousa, Fernando Nuno Carneiro de, E-mail: fernandonunosousa@gmail.com [Aceletron Irradiacao lndustrial, Rio de Janeiro, RJ (Brazil)

    2013-07-01

    The electron linear accelerators can be used in industrial applications that require powerful sources of ionizing radiation. They have the important characteristic of not representing a radiation hazard when the accelerators remain electrically disconnected. With the plant in operation, a high reliability defense in depth reduces the risk of radiological accidents to extremely small levels. It is practically impossible that a person could enter into the radiation bunker with the accelerators connected. Aceletron Irradiacao Industrial, located in Rio de Janeiro, offers services of irradiation by means of two powerful electron linear accelerators, with 15 kW power and 10 MeV electron energy. Despite the high level of existing radiation safety, a simplified risk study is underway to identify possible sequences of radiological accidents. The study is based on the combined application of the event and fault trees techniques. Preliminary results confirm that there is a very small risk of entering into the irradiation bunker with the accelerators in operation, but the risk of an operator entering into the bunker during a process interruption and remaining there without notice after the accelerators were restarted may be considerably larger. Based on these results the Company is considering alternatives to reduce the likelihood of human error of this type that could lead to a radiological accident. The paper describes the defense in depth of the irradiation process in Aceletron Irradiacao Industrial, as well as the models and preliminary results of the ongoing risk analysis, including the additional safety measures which are being evaluated. (author)

  7. Radiation Safety System for SPIDER Neutral Beam Accelerator

    International Nuclear Information System (INIS)

    Sandri, S.; Poggi, C.; Coniglio, A.; D'Arienzo, M.

    2011-01-01

    SPIDER (Source for Production of Ion of Deuterium Extracted from RF Plasma only) and MITICA (Megavolt ITER Injector Concept Advanced) are the ITER neutral beam injector (NBI) testing facilities of the PRIMA (Padova Research Injector Megavolt Accelerated) Center. Both injectors accelerate negative deuterium ions with a maximum energy of 1 MeV for MITICA and 100 keV for SPIDER with a maximum beam current of 40 A for both experiments. The SPIDER facility is classified in Italy as a particle accelerator. At present, the design of the radiation safety system for the facility has been completed and the relevant reports have been presented to the Italian regulatory authorities. Before SPIDER can operate, approval must be obtained from the Italian Regulatory Authority Board (IRAB) following a detailed licensing process. In the present work, the main project information and criteria for the SPIDER injector source are reported together with the analysis of hypothetical accidental situations and safety issues considerations. Neutron and photon nuclear analysis is presented, along with special shielding solutions designed to meet Italian regulatory dose limits. The contribution of activated corrosion products (ACP) to external exposure of workers has also been assessed. Nuclear analysis indicates that the photon contribution to worker external exposure is negligible, and the neutron dose can be considered by far the main radiation protection issue. Our results confirm that the injector has no important radiological impact on the population living around the facility.

  8. The personnel protection system for a Synchrotron Radiation Accelerator Facility: Radiation safety perspective

    International Nuclear Information System (INIS)

    Liu, J.C.

    1993-05-01

    The Personnel Protection System (PPS) at the Stanford Synchrotron Radiation Laboratory is summarized and reviewed from the radiation safety point of view. The PPS, which is designed to protect people from radiation exposure to beam operation, consists of the Access Control System (ACS) and the Beam Containment System (BCS), The ACS prevents people from being exposed to the very high radiation level inside the shielding housing (also called a PPS area). The ACS for a PPS area consists of the shielding housing and a standard entry module at every entrance. The BCS prevents people from being exposed to the radiation outside a PPS area due to normal and abnormal beam losses. The BCS consists of the shielding (shielding housing and metal shielding in local areas), beam stoppers, active current limiting devices, and an active radiation monitor system. The system elements for the ACS and BCS and the associated interlock network are described. The policies and practices in setting up the PPS are compared with some requirements in the US Department of Energy draft Order of Safety of Accelerator Facilities

  9. Electron acceleration and radiation signatures in loop coronal transients

    International Nuclear Information System (INIS)

    Vlahos, L.; Gergely, T.E.; Papadopoulos, K.

    1982-01-01

    A model for electron aceleration in loop coronal transients is suggested. We propose that in these transients an erupting loop moves away from the solar surface, with a velocity greater than the local Alfven speed, pushing against the overlying magnetic fields and driving a shock in the front of the moving part of the loop. We suggest that lower hybrid waves are excited at the shock front and propagate radially toward the center of the loop with phase velocity along the magnetic field which exceeds the thermal velocity. The lower hybrid waves stochastically accelerate the tail of the electron distribution inside the loop. We discuss how the accelerated electrons are trapped in the moving loop and give a rough estimate of their radiation signature. We find that plasma radiation can explain the power observed in stationary and moving type IV bursts. We discuss some of the conditions under which moving or stationary type IV bursts are expected to be associated with loop coronal transients

  10. NIST Accelerator Facilities And Programs In Support Of Industrial Radiation Research

    International Nuclear Information System (INIS)

    Bateman, F.B.; Desrosiers, M.F.; Hudson, L.T.; Coursey, B.M.; Bergstrom, P.M. Jr.; Seltzer, S.M.

    2003-01-01

    NIST's Ionizing Radiation Division maintains and operates three electron accelerators used in a number of applications including waste treatment and sterilization, radiation hardness testing, detector calibrations and materials modification studies. These facilities serve a large number of governmental, academic and industrial users as well as an active intramural research program. They include a 500 kV cascaded-rectifier accelerator, a 2.5 MV electron Van de Graaff accelerator and a 7 to 32 MeV electron linac, supplying beams ranging in energy from a few keV up to 32 MeV. In response to the recent anthrax incident, NIST along with the US Postal Service and the Armed Forces Radiobiology Research Institute (AFRRI) are working to develop protocols and testing procedures for the USPS mail sanitization program. NIST facilities and personnel are being employed in a series of quality-assurance measurements for both electron- and photon-beam sanitization. These include computational modeling, dose verification and VOC (volatile organic compounds) testing using megavoltage electron and photon sources

  11. Radiation vulcanization of natural rubber latex with low energy accelerator-II

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Md. Emdadul; Makuuchi, Keizo; Ikeda, Kenichi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Dept. of Biological and Chemical Engineering, Kiryu, Gunma (Japan)

    2002-03-01

    The natural rubber latex (NRL) was radiation vulcanized under a low energy electron accelerator. Accelerating voltage and maximum beam current of this accelerator are 250 kV and 10 mA respectively. Irradiation was carried out in a reaction vessel with constant stirring. The capacity of the vessel is 18 liters. Radiation vulcanization accelerators (RVA) were normal butyl acrylate (n-BA) and nonane-diol-diacrylate (NDDA). NDDA has no bad smell like that of n-BA. 20 minutes irradiation time is enough to vulcanize 14 liters of latex when 5 phr RVA (both types) are used. Maximum of {approx}30 MPa tensile strength was obtained with 5 phr NDD-A. However the remained NDDA is difficult to remove due to high molecular weight. Water-extractable proteins content was determined in dipped films for various leaching conditions without and with additive (polyvinyl alcohol, PVA). Water extractable proteins content is reduced to {<=} 41 by adding 5 phr PVA and leaching for 8 hours. The tackiness of the dipped films is reduced to 0.1 from 9 gf by mixing 6 phr PVA with the irradiated latex. Hand gloves (surgical and examination) were successfully produced from the irradiated latex. (author)

  12. Experimental research on electromagnetic radiation in inductive energy storage accelerator

    International Nuclear Information System (INIS)

    Zhong Jianzhong; Liu Lie; Li Limin; Wen Jianchun

    2008-01-01

    There exists strong electromagnetic radiation in inductive energy storage accelerators. In can destroy a measuring device at a distance. By repeated experiments, we found that it is a wide-spectrum electromagnetic wave with a main frequency of 75 MHz. The effector such as coaxial transmission line is effected strongly in short distance. The current in the coaxial transmission line can be measured in Rogowski coils. The strength of field in it is about 500 V/m and the peak current is 217 mA. The radiation source may be LC oscillating or electric exploding opening switch. Through the experimental research, we think it probably may be caused by the LC oscillating in the circuit when the switches conduct. And its strength is correlated to current change ratio. The change rate in secondary circuit is stronger than in primary circuit. So the radiation generated in secondary circuit is stronger than in primary circuit. It may be a reference for further research in inductive energy storage accelerators and shielding electromagnetic disturbing. (authors)

  13. Monte Carlo simulations of ultra high vacuum and synchrotron radiation for particle accelerators

    CERN Document Server

    AUTHOR|(CDS)2082330; Leonid, Rivkin

    With preparation of Hi-Lumi LHC fully underway, and the FCC machines under study, accelerators will reach unprecedented energies and along with it very large amount of synchrotron radiation (SR). This will desorb photoelectrons and molecules from accelerator walls, which contribute to electron cloud buildup and increase the residual pressure - both effects reducing the beam lifetime. In current accelerators these two effects are among the principal limiting factors, therefore precise calculation of synchrotron radiation and pressure properties are very important, desirably in the early design phase. This PhD project shows the modernization and a major upgrade of two codes, Molflow and Synrad, originally written by R. Kersevan in the 1990s, which are based on the test-particle Monte Carlo method and allow ultra-high vacuum and synchrotron radiation calculations. The new versions contain new physics, and are built as an all-in-one package - available to the public. Existing vacuum calculation methods are overvi...

  14. Betatron radiation based diagnostics for plasma wakefield accelerated electron beams at the SPARC-LAB test facility

    Energy Technology Data Exchange (ETDEWEB)

    Shpakov, V.; Anania, M.P.; Biagioni, A.; Chiadroni, E. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); Cianchi, A. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); “Tor Vergata” University, via della Ricerca Scientifica 1, 00133 Rome (Italy); Curcio, A. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); Dabagov, S. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); P.N. Lebedev Physical Institute RAS, Leninskiy Prospekt 53, 119991 Moscow (Russian Federation); NRNU “MEPhI”, Kashirskoe highway 31, 115409 Moscow (Russian Federation); Ferrario, M.; Filippi, F. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); Marocchino, A. [Dipartimento SBAI Universitá di Roma ‘La Sapienza’, via Antonio Scarpa 14/16, 00161 Rome (Italy); Paroli, B. [INFN - MI, via Celoria 16, 20133 Milan (Italy); Pompili, R. [INFN - LNF, via Enrico Fermi 40, 00044 Frascati (Italy); Rossi, A.R. [INFN - MI, via Celoria 16, 20133 Milan (Italy); Zigler, A. [Racah Institute of Physics Hebrew University of Jerusalem (Israel)

    2016-09-01

    Recent progress with wake-field acceleration has shown a great potential in providing high gradient acceleration fields, while the quality of the beams remains relatively poor. Precise knowledge of the beam size at the exit from the plasma and matching conditions for the externally injected beams are the key for improvement of beam quality. Betatron radiation emitted by the beam during acceleration in the plasma is a powerful tool for the transverse beam size measurement, being also non-intercepting. In this work we report on the technical solutions chosen at SPARC-LAB for such diagnostics tool, along with expected parameters of betatron radiation. - Highlights: • The betatron radiation parameters in SPARC-LAB wakefiled experiments were studied. • The differences with betatron radiation in other wake-field experiments were highlighted. • The solution for betatron radiation detection was investigated.

  15. Betatron radiation based diagnostics for plasma wakefield accelerated electron beams at the SPARC-LAB test facility

    International Nuclear Information System (INIS)

    Shpakov, V.; Anania, M.P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Curcio, A.; Dabagov, S.; Ferrario, M.; Filippi, F.; Marocchino, A.; Paroli, B.; Pompili, R.; Rossi, A.R.; Zigler, A.

    2016-01-01

    Recent progress with wake-field acceleration has shown a great potential in providing high gradient acceleration fields, while the quality of the beams remains relatively poor. Precise knowledge of the beam size at the exit from the plasma and matching conditions for the externally injected beams are the key for improvement of beam quality. Betatron radiation emitted by the beam during acceleration in the plasma is a powerful tool for the transverse beam size measurement, being also non-intercepting. In this work we report on the technical solutions chosen at SPARC-LAB for such diagnostics tool, along with expected parameters of betatron radiation. - Highlights: • The betatron radiation parameters in SPARC-LAB wakefiled experiments were studied. • The differences with betatron radiation in other wake-field experiments were highlighted. • The solution for betatron radiation detection was investigated.

  16. Use of heavy ion accelerators in fusion reactor-related radiation-damage studies

    International Nuclear Information System (INIS)

    Taylor, A.; Dobson, D.A.

    1974-01-01

    The heavy-ion accelerator has become an important tool in the study of the fundamentals of radiation damage in fission- and fusion-reactor materials. Present facilities for such studies within the Materials Science Division at Argonne National Laboratory are provided by two complementary accelerator systems. Examples of the work carried out are discussed

  17. DART-bid: dose-differentiated accelerated radiation therapy, 1.8 Gy twice daily. High local control in early stage (I/II) non-small-cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zehentmayr, Franz; Wurstbauer, Karl; Deutschmann, Heinz; Sedlmayer, Felix [Landeskrankenhaus Salzburg, Univ.-Klinik fuer Radiotherapie und Radio-Onkologie, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversitaet, Salzburg (Austria); Paracelsus Medizinische Privatuniversitaet, Institute for Research and Development of Advanced Radiation Technologies (radART), Salzburg (Austria); Fussl, Christoph; Kopp, Peter; Dagn, Karin; Fastner, Gerd [Landeskrankenhaus Salzburg, Univ.-Klinik fuer Radiotherapie und Radio-Onkologie, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversitaet, Salzburg (Austria); Porsch, Peter; Studnicka, Michael [Landeskrankenhaus Salzburg, Univ.-Klinik fuer Pneumologie, Univ.-Klinikum der Paracelsus Medizinischen Privatuniversitaet, Salzburg (Austria)

    2014-09-23

    While surgery is considered standard of care for early stage (I/II), non-small-cell lung cancer (NSCLC), radiotherapy is a widely accepted alternative for medically unfit patients or those who refuse surgery. International guidelines recommend several treatment options, comprising stereotactic body radiation therapy (SBRT) for small tumors, conventional radiotherapy ≥ 60 Gy for larger sized especially centrally located lesions or continuous hyperfractionated accelerated RT (CHART). This study presents clinical outcome and toxicity for patients treated with a dose-differentiated accelerated schedule using 1.8 Gy bid (DART-bid). Between April 2002 and December 2010, 54 patients (median age 71 years, median Karnofsky performance score 70 %) were treated for early stage NSCLC. Total doses were applied according to tumor diameter: 73.8 Gy for < 2.5 cm, 79.2 Gy for 2.5-4.5 cm, 84.6 Gy for 4.5-6 cm, 90 Gy for > 6 cm. The median follow-up was 28.5 months (range 2-108 months); actuarial local control (LC) at 2 and 3 years was 88 %, while regional control was 100 %. There were 10 patients (19 %) who died of the tumor, and 18 patients (33 %) died due to cardiovascular or pulmonary causes. A total of 11 patients (20 %) died intercurrently without evidence of progression or treatment-related toxicity at the last follow-up, while 15 patients (28 %) are alive. Acute esophagitis ≤ grade 2 occurred in 7 cases, 2 patients developed grade 2 chronic pulmonary fibrosis. DART-bid yields high LC without significant toxicity. For centrally located and/or large (> 5 cm) early stage tumors, where SBRT is not feasible, this method might serve as radiotherapeutic alternative to present treatment recommendations, with the need of confirmation in larger cohorts. (orig.) [German] Die Standardbehandlung fuer nichtkleinzellige Bronchialkarzinome (NSCLC) im Stadium I/II ist die Operation, wobei Radiotherapie fuer Patienten, die nicht operabel sind oder die Operation ablehnen, als Alternative

  18. Time-dose modifications

    International Nuclear Information System (INIS)

    Kian Ang, K.

    1987-01-01

    Changes in fractionation schedule can be made by various approaches. However, from the first principle, it is anticipated that strategies of hyperfractionation and/or accelerated fractionation offer the most promised in improving the therapeutic ratio. Hyperfractionation is defined as a treatment schedule in which a large number of significantly reduced dose fractions (--1.2 Gy/fraction) is used to give a greater total dose in a conventional overall time period. The results of the pilot studies testing the efficacy of hyperfractionation have been encouraging. The most valid clinical trial of pure hyperfractionation, however, is that conducted by the EORTC. This study compared 70 Gy in 35 fractions or 80.5 Gy in 70 fractions over 7 weeks in the treatment of patients with oropharyngeal carcinomas. The local tumor control was significantly improved in the hyperfractionated arm without increasing the morbidity. Accelerated fractionation is defined as a schedule in which the overall time of treatment is reduced without significant changes in the total dose and fraction size. The strategy has been used to treat patients with malignant gliomas, melanomas and Head and Neck cancers. The data in Head and Neck Cancers seem to be promising

  19. PREFACE: Acceleration and radiation generation in space and laboratory plasmas

    Science.gov (United States)

    Bingham, R.; Katsouleas, T.; Dawson, J. M.; Stenflo, L.

    1994-01-01

    Sixty-six leading researchers from ten nations gathered in the Homeric village of Kardamyli, on the southern coast of mainland Greece, from August 29-September 4, 1993 for the International Workshop on Acceleration and Radiation Generation in Space and Laboratory Plasmas. This Special Issue represents a cross-section of the presentations made at and the research stimulated by that meeting. According to the Iliad, King Agamemnon used Kardamyli as a dowry offering in order to draw a sulking Achilles into the Trojan War. 3000 years later, Kardamyli is no less seductive. Its remoteness and tranquility made it an ideal venue for promoting the free exchange of ideas between various disciplines that do not normally interact. Through invited presen tations, informal poster discussions and working group sessions, the Workshop brought together leaders from the laboratory and space/astrophysics communities working on common problems of acceleration and radiation generation in plasmas. It was clear from the presentation and discussion sessions that there is a great deal of common ground between these disciplines which is not at first obvious due to the differing terminologies and types of observations available to each community. All of the papers in this Special Issue highlight the role collective plasma processes play in accelerating particles or generating radiation. Some are state-of-the-art presentations of the latest research in a single discipline, while others investi gate the applicability of known laboratory mechanisms to explain observations in natural plasmas. Notable among the latter are the papers by Marshall et al. on kHz radiation in the magnetosphere ; Barletta et al. on collective acceleration in solar flares; and by Dendy et al. on ion cyclotron emission. The papers in this Issue are organized as follows: In Section 1 are four general papers by Dawson, Galeev, Bingham et al. and Mon which serves as an introduction to the physical mechanisms of acceleration

  20. Ion acceleration by radiation pressure in thin and thick targets

    Energy Technology Data Exchange (ETDEWEB)

    Macchi, Andrea, E-mail: macchi@df.unipi.i [CNR/INFM/polyLAB, Pisa (Italy); Dipartimento di Fisica ' Enrico Fermi' , Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Benedetti, Carlo, E-mail: Carlo.Benedetti@bo.infn.i [Dipartimento di Fisica, Universita di Bologna and INFN, Via Irnerio 46, I-40126 Bologna (Italy)

    2010-08-01

    Radiation Pressure Acceleration (RPA) by circularly polarized laser pulses is emerging as a promising way to obtain efficient acceleration of ions. We briefly review theoretical work on the topic, aiming at characterizing suitable experimental scenarios. We discuss the two reference cases of RPA, namely the thick target ('Hole Boring') and the (ultra)thin target ('Light Sail') regimes. The different scaling laws of the two regimes, the related experimental challenges and their suitability for foreseen applications are discussed.

  1. Repetitive nanosecond electron accelerators type URT-1 for radiation technology

    Science.gov (United States)

    Sokovnin, S. Yu.; Balezin, M. E.

    2018-03-01

    The electron accelerator URT-1М-300 for mobile installation was created for radiation disinfecting to correct drawbacks that were found the URT-1M electron accelerator operation (the accelerating voltage up to 1 МV, repetition rate up to 300 pps, electron beam size 400 × 100 mm, the pulse width about 100 ns). Accelerator configuration was changed that allowed to reduce significantly by 20% tank volume with oil where is placed the system of formation high-voltage pulses, thus the average power of the accelerator is increased by 6 times at the expense of increase in pulses repetition rate. Was created the system of the computerized monitoring parameters (output parameters and thermal mode) and remote control of the accelerator (charge voltage, pulse repetition rate), its elements and auxiliary systems (heat of the thyratron, vacuum system), the remote control panel is connected to the installation by the fiber-optical channel, what lightens the work for service personnel. For generating an electron beam up to 400 mm wide there are used metal- ceramic] and metal-dielectric cold cathodes of several emission elements (plates) with a non-uniform distribution of the electron beam current density on the output foil ± 15%. It was found that emission drop of both type of cathodes, during the operation at the high repetition rate (100 pps) is substantial at the beginning of the process, and then proceeds rather slowly that allows for continuous operation up to 40 h. Experiments showed that linear dependence of the voltage and a signal from the pin-diode remains within the range of the charge voltage 45-65 kV. Thus, voltage increases from 690 to 950 kV, and the signal from the pin-diode - from (2,8-4,6)*104 Gy/s. It allows to select electron energy quite precisely with consideration of the radiation technology requirements.

  2. Hyperfractionated Radiotherapy and Concurrent Chemotherapy for Stage III Unascertainable Non Small Cell Lung Cancer : Preliminary Report for Response and Toxicity

    International Nuclear Information System (INIS)

    Choi, Eun Kyung; Kim, Jong Hoon; Chang, Hye Sook

    1995-01-01

    Lung cancer study group at Asan Medical Center has conducted the second prospective study to determine the efficacy and feasibility of MVP chemotherapy with concurrent hyperfractionated radiotherapy for patients with stage III unresectable non-small cell lung cancer(NSCLC). All eligible patients with stage III unresectable NSCLC were treated with hyperfractionated radiotherapy( 120 cGy/fx BID, 6480 cGY/54fx) and concurrent 2 cycles of MVP(Motomycin C 6 mg/m 2 , d2 and d29, Vinblastin 6 mg/m 2 , d2 and d29, Cisplatin 6 mg/m 2 , d1 and d28) chemotherapy. Between Aug. 1993 and Nov. 1994, 62 patients entered this study ; 6(10%) had advanced stage IIIa and 56(90%) had IIIb disease including 1 with pleural effusion and 10 with supraclavicular metastases. Among 62 Patients, 48(77%) completed planned therapy. Fourteen patients refused further treatment during chemoradiotherapy. Of 46 patients evaluable for response, 34(74%) showed major response including 10(22%) with complete and 24(52%) with partial responses. Of 48 patients evaluable for toxicity, 13(27%) showed grade IV hematologic toxicity but treatment delay did not exceed 5 days. Two patients died of sepsis during chemoradiotherapy. Server weight(more than 10%) occurred in 9 patients(19%) during treatment. Nine patients(19%) developed radiation pneumonitis. Six of these patients had grad I(mild) pneumonitis with radiographic changes within the treatment fields. Three other patients had grade II pneumonitis, but none of theses patients had continuous symptoms after steroid treatment. Concurrent chemoradiotherapy for patients with advanced NSCLC was well tolerated with acceptable toxicity and achieved higher response rates than the first study, but rather low compliance rate(7%) in this study is worrisome. We need to improve nutritional support during treatment and to use G-CSF to improve leukopenia and if necessary, supportive care will given as in patients. Longer follow-up and larger sample size is needed to

  3. Laser Acceleration of Quasi-Monoenergetic Protons via Radiation Pressure Driven Thin Foil

    International Nuclear Information System (INIS)

    Liu, Chuan S.; Shao Xi; Liu, T. C.; Dudnikova, Galina; Sagdeev, Roald Z.; Eliasson, Bengt

    2011-01-01

    We present a theoretical and simulation study of laser acceleration of quasi-monoenergetic protons in a thin foil irradiated by high intensity laser light. The underlying physics of radiation pressure acceleration (RPA) is discussed, including the importance of optimal thickness and circularly polarized light for efficient acceleration of ions to quasi-monoenergetic beams. Preliminary two-dimensional simulation studies show that certain parameter regimes allow for stabilization of the Rayleigh-Taylor instability and possibility of acceleration of monoenergetic ions to an excess of 200 MeV, making them suitable for important applications such as medical cancer therapy and fast ignition.

  4. Damping in accelerators due to classical radiation

    International Nuclear Information System (INIS)

    Mills, F.E.

    1962-01-01

    The rates of change of the magnitudes of the adiabatic invariants is calculated in the case of a Hamiltonian system subjected to generalized non conservative forces. These results are applied to the case of the classical radiation of electrons in an accelerator or storage ring. The resulting expressions for the damping rates of three independent oscillation modes suggest structures which are damping in all three modes, while at the same time allowing 'strong focussing' and the attendant strong momentum compaction. (author)

  5. Bookshelf (H. Wade Patterson and Ralph H. Thomas, editors; 'A History of Accelerator Radiation Protection')

    International Nuclear Information System (INIS)

    Hoefert, Manfred

    1994-01-01

    This book is a collection of contributions on the history of accelerator radiation protection by people who have worked or still work in this field at particle accelerators around the world. The radiation environment of these machines is the most complex man-made radiation field one could face. In fact, protection efforts must cover a large spectrum of particles and energies ranging from thermal, in the case of neutrons, to the primary energy of the accelerator. Therefore the correct assessment of the exposure risk for people working in such stray radiation fields is a theme of many of the articles. The editors deliberately refrained from guiding the authors' styles, so the book contains a collection of papers ranging from articles with literary ambitions to dry accounts on radiation protection efforts around a particular accelerator complex. Although this retains the originality of the individual contributions, one would have liked to see a somewhat more anecdotal/historical approach rather than concentrating on scientific depth. Considering the types and energies of the radiations involved another outstanding and reoccurring issue is the question of accelerator shielding, where correct answers require considerable experimental and calculational efforts. While no shielding (it has happened!) proved to be bad, overshielding never turned out to be a problem in view of the increase in intensities that older machines have gone on to achieve. Is this a book only for the few radiation protection specialists working in an accelerator environment? Not necessarily. The physics aspects of radiation protection (generally called health physics in the US) is always evident and makes many articles interesting to read even for the non-specialist. The editors' epilogue proudly claims that most health physicists working around accelerators regard themselves as the elite of their profession. On the other hand the statement made by one eminent colleague - &apos

  6. Gas-phase hydrosilylation of cyclohexene in an experimental radiation-chemical accelerator apparatus

    International Nuclear Information System (INIS)

    Pecherkin, A.S.; Sidorov, V.I.; Chernyshev, E.A.

    1992-01-01

    A process for the synthesis of methylcyclohexyldichlorosilane (a basic monomer for the production of organosilicon photoresists) has been investigated and perfected on an experimental apparatus with an ELV-2 electron accelerator; this synthesis involves gas-phase radiation-induced hydrosilylation of cyclohexene by methyldichlorosilane. Basic characteristics of the yield of the desired product under static conditions were determined. With the help of experiments on the synthesis of methylcyclohexyldichlorosilane in a flow- through mode, the technical features of the process of radiation-chemical hydrosilylation of cyclohexene on an accelerator apparatus were determined and studied, the optimal conditions for the synthesis were determined, and an experimental batch of the desired product was produced

  7. SHF radiation of plasma and acceleration regime of a discharge in the Tokamak FT-1

    International Nuclear Information System (INIS)

    Larionov, M.M.; Levin, L.S.; Rozhdestvenskij, V.V.; Tokunov, A.I.

    1975-01-01

    It is studied the frequency spectrum of SHF radiation, hard X-radiation, diamagnetism, conductivity and density of plasma in high-temperature and accelerating regimes of the FT-1 tokamak. It is shown that the intensities of hard X-radiation and SHF radiation in an accelerating discharge are far more than in a high-temperature discharge. In the first case radiation temperature of the SHF range reaches 7 keV while in the second one it will be 7 eV. The difference in the radiations points to the diverse role of electron running-away. The total and transverse energies of run-away electrons are evaluated according to the X-ray energy and SHF radiation. The transverse energy of the run-away electrons is found to be 80 keV. This value permits interpretation of the observed plasma diamagnetism

  8. Present status of radiation processing and its future development by using electron accelerator in Vietnam

    International Nuclear Information System (INIS)

    Tran Khac An; Tran Tich Canh; Doan Binh; Nguyen Quoc Hien

    2003-01-01

    In Vietnam, studies on Radiation Processing have been carried out since 1983. Some results are applicable in the field of agriculture, health and foodstuff, some researches were developed to commercial scale and others have high potential for development by using electron accelerator. The paper offers the present status of radiation processing and also give out the growing tendency of using electron accelerator in the future. (author)

  9. Present status of radiation processing and its future development by using electron accelerator in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Tran Khac An; Tran Tich Canh; Doan Binh [Research and Development Center for Radiation Technology (VINAGAMMA), Ho Chi Minh (Viet Nam); Nguyen Quoc Hien [Nuclear Research Institute (NRI), Dalat (Viet Nam)

    2003-02-01

    In Vietnam, studies on Radiation Processing have been carried out since 1983. Some results are applicable in the field of agriculture, health and foodstuff, some researches were developed to commercial scale and others have high potential for development by using electron accelerator. The paper offers the present status of radiation processing and also give out the growing tendency of using electron accelerator in the future. (author)

  10. A pilot study of hyperfractionated radiotherapy for infants with retinoblastoma

    International Nuclear Information System (INIS)

    Harris, Eleanor E.R.; Meadows, Anna T.; Shields, Jerry; D'Angio, Giulio J.; Goldwein, Joel W.

    1996-01-01

    was preserved in 70% of patients. Radiation complications include none in 3 of 10 patients, mild orbital hypoplasia in the radiation field in 5 patients, cataracts in 3 patients and ocular loss in 1 patient (2 eyes) with bilateral local recurrences who was salvaged with bilateral plaque therapy but later required bilateral enucleations for pain and glaucoma. All cataracts were successfully treated. One patient developed an in-field second malignancy (nasopharyngeal sarcoma) at 4 years. Cataracts and bony hypoplasia were seen in patients treated with both en face electrons and opposed lateral photon fields. Conclusions: Twice daily external beam radiation therapy to 43-45 Gy in combination with other local therapies achieved survival of 80%, a local control rate of 84%, and an ocular preservation rate of 74% in a group of 10 infants with advanced intraocular retinoblastoma. These results compare favorably to other series reporting on patients with advanced intraocular disease. Our results suggest that hyperfractionated irradiation as primary therapy has an acceptable complication rate including mild orbital hypoplasia and treatable cataracts with no vision loss attributable to external beam irradiation alone. In addition, based on our review of the literature, the tumor control and ocular preservation may be better than with conventional fractionation

  11. Radiation reaction effect on laser driven auto-resonant particle acceleration

    International Nuclear Information System (INIS)

    Sagar, Vikram; Sengupta, Sudip; Kaw, P. K.

    2015-01-01

    The effects of radiation reaction force on laser driven auto-resonant particle acceleration scheme are studied using Landau-Lifshitz equation of motion. These studies are carried out for both linear and circularly polarized laser fields in the presence of static axial magnetic field. From the parametric study, a radiation reaction dominated region has been identified in which the particle dynamics is greatly effected by this force. In the radiation reaction dominated region, the two significant effects on particle dynamics are seen, viz., (1) saturation in energy gain by the initially resonant particle and (2) net energy gain by an initially non-resonant particle which is caused due to resonance broadening. It has been further shown that with the relaxation of resonance condition and with optimum choice of parameters, this scheme may become competitive with the other present-day laser driven particle acceleration schemes. The quantum corrections to the Landau-Lifshitz equation of motion have also been taken into account. The difference in the energy gain estimates of the particle by the quantum corrected and classical Landau-Lifshitz equation is found to be insignificant for the present day as well as upcoming laser facilities

  12. Short term ionizing radiation impact on charge-coupled devices in radiation environment of high-intensity heavy ion accelerators

    International Nuclear Information System (INIS)

    Belousov, A.; Mustafin, E.; Ensinger, W.

    2012-01-01

    This paper presents a first approach on studies of the results of short term ionizing radiation impact on charge-coupled device (CCD) chips in conditions typical for high-intensity ion accelerator areas. Radiation effects on semiconductor devices are a topical issue for high-intensity accelerator projects. In particular it concerns CCD cameras that are widely used for beam profile monitoring and surveillance in high radiation environment. 65 CCD cameras are going to be installed in the FAIR machines. It is necessary to have good understanding of radiation effects and their contribution to measured signal in CCD chips. A phenomenon of single event upset (SEU) in CCD chips is studied in the following experiment. By SEU in CCD chip we mean an event when an ionizing particle hits the CCD matrix cell and produces electron-hole pairs that are then collected and converted to a signal that is higher than certain level defined by author. Practically, it means that a certain cell will appear as a bright pixel on the resulting image from a chip. (authors)

  13. Design considerations for the use of laser-plasma accelerators for advanced space radiation studies

    Science.gov (United States)

    Königstein, T.; Karger, O.; Pretzler, G.; Rosenzweig, J. B.; Hidding, B.; Hidding

    2012-08-01

    We present design considerations for the use of laser-plasma accelerators for mimicking space radiation and testing space-grade electronics. This novel application takes advantage of the inherent ability of laser-plasma accelerators to produce particle beams with exponential energy distribution, which is a characteristic shared with the hazardous relativistic electron flux present in the radiation belts of planets such as Earth, Saturn and Jupiter. Fundamental issues regarding laser-plasma interaction parameters, beam propagation, flux development, and experimental setup are discussed.

  14. Electron accelerators for radiation processing: Criterions of selection and exploitation

    International Nuclear Information System (INIS)

    Zimek, Zbigniew

    2001-01-01

    The progress in accelerator technology is tightly attached to the continuously advanced development in many branches of technical activity. Although the present level of accelerators development can satisfy most of the commercial requirements, this field continues to expand and improve quality by offering efficient, cheap, reliable, high average beam power commercial units. Accelerator construction must be a compromised between size, efficiency and cost with respect to the field of its application. High power accelerators have been developed to meet specific demands of flue gas treatment and other high throughput to increase the capacity of the progress and reduced unit cost of operation. Automatic control, reliability and reduced maintenance, adequate adoption to process conditions, suitable electron energy and beam power are the basic features of modern accelerator construction. Accelerators have the potential to serve as industrial radiation sources and eventually may replace the isotope sources in future. Electron beam plants can transfer much higher amounts of energy into the irradiated objects than other types of facilities including gamma plants. This provides the opportunity to construct technological lines with high capacity that are more technically and economically suitable with high throughputs, short evidence time and grate versatility

  15. Radiation pressure acceleration: The factors limiting maximum attainable ion energy

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, S. S.; Esarey, E.; Schroeder, C. B. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Bulanov, S. V. [KPSI, National Institutes for Quantum and Radiological Science and Technology, Kizugawa, Kyoto 619-0215 (Japan); A. M. Prokhorov Institute of General Physics RAS, Moscow 119991 (Russian Federation); Esirkepov, T. Zh.; Kando, M. [KPSI, National Institutes for Quantum and Radiological Science and Technology, Kizugawa, Kyoto 619-0215 (Japan); Pegoraro, F. [Physics Department, University of Pisa and Istituto Nazionale di Ottica, CNR, Pisa 56127 (Italy); Leemans, W. P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Physics Department, University of California, Berkeley, California 94720 (United States)

    2016-05-15

    Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it transparent for radiation and effectively terminating the acceleration. The off-normal incidence of the laser on the target, due either to the experimental setup, or to the deformation of the target, will also lead to establishing a limit on maximum ion energy.

  16. Hyperfractionated high-dose total body irradiation in bone marrow transplantation for Ph{sup 1}-positive acute lymphoblastic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Akira; Ebihara, Yasuhiro; Mitsui, Tetsuo [Tokyo Univ. (Japan). Hospital of the Institute of Medical Science] [and others

    1998-12-01

    In two cases of Philadelphia-positive childhood acute lymphoblastic leukemia (Ph{sup 1} ALL), we performed allogeneic bone marrow transplantation (AlloBMT) with preconditioning regimen, including hyperfractionated high-dose total body irradiation (TBI) (13.5 Gy, in 9 fractions). Their disease statuses at BMT were hematological relapse in case 1 and molecular relapse in case 2. Bone marrow donors were unrelated in case 1, and HLA was a partially mismatched mother in case 2. Regimen-related toxicity was tolerable in both cases. Hematological recovery was rapid, and engraftment was obtained on day 14 in case 1 and on day 12 in case 2. BCR/ABL message in bone marrow disappeared on day 89 in case 1 and on day 19 in case 2 and throughout their subsequent clinical courses. Although short-term MTX and Cy-A continuous infusion were used for GVHD prophylaxis, grade IV GVHD was observed in case 1 and grade III in case 2. Both cases experienced hemorrhagic cystitis because of adenovirus type 11 infection. Although case 1 died of interstitial pneumonitis on day 442, case 2 has been free of disease through day 231. AlloBMT for Ph{sup 1} ALL with preconditioning regimen including hyperfractionated high-dose TBI is considered to be worth further investigation. (author)

  17. Modelling of radiation losses for ion acceleration at ultra-high laser intensities

    Directory of Open Access Journals (Sweden)

    Capdessus Remi

    2013-11-01

    Full Text Available Radiation losses of charged particles can become important in ultra high intensity laser plasma interaction. This process is described by the radiation back reaction term in the electron equation of motion. This term is implemented in the relativistic particle-in-cell code by using a renormalized Lorentz-Abraham-Dirac model. In the hole boring regime case of laser ion acceleration it is shown that radiation losses results in a decrease of the piston velocity.

  18. Heavy ion linear accelerator for radiation damage studies of materials

    Energy Technology Data Exchange (ETDEWEB)

    Kutsaev, Sergey V.; Mustapha, Brahim; Ostroumov, Peter N.; Nolen, Jerry; Barcikowski, Albert; Pellin, Michael; Yacout, Abdellatif

    2017-03-01

    A new eXtreme MATerial (XMAT) research facility is being proposed at Argonne National Laboratory to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. This facility combines a new heavy-ion accelerator with the existing high-energy X-ray analysis capability of the Argonne Advanced Photon Source. The heavy-ion accelerator and target complex will enable experimenters to emulate the environment of a nuclear reactor making possible the study of fission fragment damage in materials. Material scientists will be able to use the measured material parameters to validate computer simulation codes and extrapolate the response of the material in a nuclear reactor environment. Utilizing a new heavy-ion accelerator will provide the appropriate energies and intensities to study these effects with beam intensities which allow experiments to run over hours or days instead of years. The XMAT facility will use a CW heavy-ion accelerator capable of providing beams of any stable isotope with adjustable energy up to 1.2 MeV/u for U-238(50+) and 1.7 MeV for protons. This energy is crucial to the design since it well mimics fission fragments that provide the major portion of the damage in nuclear fuels. The energy also allows damage to be created far from the surface of the material allowing bulk radiation damage effects to be investigated. The XMAT ion linac includes an electron cyclotron resonance ion source, a normal-conducting radio-frequency quadrupole and four normal-conducting multi-gap quarter-wave resonators operating at 60.625 MHz. This paper presents the 3D multi-physics design and analysis of the accelerating structures and beam dynamics studies of the linac.

  19. Heavy ion linear accelerator for radiation damage studies of materials.

    Science.gov (United States)

    Kutsaev, Sergey V; Mustapha, Brahim; Ostroumov, Peter N; Nolen, Jerry; Barcikowski, Albert; Pellin, Michael; Yacout, Abdellatif

    2017-03-01

    A new eXtreme MATerial (XMAT) research facility is being proposed at Argonne National Laboratory to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. This facility combines a new heavy-ion accelerator with the existing high-energy X-ray analysis capability of the Argonne Advanced Photon Source. The heavy-ion accelerator and target complex will enable experimenters to emulate the environment of a nuclear reactor making possible the study of fission fragment damage in materials. Material scientists will be able to use the measured material parameters to validate computer simulation codes and extrapolate the response of the material in a nuclear reactor environment. Utilizing a new heavy-ion accelerator will provide the appropriate energies and intensities to study these effects with beam intensities which allow experiments to run over hours or days instead of years. The XMAT facility will use a CW heavy-ion accelerator capable of providing beams of any stable isotope with adjustable energy up to 1.2 MeV/u for 238 U 50+ and 1.7 MeV for protons. This energy is crucial to the design since it well mimics fission fragments that provide the major portion of the damage in nuclear fuels. The energy also allows damage to be created far from the surface of the material allowing bulk radiation damage effects to be investigated. The XMAT ion linac includes an electron cyclotron resonance ion source, a normal-conducting radio-frequency quadrupole and four normal-conducting multi-gap quarter-wave resonators operating at 60.625 MHz. This paper presents the 3D multi-physics design and analysis of the accelerating structures and beam dynamics studies of the linac.

  20. Dependence of the ion energy on the parameters of the laser pulse and target in the radiation-pressure-dominated regime of acceleration

    International Nuclear Information System (INIS)

    Echkina, E. Yu.; Inovenkov, I. N.; Esirkepov, T. Zh.; Pegoraro, F.; Borghesi, M.; Bulanov, S. V.

    2010-01-01

    When the dominant mechanism for ion acceleration is the laser radiation pressure, the conversion efficiency of the laser energy into the energy of relativistic ions may be very high. Stability analysis of a thin plasma layer accelerated by the radiation pressure shows that Raleigh-Taylor instability may enhance plasma inhomogeneity. In the linear stage of instability, the plasma layer decays into separate bunches, which are accelerated by the radiation pressure similarly to clusters accelerated under the action of an electromagnetic wave. The energy and luminosity of an ion beam accelerated in the radiation-pressure-dominated regime are calculated.

  1. Accelerated radiation damage test facility using a 5 MV tandem ion accelerator

    International Nuclear Information System (INIS)

    Wady, P.T.; Draude, A.; Shubeita, S.M.; Smith, A.D.; Mason, N.; Pimblott, S.M.; Jimenez-Melero, E.

    2016-01-01

    We have developed a new irradiation facility that allows to perform accelerated damage tests of nuclear reactor materials at temperatures up to 400 °C using the intense proton (<100 μA) and heavy ion (≈10 μA) beams produced by a 5 MV tandem ion accelerator. The dedicated beam line for radiation damage studies comprises: (1) beam diagnosis and focusing optical components, (2) a scanning and slit system that allows uniform irradiation of a sample area of 0.5–6 cm"2, and (3) a sample stage designed to be able to monitor in-situ the sample temperature, current deposited on the sample, and the gamma spectrum of potential radio-active nuclides produced during the sample irradiation. The beam line capabilities have been tested by irradiating a 20Cr–25Ni–Nb stabilised stainless steel with a 3 MeV proton beam to a dose level of 3 dpa. The irradiation temperature was 356 °C, with a maximum range in temperature values of ±6 °C within the first 24 h of continuous irradiation. The sample stage is connected to ground through an electrometer to measure accurately the charge deposited on the sample. The charge can be integrated in hardware during irradiation, and this methodology removes uncertainties due to fluctuations in beam current. The measured gamma spectrum allowed the identification of the main radioactive nuclides produced during the proton bombardment from the lifetimes and gamma emissions. This dedicated radiation damage beam line is hosted by the Dalton Cumbrian Facility of the University of Manchester.

  2. Stable radiation pressure acceleration of ions by suppressing transverse Rayleigh-Taylor instability with multiple Gaussian pulses

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, M. L.; Liu, B.; Hu, R. H.; Shou, Y. R.; Lin, C.; Lu, H. Y.; Lu, Y. R.; Ma, W. J., E-mail: wenjun.ma@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, CAPT, Peking University, Beijing 100871 (China); Gu, Y. Q. [Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China); Yan, X. Q., E-mail: x.yan@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, CAPT, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006 (China)

    2016-08-15

    In the case of a thin plasma slab accelerated by the radiation pressure of an ultra-intense laser pulse, the development of Rayleigh-Taylor instability (RTI) will destroy the acceleration structure and terminate the acceleration process much sooner than theoretical limit. In this paper, a new scheme using multiple Gaussian pulses for ion acceleration in a radiation pressure acceleration regime is investigated with particle-in-cell simulation. We found that with multiple Gaussian pulses, the instability could be efficiently suppressed and the divergence of the ion bunch is greatly reduced, resulting in a longer acceleration time and much more collimated ion bunch with higher energy than using a single Gaussian pulse. An analytical model is developed to describe the suppression of RTI at the laser-plasma interface. The model shows that the suppression of RTI is due to the introduction of the long wavelength mode RTI by the multiple Gaussian pulses.

  3. Determination of radiation levels by neutrons in an accelerator for radiotherapy

    International Nuclear Information System (INIS)

    Paredes G, L.; Salazar B, M.A.; Genis S, R.

    1998-01-01

    It was determined the radiation levels by neutrons due to photonuclear reactions (γ, n) which occur in the target, levelling filter, collimators and the small pillow blinding of a medical accelerator Varian Clinac 2100C of 18 MeV, using thermoluminescent dosemeters UD-802AS and US-809AS. The experimental values were presented for the patient level, inside and outside of the radiation field, as well as for the small pillow. (Author)

  4. A guide to radiation and radioactivity levels near high energy particle accelerators

    International Nuclear Information System (INIS)

    Sullivan, A.H.

    1992-01-01

    An estimate of likely radiation and radioactivity levels is needed at the design stage of an accelerator for deciding the radiation safety features to be incorporated in the infrastructure of the machine and for predicting where radiation damage possibilities will have to be taken into account. Both these aspects can have a significant influence on the machine layout and cost. Failure to make a reasonable assessment at the right time may have far reaching consequences for future costs. The purpose of this guide is to bring together basic data and methods that have been found useful in assessing radiation situations around accelerators and to provide a practical means of arriving at the radiation and induced radioactivity levels that could occur under a wide variety of circumstances. An attempt is made to present the information in a direct and unambiguous way with sufficient confidence that the necessity for large safety factors is avoided. In many cases assumptions and simplifications have been made and reliance placed on extrapolating from experimental data into regions where the basic physics is too complicated to make meaningful absolute calculations. Wherever possible such extrapolations have been tied to real or otherwise acceptable data originating from independent sources. (Author)

  5. Accelerated hypofractionated radiation therapy compared to conventionally fractionated radiation therapy for the treatment of inoperable non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Amini Arya

    2012-03-01

    Full Text Available Abstract Background While conventionally fractionated radiation therapy alone is an acceptable option for poor prognostic patients with unresectable stage III NSCLC, we hypothesized that accelerated hypofractionated radiotherapy will have similar efficacy without increasing toxicity. Methods This is a retrospective analysis of 300 patients diagnosed with stage III NSCLC treated between 1993 and 2009. Patients included in the study were medically or surgically inoperable, were free of metastatic disease at initial workup and did not receive concurrent chemotherapy. Patients were categorized into three groups. Group 1 received 45 Gy in 15 fractions over 3 weeks (Accelerated Radiotherapy (ACRT while group 2 received 60-63 Gy (Standard Radiation Therapy 1 (STRT1 and group 3 received > 63 Gy (Standard Radiation Therapy (STRT2. Results There were 119 (39.7% patients in the ACRT group, 90 (30.0% in STRT1 and 91 (30.3% in STRT2. More patients in the ACRT group had KPS ≤ 60 (p 5% (p = 0.002, and had stage 3B disease (p Conclusions Despite the limitations of a retrospective analysis, our experience of accelerated hypofractionated radiation therapy with 45 Gy in 15 fractions appears to be an acceptable treatment option for poor performance status patients with stage III inoperable tumors. Such a treatment regimen (or higher doses in 15 fractions should be prospectively evaluated using modern radiation technologies with the addition of sequential high dose chemotherapy in stage III NSCLC.

  6. Simulation of the Focal Spot of the Accelerator Bremsstrahlung Radiation

    Science.gov (United States)

    Sorokin, V.; Bespalov, V.

    2016-06-01

    Testing of thick-walled objects by bremsstrahlung radiation (BR) is primarily performed via high-energy quanta. The testing parameters are specified by the focal spot size of the high-energy bremsstrahlung radiation. In determining the focal spot size, the high- energy BR portion cannot be experimentally separated from the low-energy BR to use high- energy quanta only. The patterns of BR focal spot formation have been investigated via statistical modeling of the radiation transfer in the target material. The distributions of BR quanta emitted by the target for different energies and emission angles under normal distribution of the accelerated electrons bombarding the target have been obtained, and the ratio of the distribution parameters has been determined.

  7. Spallation radiation damage and dosimetry for accelerator transmutation of waste applications

    International Nuclear Information System (INIS)

    Wechsler, M.S.; Lin, C.

    1993-01-01

    Proposals are currently being made for systems to treat radioactive waste based on the use of accelerator-driven neutron sources. A linear proton accelerator with energies as high as 1600 MeV and currents up to 250 ma are anticipated for the driver. The neutron fluxes may reach up to 10 20 neutrons/m 2 s as generated by the spallation reactions that occur when the protons strike target materials. Calculations are described to determine radiation fluxes and flux spectra inherent in such systems and to estimate likely radiation effects on system components. The calculations use LAHET, a Monte Carlo high-energy transport code, and MCNP, a generalized-geometry, coupled neutron-photon Monte Carlo transport code. Cross sections for displacement and helium production are presented for spallation neutrons of energies from 21 MeV to 1600 MeV for Inconel 718 (Ni plus 18.5, 18.5, 5.1, and 3 wt % of Cr, Fe, Nb, and Mo, respectively), an alloy that is used for the proton beam entry window in several accelerators. In addition, results for this alloy are presented for the primary knocked-on atom (PKA) spectrum and the transmutation yield for 1600 MeV incident neutrons

  8. Modeling classical and quantum radiation from laser-plasma accelerators

    Directory of Open Access Journals (Sweden)

    M. Chen

    2013-03-01

    Full Text Available The development of models and the “Virtual Detector for Synchrotron Radiation” (vdsr code that accurately describe the production of synchrotron radiation are described. These models and code are valid in the classical and linear (single-scattering quantum regimes and are capable of describing radiation produced from laser-plasma accelerators (LPAs through a variety of mechanisms including betatron radiation, undulator radiation, and Thomson/Compton scattering. Previous models of classical synchrotron radiation, such as those typically used for undulator radiation, are inadequate in describing the radiation spectra from electrons undergoing small numbers of oscillations. This is due to an improper treatment of a mathematical evaluation at the end points of an integration that leads to an unphysical plateau in the radiation spectrum at high frequencies, the magnitude of which increases as the number of oscillation periods decreases. This is important for betatron radiation from LPAs, in which the betatron strength parameter is large but the number of betatron periods is small. The code vdsr allows the radiation to be calculated in this regime by full integration over each electron trajectory, including end-point effects, and this code is used to calculate betatron radiation for cases of experimental interest. Radiation from Thomson scattering and Compton scattering is also studied with vdsr. For Thomson scattering, radiation reaction is included by using the Sokolov method for the calculation of the electron dynamics. For Compton scattering, quantum recoil effects are considered in vdsr by using Monte Carlo methods. The quantum calculation has been benchmarked with the classical calculation in a classical regime.

  9. Interactive Visual Intervention Planning: Interactive Visualization for Intervention Planning in Particle Accelerator Environments with Ionizing Radiation

    CERN Document Server

    Fabry, Thomas; Feral, Bruno

    2013-01-01

    Intervention planning is crucial for maintenance operations in particle accelerator environments with ionizing radiation, during which the radiation dose contracted by maintenance workers should be reduced to a minimum. In this context, we discuss the visualization aspects of a new software tool, which integrates interactive exploration of a scene depicting an accelerator facility augmented with residual radiation level simulations, with the visualization of intervention data such as the followed trajectory and maintenance tasks. The visualization of each of these aspects has its effect on the final predicted contracted radiation dose. In this context, we explore the possible benefits of a user study, with the goal of enhancing the visual conditions in which the intervention planner using the software tool is minimizing the radiation dose.

  10. Discussion of feasibility to carry out intensity modulated radiation therapy in conventional medical electron linear accelerator treatment rooms

    International Nuclear Information System (INIS)

    Yang Haiyou; Liu Liping; Liang Yueqin; Zhang Liang; Yu Shui

    2010-01-01

    Objective: To investigate the feasibility about the shielding effect of conventional medical electron linear accelerator treatment in the existing rooms to carry out intensity modulated radiation therapy (IMRT). Methods: The estimation model given in NCRP REPORT No. 151- S tructural Shielding Design and Evaluation for Megavoltage X-and Gamma-Ray Radiotherapy Facilities i s adopted by linking instances, which presents the calculation methods on radiation level at the ambience of megavoltage medical electron linear accelerator treatment room. Results: The radiation level, as well as the additional annual effect dose of occupational and public at the ambience of accelerator treatment room, in crease to a certain extent, when conventional medical electron linear accelerator treatment room; are used to carry out IMRT. Conclusion: It is necessary to make environmental impact assessment for conventional medical electron linear accelerator treatment rooms, which will be used to execute IMRT. (authors)

  11. Hyperfractionated radiotherapy (2100 cGY) for stage 4 neuroblastoma as part of intensive multimodality therapy

    International Nuclear Information System (INIS)

    Gollamudi, S.V.; Kushner, B.H.; Merchant, T.E.; LaQuaglia, M.; Lindsley, K.; Rosenfield, N.; Abramson, S.; Kramer, K.; Cheung, N.K.V.

    1997-01-01

    PURPOSE: To retrospectively evaluate the role of hyperfractionated radiotherapy to the primary site following induction chemotherapy and aggressive surgical resection in patients (pts) with stage 4 neuroblastoma. MATERIALS AND METHODS: 48 previously untreated children (median age at diagnosis 3 yo, range 1-10 yo) with stage 4 neuroblastoma achieved a complete-, near-complete-, or partial-remission after multimodality therapy (protocol N4: 6 pts, N5: 7 pts, N6: 27 pts, or N7: 8 pts). All protocols included a regimen consisting of dose-intensive multiagent chemotherapy, maximal surgical debulking, followed by hyperfractionated radiotherapy. Most pts then underwent consolidation with either autologous marrow transplantation (N4 and N5), or immunotherapy (N6 and N7) with radioimmunotherapy (N7). Of 48 pts, 46 had microscopic disease at the primary site prior to beginning radiotherapy (45 underwent gross total resection of the primary, and one had no residual primary disease after chemotherapy alone). One pt had a partial resection, and one remained unresectable after mutimodality therapy. The pre-chemotherapy volume of the primary tumor and regional lymph nodes were irradiated to a total dose of 2100cGy delivered twice-daily in 150 cGy fractions over 7 treatment days. RESULTS: With a median follow-up of 32.5 months (range= 8-145 months), local-regional control was achieved in 44 of the 48 pts. Of the pts who are progression-free, median follow-up was 53.5 months. Overall, 24 of 48 pts progressed, three with local-regional recurrence as the first site of relapse, one with distant failure first and subsequent local-regional recurrence, and 21 with distant failure only. The probability of local-regional control at 32 months was 83%. One of the four pts with local-regional relapse never achieved a complete remission with either systemic therapy, surgical resection or radiotherapy. The progression-free survival at 32 months was 46%. Median time to overall progression was 16

  12. Hyperfractionated Radiotherapy Following Induction Chemotherapy for Stage III Non-Small Cell Lung Cancer-Random iced for Adjuvant Chemotherapy vs. Observation

    International Nuclear Information System (INIS)

    Choi, Eun Kyung; Chang, Hye Sook; Ahn, Seung Do

    1993-01-01

    Since Jan. 1991 a prospective randomized study for Stage III unresectable non small cell lung cancer(NSCLC) has been conducted to evaluate the response rate and tolerance of induction chemotherapy with MVP followed by hyperfractionated radiotherapy and evaluate the efficacy of maintenance chemotherapy in Asan Medical Center. All patients in this study were treated with hypefractionated radiotherapy (120 cGy/fx BID, 0480 cGy/54 fx) following 3 cycles of induction chemotherapy, MVP (Mitomycin C 6 mg/m2, Vinblastin B mg/ m2, Cisplatin 60 Mg/ m2) and then the partial and complete responders from induction chemotherapy were randomized to 3 cycles of adjuvant MVP chemotherapy group and observation group. 48 patients were registered to this study until December 1992; among 48 patients 3 refused further treatment after induction chemotherapy and 6 received incomplete radiation therapy because of patient refusal, 39 completed planned therapy. Twenty-three(58%) patients including 2 complete responders showed response from induction chemotherapy. Among the 21 patients who achieved a partial response after induction chemotherapy, 1 patient rendered complete clearance of disease and 10 patients showed further regression of tumor following hypefractionated radiotherapy. Remaining 10 patients showed stable disease or progression after radiotherapy. Of the sixteen patients judged to have stable disease or progression after induction chemotherapy, seven showed more than partial remission after radiotherapy but nine showed no response in spite of radiotherapy. Of the 35 patients who completed induction chemotherapy and radiotherapy, 25 patients(64%) including 3 complete responders showed more than partial remission. Nineteen patients were randomized after radiotherapy. Nine patients were allocated to adjuvant chemotherapy group and 4/9 shewed further regression of tumor after adjuvant chemotherapy. For the time being, there is no suggestion of a difference between the adjuvant

  13. Radiation control at the Continuous Electron Beam Accelerator Facility (CEBAF), a new high power CW electron accelerator installation

    International Nuclear Information System (INIS)

    Stapleton, G.B.; Thomas, R.H.

    1989-01-01

    A description is given of the design goals and radiation control measures, for a new 4 GeV, 1 MW electron accelerator under construction in the USA. The paper illustrates the importance of cooperation between designers and regulators. 15 refs., 1 fig., 3 tabs

  14. Hyperfractionated total body irradiation for T-depleted HLA identical bone marrow transplants

    International Nuclear Information System (INIS)

    Latini, P.; Checcaglini, F.; Maranzano, E.; Aristei, C.; Panizza, B.M.; Gobbi, G.; Raymondi, C.; Aversa, F.; Martelli, M.F.

    1988-01-01

    Twenty patients suffering from malignant hemopathies (mean age 31.7 years) were given hyperfractionated total body irradiation (TBI) as conditioning for T-depleted HLA identical allogeneic bone marrow transplantation. At an average of 12 months (range of 4.5-22 months) follow-up there were two cases of early death and two cases (11%) of rejection. There were no cases of acute or chronic graft versus host disease nor cases of interstitial pneumonitis. The average time for durable engraftment was 22 days. Disease-free survival at 12 months was 65%. To improve the results and further reduce the percent of rejection, the authors propose intensifying the immunosuppressive conditioning by increasing the cyclophosphamide dose and that of TBI so that a total dose of 1560 cGy is reached. 35 refs.; 1 figure

  15. Structure, shape, and evolution of radiatively accelerated QSO emission-line clouds

    International Nuclear Information System (INIS)

    Blumenthal, G.R.; Mathews, W.G.

    1979-01-01

    The possibility that the broad emission-line regions of QSOs and active galactic nuclei are formed by a multitude of small clouds which are radiatively accelerated is discussed. Although this model is by no means certain at present, it has four virtues: (1) Observed emission-line widths can be produced with observationally allowed electron densities, UV luminosities, and ionization levels. (2) The acceleration force is coherent in each cloud are found. (3) Reasonable line profiles can result for all emission lines. (4) Photoionization of hydrogen accounts for both heating and acceleration of the emission-line gas. A self-consistent model is developed for the structure, shape, and evolution of radiatively accelerated clouds. The shape varies with cloud mass, and two distinct types of clouds. Fully ionized clouds of very low mass approach a nearly spherical shape. However, all clouds having masses greater than some critical mass adopt a ''pancake'' shape. The condition for constant cloud mass in the cloud frame is shown to be equivalent to the equation of motion of a cloud in the rest frame of the QSO. The emission-line profiles can be sensitive to radial variations in the properties of the intercloud medium, and those properties that correspond to observed profiles are discussed. Finally, the covering factor of a system of pancake clouds is estimated along with the total number of clouds required--approximately 10 14 clouds in each QSO

  16. Normal tissue tolerance to external beam radiation therapy: Spinal cord; Tolerance a l'irradiation des tissus sains: moelle epiniere

    Energy Technology Data Exchange (ETDEWEB)

    Habrand, J.L. [Departement de radiotherapie, institut Gustave-Roussy, 94 - Villejuif (France); Centre de protontherapie, institut Curie, 91 - Orsay (France); Drouet, F. [Departement de radiotherapie, centre Rene-Gauducheau, 44 - Nantes (France)

    2010-07-15

    Radiation myelopathy is one of the most dreadful complications of radiation therapy. Despite multiple animal experiments and human autopsic series, its pathogenesis remains largely unknown. In most instances, the classical aspect of myelomalacia combines glial and vascular injuries in various sequences. Recent studies point out the role of oligo-dendrocytes and their precursors, as well as of intercellular mediators (cytokines and stress molecules). The clinical presentation comprises a spectrum of non specific neurological symptoms whose evolution is sometimes regressive but more commonly progressive and life-threatening. Usually, it occurs following a latent period of six months to two years after irradiation of the cervical, thoracic or upper lumbar spine to a dose in excess of 50 Gy, conventionally fractionated. Nonetheless, these typical features can be altered by extrinsic factors, such as hypo fractionation/acceleration of the dose, multiple surgical procedures, chemotherapy especially mega therapy, or neurotoxic drugs. Conversely, hyperfractionated regimens that take into account protracted half-time repair of sublethal damages to the CNS, as well as sophisticated estimates of the dose to the cord and QA programs during the treatment course minimize such risks. (authors)

  17. A grey diffusion acceleration method for time-dependent radiative transfer calculations: analysis and application

    International Nuclear Information System (INIS)

    Nowak, P.F.

    1993-01-01

    A grey diffusion acceleration method is presented and is shown by Fourier analysis and test calculations to be effective in accelerating radiative transfer calculations. The spectral radius is bounded by 0.9 for the continuous equations, but is significantly smaller for the discretized equations, especially in the optically thick regimes characteristic to radiation transport problems. The GDA method is more efficient than the multigroup DSA method because its slightly higher iteration count is more than offset by the much lower cost per iteration. A wide range of test calculations confirm the efficiency of GDA compared to multifrequency DSA. (orig.)

  18. Application of nonlinear Krylov acceleration to radiative transfer problems

    International Nuclear Information System (INIS)

    Till, A. T.; Adams, M. L.; Morel, J. E.

    2013-01-01

    The iterative solution technique used for radiative transfer is normally nested, with outer thermal iterations and inner transport iterations. We implement a nonlinear Krylov acceleration (NKA) method in the PDT code for radiative transfer problems that breaks nesting, resulting in more thermal iterations but significantly fewer total inner transport iterations. Using the metric of total inner transport iterations, we investigate a crooked-pipe-like problem and a pseudo-shock-tube problem. Using only sweep preconditioning, we compare NKA against a typical inner / outer method employing GMRES / Newton and find NKA to be comparable or superior. Finally, we demonstrate the efficacy of applying diffusion-based preconditioning to grey problems in conjunction with NKA. (authors)

  19. Influence of post-radiation, accelerate annealing and discreteness on the TID parameters of memerizer

    International Nuclear Information System (INIS)

    Wang Qunyong; Liu Yanfang; Chen Yu; Jiang Dayong; Bai Ye; Song Yan

    2010-01-01

    By the study of post-radiation and accelerate annealing in the total ionizing dose (TID), we find out that the additional 50% dose radiation and high temperature accelerate annealing (100 degree C 168 h) can not be skipped in the test because it is necessary to strictly check the memory's TID effect in the space radiation environment. The analysis of device's discreteness in the test shows that parameters of device should be tested before the radiation to get their standard deviation. The high reliability of the memorizer which used in the satellite can be ensured by rejecting the device which increases the standard deviation. The TID test in the NASA report have been confirmed that the effectiveness of parameter test in 'read-only', 'write' and 'erase' mode is better than the test in 'only read' mode as it can reflect the degradation characteristics of the memorizer following ionizing radiation more reasonable. The test sequence applied for each memory at any electrical measurement steps after exposures annealing should be considered. (authors)

  20. Radiation doses inside industrial irradiation installation with linear electron accelerator

    International Nuclear Information System (INIS)

    Lima, Alexandre R.; Pelegrineli, Samuel Q.; Alo, Gabriel F.; Silva, Francisco C.A. Da

    2015-01-01

    Aceletron Industrial Irradiation Company is the unique installation in South America to provide industrial irradiation service using two linear electron accelerators of 18 kW and 10 MeV energy. The electron beam technology allows using electrons to irradiate many goods and materials, such as hospital and medical equipment, cosmetics, herbal products, polymers, peat, gemstones and food. Aceletron Company uses a concrete bunker with 3.66 m of thickness to provide the necessary occupational and environmental radiation protection of X-rays produced. The bunker is divided in main four areas: irradiation room, maze, tower and pit. Inside the irradiation room the x-rays radiation rates are measured in two ways: direct beam and 90 deg C. The rates produced in the conveyor system using 10 MeV energy are 500 Gy/min/mA and 15 Gy/min/mA, respectively. For a 1.8 mA current, the rates produced are 900 Gy/min and 27 Gy/min, respectively. Outside the bunker the radiation rate is at background level, but in the tower door and modulation room the radiation rate is 10 μSv/h. In 2014, during a routine operation, an effective dose of 30.90 mSv was recorded in a monthly individual dosimeter. After the investigation, it was concluded that the dose was only in the dosimeter because it felt inside the irradiation room. As Aceletron Company follows the principles of safety culture, it was decided to perform the radiation isodose curves, inside the four areas of the installation, to know exactly the hotspots positions, exposure times and radiation doses. Five hotspots were chosen taking into account worker's routes and possible operational places. The first experiment was done using a package with three TLD and OSLD dosimeters to obtain better statistical results. The first results for the five hotspots near the accelerator machine showed that the radiation dose rates were between 26 Gy/h and 31 Gy/h. The final measurements were performed using a package with one TLD and one OSLD

  1. Radiation doses inside industrial irradiation installation with linear electron accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Alexandre R., E-mail: alexandre.lima@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Pelegrineli, Samuel Q.; Alo, Gabriel F., E-mail: samuelfisica@yahoo.com.br, E-mail: gabriel.alo@aceletron.com.br [Aceletron Irradiacao Industrial, Aceletrica Comercio e Representacoes Ltda, Rio de Janeiro, RJ (Brazil); Silva, Francisco C.A. Da, E-mail: dasilva@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Aceletron Industrial Irradiation Company is the unique installation in South America to provide industrial irradiation service using two linear electron accelerators of 18 kW and 10 MeV energy. The electron beam technology allows using electrons to irradiate many goods and materials, such as hospital and medical equipment, cosmetics, herbal products, polymers, peat, gemstones and food. Aceletron Company uses a concrete bunker with 3.66 m of thickness to provide the necessary occupational and environmental radiation protection of X-rays produced. The bunker is divided in main four areas: irradiation room, maze, tower and pit. Inside the irradiation room the x-rays radiation rates are measured in two ways: direct beam and 90 deg C. The rates produced in the conveyor system using 10 MeV energy are 500 Gy/min/mA and 15 Gy/min/mA, respectively. For a 1.8 mA current, the rates produced are 900 Gy/min and 27 Gy/min, respectively. Outside the bunker the radiation rate is at background level, but in the tower door and modulation room the radiation rate is 10 μSv/h. In 2014, during a routine operation, an effective dose of 30.90 mSv was recorded in a monthly individual dosimeter. After the investigation, it was concluded that the dose was only in the dosimeter because it felt inside the irradiation room. As Aceletron Company follows the principles of safety culture, it was decided to perform the radiation isodose curves, inside the four areas of the installation, to know exactly the hotspots positions, exposure times and radiation doses. Five hotspots were chosen taking into account worker's routes and possible operational places. The first experiment was done using a package with three TLD and OSLD dosimeters to obtain better statistical results. The first results for the five hotspots near the accelerator machine showed that the radiation dose rates were between 26 Gy/h and 31 Gy/h. The final measurements were performed using a package with one TLD and one OSLD

  2. Complex workplace radiation fields at European high-energy accelerators and thermonuclear fusion facilities

    CERN Document Server

    Bilski, P; D'Errico, F; Esposito, A; Fehrenbacher, G; Fernàndez, F; Fuchs, A; Golnik, N; Lacoste, V; Leuschner, A; Sandri, S; Silari, M; Spurny, F; Wiegel, B; Wright, P

    2006-01-01

    This report outlines the research needs and research activities within Europe to develop new and improved methods and techniques for the characterization of complex radiation fields at workplaces around high-energy accelerators and the next generation of thermonuclear fusion facilities under the auspices of the COordinated Network for RAdiation Dosimetry (CONRAD) project funded by the European Commission.

  3. High Energy Ion Acceleration by Extreme Laser Radiation Pressure

    Science.gov (United States)

    2017-03-14

    published in the internationally leading journal Physical Review Letters. We continued to progress this pionee 15.  SUBJECT TERMS ion therapy, heavy ion ...Thomson parabola spectrometer: To separate and provide a measurement of the charge -to-mass ratio and energy spectrum of the different ion species...AFRL-AFOSR-UK-TR-2017-0015 High energy ion acceleration by extreme laser radiation pressure Paul McKenna UNIVERSITY OF STRATHCLYDE VIZ ROYAL COLLEGE

  4. Radiation protection system installation for the accelerator production of tritium/low energy demonstration accelerator project (APT/LEDA)

    CERN Document Server

    Wilmarth, J E; Tomei, T L

    2000-01-01

    The APT/LEDA personnel radiation protection system installation was accomplished using a flexible, modular proven system which satisfied regulatory orders, project design criteria, operational modes, and facility requirements. The goal of providing exclusion and safe access of personnel to areas where prompt radiation in the LEDA facility is produced was achieved with the installation of a DOE-approved Personnel Access Control System (PACS). To satisfy the facility configuration design, the PACS, a major component of the overall radiation safety system, conveniently provided five independent areas of personnel access control. Because of its flexibility and adaptability the Los-Alamos Neutron- Science-Center-(LANSCE)-designed Radiation Security System (RSS) was efficiently configured to provide the desired operational modes and satisfy the APT/LEDA project design criteria. The Backbone Beam Enable (BBE) system based on the LANSCE RSS provided the accelerator beam control functions with redundant, hardwired, ta...

  5. Induction chemotherapy followed by simultaneous hyperfractionated radiochemotherapy in advanced head and neck cancer. A pilot study

    International Nuclear Information System (INIS)

    Jereczek-Fossa, B.; Medical Univ. Gdansk; De Braud, F.; Gasparetto, M.; De Pas, T.; Tradati, N.; Leonardi, M.C.; Marsiglia, H.R.; Orecchia, R.; Milan Univ.

    1998-01-01

    Purpose: To evaluate the feasibility of induction chemotherapy followed by concomitant chemotherapy and hyperfractionated irradiation in locally advanced, inoperable head and neck cancer. Methods: A pilot study was undertaken comprising 3 cycles of cisplatinum (100 mg/m 2 , day 1) and 5-fluorouracil (1000 mg/m 2 in continuous intravenous infusion over the first 120 h) followed by bifractionated radiotherapy applied to tumor/involved lymph nodes up to the dose of 74.4 Gy given in 2 fractions of 1.2 Gy daily for 5 days a week combined with concomitant weekly cisplatinum infusion (50 mg/m 2 ). Results: Six patients were enrolled in the study. All of them completed the protocol therapy. Severe mucositis and myelotoxicity were the most common acute side effects observed in all and in 5 of the patients, respectively. Acute toxicity required interruption of concomitant chemotherapy in 5 cases and in 2 interruption of radiotherapy was necessary. Opioid analgesic parenteral therapy was administered in 4 patients. Three of them had to be hospitalized. One patient experienced cerebral stroke 1 day after the completion of therapy and died 7 days later. Due to high acute toxicity, patient accrual was terminated after 6 patients. At the mean follow-up of 17 months, 4 patients are alive, 3 of them are free of disease and in 1 local progression has been diagnosed. Conclusions: High acute toxicity of induction cisplatinum and 5-fluorouracil followed by concomitant cisplatinum and hyperfractionated irradiation calls for less toxic treatment schedules in locally advanced inoperable head and neck cancer. (orig.) [de

  6. Hyperfractionated radiaton therapy and bis-chlorethyl nitrosourea in the treatment of malignant glioma - possible advantage observed at 72.0 Gy in 1.2 Gy B.I.D. fractions: Report of the radiation therapy oncology group protocol 8302

    International Nuclear Information System (INIS)

    Nelson, D.F.; Curran, W.J.; Powlis, W.D.; Scott, C.; Nelson, J.S.; Weinstein, A.S.; Ahmad, K.; Constine, L.S.; Murray, K.; Mohiuddin, M.; Fischbach, J.

    1993-01-01

    Between January 1983 and November 1987, the Radiation Therapy Oncology Group conducted a prospective, randomized, multi-institutional, dose searching Phase I/II trial to evaluate hyperfractionated radiation therapy in the treatment of supratentorial malignant glioma. Patients with anaplastic astrocytoma, or glioblastoma multiforme, age 18-70 years with a Karnofsky performance status of 40-100 were stratified according to age, Karnofsky performance status, and histology, and were randomized. Initially randomization was to one of three arms: 64.8 Gy, 72.0 Gy, and 76.8 Gy. Fractions of 1.2 Gy were given twice daily, 5 days per week, with intervals of 4 to 8 hr. All patients received bis-chlorethyl nitrosourea (BCNU) 80 mg/m2 on days 3, 4, 5 of radiation therapy and then every 8 weeks for 1 year. After acceptable rates of acute and late effects were found, the randomization was changed to 81.6 Gy and 72.0 Gy with a weighting of 2:1. Out of 466 patients randomized, 435 were analyzed. The distribution of prognostic factors was comparable among the 76.8 Gy arm, 81.6 Gy arm, and the final randomization of the 72 Gy arm. The 64.8 Gy arm and the initial randomization of the 72 Gy arm had somewhat worse prognostic variables. Late radiation toxicity occurred in 1.3-6.8% of the patients, with a modest increase with increasing radiation dose. The best survival occurred in those patients treated with 72 Gy. The Cox proportional hazards model confirmed the prognostic variables of age, histology and Karnofsky performance status. In addition, the longer interval of 4.5-8 hr was associated with a worse prognosis than the 4-4.4 hr interval. The difference in survival between the 81.6 Gy arm and the lower three arms approached significance with inferior survival observed in the 81.6 Gy arm. 72 Gy delivered by 1.2 Gy twice daily is no more toxic than 60 Gy delivered conventionally. 26 refs., 6 figs., 7 tabs

  7. Design of a grating for studying Smith-Purcell radiation and electron acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1989-01-01

    We describe work on the design of a diffraction grating which we intend to use for studying the production of Smith-Purcell radiation and the acceleration of electrons. We have developed computer codes based on the solution of the appropriate Maxwell's equations. A specific grating profile is given which is feasible to construct and which supports enhanced surface accelerating modes. We examine the possibility of using the Smith-Purcell effect to make a beam position monitor. 13 refs., 10 figs., 2 tabs

  8. Design of a grating for studying Smith-Purcell radiation and electron acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1989-01-01

    We describe work on the design fo a diffracton grating which we intend to use for studying the production of Smith-Purcell radiation and the acceleration of electrons. We have developed computer codes based on the solution of the appropriate Maxwell's equations. A specific grating profile is given which is feasible to construct and which supports enhanced surface accelerating modes. We examine the possibility of using the Smith-Purcell effect to make a beam position monitor. copyright 1989 American Institute of Physics

  9. Common genomic signaling among initial DNA damage and radiation-induced apoptosis in peripheral blood lymphocytes from locally advanced breast cancer patients

    DEFF Research Database (Denmark)

    Henríquez-Hernández, Luis Alberto; Pinar, Beatriz; Carmona-Vigo, Ruth

    2013-01-01

    PURPOSE: To investigate the genomic signaling that defines sensitive lymphocytes to radiation and if such molecular profiles are consistent with clinical toxicity; trying to disclose the radiobiology mechanisms behind these cellular processes. PATIENTS AND METHODS: Twelve consecutive patients...... suffering from locally advanced breast cancer and treated with high-dose hyperfractionated radiotherapy were recruited. Initial DNA damage was measured by pulsed-field gel electrophoresis and radiation-induced apoptosis was measured by flow cytometry. Gene expression was assessed by DNA microarray. RESULTS...

  10. Preliminary analysis of accelerated space flight ionizing radiation testing

    Science.gov (United States)

    Wilson, J. W.; Stock, L. V.; Carter, D. J.; Chang, C. K.

    1982-01-01

    A preliminary analysis shows that radiation dose equivalent to 30 years in the geosynchronous environment can be accumulated in a typical composite material exposed to space for 2 years or less onboard a spacecraft orbiting from perigee of 300 km out to the peak of the inner electron belt (approximately 2750 km). Future work to determine spacecraft orbits better tailored to materials accelerated testing is indicated. It is predicted that a range of 10 to the 9th power to 10 to the 10th power rads would be accumulated in 3-6 mil thick epoxy/graphite exposed by a test spacecraft orbiting in the inner electron belt. This dose is equivalent to the accumulated dose that this material would be expected to have after 30 years in a geosynchronous orbit. It is anticipated that material specimens would be brought back to Earth after 2 years in the radiation environment so that space radiation effects on materials could be analyzed by laboratory methods.

  11. Activation and radiation damage in the environment of hadron accelerators

    CERN Document Server

    Kiselev, Daniela

    2013-01-01

    A component which suffers radiation damage usually also becomes radioactive, since the source of activation and radiation damage is the interaction of the material with particles from an accelerator or with reaction products. However, the underlying mechanisms of the two phenomena are different. These mechanisms are described here. Activation and radiation damage can have far-reaching consequences. Components such as targets, collimators, and beam dumps are the first candidates for failure as a result of radiation damage. This means that they have to be replaced or repaired. This takes time, during which personnel accumulate dose. If the dose to personnel at work would exceed permitted limits, remote handling becomes necessary. The remaining material has to be disposed of as radioactive waste, for which an elaborate procedure acceptable to the authorities is required. One of the requirements of the authorities is a complete nuclide inventory. The methods used for calculation of such inventories are presented,...

  12. Coherent radiation from high-current electron beams of linear accelerators and its applications

    International Nuclear Information System (INIS)

    Okuda, Shuichi; Takanaka, Makoto; Nakamura, Mitsumi; Kato, Ryukou; Takahashi, Toshiharu; Nam, Soon-Kwon; Taniguchi, Ryouichi; Kojima, Takao

    2006-01-01

    The characteristics of the far-infrared light source using the coherent radiation emitted from a high-energy short electron bunch have been investigated. The coherent radiation has a continuous spectrum in a submillimeter to millimeter wavelength range and the brightness is relatively high. The spectrum of the radiation is determined by the longitudinal form factor of the electron bunch. The operational conditions of a high-current linear accelerator have been optimized using an electron bunch shape monitor. The coherent transition radiation light source has been applied to absorption spectroscopy for liquid water and to an imaging experiment for a leaf of rose

  13. Accelerating execution of the integrated TIGER series Monte Carlo radiation transport codes

    Science.gov (United States)

    Smith, L. M.; Hochstedler, R. D.

    1997-02-01

    Execution of the integrated TIGER series (ITS) of coupled electron/photon Monte Carlo radiation transport codes has been accelerated by modifying the FORTRAN source code for more efficient computation. Each member code of ITS was benchmarked and profiled with a specific test case that directed the acceleration effort toward the most computationally intensive subroutines. Techniques for accelerating these subroutines included replacing linear search algorithms with binary versions, replacing the pseudo-random number generator, reducing program memory allocation, and proofing the input files for geometrical redundancies. All techniques produced identical or statistically similar results to the original code. Final benchmark timing of the accelerated code resulted in speed-up factors of 2.00 for TIGER (the one-dimensional slab geometry code), 1.74 for CYLTRAN (the two-dimensional cylindrical geometry code), and 1.90 for ACCEPT (the arbitrary three-dimensional geometry code).

  14. Accelerating execution of the integrated TIGER series Monte Carlo radiation transport codes

    International Nuclear Information System (INIS)

    Smith, L.M.; Hochstedler, R.D.

    1997-01-01

    Execution of the integrated TIGER series (ITS) of coupled electron/photon Monte Carlo radiation transport codes has been accelerated by modifying the FORTRAN source code for more efficient computation. Each member code of ITS was benchmarked and profiled with a specific test case that directed the acceleration effort toward the most computationally intensive subroutines. Techniques for accelerating these subroutines included replacing linear search algorithms with binary versions, replacing the pseudo-random number generator, reducing program memory allocation, and proofing the input files for geometrical redundancies. All techniques produced identical or statistically similar results to the original code. Final benchmark timing of the accelerated code resulted in speed-up factors of 2.00 for TIGER (the one-dimensional slab geometry code), 1.74 for CYLTRAN (the two-dimensional cylindrical geometry code), and 1.90 for ACCEPT (the arbitrary three-dimensional geometry code)

  15. Compilation of radiation damage test data part III: materials used around high-energy accelerators

    CERN Document Server

    Beynel, P; Schönbacher, H; CERN. Geneva

    1982-01-01

    For pt.II see CERN report 79-08 (1979). This handbook gives the results of radiation damage tests on various engineering materials and components intended for installation in radiation areas of the CERN high-energy particle accelerators. It complements two previous volumes covering organic cable-insulating materials and thermoplastic and thermosetting resins.

  16. Radiation vulcanization of natural rubber latex with low energy accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Emdadul; Makuuchi, Keizo; Ikeda, Kenichi; Yoshii, Fumio; Kume Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Department of Biological and Chemical Engineering, Kiryu, Gunma (Japan)

    2001-03-01

    The radiation vulcanization of natural rubber latex (RVNRL) with the recently installed electron beam (EB) pilot plant at Takasaki Radiation Chemistry Research Establishment, Takasaki, Japan has been discussed. The accelerating voltage and beam current of the plant are 250 kV and 10 mA respectively. The plant has a reaction vessel with the capacity of 18 liters latex to irradiate at a time. In order to obtain a suitable setting of experimental for RVNRL under EB of the plant the parameters such as irradiation time, defoamer concentration, volume of latex, beam current etc. are being optimized by varying the individual parameter at a constant set of the other variables. (author)

  17. Coherent synchrotron radiation by an electron linear accelerator

    International Nuclear Information System (INIS)

    Nakazato, T.; Oyamada, M.; Niimura, N.

    1990-01-01

    Coherent effects in synchrotron radiation (SR) have been observed for the first time from 180 MeV short electron bunches of 1.7 mm using the Tohoku 300 MeV Linac. The intensity of the coherent SR was about 10 5 times as strong as that of incoherent SR at wavelengths of 0.33 to 2.0 mm. This enhancement factor roughly corresponds to the number of electrons in a bunch. The SR intensity showed a quadratic dependence on the electron beam current. The radiation was mainly polarized in the orbital plane. The possibility of induced rf in a vacuum chamber was excluded experimentally. An electron linear accelerator will be applied to a strong light source from infrared to millimeter wavelengths instead of the storage rings. The bunch length of shorter than 1 mm can be observed by the spectrum measurement of coherent SR. (author)

  18. On the origin of very-high-energy photons in astrophysics: a short introduction to acceleration and radiation physics

    International Nuclear Information System (INIS)

    Lemoine, M.; Pelletier, G.

    2015-01-01

    Powerful astrophysical sources produce non-thermal spectra of very-high-energy photons, with generic power-law distributions, through various radiative processes of charged particles, e.g., synchrotron radiation, inverse Compton processes, and hadronic interactions. Those charged particles have themselves been accelerated to ultra-relativistic energies in intense electromagnetic fields in the source. In many cases, the exact acceleration scheme is not known, but standard scenarios, such as Fermi mechanisms and reconnection processes are generally considered as prime suspects for the conversion of bulk kinetic or electromagnetic energy into a power law of supra-thermal particles. This paper proposes a short introduction to the various acceleration and radiative processes which shape the distributions of very-high-energy photons (E > 100 MeV) in astrophysics. (authors)

  19. Radiation-induced mucositis pain in laryngeal cancer

    International Nuclear Information System (INIS)

    Takahashi, Atsuhito; Shoji, Kazuhiko; Iki, Takehiro; Mizuta, Masanobu; Matsubara, Mami

    2009-01-01

    Radiation therapy in those with head and neck malignancies often triggers painful mucositis poorly controlled by nonsteroidal antiinflammatory drugs (NSAIDs). To better understand how radiation-induced pain develops over time, we studied the numerical rating scale (NRS 0-5) pain scores from 32 persons undergoing radiation therapy of 60-72 Gy for newly diagnosed laryngeal cancer. The degree of mucositis was evaluated using Common Terminology Criteria for Adverse Events version3.0 (CTCAE v3.0). We divided the 32 into a conventional fractionation (CF) group of 14 and a hyperfractionation (HF) group of 18, and further divided laryngeal cancer into a small-field group of 23 and a large-field group of 9. The mucositis pain course was similar in CF and HF, but mucositis pain was severer in the HF group, which also required more NSAIDs. Those in the large-field group had severer pain and mucositis and required more NSAIDs than those in the small-field group. We therefore concluded that small/large-field radiation therapy, rather fractionation type, was related to the incidence of radiation-induced mucositis pain. (author)

  20. Radiation protection challenges in the management of radioactive waste from high-energy accelerators.

    Science.gov (United States)

    Ulrici, Luisa; Algoet, Yvon; Bruno, Luca; Magistris, Matteo

    2015-04-01

    The European Laboratory for Particle Physics (CERN) has operated high-energy accelerators for fundamental physics research for nearly 60 y. The side-product of this activity is the radioactive waste, which is mainly generated as a result of preventive and corrective maintenance, upgrading activities and the dismantling of experiments or accelerator facilities. Prior to treatment and disposal, it is common practice to temporarily store radioactive waste on CERN's premises and it is a legal requirement that these storage facilities are safe and secure. Waste treatment typically includes sorting, segregation, volume and size reduction and packaging, which will depend on the type of component, its chemical composition, residual activity and possible surface contamination. At CERN, these activities are performed in a dedicated waste treatment centre under the supervision of the Radiation Protection Group. This paper gives an overview of the radiation protection challenges in the conception of a temporary storage and treatment centre for radioactive waste in an accelerator facility, based on the experience gained at CERN. The CERN approach consists of the classification of waste items into 'families' with similar radiological and physical-chemical properties. This classification allows the use of specific, family-dependent techniques for radiological characterisation and treatment, which are simultaneously efficient and compliant with best practices in radiation protection. The storage was planned on the basis of radiological and other possible hazards such as toxicity, pollution and fire load. Examples are given of technical choices for the treatment and radiological characterisation of selected waste families, which could be of interest to other accelerator facilities. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. The hypothesis of radiation-accelerated aging and the mortality of Japanese A-bomb victims

    International Nuclear Information System (INIS)

    Beebe, G.W.; Land, C.E.; Kato, H.

    1978-01-01

    The hypothesis that ionizing radiation accelerates aging is extremely difficult to investigate in man except at the level of mortality. Among the 82000 Japanese A-bomb survivors being followed for mortality, there were 14400 deaths from non-neoplastic diseases from October 1950 to September 1974, and this experience has been analysed for evidence of a non-specific mortality differential associated with radiation dose (kerma). Cause of death has been classified as follows: neoplastic diseases individually and in various groupings, tuberculosis, cerebrovascular diseases, cardiovascular diseases other than cerebrovascular, diseases of blood and blood-forming organs, diseases of the digestive system, all other non-neoplastic diseases, and all non-neoplastic diseases. Although there is clear evidence of a radiation effect for many forms of cancer, mortality from other diseases contains little suggestion of a relationship to radiation dose. A superficial association between mortality from diseases of blood and blood-forming organs and radiation rests entirely on the carcinogenic effect of radiation, especially the leukaemogenic effect. Deaths from digestive diseases seem related to radiation dose but only in the 1971-74 period and among the Hiroshima survivors; the excess is small but occurred in all age groups. Thus far the mortality experience of the Japanese A-bomb survivors suggests that the life-shortening effect of whole-body human exposure to ionizing radiation derives from its carcinogenic effect, not from any acceleration of the aging process

  2. Radiation therapy in Ewing's sarcoma: an update of the CESS 86 trial

    International Nuclear Information System (INIS)

    Dunst, Juergen; Juergens, Herbert; Sauer, Rolf; Pape, Hildegard; Paulussen, Michael; Winkelmann, Winfried; Ruebe, Christian

    1995-01-01

    results (5-year overall survival of definitively irradiated patients 63% after conventional fractionation and 65% after hyperfractionation; relapse-free survival 53% vs. 58%; local control 76% vs. 86%, not significant). The six local failures after radiotherapy did not correlate with tumor size or response to chemotherapy. Radiation treatment quality (target volume, technique, dosage) was evaluated retrospectively and was scored as unacceptable in only 1 out of 44 patients (2%) with definitive radiotherapy. Grade 3-4 complications developed in 4 out of 44 (9%) patients after definitive radiotherapy. Conclusions: Under the given selection criteria for local therapy, radiation therapy yielded relapse-free and overall survival figures comparable to radical surgery. Hyperfractionated split-course irradiation simultaneously with multidrug chemotherapy did not significantly improve local control or survival

  3. Hyperfractionated total body irradiation for bone marrow transplantation. Results in seventy leukemia patients with allogeneic transplants

    International Nuclear Information System (INIS)

    Shank, B.; Chu, F.C.H.; Dinsmore, R.

    1983-01-01

    From May, 1979 to March, 1981, 76 leukemia patients were prepared for bone marrow transplantation (BMT) with a new hyperfractionated total body irradiation (TBI) regimen (1320 cGy in 11 fractions, 3x/day), followed by cyclophosphamide, 60 mg/kg, for two days. Partial lung shielding was done on each treatment, with supplemental electron beam treatments of the chest wall to compensate, and of the testes, a sanctuary site. This regimen was initiated to potentially reduce fatal interstitial pneumonitis as well as decrease leukemic relapse. Overall actuarial survival at 1 year for acute non-lymphocytic leukemia (ANLL) patients is 63%, while relapse-free survival at 1 year is 53%. On the other hand, for acute lymphocytic leukemia (ALL) patients, there is no significant difference between relapse or remission patients with regard to overall survival or relapse-free survival, when relapse is defined as > 5% blasts in the marrow at the time of cytoreduction. Overall actuarial survival at 1 year for ALL is 61% and relapse-free survival is 45% at 1 year. Fatal interstitial pneumonitis has dropped to 18% compared with 50% in our previous single-dose TBI regimen (1000 cGy), in which the same doses of cyclophosphamide were given prior to TBI. In conclusion, not only has fatal interstitial pneumonitis been reduced by hyperfractionation and partial lung blocking, but there may be a survival advantage in ALL patients in relapse, who have a survival equal to that of remission patients. This may indicate a greater cell kill with the higher dose (1320 cGy) attained with this regimen, in these patients with a higher leukemic cell burden

  4. submitter Radiation Protection Studies for CERN LINAC4/SPL Accelerator Complex

    CERN Document Server

    Mauro, Egidio; Silari, Marco

    2009-01-01

    CERN is presently designing a new chain of accelerators to replace the present Proton Synchrotron (PS) complex: a 160 MeV room-temperature H$^-$ linac (Linac4) to replace the present 50 MeV proton linac injector, a 3.5 GeV Superconducting Proton Linac (SPL) to replace the 1.4 GeV PS booster (PSB) and a 50 GeV synchrotron (named PS2) to replace the 26 GeV PS. Linac4 has been funded and the civil engineering work started in October 2008, whilst the SPL is in an advanced stage of design. Beyond injecting into the future 50 GeV PS, the ultimate goal of the SPL is to generate a 4 MW beam for the production of intense neutrino beams. The radiation protection design is driven by the latter requirement. This thesis summarizes the radiation protection studies conducted for Linac4. FLUKA Monte Carlo simulations, complemented by analytical estimates, were performed 1) to evaluate the propagation of neutrons through the waveguide, ventilation and cable ducts placed along the accelerator, 2) to estimate the radiological i...

  5. Electromagnetic Radiation : Variational Methods, Waveguides and Accelerators Including seminal papers of Julian Schwinger

    CERN Document Server

    Milton, Kimball A

    2006-01-01

    This is a graduate level textbook on the theory of electromagnetic radiation and its application to waveguides, transmission lines, accelerator physics and synchrotron radiation. It has grown out of lectures and manuscripts by Julian Schwinger prepared during the war at MIT's Radiation Laboratory, updated with material developed by Schwinger at UCLA in the 1970s and 1980s, and by Milton at the University of Oklahoma since 1994. The book includes a great number of straightforward and challenging exercises and problems. It is addressed to students in physics, electrical engineering, and applied mathematics seeking a thorough introduction to electromagnetism with emphasis on radiation theory and its applications.

  6. Unlimited Energy Gain in the Laser-Driven Radiation Pressure Dominant Acceleration of Ions

    OpenAIRE

    Bulanov, S. V.; Echkina, E. Yu.; Esirkepov, T. Zh.; Inovenkov, I. N.; Kando, M.; Pegoraro, F.; Korn, G.

    2009-01-01

    The energy of the ions accelerated by an intense electromagnetic wave in the radiation pressure dominated regime can be greatly enhanced due to a transverse expansion of a thin target. The expansion decreases the number of accelerated ions in the irradiated region increasing the energy and the longitudinal velocity of remaining ions. In the relativistic limit, the ions become phase-locked with respect to the electromagnetic wave resulting in the unlimited ion energy gain. This effect and the ...

  7. Hyperfractionated radiation in the treatment of squamous cell carcinomas of the head and neck: a comparison of two fractionation schedules

    Energy Technology Data Exchange (ETDEWEB)

    Garden, Adam S; Morrison, William H; Ang, K Kian; Peters, Lester J

    1995-02-01

    Purpose: In 1984 we began treating patients with squamous cell carcinomas of the larynx and hypopharynx with hyperfractionated radiotherapy. Patients received 76.8 Gy in 1.2 Gy fractions twice daily, with a 4 h interfraction interval. In 1988, this schedule was modified in patients treated with shrinking field techniques. The dose per fraction was slightly reduced (while not changing the total dose), and the interfraction interval was increased to 6 h. The goal was to decrease toxicity while maintaining satisfactory local-regional control. This retrospective study analyzes the results of this schedule modification. Methods and Materials: Two hundred thirty-six patients were included in the analysis. Distribution of patients by primary site and T stage was as follows: supraglottic larynx, 120 patients; hypopharynx, 70; true vocal cord, 24; and oropharynx, 22; T1, 5 patients; T2, 118; T3, 93; T4, 19; and Tx, 1. Ninety-nine patients presented with cervical nodal disease. Seventy-eight patients (group A), including 16 treated with induction chemotherapy, were treated throughout with 1.2 Gy fractions twice daily and a 4-h interfraction interval. Subsequently, 158 patients (group B), 57 of whom received chemotherapy, received 1.1 Gy fractions to 55 Gy, and then 1.2 Gy fractions to their boost volumes to 76.6 Gy. The interfraction interval was 6 h. Median follow-up was 91 and 35 months for group A and B, respectively. Results: Two-year actuarial survival, local control, and ultimate local rates were 70%, 75%, and 85%, respectively. Differences between survival rates for group A and group B were not statistically significant, with 2-year rates of 66% and 72%, respectively. Overall local control rates at 2 years were 77% and 74%, respectively, for groups A and B (p = 0.22). However, there was a trend toward inferior results in group B patients with T3 disease (67% at 2 years compared to 76% in group A, p = 0.13). Confluent mucositis and persistent mucositis developed in 52

  8. Radiation shielding analysis of a special linear accelerator for electron beam and X-ray.

    Science.gov (United States)

    Kang, W G; Pyo, S H; Alkhuraiji, T S; Han, B S; Kang, C M

    2017-01-01

    The King AbdulAziz City for Science & Technology in the Kingdom of Saudi Arabia plans to build a 10 MeV, 15 kW linear accelerator (LINAC) for electron beam and X-ray. The accelerator will be supplied by EB Tech, Republic of Korea, and the design and construction of the accelerator building will be conducted in the cooperation with EB Tech. This report presents the shielding analysis of the accelerator building using the Monte Carlo N-Particle Transport Code (MCNP). In order to improve the accuracy in estimating deep radiation penetration and to reduce computation time, various variance reduction techniques, including the weight window (WW) method, the deterministic transport (DXTRAN) spheres were considered. Radiation levels were estimated at selected locations in the shielding facility running MCNP6 for particle histories up to 1.0×10+8. The final results indicated that the calculated doses at all selected detector locations met the dose requirement of 50 mSv/yr, which is the United State Nuclear Regulatory Commission (U.S. NRC) requirement.

  9. Consideration on A.C. electric motor subjected to thermal and radiation accelerated ageing

    International Nuclear Information System (INIS)

    Doina, Segarceanu; Geambau, C.

    2001-01-01

    In the containment building of a nuclear reactor there are many types of equipment, such as motors, valve and transducers. Electric motors used in nuclear power stations operate under specific environmental conditions. These conditions are determinate by temperature, humidity, pressure, radiation and they may be normal conditions in service, or may be accident conditions occur during the postulated LOCA event. The testing of electric motors capability to meet and exceed the required performances under specific operating environmental conditions all along its operating life implies the performing of a sequence of tests in which the environmental conditions are simulated in a accelerated manner followed by accident simulation tests. Simulating the ageing position of the test sequence is more difficult because of the problem of extrapolating the results of short term accelerated laboratory experiments to the long term exposure (up to 30 years) that actually occur in a nuclear plant. Thermally induced ageing is the most frequently used ageing stress and also the most easily. The insulated system of a motor ageing under the influence of temperature and high - energy radiation can suffer important changes in its electro-insulating properties. Thus, by way of accelerated ageing motors are brought under conditions equivalent to those at the end of their service life, in a relatively short time. Accelerated ageing enables a shorting of electric motor performance evaluation time. (author)

  10. Radiation effects at a high power accelerator and applications to advanced energy sources

    International Nuclear Information System (INIS)

    Sommer, W.F.; Garner, F.A.; Brown, R.D.; Wechsler, M.S.

    1989-01-01

    Many materials are exposed to atom-displacing radiation at high-power accelerators such as the Los Alamos Meson Physics Facility (LAMPF). Beam current densities in the 800-MeV proton beam vary from 12.5 mA cm -2 (8 x 10 16 p/cm 2 s) on graphite targets to 20-μA cm -2 (1.3 x 10 14 p/cm 2 s) on metal-alloy windows. High-level radiation damage results from these particle fluxes. As a consequence of secondary-particle generation in targets and windows and low-level beam losses that lead to particle interactions with structural material, various components are exposed to low-level proton fluxes, gamma radiation, and neutron fluxes of 10 6 --10 10 n/cm 2 s. These include vacuum seals and vacuum chambers of stainless steel and aluminum alloys, solid-state devices for control, diagnostic, and data acquisition electronics, closed-loop cooling-water systems, and insulators. Properties of these materials are degraded by the radiation exposure. Studies of LAMPF and other accelerators, however, have produced solutions to materials problems, allowing the machines to operate for acceptable times without failure. Nevertheless, additional improvements are being investigated in order to further improve operational reliability and safety. 25 refs., 3 figs., 3 tabs

  11. Small-sized linear accelerator of 2.5 MeV electrons with a local radiation shield for custom examination of freight transported by motor transport

    International Nuclear Information System (INIS)

    Baklanov, A.V.; Gavrish, Yu.N.; Klinov, A.P.; Krest'yaninov, A.S.; Nikolaev, V.M.; Fomin, L.P.; Linkenbach, H.A.; Geus, G.; Knospel, W.

    2001-01-01

    A new development of a small-sized linear accelerator of 2.5 MeV electrons with a local radiation protection is described. The accelerator is intended for movable facilities of radiation custom of the freight transported by motor transport. Main constructive solutions, mass and dimension characteristics and results of preliminary tests of the accelerator parameters and characteristics of radiation protection are presented [ru

  12. High-energy coherent terahertz radiation emitted by wide-angle electron beams from a laser-wakefield accelerator

    Science.gov (United States)

    Yang, Xue; Brunetti, Enrico; Jaroszynski, Dino A.

    2018-04-01

    High-charge electron beams produced by laser-wakefield accelerators are potentially novel, scalable sources of high-power terahertz radiation suitable for applications requiring high-intensity fields. When an intense laser pulse propagates in underdense plasma, it can generate femtosecond duration, self-injected picocoulomb electron bunches that accelerate on-axis to energies from 10s of MeV to several GeV, depending on laser intensity and plasma density. The process leading to the formation of the accelerating structure also generates non-injected, sub-picosecond duration, 1–2 MeV nanocoulomb electron beams emitted obliquely into a hollow cone around the laser propagation axis. These wide-angle beams are stable and depend weakly on laser and plasma parameters. Here we perform simulations to characterise the coherent transition radiation emitted by these beams if passed through a thin metal foil, or directly at the plasma–vacuum interface, showing that coherent terahertz radiation with 10s μJ to mJ-level energy can be produced with an optical to terahertz conversion efficiency up to 10‑4–10‑3.

  13. Synchrotron radiation laboratories at the Bonn electron accelerators. a status report

    Science.gov (United States)

    Hormes, J.

    1987-07-01

    At the Physikalisches Institut of the University in Bonn experiments with synchrotron radiation were carried out ever since 1962. At the moment (June 1986) all work takes place in the SR-laboratory at the 2.5 GeV synchrotron. A 3.5 GeV stretcher ring (ELSA) is under construction and will come into operation at the end of 1986. This accelerator will also run as a storage ring for synchrotron radiation experiments and a laboratory to be used at this machine is also under consideration. The SR experiments which are carried out in Bonn try to take advantage of the fact that we are still using a high energy synchrotron for our work. Besides basic research also applied work is done using synchrotron radiation even as a production tool for X-ray lithography.

  14. Occupational radiation protection around medical linear accelerators: measurements and semi-analytical approaches

    International Nuclear Information System (INIS)

    Donadille, L.; Derreumaux, S.; Mantione, J.; Robbes, I.; Trompier, F.; Amgarou, K.; Asselineau, B.; Martin, A.

    2008-01-01

    Full text: X-rays produced by high-energy (larger than 6 MeV) medical electron linear accelerators create secondary neutron radiation fields mainly by photonuclear reactions inside the materials of the accelerator head, the patient and the walls of the therapy room. Numerous papers were devoted to the study of neutron production in medical linear accelerators and resulting decay of activation products. However, data associated to doses delivered to workers in treatment conditions are scarce. In France, there are more than 350 external radiotherapy facilities representing almost all types of techniques and designs. IRSN carried out a measurement campaign in order to investigate the variation of the occupational dose according the different encountered situations. Six installations were investigated, associated with the main manufacturers (Varian, Elekta, General Electrics, Siemens), for several nominal energies, conventional and IMRT techniques, and bunker designs. Measurements were carried out separately for neutron and photon radiation fields, and for radiation associated with the decay of the activation products, by means of radiometers, tissue-equivalent proportional counters and spectrometers (neutron and photon spectrometry). They were performed at the positions occupied by the workers, i.e. outside the bunker during treatments, inside between treatments. Measurements have been compared to published data. In addition, semi-empirical analytical approaches recommended by international protocols were used to estimate doses inside and outside the bunkers. The results obtained by both approaches were compared and analysed. The annual occupational effective dose was estimated to about 1 mSv, including more than 50 % associated with the decay of activation products and less than 10 % due to direct exposure to leakage neutrons produced during treatments. (author)

  15. Evaluation of pelletron accelerator facility to study radiation effects on semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, A. P. Gnana; Pushpa, N.; Praveen, K. C.; Naik, P. S.; Revannasiddaiah, D. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore-570006, Karnataka (India)

    2012-06-05

    In this paper we present the comprehensive results on the effects of different radiation on the electrical characteristics of different semiconductor devices like Si BJT, n-channel MOSFETs, 50 GHz and 200 GHz silicon-germanium heterojunction bipolar transistor (SiGe HBTs). The total dose effects of different radiation are compared in the same total dose ranging from 100 krad to 100 Mrad. We show that the irradiation time needed to reach very high total dose can be reduced by using Pelletron accelerator facilities instead of conventional irradiation facilities.

  16. Evaluation of pelletron accelerator facility to study radiation effects on semiconductor devices

    International Nuclear Information System (INIS)

    Prakash, A. P. Gnana; Pushpa, N.; Praveen, K. C.; Naik, P. S.; Revannasiddaiah, D.

    2012-01-01

    In this paper we present the comprehensive results on the effects of different radiation on the electrical characteristics of different semiconductor devices like Si BJT, n-channel MOSFETs, 50 GHz and 200 GHz silicon-germanium heterojunction bipolar transistor (SiGe HBTs). The total dose effects of different radiation are compared in the same total dose ranging from 100 krad to 100 Mrad. We show that the irradiation time needed to reach very high total dose can be reduced by using Pelletron accelerator facilities instead of conventional irradiation facilities.

  17. Application of NCRP REPORT No.151 for evaluating the radiation level at the ambience of megavoltage medical electron linear accelerator treatment room

    International Nuclear Information System (INIS)

    Yang Haiyou; Yu Shui

    2011-01-01

    Objective: The estimation model,on radiation level at the ambience of medical electron linear accelerator treatment rooms, is derived on the basis of NCRP REPORT No.151, which presents the calculation model of shielding design about barrier thicknesses of megavoltage medical electron linear accelerator treatment rooms. Methods: The estimation model comes from NCRP REPORT No.151- S tructural Shielding Design and Evaluation for Megavoltage X-and Gamma-Ray Radiotherapy Facilities , which presents the calculation model of shielding design about megavoltage medical electron linear accelerator treatment rooms, and the dose rate at isocenter replaces the workload, and the occupancy factor and the use factor are forsaken, then the converse deduction is done according to barrier thicknesses of shielding materials. Ultimately, the estimation model, on radiation level at the ambience of medical electron linear accelerator treatment rooms, is derived. Results: It can be regarded as a systematic estimation model for calculating the radiation level at the ambience of medical electron linear accelerator treatment room. Conclusion: The estimation model has certain practical value to evaluate the radiation level at the ambience of medical electron linear accelerator treatment room. (authors)

  18. Photographic film dosimetry for high-energy accelerator radiation

    International Nuclear Information System (INIS)

    Komochkov, M.M.; Salatskaya, M.I.

    1981-01-01

    A technique for personnel photographic film dosimetry (PPFDN) of wide energy spectrum neutrons intended for measuring the effect of accelerating device radiation on personnel is described. Procedures of data measurement and processing as well as corrections to hadron contribution are presented. It is noted that the PPFDN method permits to measure a neutron dose equivalent for personnel in the range from 0.01 to 0.02 up to 100 rem, if the relativistic neutron contribution to a total dose does not exceed 5%. The upper limit of the measured dose reduced several times for a greater contribution of relativistic neutrons to the total dose [ru

  19. Charged particle accelerators for practice

    International Nuclear Information System (INIS)

    Arzumanov, A.A.

    1988-01-01

    Characteristics of some accelerators operating in the world are given, capabilities of accelerator technique are demonstrated. Examples of wide application of accelerators in radiation-chemical technology as well as for defectoscopy of massive metal products and impurity ion implantation when producing semiconductor elements are presented. Works on nuclear filter production are characterized by high efficiency. Wide application of synchrotron radiation is described. Various accelerators can be applied during element analysis in geology, metallurgy, ecology. Application of accelerators ''in particular, cyclotrons for radioisotope production as well as in radiotherapy in medicine appears to be important. An isochronous cyclotron with controlled ion energy, at which applied works concerning a number of considered trends in the field of radiation physics and radiation physical metallurgy, element analysis, radiation resistance of electronic circuits and components are conducted, is in operation at the IYaPh of the Kazakh Academy of Sciences. Production of tallium-201 for cardiologic invstigations deserves a special attention. An electrostatic heavy ion accelerator which allows one to produce the beams of accelerated ions of elements from hydrogen to uranium is under commissioning

  20. Accelerated hypofractionated three-dimensional conformal radiation therapy in the treatment of non-small cell lung cancer

    International Nuclear Information System (INIS)

    Yu Jinming; Zheng Aiqing; Yu Yonghua; Wang Xuetao; Yuan Shuanghu; Han Dali; Li Kunhai

    2005-01-01

    Objective: To evaluate the effect and complication of non-small-cell lung cancer (NSCLC) treated with accelerated hypofractionated three dimensional conforms] radiation therapy (3DCRT). Methods: There were squamous carcinoma 21, adenocarcinoma 7, squamous-adenocarcinoma 4 and other cancer 3. There were 17 stage I and 18 stage II. Thirty-five patients of NSCLC were treated with a dose of 30-48 Gy in 6 or 8 Gy per fraction, 3 times a week. The outcome of these patients Was analyzed. Results: The overall 1-, 2- and 3- Year survival rate was 78.2%, 46.9% and 36.3%, respectively. The 1- and 2-year recurrence-free survival rate was 64.6 % and 39.7 %, respectively. The acute radiation pneumonitis and late lung fibrosis rates were high. Univariate analysis showed that Vm was a significant predictor of acute radiation pneumonitis. Conclusion: Compared with accelerated hypofractionated irradiation, the routine conventional fractionated radiation therapy may be preferred for more patients of NSCLC. (authors)

  1. Neuropsychological Outcome of Children Treated for Standard Risk Medulloblastoma in the PNET4 European Randomized Controlled Trial of Hyperfractionated Versus Standard Radiation Therapy and Maintenance Chemotherapy

    International Nuclear Information System (INIS)

    Câmara-Costa, Hugo; Resch, Anika; Kieffer, Virginie; Lalande, Clémence; Poggi, Geraldina; Kennedy, Colin; Bull, Kim; Calaminus, Gabriele; Grill, Jacques; Doz, François; Rutkowski, Stefan; Massimino, Maura; Kortmann, Rolf-Dieter; Lannering, Birgitta; Dellatolas, Georges; Chevignard, Mathilde

    2015-01-01

    Purpose: In the European HIT-SIOP PNET4 randomized controlled trial, children with standard risk medulloblastoma were allocated to hyperfractionated radiation therapy (HFRT arm, including a partially focused boost) or standard radiation therapy (STRT arm), followed, in both arms, by maintenance chemotherapy. Event-free survival was similar in both arms. Previous work showed that the HFRT arm was associated with worse growth and better questionnaire-based executive function, especially in children <8 years of age at diagnosis. Therefore, the aim of this study was to compare performance-based cognitive outcomes between treatment arms. Methods and Materials: Neuropsychological data were collected prospectively in 137 patients. Using the Wechsler Intelligence Scales, Kaufman Assessment Battery for Children, and Raven's Progressive Matrices, we estimated full-scale intelligence quotient (FSIQ) and, when available, verbal IQ (VIQ), performance IQ (PIQ), working memory index (WMI), and processing speed index (PSI). Results: Among the 137 participants (HFRT arm n=71, STRT arm n=66, 63.5% males), mean (±SD) ages at diagnosis and assessment respectively were 9.3 (±3.2) years of age (40.8% < 8 years of age at diagnosis) and 14.6 (±4.3) years of age. Mean (±SD) FSIQ was 88 (±19), and mean intergroup difference was 3.88 (95% confidence interval: −2.66 to 10.42, P=.24). No significant differences were found in children >8 years of age at diagnosis. In children <8 years of age at diagnosis, a marginally significant trend toward higher VIQ was found in those treated in the HFRT arm; a similar trend was found for PSI but not for PIQ, WMI, or FSIQ (mean intergroup differences were: 12.02 for VIQ [95% CI: 2.37-21.67; P=.02]; 3.77 for PIQ [95% CI: −5.19 to 12.74; P>.10]; 5.20 for WMI [95% CI: −2.07 to 12.47; P>.10]; 10.90 for PSI [95% CI: −1.54 to 23.36; P=.08]; and 5.28 for FSIQ [95% CI: −4.23 to 14.79; P>.10]). Conclusions: HFRT was associated with

  2. Neuropsychological Outcome of Children Treated for Standard Risk Medulloblastoma in the PNET4 European Randomized Controlled Trial of Hyperfractionated Versus Standard Radiation Therapy and Maintenance Chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Câmara-Costa, Hugo, E-mail: hugocamaracosta@gmail.com [National Institute of Health and Medical Research, INSERM U1178, Paris (France); Resch, Anika [University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Kieffer, Virginie [Saint Maurice Hospitals, Saint Maurice (France); Lalande, Clémence [Institut Gustave Roussy, Villejuif (France); Poggi, Geraldina [Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco (Italy); Kennedy, Colin; Bull, Kim [University of Southampton, Faculty of Medicine, Southampton (United Kingdom); Calaminus, Gabriele [Paediatric Oncology, University of Muenster, Muenster (Germany); Grill, Jacques [Institut Gustave Roussy, Villejuif (France); Doz, François [Institut Curie and University Paris Descartes, Sorbonne Paris Cité, Paris (France); Rutkowski, Stefan [University Medical Center Hamburg-Eppendorf, Hamburg (Germany); Massimino, Maura [Fondazione IRCCS, Istituto Nazionale Tumori, Milan (Italy); Kortmann, Rolf-Dieter [Department of Radiation Therapy, University of Leipzig, Leipzig (Germany); Lannering, Birgitta [Paediatric Oncology, University of Gothenburg, Gothenburg (Sweden); Dellatolas, Georges [National Institute of Health and Medical Research, INSERM U1178, Paris (France); Chevignard, Mathilde [Rehabilitation Department for Children With Acquired Neurological Injury, Saint Maurice Hospitals, Saint Maurice, and Sorbonne Universités, UPMC Universités Paris, INSERM CNRS, Paris (France)

    2015-08-01

    Purpose: In the European HIT-SIOP PNET4 randomized controlled trial, children with standard risk medulloblastoma were allocated to hyperfractionated radiation therapy (HFRT arm, including a partially focused boost) or standard radiation therapy (STRT arm), followed, in both arms, by maintenance chemotherapy. Event-free survival was similar in both arms. Previous work showed that the HFRT arm was associated with worse growth and better questionnaire-based executive function, especially in children <8 years of age at diagnosis. Therefore, the aim of this study was to compare performance-based cognitive outcomes between treatment arms. Methods and Materials: Neuropsychological data were collected prospectively in 137 patients. Using the Wechsler Intelligence Scales, Kaufman Assessment Battery for Children, and Raven's Progressive Matrices, we estimated full-scale intelligence quotient (FSIQ) and, when available, verbal IQ (VIQ), performance IQ (PIQ), working memory index (WMI), and processing speed index (PSI). Results: Among the 137 participants (HFRT arm n=71, STRT arm n=66, 63.5% males), mean (±SD) ages at diagnosis and assessment respectively were 9.3 (±3.2) years of age (40.8% < 8 years of age at diagnosis) and 14.6 (±4.3) years of age. Mean (±SD) FSIQ was 88 (±19), and mean intergroup difference was 3.88 (95% confidence interval: −2.66 to 10.42, P=.24). No significant differences were found in children >8 years of age at diagnosis. In children <8 years of age at diagnosis, a marginally significant trend toward higher VIQ was found in those treated in the HFRT arm; a similar trend was found for PSI but not for PIQ, WMI, or FSIQ (mean intergroup differences were: 12.02 for VIQ [95% CI: 2.37-21.67; P=.02]; 3.77 for PIQ [95% CI: −5.19 to 12.74; P>.10]; 5.20 for WMI [95% CI: −2.07 to 12.47; P>.10]; 10.90 for PSI [95% CI: −1.54 to 23.36; P=.08]; and 5.28 for FSIQ [95% CI: −4.23 to 14.79; P>.10]). Conclusions: HFRT was associated with

  3. Accelerated degradation of the D2 protein of photosystem II under ultraviolet radiation

    International Nuclear Information System (INIS)

    Jansen, M.A.K.; Edelman, M.; Greenberg, B.M.; Gaba, V.

    1996-01-01

    The D2 protein of photosystem II is relatively stable in vivo under photosynthetic active radiation, but its degradation accelerates under UVB radiation. Little is known about accelerated D2 protein degradation. We characterized wavelength dependence and sensitivity toward photosystem II inhibitors. The in vivo D2 degradation spectrum resembles the pattern for the rapidly turning over D1 protein of photosystem II, with rates being maximal in the UVB region. We propose that D2 degradation, like D1 degradation, is activated by distinct photosensitizers in the UVB and visible regions of the spectrum. In both wavelength regions, photosystem II inhibitors that are known to be targeted to the D1 protein affect D2 degradation. This suggests that degradation of the two proteins is coupled, D2 degradation being influenced by events occurring at the Q B niche on the D1 protein. (Author)

  4. On-site installation and shielding of a mobile electron accelerator for radiation processing

    International Nuclear Information System (INIS)

    Catana, D.; Panaitescu, J.; Axinescu, S.; Manolache, D.; Matei, C.; Corcodel, C.; Ulmeanu, M..; Bestea, V.

    1995-01-01

    The development of radiation processing of some bulk products, e.g. grains or potatoes, would be sustained if the irradiation had been carried out at the place of storage, i.e. silo. A promising solution is proposed consisting of a mobile electron accelerator, installed on a couple of trucks and traveling from one customer to another. The energy of the accelerated electrons was chosen at 5 MeV, with 10 to 50 kW beam power. The irradiation is possible either with electrons or with bremsstrahlung. A major problem of the above solution is the provision of adequate shielding at the customer, with a minimum investment cost. Plans for a bunker are presented, which houses the truck carrying the radiation head. The beam is vertical downwards, through the truck floor, through a transport pipe and a scanning horn. The irradiation takes place in a pit, where the products are transported through a belt. The belt path is so chosen as to minimize openings in the shielding. Shielding calculations are presented supposing a working regime with 5 MeV bremsstrahlung. Leakage and scattered radiation are taken into account. (orig.)

  5. On-site installation and shielding of a mobile electron accelerator for radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Catana, D. [Institutul de Fizica Atomica, Bucharest (Romania); Panaitescu, J. [Institutul de Fizica Atomica, Bucharest (Romania); Axinescu, S. [Institutul de Fizica Atomica, Bucharest (Romania); Manolache, D. [Institutul de Fizica Atomica, Bucharest (Romania); Matei, C. [Institutul de Fizica Atomica, Bucharest (Romania); Corcodel, C. [Institutul de Fizica Atomica, Bucharest (Romania); Ulmeanu, M.. [Institutul de Fizica Atomica, Bucharest (Romania); Bestea, V. [Institutul de Fizica Atomica, Bucharest (Romania)

    1995-05-01

    The development of radiation processing of some bulk products, e.g. grains or potatoes, would be sustained if the irradiation had been carried out at the place of storage, i.e. silo. A promising solution is proposed consisting of a mobile electron accelerator, installed on a couple of trucks and traveling from one customer to another. The energy of the accelerated electrons was chosen at 5 MeV, with 10 to 50 kW beam power. The irradiation is possible either with electrons or with bremsstrahlung. A major problem of the above solution is the provision of adequate shielding at the customer, with a minimum investment cost. Plans for a bunker are presented, which houses the truck carrying the radiation head. The beam is vertical downwards, through the truck floor, through a transport pipe and a scanning horn. The irradiation takes place in a pit, where the products are transported through a belt. The belt path is so chosen as to minimize openings in the shielding. Shielding calculations are presented supposing a working regime with 5 MeV bremsstrahlung. Leakage and scattered radiation are taken into account. (orig.).

  6. Assessing the Impact of Earth Radiation Pressure Acceleration on Low-Earth Orbit Satellites

    Science.gov (United States)

    Vielberg, Kristin; Forootan, Ehsan; Lück, Christina; Kusche, Jürgen; Börger, Klaus

    2017-04-01

    The orbits of satellites are influenced by several external forces. The main non-gravitational forces besides thermospheric drag, acting on the surface of satellites, are accelerations due to the Earth and Solar Radiation Pres- sure (SRP and ERP, respectively). The sun radiates visible and infrared light reaching the satellite directly, which causes the SRP. Earth also emits and reflects the sunlight back into space, where it acts on satellites. This is known as ERP acceleration. The influence of ERP increases with decreasing distance to the Earth, and for low-earth orbit (LEO) satellites ERP must be taken into account in orbit and gravity computations. Estimating acceler- ations requires knowledge about energy emitted from the Earth, which can be derived from satellite remote sensing data, and also by considering the shape and surface material of a satellite. In this sensitivity study, we assess ERP accelerations based on different input albedo and emission fields and their modelling for the satellite missions Challenging Mini-Satellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE). As input fields, monthly 1°x1° products of Clouds and the Earth's Radiant En- ergy System (CERES), L3 are considered. Albedo and emission models are generated as latitude-dependent, as well as in terms of spherical harmonics. The impact of different albedo and emission models as well as the macro model and the altitude of satellites on ERP accelerations will be discussed.

  7. Radio-chemotherapy in advanced tumors of the oral cavity, oro- and hypopharynx

    International Nuclear Information System (INIS)

    Schmitt, G.; Schnabel, T.

    1992-01-01

    Among combined radio-chemotherapy regimens of advanced head and neck tumors four modalities can be discriminated: 1. Induction chemotherapy, 2. simultaneous radio-chemotherapy, 3. adjuvant chemotherapy, 4. accelerated-hyperfractionated radiotherapy and chemotherapy. The results of the presently available randomized trials are as follows: 1. Induction chemotherapy has no influence on long-term recurrence-free survival. 2. With respect to simultaneous radio-chemotherapy, recurrence-free survival has been unproved with 5-FU and Mitomycin C. 3. There is evidence that adjuvant cis-platin therapy improves recurrence-free survival. 4. No results are available to date using hyperfractionated accelerated radiotherapy regimens in combination with chemotherapy. (orig.) [de

  8. Preoperative hyperfractionated radiotherapy for locally advanced rectal cancers: a phase I-II trial

    International Nuclear Information System (INIS)

    Allal, Abdelkarim S.; Bieri, Sabine; Bruendler, Marie-Anne; Soravia, Claudio; Gertsch, Philippe; Bernier, Jacques; Morel, Philippe; Roth, Arnaud D.

    2002-01-01

    Purpose: To assess the toxicity, pathologic response rates, type of surgery, and oncologic results in a prospective Phase I-II trial using pure hyperfractionated radiotherapy (RT) preoperatively in locally advanced rectal cancer. Methods and Materials: Between September 1997 and April 2000, 50 patients with T3-T4 or N1 rectal cancers were treated preoperatively with 50 Gy (45 Gy to the pelvis and a 5-Gy tumor boost) in 40 fractions of 1.25 Gy during 4 weeks. The pretreatment tumor stage as determined by CT and endorectal ultrasonography (80% of patients) included 1 Stage T2 (2%), 45 T3 (90%), and 4 T4 (8%). Nodal involvement (N1) was documented in 26 patients (52%). Surgery was performed at a median interval of 45 days (range 26-114 days) after RT completion. Seventeen patients who presented with pT4 or pN1 and/or pM1 received 5-fluorouracil-based chemotherapy postoperatively. Results: All patients completed the RT schedule as planned. Severe acute toxicities included two Grade 3 skin reactions (4%) that did not require a break. The other acute toxicities were Grade 2 or less (skin, diarrhea, urinary, rectal tenesmus, and fatigue). A complete pathologic response was observed in 7 patients (14%), and microscopic residual cancer was found in 10 (20%). Of the 20 patients presenting with tumor located ≤6 cm from the anal verge, sphincter-saving surgery was performed in 14 (70%). At 3 years, the actuarial locoregional control rate was 90.5%, and the disease-free survival rate was 74.6%. At a median follow-up of 32 months, 4 patients (8%) presented with severe late complications (Grade 3-4) that might have been RT related (one rectovaginal fistula, two chronic perineal fistulas, and one bilateral ureteral stenosis). Conclusion: In locally advanced rectal cancer, preoperative hyperfractionated RT to a total dose of 50 Gy is feasible, with acceptable acute and late toxicity and an objective downstaging effect. In view of these results, this schedule might be used as a

  9. CAS CERN Accelerator School. Synchrotron radiation and free electron lasers. Proceedings

    International Nuclear Information System (INIS)

    Turner, S.

    1998-01-01

    These proceedings present the lectures given at the tenth specialised course organised by the CERN Accelerator School (CAS), the topic this time being 'Synchrotron Radiation and Free-electron Lasers'. A similar course was already given at Chester, UK in 1989 and whose proceedings were published as CERN 90-03. However, recent progress in this field has been so rapid that it became urgent to present a revised version of the course. Starting with a review of the characteristics of synchrotron radiation there follows introductory lectures on electron dynamics in storage rings, beam insertion devices, and beam current and radiation brightness limits. These themes are then developed with more detailed lectures on lattices and emittance, wigglers and undulators, current limitations, beam lifetime and quality, diagnostics and beam stability. Finally lectures are presented on linac and storage ring free-electron lasers. (orig.)

  10. Constitutive gene expression profile segregates toxicity in locally advanced breast cancer patients treated with high-dose hyperfractionated radical radiotherapy

    International Nuclear Information System (INIS)

    Henríquez Hernández, Luis Alberto; Lara, Pedro Carlos; Pinar, Beatriz; Bordón, Elisa; Gallego, Carlos Rodríguez; Bilbao, Cristina; Pérez, Leandro Fernández; Morales, Amílcar Flores

    2009-01-01

    Breast cancer patients show a wide variation in normal tissue reactions after radiotherapy. The individual sensitivity to x-rays limits the efficiency of the therapy. Prediction of individual sensitivity to radiotherapy could help to select the radiation protocol and to improve treatment results. The aim of this study was to assess the relationship between gene expression profiles of ex vivo un-irradiated and irradiated lymphocytes and the development of toxicity due to high-dose hyperfractionated radiotherapy in patients with locally advanced breast cancer. Raw data from microarray experiments were uploaded to the Gene Expression Omnibus Database http://www.ncbi.nlm.nih.gov/geo/ (GEO accession GSE15341). We obtained a small group of 81 genes significantly regulated by radiotherapy, lumped in 50 relevant pathways. Using ANOVA and t-test statistical tools we found 20 and 26 constitutive genes (0 Gy) that segregate patients with and without acute and late toxicity, respectively. Non-supervised hierarchical clustering was used for the visualization of results. Six and 9 pathways were significantly regulated respectively. Concerning to irradiated lymphocytes (2 Gy), we founded 29 genes that separate patients with acute toxicity and without it. Those genes were gathered in 4 significant pathways. We could not identify a set of genes that segregates patients with and without late toxicity. In conclusion, we have found an association between the constitutive gene expression profile of peripheral blood lymphocytes and the development of acute and late toxicity in consecutive, unselected patients. These observations suggest the possibility of predicting normal tissue response to irradiation in high-dose non-conventional radiation therapy regimens. Prospective studies with higher number of patients are needed to validate these preliminary results

  11. Radiotherapeutic management of non-small cell lung cancer (NSCLC). An overview based on the clinical trials of the radiation therapy oncology group (RTOG)

    International Nuclear Information System (INIS)

    Wilson, J.F.; Byhardt, R.W.

    1995-01-01

    Recent clinical trials clarified the role of radiation therapy (RT) in the treatment of non-small cell lung cancer (NSCLC). The evolution of this research is illustrated by a systemic succession of studies conducted during the last twenty years by the Radiation Therapy Oncology Group (RTOG). This article reviews past and present RTOG research efforts in NSCLC. For unresectable NSCLS, major research themes have included radiation dose intensification using both standard and altered fractionation (hyperfractionation or accelerated fraction RT), treatment intensification using combined modality RT and chemotherapy (CT), as well as noncytotoxic adjuvants to RT. These trials have shown that treatment intensification can yield improved survival with acceptable toxicity. Local control and survival was improved with induction CT followed by standard RT to 60 Gy. Current studies will evaluate the timing and sequencing of CT and RT and the combination of CT with altered fractionation RT. Hypoxic cell sensitizers and nonspecific immune stimulants, two noncytotoxic adjuvants to RT, have shown no survival benefit. Biologic response modifiers, including recombinant interferon-beta, will also be evaluated as adjuvants to standard RT, based on interferon-beta radiosensitization observed in the laboratory and clinical investigations suggesting improved survival. Overall, RTOG studies have demonstrated small, but definite, incremental improvements in treatment outcome in NSCLS and provide a solid foundation on which to develop future investigations. (N.K.) 51 refs

  12. An overview of applications and radiation safety aspects of linear accelerators in Brazilian industry

    International Nuclear Information System (INIS)

    Lourenco, M.J.M.; Silva, F.C.A. da

    2002-01-01

    This work presents a brief description of the situation of Brazilian Regulatory Authority about safety control on Industrial Linear Accelerators Installations. It shows the national regulatory infrastructure responsible for radiation safety inspections, the regulation infrastructure, the national inventory of industrial installations, the national system of inspection and enforcement and the national system for qualifying the radiation protection officer. Some results of regulatory safety inspections are also showed in this work. (author)

  13. Quality control in radiotherapy treatment: Radiation induced myelopathy

    International Nuclear Information System (INIS)

    Fernandez-Vicioso, E.; Ruiz-Cruces, R.

    2001-01-01

    Direct injury of the spinal cord has been reported many times, particularly in cases of overexposures with radiotherapy of neoplasm that occurred outside the Central Nervous System. Permanent damage to the spinal cord is the most feared complication of radiation therapy treatments and one of the relatively common causes of litigation for medical malpractice in the context of cancer treatment. We have learned from clinical experience, data from randomized trials and animal experimentation, the dose tolerance as well as the interfraction interval for hyperfractionation regimes. We are still lacking precious clinical information, in particular the dose tolerance in combined modality treatments that represent the vast majority of modern treatments. (author)

  14. Proposal of experimental facilities for studies of nuclear data and radiation engineering in the Intense Proton Accelerator Project

    CERN Document Server

    Baba, M; Nagai, Y; Ishibashi, K

    2003-01-01

    A proposal is given on the facilities and experiments in the Intense Proton Accelerator Project (J-PARC) relevant to the nuclear data and radiation engineering, nuclear astrophysics, nuclear transmutation, accelerator technology and space technology and so on. (3 refs).

  15. Radiation Field Forming for Industrial Electron Accelerators Using Rare-Earth Magnetic Materials

    Science.gov (United States)

    Ermakov, A. N.; Khankin, V. V.; Shvedunov, N. V.; Shvedunov, V. I.; Yurov, D. S.

    2016-09-01

    The article describes the radiation field forming system for industrial electron accelerators, which would have uniform distribution of linear charge density at the surface of an item being irradiated perpendicular to the direction of its motion. Its main element is non-linear quadrupole lens made with the use of rare-earth magnetic materials. The proposed system has a number of advantages over traditional beam scanning systems that use electromagnets, including easier product irradiation planning, lower instantaneous local dose rate, smaller size, lower cost. Provided are the calculation results for a 10 MeV industrial electron accelerator, as well as measurement results for current distribution in the prototype build based on calculations.

  16. Accelerators for therapy

    International Nuclear Information System (INIS)

    Pohlit, W.

    1994-01-01

    In the past decades circular and linear electron accelerators have been developed for clinical use in radiation therapy of tumors with the aim of achieving a high radiation dose in the tumor and as low as possible dose in the adjacent normal tissues. Today about one thousand accelerators are in medical use throughout the world and many hundred thousand patients are treated every day with accelerator-produced radiation. There exists, however, a large number of patients who cannot be treated satisfactorily in this way. New types of radiations such as neutrons, negative pions, protons and heavy ions were therefore tested recently. The clinical experience with these radiations and with new types of treatment procedures indicate that in future the use of a scanning beam of high energy protons might be optimal for the treatment of tumors. (orig.)

  17. OPserver: opacities and radiative accelerations on demand

    Science.gov (United States)

    Mendoza, C.; González, J.; Seaton, M. J.; Buerger, P.; Bellorín, A.; Meléndez, M.; Rodríguez, L. S.; Delahaye, F.; Zeippen, C. J.; Palacios, E.; Pradhan, A. K.

    2009-05-01

    We report on developments carried out within the Opacity Project (OP) to upgrade atomic database services to comply with e-infrastructure requirements. We give a detailed description of an interactive, online server for astrophysical opacities, referred to as OPserver, to be used in sophisticated stellar modelling where Rosseland mean opacities and radiative accelerations are computed at every depth point and each evolution cycle. This is crucial, for instance, in chemically peculiar stars and in the exploitation of the new asteroseismological data. OPserver, downloadable with the new OPCD_3.0 release from the Centre de Données Astronomiques de Strasbourg, France, computes mean opacities and radiative data for arbitrary chemical mixtures from the OP monochromatic opacities. It is essentially a client-server network restructuring and optimization of the suite of codes included in the earlier OPCD_2.0 release. The server can be installed locally or, alternatively, accessed remotely from the Ohio Supercomputer Center, Columbus, Ohio, USA. The client is an interactive web page or a subroutine library that can be linked to the user code. The suitability of this scheme in grid computing environments is emphasized, and its extension to other atomic database services for astrophysical purposes is discussed.

  18. Radiation belt electron acceleration during the 17 March 2015 geomagnetic storm: Observations and simulations

    International Nuclear Information System (INIS)

    Li, W.; Ma, Q.; Thorne, R. M.; Bortnik, J.; Zhang, X.-J.

    2016-01-01

    Various physical processes are known to cause acceleration, loss, and transport of energetic electrons in the Earth's radiation belts, but their quantitative roles in different time and space need further investigation. During the largest storm over the past decade (17 March 2015), relativistic electrons experienced fairly rapid acceleration up to ~7 MeV within 2 days after an initial substantial dropout, as observed by Van Allen Probes. In the present paper, we evaluate the relative roles of various physical processes during the recovery phase of this large storm using a 3-D diffusion simulation. By quantitatively comparing the observed and simulated electron evolution, we found that chorus plays a critical role in accelerating electrons up to several MeV near the developing peak location and produces characteristic flat-top pitch angle distributions. By only including radial diffusion, the simulation underestimates the observed electron acceleration, while radial diffusion plays an important role in redistributing electrons and potentially accelerates them to even higher energies. Moreover, plasmaspheric hiss is found to provide efficient pitch angle scattering losses for hundreds of keV electrons, while its scattering effect on > 1 MeV electrons is relatively slow. Although an additional loss process is required to fully explain the overestimated electron fluxes at multi-MeV, the combined physical processes of radial diffusion and pitch angle and energy diffusion by chorus and hiss reproduce the observed electron dynamics remarkably well, suggesting that quasi-linear diffusion theory is reasonable to evaluate radiation belt electron dynamics during this big storm.

  19. Radiation-induced segregation in materials: Implications for accelerator-driven neutron source applications

    Energy Technology Data Exchange (ETDEWEB)

    Faulkner, R.B.; Song, S. [Loughborough Univ. of Technology (United Kingdom)

    1995-10-01

    This paper reviews exisiting models for radiation-induced segregation to microstrucural interfaces and surfaces. It indicates how the models have been successfully used in the past in neutron irradiation situations and how they may be modified to account for accelerator-driven RIS. The predictions of the models suggest that any impurity with large misfit will suffer RIS and that the effect is heightened as radiation damage increases. The paper suggests methods to utilise the RIS in transmutation technology by dynamically segregating long life nuclides to preferred sites in the microstructure so that subsequent transmutations occur with maximum efficiency.

  20. Electron accelerators for waste processing

    International Nuclear Information System (INIS)

    Kon'kov, N.G.

    1976-01-01

    The documents of the International symposium on radiation vaste processing are presented. Questions on waste utilization with the help of electron accelerators are considered. The electron accelerators are shown to have an advantage over some other ionizing radiation sources. A conclusion is made that radiation methods of waste processing are extensively elaborated in many developed countries. It has been pointed out that an electron accelerator is a most cheap and safe ionizing radiation source primarily for processing of gaseous and liquid wastes

  1. Evaluation of area monitor response for neutrons in radiation field generated by a 15 MV clinic accelerator

    International Nuclear Information System (INIS)

    Salgado, Ana Paula

    2011-01-01

    The clinical importance and usage of linear accelerators in cancer treatment increased significantly in the last years. Coupled with this growth came the concern about the use of accelerators with energies over to 10 MeV which produce therapeutic beam contaminated with neutrons generated when high-energy photons interact with high-atomic-number materials such as tungsten and lead present in the accelerator itself. At these facilities, measurements of the ambient dose equivalent for neutrons present difficulties owing to the existence of a mixed radiation field and possible electromagnetic interference near the accelerator. The Neutron Laboratory of the IRD - Brazilian Institute for Radioprotection and Dosimetry, aiming to evaluate the survey meters performance at these facilities, initiated studies of instrumentation response in the presence of different neutron spectra. Neutrons sources with average energies ranging from 0.55 to 4.2 MeV, four different survey meters and one ionization chamber to obtain the ratio between the dose due to neutrons and gamma radiation were used in this work. The evaluation of these measurements, performed in a 15 MV linear accelerator room is presented. This work presents results that demonstrate the complexity and care needed to make neutrons measurements in radiotherapy treatment rooms containing high energy clinical accelerators. (author)

  2. Accelerator development for medical applications

    International Nuclear Information System (INIS)

    Tanabe, Eiji

    2007-01-01

    Electron linear accelerators have been widely used in medical applications, especially in radiation therapy for cancer treatment. There are more than 7,000 medical electron linear accelerators in the world, treating over 250,000 patients per day. This paper reviews the current status of accelerator applications and technologies in radiation therapy, and presents the anticipated requirements for advanced radiation therapy technology in the foreseeable future. (author)

  3. Economic evaluation of slurry-, sewage-sludge, and crop disinfection facility applications based on industrial accelerator and 60Co radiation source

    International Nuclear Information System (INIS)

    Abelovszky, L.

    1979-01-01

    The degree of the compliance with the requirements of slurry and sewage treatment, the range of use of radiation sterilization procedures in agriculture and food industry, the possibilities of the complex application of radiation methods and factors influencing their economic efficiency, the economic evaluation of the versatile chargeable accelerators, the fixed and semi-mobile radioisotope facilities, the economic efficiency of the multipurpose utilization, the differences in the application of accelerators and radio isotopes as to the power source applied, the penetration, the dose rates and the radiation energy focusing are discussed. The radiation facility costs are compared. Conclusions concerning the choice of the most efficient applications are given. (author)

  4. Study on pulsed radiation generation in the accelerator AKVAGEN; Issledovanie po generatsii impul`sa izlucheniya uskoritelya AKVAGEN

    Energy Technology Data Exchange (ETDEWEB)

    Bakulin, Yu P [and others

    1994-12-31

    The pulse accelerator AKVAGEN is created according to a circuit of as single forming line, charged from two pulse transformers up to 1.5 voltage. Typical irradiation levels are presented. The accelerator x radiation efficiency calculated makes up for Si and SiC, SiO{sub 2}, GaAs compounds.

  5. Analysis of late complications after rapid hyperfractionated radiotherapy in advanced head and neck cancers

    International Nuclear Information System (INIS)

    Nguyen, T.D.; Panis, X.; Froissart, D.; Legros, M.; Coninx, P.; Loirette, M.

    1988-01-01

    Late effects were analyzed in a series of 39 patients with a 2-year minimal follow-up who were treated by rapid hyperfractionated radiotherapy. The total dose was 66-72 Gy delivered in two series of 33-36 Gy separated by a 2-4 week rest interval. The number of daily fractions ranged from 8 to 6 and the interval between each fraction was 2 hr. Late complications consisted of cervical fibrosis, mucosal necrosis, bone necrosis, trismus, and laryngeal edema. Seventy percent of patients experienced late complications, and in 54% of cases, these reactions were considered severe, causing death in 13% of patients. No relationship was found between field sizes, dosimetric data and type and frequency of late effects. It is therefore suggested that the interval between two daily sessions in any multifractionated protocol may be of critical importance

  6. Resistance to ionizing radiations of materials installed at the CERN accelerators

    International Nuclear Information System (INIS)

    Schoenbacher, H.

    1982-01-01

    All materials installed in high energy accelerators along the lines of primary and secondary beams are exposed to ionizing radiation. This can in certain cases cause a degradation of the properties of these materials and consequently affect the good function of the installation. The author has taken at CERN large number of samples of materials in order to determine their radioresistance. Generally the organic materials and the electronic components are more sensitive to ionizing radiation. The author presents the results of these studies which concern the isolations of the cables (polyethylene, polyvinyl chloride, caoutchouc ethylene propylene, etc.), the isolations for the magnets on the base of epoxy resins, as well as other thermoresistant and thermoplastic products. The author equally presents a choice of materials and components which are used at CERN and which are resistant to radiations above an integral dose of 10 7 -10 8 Gy. (orig.)

  7. Radiation therapy with laser-driven accelerated particle beams: physical dosimetry and spatial dose distribution

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, Sabine; Assmann, Walter [Ludwig-Maximilians Universitaet Muenchen (Germany); Kneschaurek, Peter; Wilkens, Jan [MRI, Technische Universitaet Muenchen (Germany)

    2011-07-01

    One of the main goals of the Munich Centre for Advanced Photonics (MAP) is the application of laser driven accelerated (LDA) particle beams for radiation therapy. Due to the unique acceleration process ultrashort particle pulses of high intensity (> 10{sup 7} particles /cm{sup 2}/ns) are generated, which makes online detection an ambitious task. So far, state of the art detection of laser accelerated ion pulses are non-electronic detectors like radiochromic films (RCF), imaging plates (IP) or nuclear track detectors (e.g. CR39). All these kind of detectors are offline detectors requiring several hours of processing time. For this reason they are not qualified for an application in radiation therapy where quantitative real time detection of the beam is an essential prerequisite. Therefore we are investigating pixel detectors for real time monitoring of LDA particle pulses. First tests of commercially available systems with 8-20 MeV protons are presented. For radiobiological experiments second generation Gafchromic films (EBT2) have been calibrated with protons of 12 and 20 MeV for a dose range of 0.3-10 Gy. Dose verification in proton irradiation of subcutaneous tumours in mice was successfully accomplished using these films.

  8. Ten scenarios from early radiation to late time acceleration with a minimally coupled dark energy

    Energy Technology Data Exchange (ETDEWEB)

    Fay, Stéphane, E-mail: steph.fay@gmail.com [Palais de la Découverte, Astronomy Department, Avenue Franklin Roosevelt, 75008 Paris (France)

    2013-09-01

    We consider General Relativity with matter, radiation and a minimally coupled dark energy defined by an equation of state w. Using dynamical system method, we find the equilibrium points of such a theory assuming an expanding Universe and a positive dark energy density. Two of these points correspond to classical radiation and matter dominated epochs for the Universe. For the other points, dark energy mimics matter, radiation or accelerates Universe expansion. We then look for possible sequences of epochs describing a Universe starting with some radiation dominated epoch(s) (mimicked or not by dark energy), then matter dominated epoch(s) (mimicked or not by dark energy) and ending with an accelerated expansion. We find ten sequences able to follow this Universe history without singular behaviour of w at some saddle points. Most of them are new in dark energy literature. To get more than these ten sequences, w has to be singular at some specific saddle equilibrium points. This is an unusual mathematical property of the equation of state in dark energy literature, whose physical consequences tend to be discarded by observations. This thus distinguishes the ten above sequences from an infinity of ways to describe Universe expansion.

  9. Ten scenarios from early radiation to late time acceleration with a minimally coupled dark energy

    International Nuclear Information System (INIS)

    Fay, Stéphane

    2013-01-01

    We consider General Relativity with matter, radiation and a minimally coupled dark energy defined by an equation of state w. Using dynamical system method, we find the equilibrium points of such a theory assuming an expanding Universe and a positive dark energy density. Two of these points correspond to classical radiation and matter dominated epochs for the Universe. For the other points, dark energy mimics matter, radiation or accelerates Universe expansion. We then look for possible sequences of epochs describing a Universe starting with some radiation dominated epoch(s) (mimicked or not by dark energy), then matter dominated epoch(s) (mimicked or not by dark energy) and ending with an accelerated expansion. We find ten sequences able to follow this Universe history without singular behaviour of w at some saddle points. Most of them are new in dark energy literature. To get more than these ten sequences, w has to be singular at some specific saddle equilibrium points. This is an unusual mathematical property of the equation of state in dark energy literature, whose physical consequences tend to be discarded by observations. This thus distinguishes the ten above sequences from an infinity of ways to describe Universe expansion

  10. QALMA: A computational toolkit for the analysis of quality protocols for medical linear accelerators in radiation therapy

    Science.gov (United States)

    Rahman, Md Mushfiqur; Lei, Yu; Kalantzis, Georgios

    2018-01-01

    Quality Assurance (QA) for medical linear accelerator (linac) is one of the primary concerns in external beam radiation Therapy. Continued advancements in clinical accelerators and computer control technology make the QA procedures more complex and time consuming which often, adequate software accompanied with specific phantoms is required. To ameliorate that matter, we introduce QALMA (Quality Assurance for Linac with MATLAB), a MALAB toolkit which aims to simplify the quantitative analysis of QA for linac which includes Star-Shot analysis, Picket Fence test, Winston-Lutz test, Multileaf Collimator (MLC) log file analysis and verification of light & radiation field coincidence test.

  11. Hyperfractionated accelerated radiation therapy plus cetuximab plus cisplatin chemotherapy in locally advanced inoperable squamous cell carcinoma of the head and neck. Final 5-year results of a phase II study

    Energy Technology Data Exchange (ETDEWEB)

    Kuhnt, Thomas [University of Leipzig, Department of Imaging and Radiation Medicine, Clinic of Radiooncology, Leipzig (Germany); Schreiber, Andreas [Private Praxis for Radio Oncology Dresden, Dresden (Germany); Pirnasch, Anett [University of Rostock, Department of Radiation Oncology, Rostock (Germany); Hautmann, Matthias G. [University of Regensburg, Department of Radiotherapy, Regensburg (Germany); Hass, Peter [Otto von Guericke University of Magdeburg, Department of Radiotherapy, Magdeburg (Germany); Sieker, Frank P. [Martin Luther University of Halle-Wittenberg, Department of Radiotherapy, Halle (Saale) (Germany); Engenhart-Cabillic, Rita [Philipps University Marburg, Department of Radiotherapy, Marburg (Germany); Richter, Michael [Coordination Centre for Clinical Trials Halle, Halle (Saale) (Germany); Dellas, Kathrin; Dunst, Juergen [University of Kiel, Department of Radiation Oncology, Kiel (Germany)

    2017-09-15

    Cetuximab (CET) is a potent inhibitor of the epidermal growth factor receptor and has been shown to have activity in squamous cell carcinoma of the head and neck (SCCHN). We conducted a single-arm phase II trial of a combination therapy comprising cisplatin (CIS), CET and hyperfractionated accelerated radiotherapy (HART). Patients with UICC stage III or IVA/B, M0 SCCHN were enrolled and treated with an initial dose of CET (400 mg/m{sup 2}) and then with a weekly dosage of 250 mg/m{sup 2} during HART. HART was started with a prescribed dosage of 2.0 Gy per day for 3 weeks, followed by 1.4 Gy twice daily to a total dose of 70.6 Gy to the gross tumour volume. CIS (40 mg/m{sup 2}) was administered weekly (days 1, 8, 15, 22, 29 and 36). The primary objective of the phase II study was to determine the 2-year progression-free survival (PFS). Between November 2007 and November 2010, a total of 74 patients were enrolled in the study, of whom 65 were evaluable (83% were men). Median age was 56 years (range 37-69 years). An Oropharyngeal primary tumour was diagnosed in 49%, T4a,b in 65% and N2/3 in 96% of the patients. Of these patients, 85% were smokers or ex-smokers. Complete remission (CR) was observed in 23 patients (35%). The most common toxicity grade was ≥3, including mucositis (58%) and dysphagia (52%). The 2- and 5-year overall survival rates were 64 and 41%, the 2- and 5-year PFS rates were 45 and 32%, and the 2- and 5-year locoregional control rates were 47 and 33%, respectively. The combination of weekly CIS with HART plus CET is a feasible regimen for these unfavourable smoking-induced cancers. However, the parallel US study (RTOG 0522) showed no advantage of the enhanced triple therapy compared to chemoradiotherapy alone. (orig.) [German] Cetuximab (CET) ist ein potenter Inhibitor des epidermalen Wachstumsfaktor-Rezeptors, der schon bei Plattenepithelkarzinomen des Kopf-Hals-Bereichs (SCCHN) Wirkung gezeigt hat. Wir fuehrten eine prospektive, einarmige Phase

  12. Accelerated regression of brain metastases in patients receiving whole brain radiation and the topoisomerase II inhibitor, lucanthone

    International Nuclear Information System (INIS)

    Rowe, John D. del; Bello, Jacqueline; Mitnick, Robin; Sood, Brij; Filippi, Christopher; Moran, Justin Ph.D.; Freeman, Katherine; Mendez, Frances; Bases, Robert

    1999-01-01

    Purpose: To determine if lucanthone crossed the blood-brain barrier in experimental animals; and to determine accelerated tumor regression of human brain metastases treated jointly with lucanthone and whole brain radiation. Methods and Materials: The organ distribution of 3 H lucanthone in mice and 125 I lucanthone in rats was determined to learn if lucanthone crossed the blood-brain barrier. Size determinations were made of patients' brain metastases from magnetic resonance images or by computed tomography before and after treatment with 30 Gy whole brain radiation alone or with lucanthone. Results: The time course of lucanthone's distribution in brain was identical to that in muscle and heart after intraperitoneal or intravenous administration in experimental animals. Lucanthone, therefore, readily crossed the blood-brain barrier in experimental animals. Conclusion: Compared with radiation alone, the tumor regression in patients with brain metastases treated with lucanthone and radiation was accelerated, approaching significance using a permutation test at p = 0.0536

  13. There is no role for hyperfractionated radiotherapy in the management of children with newly diagnosed diffuse intrinsic brainstem tumors: results of a pediatric oncology group phase III trial comparing conventional vs. hyperfractionated radiotherapy

    International Nuclear Information System (INIS)

    Mandell, Lynda R.; Kadota, Richard; Freeman, Carolyn; Douglass, Edwin C.; Fontanesi, James; Cohen, Michael E.; Kovnar, Edward; Burger, Peter; Sanford, Robert A.; Kepner, James; Friedman, Henry; Kun, Larry E.

    1999-01-01

    Purpose: In June 1992, POG began accrual to a phase III study, POG-9239, designed to compare the time to disease progression, overall survival, and toxicities observed in children with newly diagnosed brainstem tumor treated with 100 mg/m 2 of infusional cisplatin and randomized to either conventional vs. hyperfractionated radiotherapy. Methods and Materials: Patients eligible for study were those between 3 and 21 years of age with previously untreated tumors arising in the pons. Histologic confirmation of diagnosis was not mandatory, provided that the clinical and MRI scan findings were typical for a diffusely infiltrating pontine lesion. Treatment consisted of a six-week course of local field radiotherapy with either once a day treatment of 180 cGy per fraction to a total dose of 5400 cGy (arm 1) or a twice a day regimen of 117 cGy per fraction to a total dose of 7020 cGy (the second of the three hyperfractionated dose escalation levels of POG-8495) (arm 2). Because of previously reported poor results with conventional radiotherapy alone, cisplatin was included as a potential radiosensitizer in an attempt to improve progression-free and ultimate survival rates. Based on results of the phase I cisplatin dose escalation trial, POG-9139, 100 mg/m 2 was chosen for this trial and was delivered by continuous infusion over a 120-hour period, beginning on the first day of radiotherapy and repeated during weeks 3 and 5. One hundred thirty eligible patients were treated on protocol, 66 on arm 1 and 64 on arm 2. Results: The results we report are from time of diagnosis through October 1997. For patients treated on arm 1, the median time to disease progression (defined as time to off study) was 6 months (range 2-15 months) and the median time to death 8.5 months (range 3-24 months); survival at 1 year was 30.9% and at 2 years, 7.1%. For patients treated on arm 2, the corresponding values were 5 months (range 1-12 months) and 8 months (range 1-23 months), with 1- and 2-year

  14. Radiation transport code with adaptive Mesh Refinement: acceleration techniques and applications

    International Nuclear Information System (INIS)

    Velarde, Pedro; Garcia-Fernaandez, Carlos; Portillo, David; Barbas, Alfonso

    2011-01-01

    We present a study of acceleration techniques for solving Sn radiation transport equations with Adaptive Mesh Refinement (AMR). Both DSA and TSA are considered, taking into account the influence of the interaction between different levels of the mesh structure and the order of approximation in angle. A Hybrid method is proposed in order to obtain better convergence rate and lower computer times. Some examples are presented relevant to ICF and X ray secondary sources. (author)

  15. Electron accelerators for environmental protection

    International Nuclear Information System (INIS)

    Zimek, Z.

    1998-01-01

    The primary objective of this publication is to provide information suitable for electron accelerators implementation in facilities applying radiation technology for environmental protection. It should be noticed that radiation processing has been successfully used in the fields of crosslinking polymer curing and medical products sterilization for more than 40 years. Practical application of radiation technology today extends on SO 2 and NO x removal from the flue gas (one of major power intensive radiation processing), destruction and removal of organic chemicals from water, decreasing bacteria content in the irradiated sludge and waste water. On the other hand the increased awareness of environmental pollution hazards and more stringent waste regulations in many countries may open stronger support for environmentally oriented technologies. This publication provides an evaluation of electron accelerators capabilities in respect of environmental applications where technological and economical criteria are now well defined. In order to determine the potential of electron accelerators, the literature data were examined as well visits and meetings with various accelerator manufacturers were performed by the author. Experience of the author in accelerator facilities construction and exploitation including those which were used for environmental protection are significant part of this publication. The principle of accelerator action was described in Chapter 1. Early development, accelerator classification and fields of accelerators application were included to this chapter as well. Details of accelerator construction was described in Chapter 2 to illustrate physical capability of accelerators to perform the function of ionizing radiation source. Electron beam extraction devices, under beam equipment, electron beam parameters and measuring methods were characterized in this chapter as well. Present studies of accelerator technology was described in Chapter 3, where

  16. Accelerator shielding benchmark problems

    International Nuclear Information System (INIS)

    Hirayama, H.; Ban, S.; Nakamura, T.

    1993-01-01

    Accelerator shielding benchmark problems prepared by Working Group of Accelerator Shielding in the Research Committee on Radiation Behavior in the Atomic Energy Society of Japan were compiled by Radiation Safety Control Center of National Laboratory for High Energy Physics. Twenty-five accelerator shielding benchmark problems are presented for evaluating the calculational algorithm, the accuracy of computer codes and the nuclear data used in codes. (author)

  17. Distributed Optical Fiber Radiation and Temperature Sensing at High Energy Accelerators and Experiments

    CERN Document Server

    AUTHOR|(CDS)2090137; Brugger, Markus

    The aim of this Thesis is to investigate the feasibility of a distributed optical fiber radiation sensing system to be used at high energy physics accelerators and experiments where complex mixed-field environments are present. In particular, after having characterized the response of a selection of radiation sensitive optical fibers to ionizing radiation coming from a 60Co source, the results of distributed optical fiber radiation measurements in a mixed-field environment are presented along with the method to actually estimate the dose variation. This study demonstrates that distributed optical fiber dosimetry in the above mentioned mixed-field radiation environment is feasible, allowing to detect dose variations of about 10-15 Gy with a 1 m spatial resolution. The proof of principle has fully succeeded and we can now tackle the challenge of an industrial installation taking into account that some optimizations need to be done both on the control unit of the system as well as on the choice of the sensing f...

  18. Coherent transition radiation from a laser wakefield accelerator as an electron bunch diagnostic

    International Nuclear Information System (INIS)

    Tilborg, J. van; Geddes, C.G.R.; Toth, C.; Esarey, E.; Schroeder, C.B.; Martin, M.C.; Hao, Z.; Leemans, W.P.

    2004-01-01

    The observation and modeling of coherent transition radiation from femtosecond laser accelerated electron bunches is discussed. The coherent transition radiation, scaling quadratically with bunch charge, is generated as the electrons transit the plasma-vacuum boundary. Due to the limited transverse radius of the plasma boundary, diffraction effects will strongly modify the angular distribution and the total energy radiated is reduced compared to an infinite transverse boundary. The multi-nC electron bunches, concentrated in a length of a few plasma periods (several tens of microns), experience partial charge neutralization while propagating inside the plasma towards the boundary. This reduces the space-charge blowout of the beam, allowing for coherent radiation at relatively high frequencies (several THz). The charge distribution of the electron bunch at the plasma-vacuum boundary can be derived from Fourier analysis of the coherent part of the transition radiation spectrum. A Michelson interferometer was used to measure the coherent spectrum, and electron bunches with duration on the order of 50 fs (rms) were observed

  19. Solar Passive Modification Increase Radiation Safety Standards Inside Accelerator Building

    International Nuclear Information System (INIS)

    Eid, A. F.; Keshk, A. B.

    2010-01-01

    Irradiation processing by accelerated electrons is considering one of the most important and useful industrial irradiation treatments. It is depending on two principle attachment elements which are architecture of irradiation building and the accelerator characteristic that was arranged inside irradiation building. Negative environmental measurements were recorded inside the main building and were exceeded the international standards (humidity, air speed, high thermal effects and ozone concentration). The study showed that it is essential to improve the natural environmental standards inside the main irradiation building in order to improve the work environment and to reduce ozone concentration from 220 ppb to international standard. The main goals and advantages were achieved by using environmental architecture (desert architecture) indoor the irradiation building. The work depends on passive solar system which is economic, same architectural elements, comfort / health, and radiation safety, and without mechanical means. The experimental work was accomplished under these modifications. The registered results of various environmental concentrations have proved their normal standards.

  20. Acceleration of a Monte Carlo radiation transport code

    International Nuclear Information System (INIS)

    Hochstedler, R.D.; Smith, L.M.

    1996-01-01

    Execution time for the Integrated TIGER Series (ITS) Monte Carlo radiation transport code has been reduced by careful re-coding of computationally intensive subroutines. Three test cases for the TIGER (1-D slab geometry), CYLTRAN (2-D cylindrical geometry), and ACCEPT (3-D arbitrary geometry) codes were identified and used to benchmark and profile program execution. Based upon these results, sixteen top time-consuming subroutines were examined and nine of them modified to accelerate computations with equivalent numerical output to the original. The results obtained via this study indicate that speedup factors of 1.90 for the TIGER code, 1.67 for the CYLTRAN code, and 1.11 for the ACCEPT code are achievable. copyright 1996 American Institute of Physics

  1. Some aspects of radiation protection near high-energy proton accelerators

    CERN Document Server

    Tuyn, Jan Willem Nicolaas

    1977-01-01

    The CERN site near Geneva borders Satigny and Meyrin in Switzerland and Saint-Genis-Pouilly and Prevention in France. The 600 MeV proton synchrocyclotron (SC) has been in operation since 1957, the 28 GeV proton synchrotron (PS) since 1960, and the Intersecting Storage Rings (ISR) since 1971. A fourth large accelerator, the 400 GeV super proton synchrotron (SPS), will soon be in service. The internal and external radiation protection problems caused by these machines, together with the solutions, are reviewed in the light of experience. (5 refs).

  2. A comparison of robotic arm versus gantry linear accelerator stereotactic body radiation therapy for prostate cancer.

    Science.gov (United States)

    Avkshtol, Vladimir; Dong, Yanqun; Hayes, Shelly B; Hallman, Mark A; Price, Robert A; Sobczak, Mark L; Horwitz, Eric M; Zaorsky, Nicholas G

    2016-01-01

    Prostate cancer is the most prevalent cancer diagnosed in men in the United States besides skin cancer. Stereotactic body radiation therapy (SBRT; 6-15 Gy per fraction, up to 45 minutes per fraction, delivered in five fractions or less, over the course of approximately 2 weeks) is emerging as a popular treatment option for prostate cancer. The American Society for Radiation Oncology now recognizes SBRT for select low- and intermediate-risk prostate cancer patients. SBRT grew from the notion that high doses of radiation typical of brachytherapy could be delivered noninvasively using modern external-beam radiation therapy planning and delivery methods. SBRT is most commonly delivered using either a traditional gantry-mounted linear accelerator or a robotic arm-mounted linear accelerator. In this systematic review article, we compare and contrast the current clinical evidence supporting a gantry vs robotic arm SBRT for prostate cancer. The data for SBRT show encouraging and comparable results in terms of freedom from biochemical failure (>90% for low and intermediate risk at 5-7 years) and acute and late toxicity (6 MV). Finally, SBRT (particularly on a gantry) may also be more cost-effective than conventionally fractionated external-beam radiation therapy. Randomized controlled trials of SBRT using both technologies are underway.

  3. Dynamic Monte Carlo simulations of radiatively accelerated GRB fireballs

    Science.gov (United States)

    Chhotray, Atul; Lazzati, Davide

    2018-05-01

    We present a novel Dynamic Monte Carlo code (DynaMo code) that self-consistently simulates the Compton-scattering-driven dynamic evolution of a plasma. We use the DynaMo code to investigate the time-dependent expansion and acceleration of dissipationless gamma-ray burst fireballs by varying their initial opacities and baryonic content. We study the opacity and energy density evolution of an initially optically thick, radiation-dominated fireball across its entire phase space - in particular during the Rph matter-dominated fireballs due to Thomson scattering. We quantify the new phases by providing analytical expressions of Lorentz factor evolution, which will be useful for deriving jet parameters.

  4. Crane RF accelerator for high current radiation damage studies

    International Nuclear Information System (INIS)

    Whitham, K.; Anamkath, H.; Evans, K.; Lyons, S.; Palmer, D.; Miller, R.; Treas, P.; Zante, T.

    1992-01-01

    An electron accelerator was designed and built for the Naval Weapons Support Center for transient radiation effects on electronics experiments and testing. The Crane L Band RF Electron Linac was designed to provide high currents over a wide range of pulse widths and energies. The energy extends to 60 MeV and pulse widths vary from a few ns to 10 μsec. Beam currents range from 20 amps in the short pulse case to 1.5 amps in the long pulse case. This paper describes the linac, its architecture, the e-gun and pulser, waveguides, klystrons and modulator, vacuum system, beam transport, and control systems. fig., tab

  5. Hyperfractionated chemoradiation with carbogen breathing, with or without erythropoietin: A stepwise developed treatment schedule for advanced head-and-neck cancer

    International Nuclear Information System (INIS)

    Martinez, Jose Carlos; Villar, Alfonso; Cabezon, Maria Auxiliadora; Serdio, Jose Luis de; Fuentes, Claudio; Espineira, Manuel; Perez, Maria Dolores; Gil, Jose; Artazkoz, Juan Jose; Borque, Carlos; Suner, Marcos; Saavedra, Juan Antonio

    2001-01-01

    Purpose: To investigate the influence of carbogen breathing on chemoradiation and the effects of erythropoietin on transfusions. Methods and Materials: From March 1996 to April 2000, 42 (4 Stage III and 38 Stage IV) patients with head and neck cancer were treated with a twice-a-day hyperfractionated schedule. Each fraction consisted of 5 mg/m 2 of carboplatin plus 115 cGy with carbogen breathing. Treatment was given 5 days per week up to total doses of 350 mg/m 2 of carboplatin plus 8050 cGy in 7 weeks. Anemia was treated either by transfusion or by erythropoietin. Results: Forty-one patients tolerated the treatment as scheduled. All patients tolerated the planned radiation dose. Five transfusions were given in the first group, but no transfusion was needed in the erythropoietin group. Local toxicities remained at the level expected with irradiation alone. Chemotherapy toxicity was moderate. Forty-two complete responses were achieved. At two years actuarial local control, cause-specific survival and overall survival are respectively 85%, 69%, and 68%. At four years estimated probabilities of local control, cause-specific survival and overall survival are also 85%, 69%, and 68%. Conclusions: These results compare favorably with those of most reported studies. The addition of carbogen breathing appears to improve the results of chemoradiation alone. Erythropoietin therapy avoided transfusions

  6. TU-H-BRA-06: Characterization of a Linear Accelerator Operating in a Compact MRIGuided Radiation Therapy System

    International Nuclear Information System (INIS)

    Green, O; Mutic, S; Li, H; Low, D; Chmielewski, T; Fought, G; Hernandez, M; Kawrakow, I; Sharma, A; Shvartsman, S; Dempsey, J

    2016-01-01

    Purpose: To describe the performance of a linear accelerator operating in a compact MRI-guided radiation therapy system. Methods: A commercial linear accelerator was placed in an MRI unit that is employed in a commercial MR-based image guided radiation therapy (IGRT) system. The linear accelerator components were placed within magnetic field-reducing hardware that provided magnetic fields of less than 40 G for the magnetron, gun driver, and port circulator, with 1 G for the linear accelerator. The system did not employ a flattening filter. The test linear accelerator was an industrial 4 MV model that was employed to test the ability to run an accelerator in the MR environment. An MR-compatible diode detector array was used to measure the beam profiles with the accelerator outside and inside the MR field and with the gradient coils on and off to examine if there was any effect on the delivered dose distribution. The beam profiles and time characteristics of the beam were measured. Results: The beam profiles exhibited characteristic unflattened Bremsstrahlung features with less than ±1.5% differences in the profile magnitude when the system was outside and inside the magnet and less than 1% differences with the gradient coils on and off. The central axis dose rate fluctuated by less than 1% over a 30 second period when outside and inside the MRI. Conclusion: A linaccompatible MR design has been shown to be effective in not perturbing the operation of a commercial linear accelerator. While the accelerator used in the tests was 4MV, there is nothing fundamentally different with the operation of a 6MV unit, implying that the design will enable operation of the proposed clinical unit. Research funding provided by ViewRay, Inc.

  7. TU-H-BRA-06: Characterization of a Linear Accelerator Operating in a Compact MRIGuided Radiation Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Green, O; Mutic, S; Li, H [Washington University School of Medicine, St. Louis, MO (United States); Low, D [University of California, Los Angeles, CA (United States); Chmielewski, T; Fought, G; Hernandez, M; Kawrakow, I; Sharma, A; Shvartsman, S; Dempsey, J [ViewRay, Inc., Oakwood Village, OH (United States)

    2016-06-15

    Purpose: To describe the performance of a linear accelerator operating in a compact MRI-guided radiation therapy system. Methods: A commercial linear accelerator was placed in an MRI unit that is employed in a commercial MR-based image guided radiation therapy (IGRT) system. The linear accelerator components were placed within magnetic field-reducing hardware that provided magnetic fields of less than 40 G for the magnetron, gun driver, and port circulator, with 1 G for the linear accelerator. The system did not employ a flattening filter. The test linear accelerator was an industrial 4 MV model that was employed to test the ability to run an accelerator in the MR environment. An MR-compatible diode detector array was used to measure the beam profiles with the accelerator outside and inside the MR field and with the gradient coils on and off to examine if there was any effect on the delivered dose distribution. The beam profiles and time characteristics of the beam were measured. Results: The beam profiles exhibited characteristic unflattened Bremsstrahlung features with less than ±1.5% differences in the profile magnitude when the system was outside and inside the magnet and less than 1% differences with the gradient coils on and off. The central axis dose rate fluctuated by less than 1% over a 30 second period when outside and inside the MRI. Conclusion: A linaccompatible MR design has been shown to be effective in not perturbing the operation of a commercial linear accelerator. While the accelerator used in the tests was 4MV, there is nothing fundamentally different with the operation of a 6MV unit, implying that the design will enable operation of the proposed clinical unit. Research funding provided by ViewRay, Inc.

  8. ICT accelerators for radiation applications

    Energy Technology Data Exchange (ETDEWEB)

    Wu Shiqin; Chen Dali (Research Inst. of Automation for Machine-Building Industry, Beijing (China))

    Several ICT accelerators were designed and constructed during the past two decades and are now in use in some factories and institutes in various parts of China. The specifications, design considerations, construction specialities and information about the applications of these accelerators are given in the present paper. (author).

  9. Introduction of Parallel GPGPU Acceleration Algorithms for the Solution of Radiative Transfer

    Science.gov (United States)

    Godoy, William F.; Liu, Xu

    2011-01-01

    General-purpose computing on graphics processing units (GPGPU) is a recent technique that allows the parallel graphics processing unit (GPU) to accelerate calculations performed sequentially by the central processing unit (CPU). To introduce GPGPU to radiative transfer, the Gauss-Seidel solution of the well-known expressions for 1-D and 3-D homogeneous, isotropic media is selected as a test case. Different algorithms are introduced to balance memory and GPU-CPU communication, critical aspects of GPGPU. Results show that speed-ups of one to two orders of magnitude are obtained when compared to sequential solutions. The underlying value of GPGPU is its potential extension in radiative solvers (e.g., Monte Carlo, discrete ordinates) at a minimal learning curve.

  10. Complications following linear accelerator based stereotactic radiation for cerebral arteriovenous malformations

    DEFF Research Database (Denmark)

    Skjøth-Rasmussen, Jane; Roed, Henrik; Ohlhues, Lars

    2010-01-01

    Primarily, gamma knife centers are predominant in publishing results on arteriovenous malformations (AVM) treatments including reports on risk profile. However, many patients are treated using a linear accelerator-most of these at smaller centers. Because this setting is different from a large...... gamma knife center, the risk profile at Linac departments could be different from the reported experience. Prescribed radiation doses are dependent on AVM volume. This study details results from a medium sized Linac department center focusing on risk profiles....

  11. Probabilistic safety analysis of radiation treatments with linear accelerator (Spanish Ed.)

    International Nuclear Information System (INIS)

    2012-02-01

    This publication addresses the issue of accidental exposures of radiotherapy patients and how to avoid them. More proactive approaches are required to anticipate and thus avoid situations that could lead to accidental exposures. In this context, the International Atomic Energy Agency (IAEA) and the Ibero American Forum of Radiation and Nuclear and Safety Regulatory Agencies (the FORO) have applied proactive methods, such as probabilistic safety assessment to radiotherapy treatments with accelerators. The methodology and results of this exercise are described in this publication.

  12. Planned High-brightness Channeling Radiation Experiment at Fermilab's Advanced Superconducting Test Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Blomberg, Ben [NICADD, DeKalb; Mihalcea, Daniel [NICADD, DeKalb; Panuganti, Harsha [NICADD, DeKalb; Piot, Philippe [Fermilab; Brau, Charles [Vanderbilt U.; Choi, Bo [Vanderbilt U.; Gabella, William [Vanderbilt U.; Ivanov, Borislav [Vanderbilt U.; Mendenhall, Marcus [Vanderbilt U.; Lynn, Christopher [Swarthmore Coll.; Sen, Tanaji [Fermilab; Wagner, Wolfgang [Forschungszentrum Dresden Rossendorf

    2014-07-01

    In this contribution we describe the technical details and experimental setup of our study aimed at producing high-brightness channeling radiation (CR) at Fermilab’s new user facility the Advanced Superconducting Test Accelerator (ASTA). In the ASTA photoinjector area electrons are accelerated up to 40-MeV and focused to a sub-micron spot on a ~40 micron thick carbon diamond, the electrons channel through the crystal and emit CR up to 80-KeV. Our study utilizes ASTA’s long pulse train capabilities and ability to preserve ultra-low emittance, to produce the desired high average brightness.

  13. Radiation pre-treatment of seed imparts metabolic stability and quality protection during storage under accelerated aging

    International Nuclear Information System (INIS)

    Sumedha; Singh, Bhupinder; Singhal, R.K.

    2014-01-01

    Quality of seed is known to deteriorate due to unfavoured temperature and relative humidity during accelerated aging. Protecting the seed quality during storage is thus a priority challenge for the seed industry till the seeds end up with the end user. Gamma radiation treatment has been shown to improve source to sink transport of photosynthates during terminal heat stress in cereals. An experiment was conducted to measure seed irradiation induced biochemical changes in groundnut cultivar TG-37A stored under accelerated aging at 45±2 ℃ and 95-100 % humidity for 0, 5, 10, 15, 20 and 40 days to aging. The gamma irradiation doses were control (0), 0.005, 0.025, 0.1, 0.5 and 1.0 kGy. Seed samples were periodically evaluated for oil and fatty acid profile by the soxhlet extraction method and gas chromatography mass spectroscopy respectively. Here alike earlier studies variation in fatty acid profile of seed was used as an indicator of seed health under harsh storage conditions of accelerated aging. In the majority of plant species having oil rich seeds, the lipids that are at risk of auto-oxidation contain oleic (18:1), linoleic (18:2) and linolenic (18:3) fatty acid chain. Degree of unsaturation has a significant influence on degree of degradation. Decreased total lipid content in aged sunflower seeds have been reported. Auto-oxidation of unsaturated fatty acids was noticed, especially for linoleic acid in seed of oil crop after seven years of storage. Our results showed radiation treatment did not cause any significant change in oleic (C18:1), linoleic acids (C18:2) and linolenic (C18:3) acid content of seeds. This shows that gamma radiation essentially slows down the lipid peroxidation which essentially protects membrane permeability and reduces the rate of seed deterioration at high temperature and RH. Radiation treatment imparts metabolic stability in seeds during storage under accelerated aging conditions. (author)

  14. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  15. GRAVITATIONAL RADIATION

    Directory of Open Access Journals (Sweden)

    Metin SALTIK

    1996-03-01

    Full Text Available According to classical electromagnetic theory, an accelerated charge or system of charges radiates electromagnetic waves. In a radio transmitter antenna charges are accelerated along the antenna and release electromagnetic waves, which is radiated at the velocity of light in the surrounding medium. All of the radio transmitters work on this principle today. In this study an analogy is established between the principles by which accelerated charge systems markes radiation and the accelerated mass system, and the systems cousing gravitational radiation are investigated.

  16. MVP Chemotherapy and Hyperfractionated Radiotherapy for Stage III Unresectable Non-Small Cell Lung Cancer - Randomized for maintenance Chemotherapy vs. Observation; Preliminary Report-

    International Nuclear Information System (INIS)

    Choi, Euk Kyung; Chang, Hye Sook; Suh, Cheol Won

    1991-01-01

    To evaluate the effect of MVP chemotherapy and hyperfractionated radiotherapy in Stage III unresectable non small cell lung cancer (NSCLC), authors have conducted a prospective randomized study since January 1991. Stage IIIa or IIIb unresectable NSCLC patients were treated with hyperfractionated radiotherapy (120 cGy/fx BID) up to 6500 cGY following 3 cycles of induction MVP (Mitomycin C 6 mg/m 2 , vinblastine 6 mg/m 2 , Cisplatin 60 mg/m 2 ) and randomized for either observation or 3 cycles of maintenance MVP chemotherapy. Until August 1991, 18 patients were registered to this study. 4 cases were stage IIIa and 14 were stage IIIb. Among 18 cases 2 were lost after 2 cycles of chemotherapy, and 16 were analyzed for this preliminary report. The response rate of induction chemotherapy was 62.5%; partial response, 50% and minimal response, 12.5%. Residual tumor of the one partial responder was completely disappeared after radiotherapy. Among 6 cases who were progressed during induction chemotherapy, 4 of them were also progressed after radiotherapy. All patients were tolerated BID radiotherapy without definite increase of acute complications, compared with conventional radiotherapy group. But at the time of this report, one patient expired in two month after the completion of the radiotherapy because of treatment related complication. Although the longer follow up is needed, authors are encouraged with higher response rate and acceptable toxicity of this treatment. Authors believe that this study is worthwhile to continue

  17. Measurement and analysis of the electric field radiation in pulsed power system of linear induction accelerator

    International Nuclear Information System (INIS)

    Cheng Qifeng; Ni Jianping; Meng Cui; Cheng Cheng; Liu Yinong; Li Jin

    2009-01-01

    The close of high voltage switch in pulsed power system of linear induction accelerator often radiates strong transient electric field, which may influence ambient sensitive electric equipment, signals and performance of other instruments, etc. By performing gridded measurement around the Marx generator, the general distribution law and basic characters of electric field radiation are summarized. The current signal of the discharge circuit is also measured, which demonstrates that the current and the radiated electric field both have a resonance frequency about 150 kHz, and contain much higher frequency components. (authors)

  18. Hyperfractionated stereotactic reirradiation for recurrent head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cvek, Jakub; Knybel, Lukas; Skacelikova, Eva; Otahal, Bretislav; Molenda, Lukas; Feltl, David [University Hospital Ostrava, Department of Oncology, Ostrava (Czech Republic); Stransky, Jiri; Res, Oldrich [University Hospital Ostrava, Department of Maxilofacial Surgery, Ostrava (Czech Republic); Matousek, Petr; Zelenik, Karol [University Hospital Ostrava, Department of Otolaryngology, Ostrava (Czech Republic)

    2016-01-15

    The goal of this work was to evaluate the efficacy and toxicity of hyperfractionated stereotactic reirradiation (re-RT) as a treatment for inoperable, recurrent, or second primary head and neck squamous cell cancer (HNSCC) that is not suitable for systemic treatment. Forty patients with recurrent or second primary HNSCC were included in this study. The patients had a median gross tumor volume of 76 ml (range 14-193 ml) and a previous radiotherapy dose greater than 60 Gy. Treatment was designed to cover 95 % of the planning target volume (PTV, defined as gross tumor volume [GTV] + 3 mm to account for microscopic spreading, with no additional set-up margin) with the prescribed dose (48 Gy in 16 fractions b.i.d.). Treatment was administered twice daily with a minimum 6 h gap. Uninvolved lymph nodes were not irradiated. Treatment was completed as planned for all patients (with median duration of 11 days, range 9-14 days). Acute toxicity was evaluated using the RTOG/EORTC scale. A 37 % incidence of grade 3 mucositis was observed, with recovery time of ≤ 4 weeks for all of these patients. Acute skin toxicity was never observed to be higher than grade 2. Late toxicity was also evaluated according to the RTOG/EORTC scale. Mandible radionecrosis was seen in 4 cases (10 %); however, neither carotid blowout syndrome nor other grade 4 late toxicity occurred. One-year overall survival (OS) and local progression-free survival (L-PFS) were found to be 33 and 44 %, respectively. Performance status and GTV proved to be significant prognostic factors regarding local control and survival. Hyperfractionated stereotactic re-RT is a reasonable treatment option for patients with recurrent/second primary HNSCC who were previously exposed to high-dose irradiation and who are not candidates for systemic treatment or hypofractionation. (orig.) [German] Ziel der Studie war es, die Effektivitaet und Toxizitaet der hyperfraktionierten akzelerierten stereotaktischen Wiederbestrahlung (re

  19. Machine and radiation protection challenges of high energy/intensity accelerators: the role of Monte Carlo calculations

    Science.gov (United States)

    Cerutti, F.

    2017-09-01

    The role of Monte Carlo calculations in addressing machine protection and radiation protection challenges regarding accelerator design and operation is discussed, through an overview of different applications and validation examples especially referring to recent LHC measurements.

  20. Experimental Evidence of Radiation Reaction in the Collision of a High-Intensity Laser Pulse with a Laser-Wakefield Accelerated Electron Beam

    Science.gov (United States)

    Cole, J. M.; Behm, K. T.; Gerstmayr, E.; Blackburn, T. G.; Wood, J. C.; Baird, C. D.; Duff, M. J.; Harvey, C.; Ilderton, A.; Joglekar, A. S.; Krushelnick, K.; Kuschel, S.; Marklund, M.; McKenna, P.; Murphy, C. D.; Poder, K.; Ridgers, C. P.; Samarin, G. M.; Sarri, G.; Symes, D. R.; Thomas, A. G. R.; Warwick, J.; Zepf, M.; Najmudin, Z.; Mangles, S. P. D.

    2018-02-01

    The dynamics of energetic particles in strong electromagnetic fields can be heavily influenced by the energy loss arising from the emission of radiation during acceleration, known as radiation reaction. When interacting with a high-energy electron beam, today's lasers are sufficiently intense to explore the transition between the classical and quantum radiation reaction regimes. We present evidence of radiation reaction in the collision of an ultrarelativistic electron beam generated by laser-wakefield acceleration (ɛ >500 MeV ) with an intense laser pulse (a0>10 ). We measure an energy loss in the postcollision electron spectrum that is correlated with the detected signal of hard photons (γ rays), consistent with a quantum description of radiation reaction. The generated γ rays have the highest energies yet reported from an all-optical inverse Compton scattering scheme, with critical energy ɛcrit>30 MeV .

  1. Accelerator business in Japan expanding

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    Accelerators have become to be used increasingly in Japan in such fields as medicine, physics research and industry. This has caused stiff competition for market share by the manufacturers of accelerators. Electron beam accelerators for industrial use provide an indispensable means for adding values to products, for example, electric cables with incombustible insulators. Linear accelerators for the nondestructive inspection of nuclear components have been widely installed at equipment manufacturing plants. Active efforts have been exerted to develop small synchrotron radiation accelerators for next generation electronic industry. Cyclotrons for producing short life radioisotopes for medical diagnosis and electron beam accelerators for radiation therapy are also used routinely. The suppliers of accelerators include the companies manufacturing heavy electric machinery, heavy machinery and the engineering division of steelmakers. Accelerator physics is being formed, but universities do not yet offer the course regarding accelerators. Accelerator use in Japan and the trend of accelerator manufacturers are reported. (K.I.)

  2. Application of electron accelerator worldwide

    International Nuclear Information System (INIS)

    Machi, Sueo

    2003-01-01

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  3. Application of electron accelerator worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Sueo [Japan Atomic Industrial Forum, Inc., Tokyo (Japan)

    2003-02-01

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  4. Accelerated radiation damage test facility using a 5 MV tandem ion accelerator

    Science.gov (United States)

    Wady, P. T.; Draude, A.; Shubeita, S. M.; Smith, A. D.; Mason, N.; Pimblott, S. M.; Jimenez-Melero, E.

    2016-01-01

    We have developed a new irradiation facility that allows to perform accelerated damage tests of nuclear reactor materials at temperatures up to 400 °C using the intense proton (spectrum of potential radio-active nuclides produced during the sample irradiation. The beam line capabilities have been tested by irradiating a 20Cr-25Ni-Nb stabilised stainless steel with a 3 MeV proton beam to a dose level of 3 dpa. The irradiation temperature was 356 °C, with a maximum range in temperature values of ±6 °C within the first 24 h of continuous irradiation. The sample stage is connected to ground through an electrometer to measure accurately the charge deposited on the sample. The charge can be integrated in hardware during irradiation, and this methodology removes uncertainties due to fluctuations in beam current. The measured gamma spectrum allowed the identification of the main radioactive nuclides produced during the proton bombardment from the lifetimes and gamma emissions. This dedicated radiation damage beam line is hosted by the Dalton Cumbrian Facility of the University of Manchester.

  5. Machine and radiation protection challenges of high energy/intensity accelerators: the role of Monte Carlo calculations

    Directory of Open Access Journals (Sweden)

    Cerutti F.

    2017-01-01

    Full Text Available The role of Monte Carlo calculations in addressing machine protection and radiation protection challenges regarding accelerator design and operation is discussed, through an overview of different applications and validation examples especially referring to recent LHC measurements.

  6. Accelerated degradation by UV radiation of adhesive materials used in solar equipment

    International Nuclear Information System (INIS)

    Tilca, F.; Acosta, D; Barcena, H.; Suarez, H.; Cadena, C.; Bolzi, Claudio

    2003-01-01

    Several materials which are used as common adhesives in photovoltaic cells, were tested in order to study their stability. Accelerated degradation effects were produced using high radiation doses of UV-C and UV-b in a previously described camera at different times. The exposed and unexposed films were studied by transmittance, X-ray diffraction and infrared. The results are in agreement with complex degradation process at long exposition times, while transmittance doesn't change significantly. (author)

  7. Compact and intense parametric x-ray radiation source based on a linear accelerator with cryogenic accelerating and decelerating copper structures

    Science.gov (United States)

    Hyun, J.; Satoh, M.; Yoshida, M.; Sakai, T.; Hayakawa, Y.; Tanaka, T.; Hayakawa, K.; Sato, I.; Endo, K.

    2018-01-01

    This paper describes a proposal for a compact x-ray source based on parametric x-ray radiation (PXR). The PXR, which is produced when a single crystal is bombarded with relativistic electrons, has good monochromaticity and spatial coherence, and is expected to be well suited for imaging of low-Z materials and medical application. The proposed system employs a pair of copper accelerating structures which are operated at a cryogenic temperature of 20 K and arranged to form a resonant ring configuration. The electron beam is once accelerated up to 75 MeV in one of the structures, being decelerated down to lower than 7 MeV in the other structure after generating PXR at a single crystal, and then dumped. The expected x-ray yield is 1 09 photons /s at a center energy of 15 keV or higher.

  8. Fifteen-year results of a randomized prospective trial of hyperfractionated chest wall irradiation versus once-daily chest wall irradiation after chemotherapy and mastectomy for patients with locally advanced noninflammatory breast cancer

    International Nuclear Information System (INIS)

    Buchholz, Thomas A.; Strom, Eric A.; Oswald, Mary Jane; Perkins, George H.; Oh, Julia; Domain, Delora; Yu, Tse-Kuan; Woodward, Wendy A.; Tereffe, Welela; Singletary, S. Eva; Thomas, Eva; Buzdar, Aman U.; Hortobagyi, Gabriel N.; McNeese, Marsha D.

    2006-01-01

    Purpose: To analyze the results of a Phase III clinical trial that investigated whether a hyperfractionated radiotherapy (RT) schedule could reduce the risk of locoregional recurrence in patients with locally advanced breast cancer treated with chemotherapy and mastectomy. Methods and Materials: Between 1985 and 1989, 200 patients with clinical Stage III noninflammatory breast cancer were enrolled in a prospective study investigating neoadjuvant and adjuvant chemotherapy. Of the 179 patients treated with mastectomy after neoadjuvant chemotherapy, 108 participated in a randomized component of the trial that compared a dose-escalated, hyperfractionated (twice-daily, b.i.d.) chest wall RT schedule (72 Gy in 1.2-Gy b.i.d. fractions) with a once-daily (q.d.) schedule (60 Gy in 2-Gy q.d. fractions). In both arms of the study, the supraclavicular fossa and axillary apex were treated once daily to 50 Gy. The median follow-up period was 15 years. Results: The 15-year actuarial locoregional recurrence rate was 7% for the q.d. arm and 12% for the b.i.d. arm (p = 0.36). The rates of severe acute toxicity were similar (4% for q.d. vs. 5% for b.i.d.), but moist desquamation developed in 42% of patients in the b.i.d. arm compared with 28% of the patients in the q.d. arm (p = 0.16). The 15-year actuarial rate of severe late RT complications did not differ between the two arms (6% for q.d. vs. 11% for b.i.d., p = 0.54). Conclusion: Although the sample size of this study was small, we found no evidence that this hyperfractionation schedule of postmastectomy RT offered a clinical advantage. Therefore, we have concluded that it should not be further studied in this cohort of patients

  9. Experimental Evidence of Radiation Reaction in the Collision of a High-Intensity Laser Pulse with a Laser-Wakefield Accelerated Electron Beam

    Directory of Open Access Journals (Sweden)

    J. M. Cole

    2018-02-01

    Full Text Available The dynamics of energetic particles in strong electromagnetic fields can be heavily influenced by the energy loss arising from the emission of radiation during acceleration, known as radiation reaction. When interacting with a high-energy electron beam, today’s lasers are sufficiently intense to explore the transition between the classical and quantum radiation reaction regimes. We present evidence of radiation reaction in the collision of an ultrarelativistic electron beam generated by laser-wakefield acceleration (ϵ>500  MeV with an intense laser pulse (a_{0}>10. We measure an energy loss in the postcollision electron spectrum that is correlated with the detected signal of hard photons (γ rays, consistent with a quantum description of radiation reaction. The generated γ rays have the highest energies yet reported from an all-optical inverse Compton scattering scheme, with critical energy ϵ_{crit}>30  MeV.

  10. TIARA electrostatic accelerator facility

    International Nuclear Information System (INIS)

    Tajima, Satoshi; Takada, Isao; Mizuhashi, Kiyoshi; Uno, Sadanori; Ohkoshi, Kiyonori; Nakajima, Yoshinori; Saitoh, Yuichi; Ishii, Yasuyuki; Kamiya, Tomihiro

    1996-07-01

    In order to promote the Advanced Radiation Technology Project, Japan Atomic Energy Research Institute constructed TIARA facility composed of four ion accelerators at Takasaki Radiation Chemistry Research Establishment for the period from 1988 to 1993. A 3MV tandem accelerator and an AVF cycrotron were completed in 1991 as the first phase of the construction, and a 3MV single-ended accelerator and a 400kV ion implanter were completed in 1993 as the second phase. Three electrostatic accelerators, the tandem, the single-ended and the implanter, were installed in the Multiple-beam facility of TIARA and have been operated for various experiments with using single, dual and triple beams without any serious trouble. This report describes the constructive works, machine performances, control systems, safety systems and accessory equipments of the electrostatic accelerators. (author)

  11. CAS CERN Accelerator School: Fourth general accelerator physics course

    International Nuclear Information System (INIS)

    Turner, S.

    1991-01-01

    The fourth CERN Accelerator School (CAS) basic course on General Accelerator Physics was given at KFA, Juelich, from 17 to 28 September 1990. Its syllabus was based on the previous similar courses held at Gif-sur-Yvette in 1984, Aarhus 1986, and Salamanca 1988, and whose proceedings were published as CERN Reports 85-19, 87-10, and 89-05, respectively. However, certain topics were treated in a different way, improved or extended, while new subjects were introduced. All of these appear in the present proceedings, which include lectures or seminars on the history and applications of accelerators, phase space and emittance, chromaticity, beam-beam effects, synchrotron radiation, radiation damping, tune measurement, transition, electron cooling, the designs of superconducting magnets, ring lattices, conventional RF cavities and ring RF systems, and an introduction to cyclotrons. (orig.)

  12. Molecular ion acceleration using tandem accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Yuichi; Mizuhashi, Kiyoshi; Tajima, Satoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1996-12-01

    In TIARA compound beam radiation system, cluster beams have been produced using 3 MV tandem accelerator (9SDH-2) to supply them to various radiation on injection experiments. Till now, productions of C{sub 2-8}, Si{sub 2-4} and O{sub 2} and their accelerations up to 6 MeV have been succeeded. This study aimed at production and acceleration of B{sub 2-4} and LiF. Anion clusters were produced using the conventional ion source of cesium sputter type. The proportions of atoms, molecules and clusters elicited from the ion source were varied depending on the material`s properties and the operating conditions of ion source such as sample temperature, sputter voltage and the shape of sample. The anion clusters were accelerated toward the high voltage terminal in the center of tandem accelerator, leading to cations through losing their electrons by the collision to N{sub 2} gas in a charge conversion cell at the terminal. Positively charged cluster ions could be obtained by modulating the pressure of N{sub 2} gas. Thus, B{sub 2} (64 nA), B{sub 3} (4.4 nA) and B{sub 4} (2.7 nA) have been produced and their maximum survival probabilities were higher than those of carbon or silicon clusters. In addition, the relationship between beam current and gas pressure was investigated for Bn (n = 2-4) and LiF. (M.N.)

  13. Radiation recall secondary to adjuvant docetaxel after balloon-catheter based accelerated partial breast irradiation

    International Nuclear Information System (INIS)

    Wong, Nathan W.; Wong, William W.; Karlin, Nina J.; Gray, Richard J.

    2010-01-01

    For early stage breast cancer, wide local excision and post-operative whole breast irradiation is a standard treatment. If adjuvant chemotherapy is recommended, radiation is usually given after completion of chemotherapy. In recent years, accelerated partial breast irradiation (APBI) with balloon-cathetered based brachytherapy has become an option for selected patients. For these patients, adjuvant chemotherapy would have to be administered after radiation. The sequence of treatment with radiation followed by chemotherapy results in increased risk of radiation recall reaction (RRD) in these patients. Docetaxel is becoming a more commonly used drug as adjuvant treatment for breast cancer. Here we report a case of docetaxel induced RRD after APBI with balloon-cathetered based brachytherapy. Such reaction would have an adverse impact on the cosmetic outcome and quality of life of the patient. For patients who develop an intense skin reaction after the administration of docetaxel following APBI, RRD should be considered in the differential diagnosis.

  14. Interactive visual intervention planning in particle accelerator environments with ionizing radiation

    International Nuclear Information System (INIS)

    Fabry, Thomas

    2014-01-01

    radiation. Several industrial and scientific procedures give rise to facilities with ionizing radiation. Most technical and scientific facilities also need maintenance operations. In the spirit of ALARA, these interventions need to be optimized in terms of the exposure of the maintenance workers to ionizing radiation. This optimization cannot be automated since the feasibility of the intervention tasks requires human assessment. The intervention planning could however be facilitated by technical-scientific means, e.g. software tools. In the context sketched above, this thesis provides technical-scientific considerations and the development of technical-scientific methodologies and software tools for the implementation of radiation protection.In particular, this thesis addresses the need for an interactive visual intervention planning tool in the context of high energy particle accelerator facilities. (author)

  15. State registration and inspection programs for particle accelerators

    International Nuclear Information System (INIS)

    Bailey, E.D.

    1976-01-01

    The Suggested State Regulations for Control of Radiation(SSRCR) are recommended by the Council of State Governments and the National Conference of Radiation Control Program Directors as the model regulations which states should adopt in order to have adequate regulation and uniformity from state to state. These regulations are used as a basis for reviewing the current status of accelerator regulation in each state. The SSRCR does contain a separate part for registration (Part B--Registration of Radiation Machine Facilities and Services) and a separate part (Part I--Radiation Safety Requirements for Particle Accelerators) with specific requirements for the possession and use of accelerators. In addition, medical accelerators have additional requirements in Part F--X-Rays in The Heating Acts. These regulations specify requirements related to limitations of use, shielding and safety design requirements, control and interlock systems, warning devices, operating procedures, radiation monitoring, and calibration of medical accelerators

  16. The constructive solution of the Greifswald linear accelerator 'Neptun 10 p' project from the point of view of radiation protection

    International Nuclear Information System (INIS)

    Schmidt, W.; Waag, V.; Nadrowitz, R.; Wendorff, W.

    1981-01-01

    In 1981 the linear accelerator 'Neptun 10 p' will be mounted at the Radiological Clinic of the University of Greifswald. Its place will be an irradiation room which is equipped for a radiation of 1.33 MeV. The strengthening of walls and celling, which is necessary for 9 MeV bremsstrahlung and 10 MeV electron radiation, can only be realized by a self-supporting lead-steel construction for reasons of the distance to the neighbouring house and of the connected conditions of foundation as well as of the load capacity of the existing construction of the roof. As in the eighties similar problems are to be expected in other radiological hospitals of the GDR the constructive solution of the Greifswald linear accelerator project and connected problems of the radiation protection are represented. (author)

  17. Radiation effects in materials for accelerator-driven neutron technologies. Revision

    International Nuclear Information System (INIS)

    Wechsler, M.S.; Lin, C.; Sommer, W.F.

    1997-01-01

    Accelerator-driven neutron technologies use spallation neutron sources (SNS's) in which high-energy protons bombard a heavy-element target and spallation neutrons are produced. The materials exposed to the most damaging radiation environments in an SNS are those in the path of the incident proton beam. This includes target and window materials. These materials will experience damage from the incident protons and the spallation neutrons. In addition, some materials will be damaged by the spallation neutrons alone. The principal materials of interest for SNS's are discussed elsewhere. The target should consist of one or more heavy elements, so as to increase the number of neutrons produced per incident proton. A liquid metal target (e.g., Pb, Bi, Pb-Bi, Pb-Mg, and Hg) has the advantage of eliminating the effects of radiation damage on the target material itself, but concerns over corrosion problems and the influence of transmutants remain. The major solid targets in operating SNS's and under consideration for the 1-5 MW SNS's are W, U, and Pb. Tungsten is the target material at LANSCE, and is the projected target material for an upgraded LANSCE target that is presently being designed. It is also the projected target material for the tritium producing SNS under design at LANL. In this paper, the authors present the results of spallation radiation damage calculations (displacement and He production) for tungsten

  18. INVESTIGATION OF SECONDARY MIXED RADIATION FIELD AROUND A MEDICAL LINEAR ACCELERATOR.

    Science.gov (United States)

    Tulik, Piotr; Tulik, Monika; Maciak, Maciej; Golnik, Natalia; Kabat, Damian; Byrski, Tomasz; Lesiak, Jan

    2017-09-29

    The aim of this study is to investigate secondary mixed radiation field around linac, as the first part of an overall assessment of out-of-field contribution of neutron dose for new advanced radiation dose delivery techniques. All measurements were performed around Varian Clinic 2300 C/D accelerator at Maria Sklodowska-Curie Memorial, Cancer Center and Institute of Oncology, Krakow Branch. Recombination chambers REM-2 and GW2 were used for recombination index of radiation quality Q4 determination (as an estimate of quality factor Q), measurement of total tissue dose Dt and calculation of gamma and neutron components to Dt. Estimation of Dt and Q4 allowed for the ambient dose equivalent H*(10) per monitor unit (MU) calculations. Measurements around linac were performed on the height of the middle of the linac's head (three positions) and on the height of the linac's isocentre (five positions). Estimation of secondary radiation level was carried out for seven different configurations of upper and lower jaws position and multileaf collimator set open or closed in each position. Study includes the use of two photon beam modes: 6 and 18 MV. Spatial distribution of ambient dose equivalent H*(10) per MU on the height of the linac's head and on the standard couch height for patients during the routine treatment, as well as relative contribution of gamma and neutron secondary radiation inside treatment room were evaluated. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. The influence of potential exposure to radiation protection system of accelerator installation TESLA

    International Nuclear Information System (INIS)

    Orlic, M.; Cuknic, O.

    2000-01-01

    Potential exposure of individuals at big nuclear machines like Accelerator Installation Tesla (AIT) generates direct requirements to reliability of radiation protection system. Starting from technical characteristics of AlT and international recommendation concerning potential exposure and the probability of death has been calculated. The reference risk has been specified. Comparing then we calculated the probability of the failure of the protective system. The reliability of the system has to be better (author)

  20. Is it time to rethink the role of hyperfractionated radiotherapy in the management of children with newly-diagnosed brainstem glioma?: Results of a Pediatric Oncology Group Phase III trial comparing conventional VS. hyperfractionated radiotherapy

    International Nuclear Information System (INIS)

    Mandell, L.; Kadota, R.; Douglass, E.C.; Fontanesi, J.; Freeman, C.; Cohen, M.; Kovnar, E.; Burger, P.; Sanford, R.A.; Kepner, J.; Friedman, H.; Kun, L.

    1997-01-01

    Purposes/Objective: In June 1992, POG began accrual to a Phase III study, POG 9239, designed to compare the time to disease progression, overall survival, and toxicities observed in children with newly diagnosed brainstem glioma treated with 100 mg/m 2 of infusional Cisplatin and randomized to either conventional vs. hyperfractionated radiotherapy. The trial was closed in March 1996, having achieved its accrual goal. Materials and Methods: Patients (pts) eligible for study were those between 3 and 21 years of age with previously untreated tumors arising in the pons. Histologic confirmation of diagnosis was not mandatory, provided that the clinical and MRI scan findings were typical for diffusely infiltrating pontine glioma. Treatment (Rx) consisted of a six-week course of local field radiotherapy with either once a day treatment (Rx 1) of 180 cGy per fraction to a total dose of 5400 cGy or a twice a day regimen (Rx 2) of 117 cGy per fraction to a total dose of 7020 cGy (the second of the three hyperfractionated dose escalation levels of POG 8495). Because of previously reported poor results with conventional radiotherapy alone, Cisplatin was included as a potential radiosensitizer in an attempt to improve progression-free and ultimate survival rates. Based on results of the Phase I Cisplatin dose escalation trial, POG 9139, 100 mg/m 2 was chosen for this trial and was delivered by continuous infusion over a 120-hour period, beginning on the first day of radiotherapy and repeated during Weeks 3 and 5. Of the 132 pts accrued to the study, 94 are eligible for review based upon time since entry, 47 in each Rx arm. In Rx 1, there were 23 males and 24 females, ranging in age from 40 to 161 mo (median, 77 mo); in Rx 2, there were 20 males and 27 females, ranging in age from 41 to 212 mo (median, 77 mo). As of 4/18/96, the study coordinator had not yet verified eligibility and assessed the evaluability of the remaining pts. Results: All results are from time of diagnosis

  1. Lung damage following bone marrow transplantation after hyperfractionated total body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Latini, Paolo; Aristei, Cynthia; Checcaglini, Franco; Maranzano, Ernesto; Panizza, B.M.; Perrucci, Elisabetta (University and Hospital, Policlinico, Perugia (Italy). Radiation Oncology Service); Aversa, Franco; Martelli, M.F. (University and Hospital, Policlinico, Perugia (Italy). Department of Haematology); Raymondi, Carlo (University and Hospital, Policlinico, Perugia (Italy). Radiation Physics Service)

    1991-10-01

    From July 1985 to December 1989, 72 evaluable patients aged 6-51 (median age 27) suffering from hematological malignancies received allo-geneic bone marrow transplant (BMT) depleted of T-lymphocytes to reduce risks of graft-versus-host-disease (GvHD); 57 were matched and 15 mis-matched. Three different conditioning regiments were used in an effort to enhance cytoreduction without increase extramedullary toxicity. Mis-matched patients were treated with more immunosuppressive regimens. Total body irradiation (TBI) was given in 3 doses/day, 5 h apart over 4 days for a total of 12 fractions. The dose to the lungs was 14.4, 15.6 and 9 Gy according to the conditioning regimen. The incidence of inter-stitial pneumonia (IP) was 12.3 percent in matched and 46.7 in mis-matched patients. The results seem to indicate that lung toxicity is correlated with the intensity of the conditioning regimen, the stage of disease and, in mismatched patients, with the degree of human leucocyte antigen (HLA) disparity and the poor post-BMT reconstitution, rather than the radiotherapy dose delivered to the lungs. On the contrary, the hyperfractionated scheme adopted, the absence of GvHD and, perhaps, the post-TBI administration of cyclophosphamide all seem to have contributed to the low incidence of IP in the matched patients. (author). 30 refs.; 5 figs.; 1 tab.

  2. Lung damage following bone marrow transplantation after hyperfractionated total body irradiation

    International Nuclear Information System (INIS)

    Latini, Paolo; Aristei, Cynthia; Checcaglini, Franco; Maranzano, Ernesto; Panizza, B.M.; Perrucci, Elisabetta; Aversa, Franco; Martelli, M.F.; Raymondi, Carlo

    1991-01-01

    From July 1985 to December 1989, 72 evaluable patients aged 6-51 (median age 27) suffering from hematological malignancies received allo-geneic bone marrow transplant (BMT) depleted of T-lymphocytes to reduce risks of graft-versus-host-disease (GvHD); 57 were matched and 15 mis-matched. Three different conditioning regiments were used in an effort to enhance cytoreduction without increase extramedullary toxicity. Mis-matched patients were treated with more immunosuppressive regimens. Total body irradiation (TBI) was given in 3 doses/day, 5 h apart over 4 days for a total of 12 fractions. The dose to the lungs was 14.4, 15.6 and 9 Gy according to the conditioning regimen. The incidence of inter-stitial pneumonia (IP) was 12.3 percent in matched and 46.7 in mis-matched patients. The results seem to indicate that lung toxicity is correlated with the intensity of the conditioning regimen, the stage of disease and, in mismatched patients, with the degree of human leucocyte antigen (HLA) disparity and the poor post-BMT reconstitution, rather than the radiotherapy dose delivered to the lungs. On the contrary, the hyperfractionated scheme adopted, the absence of GvHD and, perhaps, the post-TBI administration of cyclophosphamide all seem to have contributed to the low incidence of IP in the matched patients. (author). 30 refs.; 5 figs.; 1 tab

  3. Soft X-ray radiation power characteristics of tungsten wire arrays on Yang accelerator

    International Nuclear Information System (INIS)

    Zhang Siqun; Ouyang Kai; Huang Xianbin; Dan Jiakun; Zhou Rongguo; Yang Liang

    2013-01-01

    A series of experiments were carried out to research the X-ray radiation characteristics of tungsten wire arrays on Yang accelerator. In those experiments, we charged the Marx generator of 60 kV, and the load current of 0.85-1.00 MA, the rise time of 75-90 ns (10%-90%). A soft X-ray scintillator powermeter which responded flatly to 50-1800 eV X-rays was used to measure the power of soft X-ray emitted from implosion plasma. In this paper, we present the measuring results of time-resolved soft X-ray radiation power, and discuss the radiation characteristics of implosion plasma by analyzing the correlations of soft X-ray radiant power and the diameter, length, wire number of the tungsten wire arrays. The optimizing wire array configuration parameters on Yang are as follows: 8 mm array diameter, 15 mm wire length, and 24 wire number. We also present the radiant power difference in radial and axial directions of the wire arrays. (authors)

  4. Non-LTE radiative transfer with lambda-acceleration - Convergence properties using exact full and diagonal lambda-operators

    Science.gov (United States)

    Macfarlane, J. J.

    1992-01-01

    We investigate the convergence properties of Lambda-acceleration methods for non-LTE radiative transfer problems in planar and spherical geometry. Matrix elements of the 'exact' A-operator are used to accelerate convergence to a solution in which both the radiative transfer and atomic rate equations are simultaneously satisfied. Convergence properties of two-level and multilevel atomic systems are investigated for methods using: (1) the complete Lambda-operator, and (2) the diagonal of the Lambda-operator. We find that the convergence properties for the method utilizing the complete Lambda-operator are significantly better than those of the diagonal Lambda-operator method, often reducing the number of iterations needed for convergence by a factor of between two and seven. However, the overall computational time required for large scale calculations - that is, those with many atomic levels and spatial zones - is typically a factor of a few larger for the complete Lambda-operator method, suggesting that the approach should be best applied to problems in which convergence is especially difficult.

  5. Aggressive simultaneous radiochemotherapy with cisplatin and paclitaxel in combination with accelerated hyperfractionated radiotherapy in locally advanced head and neck tumors. Results of a phase I-II trial

    Energy Technology Data Exchange (ETDEWEB)

    Kuhnt, T.; Pigorsch, S.; Pelz, T.; Haensgen, G.; Dunst, J. [Dept. of Radiotherapy, Martin Luther Univ., Halle (Germany); Becker, A. [Dept. of Radiotherapy, Martin Luther Univ., Halle (Germany); Dept. of Radiotherapy, Municipial Hospital, Dessau (Germany); Bloching, M.; Passmann, M. [Dept. of Head and Neck Surgery, Martin Luther Univ., Halle (Germany); Lotterer, E. [Dept. of Internal Medicine I, Martin Luther Univ., Halle (Germany)

    2003-10-01

    We have tested a very aggressive combination protocol with cisplatin and escalated paclitaxel in combination with accelerated hyperfractionated radiotherapy to assess the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), overall toxicity, and response rate. Patients and Methods: The trial recruited 24 patients (21 males, three females, mean age 57 years) treated at our department from 1998 through 2001. Irradiation was administered in daily doses of 2 Gy up to 30 Gy followed by 1.4 Gy twice daily up to 70.6 Gy to the primary tumor and involved nodes and 51 Gy to the clinically negative regional nodes. The chemotherapy schedule included cisplatin in a fixed dose of 20 mg/m{sup 2} on days 1-5 and 29-33 and paclitaxel at increasing dose levels of 20, 25, 30 mg/m{sup 2} twice weekly over the whole treatment time. Patients were recruited in cohorts of three to six, and the MTD was reached if two out of six patients in one cohort developed DLT. DLT was defined as any grade 4 toxicity or any grade 3 toxicity requiring treatment interruption or unplanned hospitalization or any grade 3 neurotoxicity. We recruited mainly patients with large tumors for this protocol; all patients were stage IV, and the mean tumor volume (primary + metastases) amounted to 72 {+-} 61 cm{sup 3}. The mean follow-up was 30 months (range 4-39 months). Results: One early death (peritonitis and sepsis a t day 10) occurred, and 23 patients were evaluable for acute toxicity and response. The MTD of paclitaxel was reached at the third dose level (30 mg/m{sup 2} paclitaxel twice weekly). The DLT was severe mucositis grade 3 (n = 1) and skin erythema grade 4 (n = 2). After determining the MTD, another 14 patients were treated at the recommended dose level of paclitaxel with 25 mg/m{sup 2} twice weekly. In summary, 13/23 patients (57%) developed grade 3 and 10/23 (43%) grade 2 mucositis. Two patients (9%) had grade 4, five (22%) grade 3, and 16 (69%) grade 2 dermatitis. One patient died at day 30

  6. Aggressive simultaneous radiochemotherapy with cisplatin and paclitaxel in combination with accelerated hyperfractionated radiotherapy in locally advanced head and neck tumors. Results of a phase I-II trial

    International Nuclear Information System (INIS)

    Kuhnt, T.; Pigorsch, S.; Pelz, T.; Haensgen, G.; Dunst, J.; Becker, A.; Bloching, M.; Passmann, M.; Lotterer, E.

    2003-01-01

    We have tested a very aggressive combination protocol with cisplatin and escalated paclitaxel in combination with accelerated hyperfractionated radiotherapy to assess the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), overall toxicity, and response rate. Patients and Methods: The trial recruited 24 patients (21 males, three females, mean age 57 years) treated at our department from 1998 through 2001. Irradiation was administered in daily doses of 2 Gy up to 30 Gy followed by 1.4 Gy twice daily up to 70.6 Gy to the primary tumor and involved nodes and 51 Gy to the clinically negative regional nodes. The chemotherapy schedule included cisplatin in a fixed dose of 20 mg/m 2 on days 1-5 and 29-33 and paclitaxel at increasing dose levels of 20, 25, 30 mg/m 2 twice weekly over the whole treatment time. Patients were recruited in cohorts of three to six, and the MTD was reached if two out of six patients in one cohort developed DLT. DLT was defined as any grade 4 toxicity or any grade 3 toxicity requiring treatment interruption or unplanned hospitalization or any grade 3 neurotoxicity. We recruited mainly patients with large tumors for this protocol; all patients were stage IV, and the mean tumor volume (primary + metastases) amounted to 72 ± 61 cm 3 . The mean follow-up was 30 months (range 4-39 months). Results: One early death (peritonitis and sepsis a t day 10) occurred, and 23 patients were evaluable for acute toxicity and response. The MTD of paclitaxel was reached at the third dose level (30 mg/m 2 paclitaxel twice weekly). The DLT was severe mucositis grade 3 (n = 1) and skin erythema grade 4 (n = 2). After determining the MTD, another 14 patients were treated at the recommended dose level of paclitaxel with 25 mg/m 2 twice weekly. In summary, 13/23 patients (57%) developed grade 3 and 10/23 (43%) grade 2 mucositis. Two patients (9%) had grade 4, five (22%) grade 3, and 16 (69%) grade 2 dermatitis. One patient died at day 30 of neutropenic infection

  7. Radiation environment in the tunnel of a high-energy proton accelerator at energies near 1 TeV

    International Nuclear Information System (INIS)

    McCaslin, J.B.; Sun, R.K.S.; Swanson, W.P.

    1987-12-01

    Neutron energy spectra, fluence distributions and rates in the FNAL Tevatron tunnel are summarized. This work has application to radiation damage to electronics and research equipment at high energy accelerators, as well as to radiological protection. 7 refs., 4 figs

  8. Accelerated thermal and radiation-oxidation combined degradation of electric cable insulation materials

    International Nuclear Information System (INIS)

    Yagi, Toshiaki; Seguchi, Tadao; Yoshida, Kenzo

    1986-03-01

    For the development of accelerated testing methodology to estimate the life time of electric cable, which is installed in radiation field such as a nuclear reactor containment vessel, radiation and thermal combined degradation of cable insulation and jacketing materials was studied. The materials were two types of formulated polyethylene, ethylene-propylene rubber, Hypalon, and Neoprene. With Co-60 γ-rays the materials were irradiated up to 0.5 MGy under vacuum and in oxygen under pressure, then exposed to thermal aging at elevated temperature in oxygen. The degradation was investigated by the tensile test, gelfraction, and swelling measurements. The thermal degradation rate for each sample increases with increase of oxygen concentration, i.e. oxygen pressure, during the aging, and tends to saturate above 0.2 MPa of oxygen pressure. Then, the effects of irradiation and the temperature on the thermal degradation rate were investigated at the oxygen pressure of 0.2 MPa in the temperature range from 110 deg C to 150 deg C. For all of samples irradiated in oxygen, the following thermal degradation rate was accelerated by several times comparing with unirradiated samples, while the rate of thermal degradation for the sample except Neoprene irradiated under vacuum was nearly equal to that of unirradiated one. By the analysis of thermal degradation rate against temperature using Arrhenius equation, it was found that the activation energy tends to decrease for the samples irradiated in oxidation condition. (author)

  9. Induced radioactivity of materials by stray radiation fields at an electron accelerator

    CERN Document Server

    Rokni, S H; Gwise, T; Liu, J C; Roesler, S

    2002-01-01

    Samples of soil, water, aluminum, copper and iron were irradiated in the stray radiation field generated by the interaction of a 28.5 GeV electron beam in a copper-dump in the Beam Dump East facility at the Stanford Linear Accelerator Center. The specific activity induced in the samples was measured by gamma spectroscopy and other techniques. In addition, the isotope production in the samples was calculated with detailed Monte Carlo simulations using the FLUKA code. The calculated activities are compared to the experimental values and differences are discussed.

  10. Application accelerator system having bunch control

    Science.gov (United States)

    Wang, Dunxiong; Krafft, Geoffrey Arthur

    1999-01-01

    An application accelerator system for monitoring the gain of a free electron laser. Coherent Synchrotron Radiation (CSR) detection techniques are used with a bunch length monitor for ultra short, picosec to several tens of femtosec, electron bunches. The monitor employs an application accelerator, a coherent radiation production device, an optical or beam chopping device, an infrared radiation collection device, a narrow-banding filter, an infrared detection device, and a control.

  11. Radiation resistance of polymer materials. Degradation evaluation by accelerated testing for application condition

    International Nuclear Information System (INIS)

    Seguchi, Tadao; Tamura, Kiyotoshi; Sorimachi, Masami

    2010-02-01

    This paper presents re-evaluated radiation resistance property data of polymer materials, which had been tested in past times in TAKASAKI Quantum Beam Science Directorate, for the future study of ageing evaluation of low voltage electric cable insulation materials used in light-water nuclear reactors. The radiation resistance of 25 types of plastics and rubbers materials applied in practical environments was evaluated by the accelerated testing of gamma-ray irradiation under oxygen pressure, and was compared with the radiation resistance determined from the traditional testing by irradiation with a high dose rate in air. The polymer materials were formulated to be similar or equivalent to practical materials, and the most of formulation (chemical compounds and quantities) were described. For all materials, the tensile properties (elongation at break, ultimate strength, 100% or 200% modulus), electric resistivity, gel-fraction, and density were measured after irradiation in oxidation conditions and irradiation in air with a high dose rate (non-oxidation conditions). The data of relations between each properties and total dose at various conditions were compiled, and the relations among the changes of mechanical properties, electrical properties, and radiation induced chemical reactions were discussed. (author)

  12. Technology and applications of electron accelerator

    International Nuclear Information System (INIS)

    Natsir, M.

    1998-01-01

    Technology of electron accelerator have been developed so fast in advanced countries. It was applied in the research and development (R and D) and comercially in various industries. The industries applying electron accelerator includes polymers industry, sterilization of medical tools, material surface modification, and environmental management. The radiation process using electron beam is an ionization radiation process. Two facilities of electron accelerator have been established in pilot scale at the Centre for the Application of Isotope and Radiation CAIR-BATAN, Jakarta, for the RandD of radiation process technology and in demonstrating the electron accelerator application in industry in Indonesia. The first has low energy specification of 300 keV, 50 mA, EPS-300 type and the second has medium energy specification of 2 MeV, 10 mA dynamitron model GJ-2 type. Both the electron accelerators have an electron penetration depth capability of 0.6 and 12 mm, respectively, for the double side irradiation in the materials with density of 1 g/cm 3 . They also highly capacity production and electron beam cross-section of 120 cm length and 10 cm width. The beam will go through the atmosphere for irradiation samples or industrial products. The radiation dose can be selected precisely by adjusting the electron beam current and conveyor speed. Both of these facilities were applied in many aspects RandD, for examples dosimetry, wood surface coating, cross-linking of polymer, heatshrincable tube, polymer grafting, plastic degradation, food preservation, sterilization and so on. Engineering factors of radiation design process and general observation of electron accelerator application in RandD for various industries in Indonesia are briefly discussed

  13. Bright betatronlike x rays from radiation pressure acceleration of a mass-limited foil target.

    Science.gov (United States)

    Yu, Tong-Pu; Pukhov, Alexander; Sheng, Zheng-Ming; Liu, Feng; Shvets, Gennady

    2013-01-25

    By using multidimensional particle-in-cell simulations, we study the electromagnetic emission from radiation pressure acceleration of ultrathin mass-limited foils. When a circularly polarized laser pulse irradiates the foil, the laser radiation pressure pushes the foil forward as a whole. The outer wings of the pulse continue to propagate and act as a natural undulator. Electrons move together with ions longitudinally but oscillate around the latter transversely, forming a self-organized helical electron bunch. When the electron oscillation frequency coincides with the laser frequency as witnessed by the electron, betatronlike resonance occurs. The emitted x rays by the resonant electrons have high brightness, short durations, and broad band ranges which may have diverse applications.

  14. An Evaluation on Radiation Shielding and Activation Properties of ISOL-bunker Structural Materials for Radiation Safety in RAON Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Do Hyun; Kim, Song Hyun; Woo, Myeong Hyeon; Lee, Jae Yong; Kim, Jong Woo; Shin, Chang Ho [Hanyang University, Seoul (Korea, Republic of); Nam, Shin Woo [Institute for Basic Science, Daejeon (Korea, Republic of)

    2015-10-15

    RAON heavy ion accelerator has been designed by the Institute for Basic Science (IBS). ISOL is one of RAON facilities to generate and separate rare isotopes. For generating rare isotopes, high intensity proton beam, which has 70 MeV energy, is induced into UCx target. From this reaction, lots of neutrons are concomitantly generated. To meet our design goal, it was required that the structural material of ISOL-bunker should be carefully selected. In this study, to select the structural material which has lower activation property with higher performance for radiation shielding, following aspects were evaluated: (i) residual dose, (ii) radioactive wastes, and (iii) shielding performance in ISOL-bunker. In this study, to effectively design the radiation shielding of the RAON ISOL-bunker, two methods were proposed. No.1 strategy is a method to replace the normal concrete to specific concretes. No.2 strategy is to design dual-layer radiation shields that a specific shielding material is located inner side of the normal concrete. Using the strategies, performance evaluations were evaluated for three aspects, which are residual dose, radioactive waste, and prompt radiation. The results show that the residual radiation can be effectively reduced using B{sub 4}C, borated polyethylene and polyethylene with No.2 strategy. Also, the colemanite concrete and B{sub 4}C shielding give a good ability to reduce the radioactive wastes.

  15. Study of bremsstrahlung dose fields in radiation shield and labyrinth devices of plants with LUEH-8/5B accelerator

    International Nuclear Information System (INIS)

    Vikulin, A.A.; Vanyushkin, B.M.; Garnyk, D.V.; Kon'kov, N.G.; Terent'ev, B.M.

    1980-01-01

    Measurement results of exposure dose rate (EDR) of radiation in fields of bremsstrahlung of radiation plants with LUEh-8/5B linear accelerator of electrons by means of DRG2-03 dose meter, intended for operative measuring EDR in high intense fields of γ-radiation of powerful radioisotopic plants, are presented. Dose meter design is described. Measurements of bremsstrahlung EDR have been carried out in the chamber of plant irradiation for radiation sterilizing medical items, as well as in the chamber of VNIIRT experimental plant. RUP-1 device has been used for measuring radiation EDR in a labyrinth behind 1.8 m thick shoulder by concrete [ru

  16. Frontier applications of electrostatic accelerators

    Science.gov (United States)

    Liu, Ke-Xin; Wang, Yu-Gang; Fan, Tie-Shuan; Zhang, Guo-Hui; Chen, Jia-Er

    2013-10-01

    Electrostatic accelerator is a powerful tool in many research fields, such as nuclear physics, radiation biology, material science, archaeology and earth sciences. Two electrostatic accelerators, one is the single stage Van de Graaff with terminal voltage of 4.5 MV and another one is the EN tandem with terminal voltage of 6 MV, were installed in 1980s and had been put into operation since the early 1990s at the Institute of Heavy Ion Physics. Many applications have been carried out since then. These two accelerators are described and summaries of the most important applications on neutron physics and technology, radiation biology and material science, as well as accelerator mass spectrometry (AMS) are presented.

  17. Big Data and Comparative Effectiveness Research in Radiation Oncology: Synergy and Accelerated Discovery

    Science.gov (United States)

    Trifiletti, Daniel M.; Showalter, Timothy N.

    2015-01-01

    Several advances in large data set collection and processing have the potential to provide a wave of new insights and improvements in the use of radiation therapy for cancer treatment. The era of electronic health records, genomics, and improving information technology resources creates the opportunity to leverage these developments to create a learning healthcare system that can rapidly deliver informative clinical evidence. By merging concepts from comparative effectiveness research with the tools and analytic approaches of “big data,” it is hoped that this union will accelerate discovery, improve evidence for decision making, and increase the availability of highly relevant, personalized information. This combination offers the potential to provide data and analysis that can be leveraged for ultra-personalized medicine and high-quality, cutting-edge radiation therapy. PMID:26697409

  18. Radiation protection activities around the CERN accelerators

    International Nuclear Information System (INIS)

    Silari, M.

    1997-01-01

    The staff of the Survey Section of Radiation Protection (RP) working around the CERN accelerators were as usual very busy. The LEP2 programme is now fully on its way, with the installation of additional superconducting RF cavities carried out during both the winter and summer shutdowns. The LEP energy per beam was thus increased to 80.5 GeV in summer and to 86 GeV in autumn. ACOL and LEAR ended their operational life on 19 December producing, for the last time, antiprotons for the experiments in the South Hall; all experiments will be dismantled in 1997. This programme will be partly replaced by the future Antiproton Decelerator, which was approved by the Research Board in November. Several experiments also came to their end in the North and West Experimental Areas of the SPS. NA44 (in EHN1) and NA47 (in EHN2) ended this year. All experiments installed in beam lines HI, H3, XI and X3 in the West Area also terminated, as these beam lines will be dismantled in the course of 1997 to make room for test facilities for the LHC. Several modifications in the West and North Experimental Areas have already been undertaken at the end of the year and will be continued in 1997. Some equipment installed in the West Area will be moved to the North Area. In addition to routine work, several measurements of synchrotron radiation were made in LEP for the two new energy levels reached in 1996. A number of dedicated measurements were also undertaken in EHN1 (North Area) at the end of the year, during the lead-ion run which closed the physics period. A detailed assessment of releases of radioactivity from the ISOLDE facility was also made

  19. Application accelerator system having bunch control

    International Nuclear Information System (INIS)

    Wang, D.; Krafft, G.A.

    1999-01-01

    An application accelerator system for monitoring the gain of a free electron laser is disclosed. Coherent Synchrotron Radiation (CSR) detection techniques are used with a bunch length monitor for ultra short, picosec to several tens of femtosec, electron bunches. The monitor employs an application accelerator, a coherent radiation production device, an optical or beam chopping device, an infrared radiation collection device, a narrow-banding filter, an infrared detection device, and a control. 1 fig

  20. Proceedings of the FNCA 2002 workshop on application of electron accelerator. Radiation system for liquid samples

    International Nuclear Information System (INIS)

    Yoshii, Fumio; Kume, Tamikazu

    2003-10-01

    'Forum for Nuclear Cooperation in Asia (FNCA) Workshop on Application of Electron Accelerator' was sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and hosted by Japan Atomic Energy Research Institute (JAERI) and Japan Atomic Industry Forum (JAIF). It was held at the Takasaki Radiation Chemistry Research Establishment (TRCRE), JAERI, Takasaki, Japan from 16 to 20 December 2002. The attendants at the workshop were consisted of 13 experts on application of electron accelerator from each of the participating countries, i.e., China, Indonesia, Korea, Malaysia, the Philippines, Thailand and Vietnam, and 40 participants from Japan. A total of 18 papers including invited papers on liquid waste treatment by electron beam, reviews of the radiation systems, and designing and cost analysis of EB irradiation system were presented. The major areas of interest of FNCA countries for cooperation were identified for application of low energy electron accelerator as liquid, thin film and granules. The gas and wastewater treatments were added to the above major areas. Based on the proposal from the participating countries, discussions were carried out to re-formulate the work plan of the project for three years until FY 2004. All manuscripts submitted by every speaker were included in the proceedings. The 17 of the presented papers are indexed individually. (J.P.N.)

  1. The outflows accelerated by the magnetic fields and radiation force of accretion disks

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Xinwu, E-mail: cxw@shao.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai, 200030 (China)

    2014-03-01

    The inner region of a luminous accretion disk is radiation-pressure-dominated. We estimate the surface temperature of a radiation-pressure-dominated accretion disk, Θ=c{sub s}{sup 2}/r{sup 2}Ω{sub K}{sup 2}≪(H/r){sup 2}, which is significantly lower than that of a gas-pressure-dominated disk, Θ ∼ (H/r){sup 2}. This means that the outflow can be launched magnetically from the photosphere of the radiation-pressure-dominated disk only if the effective potential barrier along the magnetic field line is extremely shallow or no potential barrier is present. For the latter case, the slow sonic point in the outflow will probably be in the disk, which leads to a slow circular dense flow above the disk. This implies that hot gas (probably in the corona) is necessary for launching an outflow from the radiation-pressure-dominated disk, which provides a natural explanation for the observational evidence that the relativistic jets are related to hot plasma in some X-ray binaries and active galactic nuclei. We investigate the outflows accelerated from the hot corona above the disk by the magnetic field and radiation force of the accretion disk. We find that with the help of the radiation force, the mass loss rate in the outflow is high, which leads to a slow outflow. This may be why the jets in radio-loud narrow-line Seyfert galaxies are in general mildly relativistic compared with those in blazars.

  2. Error-Rate Estimation Based on Multi-Signal Flow Graph Model and Accelerated Radiation Tests.

    Directory of Open Access Journals (Sweden)

    Wei He

    Full Text Available A method of evaluating the single-event effect soft-error vulnerability of space instruments before launched has been an active research topic in recent years. In this paper, a multi-signal flow graph model is introduced to analyze the fault diagnosis and meantime to failure (MTTF for space instruments. A model for the system functional error rate (SFER is proposed. In addition, an experimental method and accelerated radiation testing system for a signal processing platform based on the field programmable gate array (FPGA is presented. Based on experimental results of different ions (O, Si, Cl, Ti under the HI-13 Tandem Accelerator, the SFER of the signal processing platform is approximately 10-3(error/particle/cm2, while the MTTF is approximately 110.7 h.

  3. CAS CERN accelerator school: 5. general accelerator physics course. Vol. 2. Proceedings

    International Nuclear Information System (INIS)

    Turner, S.

    1994-01-01

    The fifth CERN Accelerator School (CAS) basic course on General Accelerator Physics was given at the University of Jyvaeskylae, Finland, from 7 to 18 September 1992. Its syllabus was based on the previous similar courses held at Gif-sur-Yvette in 1984, Aarhus 1986, Salamanca 1988 and Juelich 1990, and whose proceedings were published as CERN Reports 85-19, 87-10, 89-05 and 91-04, respectively. However, certain topics were treated in a different way, improved or extended, while new subjects were introduced. As far as the proceedings of this school are concerned the opportunity was taken not only to include the lectures presented but also to select and revise the most appropriate chapters from the previous similar schools. In this way the present volumes constitute a rather complete introduction to all aspects of the design and construction of particle accelerators, including optics, emittance, luminosity, longitudinal and transverse beam dynamics, insertions, chromaticity, transfer lines, resonances, accelerating structures, tune shifts, coasting beams, lifetime, synchrotron radiation, radiation damping, beam-beam effects, diagnostics, cooling, ion and positron sources, RF and vacuum systems, injection and extraction, conventional, permanent and superconducting magnets, cyclotrons, RF linear accelerators, microtrons, as well as applications of particle accelerators (including therapy) and the history of accelerators. See hints under the relevant topics. (orig.)

  4. Gamma radiation and magnetic field mediated delay in effect of accelerated ageing of soybean

    International Nuclear Information System (INIS)

    Mahesh Kumar; Anand, Anjali; Singh, Bhupinder; Ahuja, Sumedha; Dahuja, Anil

    2015-01-01

    Soybean seeds were exposed to gamma radiation (0.5, 1, 3 and 5 kGy), static magnetic field (50, 100 and 200 mT) and a combination of gamma radiation and magnetic energy (0.5 kGy+200 mT and 5 kGy+50 mT) and stored at room temperature for six months. These seeds were later subjected to accelerated ageing treatment at 42°C temperature and 95-100 % relative humidity and were compared for various physical and biochemical characteristics between the untreated and the energized treatments. Energy treatment protected the quality of stored seeds in terms of its protein and oil content. Accelerated aging conditions, however, affected the oil and protein quantity and quality of seed negatively. Antioxidant enzymes exhibited a decline in their activity during aging while the LOX activity, which reflects the rate of lipid peroxidation, in general, increased during the aging. Gamma irradiated (3 and 5 kGy) and magnetic field treated seeds (100 and 200 mT) maintained a higher catalase and ascorbate peroxidase activity which may help in efficient scavenging of deleterious free radical produced during the aging. Aging caused peroxidative changes to lipids, which could be contributed to the loss of oil quality. Among the electromagnetic energy treatments, a dose of 1-5 kGy of gamma and 100 mT, 200 mT magnetic field effectively slowed the rate of biochemical degradation and loss of cellular integrity in seeds stored under conditions of accelerated aging and thus, protected the deterioration of seed quality. Energy combination treatments did not yield any additional protection advantage. (author)

  5. Two Step Acceleration Process of Electrons in the Outer Van Allen Radiation Belt by Time Domain Electric Field Bursts and Large Amplitude Chorus Waves

    Science.gov (United States)

    Agapitov, O. V.; Mozer, F.; Artemyev, A.; Krasnoselskikh, V.; Lejosne, S.

    2014-12-01

    A huge number of different non-linear structures (double layers, electron holes, non-linear whistlers, etc) have been observed by the electric field experiment on the Van Allen Probes in conjunction with relativistic electron acceleration in the Earth's outer radiation belt. These structures, found as short duration (~0.1 msec) quasi-periodic bursts of electric field in the high time resolution electric field waveform, have been called Time Domain Structures (TDS). They can quite effectively interact with radiation belt electrons. Due to the trapping of electrons into these non-linear structures, they are accelerated up to ~10 keV and their pitch angles are changed, especially for low energies (˜1 keV). Large amplitude electric field perturbations cause non-linear resonant trapping of electrons into the effective potential of the TDS and these electrons are then accelerated in the non-homogeneous magnetic field. These locally accelerated electrons create the "seed population" of several keV electrons that can be accelerated by coherent, large amplitude, upper band whistler waves to MeV energies in this two step acceleration process. All the elements of this chain acceleration mechanism have been observed by the Van Allen Probes.

  6. A study on radiation treatment of wastewater using an electron accelerator

    International Nuclear Information System (INIS)

    Hashimoto, Shoji

    1982-02-01

    A study on radiation oxidation treatment of refractory or toxic wastewater using an electron accelerator was carried out from the viewpoint of reaction engineering. For the process using electron beams, oxygen supply to the penetration range of electron (reaction zone) where the dose rate is extremely high, is significantly important. A concentric dual-tube-type bubbling column reactor was shown to be most suitable to maintain the dissolved oxygen at a high concentration. Rate expressions of pollutant reduction and oxygen consumption in the reactor were derived. The efficiency of active species utilization for oxidation, phi, was defined and shown to be an important design parameter. A new wastewater treatment system (Electron Accelerator-Dual tube Bubbling Reactor system) was proposed, and successfully demonstrated for the treatment of wastewater involving dyes and phenol. The dissolved oxygen was maintained at a high concentration by using this type of reactor for the high dose rate irradiation. phi was obtained as a function of dissolved oxygen concentration for the dye solution and was also obtained as functions of the oxygen concentration and dose rate for the phenol solution. By these experimental results, the effectiveness of EA-DBR system was proved. (author)

  7. NEOADJUVANT RADIOTHERAPY FOR BLADDER CARCINOMA IN ...

    African Journals Online (AJOL)

    Objective To evaluate the impact of preoperative accelerated hyperfractionated radiotherapy in the management of bladder carcinoma in Egyptian patients. Patients and Methods Between December 1996 and February 2000, 104 Egyptian patients with pathologically proven infiltrative bladder carcinoma were enrolled in ...

  8. Terahertz radiation from accelerating charge carriers in graphene under ultrafast photoexcitation

    Science.gov (United States)

    Rustagi, Avinash; Stanton, C. J.

    2016-11-01

    We study the generation of terahertz (THz) radiation from the acceleration of ultrafast photoexcited charge carriers in graphene in the presence of a dc electric field. Our model is based on calculating the transient current density from the time-dependent distribution function which is determined using the Boltzmann transport equation (BTE) within a relaxation time approximation. We include the time-dependent generation of carriers by the pump pulse by solving for the carrier generation rate using the optical Bloch equations in the rotating wave approximation (RWA). The linearly polarized pump pulse generates an anisotropic distribution of photoexcited carriers in the kx-ky plane. The collision integral in the Boltzmann equation includes a term that leads to the thermalization of carriers via carrier-carrier scattering to an effective temperature above the lattice temperature, as well as a cooling term, which leads to energy relaxation via inelastic carrier-phonon scattering. The radiated signal is proportional to the time derivative of the transient current density. In spite of the fact that the magnitude of the velocity is the same for all the carriers in graphene, there is still emitted radiation from the photoexcited charge carriers with frequency components in the THz range due to a change in the direction of velocity of the photoexcited carriers in the external electric field as well as cooling of the photoexcited carriers on a subpicosecond time scale.

  9. Accelerators

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

  10. Industrial use of electron accelerators

    International Nuclear Information System (INIS)

    Tabata, Y.

    1980-01-01

    Use of accelerators in various fields of Japan is reviewed. The total number of accelerators in Japan and its relation with others fields, the number of accelerators for use in radiation processing, comparison between the use of low and high energy machines, etc... is done. (E.G.) [pt

  11. Short and long term ionizing radiation effects on charge-coupled devices in radiation environment of high-intensity heavy ion accelerators

    International Nuclear Information System (INIS)

    Belousov, A; Mustafin, E; Ensinger, W

    2012-01-01

    Radiation effects on semiconductor devices is a topical issue for high-intensity accelerator projects. In particular it concerns Charge-Coupled Device (CCD) cameras, which are widely used for beam profile monitoring and surveillance in high radiation environment. One should have a clear idea of short and long term radiation effects on such devices. To study these effects, a CCD camera was placed in positions less than half meter away from beam loss point. Primary heavy ion beam of 0.95GeV/n Uranium was dumped into a thick aluminium target creating high fluences of secondary particles (e.g., gammas, neutrons, protons). Effects of these particles on CCD camera were scored with LabView based acquisition software. Monte Carlo calculations with FLUKA code were performed to obtain fluence distributions for different particles and make relevant comparisons. Long term total ionising dose effects are represented by dark current increase, which was scored throughout experiment. Instant radiation effects are represented by creation of charge in CCD cells by ionising particles. Relation of this charge to beam intensity was obtained for different camera positions and fluences within 5 orders of magnitude ranges. With high intensities this charge is so high that it may dramatically influence data obtained from CCD camera used in high radiation environment. The linearity of described above relation confirms linear response of CCD to ionizing radiation. It gives an opportunity to find a new application to CCD cameras as beam loss monitors (BLM).

  12. Safety guidance and inspection program for particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Do Whey [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Lee, Hee Seock; Yeo, In Whan [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)] (and others)

    2001-03-15

    The inspection program and the safety guidance were developed to enhance the radiation protection for the use of particle accelerators. First the classification of particle accelerators was conducted to develop the safety inspection protocol efficiently. The status of particle accelerators which were operated at the inside and outside of the country, and their safety programs were surveyed. The characteristics of radiation production was researched for each type of particle accelerators. Two research teams were launched for industrial and research accelerators and for medical accelerators, respectively. In each stages of a design, a fabrication, an installation, a commissioning, and normal operation of accelerators, those safety inspection protocols were developed. Because all protocols resulted from employing safety experts, doing the questionnaire, and direct facility surveys, it can be applicable to present safety problem directly. The detail improvement concepts were proposed to revise the domestic safety rule. This results might also be useful as a practical guidance for the radiation safety officer of an accelerator facility, and as the detail standard for the governmental inspection authorities.

  13. Liouville's equation and radiative acceleration in general relativity

    International Nuclear Information System (INIS)

    Keane, A.J.

    1999-01-01

    spacetimes. In the case of the Schwarzschild spacetime we find a solution of the Liouville equation which is invariant under the Killing vector symmetries and we adopt this as our model radiation field. Once a particular solution has been chosen the radiation field has been specified completely throughout the spacetime. In chapter 4 we investigate null and timelike geodesics in the Schwarzschild spacetime. Studying the null geodesics allows us to determine the viewing angles, that is, the (semi) angular size of the compact object as viewed by a stationary observer at an arbitrary point in the spacetime. The timelike geodesics are the trajectories of the (massive) test particles subject to no external radiation force and therefore constitute a limiting case of the radiative acceleration results. Given the radiation field one can calculate the radiation pressure force and because of special relativistic effects, the radiation pressure force experienced by the particle becomes velocity dependent. In chapter 5 we integrate the equations of motion for the case of purely radial motion in the Thomson limit. In this case we can obtain a tractable analytic expression for the solution in phase space, which can be compared with the high frequency case. In this chapter we consider a relativistic critical luminosity of a compact object, i.e. a relativistic Eddington luminosity. We also introduce and discuss terminal velocities and saturation velocities associated with a particular compact object. The terminal velocity of a radiation field is the 3-velocity required to annul the radiation pressure force on the test particle, neglecting the influence of any gravitational force on the particle. The saturation velocity is defined in the same way except the gravitational force is included. The saturation velocities are of course highly frequency dependent and provide important information about the dynamics of the system. In chapter 6 we discuss the Compton differential cross-section for

  14. Safety in design and operation of low energy particle accelerators

    International Nuclear Information System (INIS)

    Badawy, I.

    1991-01-01

    This paper studies the safety in design and operation of low energy accelerators which produce beams of accelerated charged particles and radiations. As radiation sources, the accelerators are widely used in scientific research, industry, food and medical applications. The risks to human and environment are considered. The safety in accelerators is discussed-particularly-the shielding against ionizing radiations, overexposure to RF radiation fire hazards and power failures. Also the paper studies the emergency response at incidents. Emergency procedures are recommended for each type of emergency. Reporting to the competent Authority is also recommended to be prepared for each incident. The basic principles of regulatory control, licensing and inspections for accelerator facilities are discussed. The relation with the competent authority is pointed out. 4 fig

  15. Accelerated hyperfractionated hepatic irradiation in the management of patients with liver metastases: Results of the RTOG dose escalating protocol

    International Nuclear Information System (INIS)

    Russell, A.H.; Clyde, C.; Wasserman, T.H.; Turner, S.S.; Rotman, M.

    1993-01-01

    This study was prepared to address two objectives: (a) to determine whether progressively higher total doses of hepatic irradiation can prolong survival in a selected population of patients with liver metastases and (b) to refine existing concepts of liver tolerance for fractionated external radiation. One hundred seventy-three analyzable patients with computed tomography measurable liver metastases from primary cancers of the gastrointestinal tract were entered on a dose escalating protocol of twice daily hepatic irradiation employing fractions of 1.5 Gy separated by 4 hr or longer. Sequential groups of patients received 27 Gy, 30 Gy, and 33 Gy to the entire liver and were monitored for acute and late toxicities, survival, and cause of death. Dose escalation was implemented following survival of 10 patients at each dose level for a period of 6 months or longer without clinical or biochemical evidence of radiation hepatitis. The use of progressively larger total doses of radiation did not prolong median survival or decrease the frequency with which liver metastases were the cause of death. None of 122 patients entered at the 27 Gy and 30 Gy dose levels revealed clinical or biochemical evidence of radiation induced liver injury. Five of 51 patients entered at the 33 Gy level revealed clinical or biochemical evidence of late liver injury with an actuarial risk of severe (Grade 3) radiation hepatitis of 10.0% at 6 months, resulting in closure of the study to patient entry. The study design could not credibly establish a safe dose for hepatic irradiation, however, it did succeed in determining that 33 Gy in fractions of 1.5 Gy is unsafe, carrying a substantial risk of delayed radiation injury. The absence of apparent late liver injury at the 27 Gy and 30 Gy dose levels suggests that a prior clinical trial of adjuvant hepatic irradiation in patients with resected colon cancer may have employed an insufficient radiation dose (21 Gy) to fully test the question

  16. Stability of a mobile electron linear accelerator system for intraoperative radiation therapy

    International Nuclear Information System (INIS)

    Beddar, A. Sam

    2005-01-01

    The flexibility of mobile electron accelerators, which are designed to be transported to an operating room and plugged into a normal 3-phase outlet, make them ideal for use in intraoperative radiation therapy. However, their transportability may cause trepidation among potential users, who may question the stability of such an accelerator over a period of use. In order to address this issue, we have studied the short-term stability of the Mobetron system over 20 daily quality assurance trials. Variations in output generally varied within ±2% for the four energies produced by the unit (4, 6, 9, and 12 MeV) and changes in energy produced an equivalent shift of less than 1 mm on the depth-dose curve. Hours of inactivity, with the Mobetron powered on for use either throughout the day or overnight, led to variations in output of about 1%. Finally, we have tested the long-term stability of the absolute dose output of the Mobetron, which showed a change of about 1% per year

  17. "Light sail" acceleration reexamined.

    Science.gov (United States)

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-08-21

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for "optimal" values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple "light sail" model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  18. 'Light Sail' Acceleration Reexamined

    International Nuclear Information System (INIS)

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-01-01

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for 'optimal' values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple 'light sail' model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  19. Application of a Pelletron accelerator to study total dose radiation effects on 50 GHz SiGe HBTs

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, K.C.; Pushpa, N.; Naik, P.S. [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India); Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Tripathi, Ambuj [Inter University Accelerator Centre (IUAC), New Delhi 110 067 (India); Gnana Prakash, A.P., E-mail: gnanaprakash@physics.uni-mysore.ac.in [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore 570 006 (India)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Total dose effects of 50 MeV Li3+ ion on 50 GHz SiGe HBTs is investigated. Black-Right-Pointing-Pointer Ion irradiated results were compared with Co-60 gamma results. Black-Right-Pointing-Pointer 50 MeV Li ions create more damage in E-B spacer oxide when compared to Co-60 gamma radiation. Black-Right-Pointing-Pointer Co-60 gamma radiation create more damage in STI oxide when compared to 50 MeV Li ions. Black-Right-Pointing-Pointer Worst case total dose radiation effects can be studied using Pelletron accelerator facilities. - Abstract: We have investigated the effects of 50 MeV lithium ion irradiation on the DC electrical characteristics of first-generation silicon-germanium heterojunction bipolar transistors (50 GHz SiGe HBTs) in the dose range of 600 krad to 100 Mrad. The results of 50 MeV Li{sup 3+} ion irradiation on the SiGe HBTs are compared with 63 MeV proton and Co-60 gamma irradiation results in the same dose range in order to understand the damage induced by different LET species. The radiation response of emitter-base (EB) spacer oxide and shallow trench isolation (STI) oxide to different irradiation types are discussed in this paper. We have also focused on the efficacy in the application of a Pelletron accelerator to study total dose irradiation studies in SiGe HBTs.

  20. Picosecond, single pulse electron linear accelerator

    International Nuclear Information System (INIS)

    Kikuchi, Riichi; Kawanishi, Masaharu

    1979-01-01

    The picosecond, single pulse electron linear accelerators, are described, which were installed in the Nuclear Engineering Laboratory of the University of Tokyo and in the Nuclear Radiation Laboratory of the Osaka University. The purpose of the picosecond, single pulse electron linear accelerators is to investigate the very short time reaction of the substances, into which gamma ray or electron beam enters. When the electrons in substances receive radiation energy, the electrons get high kinetic energy, and the energy and the electric charge shift, at last to the quasi-stable state. This transient state can be experimented with these special accelerators very accurately, during picoseconds, raising the accuracy of the time of incidence of radiation and also raising the accuracy of observation time. The outline of these picosecond, single pulse electron linear accelerators of the University of Tokyo and the Osaka University, including the history, the systems and components and the output beam characteristics, are explained. For example, the maximum energy 30 -- 35 MeV, the peak current 1 -- 8 n C, the pulse width 18 -- 40 ps, the pulse repetition rate 200 -- 720 pps, the energy spectrum 1 -- 1.8% and the output beam diameter 2 -- 5 mm are shown as the output beam characteristics of the accelerators in both universities. The investigations utilizing the picosecond single pulse electron linear accelerators, such as the investigation of short life excitation state by pulsed radiation, the dosimetry study of pulsed radiation, and the investigation of the transforming mechanism and the development of the transforming technology from picosecond, single pulse electron beam to X ray, vacuum ultraviolet ray and visual ray, are described. (Nakai, Y.)

  1. Radiation safety training for accelerator facilities

    International Nuclear Information System (INIS)

    Trinoskey, P.A.

    1997-02-01

    In November 1992, a working group was formed within the U.S. Department of Energy's (DOE's) accelerator facilities to develop a generic safety training program to meet the basic requirements for individuals working in accelerator facilities. This training, by necessity, includes sections for inserting facility-specific information. The resulting course materials were issued by DOE as a handbook under its technical standards in 1996. Because experimenters may be at a facility for only a short time and often at odd times during the day, the working group felt that computer-based training would be useful. To that end, Lawrence Livermore National Laboratory (LLNL) and Argonne National Laboratory (ANL) together have developed a computer-based safety training program for accelerator facilities. This interactive course not only enables trainees to receive facility- specific information, but time the training to their schedule and tailor it to their level of expertise

  2. Hyperfractionated craniospinal radiotherapy and adjuvant chemotherapy for children with newly diagnosed medulloblastoma and other primitive neuroectodermal tumors

    International Nuclear Information System (INIS)

    Allen, Jeffrey C.; Donahue, Bernadine; DaRosso, Robert; Nirenberg, Anita

    1996-01-01

    Purpose: This single-institution Phase I/II study conducted from 1989 to 1995 evaluates the feasibility of a multi-modality protocol combining hyperfractionated craniospinal radiotherapy (HFRT) followed by adjuvant chemotherapy in 23 patients with newly diagnosed primitive neuroectodermal tumors (PNET) arising in the central nervous system. Methods and Materials: All 23 patients had a histologically confirmed PNET and were over 3 years of age at diagnosis. The eligibility criteria for PNET patients with cerebellar primaries (medulloblastoma) included either a high T stage (T3b or 4) or high M stage (M1-3). All patients with noncerebellar primaries were eligible regardless of T or M stage. The median age of the 23 patients was 9 years (mean 3-25); 11 were female. The primary tumor arose in the cerebellum in 19. Of these medulloblastoma patients, 15 had high T stages (T3b or T4) with large locally invasive tumors and no evidence of metastases (M0), constituting Group 1. Thirteen (86%) of these patients had gross total resections. Four other medulloblastoma patients had both high T and high M stages, constituting Group 2. Group 3 consisted of four other patients with exocerebellar primaries (two brain, one brain stem, and one cauda equina), three of whom were M3. Hyperfractionated radiotherapy was administered within 4 weeks of surgery. Twice-daily 1-Gy fractions were administered separated by 4-6 h. The total dose to the primary intracranial tumor and other areas of measurable intracranial disease was 72 Gy. The prophylactic craniospinal axis dose was 36 Gy, and boosts of 44-56 Gy were administered to metastatic spinal deposits. Following radiotherapy, monthly courses of multiagent chemotherapy were administered sequentially (cyclophosphamide-vincristine followed by cisplatin-etoposide followed by carboplatin-vincristine) for a total of 9 months. Results: All patients completed radiotherapy as planned. Only three patients lost >10% of their body weight. One patient

  3. The Quality Control of Intensity Modulated Radiation Therapy (IMRT for ONCOR Siemens Linear Accelerators Using Film Dosimetry

    Directory of Open Access Journals (Sweden)

    Keyvan Jabbari

    2012-03-01

    Full Text Available Introduction Intensity Modulated Radiation Therapy (IMRT has made a significant progress in radiation therapy centers in recent years. In this method, each radiation beam is divided into many subfields that create a field with a modulated intensity. Considering the complexity of this method, the quality control for IMRT is a topic of interest for researchers. This article is about the various steps of planning and quality control of Siemens linear accelerators for IMRT, using film dosimetry. This article in addition to review of the techniques, discusses the details of experiments and possible sources of errors which are not mentioned in the protocols and other references. Materials and Methods This project was carried out in Isfahan Milad hospital which has two Siemens ONCOR linear accelerators. Both accelerators are equipped with Multi-Leaf Collimators (MLC which enables us to perform IMRT delivery in the step-and-shoot method. The quality control consists of various experiments related to the sections of radiation therapy. In these experiments, the accuracy of some components such as treatment planning system, imaging device (CT, MLC, control system of accelerator, and stability of the output are evaluated. The dose verification is performed using film dosimetry method. The films were KODAK-EDR2, which were calibrated before the experiments. One of the important steps is the comparison of the calculated dose with planning system and the measured dose in experiments. Results The results of the experiments in various steps have been acceptable according to the standard protocols. The calibration of MLC and evaluation of the leakage through the leaves of MLC was performed by using the film dosimetry and visual check. In comparison with calculated and measured dose, more that 80% of the points have to be in agreement within 3% of the value. In our experiments, between 85 and 90% of the points had such an agreement with IMRT delivery. Conclusion

  4. Imaging response is highly predictive of survival of malignant glioma patients treated with standard or hyperfractionated RT and carmustine in RTOG 9006

    International Nuclear Information System (INIS)

    Curran, Walter J.; Scott, Charles B.; Yung, W.K. Alfred; Scarantino, Charles; Urtasun, Raul; Movsas, Benjamin; Jones, Christopher; Simpson, Joseph; Fischbach, A. Jennifer; Petito, Carol; Nelson, James

    1996-01-01

    Objectives: Limited information is available correlating response to initial therapy and survival outcome among malignant glioma patients. This analysis was conducted to determine the response rate of malignant glioma patients to either standard (STN) or hyperfractionated (HFX) RT and carmustine and to correlate the tumor response status with survival. Patients and Methods: From (11(90)) to (3(94)), 712 newly diagnosed malignant glioma patients were registered on RTOG 9006 and randomized between hyperfractionated RT of 72.0 Gy in 1.2 Gy twice-daily fractions and 60.0 Gy in 2.0 Gy daily fractions. All patients received 80 mg/m-2 of carmustine D 1-3 q 8 wks. As reported in the 1996 Proceedings of the Amer Soc Clin Oncol (Abstr no. 280), there was no survival benefit observed for the HFX regimen. 529 of the 686 eligible patients had pre-operative, post-operative, and post-RT contrast-enhanced MR and/or CT scans available for central review of tumor and peritumoral edema measurements. Response status was judged by applying standard response criteria to a comparison of tumor measurements on follow-up and post-operative films. Results: Of the 529 patients evaluated for imaging response, the complete and partial response rates were 14% and 20%, respectively. A significant correlation between response and survival was observed (P<0.0001). Variables which predicted for a better tumor response were anaplastic astrocytoma vs glioblastoma multiforme histology, better performance status, more extensive resection, and a more favorable Recursive Partitioning and Amalgamation class assignment (JNCI 85:704-710, 1993). Conclusion: The objective response rate for malignant glioma patients to RTOG 9006 therapy was 34%, and survival outcome is strongly correlated with tumor response status. These observations justify the testing of aggressive salvage strategies for patients without imaging evidence of response following initial therapy

  5. Radiation protection activities around the CERN accelerators

    International Nuclear Information System (INIS)

    Silari, M.

    1998-01-01

    In 1997 the physics programme of the SPS and LEP was seriously affected by a fire in one of the surface building of the SPS; the incident caused a delay in the LEP start-up, an interruption of several weeks in the SPS fixed-target programme, and the cancellation of the lead ion run for 1997. The consequences for the experiments were, nevertheless, kept to a minimum thanks to the excellent performance of the accelerators. The neutrino experiments even accumulated a record intensity. Experiments at the ISOLDE facility benefited from 315 shifts instead of 200 as originally scheduled, and new experiments started measuring the properties of unstable elements which play a crucial role in the stars. LEP also reached record energy and luminosity in 1997. Measurements of synchrotron radiation in the LEP tunnel were repeated at the new energy value of 92 GeV, to comply with the demands of the INB procedure. Following the end of operation of ACOL and LEAR in December 1996, decommissioning of the Antiproton Accumulator and transformation of the Antiproton Collector into the Antiproton Decelerator started. Experiments in the South Hall were dismantled during the year and the hall will be used partly as a storage area for radioactive components and partly as a test area

  6. Radiation-Pressure Acceleration of Ion Beams from Nanofoil Targets: The Leaky Light-Sail Regime

    International Nuclear Information System (INIS)

    Qiao, B.; Zepf, M.; Borghesi, M.; Dromey, B.; Geissler, M.; Karmakar, A.; Gibbon, P.

    2010-01-01

    A new ion radiation-pressure acceleration regime, the 'leaky light sail', is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10 19 W/cm 2 . 100 MeV proton beams are obtained by increasing the intensities to 2x10 20 W/cm 2 .

  7. Radiation-pressure acceleration of ion beams from nanofoil targets: the leaky light-sail regime.

    Science.gov (United States)

    Qiao, B; Zepf, M; Borghesi, M; Dromey, B; Geissler, M; Karmakar, A; Gibbon, P

    2010-10-08

    A new ion radiation-pressure acceleration regime, the "leaky light sail," is proposed which uses sub-skin-depth nanometer foils irradiated by circularly polarized laser pulses. In the regime, the foil is partially transparent, continuously leaking electrons out along with the transmitted laser field. This feature can be exploited by a multispecies nanofoil configuration to stabilize the acceleration of the light ion component, supplementing the latter with an excess of electrons leaked from those associated with the heavy ions to avoid Coulomb explosion. It is shown by 2D particle-in-cell simulations that a monoenergetic proton beam with energy 18 MeV is produced by circularly polarized lasers at intensities of just 10¹⁹  W/cm². 100 MeV proton beams are obtained by increasing the intensities to 2 × 10²⁰  W/cm².

  8. Applying the accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Barbalat, Oscar

    1989-12-15

    Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology.

  9. Applying the accelerator

    International Nuclear Information System (INIS)

    Barbalat, Oscar

    1989-01-01

    Originally developed as tools for frontier physics, particle accelerators provide valuable spinoff benefits in applied research and technology. These accelerator applications are the subject of a biennial meeting in Denton, Texas, but the increasing activity in this field resulted this year (5-9 September) in the first European Conference on Accelerators in Applied Research and Technology, organized by K. Bethge of Frankfurt's Goethe University. The meeting reflected a wide range of applications - ion beam analysis, exploitation of nuclear microbeams, accelerator mass spectrometry, applications of photonuclear reactions, ion beam processing, synchrotron radiation for semiconductor technology, specialized technology

  10. Monte Carlo simulations and benchmark studies at CERN's accelerator chain

    CERN Document Server

    AUTHOR|(CDS)2083190; Brugger, Markus

    2016-01-01

    Mixed particle and energy radiation fields present at the Large Hadron Collider (LHC) and its accelerator chain are responsible for failures on electronic devices located in the vicinity of the accelerator beam lines. These radiation effects on electronics and, more generally, the overall radiation damage issues have a direct impact on component and system lifetimes, as well as on maintenance requirements and radiation exposure to personnel who have to intervene and fix existing faults. The radiation environments and respective radiation damage issues along the CERN’s accelerator chain were studied in the framework of the CERN Radiation to Electronics (R2E) project and are hereby presented. The important interplay between Monte Carlo simulations and radiation monitoring is also highlighted.

  11. Hadron accelerators in cancer therapy

    International Nuclear Information System (INIS)

    Amaldi, U.; Silari, M.

    1997-01-01

    The application of hadron accelerators (protons and light ions) in cancer therapy is discussed. After a brief introduction on the rationale for the use of heavy charged particles in radiation therapy, a discussion is given on accelerator technology and beam delivery systems. Next, existing and planned facilities are briefly reviewed. The Italian Hadrontherapy Project (the largest project of this type in Europe) is then described, with reference to both the National Centre for Oncological Hadrontherapy and the design of two types of compact proton accelerators aimed at introducing proton therapy in a large number of hospitals. Finally, the radiation protection requirements are discussed. (author)

  12. The Radiological Research Accelerator Facility

    International Nuclear Information System (INIS)

    Hall, E.J.; Marino, S.A.

    1990-07-01

    The Radiological Research Accelerator Facility (RARAF) is based on a 4-MV Van de Graaff accelerator, which is used to generate a variety of well-characterized radiation beams for research in radiobiology, radiological physics, and radiation chemistry. It is part of the Center for Radiological Research (CRR) -- formerly the Radiological Research Laboratory (RRL) -- of Columbia University, and its operation is supported as a National Facility by the US Department of Energy (DOE). Fifteen different experiments were run during these 12 months, approximately the same as the previous two years. Brief summaries of each experiment are included. Accelerator usage is summarized and development activities are discussed. 7 refs., 4 tabs

  13. Intensity modulated radiation therapy using laser-accelerated protons: a Monte Carlo dosimetric study

    International Nuclear Information System (INIS)

    Fourkal, E; Li, J S; Xiong, W; Nahum, A; Ma, C-M

    2003-01-01

    In this paper we present Monte Carlo studies of intensity modulated radiation therapy using laser-accelerated proton beams. Laser-accelerated protons coming out of a solid high-density target have broad energy and angular spectra leading to dose distributions that cannot be directly used for therapeutic applications. Through the introduction of a spectrometer-like particle selection system that delivers small pencil beams of protons with desired energy spectra it is feasible to use laser-accelerated protons for intensity modulated radiotherapy. The method presented in this paper is a three-dimensional modulation in which the proton energy spectrum and intensity of each individual beamlet are modulated to yield a homogeneous dose in both the longitudinal and lateral directions. As an evaluation of the efficacy of this method, it has been applied to two prostate cases using a variety of beam arrangements. We have performed a comparison study between intensity modulated photon plans and those for laser-accelerated protons. For identical beam arrangements and the same optimization parameters, proton plans exhibit superior coverage of the target and sparing of neighbouring critical structures. Dose-volume histogram analysis of the resulting dose distributions shows up to 50% reduction of dose to the critical structures. As the number of fields is decreased, the proton modality exhibits a better preservation of the optimization requirements on the target and critical structures. It is shown that for a two-beam arrangement (parallel-opposed) it is possible to achieve both superior target coverage with 5% dose inhomogeneity within the target and excellent sparing of surrounding tissue

  14. Leakage of radioactive materials from particle accelerator facilities by non-radiation disasters like fire and flooding and its environmental impacts

    Science.gov (United States)

    Lee, A.; Jung, N. S.; Mokhtari Oranj, L.; Lee, H. S.

    2018-06-01

    The leakage of radioactive materials generated at particle accelerator facilities is one of the important issues in the view of radiation safety. In this study, fire and flooding at particle accelerator facilities were considered as the non-radiation disasters which result in the leakage of radioactive materials. To analyse the expected effects at each disaster, the case study on fired and flooded particle accelerator facilities was carried out with the property investigation of interesting materials presented in the accelerator tunnel and the activity estimation. Five major materials in the tunnel were investigated: dust, insulators, concrete, metals and paints. The activation levels on the concerned materials were calculated using several Monte Carlo codes (MCNPX 2.7+SP-FISPACT 2007, FLUKA 2011.4c and PHITS 2.64+DCHAIN-SP 2001). The impact weight to environment was estimated for the different beam particles (electron, proton, carbon and uranium) and the different beam energies (100, 430, 600 and 1000 MeV/nucleon). With the consideration of the leakage path of radioactive materials due to fire and flooding, the activation level of selected materials, and the impacts to the environment were evaluated. In the case of flooding, dust, concrete and metal were found as a considerable object. In the case of fire event, dust, insulator and paint were the major concerns. As expected, the influence of normal fire and flooding at electron accelerator facilities would be relatively low for both cases.

  15. Berkeley Lab Laser Accelerator (BELLA) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Berkeley Lab Laser Accelerator (BELLA) facility (formerly LOASIS) develops advanced accelerators and radiation sources. High gradient (1-100 GV/m) laser-plasma...

  16. Acceleration theorems

    International Nuclear Information System (INIS)

    Palmer, R.

    1994-06-01

    Electromagnetic fields can be separated into near and far components. Near fields are extensions of static fields. They do not radiate, and they fall off more rapidly from a source than far fields. Near fields can accelerate particles, but the ratio of acceleration to source fields at a distance R, is always less than R/λ or 1, whichever is smaller. Far fields can be represented as sums of plane parallel, transversely polarized waves that travel at the velocity of light. A single such wave in a vacuum cannot give continuous acceleration, and it is shown that no sums of such waves can give net first order acceleration. This theorem is proven in three different ways; each method showing a different aspect of the situation

  17. SHEAR ACCELERATION IN EXPANDING FLOWS

    Energy Technology Data Exchange (ETDEWEB)

    Rieger, F. M. [ZAH, Institut für Theoretische Astrophysik, Universität Heidelberg, Philosophenweg 12, D-69120 Heidelberg (Germany); Duffy, P., E-mail: frank.rieger@mpi-hd.mpg.de, E-mail: peter.duffy@ucd.ie [University College Dublin, Belfield, Dublin 4 (Ireland)

    2016-12-10

    Shear flows are naturally expected to occur in astrophysical environments and potential sites of continuous non-thermal Fermi-type particle acceleration. Here we investigate the efficiency of expanding relativistic outflows to facilitate the acceleration of energetic charged particles to higher energies. To this end, the gradual shear acceleration coefficient is derived based on an analytical treatment. The results are applied to the context of the relativistic jets from active galactic nuclei. The inferred acceleration timescale is investigated for a variety of conical flow profiles (i.e., power law, Gaussian, Fermi–Dirac) and compared to the relevant radiative and non-radiative loss timescales. The results exemplify that relativistic shear flows are capable of boosting cosmic-rays to extreme energies. Efficient electron acceleration, on the other hand, requires weak magnetic fields and may thus be accompanied by a delayed onset of particle energization and affect the overall jet appearance (e.g., core, ridge line, and limb-brightening).

  18. Radiation vulcanization of rubbers

    Energy Technology Data Exchange (ETDEWEB)

    Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-02-01

    An abstract of the radiation process of polymer materials and the polymer reaction by radiation is explained. Main radiation is 250 keV to 10 MeV of electron rays in the industry. Radiation cross-linked rubber has less the tensile strength than that by sulfur and organic peroxide crosslinking. The main origins of low tensile strength are caused by cut of backbone chain and ozone depend on radiation. Acceleration of crosslinking and short time of radiation are necessary to improve these defects. To accelerate crosslinking, we used crosslinking accelerators, for example, three poly-functional monomers (PFM). The maximum tensile strength of styrene-butadiene rubber (SBR) not added crosslinking accelerators showed 3 MPa at 110 kGy, but SBR added A-TMMT (tetramethylolmethane tetraacrylate) showed 5.5 MPa at 110 kGy. Radiation crosslinking of many kinds of rubber: isoprene (IR), SBR, CR, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), butyl rubber (IIR), chlorinated butyl rubber (CIIR), EPM and TPE are explained. (S.Y.)

  19. Radiation vulcanization of rubbers

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2002-01-01

    An abstract of the radiation process of polymer materials and the polymer reaction by radiation is explained. Main radiation is 250 keV to 10 MeV of electron rays in the industry. Radiation cross-linked rubber has less the tensile strength than that by sulfur and organic peroxide crosslinking. The main origins of low tensile strength are caused by cut of backbone chain and ozone depend on radiation. Acceleration of crosslinking and short time of radiation are necessary to improve these defects. To accelerate crosslinking, we used crosslinking accelerators, for example, three poly-functional monomers (PFM). The maximum tensile strength of styrene-butadiene rubber (SBR) not added crosslinking accelerators showed 3 MPa at 110 kGy, but SBR added A-TMMT (tetramethylolmethane tetraacrylate) showed 5.5 MPa at 110 kGy. Radiation crosslinking of many kinds of rubber: isoprene (IR), SBR, CR, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), butyl rubber (IIR), chlorinated butyl rubber (CIIR), EPM and TPE are explained. (S.Y.)

  20. Optimization of radiation protection for an electron accelerator used in paint cure in films approved by Brazilian Nuclear Energy Commission - CNEN, Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Rios, Denise A. da S.; Sordi, Gian Maria A.A.

    2014-01-01

    This study aims to evaluate the radiological protection system in an installation where there is a self-shielded accelerator Category I, used for paint curing in polymer films, in order to optimize it in situations in which it is appropriate. For this a radiometric survey was conducted in the designated areas to check rate doses at different distances from the radiation focus, in which there is a possibility of presence or persons which can reliably detect any abnormality in the accelerator operation. The comparison of the obtained values related to the accelerator operating current with the natural background radiation showed that they are compatible, signaling that the principle of optimization is already being followed

  1. Electron accelerators: History, applications, and perspectives

    International Nuclear Information System (INIS)

    Martins, M.N.; Silva, T.F.

    2014-01-01

    This paper will present an outlook on sources of radiation, focusing on electron accelerators. We will review advances that were important for the development of particle accelerators, concentrating on those that led to modern electron accelerators. Electron accelerators are multipurpose machines that deliver beams with energies spanning five orders of magnitude, and are used in applications that range from fundamental studies of particle interactions to cross-linking polymer chains in industrial plants. Each accelerator type presents specific characteristics that make it more suitable for certain applications. Our work will focus on radiation sources for medical applications, dominated by electron linacs (linear accelerators), and those used for research, field where electron rings dominate. We will outline the main technological advances that occurred in the past decades, which made possible the construction of machines fit for clinical environments. Their compactness, efficiency and reliability have been key to their acceptance in clinical applications. This outline will include advances that allowed for the construction of brighter synchrotron light sources, where the relevant beam characteristics are good optical quality and high beam current. The development of insertion devices will also be discussed, as well the development of Free Electron Lasers (FEL). We conclude the review with an outline of the new developments of electron accelerators and the expectations for Energy Recovery Linacs. - Highlights: ► We present an outlook on sources of radiation, focusing on electron accelerators. ► We review important advances for the development of modern electron accelerators. ► We outline advances that allowed for brighter synchrotron light sources. ► We describe the history of the development of electron accelerators in Brazil

  2. Accelerators for cancer therapy

    International Nuclear Information System (INIS)

    Lennox, Arlene J.

    2000-01-01

    The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy

  3. An accelerating reference frame for electromagnetic waves in a rapidly growing plasma

    International Nuclear Information System (INIS)

    Yablonovitch, E.

    1989-01-01

    In 1974, Hawking showed that black holes can evaporate by the emission of low temperature thermal radiation, now named Hawking radiation. Shortly thereafter, a closely related effect called Unruh radiation became apparent. The author discusses how, according to Unruh and Davies, observers of the electromagnetic field in an accelerating reference frame should see thermal radiation at a temperature T: KT = h/2π a/c where a is the acceleration relative to an inertial frame, c is the speed of light and h and K are Planck's and Boltzmann's constant respectively. In a frame accelerating at g = 980 cm/sec 2 , equivalent to the acceleration experienced at the earth's surface, this thermal radiation is at a temperature of only 4 x 10 -20 degrees K. Therefore, physicists hoping to observe this radiation, have sought out systems being subjected to extreme acceleration

  4. Industrial applications of electron accelerators

    International Nuclear Information System (INIS)

    Singh, A.

    1994-01-01

    The interaction of high-energy radiation with organic systems produces very reactive, short-lived, ionic and free-radical species. The chemical changes brought about by these species are very useful in several systems, and are the basis of the growth of the electron processing industry. Some typical areas of the industrial use of electron accelerators are crosslinking wire and cable insulation, manufacturing heat shrink plastic items, curing coatings, and partially curing rubber products. Electron accelerators are also being considered in other areas such as sewage treatment, sterilizing medical disposables, and food irradiation. An emerging application of industrial electron accelerators is the production of advanced composites for the aerospace and other industries. Traditionally, the carbon-, aramid- and glass-fibre-reinforced composites with epoxy matrices are produced by thermal curing. However, equivalent composites with acrylated-epoxy matrices can be made by electron curing. Cost estimates suggest that electron curing could be more economical than thermal curing. Food irradiation has traditionally been an application for 60 Co γ-radiation. With the increasing demand for food irradiation in various countries, it may become necessary to use electron accelerators for this purpose. Since the dose rate during gamma and electron irradiation are generally very different, a review of the relevant work on the effect of dose rates has been done. This paper presents an overview of the industrial applications of electron accelerator for radiation processing, emphasises the electron curing of advanced composites and, briefly reviews the dose-rate effects in radiation processing of advanced composites and food irradiation. (author). 84 refs., 8 tabs

  5. Monte Carlo design, dosimetry and radiation protection studies for a new mobile electron accelerator for intraoperative radiation therapy (IORT)

    International Nuclear Information System (INIS)

    Wysocka-Rabin, A.

    2013-01-01

    Intraoperative radiation therapy (IORT) delivers a large, single fraction dose of radiation to a surgically exposed tumor or tumor bed. This presentation reviews the design concept and dosimetry characteristics of an electron beam forming system for an IORT accelerator, with special emphasis on beam flatness, X-ray contamination and protecting personnel from dose delivered outside the treatment field. The Monte Carlo code, BEAMnrc/EGSnrc, was used to design, verify and optimize the electron beam forming system for two different docking methods with circular metallic applicators. Calculations of therapeutic beam characteristics were performed at the patient surface. Findings were obtained for initially mono-energetic electron beams with an energy range from 4 to 12 MeV, SSD equal to 60 cm, and circular applicators with diameters from 3 to 12 cm. The aim was to build an electron beam forming system (collimators, scattering-flattening foils, applicators) that is universal for all beam energy and field diameters described above

  6. Accelerator safety program at the Lawrence Livermore Laboratory

    International Nuclear Information System (INIS)

    Graham, C.L.

    1976-01-01

    A proposed accelerator safety standard for the Lawrence Livermore Laboratory (LLL) is given. All accelerators will comply with this standard when it is included in the LLL Health and Safety Manual. The radiation alarm and radiation safety system for a radiography facility are also described

  7. CAS CERN Accelerator School second advanced accelerator physics course

    International Nuclear Information System (INIS)

    Turner, S.

    1989-01-01

    The advanced course on general accelerator physics given in West Berlin closely followed that organised by the CERN Accelerator School at Oxford in September 1985 and whose proceedings were published as CERN Yellow Report 87-03 (1987). However, certain subjects were treated in a different way, improved or extended, while some new ones were introduced and it is all of these which are included in the present proceedings. The lectures include particle-photon interactions, high-brilliance lattices and single/multiple Touschek effect, while the seminars are on the major accelerators presently under construction or proposed for the near future, applications of synchrotron radiation, free-electron lasers, cosmic accelerators and crystal beams. Also included are errata, and addenda to some of the lectures, of CERN 87-03. (orig.)

  8. Accelerator programme at CAT

    International Nuclear Information System (INIS)

    Ramamurthi, S.S.

    1991-01-01

    The Accelerator Programme at the Centre for Advanced Technology (CAT), Indore, has very broad based concept under which all types of accelerators are to be taken up for design and fabrication. This centre will be housing a wide variety of accelerators to serve as a common facility for the universities, national laboratories in addition to laboratories under the Department of Atomic Energy. In the first phase of the programme, a series of electron accelerators are designed and fabricated. They are synchrotron radiation sources of 450 MeV (INDUS-I) and of 2 GeV (INDUS-II), microtron upto energy of 20 MeV, linear accelerator upto 20 MeV, and DC Accelerator for industrial irradiation upto 750 KeV and 20 KW. A proton accelerator of 300 MeV with 20 MeV linac injector is also designed. CAT is also developing a strong base for support technologies like ultra high vacuum, radio frequency and microwaves, DC pulsed and superconducting magnets, power supplies and controls etc. These technologies are very useful for other industrial applications also. To develop user groups to utilise INDUS-II synchrotron radiation source, a batch production of rotating Anode X-ray generators with power supplies has been initiated. So also, the sputter ion pumps, electron guns, turbo molecular pumps are brought into batch production. (author)

  9. The decommissioning of accelerator installations, a challenge for radiation protection in the 21st century

    International Nuclear Information System (INIS)

    Hoefert, M.; Forkel-Wirth, D.

    2000-01-01

    One major challenge that accelerator health physicists will face in the 21st century is the decommissioning of sometimes big accelerator installations that have come of age and will be dismantled. The problem of the rather special kind of radioactive material produced as a result of the operation of accelerators has only lately found the necessary attention. In fact, the question of what to do with the quantities of radioactive material that are generated by accelerators during operation and at the time of dismantling had so far been pushed aside as, admittedly, also in the field of radiation protection it is more interesting to plan and build new accelerators than to decommission old installations. Radioactive material in the form of waste has a bad reputation with the general public particularly since the final storage of the highly radioactive waste from the nuclear cycle is still not solved. When discussing radioactive waste from accelerators the first aim therefore is to clearly point out the important differences in the nature and the risk potential of reactor and accelerator waste. Accelerator waste is activated in the bulk and not surface-contaminated. It contains no high atomic number alpha emitters and is in its great majority of rather low specific activity. With this information at hand it is obvious that recycling of the mostly metallic radioactive material from the accelerator environment is not only reasonable but also the most economic approach. Hence, the efforts to define on an international scale radionuclide specific clearance levels are appreciated. They are analyzed with respect to their hesitant introduction into national laws and their practical application is discussed with respect to radioactive material from accelerators. Here, an unsolved problem is the missing knowledge about the composition of radionuclides due to the fact that radioactive products as the result of high-energy spallation reactions from the accelerator environment will

  10. Accelerators in industrial and clinical practice

    International Nuclear Information System (INIS)

    Kulinich, S.

    1983-01-01

    Various possible accelerator applications in the USSR are given, namely the use of a linear electron accelerator in crack detection of thick-walled steel products, the use of accelerators in the radiation-chemical production of antimicrobial fabrics, the use of a pulsed electron accelerator for the disinfection of sewage waters, the use of accelerators for the treatment of tumors. Instruments have been developed on the basis of linear electron accelerators for the activation analysis of ores. (M.D.)

  11. Salivary gland function of nasopharyngeal cancer patients treated by simultaneous modulated accelerated radiation therapy

    International Nuclear Information System (INIS)

    Zhang Qi; Li Huanbin; Wang Ling

    2007-01-01

    The work was to study protective effect of simultaneous modulated accelerated radiation therapy (SMART) on salivary function of nasopharyngeal cancer patients. Forty-six patients were treated by SMART with 2.5Gy/fraction at gross tumor volume to a total does of 70 Gy, and 2.0 Gy/fraction at the clinical treatment volume to a total does of 56 Gy. The SMART was practiced in step-and-shoot mode, one time a day, and five times each week. Fourteen patients were treated by conventional radiation therapy. All the patients received salivary gland function imaging for their uptake index, excretive index and excretive speed, so as to evaluate their degree of salivary function injury. Meanwhile, the dry discomfort in mouth of the patients was recorded and classified. The results showed that the functional indexes of the SMART group were significantly higher than those of the conventional radiation therapy group (P 2 =23.52, P<0.005). Therefore, SMART can play a key role in protecting salivary gland function of naso- pharyngeal cancer patients. (authors)

  12. Simple method for routine check of the constancy of radiation quality of bremsstrahlung emitted by therapeutic particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Rassow, J; Eipper, H H; Krause, K [Essen Univ. (Gesamthochschule) (Germany, F.R.). Abt. fuer Klinische Strahlenphysik; Staedtisches Krankenhaus Koeln-Merheim (Germany, F.R.). Roentgeninstitut und Strahlenklinik)

    1977-05-01

    The constancy of the radiation quality of therapeutically employed particle accelerators has to be checked at weekly intervals. Any change in radiation quality may have considerable therapeutic effects owing to its influence on dose distribution. It is recommended that measurements be made instead of, or in addition to, the axial reference-point measurement at 5 and 15 cm depth in the phantom, at 5 cm depth in the beam axis and at a reference-point about 1 cm within the geometric edge of the field, for checking the constancy of the radiation quality of bremsstrahlung. Only then, if routine checks carried out for the axial and the lateral reference-point dose ratios do not show any deviations greater than e.g. +-2 %, radiation quality is deemed to have remained sufficiently constant for radiotherapeutical applications.

  13. Electron acceleration in the bubble regime

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, Oliver

    2014-02-03

    The bubble regime of laser-wakefield acceleration has been studied over the recent years as an important alternative to classical accelerators. Several models and theories have been published, in particular a theory which provides scaling laws for acceleration parameters such as energy gain and acceleration length. This thesis deals with numerical simulations within the bubble regime, their comparison to these scaling laws and data obtained from experiments, as well as some specific phenomenona. With a comparison of the scaling laws with numerical results a parameter scan was able to show a large parameter space in which simulation and theory agree. An investigation of the limits of this parameter space revealed boundaries to other regimes, especially at very high (a{sub 0} > 100) and very low laser amplitudes (a{sub 0} < 4). Comparing simulation data with data from experiments concerning laser pulse development and electron energies, it was found that experimental results can be adequately reproduced using the Virtual-Laser-Plasma-Laboratory code. In collaboration with the Institut fuer Optik und Quantenelektronik at the Friedrich-Schiller University Jena synchrotron radiation emitted from the inside of the bubble was investigated. A simulation of the movement of the electrons inside the bubble together with time dependent histograms of the emitted radiation helped to prove that the majority of radiation created during a bubble acceleration originates from the inside of the bubble. This radiation can be used to diagnose the amplitude of oscillation of the trapped electrons. During a further study it was proven that the polarisation of synchrotron radiation from a bubble contains information about the exact oscillation direction. This oscillation was successfully controlled by using either a laser pulse with a tilted pulse front or an asymmetric laser pulse. First results of ongoing studies concerning injecting electrons into an existing bubble and a scheme called

  14. A study on leakage radiation dose at ELV-4 electron accelerator bunker

    Science.gov (United States)

    Chulan, Mohd Rizal Md; Yahaya, Redzuwan; Ghazali, Abu BakarMhd

    2014-09-01

    Shielding is an important aspect in the safety of an accelerator and the most important aspects of a bunker shielding is the door. The bunker's door should be designed properly to minimize the leakage radiation and shall not exceed the permitted limit of 2.5μSv/hr. In determining the leakage radiation dose that passed through the door and gaps between the door and the wall, 2-dimensional manual calculations are often used. This method is hard to perform because visual 2-dimensional is limited and is also very difficult in the real situation. Therefore estimation values are normally performed. In doing so, the construction cost would be higher because of overestimate or underestimate which require costly modification to the bunker. Therefore in this study, two methods are introduced to overcome the problem such as simulation using MCNPX Version 2.6.0 software and manual calculation using 3-dimensional model from Autodesk Inventor 2010 software. The values from the two methods were eventually compared to the real values from direct measurements using Ludlum Model 3 with Model 44-9 probe survey meter.

  15. Radiological protection at particle accelerators: An overview

    International Nuclear Information System (INIS)

    Thomas, R.H.

    1991-01-01

    Radiological protection began with particle accelerators. Many of the concerns in the health physics profession today were discovered at accelerator laboratories. Since the mid-1940s, our understanding has progressed through seven stages: observation of high radiation levels; shielding; development of dosimetric techniques; studies of induced activity and environmental impact; legislative and regulatory concerns; and disposal. The technical and scientific aspects of accelerator radiation safety are well in hand. In the US, there is an urgent need to move away from a ''best available technology'' philosophy to risk-based health protection standards. The newer accelerators will present interesting radiological protection issues, including copious muon production and high LET (neutron) environments

  16. The electron accelerator in industry - safety aspects

    International Nuclear Information System (INIS)

    Kirthi, K.N.

    1993-01-01

    Electron beam accelerators are being used in increasing numbers in a variety of important applications. Commercial uses include radiography, food preservation, product sterilisation and radiation processing of materials. Since most of the industrial applications involve products, some that can be treated with electrons and others that require photons, electron accelerators serve this dual purpose economically. Although industrial accelerators are now regarded as standard products, finished installations show considerable diversity, reflecting the users, needs and planning. Because of the high radiation output, proper planning regarding safety is warranted. This paper discusses the hazards, safety and planning required during design and operation of the electron beam accelerators. (author). 4 refs., 1 fig

  17. Accelerated aging tests of radiation damaged lasers and photodiodes for the CMS tracker optical links

    CERN Document Server

    Gill, K; Batten, J; Cervelli, G; Grabit, R; Jensen, F; Troska, Jan K; Vasey, F

    1999-01-01

    The combined effects of radiation damage and accelerated ageing in COTS lasers and p-i-n photodiodes are presented. Large numbers of these devices are employed in future High Energy Physics experiments and it is vital that these devices are confirmed to be sufficiently robust in terms of both radiation resistance and reliability. Forty 1310 nm InGaAsP edge-emitting lasers (20 irradiated) and 30 InGaAs p- i-n photodiodes (19 irradiated) were aged for 4000 hours at 80 degrees C with periodic measurements made of laser threshold and efficiency, in addition to p-i-n leakage current and photocurrent. There were no sudden failures and there was very little wearout- related degradation in either unirradiated or irradiated sample groups. The results suggest that the tested devices have a sufficiently long lifetime to operate for at least 10 years inside the Compact Muon Solenoid experiment despite being exposed to a harsh radiation environment. (13 refs).

  18. Several problems in accelerator shielding study

    International Nuclear Information System (INIS)

    Nakamura, Takashi; Hirayama, Hideo; Ban, Shuichi.

    1980-01-01

    Recently, the utilization of accelerators has increased rapidly, and the increase of accelerating energy and beam intensity is also remarkable. The studies on accelerator shielding have become important, because the amount of radiation emitted from accelerators increased, the regulation of the dose of environmental radiation was tightened, and the cost of constructing shielding rose. As the plans of constructing large accelerators have been made successively, the survey on the present state and the problems of the studies on accelerator shielding was carried out. Accelerators are classified into electron accelerators and proton accelerators in view of the studies on shielding. In order to start the studies on accelerator shielding, first, the preparation of the cross section data is indispensable. The cross sections for generating Bremsstrahlung, photonuclear reactions generating neutrons, generation of neutrons by hadrons, nuclear reaction of neutrons and generation of gamma-ray by hadrons are described. The generation of neutrons and gamma-ray as the problems of thick targets is explained. The shielding problems are complex and diversified, but in this paper, the studies on the shielding, by which basic data are obtainable, are taken up, such as beam damping and side wall shielding. As for residual radioactivity, main nuclides and the difference of residual radioactivity according to substances have been studied. (J.P.N.)

  19. Beam dosimetry in high-power electron accelerators

    International Nuclear Information System (INIS)

    Popov, V.N.; Zhitomirskii, B.M.; Ermakov, A.N.; Terebilin, A.V.; Stryukov, V.A.

    1987-01-01

    In order to evaluate beam utilization efficiency, measure the radiation yield, and determine the cost effectiveness of the new technologies, it is necessary to know the radiation power of the electron beam absorbed by the reacting medium. To measure the electron-beam power the authors designed, built, and tested a radiation detector combining a Faraday cylinder with a continuous-flow calorimeter. The construction of the detector is shown. The radiation detector was tested on a number of electron accelerators. The beam-power and mean-electron-energy measurement results for the LUE-8M accelerator with 8 MeV maximum electron energy are given

  20. Secondary radiation from supervoltage accelerators - its implications in patient protection

    International Nuclear Information System (INIS)

    Bhatnagar, J.P.

    1977-01-01

    If the collimator and compensator of a supervoltage accelerator are made of high atomic number material they will tend to interact with the high energy photon beam predominantly by pair production. Associated with pair-production is a cascade formation resulting in a variety of radiations which may be serious from the point of view of patient protection, particularly if the field of treatment is close to some superficially located critical organ such as the lens of the eye or the gonads. Gonadal doses of about 15% of the mid-depth dose were measured on a young male patient undergoing treatment of the prostate by a 42MV X-ray beam from a Siemen's betatron. A lead block 1.5 cm thick placed over the patient's thighs covering the scrotum reduced the gonadal dose to less than 2% of the mid-depth dose. A similar set of measurements made on a specially constructed scrotum-penis phantom confirmed these results, and showed that the lead block must be placed close to the phantom to be effective. Comparative measurements made just outside a cobalt 60 beam showed that the doses were far smaller than those outside the 42MeV X-ray beam. Recommendations are therefore made for the thickness and positioning of lead shielding required to protect critical organs from secondary radiation in radiotherapy. (U.K.)

  1. Secondary malignancies in patients with stage IA-IIIA Hodgkin's lymphoma after radiation (chemoradiation) therapy using accelerated dose fractionation

    International Nuclear Information System (INIS)

    Sinajko, V.V.; Minajlo, I.I.; Veyakin, I.V.

    2010-01-01

    The incidence of secondary malignancies was investigated in 367 patients with stage IA-IIIA Hodgkin's lymphoma after radiation therapy using accelerated fractionation. For 20 years of the observation 24 of them developed 27(7.4%) tumors, besides their frequency did not depend on the disease stage and method of treatment.

  2. Towards MRI-guided linear accelerator control: gating on an MRI accelerator.

    Science.gov (United States)

    Crijns, S P M; Kok, J G M; Lagendijk, J J W; Raaymakers, B W

    2011-08-07

    To boost the possibilities of image guidance in radiotherapy by providing images with superior soft-tissue contrast during treatment, we pursue diagnostic quality MRI functionality integrated with a linear accelerator. Large respiration-induced semi-periodic target excursions hamper treatment of cancer of the abdominal organs. Methods to compensate in real time for such motion are gating and tracking. These strategies are most effective in cases where anatomic motion can be visualized directly, which supports the use of an integrated MRI accelerator. We establish here an infrastructure needed to realize gated radiation delivery based on MR feedback and demonstrate its potential as a first step towards more advanced image guidance techniques. The position of a phantom subjected to one-dimensional periodic translation is tracked with the MR scanner. Real-time communication with the MR scanner and control of the radiation beam are established. Based on the time-resolved position of the phantom, gated radiation delivery to the phantom is realized. Dose distributions for dynamic delivery conditions with varying gating windows are recorded on gafchromic film. The similarity between dynamically and statically obtained dose profiles gradually increases as the gating window is decreased. With gating windows of 5 mm, we obtain sharp dose profiles. We validate our gating implementation by comparing measured dose profiles to theoretical profiles calculated using the knowledge of the imposed motion pattern. Excellent correspondence is observed. At the same time, we show that real-time on-line reconstruction of the accumulated dose can be performed using time-resolved target position information. This facilitates plan adaptation not only on a fraction-to-fraction scale but also during one fraction, which is especially valuable in highly accelerated treatment strategies. With the currently established framework and upcoming improvements to our prototype-integrated MRI accelerator

  3. Physics and Novel Schemes of Laser Radiation Pressure Acceleration for Quasi-monoenergetic Proton Generation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chuan S. [Univ. of Maryland, College Park, MD (United States). Dept. of Physics; Shao, Xi [Univ. of Maryland, College Park, MD (United States)

    2016-06-14

    The main objective of our work is to provide theoretical basis and modeling support for the design and experimental setup of compact laser proton accelerator to produce high quality proton beams tunable with energy from 50 to 250 MeV using short pulse sub-petawatt laser. We performed theoretical and computational studies of energy scaling and Raleigh--Taylor instability development in laser radiation pressure acceleration (RPA) and developed novel RPA-based schemes to remedy/suppress instabilities for high-quality quasimonoenergetic proton beam generation as we proposed. During the project period, we published nine peer-reviewed journal papers and made twenty conference presentations including six invited talks on our work. The project supported one graduate student who received his PhD degree in physics in 2013 and supported two post-doctoral associates. We also mentored three high school students and one undergraduate student of physics major by inspiring their interests and having them involved in the project.

  4. From nGy to MGy - new TL dosimetry of complex radiation at high-energy accelerators and thermonuclear fusion facilities

    International Nuclear Information System (INIS)

    Obryk, B.; Bilski, P.; Budzanowski, M.; Olko, P.

    2011-01-01

    One of the well known advantages of thermoluminescence (TL) detectors made of lithium fluoride doped with magnesium, copper and phosphorus (LiF:Mg,Cu,P) is their very high sensitivity to ionizing radiation. LiF:Mg,Cu,P detectors enable measurements of radiation doses from tens of nano grays up to a few kilo grays, when the total saturation of the signal of the so-called main dosimetric peak (at about 220 C. degrees) occurs. In 2006 for the first time we observed unprecedented high-temperature emission of LiF detectors heated to temperatures up to 600 C. degrees, after exposures to radiation doses ranging from 1 kGy to 1 MGy. For quantification of the glow curve shape changes of LiF:Mg,Cu,P detectors in this range of doses and determination of the absorbed dose, the high temperature coefficient (UHTR) was defined. This newly established dosimetric method was tested in a range of radiation qualities, such as gamma radiation, electron and proton beams, thermal neutron fields and in high-energy mixed fields around the SPS and PS accelerators at CERN. A number of dosimetric sets with LiF:Mg,Cu,P detectors are currently installed around the LHC at CERN. The new method for ultra-high dose range monitoring with a single LiF:Mg,Cu,P detector, which is capable of covering at least twelve orders of magnitude of doses, can be used for dosimetry at high energy accelerators and has great potential for accident dosimetry in particular. (authors)

  5. Radiation therapy for intracranial ependymomas: impact of age on outcome

    International Nuclear Information System (INIS)

    Pham, Houng T.; Sneed, Penny K.; Wara, William M.; Edwards, Michael S.; Wilson, Charles B.; Larson, David A.

    1997-01-01

    Purpose: The records of patients with intracranial ependymoma who received radiation therapy at UCSF were reviewed retrospectively to evaluate the impact of Karnofsky performance status (KPS), age, histology, and treatment on outcome. Materials and Methods: Between 1978 and 1996, 45 patients with intracranial ependymoma received postoperative radiation therapy. Overall survival (OS) and progression free survival (PFS) were calculated from the date of diagnosis. Median follow up for surviving patients was 72 months. Ages ranged from 4 months to 56 years, with a median of 8 years. The tumor was infratentorial in 35 and supratentorial in 10. All patients had either biopsy (3), subtotal resection (30), or gross total resection (12). There were 29 low grade and 16 anaplastic ependymomas. Thirty-seven patients received standard fractionation to a median dose of 54 Gy. Eight patients received hyperfractionation at 1.0 Gy BID to a median dose of 72 Gy. Thirty-eight patients had partial brain irradiation and seven had craniospinal irradiation. Twenty-three patients received adjuvant chemotherapy. For the infants ≤ 3 years old (n=12), all but one had a subtotal resection and most received chemotherapy prior to radiation therapy. Seven infants received radiation therapy at the time of disease progression and five had radiation therapy prior to progression. Most of the patients > 3 years old were irradiated prior to progression. Results: The five-year actuarial OS and PFS were 65% and 46% for the whole group. Histology and treatment factors such as extent of resection, hyperfractionation, and adjuvant chemotherapy did not significantly affect outcome. Overall, (25(45)) patients had disease progression. Only two patients failed in the brain outside the primary site. Six patients developed leptomeningeal spread (four concurrent with local failure and two subsequent to local failure). Five-year OS for patients ≤ 3 years old was 21% versus 80% for patients > 3 years old (p=0

  6. Health physics practices at research accelerators

    International Nuclear Information System (INIS)

    Thomas, R.H.

    1976-02-01

    A review is given of the uses of particle accelerators in health physics, the text being a short course given at the Health Physics Society Ninth Midyear Topical Symposium in February, 1976. Topics discussed include: (1) the radiation environment of high energy accelerators; (2) dosimetry at research accelerators; (3) shielding; (4) induced activity; (5) environmental impact of high energy accelerators; (6) population dose equivalent calculation; and (7) the application of the ''as low as practicable concept'' at accelerators

  7. Efficacy of post operative adjuvant therapy with human interferon beta, MCNU and radiation (IMR) for malignant glioma: comparison among three protocols

    International Nuclear Information System (INIS)

    Hatano, N.; Wakabayashi, T.; Kajita, Y.; Mizuno, M.; Ohno, T.; Nakayashiki, N.; Takemura, A.; Yoshida, J.

    2000-01-01

    In order to develop ultimate adjuvant therapy for malignant gliomas, we analyzed 77 patients with malignant gliomas (29 anaplastic astrocytomas (AAs) and 48 glioblastoma multiformes (GMs)) treated by three protocols of IMR therapy (human interferon-beta (HuIFN-β), MCNU and radiation). In protocol 1 (n = 45 : AA = 13, GM = 32), 1 x 10 6 IU of HuIFN-β was administrated intravenously once a day for 7 days. On day 2, MCNU was administrated at a dose of 2 mg/kg b.w. intravenously and from day 3, radiation was started in five weekly fractions of 2 Gy for 6 weeks. Total dose was 60 Gy. Protocol 2 (n = 19 : AA = 11, GM = 8) was comparable with protocol 1 except HuIFN-β was administrated twice a day at a dose of 1 x 10 6 IU each. Protocol 3 (n = 13 : AA = 5, GM = 8) differed from protocol 2 only in a high dose-hyperfractionated radiation which was given twice a day at a dose of 1.5 Gy each and for a total dose of 66 Gy. Antitumor effects were evaluated by survival and response rate determined by decrease of tumor size. Significant improvement was obtained in patients with AAs by protocol 2 and 3. Response rates of patients with AAs and GMs were 46.2 % and 50 % in protocol 1, 63.6 % and 50 % in protocol 2, and 80 % and 50 % in protocol 3, respectively. One and two year survival rates in AAs were 46.4 % and 34.8 % in protocol 1, both 75 % in protocol 2, and both 100 % in protocol 3. Survival rates in GMs were not different among them. Except of radiation necrosis, which was observed in 38.5 % of the patients under protocol 3, there was no significant difference in the adverse effects among the three protocols. In the present study, the efficacy of IMR therapy for patients with malignant gliomas, especially for AAs, was confirmed. We conclude that twice a day administrations of HuIFN-β in combination with a high dose-hyperfractionated radiation provide increased efficacy in IMR therapy. (author)

  8. Feasibility of Optical Transition Radiation Imaging for Laser-driven Plasma Accelerator Electron-Beam Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A. H. [Fermilab; Rule, D. W. [Unlisted, US, MD; Downer, M. C. [Texas U.

    2017-10-09

    We report the initial considerations of using linearly polarized optical transition radiation (OTR) to characterize the electron beams of laser plasma accelerators (LPAs) such as at the Univ. of Texas at Austin. The two LPAs operate at 100 MeV and 2-GeV, and they currently have estimated normalized emittances at ~ 1-mm mrad regime with beam divergences less than 1/γ and beam sizes to be determined at the micron level. Analytical modeling results indicate the feasibility of using these OTR techniques for the LPA applications.

  9. Dosimetric commissioning and system for stereotactic radiation treatments based on linear accelerators with dynamic micromultilaminas collimators

    International Nuclear Information System (INIS)

    Ascension, Yudy; Alfonso, Rodolfo; Silvestre, Ileana

    2009-01-01

    Once installed and accepted, a system for stereotactic radiosurgery / stereotactic radiotherapy (CERs / RTE) requires, before starting to be used clinically in patients undergoing a process of commissioning dosimetry, which evaluates all geometric parameters, physical, Dosimetric and technical impact on the precision and accuracy of treatment to administer, and therefore its effectiveness. This process includes training and familiarization of the multidisciplinary team (medical physicists, radiation oncologists, neurosurgeons, dosimetrists, biomedical engineers) with the equipment and techniques used, the quality assurance program and special radiation protection standards for this technology. The aim of this work is to prepare the pre-clinical dosimetric conditions to ensure the quality and radiation safety of treatment with CER RTE. Treatment with CER RTE INOR has a linear accelerator equipped with a micro-multileaf collimator dynamic tertiary (dMLC 3Dline). The system aceleradordMLC geometric and dosimetric was calibrated, using ionization chambers miniature, diode and film dosimetry. The immobilization of the patient and location of the lesion is made by both invasive stereotactic frames and relocatable. The computerized planning of the CER / TEN is done with the ERGO system, for which commissioning is designed test cases of increasing complexity, using planes and anthropomorphic dummies, which help assess the accuracy of the dosimetric calculations and accuracy of the system as a whole. We compared the results of the planning system with measurements, showing that the discrepancies are within tolerances, so it is concluded that from the standpoint of physical dosimetry, the system-under-ERGO accelerator MLC is eligible for clinical use. (author)

  10. An ultrashort pulse ultra-violet radiation undulator source driven by a laser plasma wakefield accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Anania, M. P. [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); INFN, Laboratori Nazionali di Frascati, I-00044 Frascati (Italy); Brunetti, E.; Wiggins, S. M.; Grant, D. W.; Welsh, G. H.; Issac, R. C.; Cipiccia, S.; Shanks, R. P.; Manahan, G. G.; Aniculaesei, C.; Jaroszynski, D. A., E-mail: d.a.jaroszynski@strath.ac.uk [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Geer, S. B. van der; Loos, M. J. de [Pulsar Physics, Burghstraat 47, 5614 BC Eindhoven (Netherlands); Poole, M. W.; Shepherd, B. J. A.; Clarke, J. A. [ASTeC, STFC, Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Gillespie, W. A. [SUPA, School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); MacLeod, A. M. [School of Computing and Creative Technologies, University of Abertay Dundee, Dundee DD1 1HG (United Kingdom)

    2014-06-30

    Narrow band undulator radiation tuneable over the wavelength range of 150–260 nm has been produced by short electron bunches from a 2 mm long laser plasma wakefield accelerator based on a 20 TW femtosecond laser system. The number of photons measured is up to 9 × 10{sup 6} per shot for a 100 period undulator, with a mean peak brilliance of 1 × 10{sup 18} photons/s/mrad{sup 2}/mm{sup 2}/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120–130 MeV with the radiation pulse duration in the range of 50–100 fs.

  11. Heavy ion accelerators for inertial fusion

    International Nuclear Information System (INIS)

    Rubbia, C.

    1992-01-01

    Particle accelerators are used for accelerating the elementary, stable and separable constituents of matters to relativistic speed. These beams are of fundamental interest in the study on the ultimate constituents of matters and their interaction. Particle accelerators are the most promising driver for the fusion power reactors based on inertial confinement. The principle of inertial confinement fusion, radiation driven indirect drive, the accelerator complex and so on are described. (K.I.)

  12. Physics and technical development of accelerators

    International Nuclear Information System (INIS)

    2000-03-01

    About 90 registered participants delivered more than 40 scientific papers. A great part of these presentations were of general interest about running projects such as CIME accelerator at Ganil, IPHI (high intensity proton injector), ESRF (European source of synchrotron radiation), LHC (large hadron collider), ELYSE accelerator at Orsay, AIRIX, and VIVITRON tandem accelerator. Other presentations highlighted the latest technological developments of accelerator components: superconducting cavities, power klystrons, high current injectors..

  13. Application of TSEE characteristics to high energy radiation dosimetry around an electron linear accelerator

    International Nuclear Information System (INIS)

    Yamamoto, T.; Nakasaku, S.; Kawanishi, M.

    1986-01-01

    The response of the exoelectron dosemeter to the absorbed dose has been investigated with the LiF sample irradiated with high energy electrons from a linear accelerator and γ rays from a 60 Co source. The energy absorbed in the thin surface layer, which can be related to the origins of exoelectron emission, is, in general, smaller than the energy liberated there by primary radiation. In this paper the surface dose is calculated by the Monte Carlo Code EGS4. It is pointed out that the air layer in front of the sample also plays an important role by supplying secondary electrons to the surface region of the sample. The emission density of exoelectrons from a LiF single crystal for unit absorbed dose is found to be 5 x 10 4 electrons.cm -2 .Gy -1 , and nearly constant independent of the low LET radiation type. (author)

  14. Accelerator mass spectrometry and associated facilities at Inter-University Accelerator Centre, New Delhi, India

    International Nuclear Information System (INIS)

    Kumar, Pankaj; Bohra, Archna; Ojha, S.; Gargari, S.; Joshi, R.; Roonwal, G.S.; Chopra, S.; Pattanaik, J.K.; Balakrishnan, S.

    2011-01-01

    Accelerator Mass Spectrometry (AMS) facility at Inter-University Accelerator Centre (IUAC) is developed by upgrading its existing 15UD Pelletron accelerator. Since last two decades Pelletron is mainly used for nuclear physics, materials science, atomic physics, radiation biology and accelerator mass spectrometry is recent development. In addition, a chemistry laboratory in clean room for the chemical processing of samples for AMS studies has also been established. At present the AMS facility is used for 10 Be, 26 Al measurements and soon other long lived radio-isotopes will also be used

  15. Laser-driven particle acceleration towards radiobiology and medicine

    CERN Document Server

    2016-01-01

    This book deals with the new method of laser-driven acceleration for application to radiation biophysics and medicine. It provides multidisciplinary contributions from world leading scientist in order to assess the state of the art of innovative tools for radiation biology research and medical applications of ionizing radiation. The book contains insightful contributions on highly topical aspects of spatio-temporal radiation biophysics, evolving over several orders of magnitude, typically from femtosecond and sub-micrometer scales. Particular attention is devoted to the emerging technology of laser-driven particle accelerators and their applicatio to spatio-temporal radiation biology and medical physics, customization of non-conventional and selective radiotherapy and optimized radioprotection protocols.

  16. Design and implementation of a device for measuring radiation energy of an electron accelerator

    International Nuclear Information System (INIS)

    Salhi, Heythem; Selmi, Samir

    2010-01-01

    Our work is part of a graduation project at the School of Technology and Computing, to obtain a master's degree in electrical engineering specialty industrial computer. Throughout the four-month internship at the National Center for Nuclear Science and Technology (CNSTN), we have learned to practice the knowledge acquired during the formative years and to manage our working time. Our job was to design and implementation of a device for measuring the energy of radiation. Our project meets the needs of users in the radio treatment Unit, which amount to automate measurement of radiation energy from the electron accelerator. This project has been beneficial on several levels: it was an opportunity to achieve better control of printed circuits, especially when they are dual layer and learning a new programming language that is actually BASIC. In human terms, this work has given us the opportunity to learn to manage our time, and learn teamwork. However, we are convinced that this project can be enhanced on various levels. It can be considered as a starting point of a contribution to the real-time measurement of the energy of radiation.

  17. Analysis of the power system from an electron beam accelerator and the correlation with the theoretical dosimetry for radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Somessari, Samir Luiz; Somessari, Elizabeth S. Ribeiro; Silveira, Carlos Gaia da; Calvo, Wilson Aparecido Parejo, E-mail: somessar@ipen.br, E-mail: esomessa@ipen.br, E-mail: cgsilvei@ipen.br, E-mail: wapcalvo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Dynamitron DC1500/25/04 type electron beam accelerator (EBA), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN/CNEN-SP in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: for sterilization of medical, pharmaceutical and biological products; treatment of industrial and domestic effluents and sludge; preservation and disinfestation of foods and agricultural products; lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel; decontamination of pesticide packing; solid residues remediation; organic compounds removal from wastewater; treatment of effluent from petroleum production units; crosslinking of foams, wires and electric cables; composite and nanocomposite materials and carbon fibers irradiation; irradiated grafting ion-exchange membranes for fuel cells application; natural polymers and multilayer packages irradiation, and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the point of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC1500/25/04 accelerator, such as, voltage and root-mean-square (RMS) current in the oscillator system, high voltage generator and waveform, using software developed in the

  18. Analysis of the power system from an electron beam accelerator and the correlation with the theoretical dosimetry for radiation processing

    International Nuclear Information System (INIS)

    Somessari, Samir Luiz; Somessari, Elizabeth S. Ribeiro; Silveira, Carlos Gaia da; Calvo, Wilson Aparecido Parejo

    2013-01-01

    Dynamitron DC1500/25/04 type electron beam accelerator (EBA), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN/CNEN-SP in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: for sterilization of medical, pharmaceutical and biological products; treatment of industrial and domestic effluents and sludge; preservation and disinfestation of foods and agricultural products; lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel; decontamination of pesticide packing; solid residues remediation; organic compounds removal from wastewater; treatment of effluent from petroleum production units; crosslinking of foams, wires and electric cables; composite and nanocomposite materials and carbon fibers irradiation; irradiated grafting ion-exchange membranes for fuel cells application; natural polymers and multilayer packages irradiation, and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the point of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC1500/25/04 accelerator, such as, voltage and root-mean-square (RMS) current in the oscillator system, high voltage generator and waveform, using software developed in the

  19. TH-A-BRD-01: Radiation Biology for Radiation Therapy Physicists

    International Nuclear Information System (INIS)

    Orton, C; Borras, C; Carlson, D

    2014-01-01

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how

  20. TH-A-BRD-01: Radiation Biology for Radiation Therapy Physicists

    Energy Technology Data Exchange (ETDEWEB)

    Orton, C [Wayne State University, Grosse Pointe, MI (United States); Borras, C [Radiological Physics and Health Services, Washington, DC (United States); Carlson, D [Yale University School of Medicine, New Haven, CT (United States)

    2014-06-15

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how

  1. Exploration of phase stability in the surfatron accelerator

    International Nuclear Information System (INIS)

    Neuffer, D.V.

    1984-04-01

    Proton and electron motion in a laser beat-wave accelerator with a transverse magnetic field is explored. Parameters of stable acceleration are determined analytically and by simulation. The effects of synchrotron radiation on electron acceleration are also explored

  2. A study on leakage radiation dose at ELV-4 electron accelerator bunker

    Energy Technology Data Exchange (ETDEWEB)

    Chulan, Mohd Rizal Md, E-mail: rizal@nuclearmalaysia.gov.my, E-mail: redzuwan@ukm.my; Yahaya, Redzuwan, E-mail: rizal@nuclearmalaysia.gov.my, E-mail: redzuwan@ukm.my [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (Malaysia); Ghazali, Abu BakarMhd [Department of Electronic and Communication, College of Engineering, Universiti Tenaga Nasional (Malaysia)

    2014-09-03

    Shielding is an important aspect in the safety of an accelerator and the most important aspects of a bunker shielding is the door. The bunker’s door should be designed properly to minimize the leakage radiation and shall not exceed the permitted limit of 2.5μSv/hr. In determining the leakage radiation dose that passed through the door and gaps between the door and the wall, 2-dimensional manual calculations are often used. This method is hard to perform because visual 2-dimensional is limited and is also very difficult in the real situation. Therefore estimation values are normally performed. In doing so, the construction cost would be higher because of overestimate or underestimate which require costly modification to the bunker. Therefore in this study, two methods are introduced to overcome the problem such as simulation using MCNPX Version 2.6.0 software and manual calculation using 3-dimensional model from Autodesk Inventor 2010 software. The values from the two methods were eventually compared to the real values from direct measurements using Ludlum Model 3 with Model 44-9 probe survey meter.

  3. A study on leakage radiation dose at ELV-4 electron accelerator bunker

    International Nuclear Information System (INIS)

    Chulan, Mohd Rizal Md; Yahaya, Redzuwan; Ghazali, Abu BakarMhd

    2014-01-01

    Shielding is an important aspect in the safety of an accelerator and the most important aspects of a bunker shielding is the door. The bunker’s door should be designed properly to minimize the leakage radiation and shall not exceed the permitted limit of 2.5μSv/hr. In determining the leakage radiation dose that passed through the door and gaps between the door and the wall, 2-dimensional manual calculations are often used. This method is hard to perform because visual 2-dimensional is limited and is also very difficult in the real situation. Therefore estimation values are normally performed. In doing so, the construction cost would be higher because of overestimate or underestimate which require costly modification to the bunker. Therefore in this study, two methods are introduced to overcome the problem such as simulation using MCNPX Version 2.6.0 software and manual calculation using 3-dimensional model from Autodesk Inventor 2010 software. The values from the two methods were eventually compared to the real values from direct measurements using Ludlum Model 3 with Model 44-9 probe survey meter

  4. Accelerator for medical applications and electron acceleration by laser plasma

    International Nuclear Information System (INIS)

    Hosokai, Tomonao; Uesaka, Mitsuru

    2006-01-01

    In this article, the current status of radiation therapies in Japan and updated medical accelerators are reviewed. For medical use, there is a strong demand of a compact and flexible accelerator. At present, however, we have only two choices of the S-band linac with one or two rotation axis combined with the multi leaf collimator, or the X-band linac with a rather flexible robotic arm. In addition, the laser plasma cathode that is the second generation of the laser wake-field accelerator (LWFA) is studied as a high-quality electron source for medical use though it is still at the stage of the basic research. The potential of LWFA as medical accelerator near future is discussed based on updated results of laser plasma cathode experiment in Univ. of Tokyo. (author)

  5. Accelerator X-ray sources

    International Nuclear Information System (INIS)

    Talman, R.

    2006-01-01

    This is the first monograph to cover in-depth the production of brilliant x-ray beams in accelerators, with emphasis on fourth generation designs, such as energy recovery linacs (ERL), fast cycling storage rings, and free electron lasers (FEL). Going beyond existing treatments of the influence of synchroton radiation on accelerator operation, special emphasis is placed on the design of undulator-based beam lines, and the physics of undulator radiation. Starting from the unified treatment of electron and photon beams both as bunches of particles and as waves, the author proceeds to analyse the main components, from electron gun, through linac and arc lattice, to the x-ray beam line. Designs are given for both an ERL and a more conventional storage ring complex, and their anticipated properties are compared in detail. Space charge effects are analysed with emphasis on coherent synchrotron radiation and emittance dilution. Beam diagnostics using synchrotron radiation or laser wire (Compton scattering) are also analysed in detail. Written primarily for general, particle, and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers. (orig.)

  6. Materials for heavy current accelerators and their alteration under scattered protons resulted from acceleration and secondary radiations

    International Nuclear Information System (INIS)

    L'vov, A.N.; Sidorenko, I.S.; Khizhnyak, N.A.; Shilyaev, B.A.; Yamnitskij, V.A.

    1983-01-01

    Changes of macroscopic properties of materials for new generation accelerators during irradiation by spill protons and secondary radiations have been analyzed. It is shown, that the change in properties is a result of many interrelated processes: nuclear ones, in which initially knocked out atoms (IKA) and products of nuclear reactions (especially helium and hydrogen) are formed, atomic ones consisting in the development of cascade collisions induced by IKA and resulting in the formation of initial regions of point defects accumulation; structural ones, resulting in the formation ssociations of defects, pores, dislocations and in the processes of creep, swelling, embrittlement etc. Each process is deccribed by a model and is realized by a computer code. The full program complex is written in the FORTRAN and ALGOL (GDR) for the BEhSM-6 and EC-1040 computers. Total number of standard code library exceeds 20 thousand operators, the memory size of base data is about 10 megabyte

  7. Shielding experiments for accelerator facilities

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Hiroshi; Tanaka, Susumu; Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2000-06-01

    A series of shielding experiments was carried out by using AVF cyclotron accelerator of TIARA at JAERI in order to validate shielding design methods for accelerator facilities in intermediate energy region. In this paper neutron transmission experiment through thick shields and radiation streaming experiment through a labyrinth are reported. (author)

  8. Shielding experiments for accelerator facilities

    International Nuclear Information System (INIS)

    Nakashima, Hiroshi; Tanaka, Susumu; Sakamoto, Yukio

    2000-01-01

    A series of shielding experiments was carried out by using AVF cyclotron accelerator of TIARA at JAERI in order to validate shielding design methods for accelerator facilities in intermediate energy region. In this paper neutron transmission experiment through thick shields and radiation streaming experiment through a labyrinth are reported. (author)

  9. The Brookhaven National Laboratory Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.

    1992-01-01

    The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies

  10. Accelerator control systems in China

    International Nuclear Information System (INIS)

    Yao Chihyuan

    1992-01-01

    Three accelerator facilities were built in the past few years, the 2.8 GeV electron positron collider BEPC, the heavy ion SSC cyclotron accelerator HIRFL and the 800 MeV synchrotron radiation storage ring HESYRL. Aimed at different research areas, they represent a new generation of accelerator in China. This report describes the design philosophy, the structure, performance as well as future improvements of the control systems of the these facilities. (author)

  11. Enhanced efficiency of plasma acceleration in the laser-induced cavity pressure acceleration scheme

    International Nuclear Information System (INIS)

    Badziak, J; Rosiński, M; Jabłoński, S; Pisarczyk, T; Chodukowski, T; Parys, P; Rączka, P; Krousky, E; Ullschmied, J; Liska, R; Kucharik, M

    2015-01-01

    Among various methods for the acceleration of dense plasmas the mechanism called laser-induced cavity pressure acceleration (LICPA) is capable of achieving the highest energetic efficiency. In the LICPA scheme, a projectile placed in a cavity is accelerated along a guiding channel by the laser-induced thermal plasma pressure or by the radiation pressure of an intense laser radiation trapped in the cavity. This arrangement leads to a significant enhancement of the hydrodynamic or electromagnetic forces driving the projectile, relative to standard laser acceleration schemes. The aim of this paper is to review recent experimental and numerical works on LICPA with the emphasis on the acceleration of heavy plasma macroparticles and dense ion beams. The main experimental part concerns the research carried out at the kilojoule sub-nanosecond PALS laser facility in Prague. Our measurements performed at this facility, supported by advanced two-dimensional hydrodynamic simulations, have demonstrated that the LICPA accelerator working in the long-pulse hydrodynamic regime can be a highly efficient tool for the acceleration of heavy plasma macroparticles to hyper-velocities and the generation of ultra-high-pressure (>100 Mbar) shocks through the collision of the macroparticle with a solid target. The energetic efficiency of the macroparticle acceleration and the shock generation has been found to be significantly higher than that for other laser-based methods used so far. Using particle-in-cell simulations it is shown that the LICPA scheme is highly efficient also in the short-pulse high-intensity regime and, in particular, may be used for production of intense ion beams of multi-MeV to GeV ion energies with the energetic efficiency of tens of per cent, much higher than for conventional laser acceleration schemes. (paper)

  12. Laser-plasma accelerators, acceleration of particles through laser-matter interaction at ultra-high intensity

    International Nuclear Information System (INIS)

    Lefebvre, E.

    2010-01-01

    This series of slides overviews the development of powerful lasers for inertial confinement fusion (Icf) at NIF (National Ignition Facility, Usa) and LMJ (Laser Megajoule, France) facilities. Then the principle of laser wakefield acceleration is presented and the possibility of designing compact accelerators delivering 200 GeV/m while conventional RF accelerators reach only 50 MeV/m, is considered. This technical breakthrough will bring important gains in terms of size, cost and new uses for accelerators. While Icf will use nanosecond (10 -9 s) laser pulses, wakefield accelerators will use femtosecond (10 -15 s) laser pulses which means more power but less energy. The electrons accelerated by laser can produce a multi-MeV X radiation useful for industrial radiography or cancer treatment. (A.C.)

  13. Radiation impact caused by activation of air from the future GSI accelerator facility fair

    International Nuclear Information System (INIS)

    Gutermuth, F.; Wildermuth, H.; Radon, T.; Fehrenbacher, G.

    2005-01-01

    The Gesellschaft fuer Schwerionenforschung in Darmstadt is planning a new accelerator Facility for Antiproton and Ion Research (FAIR). Two future experimental areas are regarded to be the most decisive points concerning the activation of air. One is the area for the production of antiprotons. A second crucial experimental area is the so-called Super Fragment Separator. The production of radioactive isotopes in air is calculated using the residual nuclei option of the Monte Carlo program FLUKA. The results are compared with the data for the activation of air given by Sullivan and in IAEA report 283. The resulting effective dose is calculated using a program package from the German Federal Office for Radiation Protection, the Bundesamt fuer Stranlenschutz. The results demonstrate that a direct emission of the total radioactivity produced into the air will probably conflict with the limits of the German Radiation Protection Ordinance. Special measures have to be planned in order to reduce the amount of radioactivity released into the air. (authors)

  14. Recommendations for standardized diagnostics, treatment and following care in tumor diseases. Diagnostics and therapy of tumor pain

    International Nuclear Information System (INIS)

    Drings, P.; Isele, H.; Zimmermann, M.

    2001-01-01

    The paper presents different methods for treatment of the cancer pain. Radiotherapy is applicable for treatment of skeleton metastases and accompanying symptoms. Bone metastases are mainly due to six types of tumors: breast, lung, prostate, thyroid gland, kidney and bladder carcinoma. The pain relief mechanisms of low and high dose irradiation are different - low dose radiation has a direct (chemical) analgetic effect and high dose radiation leads to a restrain of the tumor growth and a remineralisation which contributes to pain relief, too. The treatment is with the routine fractionated irradiation with daily dose of 2Gy up to a total dose of 40Gy for 4 weeks. Other possible treatments are: accelerated fractionated irradiation with 15-20 Gy weekly or 30 Gy for 2 weeks, and hyper-fractionated with 2 -3 irradiations daily. After the radiotherapy a total elimination of the pain is observed in 50% of the cases and a significant reducing - in 30-40%

  15. CAS CERN Accelerator School. Third advanced accelerator physics course

    International Nuclear Information System (INIS)

    Turner, S.

    1990-01-01

    The third version of the CERN Accelerator School's (CAS) advanced course on General Accelerator Physics was given at Uppsala University from 18-29 September, 1989. Its syllabus was based on the previous courses held in Oxford, 1985 and Berlin, 1987 whose proceedings were published as CERN Yellow Reports 87-03 and 89-01 respectively. However, the opportunity was taken to emphasize the physics of small accelerators and storage rings, to present some topics in new ways, and to introduce new seminars. Thus the lectures contained in the present volume include chromaticity, dynamic aperture, kinetic theory, Landau damping, ion-trapping, Schottky noise, laser cooling and small ring lattice problems while the seminars include interpretation of numerical tracking, internal targets and living with radiation. (orig.)

  16. Does altered fractionation influence the risk of radiation-induced optic neuropathy?

    International Nuclear Information System (INIS)

    Bhandare, Niranjan; Monroe, Alan T.; Morris, Christopher G.; Bhatti, M. Tariq; Mendenhall, William M.

    2005-01-01

    Purpose: To analyze the parameters that influence the risk of radiation-induced optic neuropathy (RION) after radiotherapy for head-and-neck tumors. Methods and Materials: Between 1964 and 2000, 273 patients with tumors of the nasopharynx, paranasal sinuses, nasal cavity, and hard palate adenoid cystic carcinomas were treated with curative intent and had radiation fields that included the optic nerves and/or chiasm. Patients were followed for at least 1 year after radiotherapy. Results: Radiation-induced optic neuropathy developed in 32 eyes of 24 patients (9%). The 5-year rates of freedom from RION according to the total dose and once- vs. twice-daily fractionation were as follows: ≤63 Gy once daily, 95%; ≤63 Gy twice daily, 98%; >63 Gy once daily, 78%; and >63 Gy twice daily, 91%. Multivariate analysis revealed that the total dose affected the risk of RION (p = 0.0047), with patient age (p = 0.0909), once-daily vs. twice-daily fractionation (p = 0.0684), and overall treatment time (p = 0.0972) were marginally significant. The use of adjuvant chemotherapy did not significantly influence the likelihood of developing RION. Conclusion: The likelihood of developing RION is primarily influenced by the total dose. Hyperfractionation may reduce the risk of experiencing this complication

  17. From accelerators to storage rings to

    International Nuclear Information System (INIS)

    Panofsky, W.K.H.

    1983-02-01

    This talk gives a general but highly subjective overview of the expectation for accelerators and colliders for high energy physics, but not extended developments of accelerators and storage rings for application to nuclear structure physics, synchrotron radiation, medical applications or industrial use

  18. Spontaneous excitation of a circularly accelerated atom coupled to electromagnetic vacuum fluctuations

    International Nuclear Information System (INIS)

    Jin, Yao; Hu, Jiawei; Yu, Hongwei

    2014-01-01

    We study, using the formalism proposed by Dalibard, Dupont-Roc and Cohen-Tannoudji, the contributions of the vacuum fluctuation and radiation reaction to the rate of change of the mean atomic energy for a circularly accelerated multilevel atom coupled to vacuum electromagnetic fields in the ultrarelativistic limit. We find that the balance between vacuum fluctuation and radiation reaction is broken, which causes spontaneous excitations of accelerated ground state atoms in vacuum. Unlike for a circularly accelerated atom coupled to vacuum scalar fields, the contribution of radiation reaction is also affected by acceleration, and this term takes the same form as that of a linearly accelerated atom coupled to vacuum electromagnetic fields. For the contribution of vacuum fluctuations, we find that in contrast to the linear acceleration case, terms proportional to the Planckian factor are replaced by those proportional to a non-Planck exponential term, and this indicates that the radiation perceived by a circularly orbiting observer is no longer thermal as is in the linear acceleration case. However, for an ensemble of two-level atoms, an effective temperature can be defined in terms of the atomic transition rates, which is found to be dependent on the transition frequency of the atom. Specifically, we calculate the effective temperature as a function of the transition frequency and find that in contrast to the case of circularly accelerated atoms coupled to the scalar field, the effective temperature in the current case is always larger than the Unruh temperature. -- Highlights: •We study the spontaneous excitation of a circularly accelerated atom. •Contribution of radiation reaction to the excitation is affected by acceleration. •The radiation perceived by a circularly orbiting observer is no longer thermal. •An effective temperature can be defined in terms of atomic transition rates. •Effective temperature is larger than Unruh temperature and frequency-dependent

  19. Hadron accelerators in medicine

    International Nuclear Information System (INIS)

    Amaldi, U.

    1996-01-01

    The application of hadron accelerators (protons and light ions) in cancer therapy is discussed. After a brief introduction on the rationale for the use of heavy charged particles in radiation therapy, a discussion is given on accelerator technology and beam delivery systems. Next, existing and planned facilities are briefly reviewed. The Italian Hadron-therapy Project is then described in some detail, with reference ro both the National Centre for Oncological Hadron-therapy and the design of different types of compact proton accelerators aimed at introducing proton therapy in a large umber of hospitals. (author)

  20. High-energy inverse free-electron laser accelerator

    International Nuclear Information System (INIS)

    Courant, E.D.; Pellegrini, C.; Zakowicz, W.

    1985-01-01

    We study the inverse free electron laser (IFEL) accelerator and show that it can accelerate electrons to the few hundred GeV region with average acceleration rates of the order of 200 meV/m. Several possible accelerating structures are analyzed, and the effect of synchrotron radiation losses is studied. The longitudinal phase stability of accelerated particles is also analyzed. A Hamiltonian description, which takes into account the dissipative features of the IFEL accelerator, is introduced to study perturbations from the resonant acceleration. Adiabatic invariants are obtained and used to estimate the change of the electron phase space density during the acceleration process