Transverse colon conduit urinary diversion in patients treated with very high dose pelvic irradiation

International Nuclear Information System (INIS)

Ravi, R.; Dewan, A.K.; Pandey, K.K.

1994-01-01

Urinary diversion may be required in patients receiving pelvic irradiation for gynaecological or genitourinary cancers either as part of a planned or salvage surgical procedure or for urological complications of irradiation. Records were reviewed for 30 such patients who underwent transverse colon conduit as a primary form of urinary diversion. Most of the conduits were constructed using refluxing ureterocolic anastomoses with stents. The results showed no operative mortality. Although the procedure was associated with a complication rate of 37% and a re-operation rate of 20%, there were no bowel or urinary anastomotic leaks. The operation could be safely performed on patients with renal failure, with 83% of such patients showing normal or improved serum creatinine levels post operatively. The advantages of transverse colon conduit urinary diversion are the use of non-irradiated bowel and ureters for diversion. It is recommended as a primary form of urinary diversion in these high risk cases. (Author)

Bone marrow transplantation for girls with aplastic anemia utilizing modified field of total lymphoid irradiation and cyclophosphamide; With emphasis on the field of pelvic cavity

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Hanada, Ryoji; Kawakami, Tetsuo; Akuta, Naoko; Moriwaki, Kohichi; Kato, Shizue; Inaba, Toshiya; Hayashi, Yasuhide; Yamamoto, Keiko (Saitama Children' s Medical Center, Saitama (Japan))

1990-12-01

A preparative regimen for allogeneic bone marrow transplantation, consisting of total lymphoid irradiation (TLI) with 750 cGy and cyclophosphamide (CY), was used in five girls with aplastic anemia. All patients received bone marrow from HLA matched/mixed lymphocyte culture negative siblings. In our regimen the 'inverted Y' field to irradiate the pelvic nodes was modified, which did not include the whole pelvic cavity in an attempt to protect the ovaries from irradiation. Although some of the pelvic nodes was supported not to be irradiated in order to protect the ovaries, engraftment occurred in all five patients including four who had been transfused prior to transplantation. All five are alive from 47 days to 1378 days (median 285 days) after transplantation without tranplantation-associated complications. The calculated dose to the ovaries was sixteen percent of the entire dose of the regimen. Both of the two evaluable patients that had received tranplantation just before or during the puberty are developing normal sex maturity including menstruation. This study suggests that our preparative regimen is effective not only for engraftment of the donor marrow but also for protecting the ovaries from irradiation. (author).

The 3-Dimensional Analysis of the Efficacy of a Belly-Board Device for the Displacement of Small Bowel During Pelvic Irradiation

International Nuclear Information System (INIS)

Lee, Kyung Ja

2008-01-01

To evaluate the efficacy of a belly-board device (BBD) in reducing the volume of small bowel during four-field pelvic irradiation. Materials and Methods: Twenty-two cancer patients (14 uterine cervical cancer, 6 rectal cancer, and 2 endometrial cancer) scheduled to receive pelvic irradiation were selected for this study. Two sets of CT images were taken with and without the belly-board device using the Siemens 16 channel CT scanner. All patients were set in the prone position. The CT images were transferred to a treatment planning system for dose calculation and volume measurements. The external surfaces of small bowel and the bladder were contoured on all CT scans and the 4-pelvic fields were added. The dose-volume-histogram of the bladder and small bowel, with and without the BBD, were plotted and analyzed. Results: In all patients, the total small bowel volume included in the irradiated fields was reduced when the BBD was used. The mean volume reduction was 35% (range, 1-79%) and was statistically significant (p<0.001). The reduction in small bowel volume receiving 10-100% of the prescribed dose was statistically significant when the BBD was used in all cases. Almost no change in the total bladder volume involved was observed in the field (<8 cc, p=0.762). However, the bladder volume receiving 90% of the prescribed dose was 100% in 15/22 patients (68%) and 90-99% in 7/22 patients (32%) with the BBD. In comparison, the bladder volume receiving 90% of the prescribed dose was 100% in 10/22 patients (45%), 90-99% in 7/22 patients (32%), and 80-89% in 5/22 patients (23%) without the BBD. When the BBD was used, an increase in the bladder volume receiving a high dose range was observed Conclusion: This study shows that the use of a BBD for the treatment of cancer in the pelvic area significantly improves small bowel sparing. However, since the BBD pushed the bladder into the treatment field, the bladder volume receiving the high dose could increase. Therefore it is

Ovarian function following pelvic irradiation in prepubertal and pubertal girls and young adult women

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Schuck, A.; Hamelmann, V. [University Hospital Muenster (Germany). Dept. of Radiotherapy; Braemswig, J.H. [University Hospital Muenster (DE). Dept. of Pediatrics] [and others

2005-08-01

Purpose: To analyze the effect of pelvic radiotherapy on ovarian function in prepubertal and pubertal girls and young adult women. Patients and methods: In a retrospective monoinstitutional analysis, patients <30 years of age at diagnosis were included who had been irradiated between 1979 and 1998. The main tumor types were Hodgkin's disease (38%), Erwing's sarcoma (20%) and nephroblastoma (11%). Patients were classified into three groups according to the position of the ovary in relation to the radiation portals. Group 1 was defined by direct irradiation of both ovaries. Group 2 patients were included with both ovaries potentially located in the radiation portals. In group 3, at least one ovary was not directly irradiated. The median follow-up was 128 months. Results: 16 of 55 analyzed patients were categorized in group 1. In ten of these patients, hormone status was evaluable. The ovarian doses were {>=}15 Gy. Except for one patient treated with 15 Gy all developed hormone failure. Eight of 14 patients of group 2 were evaluable. Seven of these patients developed ovarian failure. 19 of 24 patients in group 3 were evaluable. Nine of these patients developed ovarian failure. The observed difference in the rate of ovarian failure between the groups is statistifcally significant (p=0.045). Conclusion: All patients receiving >15 Gy to the ovaries developed hormone failure. In one case of a patient receiving an ovarian dose of 15 Gy, hormone failure was not found. In case of pelvic irradiation excluding at least one ovary, approximately half of the patients developed ovarian dysfunction, probably also due to the effects of polychemotherapy. (orig.)

Stricture of the sigmoid colon after pelvic irradiation. Report of two cases

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Koga, Yutaka; Nakamura, Katsuya; Tasaki, Akira; Tsutsumi, Nobuo; Terasaka, Reiji [Shin Kokura Hospital, Kitakyushu, Fukuoka (Japan); Taguchi, Kenichi [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences

2002-07-01

Disorders of the large and small intestines after pelvic irradiation are classified into early and late complications. Common late complications are stricture and perforation. Some cases with such complications are indicated for surgical therapy. Moreover, it is suggested that radiation induced cancer can occur in patients surviving more than 5 years after radiotherapy. Patient 1, a 78-year-old woman, had been treated by surgery and pelvic irradiation for uterine cancer 20 years earlier. She had been suffered from constipation for a long time after the treatment. This time, examinations revealed a whole- circumference stricture and cancer of the sigmoid colon. Sigmoidectomy was performed. Pathological diagnosis was carcinoma in radiation colitis. Patient 2, a 73-year-old woman, had been treated by surgery and pelvic irradiation for uterine cancer 15 years earlier. This time, she admitted to the hospital because of intestinal bleeding. Angiography showed hemorrhage in the ileum. Arterial injection of vasopressin succeeded in hemostasis. However, the procedure caused marked stricture of the sigmoid colon unexpectedly. A sigmoidectomy and a partial resection of the ileum were performed. Pathological diagnosis was radiation colitis and ileitis without malignant findings. Patients with long interval after pelvic irradiation must be carefully followed from the standpoint of late complications and cancer. (author)

Late development of colorectal cancer subsequent to pelvic irradiation

International Nuclear Information System (INIS)

O'Connor, T.W.; Rombeau, J.L.; Levine, H.S.; Turnbull, R.B. Jr.

1979-01-01

Two cases of irradiation-associated carcinoma of the colon are reported and the literature reviewed. The clinical courses and operative difficulties in treating these patients are emphasized. The necessity for life-long follow-up examinations with proctoscopic and barium-enema evaluations in high-risk patients is stressed. Irradiation-associated carcinoma of the colon occurs almost exclusively in women, but should be investigated in patients of either sex who live for long periods after pelvic irradiation

Endometrial cancers occurring 10 or more years after pelvic irradiation for carcinoma

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Rodriguez, J.; Hart, W.R.

1982-01-01

Fifteen patients who developed cancer of the endometrium 10 or more years after pelvic irradiation for carcinoma were selected for study from a group of 64 cases of postirradiation malignant pelvic tumors diagnosed during a 48-year span. The average interval between radiotherapy and diagnosis of the subsequent endometrial cancer was 17.2 years. Irradiation initially had been done for squamous cell carcinoma of the cervix in 13 cases (87%) and for ovarian tumors in two instances. Almost all patients had received megavoltage external radiation combined with radium implants. Two-thirds of the tumors were adenocarcinomas and one-third were carcinosarcomas (either homologous or heterologous). Although the risk of second primary malignant tumors following therapeutic irradiation for pelvic tumors probably is very low, the emergence of new genital tract cancers in long-term survivors must be anticipated, regardless of whether the postirradiation cancers are spontaneous or radiation-induced

Effect of pelvic irradiation of lactose absorption

International Nuclear Information System (INIS)

Stryker, J.A.; Mortel, R.; Hepner, G.W.

1978-01-01

Twenty-four patients undergoing pelvic irradiation for gynecologic malignancies had 14 C-lactose breath tests performed in the first and fifth weeks of their treatment. The 14 C-lactose breath test was performed by administering 2 μCi of 14 C-lactose by mouth along with 50 g of lactose. Breath samples were collected in ethanolic hyamine 1, 2, and 3 hr later; the radioactivity of the trapped 14 CO 2 was determined by liquid scintillation spectroscopy. In the first week of treatment the percentage of administered 14 C excreted as 14 CO 2 at 1, 2, and 3 hr was 1.7 +- 0.8% (mean +- SD), 4.5 +- 1.6%, and 5.8 +- 1.4%, respectively. In the fifth week of treatment the 1-hr, 2-hr, and 3-hr values were 1.2 +- 0.9%, 3.6 +- 2.0%, and 4.7 +- 1.9%, respectively. The difference between the first week and fifth week test results at 1, 2, and 3 hr was statistically significant (t = 2.64, p 14 C-lactose breath test results in the fifth week and the stool frequency at that time (r = -0.44, p 14 C-lactose breath test results in the fifth week were below normal (<1.2%) had nausea at that time. The data suggest that in some patients, lactose malabsorption as a result of the effect of radiation on small intestinal function may be etiologically related to the symptoms of nausea and diarrhea which occur commonly in patients who are undergoing pelvic irradiation. In addition, the results suggest that lactose-containing foods should be restricted in some patients who are undergoing pelvic irradiation to prevent symptoms resulting from radiation-induced lactose intolerance

Impact of Scattered Radiation onTestosterone Deficiency and MaleHypogonadism in Rectal Cancer Treatedwith External Beam Pelvic Irradiation

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Halimeh Khatoon Ahmadi

2010-07-01

Full Text Available Background: We performed a prospective study to evaluate the effects of pelvic irradiation on FSH, LH and testosterone levels in male patients with rectal adenocarcinoma. Our aim was to compare the level of male sex hormones in peripheral blood serum before and after pelvic irradiation.Methods:The eligible participants were 40 men with rectal adenocarcinoma who underwent pelvic radiotherapy as part of their treatment for primary tumor, either beforeor after surgery. All patients received a 50-Gy radiation dose to the pelvis, 2 Gy perfraction, five days per week. Blood was sampled three times during the study: once before radiation, at the end of the radiation course and 4 to 6 weeks after radiotherapy.Results:Median age of the patients was 58 years (range 18-82. The mean testis dose of radiation per fraction in all 40 patients was 16.3 cGy with a standard deviation of 15.22 (range 5.5-64.8. Serum levels of FSH revealed a significant increase from 7.5 ± 1.7 IU/L(before treatment to 20.9 ± 17.8 IU/L[end of radiotherapy (P<0.001]and 24.1 ± 20.5 IU/L[4 to 6 weeks after radiotherapy (P<0.001]. Serum LH levelswere significantly elevated from 8.04 ± 1.2 IU/L before radiation to 11.6 ± 11.5 IU/Lat the end of radiotherapy (P<0.001 and 12.5 ± 9.9 IU/L4 to 6 weeks after the final course of radiotherapy (P<0.001. There was a decrease in serum testosterone from5.3±2.1 ng/mL before radiation to 4.2 ± 1.9 ng/mLat the end of radiotherapy (P=0.004and 4.5 ± 2 ng/mL4 to 6 weeks after radiotherapy (P=0.035. No significant correlation was seen between age and differences in sex hormones (LH, P=0.605; FSH, P=0.380;testosterone,P=0.161.Conclusion:There was a significant change in serum levels of male sex hormones after pelvic irradiation for rectal cancer (total dose, 50 Gy that indicates considerable testicular damage under these circumstances. Thus, it seems logical to use techniques that reduce the radiation dose to the testicles and to consider the

Ovarian carcinoma: improved survival following abdominopelvic irradiation in patients with a completed pelvic operation

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Dembo, A.J.; Bush, R.S.; Beale, F.A.; Bean, H.A.; Pringle, J.F.; Sturgeon, J.; Reid, J.G.

1979-01-01

A prospective, stratified, randomized study of 190 postoperative ovarian carcinoma patients with Stages IB, II, and III (asymptomatic) presentations is reported. The median time of follow-up was 52 months. Patients in whom bilateral salpingo-oophorectomy and hysterectomy (BSOH) could not be completed because of extensive pelvic tumor had a poor prognosis which did not differ for any of the therapies tested. When BSOH was completed, pelvic plus abdominopelvic irradiation (P + AB) with no diaphragmatic shielding significantly improved patient survival rate and long-term control of occult upper abdominal disease in approximately 25% more patients than pelvic irradiation alone or followed by adjuvant daily chlorambucil therapy. The effectiveness of P + AB in BSOH-completed patients was independent of stage or tumor grade and was most clearly appreciated in patients with all gross tumor removed. Chlorambucil added to pelvic irradiation delayed the time to treatment failure without reducing the number of treatment failures

SU-F-T-437: 3 Field VMAT Technique for Irradiation of Large Pelvic Tumors

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Stakhursky, V [Radiation Oncology, Norwalk Hospital, Norwalk, CT (United States)

2016-06-15

Purpose: VMAT treatment planning for large pelvic volume irradiation could be suboptimal due to inability of Varian linac to split MLC carriage during VMAT delivery for fields larger than 14.5cm in X direction (direction of leaf motion). We compare the dosimetry between 3 VMAT planning techniques, two 2-arc field techniques and a 3-arc field technique: a) two small in X direction (less than 14.5cm) arc fields, complementing each other to cover the whole lateral extent of target during gantry rotation, b) two large arc fields, each covering the targets completely during the rotation, c) a 3 field technique with 2 small in X direction arcs and 1 large field covering whole target. Methods: 5 GYN cancer patients were selected to evaluate the 3 VMAT planning techniques. Treatment plans were generated using Varian Eclipse (ver. 11) TPS. Dose painting technique was used to deliver 5300 cGy to primary target and 4500 cGy to pelvic/abdominal node target. All the plans were normalized so that the prescription dose of 5300 cGy covered 95% of primary target volume. PTV and critical structures DVH curves were compared to evaluate all 3 planning techniques. Results: The dosimetric differences between the two 2-arc techniques were minor. The small field 2-arc technique showed a colder hot spot (0.4% averaged), while variations in maximum doses to critical structures were statistically nonsignificant (under 1.3%). In comparison, the 3-field technique demonstrated a colder hot spot (1.1% less, 105.8% averaged), and better sparing of critical structures. The maximum doses to larger bowel, small bowel and gluteal fold were 3% less, cord/cauda sparing was 4.2% better, and bladder maximum dose was 4.6% less. The differences in maximum doses to stomach and rectum were statistically nonsignificant. Conclusion: 3-arc VMAT technique for large field irradiation of pelvis demonstrates dosimetric advantages compared to 2-arc VMAT techniques.

Post Pelvic Radiotherapy Bony Changes

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Huh, Seung Jae [Samsung Medical Center, Seoul (Korea, Republic of)

2009-03-15

There has been recent interest in radiation-induced bone injury in clinical conditions, especially for pelvic insufficiency fracture (PIF). A PIF is caused by the effect of normal or physiological stress on bone with demineralization and decreased elastic resistance. Pelvic radiotherapy (RT) can also contribute to the development of a PIF. A PIF has been regarded as a rare complication with the use of megavoltage equipment. However, recent studies have reported the incidence of PIFs as 8.2{approx}20% after pelvic RT in gynecological patients, an incidence that was higher than previously believed. The importance of understanding a PIF lies in the potential for misdiagnosis as a bony metastasis. If patients complain of pelvic pain after whole-pelvis radiation therapy, the presence of a PIF must be considered in the differential diagnosis. The use of multibeam arrangements and conformal RT to reduce the volume and dose of irradiated pelvic bone can be helpful to minimize the risk of fracture. In addition to a PIF, osteonecrosis and avascular necrosis of the femoral head can develop after radiation therapy. Osteoradionecrosis of the pelvic bone is a clinical diagnostic challenge that must be differentiated from an osseous metastasis. A post-radiation bone sarcoma can result as a long-term sequela of pelvic irradiation for uterine cervical cancer.

The irradiation tolerance dose of the proximal vagina

International Nuclear Information System (INIS)

Au, Samuel P.; Grigsby, Perry W.

2003-01-01

Purpose: The purpose of this investigation was to determine the irradiation tolerance level and complication rates of the proximal vagina to combined external irradiation and low dose rate (LDR) brachytherapy. Also, the mucosal tolerance for fractionated high dose rate (HDR) brachytherapy is further projected based on the biological equivalent dose (BED) of LDR for an acceptable complication rate. Materials and methods: Two hundred seventy-four patients with stages I-IV cervical carcinoma treated with irradiation therapy alone from 1987 to 1997 were retrospectively reviewed for radiation-associated late sequelae of the proximal vagina. All patients received LDR brachytherapy and 95% also received external pelvic irradiation. Follow-up ranged from 15 to 126 months (median, 43 months). The proximal vagina mucosa dose from a single ovoid (single source) or from both ovoids plus the tandem (all sources), together with the external irradiation dose, were used to derive the probability of a complication using the maximum likelihood logistic regression technique. The BED based on the linear-quadratic model was used to compute the corresponding tolerance levels for LDR or HDR brachytherapy. Results: Grades 1 and 2 complications occurred in 10.6% of patients and Grade 3 complications occurred in 3.6%. There were no Grade 4 complications. Complications occurred from 3 to 71 months (median, 7 months) after completion of irradiation, with over 60% occurring in the first year. By logistic regression analysis, both the mucosal dose from a single ovoid or that from all sources, combined with the external irradiation dose, demonstrate a statistically significant fit to the dose response complication curves (both with P=0.016). The single source dose was highly correlated with the all source dose with a cross-correlation coefficient 0.93. The all source dose was approximately 1.4 times the single source dose. Over the LDR brachytherapy dose rate range, the complication rate was

Evaluation of the anode heel effect on the testes dose during pelvic radiography

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Vahid Karami

2017-05-01

Full Text Available Background: Anode heel effect refers to reduction of radiation intensity in the anode side of X-ray tube. This variation in radiation intensity across the anode-cathode of X-ray tube can be benefited for decrease radiation exposure in some radiological examinations. The aim of this study was to evaluate the effect of anode heel orientation on the radiation dose received by the testes in male patients undergoing pelvic radiography. Methods: This is a cross-sectional study, conducted at one of the teaching hospitals of Ahvaz, Jundishapur University of Medical Science Ahvaz, Iran, from September 2015 to March 2016. In order to measure the profile of radiation intensity variation, 13 paired sets of high radiosensitive cylindrical lithium fluoride thermo-luminescent dosimeters (TLD aligned on the cathode-anode central axis upon the table and then irradiated using routine exposure parameters. The anode of X-ray tube was positioned toward the feet for 40 patients and toward the head for 39 patients undergoing pelvic radiography. For measure the entrance skin dose (ESD, 8 TLD chips were located on the central point of the radiation field and 5 TLDs were located on the testes position to measure the dose received. Results: Radiation intensity profile showed that radiation intensity decrease from the cathode to the anode side. Discrepancy of radiation intensity on central axis of cathode-anode was calculated about 35%. The radiation dose received by the testes was 26.74% lower for patients the anode directed toward the feet, compared to the patients in which the anode directed toward the head (FTC: 1.260±0.296 mGy, FTA: 0.923±0.167 mGy, P<0.05. There was no meaningful difference for the measured ESD of pelvis between two groups of patients (FTC: 1.256±0.315 mGy, FTA: 1.195±0.205 mGy, P=0.788. Conclusion: In pelvic radiography, positioning of testes directed to the anode of X-ray tube can decrease the receive dose.

Clinical outcome of extended-field irradiation vs. pelvic irradiation using intensity-modulated radiotherapy for cervical cancer.

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Ouyang, Yi; Wang, Yanhong; Chen, Kai; Cao, Xinping; Zeng, Yiming

2017-12-01

The aim of the present study was to evaluate the distinctions in survival and toxicity between patients with cervical cancer with common iliac node or para-aortic node involvement, who were treated with extended-field intensity-modulated radiotherapy (EF-IMRT) and patients with or without lower involved pelvic nodes, who were treated with pelvic IMRT. A total of 55 patients treated with EF-IMRT and 52 patients treated with pelvic IMRT at the Sun Yat-Sen University Cancer Center (Guangzhou, China) were retrospectively analyzed. Patients treated with EF-IMRT had the highest level of lymph node involvement to the para-aortic or common iliac nodes, while patients treated with pelvic IMRT had no para-aortic or common iliac nodes involved (Pirradiation was a protective prognostic factor for OS and DFS. A total of 16 patients in the EF-IMRT group and 13 patients in the pelvic IMRT group experienced treatment failure (P=0.67), with the patterns of failure being the same for the two groups (P=0.88). The cumulative incidence of grade 3 and 4 acute toxicities in the EF-IMRT group was 34.5%, in comparison with 19.2% in the pelvic group (P=0.048). The results of the present study suggest that patients with cervical cancer with grossly involved common iliac or para-aortic nodes should be electively subjected to EF irradiation to improve the survival and alter patterns of recurrence. Notably, EF irradiation delivered via IMRT exhibits an increased toxicity incidence, however, this remains within an acceptable range.

Pelvic Insufficiency Fracture After Pelvic Radiotherapy for Cervical Cancer: Analysis of Risk Factors

International Nuclear Information System (INIS)

Oh, Dongryul; Huh, Seung Jae; Nam, Heerim; Park, Won; Han, Youngyih; Lim, Do Hoon; Ahn, Yong Chan; Lee, Jeong Won; Kim, Byoung Gie; Bae, Duk Soo; Lee, Je Ho

2008-01-01

Purpose: To investigate the incidence, clinical characteristics, and risk factors of pelvic insufficiency fracture (PIF) after pelvic radiotherapy (RT) in cervical cancer. Methods and Materials: Medical records and imaging studies, including bone scintigraphy, CT, and MRI of 557 patients with cervical cancer who received whole-pelvic RT between January 1998 and August 2005 were reviewed. Results: Eighty-three patients were diagnosed as having PIF after pelvic RT. The 5-year cumulative incidence of PIF was 19.7%. The most commonly involved site was the sacroiliac joint. Pelvic pain developed in 48 patients (57.8%) at diagnosis. Eleven patients (13.3%) needed admission or narcotics because of severe pain, and others had good relief of symptoms with conservative management. In univariate analysis, age ≥55 years (p < 0.001), anteroposterior/posteroanterior parallel opposing technique (p = 0.001), curative treatment (p < 0.001), and radiation dose ≥50.4 Gy (p = 0.005) were the predisposing factors for development of PIF. Concurrent chemotherapy (p = 0.78) was not significant. Multivariate analysis showed that age ≥55 years (p < 0.001), body weight <55 kg (p = 0.02), curative treatment (p = 0.03), and radiation dose ≥50.4 Gy (p = 0.04) were significant predisposing factors for development of PIF. Conclusion: The development of PIF is not rare after pelvic RT. The use of multibeam arrangements to reduce the volume and dose of irradiated pelvic bone can be helpful to minimize the risk of fracture, especially in elderly women with low body weight

Postoperative low-pelvic irradiation for stage I-IIA cervical cancer patients with risk factors other than pelvic lymph node metastasis

International Nuclear Information System (INIS)

Hong, J.-H.; Tsai, C.-S.; Lai, C.-H.; Chang, T.-C.; Wang, C.-C.; Lee, Steve P.; Tseng, C.-J.; Hsueh, Swei

2002-01-01

Purpose: To retrospectively investigate whether postoperative low-pelvic radiotherapy (RT) is an appropriate treatment for node-negative, high-risk Stage I-IIA cervical cancer patients. Methods and Materials: A total of 228 Stage I-IIA cervical cancer patients treated by radical surgery and postoperative RT were included in this study. All patients had histopathologically negative pelvic node metastasis, but at least one of the following risk factors: parametrial involvement, positive or close resection margins, invasion depth two-thirds or greater cervical stromal thickness. Seventy-nine patients (35%) received 30-50 Gy (median 44) to whole pelvis and a boost dose to the low pelvis (whole-pelvic RT group); the other 149 patients (65%) received low-pelvic RT only (low-pelvic RT group). For both groups, the total external RT dose to the low pelvis ranged from 40 to 60 Gy (median 50). The potential factors associated with survival, small bowel (gastrointestinal) complications, and leg lymphedema were analyzed, and patients who had a relapse in the upper pelvis were identified. Results: The 5-year overall and disease-specific survival rate was 84% and 86%, respectively. After multivariate analysis, only bulky tumor (≥4 cm) and non-squamous cell carcinoma were significantly associated with survival. Parametrial involvement, lymph-vascular invasion, ≤50.4 Gy to the low pelvis, positive or close margins, and low-pelvic RT alone did not significantly affect survival. Grade I-V small bowel complications occurred in 33 patients (15%). Whole pelvic RT and >50.4 Gy to the low pelvis, but not old age and treatment technique (AP-PA vs. box), were significantly associated with gastrointestinal complications. Three patients (2%) in the low-pelvic RT group and 6 patients (8%) in the whole-pelvic RT group were found to have Grade III or higher small bowel complications (p=0.023). Thirty-one percent of patients developed lymphedema of the leg. A dose to the low pelvis >50.4 Gy

Impact of hip prosthesis on dose distribution of pelvic radiotherapy

International Nuclear Information System (INIS)

Ren Jiangping; Zhang Songfang; Zhu Qibao; Guo Jianxin; Zha Yuanzi

2011-01-01

Objective: To study the scattering effect of Co-Cr-Mo hip prosthesis which was high Z material for patients undergoing pelvic irradiation. Methods: The hip prosthesis was set in water phantom (30 cm x 30 cm x 30 cm), determining points were chosen on the entrance side of both 6 MV and 10 MV beams at the distance of 0.5 cm, 1.0 cm, 2.0 cm to the hip prosthesis, and also on the exit side of both 6 MV and 10 MV beams at the distance of 3.0 cm, 5.0 cm, 7.0 cm to the hip prostheses. Dose behind the hip prosthesis at depths of 5.0 cm and 10.0 cm for 6 MV and 10 MV beams are also measured. Results: The dose deviation on the beams' entrance side is between 0 to 5.0%, the backscatter effect was more obviously with the higher energy beam. The dose deviation on the beams' exit side was between 21.6%-30.8%. With the same field size and depth, dose deviation becomes smaller when the beam energy was higher; while with the same energy and depth, dose deviation becomes smaller when the field size was bigger. Dose profiles behind the head of the hip prosthesis indicate obvious attenuation of the beam. Conclusions: Beam arrangements that avoid the prosthesis should be considered first or we should at least reduce the weight of the beam that pass through the prosthesis. (authors)

Post-irradiation diarrhea

International Nuclear Information System (INIS)

Meerwaldt, J.H.

1984-01-01

In radiotherapy of pelvic cancers, the X-ray dose to be delivered to the tumour is limited by the tolerance of healthy surrounding tissue. In recent years, a number of serious complications of irradiation of pelvic organs were encountered. Modern radiotherapy necessitates the acceptance of a calculated risk of complications in order to achieve a better cure rate. To calculate these risks, one has to know the radiation dose-effect relationship of normal tissues. Of the normal tissues most at risk when treating pelvic tumours only the bowel is studied. In the literature regarding post-irradiation bowel complications, severe and mild complications are often mixed. In the present investigation the author concentrated on the group of patients with relatively mild symptoms. He studied the incidence and course of post-irradiation diarrhea in 196 patients treated for carcinoma of the uterine cervix or endometrium. The aims of the present study were: 1) to determine the incidence, course and prognostic significance of post-irradiation diarrhea; 2) to assess the influence of radiotherapy factors; 3) to study the relation of bile acid metabolism to post-irradiation diarrhea; 4) to investigate whether local factors (reservoir function) were primarily responsible. (Auth.)

Dose Distribution of Rectum and Bladder in Intracavitary Irradiation

International Nuclear Information System (INIS)

Chu, S. S.; Oh, W. Y.; Suh, C. O.; Kim, G. E.

1984-01-01

The intrauterine irradiation is essential to achieve adequate tumor dose to central tumor mass of uterine malignancy in radiotherapy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The simulation radiogram and medical records of 206 patients, who were treated with intrauterine irradiation from Feb. 1983 to Oct. 1983, were critically analyzed. The physical parameters to include distances between lateral walls of vaginal fornices, longitudinal and lateral cervix to the central axis of ovoid were measured for low dose rate irradiation system and high dose rate remote control after loading system. The radiation doses and dose distributions within cervical area including interesting points and bladder, rectum, according to sources arrangement and location of applicator, were estimated with personal computer. Followings were summary of study results; 1. In distances between lateral walls of vaginal fornices, the low dose rate system showed as 4-7cm width and high dose rate system showed as 5-6cm. 2. In Horizontal angulation of tandem to body axis, the low dose rate system revealed mid position 64.6%, left deviation 19.2% and right deviation 16.2%. 3. In longitudinal angulation of tandem to body axis, the mid position was 11.8% and anterior angulation 88.2% in low dose rate system but in high dose rate system, anterior angulation was 98.5%. 4. Down ward displacement of ovoid below external os was only 3% in low dose rate system and 66.6% in high dose rate system. 5. In radiation source arrangement, the most activities of tandem and ovoid were 35 by 30 in low dose rate system but 50 by 40 in high dose rate system. 6. In low and high dose rate system, the total doses and TDF were 80, 70 Gy and 131, 123 including 40 Gy external irradiation. 7. The doses and TDF in interesting points Co, B, were 98, 47 Gy and 230, 73 in high dose rate system but in low dose rate system 125, 52 Gy and 262, 75 respectively. 8. Doses

Dose-Effect Relationships for Individual Pelvic Floor Muscles and Anorectal Complaints After Prostate Radiotherapy

International Nuclear Information System (INIS)

Smeenk, Robert Jan; Hoffmann, Aswin L.; Hopman, Wim P.M.; Lin, Emile N.J. Th. van; Kaanders, Johannes H.A.M.

2012-01-01

Purpose: To delineate the individual pelvic floor muscles considered to be involved in anorectal toxicity and to investigate dose-effect relationships for fecal incontinence-related complaints after prostate radiotherapy (RT). Methods and Materials: In 48 patients treated for localized prostate cancer, the internal anal sphincter (IAS) muscle, the external anal sphincter (EAS) muscle, the puborectalis muscle (PRM), and the levator ani muscles (LAM) in addition to the anal wall (Awall) and rectal wall (Rwall) were retrospectively delineated on planning computed tomography scans. Dose parameters were obtained and compared between patients with and without fecal urgency, incontinence, and frequency. Dose-effect curves were constructed. Finally, the effect of an endorectal balloon, which was applied in 28 patients, was investigated. Results: The total volume of the pelvic floor muscles together was about three times that of the Awall. The PRM was exposed to the highest RT dose, whereas the EAS received the lowest dose. Several anal and rectal dose parameters, as well as doses to all separate pelvic floor muscles, were associated with urgency, while incontinence was associated mainly with doses to the EAS and PRM. Based on the dose-effect curves, the following constraints regarding mean doses could be deduced to reduce the risk of urgency: ≤30 Gy to the IAS; ≤10 Gy to the EAS; ≤50 Gy to the PRM; and ≤40 Gy to the LAM. No dose-effect relationships for frequency were observed. Patients treated with an endorectal balloon reported significantly less urgency and incontinence, while their treatment plans showed significantly lower doses to the Awall, Rwall, and all pelvic floor muscles. Conclusions: Incontinence-related complaints show specific dose-effect relationships to individual pelvic floor muscles. Dose constraints for each muscle can be identified for RT planning. When only the Awall is delineated, substantial components of the continence apparatus are

Dose-effect relationships for individual pelvic floor muscles and anorectal complaints after prostate radiotherapy.

Science.gov (United States)

Smeenk, Robert Jan; Hoffmann, Aswin L; Hopman, Wim P M; van Lin, Emile N J Th; Kaanders, Johannes H A M

2012-06-01

To delineate the individual pelvic floor muscles considered to be involved in anorectal toxicity and to investigate dose-effect relationships for fecal incontinence-related complaints after prostate radiotherapy (RT). In 48 patients treated for localized prostate cancer, the internal anal sphincter (IAS) muscle, the external anal sphincter (EAS) muscle, the puborectalis muscle (PRM), and the levator ani muscles (LAM) in addition to the anal wall (Awall) and rectal wall (Rwall) were retrospectively delineated on planning computed tomography scans. Dose parameters were obtained and compared between patients with and without fecal urgency, incontinence, and frequency. Dose-effect curves were constructed. Finally, the effect of an endorectal balloon, which was applied in 28 patients, was investigated. The total volume of the pelvic floor muscles together was about three times that of the Awall. The PRM was exposed to the highest RT dose, whereas the EAS received the lowest dose. Several anal and rectal dose parameters, as well as doses to all separate pelvic floor muscles, were associated with urgency, while incontinence was associated mainly with doses to the EAS and PRM. Based on the dose-effect curves, the following constraints regarding mean doses could be deduced to reduce the risk of urgency: ≤ 30 Gy to the IAS; ≤ 10 Gy to the EAS; ≤ 50 Gy to the PRM; and ≤ 40 Gy to the LAM. No dose-effect relationships for frequency were observed. Patients treated with an endorectal balloon reported significantly less urgency and incontinence, while their treatment plans showed significantly lower doses to the Awall, Rwall, and all pelvic floor muscles. Incontinence-related complaints show specific dose-effect relationships to individual pelvic floor muscles. Dose constraints for each muscle can be identified for RT planning. When only the Awall is delineated, substantial components of the continence apparatus are excluded. Copyright © 2012 Elsevier Inc. All rights

Dose-volume effects for pelvic bone marrow in predicting hematological toxicity in prostate cancer radiotherapy with pelvic node irradiation.

Science.gov (United States)

Sini, Carla; Fiorino, Claudio; Perna, Lucia; Noris Chiorda, Barbara; Deantoni, Chiara Lucrezia; Bianchi, Marco; Sacco, Vincenzo; Briganti, Alberto; Montorsi, Francesco; Calandrino, Riccardo; Di Muzio, Nadia; Cozzarini, Cesare

2016-01-01

To prospectively identify clinical/dosimetric predictors of acute/late hematologic toxicity (HT) in chemo-naÏve patients treated with whole-pelvis radiotherapy (WPRT) for prostate cancer. Data of 121 patients treated with adjuvant/salvage WPRT were analyzed (static-field IMRT n=19; VMAT/Rapidarc n=57; Tomotherapy n=45). Pelvic bone marrow (BM) was delineated as ilium (IL), lumbosacral, lower and whole pelvis (WP), and the relative DVHs were calculated. HT was graded both according to CTCAE v4.03 and as variation in percentage relative to baseline. Logistic regression was used to analyze association between HT and clinical/DVHs factors. Significant differences (p<0.005) in the DVH of BM volumes between different techniques were found: Tomotherapy was associated with larger volumes receiving low doses (3-20 Gy) and smaller receiving 40-50 Gy. Lower baseline absolute values of WBC, neutrophils and lymphocytes (ALC) predicted acute/late HT (p ⩽ 0.001). Higher BM V40 was associated with higher risk of acute Grade3 (OR=1.018) or late Grade2 lymphopenia (OR=1.005). Two models predicting lymphopenia were developed, both including baseline ALC, and BM WP-V40 (AUC=0.73) and IL-V40+smoking (AUC=0.904) for acute/late respectively. Specific regions of pelvic BM predicting acute/late lymphopenia, a risk factor for viral infections, were identified. The 2-variable models including specific constraints to BM may help reduce HT. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Prospective study of irradiation and magnification on a pelvic imaging: EOS system versus conventional radiography

International Nuclear Information System (INIS)

Demoulin, Loic

2015-01-01

The pelvic x-ray is essential for the orthopedic practise. Recently, EOS system has been developed with technology to limit irradiation and theoretically not create magnification. The objective of this study was to evaluate the EOS system realizing a pelvic x-ray. All patients who underwent hip replacement between September 2014 and April 2015 have benefited pelvis radiograph with the 2 techniques, after surgery. The size of the head was measured with both techniques and compared to the established size. Irradiation of each technique was listed. A correlation study was carried out with the body mass index (BMI) of the patient. Irradiation was significantly greater with conventional radiography than with the EOS system: PDS of conventional radiography = 15.0 (10.5; 25.2) against the EOS system PDS = 8.2 (7.1; 9.7), p ≤0.0001. It was found a significant correlation between BMI and irradiation, particularly with conventional radiography. About expansion, the EOS system not create any except in 4 cases, unlike the conventional radiograph. The EOS system significantly decreases irradiation in all patients, compared to the conventional radiography, and it do not create magnification when realizing a pelvic x-ray, even in overweight patients [fr

Carcinoma of vagina 10 or more years following pelvic irradiation therapy

International Nuclear Information System (INIS)

Pride, G.L.; Buchler, D.A.

1977-01-01

Gynecologic cancer records of 4,238 patients treated between 1956 and 1974 were reviewed. Sixteen patients developed neoplasia in the cervix or vagina 10 or more years following pelvic irradiation. Three patients had squamous carcinoma in situ; the other 13 patients had invasive squamous cancer involving the upper vagina. Only 1.26 percent of invasive carcinoma of the cervix treated by radiation therapy from 1956 to 1966 presented with a late or recurrent or new primary tumor involving the vagina or cervix 10 or more years after primary treatment. The authors conclude that the risk of developing radiation-induced carcinoma in the upper vagina or cervix following pelvic irradiation is low. Follow-up Pap smears are indicated for all patients treated for cervical or vaginal malignancies by radiation therapy in order to detect vaginal neoplasia as well as recurrent carcinoma of the cervix

Effect of pelvic irradiation on the bone mineral content of lumbar spine in cervical cancer

International Nuclear Information System (INIS)

Youn, S. M.; Choi, T. J.; Koo, E. S.; Kim, O. B.; Lee, S. M.; Suh, S. J.

1997-01-01

To evaluate the loss of bone mineral contents(BMC) in lumbar spine within the radiation field for cervical cancer treatment, BMC in the irradiated patient group was compared with that of a normal control group. Measurements of BMC in the trabecular bone in lumbar spines(L3-L5) were performed in the both patient and normal control groups. Investigators used dual-energy quantitative computerized tomography(DEQCD) using photon energy of 120 and 80kVp. The numbers of patient and control groups were 43 in each with age distribution of fifth to seventh decade of women. The numbers of control group were 22 in fifth, 10 in sixth, and 11 in seventh decade, those of patient group were 14 in fifth, 14 in sixth, and 15 in seventh decade of women. The radiation field was extended to L5 spine for pelvic irradiation with 45-54Gy of external radiation dose and 30Gy of high dose rate brachytherapy in cervical cancer. The BMC is decreased as increasing age in both control and patient groups. BMC in lumbar spine of patient group was decreased by about 13% to 40% maximally. The BMC of L3 and L4 a region that is out of a radiation field for the patient group demonstrated 119.5 ±30.6, 117.0 ±31.7 for fifth, 83.3 ± 37.8, 88.3 ± 46.8 for sixth and 61.5 ± 18.3, 56.2 ± 26.6 mg/cc for seventh. Contrasted by the normal control group has shown 148.0 ± 19.9, 153.2 ± 23.2 for fifth, 96.1 ± 30.2, 105.6 ± 26.5 for sixth and 73.9 ± 27.9, 77.2 ± 27.2 mg/cc for seventh decade, respectively. The BMC of patient group was decreased as near the radiation field, while the lower lumbar spine has shown more large amounts of BMC in the normal control group. In particular, the BMC of L5 within the radiation field was significantly decreased to 33%, 31%, 40% compared with the control group of the fifth, sixth and seventh decades, respectively. The pelvic irradiation in cervical cancer has much effected on the loss of bone mineral content of lumbar spine within the radiation field, as the lower

Evaluation of the Entrance Surface Dose (ESD and Radiation Dose to the Radiosensitive Organs in Pediatric Pelvic Radiography

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Vahid Karami

2017-06-01

Full Text Available Background Patients' dosimetry is crucial in order to enhance radiation protection optimization and to deliver low radiation dose to the patients in a radiological procedure. The aim of this study was to assess the entrance surface dose (ESD and radiation dose to the radiosensitive organs in pediatric pelvic radiography. Materials and Methods The studied population included 98 pediatric patients of both genders referred to anteroposterior (AP projection of pelvic radiography. The radiation dose was directly measured using high radiosensitive cylindrical lithium fluoride thermo-luminescent dosimeters (TLD-GR200. Two TLDs were placed at the center point of the radiation field to measure the ESD of pelvis. Moreover for each patient, 2 TLDs were placed upon each eyelid, 2 TLDs upon each breast, 2 TLDs upon the surface anatomical position of the thyroid gland and finally 2 TLDs at the surface anatomical position of the gonads to measure the received dose. Results The ESD ± standard deviation for AP pelvic radiography was obtained 591.7±76 µGy. Statistically significant difference was obtained between organs located outside and inside of the radiation field with respect to dose received (P

The Different Volume Effects of Small-Bowel Toxicity During Pelvic Irradiation Between Gynecologic Patients With and Without Abdominal Surgery: A Prospective Study With Computed Tomography-Based Dosimetry

International Nuclear Information System (INIS)

Huang, E.-Y.; Sung, C.-C.; Ko, S.-F.; Wang, C.-J.; Yang, Kuender D.

2007-01-01

Purpose: To evaluate the effect of abdominal surgery on the volume effects of small-bowel toxicity during whole-pelvic irradiation in patients with gynecologic malignancies. Methods and Materials: From May 2003 through November 2006, 80 gynecologic patients without (Group I) or with (Group II) prior abdominal surgery were analyzed. We used a computed tomography (CT) planning system to measure the small-bowel volume and dosimetry. We acquired the range of small-bowel volume in 10% (V10) to 100% (V100) of dose, at 10% intervals. The onset and grade of diarrhea during whole-pelvic irradiation were recorded as small-bowel toxicity up to 39.6 Gy in 22 fractions. Results: The volume effect of Grade 2-3 diarrhea existed from V10 to V100 in Group I patients and from V60 to V100 in Group II patients on univariate analyses. The V40 of Group I and the V100 of Group II achieved most statistical significance. The mean V40 was 281 ± 27 cm 3 and 489 ± 34 cm 3 (p 3 and 132 ± 19 cm 3 (p = 0.003). Multivariate analyses revealed that V40 (p = 0.001) and V100 (p = 0.027) were independent factors for the development of Grade 2-3 diarrhea in Groups I and II, respectively. Conclusions: Gynecologic patients without and with abdominal surgery have different volume effects on small-bowel toxicity during whole-pelvic irradiation. Low-dose volume can be used as a predictive index of Grade 2 or greater diarrhea in patients without abdominal surgery. Full-dose volume is more important than low-dose volume for Grade 2 or greater diarrhea in patients with abdominal surgery

Dose-response and failure pattern for bulky or barrel-shaped stage IB cervical cancer treated by combined photon irradiation and extrafascial hysterectomy

International Nuclear Information System (INIS)

Maruyama, Y.; van Nagell, J.R.; Yoneda, J.; Donaldson, E.; Gallion, H.H.; Higgins, R.; Powell, D.; Kryscio, R.; Berner, B.

1989-01-01

From 1975 to 1987, 80 patients with bulky or barrel-shaped Stage IB cervical cancer were treated with preoperative irradiation and Cs-137 intracavitary implant therapy, before a planned extrafascial abdominal hysterectomy, using a consistent treatment policy. Of the hysterectomy specimens obtained, 37% were positive histologically at 89 +/- 2.3 days after the start of radiotherapy and at 4 to 6 weeks after the completion of radiation therapy. Sixty-three percent were negative after a total external and internal cervix irradiation dose of 9642 cGy at point T. The average point A dose contributed by intracavitary therapy was 2104 cGy. The survival rate at 5 years was 84%: At 10 years the survival rate was 78%. The failure pattern was analyzed for patients who had positive and negative specimens. The patients with positive specimens failed pelvically or pelvically and distantly. Patients with negative specimens failed in extrapelvic or distant metastatic sites. Preoperative radiotherapy led to excellent local and pelvic control of tumor, and the failures became predominantly distant metastases. The combined radiosurgical therapy was tolerated well and allowed surgical staging of disease. This permitted earlier and selective consideration of adjunctive therapy (i.e., paraaortic irradiation, chemotherapy, or chemoradiotherapy). The dose-response data give insight into the effects of photon radiotherapy on bulky or barrel Stage IB cervical cancers and correlate histologic status with failure pattern, outcome, and long-term survival

Treatment planning with protons for pediatric retinoblastoma, medulloblastoma, and pelvic sarcoma: How do protons compare with other conformal techniques?

International Nuclear Information System (INIS)

Lee, Catherine T.; Bilton, Stephen D.; Famiglietti, Robin M.; Riley, Beverly A.; Mahajan, Anita; Chang, Eric L.; Maor, Moshe H.; Woo, Shiao Y.; Cox, James D.; Smith, Alfred R.

2005-01-01

Purpose: To calculate treatment plans and compare the dose distributions and dose-volume histograms (DVHs) for photon three-dimensional conformal radiation therapy (3D-CRT), electron therapy, intensity-modulated radiation therapy (IMRT), and standard (nonintensity modulated) proton therapy in three pediatric disease sites. Methods and Materials: The tumor volumes from 8 patients (3 retinoblastomas, 2 medulloblastomas, and 3 pelvic sarcomas) were studied retrospectively to compare DVHs from proton therapy with 3D-CRT, electron therapy, and IMRT. In retinoblastoma, several planning techniques were analyzed: A single electron appositional beam was compared with a single 3D-CRT lateral beam, a 3D-CRT anterior beam paired with a lateral beam, IMRT, and protons. In medulloblastoma, three posterior fossa irradiation techniques were analyzed: 3D-CRT, IMRT, and protons. Craniospinal irradiation (which consisted of composite plans of both the posterior fossa and craniospinal components) was also evaluated, primarily comparing spinal irradiation using 3D-CRT electrons, 3D-CRT photons, and protons. Lastly, in pelvic sarcoma, 3D-CRT, IMRT, and proton plans were assessed. Results: In retinoblastoma, protons resulted in the best target coverage combined with the most orbital bone sparing (10% was the mean orbital bone volume irradiated at ≥5 Gy for protons vs. 25% for 3D-CRT electrons, 69% for IMRT, 41% for a single 3D lateral beam, 51% for a 3D anterolateral beam with a lens block, and 65% for a 3D anterolateral beam without a lens block). A single appositional electron field was the next best technique followed by other planning approaches. In medulloblastoma, for posterior fossa and craniospinal irradiation, protons resulted in the least dose to the cochlea (for only posterior fossa irradiation at ≥20 Gy, 34% was the mean cochlear volume irradiated for protons, 87% for IMRT, 89% for 3D-CRT) and hypothalamus-pituitary axis (for only posterior fossa irradiation at ≥10 Gy

Spontaneous occurrence of synergistic bacterial gangrene following external pelvic irradiation

International Nuclear Information System (INIS)

Husseinzadeh, N.; Nahhas, W.A.; Manders, E.K.; Whitney, C.W.; Mortel, R.

1984-01-01

A case of spontaneous synergistic bacterial gangrene occurring after external pelvic irradiation is presented in a 25-year-old woman with invasive cervical cancer. Treatment consisted of aggressive antibiotic therapy and extensive excision and debridement followed by split-thickness skin grafting. Both recovery and cosmetic results were satisfactory. The pathophysiology, predisposing factors, and treatment modalities are presented

Dose Distribution of Gamma Irradiators

International Nuclear Information System (INIS)

Park, Seung Woo; Shin, Sang Hun; Son, Ki Hong; Lee, Chang Yeol; Kim, Kum Bae; Jung, Hai Jo; Ji, Young Hoon

2010-01-01

Gamma irradiator using Cs-137 have been widely utilized to the irradiation of cell, blood, and animal, and the dose measurement and education. The Gamma cell 3000 Elan (Nordion International, Kanata, Ontario, Canada) irradiator was installed in 2003 with Cs-137 and dose rate of 3.2 Gy/min. And the BioBeam 8000 (Gamma-Service Medical GmbH, Leipzig, Germany) irradiator was installed in 2008 with Cs-137 and dose rate of 3.5 Gy/min. Our purpose was to evaluate the practical dosimetric problems associated with inhomogeneous dose distribution within the irradiated volume in open air state using glass dosimeter and Gafchromic EBT film dosimeter for routine Gamma irradiator dosimetry applications at the KIRAMS and the measurements were compared with each other. In addition, an user guideline for useful utilization of the device based on practical dosimetry will be prepared. The measurement results of uniformity of delivered dose within the device showed variation more than 14% between middle point and the lowest position at central axis. Therefore, to maintain dose variation within 10%, the criteria of useful dose distribution, for research radiation effects, the irradiated specimen located at central axis of the container should be placed within 30 mm from top and bottom surface, respectively. In addition, for measurements using the film, the variations of dose distribution were more then 50% for the case of less than 10 second irradiation, mostly within 20% for the case of more than 20 second irradiation, respectively. Therefore, the irradiation experiments using the BioBeam 8000 irradiator are recommended to be used for specimen required at least more than 20 second irradiation time.

Determination of dose received by bladder and rectum in external cervical irradiation

International Nuclear Information System (INIS)

Omer, Mohamed Ahmed Ali

2001-12-01

The cervical carcinoma is the common type of malignant tumor among sudanese females during the last years. The conventional external irradiation therapy is the common model of treatment for cervical carcinoma in (RICK). The irradiation of such cases implemented via four fields (box technique), two anterior and posterior and two lateral opposed fields, as central dose calculation, giving a dose of 5000 c Gy fractionated into 25 to 30 fractions. The parameter of the fields lie at the promontory of the sacral cephalic and at the obturators foramen caudally and laterally at the bony pelvic by one centimeter. The aim of the research is to determine the dose received by the rectum and bladder (critical organs), out of central dose calculation versus off axis dose calculation to (Day's method). The data obtained by using simulator and radiation oncological computerized system (Rocs). The results are analyzed by using statistical processing for social science program (SPSS) that shows the mean dose received by the bladder is 3821 cGy, due to central dose calculation that accompanied by an un-optimum encompassment of treatment line and 4210.6 c Gy. due to Off Axis Dose calculation dose 3324.4 c Gy and 3712.1 c Gy due to central dose calculation. The increment of dose received by the rectum and the bladder is due to utilizing of wider width of the filed size for lateral irradiation. To score the aim of International Atomic Energy Agency (IAEA) and (ALARA) principle A s Low As As Reasonable Available , we have to use the simulator to obtain the anatomical structures on the contour, or will be better to use CT. Scan for calculation of dose at the side of interest. (Author)

Evaluation of set-of errors in pelvic irradiation with electronic portal imaging device

International Nuclear Information System (INIS)

Wu Xiaoying; Zhang Zhen; Wang Wenchao; Ren Jun; Guo Xiaomei; Lu Huizhong

2007-01-01

Objective: Evaluate the systematic and random set-up error in the pelvic irradiation u- sing electronic portal imaging device(EPID) to provide institution-specific margin for PTV design in pelvic cancer treatment planning with 3D conformal therapy and/or IMRT. Methods: From May to August 2005, twelve patients who received pelvic irradiation, were involved in this study. CT simulations were performed and DRRs were generated as the reference images. Ant-post and lateral portal images were taken daily, and total of 244 sets of EPID images were collected for the whole group. The translational shifts along right-left, superior-inferior and anterior-posterior directions were calculated with aligning the pelvic bony structures on the DRRs and electronic portal images. The systematic and random setup errors were evaluated based on the 244 sets of data. PTV margin was assessed assuming target rotation was negligible. Results: In the right- left (R-L), superior-inferior (S-I) and anterior-posterior (A-P) directions, the maximum shifts were 9.9, 14.0 and 21.1 mm and the systematic setup errors were 0.5, 0.2 and 2.3 mm respectively. For all 244 sets of data in this study, the frequency of the shift larger than 10 mm were 0% (R-L), 1% (S-I) and 3% (A -P); and in R-L and S-I direction, 92% and 91% of the times the shift was smaller than 5 mm. However, only 79% of the times the A-P shift was less than 5 mm. Conclusions: It is suggested in this study that in order to achieve a target coverage of better than 95% of the times throughout the pelvic irradiation in our institution, a 5 mm PTV margin in right-left and superior-inferior directions is required, however, the anterior-posterior margin needs to be increased to at least 10 mm. One needs to be cautious though when applying the PTV margin derived from small sample of patient population to individual patient. (authors)

Gastrointestinal toxicity of vorinostat: reanalysis of phase 1 study results with emphasis on dose-volume effects of pelvic radiotherapy

LENUS (Irish Health Repository)

Bratland, Ase

2011-04-08

Abstract Background In early-phase studies with targeted therapeutics and radiotherapy, it may be difficult to decide whether an adverse event should be considered a dose-limiting toxicity (DLT) of the investigational systemic agent, as acute normal tissue toxicity is frequently encountered with radiation alone. We have reanalyzed the toxicity data from a recently conducted phase 1 study on vorinostat, a histone deacetylase inhibitor, in combination with pelvic palliative radiotherapy, with emphasis on the dose distribution within the irradiated bowel volume to the development of DLT. Findings Of 14 eligible patients, three individuals experienced Common Terminology Criteria of Adverse Events grade 3 gastrointestinal and related toxicities, representing a toxicity profile vorinostat has in common with radiotherapy to pelvic target volumes. For each study patient, the relative volumes of small bowel receiving radiation doses between 6 Gy and 30 Gy at 6-Gy intervals (V6-V30) were determined from the treatment-planning computed tomography scans. The single patient that experienced a DLT at the second highest dose level of vorinostat, which was determined as the maximum-tolerated dose, had V6-V30 dose-volume estimates that were considerably higher than any other study patient. This patient may have experienced an adverse radiation dose-volume effect rather than a toxic effect of the investigational drug. Conclusions When reporting early-phase trial results on the tolerability of a systemic targeted therapeutic used as potential radiosensitizing agent, radiation dose-volume effects should be quantified to enable full interpretation of the study toxicity profile. Trial registration ClinicalTrials.gov: NCT00455351

Gastrointestinal toxicity of vorinostat: reanalysis of phase 1 study results with emphasis on dose-volume effects of pelvic radiotherapy

International Nuclear Information System (INIS)

Bratland, Åse; Dueland, Svein; Hollywood, Donal; Flatmark, Kjersti; Ree, Anne H

2011-01-01

In early-phase studies with targeted therapeutics and radiotherapy, it may be difficult to decide whether an adverse event should be considered a dose-limiting toxicity (DLT) of the investigational systemic agent, as acute normal tissue toxicity is frequently encountered with radiation alone. We have reanalyzed the toxicity data from a recently conducted phase 1 study on vorinostat, a histone deacetylase inhibitor, in combination with pelvic palliative radiotherapy, with emphasis on the dose distribution within the irradiated bowel volume to the development of DLT. Of 14 eligible patients, three individuals experienced Common Terminology Criteria of Adverse Events grade 3 gastrointestinal and related toxicities, representing a toxicity profile vorinostat has in common with radiotherapy to pelvic target volumes. For each study patient, the relative volumes of small bowel receiving radiation doses between 6 Gy and 30 Gy at 6-Gy intervals (V6-V30) were determined from the treatment-planning computed tomography scans. The single patient that experienced a DLT at the second highest dose level of vorinostat, which was determined as the maximum-tolerated dose, had V6-V30 dose-volume estimates that were considerably higher than any other study patient. This patient may have experienced an adverse radiation dose-volume effect rather than a toxic effect of the investigational drug. When reporting early-phase trial results on the tolerability of a systemic targeted therapeutic used as potential radiosensitizing agent, radiation dose-volume effects should be quantified to enable full interpretation of the study toxicity profile.

Reconstructive surgery for the complications of pelvic irradiation

International Nuclear Information System (INIS)

Bricker, E.M.; Johnston, W.D.; Kraybill, W.G.; Lopez, M.J.

1984-01-01

Severe damage to the pelvic viscera is a complication of irradiation therapy that, unfortunately, cannot always be avoided. Resulting rectal and rectocolonic strictures, rectovaginal fistulas, and shortening and stenosis of the vagina present very difficult problems that frequently require a colostomy for relief and may permanently impair sexual function. The authors present a new approach to correction of these unfortunate lesions based on the use of proximal nonirradiated colon which serves as a vascular pedicle graft to correct the defect without a complicated and massive resection. Twenty-two such operations have been done with 19 satisfactory to excellent results and two total failures (one death from small bowel complications). All patterns and combinations of irradiation injury have been found amenable to this technique of repair. These have included both web and linear strictures with and without fistulas. In half of the patients, it was possible to make use of normal colon bypassed by a prior colostomy. Normal nonirradiated colon with good blood supply will heal satisfactorily to irradiated colon or rectum, thus making excision of all the irradiated tissue unnecessary. The results of this surgical approach have thus far been gratifying and warrant further trials for these distressing injuries

High-dose irradiation of food

International Nuclear Information System (INIS)

Diehl, J.F.

1999-01-01

Studies performed on behalf of the International Project on Food Irradiation in the period from 1971 until 1980 resulted in the concluding statement that ''.the irradiation of any food commodity up to an overall average dose of 10 kGy presents no toxicological hazard; hence, toxicological testing of foods so treated is no longer required.'' Since then, licenses for food irradiation have been restricted to this maximum dose in any country applying this technology. Further testing programmes have been carried out investigating the wholesomeness or hazards of high-dose irradiation, but there has been little demand so far by the food industry for licensing of high-dose irradiation, as there is only a small range of products whose irradiation at higher doses offers advantages for given, intended use. These include eg. spices, dried herbs, meat products in flexible pouch packagings for astronauts, or patients with immune deficiencies. (orig./CB) [de

Is There a Role for Pelvic Irradiation in Localized Prostate Adenocarcinoma? Update of the Long-Term Survival Results of the GETUG-01 Randomized Study

Energy Technology Data Exchange (ETDEWEB)

Pommier, Pascal, E-mail: Pascal.pommier@lyon.unicancer.fr [Department of Radiation Oncology, Centre Léon Bérard, Lyon (France); Chabaud, Sylvie [Department of Clinical Research and Innovation, Centre Léon Bérard, Lyon (France); Lagrange, Jean-Leon [Department of Radiation Oncology, Centre Hospitalo-Universitaire H. Mondor, Créteil (France); Richaud, Pierre [Department of Radiation Oncology, Institut Bergognié, Bordeaux (France); Le Prise, Elisabeth [Department of Radiation Oncology, Centre Eugène Marquis, Rennes (France); Wagner, Jean-Philippe [Department of Radiation Oncology, Institut Andrée Dutreix, Dunkerque (France); Azria, David [Department of Radiation Oncology, Institut de Cancérologie de Montpellier, Montpellier (France); Beckendorf, Veronique [Department of Radiation Oncology, Institut de Cancérologie de Lorraine, Nancy (France); Suchaud, Jean-Philippe [Department of Radiation Oncology, Centre Hospitalier de Roanne, Roanne (France); Bernier, Valerie [Department of Radiation Oncology, Centre Oscar Lambret, Lille (France); Perol, David [Department of Clinical Research and Innovation, Centre Léon Bérard, Lyon (France); Carrie, Christian [Department of Radiation Oncology, Centre Léon Bérard, Lyon (France)

2016-11-15

Purpose: To report the long-term results of the French Genitourinary Study Group (GETUG)-01 study in terms of event-free survival (EFS) and overall survival (OS) and assess the potential interaction between hormonotherapy and pelvic nodes irradiation. Patients and Methods: Between December 1998 and June 2004, 446 patients with T1b-T3, N0pNx, M0 prostate carcinoma were randomly assigned to either pelvic nodes and prostate or prostate-only radiation therapy. Patients were stratified into 2 groups: “low risk” (T1-T2 and Gleason score 6 and prostate-specific antigen <3× the upper normal limit of the laboratory) (92 patients) versus “high risk” (T3 or Gleason score >6 or prostate-specific antigen >3× the upper normal limit of the laboratory). Short-term 6-month neoadjuvant and concomitant hormonal therapy was allowed only for high-risk patients. Radiation therapy was delivered with a 3-dimensional conformal technique, using a 4-field technique for the pelvic volume (46 Gy). The total dose recommended to the prostate moved from 66 Gy to 70 Gy during the course of the study. Criteria for EFS included biologic prostate-specific antigen recurrences and/or a local or metastatic progression. Results: With a median follow-up of 11.4 years, the 10-year OS and EFS were similar in the 2 treatment arms. A higher but nonsignificant EFS was observed in the low-risk subgroup in favor of pelvic nodes radiation therapy (77.2% vs 62.5%; P=.18). A post hoc subgroup analysis showed a significant benefit of pelvic irradiation when the risk of lymph node involvement was <15% (Roach formula). This benefit seemed to be limited to patients who did not receive hormonal therapy. Conclusion: Pelvic nodes irradiation did not statistically improve EFS or OS in the whole population but may be beneficial in selected low- and intermediate-risk prostate cancer patients treated with exclusive radiation therapy.

Dose perturbation due to the presence of a prostatic urethral stent in patients receiving pelvic radiotherapy: an in vitro study.

Science.gov (United States)

Gez, E; Cederbaum, M; Yachia, D; Bar-Deroma, R; Kuten, A

1997-01-01

Temporary metallic intraprostatic stent is a new alternative treatment for patients with urinary obstructive syndrome caused by prostate cancer. Definitive radiotherapy is a treatment of choice for localized prostate cancer. This study evaluates in vitro the effect of a urethral intraprostatic metallic stent on the dose absorbed by the surrounding tissue. The study was designed to mimic the conditions under which the prostatic stent is placed in the body during pelvic irradiation. A urethral stent composed of a 50% nickel-50% titanium alloy (Uracoil-InStent) was imbedded in material mimicking normal tissue (bolus) at a simulated body depth of 10 cm. The distribution of the absorbed dose of irradiation was determined by film dosimetry using Kodak X-Omat V film. Irradiation was done in a single field at the isocenter of a 6 MV linear accelerator with a field size of 7 x 7 cm. The degree of film blackening was in direct proportion to the absorbed dose. The measurements showed an increase in dose of up to 20% immediately before the stent and a decrease of up to 18% immediately after the stent. These changes occurred within a range of 1-3 mm from both sides of the stent. In practice, irradiation in prostate cancer is given by two pairs of opposed co-axial fields; a total of four fields (Box Technique). The dose perturbations are partly cancelled in a pair of opposed beams resulting in a net variation of +/- 4%; therefore, the presence of the intraprostatic stent should not influence radiotherapy planning for prostate cancer.

Tolerance and efficiency of radiation therapy treatment of the pelvic lymph nodes in patients with prostate cancer

International Nuclear Information System (INIS)

Hegemann, Nina-Sophie

2013-01-01

Tolerance and efficiency of radiation therapy treatment of the pelvic lymph nodes were assessed in 122 patients with prostate cancer. With no severe observed late toxicity the incidence for lymph node metastases was between 3,0% (primarily irradiated patients without lymph node or distant metastases) and 100% (primarily irradiated patients with lymph node and distant metastases) after 3 years. As it seems, the following subgroups might possibly profit the most from a dose escalation in the pelvic lymph nodes: primarily irradiated patients with positive lymph nodes and postoperatively irradiated patients in adjuvant/additive situation, with a biochemical or a local/lymph node recurrence.

Irradiation of the prostate and pelvic lymph nodes with an adaptive algorithm

International Nuclear Information System (INIS)

Hwang, A. B.; Chen, J.; Nguyen, T. B.; Gottschalk, A. G.; Roach, M. R. III; Pouliot, J.

2012-01-01

Purpose: The simultaneous treatment of pelvic lymph nodes and the prostate in radiotherapy for prostate cancer is complicated by the independent motion of these two target volumes. In this work, the authors study a method to adapt intensity modulated radiation therapy (IMRT) treatment plans so as to compensate for this motion by adaptively morphing the multileaf collimator apertures and adjusting the segment weights. Methods: The study used CT images, tumor volumes, and normal tissue contours from patients treated in our institution. An IMRT treatment plan was then created using direct aperture optimization to deliver 45 Gy to the pelvic lymph nodes and 50 Gy to the prostate and seminal vesicles. The prostate target volume was then shifted in either the anterior-posterior direction or in the superior-inferior direction. The treatment plan was adapted by adjusting the aperture shapes with or without re-optimizing the segment weighting. The dose to the target volumes was then determined for the adapted plan. Results: Without compensation for prostate motion, 1 cm shifts of the prostate resulted in an average decrease of 14% in D-95%. If the isocenter is simply shifted to match the prostate motion, the prostate receives the correct dose but the pelvic lymph nodes are underdosed by 14% ± 6%. The use of adaptive morphing (with or without segment weight optimization) reduces the average change in D-95% to less than 5% for both the pelvic lymph nodes and the prostate. Conclusions: Adaptive morphing with and without segment weight optimization can be used to compensate for the independent motion of the prostate and lymph nodes when combined with daily imaging or other methods to track the prostate motion. This method allows the delivery of the correct dose to both the prostate and lymph nodes with only small changes to the dose delivered to the target volumes.

Irradiation dose of cosmonauts

International Nuclear Information System (INIS)

Makra, Zs.

1978-01-01

The results obtained by determining the irradiation dose during the spaceflights of Apollo as well as the Sojouz-3 and Sojouz-9 spacecrafts have been compared in the form of tables. In case of Apollo astronauts the irradiation dose was determined by two methods and its sources were also pointed out, in tables. During Sojouz spacetravels the cosmonauts were exposed to a negligible dose. In spite of this fact the radiation danger is considerable. The small irradiation doses noticed so far are due to the fact that during the spaceflights there was no big proturberance. However, during the future long-range spacetravels a better radiation shielding than the one used up to now will be necessary. (P.J.)

A method for evaluation of proton plan robustness towards inter-fractional motion applied to pelvic lymph node irradiation

DEFF Research Database (Denmark)

Andersen, Andreas G; Casares-Magaz, Oscar; Muren, Ludvig P

2015-01-01

of the pelvic lymph nodes (LNs) from different beam angles. Patient- versus population-specific patterns in dose deterioration were explored. MATERIAL AND METHODS: Patient data sets consisting of a planning computed tomography (pCT) as well as multiple repeat CT (rCT) scans for three patients were used......BACKGROUND: The benefit of proton therapy may be jeopardized by dose deterioration caused by water equivalent path length (WEPL) variations. In this study we introduced a method to evaluate robustness of proton therapy with respect to inter-fractional motion and applied it to irradiation...... in deterioration patterns were found for the investigated patients, with beam angles delivering less dose to rectum, bladder and overall normal tissue identified around 40° and around 150°-160° for the left LNs, and corresponding angles for the right LNs. These angles were also associated with low values of WEPL...

Effects of low priming dose irradiation on cell cycle arrest of HepG2 cells caused by high dose irradiation

International Nuclear Information System (INIS)

Xia Jingguang; Jin Xiaodong; Chinese Academy of Sciences, Beijing; Li Wenjian; Wang Jufang; Guo Chuanling; Gao Qingxiang

2005-01-01

Human hepatoma cells hepG2 were irradiated twice by 60 Co γ-rays with a priming dose of 5 cGy and a higher dose of 3 Gy performed 4h or 8h after the low dose irradiation. Effects of the priming dose irradiation on cell cycle arrest caused by high dose were examined with flow cytometry. Cells in G 2 /M phase accumulated temporarily after the 5 cGy irradiation, and proliferation of tumor cells was promoted significantly by the low dose irradiation. After the 3 Gy irradiation, G 2 phase arrest occurred, and S phase delayed temporally. In comparison with 3 kGy irradiation only, the priming dose delivered 4h prior to the high dose irradiation facilitated accumulation of hepG2 cells in G 2 /M phase, whereas the priming dose delivered 8h prior to the high dose irradiation helped the cells to overcome G 2 arrest. It was concluded that effects of the priming dose treatment on cell cycle arrest caused by high dose irradiation were dependent on time interval between the two irradiations. (authors)

Use of the flexible sigmoidoscope in women with previous pelvic irradiation

International Nuclear Information System (INIS)

Sandler, R.S.; Varma, V.; Herbst, C.A. Jr.; Montana, G.S.; Rudnick, S.A.; Fowler, W.C. Jr.

1982-01-01

Pelvic irradiation has been reported to be a risk factor for colonic malignancy. We performed flexible sigmoidoscopy with serial pinch biopsies in 20 asymptomatic women treated with irradiation for cervical cancer more than 10 years ago in order to determine the feasibility of the technique and to detect late radiation effects. The examination was well tolerated by 14 (70%) of the patients, and the instrument was passed to 40 cm in 14 (74%) of 19 women. Abnormal mucosal or vascular changes were found in 12 (60%) and nonspecific microscopic abnormalities were seen in 18 (90%) of the 20 women

Study of positional dependence of dose to bladder, pelvic wall and rectal points in High-Dose-Rate Brachytherapy in cervical cancer patients

International Nuclear Information System (INIS)

Talluri, Anil Kumar; Alluri, Krishnam Raju; Gudipudi, Deleep Kumar; Ahamed, Shabbir; Sresty, Madhusudhana M.; Reddy, Aparna Yarrama

2013-01-01

The objective of the study is to examine the variation in doses to, Bladder, pelvic wall and Rectal Points when a patient is simulated in Supine (S Position) and Lithotomy M shaped positions (LM Position), respectively as part of Intracavitary Brachytherapy in Cervical Cancer patients. Patients (n = 19) were simulated and orthogonal images were taken in S Position and LM Positions on a physical simulator. Digital orthogonal X-ray images were transferred to Brachyvision Treatment Planning System via Dicom to generate treatment plans. Radio opaque dye of 7 ml was injected into the Foley bulb for identification and digitization of International Commission on Radiological Units and Measurements (ICRU) Bladder point. Pelvic side wall points were marked in accordance with ICRU 38 recommendations. A Rectal tube containing dummy source marker wire was used to identify Rectal Point. Students' t-test was used to analyze the results. Doses in LM Position were lower and statistically significant when compared to S Position for ICRU Bladder Point, pelvic walls and Rectal Point. It was observed that movement of applicator could be the reason for the variations in doses between the two positions. Bladder, pelvic wall and rectal points systematically registered lower doses in LM Position as compared to S Position. (author)

Pathological response of locally advanced rectal cancer to preoperative chemotherapy without pelvic irradiation.

Science.gov (United States)

Bensignor, T; Brouquet, A; Dariane, C; Thirot-Bidault, A; Lazure, T; Julié, C; Nordlinger, B; Penna, C; Benoist, S

2015-06-01

Pathological response to chemotherapy without pelvic irradiation is not well defined in rectal cancer. This study aimed to evaluate the objective pathological response to preoperative chemotherapy without pelvic irradiation in middle or low locally advanced rectal cancer (LARC). Between 2008 and 2013, 22 patients with middle or low LARC (T3/4 and/or N+ and circumferential resection margin rectal resection after preoperative chemotherapy. The pathological response of rectal tumour was analysed according to the Rödel tumour regression grading (TRG) system. Predictive factors of objective pathological response (TRG 2-4) were analysed. All patients underwent rectal surgery after a median of six cycles of preoperative chemotherapy. Of these, 20 (91%) had sphincter saving surgery and an R0 resection. Twelve (55%) patients had an objective pathological response (TRG 2-4), including one complete response. Poor response (TRG 0-1) to chemotherapy was noted in 10 (45%) patients. In univariate analyses, none of the factors examined was found to be predictive of an objective pathological response to chemotherapy. At a median follow-up of 37.2 months, none of the 22 patients experienced local recurrence. Of the 19 patients with Stage IV rectal cancer, 15 (79%) had liver surgery with curative intent. Preoperative chemotherapy without pelvic irradiation is associated with objective pathological response and adequate local control in selected patients with LARC. Further prospective controlled studies will address the question of whether it can be used as a valuable alternative to radiochemotherapy in LARC. Colorectal Disease © 2014 The Association of Coloproctology of Great Britain and Ireland.

Dose distribution of non-coplanar irradiation

Energy Technology Data Exchange (ETDEWEB)

Fukui, Toshiharu; Wada, Yoichi; Takenaka, Eiichi

1987-02-01

Non-coplanar irradiations were applied to the treatment of brain tumor. The dose distribution around the target area due to non-coplanar irradiation was half less than the dose when coplanar irradiation used. Integral volume dose due to this irradiation was not always less than that due to conventional opposing or rotational irradiation. This irradiation has the better application to the following;as a boost therapy, glioblastoma multiforme;as a radical therapy, recurrent brain tumor, well differentiated brain tumor such as craniopharyngioma, hypophyseal tumor etc and AV-malformation.

Normal tissue tolerance to external beam radiation therapy: Testicles; Dose de tolerance a l'irradiation des tissus sain: les testicules

Energy Technology Data Exchange (ETDEWEB)

Champetier, C.; Gross, E.; Zaccariotto, A.; Duberge, T.; Guerder, C. [Service de radiotherapie, hopital de la Timone, 13 - Marseille (France); Pointreau, Y. [Pole Henry-S.-Kaplan, CHU Bretonneau, 37 - Tours (France); Ortholan, C. [Centre Antoine-Lacassagne, 06 - Nice (France); Chauvet, B. [Institut Sainte-Catherine, 84 - Avignon (France)

2010-07-15

Although there is very little evidence for direct irradiation of the testes, they may receive significant doses, especially in the treatment of pelvic tumors in adults and in pediatrics. The exocrine function of the testis seems to be more sensitive to radiotherapy. There is a risk of sterility, even after low doses of radiation. In the adult or the child who has reached puberty, we should propose a self-preservation of semen prior to radiotherapy. In pre-pubescent children, the problem is more delicate. In all cases, it is necessary to limit the dose to the testicles without affecting the coverage of tumour volume. Patients and/or their care-givers should be systematically informed of the risk of infertility related to irradiation. (authors)

Dose mapping in category I irradiators

International Nuclear Information System (INIS)

Mondal, Sandip; Shinde, S.H.; Mhatre, S.G.V.

2012-01-01

Category I irradiators such as Gamma Chambers and Blood Irradiators are compact self shielded, dry source storage gamma irradiators offering irradiation volume of few hundred cubic centimeters. In the present work, dose distribution profiles along the central vertical plane of the irradiation volume of Gamma Chamber 900 and Blood Irradiator 2000 were measured using Fricke, FBX, and alanine dosimeters. Measured dose distribution profiles in Gamma Chamber 900 differed from the typical generic dose distribution pattern whereas that in Blood Irradiator 2000 was in agreement with the typical pattern. All reagents used were of analytical reagent grade and were used without further purification. Preparation and dose estimations of Fricke and FBX were carried out as recommended. Alanine pellets were directly placed in precleaned polystyrene container having dimensions 6.5 mm o.d., 32 mm height and 3 mm wall thickness. For these dosimeters, dose measurements were made using e-scan Bruker BioSpin alanine dedicated ESR spectrometer. Specially designed perspex jigs were used during irradiation in Gamma Chamber 900 and Blood Irradiator 2000. These jigs provided the reproducible geometry during irradiation, Absorbance measurements were made using a spectrophotometer calibrated as per the recommended procedure. In Gamma Chamber 900, there is a dose distribution variation of about 34% from top to the center, 18% from center to the bottom, and 15% from center to the periphery. Such a dose distribution profile is largely deviating from the typical profile wherein 15% variation is observed from center to the periphery on all sides. Further investigation showed that there was a nonalignment in the source and sample chamber. However, in Blood Irradiator 2000, there is a dose distribution variation of about 20% from top to the center, 15% from center to the bottom, and 12% from center to the periphery. This pattern is very much similar to the typical profile. Hence it is recommended

Phase I Trial of Pelvic Nodal Dose Escalation With Hypofractionated IMRT for High-Risk Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Adkison, Jarrod B.; McHaffie, Derek R.; Bentzen, Soren M.; Patel, Rakesh R.; Khuntia, Deepak [Department of Human Oncology, University of Wisconsin Carbone Cancer Center, School of Medicine and Public Health, Madison, WI (United States); Petereit, Daniel G. [Department of Radiation Oncology, John T. Vucurevich Regional Cancer Care Institute, Rapid City Regional Hospital, Rapid City, SD (United States); Hong, Theodore S.; Tome, Wolfgang [Department of Human Oncology, University of Wisconsin Carbone Cancer Center, School of Medicine and Public Health, Madison, WI (United States); Ritter, Mark A., E-mail: ritter@humonc.wisc.edu [Department of Human Oncology, University of Wisconsin Carbone Cancer Center, School of Medicine and Public Health, Madison, WI (United States)

2012-01-01

Purpose: Toxicity concerns have limited pelvic nodal prescriptions to doses that may be suboptimal for controlling microscopic disease. In a prospective trial, we tested whether image-guided intensity-modulated radiation therapy (IMRT) can safely deliver escalated nodal doses while treating the prostate with hypofractionated radiotherapy in 5 Vulgar-Fraction-One-Half weeks. Methods and Materials: Pelvic nodal and prostatic image-guided IMRT was delivered to 53 National Comprehensive Cancer Network (NCCN) high-risk patients to a nodal dose of 56 Gy in 2-Gy fractions with concomitant treatment of the prostate to 70 Gy in 28 fractions of 2.5 Gy, and 50 of 53 patients received androgen deprivation for a median duration of 12 months. Results: The median follow-up time was 25.4 months (range, 4.2-57.2). No early Grade 3 Radiation Therapy Oncology Group or Common Terminology Criteria for Adverse Events v.3.0 genitourinary (GU) or gastrointestinal (GI) toxicities were seen. The cumulative actuarial incidence of Grade 2 early GU toxicity (primarily alpha blocker initiation) was 38%. The rate was 32% for Grade 2 early GI toxicity. None of the dose-volume descriptors correlated with GU toxicity, and only the volume of bowel receiving {>=}30 Gy correlated with early GI toxicity (p = 0.029). Maximum late Grades 1, 2, and 3 GU toxicities were seen in 30%, 25%, and 2% of patients, respectively. Maximum late Grades 1 and 2 GI toxicities were seen in 30% and 8% (rectal bleeding requiring cautery) of patients, respectively. The estimated 3-year biochemical control (nadir + 2) was 81.2 {+-} 6.6%. No patient manifested pelvic nodal failure, whereas 2 experienced paraaortic nodal failure outside the field. The six other clinical failures were distant only. Conclusions: Pelvic IMRT nodal dose escalation to 56 Gy was delivered concurrently with 70 Gy of hypofractionated prostate radiotherapy in a convenient, resource-efficient, and well-tolerated 28-fraction schedule. Pelvic nodal dose

Re-irradiation: Outcome, cumulative dose and toxicity in patients retreated with stereotactic radiotherapy in the abdominal or pelvic region

NARCIS (Netherlands)

H. Abusaris (Huda); M.S. Hoogeman (Mischa); J.J.M.E. Nuyttens (Joost)

2012-01-01

textabstractThe purpose of the present study was to explore the outcome, cumulative dose in tumor and organs at risk and toxicity after extra-cranial stereotactic re-irradiation. Twenty-seven patients were evaluated who had been re-irradiated with stereotactic body radiotherapy (SBRT) after

Comparison of low dose with standard dose abdominal/pelvic multidetector CT in patients with stage 1 testicular cancer under surveillance

Energy Technology Data Exchange (ETDEWEB)

O' Malley, Martin E. [Joint Department of Medical Imaging, Toronto, ON (Canada); Chung, Peter; Warde, Padraig [Princess Margaret Hospital, Department of Radiation Oncology, Toronto, ON (Canada); Haider, Masoom; Jhaveri, Kartik; Khalili, Korosh [Princess Margaret Hospital, Joint Department of Medical Imaging, Toronto, ON (Canada); Jang, Hyun-Jung [Toronto General Hospital, Joint Department of Medical Imaging, Toronto, ON (Canada); Panzarella, Tony [Princess Margaret Hospital, Department of Biostatistics, Toronto, ON (Canada)

2010-07-15

To compare the image quality and acceptability of a low dose with those of standard dose abdominal/pelvic multidetector CT in patients with stage 1 testicular cancer managed by surveillance. One hundred patients (median age 31 years; range 19-83 years), 79 with seminoma and 21 with non-seminoma, underwent abdominal/pelvic imaging with low and standard dose protocols on 64-slice multidetector CT. Three reviewers independently evaluated images for noise and diagnostic quality on a 5-point scale and for diagnostic acceptability. On average, each reader scored noise and diagnostic quality of standard dose images significantly better than corresponding low dose images (p < 0.0001). One reader found all CT examinations acceptable; two readers each found 1/100 (1%) low dose examinations unacceptable. Median and mean dose-length product for low and standard dose protocols were 416.0 and 452.2 (range 122.9-913.4) and 931.9 and 999.8 (range 283.8-1,987.7) mGy cm, respectively. The low dose protocol provided diagnostically acceptable images for at least 99% of patients and achieved mean dose reduction of 55% compared with the standard dose protocol. (orig.)

Re-irradiation for abdominal tumor. Preliminary results

International Nuclear Information System (INIS)

Narisada, Hiroyuki; Imada, Hajime; Tomoda, Yoshinori

2012-01-01

The purpose of this study was to assess the efficacy of loco-regional radiotherapy for recurrent abdominal tumor treated with re-irradiation. Re-irradiated areas of 16 patients were eight of pelvic space, five of retroperitonium and three of liver or porta hepatica. Eligibility criteria of re-irradiation were success of initial irradiation, no other effective treatment except re-irradiation, constancy of bowel gas at hunger status and respiratory movement, visceral dosage reduction at re-irradiation. Total dose of initial, second course of radiation were 51.3±10.8 Gy, 50.6±14.2 Gy, respectively. Interval of initial and second course of radiation were 16.6±10.2 months. Local control after second course of radiation was four cases of complete response, five of partial response and seven of stable disease. Median survival periods were 55 months after initial treatment and 28 months after second course of radiation. In two cases of pelvic reirradiation, skin to pelvic space fistula was occurred. Re-irradiation for abdominal tumor may become useful salvage treatment. (author)

Intracranial meningiomas after high-dose irradiation

International Nuclear Information System (INIS)

Soffer, D.; Gomori, J.M.; Siegal, T.; Shalit, M.N.

1989-01-01

Three patients who presented with intracranial meningiomas 12, 15, and 20 years, respectively, after therapeutic high-dose irradiation of a primary brain tumor are described. Analysis of these cases and similar documented cases suggests that meningiomas after high-dose irradiation constitute a recognizable entity. Patients with such tumors received radiation therapy at a young age (mean age, 9.4 years). After a latent period of 2 to 47 years (mean, 19.8 years) they developed meningiomas at the site of irradiation, at a much younger age than patients with ''spontaneous'' meningiomas. Similar to the situation with meningiomas after low-dose irradiation, a relatively high proportion of meningiomas induced by high-dose irradiation tend to be malignant and biologically aggressive. A very young age at the time of irradiation seems to predispose to the induction of malignant meningiomas, rather than benign tumors. These unusual features provide indirect evidence that high-dose radiation may play a role in the pathogenesis of meningiomas.41 references

Pelvic nodal dose escalation with prostate hypofractionation using conformal avoidance defined (H-CAD) intensity modulated radiation therapy

International Nuclear Information System (INIS)

Hong, Theodore S.; Tome, Wolfgang A.; Jaradat, Hazim; Raisbeck, Bridget M.; Ritter, Mark A.

2006-01-01

The management of prostate cancer patients with a significant risk of pelvic lymph node involvement is controversial. Both whole pelvis radiotherapy and dose escalation to the prostate have been linked to improved outcome in such patients, but it is unclear whether conventional whole pelvis doses of only 45-50 Gy are optimal for ultimate nodal control. The purpose of this study is to examine the dosimetric and clinical feasibility of combining prostate dose escalation via hypofractionation with conformal avoidance-based IMRT (H-CAD) dose escalation to the pelvic lymph nodes. One conformal avoidance and one conventional plan were generated for each of eight patients. Conformal avoidance-based IMRT plans were generated that specifically excluded bowel, rectum, and bladder. The prostate and lower seminal vesicles (PTV 70) were planned to receive 70 Gy in 2.5 Gy/fraction while the pelvic lymph nodes (PTV 56) were to concurrently receive 56 Gy in 2 Gy/fraction. The volume of small bowel receiving >45 Gy was restricted to 300 ml or less. These conformal avoidance plans were delivered using helical tomotherapy or LINAC-based IMRT with daily imaging localization. All patients received neoadjuvant and concurrent androgen deprivation with a planned total of two years. The conventional, sequential plans created for comparison purposes for all patients consisted of a conventional 4-field pelvic box prescribed to 50.4 Gy (1.8 Gy/fraction) followed by an IMRT boost to the prostate of 25.2 Gy (1.8 Gy/fraction) yielding a final prostate dose of 75.6 Gy. For all plans, the prescription dose was to cover the target structure. Equivalent uniform dose (EUD) analyses were performed on all targets and dose-volume histograms (DVH) were displayed in terms of both physical and normalized total dose (NTD), i.e. dose in 2 Gy fraction equivalents. H-CAD IMRT plans were created for and delivered to all eight patients. Analysis of the H-CAD plans demonstrates prescription dose coverage of >95

Offline multiple adaptive planning strategy for concurrent irradiation of the prostate and pelvic lymph nodes

International Nuclear Information System (INIS)

Qi, Peng; Xia, Ping; Pouliot, Jean; Roach, Mack

2014-01-01

Purpose: Concurrent irradiation of the prostate and pelvic lymph nodes (PLNs) can be challenging due to the independent motion of the two target volumes. To address this challenge, the authors have proposed a strategy referred to as Multiple Adaptive Planning (MAP). To minimize the number of MAP plans, the authors’ previous work only considered the prostate motion in one major direction. After analyzing the pattern of the prostate motion, the authors investigated a practical number of intensity-modulated radiotherapy (IMRT) plans needed to accommodate the prostate motion in two major directions simultaneously. Methods: Six patients, who received concurrent irradiation of the prostate and PLNs, were selected for this study. Nine MAP-IMRT plans were created for each patient with nine prostate contours that represented the prostate at nine locations with respect to the PLNs, including the original prostate contour and eight contours shifted either 5 mm in a single anterior-posterior (A-P), or superior-inferior (S-I) direction, or 5 mm in both A-P and S-I directions simultaneously. From archived megavoltage cone beam CT (MV-CBCT) and a dual imaging registration, 17 MV-CBCTs from 33 available MV-CBCT from these patients showed large prostate displacements (>3 mm in any direction) with respect to the pelvic bones. For each of these 17 fractions, one of nine MAP-IMRT plans was retrospectively selected and applied to the MV-CBCT for dose calculation. For comparison, a simulated isocenter-shifting plan and a reoptimized plan were also created for each of these 17 fractions. The doses to 95% (D95) of the prostate and PLNs, and the doses to 5% (D5) of the rectum and bladder were calculated and analyzed. Results: For the prostate, D95 > 97% of the prescription dose was observed in 16, 16, and 17 of 17 fractions for the MAP, isocenter-shifted, and reoptimized plans, respectively. For PLNs, D95 > 97% of the prescription doses was observed in 10, 3, and 17 of 17 fractions for

Dose volume relationships for intraoperatively irradiated saphenous nerve

International Nuclear Information System (INIS)

Gillette, E.L.; Powers, B.E.; Gillette, S.M.; Thames, H.D.; Childs, G.; Vujaskovic, Z.; LaRue, S.M.

1995-01-01

Purpose/Objective: Intraoperative radiation therapy (IORT) is used to deliver high single doses of radiation to the tumor bed following surgical removal of various abdominal malignancies. The advantage of IORT is the ability to remove sensitive normal tissues from the treatment field and to limit the volume of normal tissue irradiated. The purpose of this study was to determine dose-volume relationships for retroperitoneal tissues. Materials and methods: 134 adult beagle dogs were irradiated to the surgically exposed paraaortic area. Normal tissues included in the treatment field were aorta, peripheral nerve, ureter, bone and muscle. Groups of 4 - 8 dogs were irradiated to doses ranging from 18 - 54 Gy for a 2x5 cm field, from 12 - 46 Gy for a 4x5 cm field, and 12 - 42 Gy to an 8x5 cm field. The radiations were done using 6 MeV electrons from a linear accelerator. Dogs were observed for three years after radiation. Electrophysiologic procedures were done prior to irradiation and annually following irradiation. The procedures included electromyography of the pelvic limb and paralumbar muscles supplied by the L1 to S1 spinal nerves to determine presence and degree of motor unit disease. Motor nerve conduction velocities of the proximal and distal sciatic nerves were determined. Sensory nerve conduction velocities of the saphenous nerve were also determined. Evoked lumbosacral and thoraco-lumbar spinal cord potentials were evaluated following stimulation of the left sciatic nerve. In addition to electrophysiologic studies, neurologic examinations were done prior to treatment and at six month intervals for the three year observation period. At the three year time period, dogs were euthanatized, sections of peripheral nerve taken, routinely processed, stained with Masson's trichrome and evaluated histomorphometrically using point count techniques. Results: Twenty-two dogs were euthanatized prior to the three year observation period due to peripheral nerve damage

Medium-dose-rate intracavitary brachytherapy for cervical cancer

International Nuclear Information System (INIS)

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

2003-01-01

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

Dose mapping role in gamma irradiation industry

International Nuclear Information System (INIS)

Noriah Mod Ali; John Konsoh Sangau; Mazni Abd Latif

2002-01-01

In this studies, the role of dosimetry activity in gamma irradiator was discussed. Dose distribution in the irradiator, which is a main needs in irradiator or chamber commissioning. This distribution data were used to confirm the dosimetry parameters i.e. exposure time, maximum and minimum dose map/points, and dose distribution - in which were used as guidelines for optimum product irradiation. (Author)

Normal tissue tolerance to external beam radiation therapy: Peripheral nerves; Dose de tolerance a l'irradiation des tissus sains: les nerfs peripheriques

Energy Technology Data Exchange (ETDEWEB)

Henriques de Figueiredo, B.; Dejean, C.; Sargos, P.; Kantor, G. [Departement de radiotherapie, institut Bergonie, centre regional de lutte contre le cancer, 33 - Bordeaux (France); Huchet, A.; Mamou, N. [Service d' oncologie medicale et de radiotherapie, CHU Saint-Andre, 33 - Bordeaux (France); Loiseau, H. [Service de neurochirurgie, CHU Pellegrin, 33 - Bordeaux (France)

2010-07-15

Plexopathies and peripheral neuropathies appear progressively and with several years delay after radiotherapy. These lesions are observed principally after three clinical situations: supraclavicular and axillar irradiations for breast cancer, pelvic irradiations for various pathologies and limb irradiations for soft tissue sarcomas. Peripheral nerves and plexus (brachial and lumbosacral) are described as serial structures and are supposed to receive less than a given maximum dose linked to the occurrence of late injury. Literature data, mostly ancient, define the maximum tolerable dose to a threshold of 60 Gy and highlight also a great influence of fractionation and high fraction doses. For peripheral nerves, most frequent late effects are pain with significant differences of occurrence between 50 and 60 Gy. At last, associated pathologies (diabetes, vascular pathology, neuropathy) and associated treatments have probably to be taken into account as additional factors, which may increase the risk of these late radiation complications. (authors)

Quantitative analysis of biological responses to low dose-rate γ-radiation, including dose, irradiation time, and dose-rate

International Nuclear Information System (INIS)

Magae, J.; Furukawa, C.; Kawakami, Y.; Hoshi, Y.; Ogata, H.

2003-01-01

Full text: Because biological responses to radiation are complex processes dependent on irradiation time as well as total dose, it is necessary to include dose, dose-rate and irradiation time simultaneously to predict the risk of low dose-rate irradiation. In this study, we analyzed quantitative relationship among dose, irradiation time and dose-rate, using chromosomal breakage and proliferation inhibition of human cells. For evaluation of chromosome breakage we assessed micronuclei induced by radiation. U2OS cells, a human osteosarcoma cell line, were exposed to gamma-ray in irradiation room bearing 50,000 Ci 60 Co. After the irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, cytoplasm and nucleus were stained with DAPI and propidium iodide, and the number of binuclear cells bearing micronuclei was determined by fluorescent microscopy. For proliferation inhibition, cells were cultured for 48 h after the irradiation and [3H] thymidine was pulsed for 4 h before harvesting. Dose-rate in the irradiation room was measured with photoluminescence dosimeter. While irradiation time less than 24 h did not affect dose-response curves for both biological responses, they were remarkably attenuated as exposure time increased to more than 7 days. These biological responses were dependent on dose-rate rather than dose when cells were irradiated for 30 days. Moreover, percentage of micronucleus-forming cells cultured continuously for more than 60 days at the constant dose-rate, was gradually decreased in spite of the total dose accumulation. These results suggest that biological responses at low dose-rate, are remarkably affected by exposure time, that they are dependent on dose-rate rather than total dose in the case of long-term irradiation, and that cells are getting resistant to radiation after the continuous irradiation for 2 months. It is necessary to include effect of irradiation time and dose-rate sufficiently to evaluate risk

Technical relapsed testicular irradiation for acute lymphoblastic leukemia

International Nuclear Information System (INIS)

Velazquez Miranda, S.; Delgado Gil, M. M.; Ortiz Siedel, M.; Munoz Carmona, D. M.; Gomez-Barcelona, J.

2011-01-01

Testicular irradiation in children suffering from acute lymphoblastic leukemia presents difficulties in relation to daily positioning, dosimetry for dose homogenization of complex geometry and volume change during irradiation thereof. This can lead to significant deviations from the prescribed doses. In addition, the usual techniques often associated with unnecessary irradiation of pelvic simphysis, anus and perineum. This, in the case of pediatric patients, is of great importance, since doses in the vicinity of 20 Gy are associated with a deviation of bone growth, low testosterone levels around 24 Gy and high rates of generation of second tumors. To overcome these problems we propose a special restraint in prone and non-coplanar irradiation.

14C-lactose breath tests during pelvic radiotherapy: the effect of the amount of small bowel irradiated

International Nuclear Information System (INIS)

Weiss, R.G.; Stryker, J.A.

1982-01-01

Thirty patients who were undergoing pelvic radiotherapy had 14 C-lactose breath tests performed in the first and fifth weeks of treatment. In Group I (21 patients), a significant portion of the small intestine was irradiated, and in Group II (9 patients), only a small portion of the small intestine was irradiated. In Group I, the average reductions in the excretion of ingested 14 C between the first- and fifth-week tests were 41.5% at 1/2 hour postingestion (p 0.05). The data suggest that lactose malabsorption is a factor in the etiology of the nausea, vomiting, and diarrhea experienced by patients who are undergoing pelvic radiotherapy, and that the amount of bowel included in the treatment volume significantly influences the degree of malabsorption

Electron beam irradiation facility for low to high dose irradiation applications

International Nuclear Information System (INIS)

Petwal, V.C.; Wanmode, Yashwant; Verma, Vijay Pal; Bhisikar, Abhay; Dwivedi, Jishnu; Shrivastava, P.; Gupta, P.D.

2013-01-01

Electron beam based irradiation facilities are becoming more and more popular over the conventional irradiator facilities due to many inherent advantages such as tunability of beam energy, availability of radiation both in electron mode and X-ray mode, wide range of the dose rate, control of radiation from a ON-OFF switch and other safety related merits. A prototype experimental facility based on electron accelerator has been set-up at RRCAT to meet the low-dose, medium dose and high-dose requirements for radiation processing of food, agricultural and medical products. The facility can be operated in the energy range from 7-10 MeV at variable power level from 0.05-3 kW to meet the dose rate requirement of 100 Gy to kGy. The facility is also equipped with a Bremsstrahlung converter optimized for X-ray irradiation at 7.5 MV. Availability of dose delivery in wide range with precision control and measurement has made the facility an excellent tool for researchers interested in electron/X-ray beam irradiation. A precision dosimetry lab based on alanine EPR and radiochromic film dosimetry system have been established to characterize the radiation field and precise dose measurements. Electron beam scattering technique has been developed to achieve low dose requirement for EB irradiation of various seeds such as groundnut, wheat, soybeans, moong beans, black gram etc. for mutation related studies. This paper describes various features of the facility together with the dosimetric measurements carried out for qualification of the facility and recent irradiation experiments carried out using this facility. (author)

MR appearance of pelvic hemangiopericytoma

International Nuclear Information System (INIS)

Kehagias, D.; Gouliamos, A.; Vlahos, L.

1999-01-01

A case of pelvic hemangiopericytoma in a 59-year-old woman is reported. The MR imaging features are presented. The tumor was unresectable and the patient received postoperative irradiation of 4200 cGy on the pelvis. One year after diagnosis, metastasis to a lumbar vertebra was discovered and additional irradiation of 3900 cGy was applied. One year later, CT showed control of the pelvic tumor and its metastasis. (orig.) (orig.)

Risk factors related to interfractional variation in whole pelvic irradiation for locally advanced pelvic malignancies

International Nuclear Information System (INIS)

Yoon, W.S.; Yang, D.S.; Lee, J.A.; Lee, S.; Park, Y.J.; Kim, C.Y.

2012-01-01

Purpose: The goal of the present study was to demonstrate risk factors affecting the interfractional variation in whole pelvic irradiation. Patients and methods: Daily image acquisitions of 101 patients with locally advanced pelvic malignancy were undertaken using a kilo-voltage orthogonal on-board imager. The baseline deviation (the shift between the initial treatment and each fraction; Value Base ) and day-to-day variation (the shift between the previous treatment and each fraction; Value DD ) were measured. The standard deviations (SD) along the x- (right-left), y- (cranial-caudal), and z- (anterior-posterior) axes (SD[x], SD[y], and SD[z], respectively), the 3D vector of the SD (SD[3D]), and the mean of 3D shift (mean[3D]) were calculated in each patient. Various clinical factors, lumbar pelvic balance and rotation, and the shift of 5 consecutive fractions from the initial treatment (Value 5Fx ) were investigated as risk factors. Results: The prone set-up showed a larger mean Base [3D] than in the supine position (p =0.063). A body mass index (BMI) ≥ 30 kg/m 2 resulted in the largest mean DD [3D] (p = 0.078) and SD DD [3D] (p = 0.058). All the SD 5Fx along the x-, y-, and z-axes had moderate linear relationships with SD Base and SD DD (p 5Fx [3D] also had a moderate linear relationship with the mean Base [3D], mean DD [3D], SD Base [3D], and SD DD [3D] (p 5Fx had the same significant relationship with SD Base and SD DD (p 2 was associated with the largest SD DD [x] (p = 0.003). Conclusion: Close surveillance through high-quality and frequent image guidance is recommended for patients with extensive variations of the initial five consecutive fractions or obesity. (orig.)

Options for radiation dose optimisation in pelvic digital radiography: A phantom study

International Nuclear Information System (INIS)

Manning-Stanley, Anthony S.; Ward, Anthony J.; England, Andrew

2012-01-01

Purpose: To investigate the effects of phantom orientation and AEC chamber selection on radiation dose and image quality (IQ) for digital radiography (DR) examinations of the pelvis. Methods: A phantom study was conducted using a DR detector, utilising all AEC chamber combinations. Current recommended orientation (Cr-AEC) was with the outer AEC chambers cranially orientated. mAs (given), source-to-skin distance and kV p data facilitated entrance surface dose and effective dose calculations. Six anatomical areas were blindly graded by two observers (3-point scale) for IQ. Statistical differences in radiation dose were determined using the paired Student’s t-test. IQ data was analysed for inter-observer variability (ICC) and statistical differences (Wilcoxon test). Results: Switching phantom orientation (caudally orientated outer AEC chambers: Ca-AEC) reduced mean radiation dose by 36.8%, (p < 0.001). A minor reduction in median IQ (15.5 vs. 15) was seen (p < 0.001). One Ca-AEC orientated image (1.6%) had all anatomical areas graded ‘inadequate’ by at least one observer; all other images were considered ‘adequate’ for all areas. In the Ca-AEC orientation, at least a 44% dose reduction was achievable (p < 0.001) when only the outer AEC chambers were used. In the Cr-AEC orientation, at least 11% dose reduction was achieved (p < 0.001); here the central chamber was used alone, or in combination. IQ scores fell, but remained ‘adequate’. Conclusion: Switching pelvic orientation relative to AEC chamber position can optimise radiation dose during pelvic radiography. AEC chamber position should be clearly marked on equipment to facilitate this. AEC selection should be an active process.

Low dose irradiation facilitates hepatocellular carcinoma genesis involving HULC.

Science.gov (United States)

Li, Yuan; Ge, Chang; Feng, Guoxing; Xiao, Huiwen; Dong, Jiali; Zhu, Changchun; Jiang, Mian; Cui, Ming; Fan, Saijun

2018-03-24

Irradiation exposure positive correlates with tumor formation, such as breast cancer and lung cancer. However, whether low dose irradiation induces hepatocarcinogenesis and the underlying mechanism remain poorly defined. In the present study, we reported that low dose irradiation facilitated the proliferation of hepatocyte through up-regulating HULC in vitro and in vivo. Low dose irradiation exposure elevated HULC expression level in hepatocyte. Deletion of heightened HULC erased the cells growth accelerated following low dose irradiation exposure. CDKN1, the neighbor gene of HULC, was down-regulated by overexpression of HULC following low dose irradiation exposure via complementary base pairing, resulting in promoting cell cycle process. Thus, our findings provide new insights into the mechanism of low dose irradiation-induced hepatocarcinogenesis through HULC/CDKN1 signaling, and shed light on the potential risk of low dose irradiation for the development of hepatocellular carcinoma in pre-clinical settings. © 2018 Wiley Periodicals, Inc.

A study on mice exposure dose for low-dose gamma-irradiation using glass dosimeter

Energy Technology Data Exchange (ETDEWEB)

Noh, Sung Jin; Kim, Hyo Jin; Kim, Hyun; Jeong, Dong Hyeok; Son, Tae Gen; Kim, Jung Ki; Yang, Kwang Mo; Kang, Yeong Rok [Research Center, Dongnam Institute of Radiological and Medical Sciences, Busan (Korea, Republic of); Nam, Sang Hee [Dept. of Biomedical Engineering, Inje University, Gimhae (Korea, Republic of)

2015-12-15

The low dose radiation is done for a long period, thus researchers have to know the exact dose distribution for the irradiated mouse. This research has been conducted in order to find out methods in transmitting an exact dose to mouse in a mouse irradiation experiment carried out using {sup 137}C{sub s} irradiation equipment installed in the DIRAMS (Dongnam Institution of Radiological and Medical Sciences) research center. We developed a single mouse housing cage and shelf with adjustable geometric factors such as distance and angle from collimator. The measurement of irradiated dose showed a maximal 42% difference of absorbed dose from the desired dose in the conventional irradiation system, whereas only 6% difference of the absorbed dose was measured in the self-developed mouse apartment system. In addition, multi mice housing showed much difference of the absorbed dose in between head and body, compared to single mouse housing in the conventional irradiation system. This research may allow further research about biological effect assessment for the low dose irradiation using the self-developed mouse apartment to provide more exact doses which it tries to transmit, and to have more reliability for the biological analysis results.

Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy.

Science.gov (United States)

Waugh, R; McCallum, H M; McCarty, M; Montgomery, R; Aszkenasy, M

2001-05-01

An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83%, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving.

The Dose-Volume Relationship of Small Bowel Irradiation and Acute Grade 3 Diarrhea During Chemoradiotherapy for Rectal Cancer

International Nuclear Information System (INIS)

Robertson, John M.; Lockman, David; Yan Di; Wallace, Michelle

2008-01-01

Purpose: Previous work has found a highly significant relationship between the irradiated small-bowel volume and development of Grade 3 small-bowel toxicity in patients with rectal cancer. This study tested the previously defined parameters in a much larger group of patients. Methods and Materials: A total of 96 consecutive patients receiving pelvic radiation therapy for rectal cancer had treatment planning computed tomographic scans with small-bowel contrast that allowed the small bowel to be outlined with calculation of a small-bowel dose-volume histogram for the initial intended pelvic treatment to 45 Gy. Patients with at least one parameter above the previously determined dose-volume parameters were considered high risk, whereas those with all parameters below these levels were low risk. The grade of diarrhea and presence of liquid stool was determined prospectively. Results: There was a highly significant association with small-bowel dose-volume and Grade 3 diarrhea (p ≤ 0.008). The high-risk and low-risk parameters were predictive with Grade 3 diarrhea in 16 of 51 high-risk patients and in 4 of 45 low-risk patients (p = 0.01). Patients who had undergone irradiation preoperatively had a lower incidence of Grade 3 diarrhea than those treated postoperatively (18% vs. 28%; p = 0.31); however, the predictive ability of the high-risk/low-risk parameters was better for preoperatively (p = 0.03) than for postoperatively treated patients (p = 0.15). Revised risk parameters were derived that improved the overall predictive ability (p = 0.004). Conclusions: The highly significant dose-volume relationship and validity of the high-risk and low-risk parameters were confirmed in a large group of patients. The risk parameters provided better modeling for the preoperative patients than for the postoperative patients

Dose rate effect in food irradiation

International Nuclear Information System (INIS)

Singh, H.

1991-08-01

It has been suggested that the minor losses of nutrients associated with radiation processing may be further reduced by irradiating foods at the high dose rates generally associated with electron beams from accelerators, rather than at the low dose rates typical of gamma irradiation (e.g. 60 Co). This review briefly examines available comparative data on gamma and electron irradiation of foods to evaluate these suggestions. (137 refs., 27 tabs., 11 figs.)

Evaluation of automatic exposure control system chamber for the dose optimization when examining pelvic in digital radiography.

Science.gov (United States)

Kim, Sung-Chul; Lee, Hae-Kag; Lee, Yang-Sub; Cho, Jae-Hwan

2015-01-01

We found a way to optimize the image quality and reduce the exposure dose of patients through the proper activity combination of the automatic exposure control system chamber for the dose optimization when examining the pelvic anteroposterior side using the phantom of the human body standard model. We set 7 combinations of the chamber of automatic exposure control system. The effective dose was yielded by measuring five times for each according to the activity combination of the chamber for the dose measurement. Five radiologists with more than five years of experience evaluated the image through picture archiving and communication system using double blind test while classifying the 6 anatomical sites into 3-point level (improper, proper, perfect). When only one central chamber was activated, the effective dose was found to be the highest level, 0.287 mSv; and lowest when only the top left chamber was used, 0.165 mSv. After the subjective evaluation by five panel members on the pelvic image was completed, there was no statistically meaningful difference between the 7 chamber combinations, and all had good image quality. When testing the pelvic anteroposterior side with digital radiography, we were able to reduce the exposure dose of patients using the combination of the top right side of or the top two of the chamber.

Split-Course, High-Dose Palliative Pelvic Radiotherapy for Locally Progressive Hormone-Refractory Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Gogna, Nirdosh Kumar, E-mail: kumar_gogna@health.qld.gov.au [Radiation Oncology Services, Mater Centre, Brisbane, Queensland (Australia); Baxi, Siddhartha; Hickey, Brigid; Baumann, Kathryn [Radiation Oncology Services, Mater Centre, Brisbane, Queensland (Australia); Burmeister, Elizabeth [Princess Alexandra Hospital, Brisbane, Queensland (Australia); Holt, Tanya [Radiation Oncology Services, Mater Centre, Brisbane, Queensland (Australia)

2012-06-01

Purpose: Local progression, in patients with hormone-refractory prostate cancer, often causes significant morbidity. Pelvic radiotherapy (RT) provides effective palliation in this setting, with most published studies supporting the use of high-dose regimens. The aim of the present study was to examine the role of split-course hypofractionated RT used at our institution in treating this group of patients. Methods and Materials: A total of 34 men with locoregionally progressive hormone-refractory prostate cancer, treated with a split course of pelvic RT (45-60 Gy in 18-24 fractions) between 2000 and 2008 were analyzed. The primary endpoints were the response rate and actuarial locoregional progression-free survival. Secondary endpoints included overall survival, compliance, and acute and late toxicity. Results: The median age was 71 years (range, 53-88). Treatment resulted in an overall initial response rate of 91%, a median locoregional progression-free survival of 43 months, and median overall survival of 28 months. Compliance was excellent and no significant late toxicity was reported. Conclusions: The split course pelvic RT described has an acceptable toxicity profile, is effective, and compares well with other high-dose palliative regimens that have been previously reported.

MR appearance of pelvic hemangiopericytoma

Energy Technology Data Exchange (ETDEWEB)

Kehagias, D.; Gouliamos, A.; Vlahos, L. [Dept. of Radiology, University of Athens (Greece)

1999-02-01

A case of pelvic hemangiopericytoma in a 59-year-old woman is reported. The MR imaging features are presented. The tumor was unresectable and the patient received postoperative irradiation of 4200 cGy on the pelvis. One year after diagnosis, metastasis to a lumbar vertebra was discovered and additional irradiation of 3900 cGy was applied. One year later, CT showed control of the pelvic tumor and its metastasis. (orig.) (orig.) With 3 figs., 10 refs.

Dose rate distribution for products irradiated in a semi-industrial irradiation plant. 1st stage

International Nuclear Information System (INIS)

Mangussi, J.

2005-01-01

The model of the bulk product absorbed dose rate distribution in a semi industrial irradiation plant is presented. In this plant the products are subject to a dynamic irradiation process: single-plaque, single-direction, four-passes. The additional two passes, also one on each side of the plaque, serve to minimize the lateral dose variation as well as the depth-dose non-uniformity. The first stage of this model takes only into account the direct absorbed dose rate; the model outputs are the depth-dose distribution and the lateral-dose distribution. The calculated absorbed dose in the bulk product and its uniformity-ratio after the dynamic irradiation process for different products is compared. The model results are in good agreement with the experimental measurements in a bulk of irradiated product; and the air absorbed dose rate in the irradiation chamber behind the product subject to the dynamic irradiation process. (author) [es

Parametric relationships for gamma dose and irradiation homogeneity in a sewage sludge irradiator

International Nuclear Information System (INIS)

Krishnamurthy, K.

1986-01-01

A study on the inter-relationships between factors governing γ dose and irradiation homogeneity in a sewage sludge irradiator is presented here. The analysis involves a 60 Co irradiator of cylindrical irradiation geometry with batchwise operation for hygienisation of liquid sludge. The influence of the parameters such as the source-target geometry, strength of 60 Co sources in the irradiator, hygienisation dose and rheological and hydraulic characteristics of sewage sludge on the selection of the three critical factors viz. the pumping rate (P) required to maintain turbulent flow regime in the irradiation zone; the mininum re-circulation time (Tsub(m)) essential to achieve a certain degree of homogeneity of dose absorption in the fluid; and the irradiation time (Tsub(i)) required to impart the necessary dose for the desired hygienisation effect in the sludge has been discussed in detail and inter-relationships among these three factors have been worked out. The applicability of the relationships to a typical operating plant has also been elucidated. (author)

Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy

Energy Technology Data Exchange (ETDEWEB)

Waugh, R.; McCarty, M. [Div. of Radiology, South Cleveland Hospital, South Tees Acute Hospitals NHS Trust, Marton Road, Middlesbrough, Cleveland (United Kingdom); McCallum, H.M. [Regional Medical Physics Dept., South Cleveland Hospital, Middlesbrough (United Kingdom); Montgomery, R. [Dept. of Orthopaedics, South Tees Hospitals NITS Trust, Middlesbrough (United Kingdom); Aszkenasy, M. [Tees and North East Yorkshire NHS Trust, West Lane Hospital, Middlesbrough (United Kingdom)

2001-05-01

Background. An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. Objective. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Materials and methods. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Results. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83 %, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Conclusion. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving. (orig.)

Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy

International Nuclear Information System (INIS)

Waugh, R.; McCarty, M.; McCallum, H.M.; Montgomery, R.; Aszkenasy, M.

2001-01-01

Background. An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique. Objective. A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography. Materials and methods. Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability. Results. Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83 %, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images. Conclusion. Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving. (orig.)

Daily low-dose/continuous capecitabine combined with neo-adjuvant irradiation reduces VEGF and PDGF-BB levels in rectal carcinoma patients

International Nuclear Information System (INIS)

Loven, David; B e'Ery, Einat; Yerushalmi, Rinat; Koren, Claude; Sulkes, Aaron; Fenig, Eyal; Lavi, Idit; Shaked, Yuval

2008-01-01

Metronomic low-dose chemotherapy regimen was found to have an antiangiogenic effect in tumors. However, its effect on levels of circulating pro-angiogenic and anti-angiogenic factors is not fully explored. Materials and methods. The levels of both VEGF and PDGF-BB were measured in three time points, in the serum of 32 rectal carcinoma patients receiving daily reduced-dose/continuous capecitabine in combination with preoperative pelvic irradiation. Results. We found a significant decrease in VEGF and PDGF-BB serum levels during the combination treatment (p<0.0001), followed by an increase in the successive rest-period (p<0.0001). In addition, substantial changes in platelets counts were observed during treatment in correlation with the changes of VEGF and PDGF-BB serum levels. Discussion. These results suggest that combined chemo-irradiation affect levels of pro-angiogenic factors during treatment, and may reflect an anti-angiogenic window induced during this treatment. The potential implications of this inducible phenomenon, including a possible clinical benefit from the administration of long lasting metronomic chemotherapy immediately following combined chemo-irradiation, would warrant further investigation

Irradiation doses on thyroid gland during the postoperative irradiation for breast cancer.

Science.gov (United States)

Akın, Mustafa; Ergen, Arzu; Unal, Aysegul; Bese, Nuran

2014-01-01

Thyroid gland is one of the radiosensitive endocrine organs in the body. It has been shown that direct irradiation of thyroid with total doses of 26 to 30 Gy can lead to functional abnormalities. In this study, irradiation doses on thyroid gland of the patients who received postoperative chest-wall/breast and regional nodal irradiation were assessed. Retrospective analyses of treatment plans from 122 breast cancer patients who were treated with 3D conformal radiotherapy (3D CRT) planning was performed. All patients received irradiation to supraclavicular/level III lymph nodes in addition to chest-wall/breast. A total dose of 46 Gy was delivered in 25 days to supraclavicular/level III lymph node region while a total dose of 50 Gy was delivered to whole breast/chest-wall. Thyroid gland was contoured on 2-5 mm thickness of computed tomography scans. Absolute thyroid volume, mean thyroid doses were calculated. The mean thyroid volume of all patients was 16.7 cc (min: 1.9 cc, max: 41.6 cc). The mean irradiation dose on was 22.5 Gy (0.32 Gy-46.5 Gy). The level of dose was higher than 26 Gy in 44% of the patients. In majority of the node-positive breast cancer patients treated with 3D CRT, the thyroid gland was exposed to considerable doses. On the other hand, for 44% of the patients are at risk for developing thyroid function abnormalities which should be considered during the routine follow-up.

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

International Nuclear Information System (INIS)

Turesson, I.

1990-01-01

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

Pentoxifylline in the treatment of radiation-related pelvic insufficiency fractures of bone

International Nuclear Information System (INIS)

Bese, N.S.; Oezgueroglu, M.; Kamberoglu, K.; Karahasanoglu, T.; Oeber, A.

2003-01-01

The reported incidence of bone complications after radiation therapy is quite low. The most commonly seen bone complication is insufficiency fractures of the pubis and sacrum. Treatment of insufficiency fractures consists of conservative care, and mineral replacement may be useful. The resolution of symptoms takes at least one year with these treatments. Vascular damage has an important role in the etiology of late radiation injury in normal tissues. Progressive ischemic changes further weaken the bone structure, which can cause fractures, and healing is also delayed. Pentoxifylline is a methylxanthine derivative that is shown to increase tissue blood flow. Here, we present a 63-year-old male patient with pelvic insufficiency fractures due to postoperative pelvic irradiation for rectal adenocarcinoma. The patient received pelvic radiotherapy to a total dose of 50.4 Gy with concomitant 5-FU. Six months after the completion of radiotherapy, the patient presented with severe pelvic pain. Pelvic magnetic resonance imaging (MRI) demonstrated abnormal signal intensity with insufficiency fractures at the sacrum and bone marrow edema near the fractures, but not an abnormal intensity that revealed bone metastases. Neither distant nor locoregional recurrence was observed at his work-up. The final diagnosis was insufficiency fractures of the pelvic bones owing to irradiation, and pentoxifylline (400 mg, 3 times daily, peroral, 1,200 mg/day) was used for eight months as treatment. Dramatic clinical improvement was obtained in six months, and objective healing was revealed with MRI. We concluded that pentoxifylline is a cost-effective drug with minimal adverse effects in treating radiation damage of bone. (author)

Dose-effect relationships for individual pelvic floor muscles and anorectal complaints after prostate radiotherapy.

NARCIS (Netherlands)

Smeenk, R.J.; Hoffmann, A.L.; Hopman, W.P.M.; Lin, E.N.J.T. van; Kaanders, J.H.A.M.

2012-01-01

PURPOSE: To delineate the individual pelvic floor muscles considered to be involved in anorectal toxicity and to investigate dose-effect relationships for fecal incontinence-related complaints after prostate radiotherapy (RT). METHODS AND MATERIALS: In 48 patients treated for localized prostate

Dose optimization in pelvic radiography by air gap method on CR and DR systems – A phantom study

International Nuclear Information System (INIS)

Chan, C.T.P.; Fung, K.K.L.

2015-01-01

Objectives: This study aimed at investigating the feasibility of replacing the anti-scatter grid with an air gap at a pelvic radiographic examination in order to reduce patient dose while retaining diagnostic image quality. Methods: An anthropomorphic pelvis phantom was placed on a device that allowed the adjustment of different air gap thicknesses introduced between the phantom and the image receptor of Computed Radiography (CR) and Digital Radiography (DR) systems. Grid and non-grid images with different air gap thicknesses of both systems were produced. Ovary and testes doses were measured using thermoluminescent dosimeters. Radiographic quality of all images was rated by 5 experienced radiographers blindly using the Image Quality Score (IQS) and Visual Grading Analysis (VGA) systems. Results: Images of diagnostic quality were produced while the grid was replaced by a range of 0–25 cm air gap thickness in the pelvic radiographic examination. At non-grid examination with 10 cm air gap thickness, a maximum of relative dose reduction by 70.7% and 81.6% at CR; 68.6% and 79.4% at DR were achieved respectively at ovary and testes locations of the phantom as compared with their corresponding grid examinations. Conclusion: 10 cm was found to be the optimal air gap thickness at the tested pelvic examination. Effective dose was found to be reduced by 2 and 2.3 times respectively at the CR and DR examinations while the anti-scatter grid was replaced by 10 cm air gap. However, dose reduction effect by air gap method was found to be more pronounced in CR than in DR. - Highlights: • 10 cm air gap was found to be a substitute to replace grid in pelvic RANDO in CR/DR. • Over 68.6% of dose reduction effect were achieved at the ovary and testes regions. • Over 76.4% of reduction in effective dose were achieved at both the tested regions. • Dose reduction by air gap method was found to be more pronounced in CR than in DR

Successful surrogate pregnancy after ovarian transposition, pelvic irradiation and hysterectomy.

Science.gov (United States)

Zinger, Michael; Liu, James H; Husseinzadeh, Nader; Thomas, Michael A

2004-07-01

Treatment of cervical cancer is often effective but at the cost of the woman's fertility. Ovarian transposition with subsequent oocyte retrieval and surrogate pregnancy can enable these patients to become genetic parents. We present the third reported such case. A 22-year-old woman was diagnosed with bulky, stage IB cervical cancer. Following transposition of both ovaries to the upper abdomen, she underwent pelvic irradiation followed by total abdominal hysterectomy. Eleven years later she presented for assisted reproduction. Two oocytes were retrieved following ovarian stimulation and transcutaneous, abdominal oocyte retrieval. One embryo was transferred to the gestational surrogate, resulting in a single intrauterine pregnancy and successful delivery at term. These procedures can preservefertility while successfully treating cervical cancer.

Conditioned instrumental behaviour in the rat: Effects of prenatal irradiation with various low dose-rate doses

International Nuclear Information System (INIS)

Klug, H.

1986-01-01

4 groups of rats of the Wistar-strain were subjected to γ-irradiation on the 16th day of gestation. 5 rats received 0,6 Gy low dose rate irradiation, 5 animals received 0,9 Gy low dose and 6 high dose irradiation, 3 females were shamirradiated. The male offspring of these 3 irradiation groups and 1 control group were tested for locomotor coordination on parallel bars and in a water maze. The female offspring were used in an operant conditioning test. The locomotor test showed slight impairment of locomotor coordination in those animals irradiated with 0,9 Gy high dose rate. Swimming ability was significantly impaired by irradiation with 0,9 Gy high dose rate. Performance in the operant conditioning task was improved by irradiation with 0,9 Gy both low and high dose rate. The 0,9 Gy high dose rate group learned faster than all the other groups. For the dose of 0,9 Gy a significant dose rate effect could be observed. For the dose of 0,6 Gy a similar tendency was observed, differences between 0,6 Gy high and low dose rate and controls not being significant. (orig./MG) [de

The irradiation effects and processing dose for pet foods decontamination

International Nuclear Information System (INIS)

Zhu Jiating; Feng Min; Liu Chunquan; Zhao Yongfu; Jin Yudong; Ji Ping; Ha Yiming; Gao Meixu; Li Shurong; Wang Feng; Zhou Hongjie

2009-01-01

The applied dose range of irradiation processing of 4 kinds of pet foods had been studied. More than 92% microorganisms was inactive at the irradiation dose of 4 kGy, while more than 99% was inactive at 6 kGy. The microorganism load of irradiated pet food by 8 kGy met the requirement of national standards. The 10 kGy irradiation could sterilize the treated pet food. Salmonella had not been checked in irradiated or unirradiated samples. When irradiation dose ranged 4-10 kGy, there was no significant difference on contents of moisture, fat, protein, coarse fiber, carbohydrates, minerals (not including Calcium) or amino acids between irradiated and un-irradiated pet food. There was also no significant change on sensory quality of irradiated samples within this dose range. It is concluded that the recommended irradiation processing dose range for pet foods is 4-10 kGy. (authors)

Bone marrow transplantation for girls with aplastic anemia utilizing modified field of total lymphoid irradiation and cyclophosphamide

International Nuclear Information System (INIS)

Hanada, Ryoji; Kawakami, Tetsuo; Akuta, Naoko; Moriwaki, Kohichi; Kato, Shizue; Inaba, Toshiya; Hayashi, Yasuhide; Yamamoto, Keiko

1990-01-01

A preparative regimen for allogeneic bone marrow transplantation, consisting of total lymphoid irradiation (TLI) with 750 cGy and cyclophosphamide (CY), was used in five girls with aplastic anemia. All patients received bone marrow from HLA matched/mixed lymphocyte culture negative siblings. In our regimen the 'inverted Y' field to irradiate the pelvic nodes was modified, which did not include the whole pelvic cavity in an attempt to protect the ovaries from irradiation. Although some of the pelvic nodes was supported not to be irradiated in order to protect the ovaries, engraftment occurred in all five patients including four who had been transfused prior to transplantation. All five are alive from 47 days to 1378 days (median 285 days) after transplantation without tranplantation-associated complications. The calculated dose to the ovaries was sixteen percent of the entire dose of the regimen. Both of the two evaluable patients that had received tranplantation just before or during the puberty are developing normal sex maturity including menstruation. This study suggests that our preparative regimen is effective not only for engraftment of the donor marrow but also for protecting the ovaries from irradiation. (author)

14C-lactose breath tests during pelvic radiotherapy: the effect of the amount of small bowel irradiated

International Nuclear Information System (INIS)

Weiss, R.G.; Stryker, J.A.

1982-01-01

Thirty patients who were undergoing pelvic radiotherapy had 14 C-lactose breath tests performed in the first and fifth weeks of treatment. In Group I (21 patients), a significant portion of the small intestine was irradiated, and in Group II (9 patients), only a small portion of the small intestine was irradiated. In Group I, the average reductions in the excretion of ingested 14 C between the first- and fifth-week tests were 41.5% at 1/2 hour postingestion (p less than 0.05), and 21.8% at 1 hour postingestion (p less than 0.05). In Group II, the percentage reductions were 11.8% and 3.7% at 1/2 and 1 hour, respectively (p greater than 0.05). The data suggest that lactose malabsorption is a factor in the etiology of the nausea, vomiting, and diarrhea experienced by patients who are undergoing pelvic radiotherapy, and that the amount of bowel included in the treatment volume significantly influences the degree of malabsorption

Dose distributions in electron irradiated plastic tubing

International Nuclear Information System (INIS)

Miller, A.; Pederson, W.B.

1981-01-01

Plastic tubes have been crosslinked by irradiation at a 10 MeV linear electron accelerator and at a 400 keV DC electron accelerator at different irradiation geometries. The diameter of the different tubes was 20, 33 and 110 millimeters. Dose distributions have been measured with thin radiochromic dye films, indicating that in all cases irradiation from two sides is a necessary and sufficient condition for obtaining a satisfactory dose distribution. (author)

Increased mortality by septicemia, interstitial pneumonitis and pulmonary fibrosis among bone marrow transplant recipients receiving an increased mean dose rate of total irradiation

International Nuclear Information System (INIS)

Ringden, O.; Baaryd, I.; Johansson, B.

1983-01-01

Seven bone marrow transplant recipients with acute lymphoblastic leukemia receiving a mean dose rate of 0.07 Gy/min of total body irradiation towards the pelvic midpoint and the lungs had an increased (p<0.01) overall death rate of 86 per cent compared with 33 per cent among 27 patients with acute non-lymphoblastic leukemia or acute lymphoblastic leukemia treated with a mean dose rate of 0.04 Gy/min. Among the patients receiving the higher dose rate there was an increased mortality in causes related to radiation toxicity like early septicemia, interstitial pneumonitis and pulmonary fibrosis, compared with all patients receiving the lower dose rate (p<0.01) and also with 10 patients from this group with acute lymphoblastic leukemia (p<0.02). (Auth.)

Dose levels from thoracic and pelvic examinations in two pediatric radiological departments in Norway - a comparison study of dose-area product and radiographic technique

International Nuclear Information System (INIS)

Kjernlie Saether, Hilde; Traegde Martinsen, Anne Catrine; Lagesen, Bente; Platou Holsen, Eva; Oevreboe, Kirsti Marie

2010-01-01

Background: Pediatric doses expressed in dose-area product (DAP) can be retrieved from only a few publications; most of which correlate DAP to patient size or large age spans. In clinical practice age is often the only available parameter describing the patient, and thus, evaluation of dose levels in pediatric radiology on the basis of DAP related to age alone would be useful in optimization work. Purpose: To provide comparable data on age-related DAP from thoracic and pelvic radiological examinations of children, and evaluate the usefulness of comparing age-related DAP and radiographic technique between systems to identify areas with potential for optimization. Material and Methods: DAP, age, and radiographic technique were registered for 575 thoracic examinations and 371 pelvic examinations of children from newborn up to 14 years of age in groups with an age span of 1 year, performed with two digital flat-panel systems and one computed radiography system. Results: DAP varies from 2.2 to 54.0 mGycm2 for thoracic examinations, and from 4.6 to 532.5 mGycm2 for pelvic examinations. There are significant differences in DAP between systems and departments due to differences in technique, equipment, and staff. Conclusion: This study provides comparable data on age-related DAP from thoracic and pelvic radiological examinations of children, which could be used as an input to estimate diagnostic reference levels. The comparison between systems of DAP and radiographic technique has proven useful in identifying areas where there may be a potential for optimization.

Dose controlled low energy electron irradiator for biomolecular films.

Science.gov (United States)

Kumar, S V K; Tare, Satej T; Upalekar, Yogesh V; Tsering, Thupten

2016-03-01

We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at -20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

Dose controlled low energy electron irradiator for biomolecular films

Energy Technology Data Exchange (ETDEWEB)

Kumar, S. V. K., E-mail: svkk@tifr.res.in; Tare, Satej T.; Upalekar, Yogesh V.; Tsering, Thupten [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India)

2016-03-15

We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at −20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

low dose irradiation growth in zirconium

International Nuclear Information System (INIS)

Fortis, A.M.

1987-01-01

Low dose neutron irradiation growth in textured and recrystallized zirconium, is studied, at the Candu Reactors Calandria temperature (340 K) and at 77 K. It was necessary to design and build 1: A facility to irradiate at high temperatures, which was installed in the Argentine Atomic Energy Commission's RA1 Reactor; 2: Devices to carry out thermal recoveries, and 3: Devices for 'in situ' measurements of dimensional changes. The first growth kinetics curves were obtained at 365 K and at 77 K in a cryostat under neutron fluxes of similar spectra. Irradiation growth experiments were made in zirconium doped with fissionable material (0,1 at % 235 U). In this way an equivalent dose two orders of magnitude greater than the reactor's fast neutrons dose was obtained, significantly reducing the irradiation time. The specimens used were bimetallic couples, thus obtaining a great accuracy in the measurements. The results allow to determine that the dislocation loops are the main cause of irradiation growth in recrystallized zirconium. Furthermore, it is shown the importance of 'in situ' measurements as a way to avoid the effect that temperature changes have in the final growth measurement; since they can modify the residual stresses and the overconcentrations of defects. (M.E.L.) [es

Role of prostate dose escalation in patients with greater than 15% risk of pelvic lymph node involvement

International Nuclear Information System (INIS)

Jacob, Rojymon; Hanlon, Alexandra L.; Horwitz, Eric M.; Movsas, Benjamin; Uzzo, Robert G.; Pollack, Alan

2005-01-01

Purpose: To determine whether the radiation dose is a determinant of clinical outcome in patients with a lymph node risk of >15% treated using whole pelvic (WP), partial pelvic (PP), or prostate only (PO) fields. Methods and materials: A total of 420 patients with prostate cancer treated with three-dimensional conformal radiotherapy with or without short-term androgen deprivation (STAD) between June 1989 and July 2000 were included in this study. Patients had an initial pretreatment prostate-specific antigen level of 15% in the patient population studied. These data suggest that the primary tumor takes precedence over lymph node coverage or the use of STAD. Doses >70 Gy are of paramount importance in such intermediate- and high-risk patients

A quality control study of the accuracy of patient positioning in irradiation of pelvic fields

International Nuclear Information System (INIS)

Creutzberg, Carien L.; Althof, Vincent G.M.; Hoog, Marjan de; Visser, Andries G.; Huizenga, Henk; Wijnmaalen, Arendjan; Levendag, Peter C.

1996-01-01

Purpose: Determining and improving the accuracy of patient positioning in pelvic fields. Methods and Materials: Small pelvic fields were studied in 16 patients treated for urological cancers using a three-field isocentric technique. Large pelvic fields were studied in 17 gynecological cancer patients treated with anterior and posterior (AP-PA) parallel opposed fields. Quantitative analysis of 645 megavolt images and comparison to 82 simulation images were carried out. Results: Small pelvic fields: for the position of the patient in the field, standard deviations of the difference between simulation (SIM) and treatment (MV) images were 3.4 mm in the lateral direction, 5.3 mm in the cranio-caudal direction, and 4.8 mm in the ventro-dorsal direction. Alterations in the positioning technique were made and tested. Large pelvic fields: differences between simulation and treatment images for the position of the patient in the field were 4 mm [1 standard deviation (SD)] in the lateral direction and 6.5 mm in the cranio-caudal direction. A systematic shift of the treatment field in the cranial direction had occurred in the majority of patients. A positioning technique using laser lines and marking of the caudal field border was shown to be more accurate. Conclusion: Studies of positioning accuracy in routine irradiation techniques are needed to obtain data for definition of the margins for each treatment site at each institution. Random variations should be kept at a minimum by monitoring and improving positioning techniques. Treatment verification by megavolt imaging or film should be used to detect and correct systematic variations early in the treatment series

Venous thromboembolism: Additional diagnostic value and radiation dose of pelvic CT venography in patients with suspected pulmonary embolism

International Nuclear Information System (INIS)

Reichert, Miriam; Henzler, Thomas; Krissak, Radko; Apfaltrer, Paul; Huck, Kurt; Buesing, Karen; Sueselbeck, Tim; Schoenberg, Stefan O.; Fink, Christian

2011-01-01

Purpose: To assess the additional diagnostic value of indirect CT venography (CTV) of the pelvis and upper thighs performed after pulmonary CT angiography (CTA) for the diagnosis of venous thromboembolism (VTE). Materials and methods: In a retrospective analysis, the radiology information system entries between January 2003 and December 2007 were searched for patients who received pulmonary CTA and additional CTV of the pelvis and upper thighs. Of those patients, the radiology reports were reviewed for the diagnosis of pulmonary embolism (PE) and deep venous thrombosis (DVT) in the pelvic veins and veins of the upper thighs. In cases with an isolated pelvic thrombosis at CTV (i.e. which only had a thrombosis in the pelvic veins but not in the veins of the upper thigh) ultrasound reports were reviewed for the presence of DVT of the legs. The estimated radiation dose was calculated for pulmonary CTA and for CTV of the pelvis. Results: In the defined period 3670 patients were referred to our institution for exclusion of PE. Of those, 642 patients (353 men, 289 women; mean age, 65 ± 15 years, age range 18-98 years) underwent combined pulmonary CTA and CTV. Among them, PE was found in 227 patients (35.4%). In patients without PE CTV was negative in all cases. In patients with PE, CTV demonstrated pelvic thrombosis in 24 patients (3.7%) and thrombosis of the upper thighs in 43 patients (6.6%). Of those patients 14 (2.1%) had DVT in the pelvis and upper thighs. In 10 patients (1.5%) CTV showed an isolated pelvic thrombosis. Of those patients ultrasound reports were available in 7 patients, which revealed DVT of the leg veins in 5 cases (1%). Thus, the estimated prevalence of isolated pelvic thrombosis detected only by pelvic CTV ranges between 1-5/642 patients (0.1-0.7%). Radiation dose ranges between 4.8 and 9.7 mSv for additional CTV of the pelvis. Conclusion: CTV of the pelvis performed after pulmonary CTA is of neglectable additional diagnostic value for the

Integral dose and evaluation of irradiated tissue volume

International Nuclear Information System (INIS)

Sivachenko, T.P.; Kalina, V.K.; Belous, A.K.; Gaevskij, V.I.

1984-01-01

Two parameters having potentialities of radiotherapy planning improvement are under consideration. One of these two parameters in an integral dose. An efficiency of application of special tables for integral dose estimation is noted. These tables were developed by the Kiev Physician Improvement Institute and the Cybernetics Institute of the Ukrainian SSR Academy of Science. The meaning of the term of ''irradiated tissue volume'' is specified, and the method of calculation of the irradiated tissue effective mass is considered. It is possible to evaluate with higher accuracy tolerance doses taking into account the irradiated mass

Risk factors related to interfractional variation in whole pelvic irradiation for locally advanced pelvic malignancies

Energy Technology Data Exchange (ETDEWEB)

Yoon, W.S.; Yang, D.S.; Lee, J.A.; Lee, S.; Park, Y.J.; Kim, C.Y. [Korea Univ. Medical Center, Seoul (Korea, Republic of). Dept. of Radiation Oncology

2012-05-15

Purpose: The goal of the present study was to demonstrate risk factors affecting the interfractional variation in whole pelvic irradiation. Patients and methods: Daily image acquisitions of 101 patients with locally advanced pelvic malignancy were undertaken using a kilo-voltage orthogonal on-board imager. The baseline deviation (the shift between the initial treatment and each fraction; Value{sub Base}) and day-to-day variation (the shift between the previous treatment and each fraction; Value{sub DD}) were measured. The standard deviations (SD) along the x- (right-left), y- (cranial-caudal), and z- (anterior-posterior) axes (SD[x], SD[y], and SD[z], respectively), the 3D vector of the SD (SD[3D]), and the mean of 3D shift (mean[3D]) were calculated in each patient. Various clinical factors, lumbar pelvic balance and rotation, and the shift of 5 consecutive fractions from the initial treatment (Value{sub 5Fx}) were investigated as risk factors. Results: The prone set-up showed a larger mean{sub Base}[3D] than in the supine position (p =0.063). A body mass index (BMI) {>=} 30 kg/m{sup 2} resulted in the largest mean{sub DD}[3D] (p = 0.078) and SD{sub DD}[3D] (p = 0.058). All the SD{sub 5Fx} along the x-, y-, and z-axes had moderate linear relationships with SD{sub Base} and SD{sub DD} (p < 0.001). The SD{sub 5Fx}[3D] also had a moderate linear relationship with the mean{sub Base}[3D], mean{sub DD}[3D], SD{sub Base}[3D], and SD{sub DD}[3D] (p < 0.001). In multivariate analysis, the SD{sub 5Fx} had the same significant relationship with SD{sub Base} and SD{sub DD} (p < 0.001). A BMI {>=} 30 kg/m{sup 2} was associated with the largest SD{sub DD}[x] (p = 0.003). Conclusion: Close surveillance through high-quality and frequent image guidance is recommended for patients with extensive variations of the initial five consecutive fractions or obesity. (orig.)

Dose-response of photographic emulsions under gamma irradiation

International Nuclear Information System (INIS)

Tran Dai Nghiep; Do Thi Nguyet Minh; Le Van Vinh

2003-01-01

Photographic emulsion is irradiated under gamma rays irradiation of 137 Cs in the IAEA/WHO secondary standard dosimetry laboratory. Dose-response of the film is established. The sensitivity of the film is determined. The dose-rate effect is studied. (author)

Preservation of Minced Meats by Using Medium and High-doses Irradiation

International Nuclear Information System (INIS)

Hammad, A.A.I.; Swailam, H.M.H.; Taha, S.M.A.

2003-01-01

The effect of medium (2.5-10 kGy) dose irradiation and high(20-70 kGy) dose irradiation on the microbiological, chemical and organoleptic properties of minced meat samples was studied. It was found that irradiation dose of only 5 kGy greatly reduced all microbial counts and completely eliminated all non-spore forming pathogenic bacteria contaminated minced meat samples. Consequently this irradiation dose extended the refrigerated (3 degree ±1) storage life of these products for more than 8 weeks. This irradiation dose almost did not affect the chemical composition, particularly the main amino acids and main fatty acids of minced meat samples. Panelists could not differentiate between irradiated minced meat samples at this dose and unirradiated samples. High doses irradiation, i.e.40 and 70 kGy were sufficient and efficient in sterilization of minced meat samples and in obtaining long-stable minced meat products (Two years) at ambient temperature. These irradiation doses slightly reduced (not more than 7%) aspartic acid, glutamic acid, methionine and lysine of minced meat. It also decreased the relative percentage of total unsaturated fatty acids by not more than 17 % . These high irradiation doses caused loss of C 18:3 and C 20:1

Dose measurement method suitable for management of food irradiation

International Nuclear Information System (INIS)

Tanaka, Ryuichi

1990-01-01

The report describes major features of dose measurement performed for the management of food irradiation processes, and dose measuring methods suitable for this purpose, and outlines some activities for establishing international standards for dose measurement. Traceability studies made recently are also reviewed. Compared with the sterilization of medical materials, food irradiation is different in some major points from a viewpoint of dose measurement: foods can undergo significant changes in bulk density, depending on its properties, during irradiation, and the variation in the uniformity of bulk density can be large within an irradiation unit and among different units. An accurate dosimeter and well-established traceability are essential for food irradiation control, and basically a dosimeter should be high in reproducibility and stable in dose response, and should be easy to readjust for eliminating systematic errors. A new type of dosimeter was developed recently, in which ESR is used to measure the free radicals generated by radiations in crystals of alanine, an amino acid. Standardization of large dose measurement procedures has been carried out by committee E10 set up under ASTM. (N.K.)

Dose Profiles in ECAL Crystals for Various Irradiation Conditions

CERN Document Server

Huhtinen, Mika

1998-01-01

Simulated dose profiles in various irradiation and beam test conditions are compared to the expected dose profiles in the ECAL crystals at LHC. Simple front or side irradiations with photons give too steep or too flat dose profiles, respectively. Thus, if dose maxima are fitted to agree, front irradiation underestimate the average dose whereas side irradiations tend to overestimate. Different profiles are difficult to compare reliably, but it seems likely that in both cases the discrepancy is about a factor of 2-3 but in different directions. For most purposes this is likely to be good enough, but should be taken into account in the interpretation of the test results. It is shown that using a customized lead mask between the source and the crystal can significantly improve the agreement between 60 Co side irradiations and the LHC predictions. A 400 MeV/c pion beam incident on a crystal matrix can also reproduce rather well the profiles expected in the barrel ECAL.

Seed irradiation with continuously increasing doses of thermal neutrons

International Nuclear Information System (INIS)

Uhlik, J.; Pfeifer, M.; Pittermann, P.

1977-01-01

In the 'Raman' pea cv. the biological activity of thermal neutrons was investigated after irradiation of a 780 mm column of seeds for 3000 and 4167 seconds with a flux of 5.607 x 10 9 n.cm -2 per second. For different fractions of the seed column the average density of the neutron flux was calculated. It was proved that for the described method of seed irradiation it was sufficient to determine only the dose approaching the lethal dose. If a sufficiently high column of seeds is used part of the column of seeds will be irradiated with the optimum range of doses. The advantages of the suggested method of irradiation are not only smaller time and technological requirements resulting from the need for the determination of only the critical lethal dose of radiation by means of inhibition tests performed with seedlings, but also a simpler irradiation procedure. The suggested method of irradiation is at least nine times cheaper. (author)

Inactive Doses and Protein Concentration of Gamma Irradiated Yersinia Enterocolitica

International Nuclear Information System (INIS)

Irawan Sugoro; Sandra Hermanto

2009-01-01

Yersinia enterocolitica is one of bacteria which cause coliform mastitis in dairy cows. The bacteria could be inactivated by gamma irradiation as inactivated vaccine candidate. The experiment has been conducted to determine the inactive doses and the protein concentration of Yersinia enterocolitica Y3 which has been irradiated by gamma rays. The cells cultures were irradiated by gamma rays with doses of 0, 100, 200, 400, 600, 800, 1.000 and 1.500 Gy (doses rate was 1089,59 Gy/hours). The inactive dose was determined by the drop test method and the protein concentration of cells were determined by Lowry method. The results showed that the inactive doses occurred on 800 – 1500 Gy. The different irradiation doses of cell cultures showed the effect of gamma irradiation on the protein concentration that was random and has a significant effect on the protein concentration. (author)

Intraoperative irradiation in advanced cervical cancer

International Nuclear Information System (INIS)

Delgado, G.; Goldson, A.L.; Ashayeri, E.; Petrilli, E.S.

1987-01-01

Conventional treatment of cervical cancer, such as radical hysterectomy with lymphadenectomy or pelvic exenteration, is limited to the pelvis. Standard radio-therapeutic treatment is a combination of external-beam radiotherapy to the pelvis and intracavitary applications. However, there is a group of patients for whom external radiotherapy alone has limitations. This group consists primarily of patients with large pelvic lymph nodes containing metastatic cancer, metastatically involved paraaortic lymph nodes outside the usual pelvic radiation field, or large central tumors with parametrial involvement. In patients with cancer of the cervix, the incidence of metastasis to paraaortic lymph nodes is high. Attempts to treat paraaortic nodes with external radiotherapy have resulted in high complication rates because the treatment field includes the highly sensitive gastrointestinal tract. External radiation therapy after retroperitoneal exploration of lymph nodes does not seem to improve survival. In an attempt to circumvent the morbidity and mortality associated with conventional external-beam irradiation, the authors initiated a pilot study of intraoperative electron-beam irradiation of the paraaortic nodes and of the large metastatic lymph nodes in the pelvis. The intraoperative boost was followed by conventional fractionated external-beam irradiation. The theoretical advantages of this procedure include a higher radiation tumor dose without a concomitant increase in treatment morbidity and mortality

Treatment of carcinoma of uterine cervix with high-dose-rate intracavitary irradiation using Ralstron

International Nuclear Information System (INIS)

Suh, C.O.; Kim, G.E.; Loh, J.J.K.

1988-01-01

From May 1979 through December 1981, a total of 530 patients with carcinoma of the uterine cervix were treated with radiation therapy with curative intent. Of the 530 patients, 365 were treated with a high-dose-rate remote-controlled afterloading system (RALS) using a cobalt source, and 165 patients received a low dose rate using a radium source. External pelvic irradiation with a total of 40-50 Gy to the whole pelvis followed by intracavitary radiation (ICR) with a total dose of 30-39 Gy in ten to 13 fractions to point A was the treatment protocol. ICR was given three times a week with a dose of 3 Gy per fraction. Five-year actuarial survival rate with high-dose-rate ICR by stage was as follows: stage I:82.7% (N = 19) stage II:69.6% (N = 184), and stage III:52.2% (N = 156). The above results were comparable with those with conventional low-dose-rate ICR treatment, and late complications were far less. The application of high-dose-rate ICR was technically simple and easily performed on an outpatient basis without anesthesia, and the patients tolerated it very well. Radiation exposure to personnel was virtually none as compared with that of low-dose-rate ICR. Within a given period of time, more patients can be treated with high-dose-rate ICR because of the short treatment time. The authors therefore conclude that high-dose-rate ICR is suitable for a cancer center where a large number of patients are to be treated

Low dose irradiation reduces cancer mortality rates

International Nuclear Information System (INIS)

Luckey, T.D.

2000-01-01

Low doses of ionizing radiation stimulate development, growth, memory, sensual acuity, fecundity, and immunity (Luckey, T.D., ''Radiation Hormesis'', CRC Press, 1991). Increased immune competence reduces cancer mortality rates and provides increased average lifespan in animals. Decreased cancer mortality rates in atom bomb victims who received low dose irradiation makes it desirable to examine populations exposed to low dose irradiation. Studies with over 300,000 workers and 7 million person-years provide a valid comparison of radiation exposed and control unclear workers (Luckey, T.D., Nurture with Ionizing Radiation, Nutrition and Cancer, 34:1-11, 1999). Careful selection of controls eliminated any ''healthy worker effect''. The person-year corrected average indicated the cancer mortality rate of exposed workers was only 51% that of control workers. Lung cancer mortality rates showed a highly significant negative correlation with radon concentrations in 272,000 U.S. homes (Cohen, B.L., Health Physics 68:157-174, 1995). In contrast, radon concentrations showed no effect on lung cancer rates in miners from different countries (Lubin, J.H. Am. J. Epidemiology 140:323-332, 1994). This provides evidence that excessive lung cancer in miners is caused by particulates (the major factor) or toxic gases. The relative risk for cancer mortality was 3.7% in 10,000 Taiwanese exposed to low level of radiation from 60 Co in their steel supported homes (Luan, Y.C. et al., Am. Nuclear Soc. Trans. Boston, 1999). This remarkable finding needs further study. A major mechanism for reduced cancer mortality rates is increased immune competence; this includes both cell and humoral components. Low dose irradiation increases circulating lymphocytes. Macrophage and ''natural killer'' cells can destroy altered (cancer) cells before the mass becomes too large. Low dose irradiation also kills suppressor T-cells; this allows helper T-cells to activate killer cells and antibody producing cells

Genetic efficiency of low-dose chronic irradiation in mammals and fish

International Nuclear Information System (INIS)

Goncharova, R.; Ryabokon, N.; Smolich, I.; Slukvin, A.

2001-01-01

The problem of biological effects of low-dose chronic irradiation is central radiobiological problem and seems to be very important for human monitoring and risk assessment Since 1986 we are engaged in studying genetic effects of low-dose chronic irradiation in natural populations of small mammals (bank vole - Clethrioiiomys glareolus) inhabiting radiocontaminated monitoring sites, in laboratory hybrid mice CBA*C57BI/6 j exposed to chronic irradiation at radiocontaminated sites, as well as in pond carp (Cyprinus carpio) reared in fish farms in areas contaminated due to the Chernobyl accident. The mean ground depositions in monitoring sites were 8-2330 kBq/m 2 and the mean bottom depositions in ponds were 52-3235 Bq/kg for Cs 137. We used conventional cytogenetics and genetics tests [1-3] and the following approaches in studying on genetic effects of low-dose chronic irradiation: Radiation exposures from external γ- and internal α, β, γ-irradiation from incorporated radionuclides were estimated for each specimen tested. Regression analysis of dose-effect relationships based on comparison of individual genetic end-points with individual absorbed doses was carried out We observed statistically significant changes in the frequencies of genetic end-points, which have been studied in somatic and germ cells, as well as in embryos of irradiated mammals and fish. So, the frequencies of chromosome aberrations in bank vole populations had up to 7-fold increase in comparison with background and pre-accident levels. It is of great importance to emphasize high radio-sensitivity of fertilized eggs (zygotes) and pond carp, embryos produced by chronically irradiated parents. Regression analysis allowed to reveal dependence of the studied parameters' frequencies on radiation exposure namely on the concentrations of basic dose forming radionuclides, absorbed dose rate and whole body absorbed dose. In most cases, dose-effect relationships were better approximated by non

Ameliorative effects of low dose/low dose-rate irradiation on reactive oxygen species-related diseases model mice

International Nuclear Information System (INIS)

Nomura, Takaharu

2008-01-01

Living organisms have developed complex biological system which protects themselves against environmental radiation, and irradiation with proper dose, dose-rate and irradiation time can stimulate their biological responses against oxidative stress evoked by the irradiation. Because reactive oxygen species are involved in various human diseases, non-toxic low dose/low dose-rate radiation can be utilized for the amelioration of such diseases. In this study, we used mouse experimental models for fatty liver, nephritis, diabetes, and ageing to elucidate the ameliorative effect of low dose/low dose-rate radiation in relation to endogenous antioxidant activity. Single irradiation at 0.5 Gy ameliorates carbon tetrachloride-induced fatty liver. The irradiation increases hepatic anti-oxidative system involving glutathione and glutathione peroxidase, suggesting that endogenous radical scavenger is essential for the ameliorative effect of low dose radiation on carbon tetrachloride-induced fatty liver. Single irradiation at 0.5 Gy ameliorates ferric nitrilotriacetate-induced nephritis. The irradiation increases catalase and decreases superoxide dismutase in kidney. The result suggests that low dose radiation reduced generation of hydroxide radical generation by reducing cellular hydroperoxide level. Single irradiation at 0.5 Gy at 12 week of age ameliorates incidence of type I diabetes in non-obese diabetic (NOD) mice through the suppression of inflammatory activity of splenocytes, and resultant apoptosis of β-cells in pancreas. The irradiation activities of superoxide dismutase and catalase, which coordinately diminish intracellular reactive oxygen species. Continuous irradiation at 0.70 mGy/hr from 10 week of age elongates life span, and suppresses alopecia in type II diabetesmice. The irradiation improved glucose clearance without affecting insulin-resistance, and increased pancreatic catalase activity. The results suggest that continuous low dose-rate irradiation protect

Dose-volume correlation in radiation-related late small-bowel complication

International Nuclear Information System (INIS)

Letschert, J.G.J.; Lebesque, J.V.; Boer, R.W. de; hart, A.A.M.; Barteling, H.

1990-01-01

The effects of the volume of irradiated small bowel on late small-bowel tolerance was studied, taking into account the equivalent total dose ant type of pre-irradiation surgical procedure. A method was developed to estimate small-bowel volumes in the high-bowel volumes were measured for three-field and AP-PA pelvic treatments (165 cm 3 and 400 cm 3 , respectively), extended AP-PA treatment of para-aortic and iliac nodes (1000 cm 3 ). In a retrospective study of 111 patientst irradiated after surgery for rectal or recto-sigmoid cancer to a dose of 45-50 Gy in 5 weeks, extended AP-PA pelvic treatment (n = 27) resulted in a high incidence of severe small-bowel complications (37%), whereas for limited (three-field) pelvic treatment (n = 84) the complication rate was 6%. These complication data together with data from the literature on postoperative radiation-related small-bowel complications were analysed using the maximum likelihood method to fit the data to the logistic form of the dose-response relation, taking the volume effect into account by a power law. The analysis indicated that the incidence of radiation-related small-bowel compllications was higher after rectal surgery than after other types of surgery, which might be explained by the development of more adhesions. For both types of surgery a volume exponent of the power-law of 0.26 ± 0.05 was established. This means that if the small-bowel volume is increased by a factor of 2, the total dose has to be reduced by 17% for the same incidence of small-bowel complications. (author). 45 refs.; 6 figs.; 4 tabs

High-dose irradiation: Wholesomeness of food irradiated with doses above 10 kGy. Report of a joint FAO/IAEA/WHO study group

International Nuclear Information System (INIS)

1999-01-01

This report presents the recommendations of an international group of experts convened by the World Health Organization, in association with the Food and Agriculture Organization of the United Nations and the International Atomic Energy Agency, to consider the implications of food irradiated to doses higher than those recommended in 1980 by the Joint Expert Committee on the Wholesomeness of Irradiated Food. Irradiation ensures the hygienic quality of food and extends shelf-life. The public perception of the safety of food irradiation has generally precluded its widespread use. However, current applications of food irradiation to doses over 10 kGy have been in the development of high-quality shelf-stable convenience foods for specific target groups such as immunosuppressed individuals and those under medical care, astronauts and outdoor enthusiasts. The Study Group reviewed data relating to the toxicological, nutritional, radiation chemical and physical aspects of food irradiated to doses above 10kGy from a wide range and number of studies carried out over the last forty years. This report presents a comprehensive summary, along with references, of the effectiveness and safety of the irradiation process. It concludes that foods treated with doses greater than 10kGy can be considered safe and nutritionally adequate when produced under established Good Manufacturing Practice

Normal tissue tolerance to external beam radiation therapy: Rectum; Dose de tolerance a l'irradiation des tissus sains: le rectum

Energy Technology Data Exchange (ETDEWEB)

Blanchard, P. [Departement de radiotherapie, institut Gustave-Roussy, 94 - Villejuif (France); Chapet, O. [Service d' oncologie-radiotherapie, centre hospitalier Lyon-Sud, 69 - Pierre-Benite (France)

2010-07-15

Radiation proctitis is among the most frequent radiation-induced toxicities. This is related to the high frequency of pelvic tumours and the key role of radiotherapy in the treatment of these tumours. Late rectal toxicity usually occurs within the first two years after the completion of a radiotherapy course. Rectal bleeding and a rectal syndrome are the main symptoms, and can be associated to fistulas or rectal ulcers. Clinical factors, such as diabetes mellitus, a severe acute radiation toxicity, small rectal volume or radiation hypersensitivity, are associated with late rectal toxicity. Dosimetric factors derived from the analysis of dose-volume histograms can also predict the occurrence of radiation proctitis, and help to adapt the prescribed dose and the ballistic of irradiation. (authors)

Dose and dose rate effects on coherent-to-incoherent transition of precipitates upon irradiation

Institute of Scientific and Technical Information of China (English)

LI Zhengchao

2006-01-01

A typical precipitation hardened alloy, Cu-Co dilute alloy was selected to study the precipitation behavior and irradiation effect on precipitates. It is found that the principal effect of ion irradiation on the coherent precipitates is loss of coherency, and TEM cross-section observations show that the fraction of the incoherent precipitates is dependent on dose but not on dose rate during heavy ion irradiation.

Immune reactivity after high-dose irradiation

International Nuclear Information System (INIS)

Gassmann, W.; Wottge, H.U.; von Kolzynski, M.; Mueller-Ruchholtz, W.

1986-01-01

Immune reactivity after total-body irradiation was investigated in rats using skin graft rejection as the indicator system. After sublethal irradiation with 10.5 Gy (approximately 50% lethality/6 weeks) the rejection of major histocompatibility complex allogeneic skin grafts was delayed significantly compared with nonirradiated control animals (28 versus 6.5 days). In contrast, skin grafts were rejected after 7.5 days in sublethally irradiated animals and 7 days in lethally irradiated animals if additional skin donor type alloantigens--namely, irradiated bone marrow cells--were given i.v. either simultaneously or with a delay of not more than 24 hr after the above conditioning regimen. These reactions were alloantigen-specific. They were observed in six different strain combinations with varying donors and recipients. Starting on day 2 after irradiation, i.v. injection of bone marrow gradually lost its effectivity and skin grafts were no longer rejected with uniform rapidity; skin donor marrow given on days 4 or 8 did not accelerate skin graft rejection at all. These data show that for approximately 1-2 days after high-dose total-body irradiation rats are still capable of starting a vigorous immune reaction against i.v.-injected alloantigens. The phenomenon of impaired rejection of skin grafted immediately after high-dose irradiation appears to result from the poor accessibility of skin graft alloantigens during the early postirradiation phase when vascularization of the grafted skin is insufficient

Mapping of nodal disease in locally advanced prostate cancer: Rethinking the clinical target volume for pelvic nodal irradiation based on vascular rather than bony anatomy

International Nuclear Information System (INIS)

Shih, Helen A.; Harisinghani, Mukesh; Zietman, Anthony L.; Wolfgang, John A.; Saksena, Mansi; Weissleder, Ralph

2005-01-01

Purpose: Toxicity from pelvic irradiation could be reduced if fields were limited to likely areas of nodal involvement rather than using the standard 'four-field box.' We employed a novel magnetic resonance lymphangiographic technique to highlight the likely sites of occult nodal metastasis from prostate cancer. Methods and Materials: Eighteen prostate cancer patients with pathologically confirmed node-positive disease had a total of 69 pathologic nodes identifiable by lymphotropic nanoparticle-enhanced MRI and semiquantitative nodal analysis. Fourteen of these nodes were in the para-aortic region, and 55 were in the pelvis. The position of each of these malignant nodes was mapped to a common template based on its relation to skeletal or vascular anatomy. Results: Relative to skeletal anatomy, nodes covered a diffuse volume from the mid lumbar spine to the superior pubic ramus and along the sacrum and pelvic side walls. In contrast, the nodal metastases mapped much more tightly relative to the large pelvic vessels. A proposed pelvic clinical target volume to encompass the region at greatest risk of containing occult nodal metastases would include a 2.0-cm radial expansion volume around the distal common iliac and proximal external and internal iliac vessels that would encompass 94.5% of the pelvic nodes at risk as defined by our node-positive prostate cancer patient cohort. Conclusions: Nodal metastases from prostate cancer are largely localized along the major pelvic vasculature. Defining nodal radiation treatment portals based on vascular rather than bony anatomy may allow for a significant decrease in normal pelvic tissue irradiation and its associated toxicities

Dose verification by OSLDs in the irradiation of cell cultures

International Nuclear Information System (INIS)

Meca C, E. A.; Bourel, V.; Notcovich, C.; Duran, H.

2015-10-01

The determination of value of irradiation dose presents difficulties when targets are irradiated located in regions where electronic equilibrium of charged particle is not reached, as in the case of irradiation -in vitro- of cell lines monolayer-cultured, in culture dishes or flasks covered with culture medium. The present study aimed to implement a methodology for dose verification in irradiation of cells in culture media by optically stimulated luminescence dosimetry (OSLD). For the determination of the absorbed dose in terms of cell proliferation OSL dosimeters of aluminum oxide doped with carbon (Al 2 O 3 :C) were used, which were calibrated to the irradiation conditions of culture medium and at doses that ranged from 0.1 to 15 Gy obtained with a linear accelerator of 6 MV photons. Intercomparison measurements were performed with an ionization chamber of 6 cm 3 . Different geometries were evaluated by varying the thicknesses of solid water, air and cell culture medium. The results showed deviations below 2.2% when compared with the obtained doses of OSLDs and planning system used. Also deviations were observed below 3.4% by eccentric points of the irradiation plane, finding homogeneous dose distribution. Uncertainty in the readings was less than 2%. The proposed methodology contributes a contribution in the dose verification in this type of irradiations, eliminating from the calculation uncertainties, potential errors in settling irradiation or possible equipment failure with which is radiating. It also provides certainty about the survival curves to be plotted with the experimental data. (Author)

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-07-01

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

Absorbed dose to mice in prolonged irradiation by low-dose rate ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Shiragai, Akihiro [National Inst. of Radiological Sciences, Chiba (Japan); Saitou, Mikio; Kudo, Iwao [and others

2000-07-01

In this paper, the dose absorbed by mice was evaluated as a preliminary study of the late effects of prolonged continuous irradiation of mice with low-dose rate ionizing radiation. Eight-week-old male and female SPF C3H/HeN mice in three irradiation rooms were exposed to irradiation at 8000, 400, and 20 mGy, respectively, using a {sup 137}Cs {gamma}-source. Nine racks were arranged in a circle approximately 2.5 m from the source in each room, and 10 cages were arranged on the 4 shelves of each rack. Dose distributions, such as in air at the source level, in the three rooms were estimated by using ionization chambers, and the absorbed dose distributions in the room and relative dose distributions in the cages in relation to the distance of the cage center were examined. The mean abdomen doses of the mice measured by TLD were compared with the absorbed doses in the cages. The absorbed dose distributions showed not only inverse-inverse-square-law behavior with distance from the source, but geometric symmetry in every room. The inherent scattering and absorption in each room are responsible for such behavior and asymmetry. Comparison of relative dose distributions revealed cage positions that are not suitable for experiments with high precision doses, but all positions can be used for prolonged continuous irradiation experiments if the position of the cages is rotated regularly. The mean abdomen doses of the mice were similar in each cage. The mean abdomen doses of the mice and the absorbed doses in a cage were almost the same in all cages. Except for errors concerning the positions of the racks and cages, the uncertainties in the exposure doses were estimated to be about {+-}12% for 8000 mGy group, 17% for 400 mGy group, and 35% for 20 mGy group. (K.H.)

Threshold irradiation dose for amorphization of silicon carbide

Energy Technology Data Exchange (ETDEWEB)

Snead, L.L.; Zinkle, S.J. [Oak Ridge National Lab., TN (United States)

1997-04-01

The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface of strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be {approximately}0.56 eV. This model successfully explains the difference in the temperature-dependent amorphization behavior of SiC irradiated with 0.56 MeV silicon ions at 1 x 10{sup {minus}3} dpa/s and with fission neutrons irradiated at 1 x 10{sup {minus}6} dpa/s irradiated to 15 dpa in the temperature range of {approximately}340 {+-} 10K.

Threshold irradiation dose for amorphization of silicon carbide

International Nuclear Information System (INIS)

Snead, L.L.; Zinkle, S.J.

1997-01-01

The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface of strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be ∼0.56 eV. This model successfully explains the difference in the temperature-dependent amorphization behavior of SiC irradiated with 0.56 MeV silicon ions at 1 x 10 -3 dpa/s and with fission neutrons irradiated at 1 x 10 -6 dpa/s irradiated to 15 dpa in the temperature range of ∼340 ± 10K

Threshold irradiation dose for amorphization of silicon carbide

International Nuclear Information System (INIS)

Snead, L.L.; Zinkle, S.J.

1997-01-01

The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be ∼0.56eV. This model successfully explains the difference in the temperature dependent amorphization behavior of SiC irradiated with 0.56 MeV Si + at 1 x 10 -3 dpa/s and with fission neutrons irradiated at 1 x 10 -6 dpa/s irradiated to 15 dpa in the temperature range of ∼340±10K

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

Science.gov (United States)

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

2002-06-01

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

Results of radiation therapy for uterine cervical cancer using high dose rate remote after loading system

International Nuclear Information System (INIS)

Ogawa, Yoshihiro; Nemoto, Kenji

2003-01-01

In Japan, radiotherapy with high dose rate remote after loading system (HDR-RALS) for intracavitary brachytherapy is the standard treatment for more than 30 years. This report showed the usefulness of HDR-RALS for uterine cervical cancer. From 1980 through 1999, 442 patients with uterine cervical cancers (stage I: 66, stage II: 161, stage III: 165, stage IV: 50) were treated. Radiotherapy was performed both external teletherapy and HDR-RALS. Overall survival rate at 5 years was 60.2%. The 5-year actuarial incidence of all complications was 16.4%. The 5-year actuarial incidence of all complications in cases treated with the sum doses of whole pelvic irradiation (without central shield) and RALS up to 49 Gy, 50 to 59 Gy or larger doses were 7.5%, 11.0% and 25.2%, respectively. Radiation therapy using HDR-RALS was very effective. While the dose of whole pelvic irradiation was increased, the actuarial incidence of all complications was increased. (author)

Post-irradiation stability of polyvinyl chloride at sterilizing doses

International Nuclear Information System (INIS)

Naimian, F.; Katbab, A.A.; Nazokdast, H.

1994-01-01

Post-irradiation stability of plasticized PVC irradiated by 60 Co gamma ray at sterilizing doses has been studied. Effects of irradiation upon chemical structure, mechanical properties and rheological behaviour of samples contained different amounts of Di(2-ethylhexyl)phthalate as plasticizer have been investigated. Formation of conjugated double bonds, carbonyl and hydroxyl groups have been followed by UV and FTIR spectrometers up to 6 months after irradiation. FTIR spectra of irradiated samples showed no significant changes in carbonyl and hydroxyl groups even 6 months after irradiation. However, changes in UV-visible spectra was observed for the irradiated samples up to 6 months post-irradiation. This has been attributed to the formation of polyenes which leads to the discoloration of this polymer. Despite a certain degree of discoloration, it appears that the mechanical properties of PVC are not affected by irradiation at sterilizing doses. No change in the melt viscosity of the irradiated PVC samples with post-irradiation was observed, which is inconsistent with the IR results. (author)

A retrospective study of the effects of pelvic irradiation for carcinoma of the cervix on gastrointestinal function

International Nuclear Information System (INIS)

Yeoh, E.; Ahmad, A.; Horowitz, M.; Russo, A.; Muecke, T.; Chatterton, B.; Robb, T.

1993-01-01

The purpose of the study was to evaluate the prevalence of disordered gastrointestinal function following therapeutic irradiation. Gastrointestinal function was evaluated in 30 randomly selected patients who had received pelvic irradiation for treatment of carcinoma of the cervix between 1 and 6 years previously. Each patient underwent evaluations of (a) gastrointestinal symptoms (b) absorption of bile acid, vitamin B12, lactose and fat (c) gastrointestinal transit: gastric emptying, small intestinal transit and whole gut transit and (d) intestinal permeability. Results were compared with those obtained in 18 normal volunteers. Stool frequency was above the control range in five patients and had increased (p < 0.001) since radiotherapy treatment. Bile acid (p<0.001) vitamin B12(p<0.01) and lactose (p<0.01) absorption were less in the patients when compared with the control subjects. Bile acid adsorption was below the control range in 14 of the 30 patients. Dietary calcium intake was lower (p<0.05) in those patients with lactose malabsorption. Gastric emptying (p<0.01) and small intestinal transit (p<0.01) were more rapid in the patients. Both small intestinal (r=-0.39, p<0.05) and whole gut (r=-0.45) transit were inversely related to stool frequency. Either bowel frequency, bile acid adsorption, vitamin B12 absorption was outside the control range in 19 of the 30 patients. Abnormal gastrointestinal function is essentially an inevitable long-term sequel of pelvic irradiation. 41 refs., 4 figs., 3 tabs

Stimulation of seeds by low dose irradiation

International Nuclear Information System (INIS)

Lawson, Helen

1976-05-01

The first section of the bibliography lists materials on the stimulation of seeds by low dose irradiation, with particular reference to stimulation of germination and yield. The second section contains a small number of selected references on seed irradiation facilities. (author)

Identification of irradiated foods prospects for post-irradiation estimate of irradiation dose in irradiated dry egg products

International Nuclear Information System (INIS)

Katusin-Raxem, B.; Mihaljievic, B.; Razem, D.

2002-01-01

Radiation-induced chemical changes in foods are generally very small at the usual processing doses. Some exception is radiation degradation of lipids, which are the components most susceptible to oxidation. A possible use of lipid hydroperoxides (LOOH) as indicators of irradiation is described for whole egg and egg yolk powders. A sensitive and reproducible spectrophotometric method for LOOH measurement based on feric thiocyanate, as modified in our laboratory, was applied. This method enabled the determination of LOOH, including oleic acid hydroperoxides, which is usually not possible with some other frequently used methods. The lowest limit of 0.05 mmol LOOH/kg lipid could be measured. The measurements were performed in various batches of whole egg and egg yolk powders by the same producer, as well as in samples supplied by various producers. Baseline level in unirradiated egg powder 0.110 ± 0.067 mmol LOOH /kgL was established. The formation of LOOH with dose, as well as the influence of age, irradiation conditions, storage time and storage conditions on LOOH were investigated. The irradiation of whole egg and egg yolk powders in the presence of air revealed an initially slow increase of LOOH, caused by an inherent antioxidative capacity, followed by a fast linear increase after the inhibition dose (D o ). In all investigated samples D o of 2 kGy was determined. Hydroperoxides produced in irradiated materials decay with time. In whole egg and egg yolk powders, after an initially fast decay, the level of LOOH continued to decrease by the first-order decay. Nevertheless, after a six months storage it was still possible to unambiguously identify samples which had been irradiated with 2 kGy in the presence of air. Reirradiation of these samples revealed a significant reduction of D o to 1 kGy. In samples irradiated with 4 kGy and kept under the same conditions, the shortening of D o to 0.5 kGy was determined by reirradiation. This offers a possibility for the

Influence of Routine MV CBCT Usage on Dose Distribution in Pelvic Radiotherapy

International Nuclear Information System (INIS)

Faj, D.; Kasabasic, M.; Ivkovic, A.; Tomas, I.; Jurkovic, S.

2013-01-01

The pelvic radiotherapy is a standard treatment for patients with cervical, uterine and rectal carcinomas. During radiation treatment open tabletop device or bellyboard is used to reduce the side effects of healthy surrounding tissue. Patients are continually adjusting to the bellyboard during the treatment which causes geometrical and dosage uncertainties and influences the results of the treatment. Therefore, to reduce these uncertainties, megavoltage cone-beam computed tomography (MV CBCT) system is used. The objective of this research was to evaluate the image acquisition dose delivered to patients from MV CBCT. MV CBCT imaging was simulated on 15 patients using 3D treatment planning software XiO (CMS Inc., St. Louis, MO). The influence of the routine MV CBCT usage on treatment plan was investigated by analyzing the changes in dose volume histograms, mean values and maximum doses in the planning volumes. Simulations have shown that daily usage of MV CBCT causes differences in the dose volume histograms. Moreover, for every patient mean value exceeded prescribed tolerance (±1% of the prescribed dose) and maximum value exceeded recommended maximum of 107% of the prescribed dose. The results have shown that MV CBCT dose to the patient should be a part of the RT plan.(author)

Fluorouracil and high-dose leucovorin with radiotherapy as adjuvant therapy for rectal cancer. Results of a phase II study

Energy Technology Data Exchange (ETDEWEB)

Giralt, J. [Radiation Oncology Service, Hospital General Universitari Vall d`Hebron, Barcelona (Spain); Rubio, D. [Medical Oncology Service, Hospital General Universitari Vall d`Hebron, Barcelona (Spain); Maldonado, X. [Radiation Oncology Service, Hospital General Universitari Vall d`Hebron, Barcelona (Spain); Naval, J. [Dept. of Surgery, Hospital General Universitari Vall d`Hebron, Barcelona (Spain); Casado, S. [Medical Oncology Service, Hospital General Universitari Vall d`Hebron, Barcelona (Spain); Lara, F. [Dept. of Surgery, Hospital General Universitari Vall d`Hebron, Barcelona (Spain); Rosello, J.M. [Dept. of Preventive Medicine, Hospital General Universitari Vall d`Hebron, Barcelona (Spain); Armengol, M. [Dept. of Surgery, Hospital General Universitari Vall d`Hebron, Barcelona (Spain)

1997-07-01

The purpose of this phase II study was to evaluate the efficacy and toxicity of fluorouracil and high-dose leucovorin (5-FU/LV) with pelvic irradiation as adjuvant therapy for patients with macroscopical resected rectal or recto-sigmoid cancer. Following surgery for stages II-III primary (52) or recurrent rectal cancer (4), 56 patients received 8 cycles of 5-FU/LV and pelvic irradiation. 5-FU doses were 200 mgr/m{sup 2} for cycles 2-3 and 300 mgr/m{sup 2} for cycles 1 and 4-8. LV doses remained fixed at 200 mgr/m{sup 2}. Pelvic radiation was started in the third week, between the first and second cycle. The total dose was 50.4 Gy. No serve complications had been recorded. The incidence of grade 3 diarrhea was 19%. Three patients presented leukopenia grade 3 (5%). In 44 patients (78%) the planned treatment could be administered. The median follow-up was 40 months (range 22-66). Seven patients had a local relapse (13%) and 6 developed distant metastasis (10%). The 3-year disease-free survival was 72% and the overall survival was 76%. These preliminary results show that combined post-operative 5-FU/LV and pelvic radiotherapy are well tolerated and present a reasonable local control and survival rates. This adjuvant treatment should be evaluated in randomized trials. (orig.).

Carcinoma of Uterine Cervix Treated with High Dose Rate Intracavitary Irradiation : 1. Patterns of Failure

International Nuclear Information System (INIS)

Kim, Ok Bae; Choi, Tae Jin; Kim, Jin Hee

1993-01-01

226 patients with carcinoma of the uterine cervix treated with curative radiation therapy at the Department of Therapeutic Radiology, Dongsan hospital, Keimyung university, School of medicine, from July, 1988 to May, 1991 were evaluated. The patients with all stages of the disease were included in this study. The maximum and mean follow up durations were 60 and 43 months. The radiation therapy consisted of external irradiation to the whole pelvis (2700 - 4500 cGy) and boost parametrial doses(for a total of 4500 - 6300 cGy) with midline shill(4x10 cm), and combined with intracavitary irradiation irradiation(5700 - 7500 cGy to point A). The distribution of patients according to the stage was as follows: stage IB 37(16.4%), stage IIA 91 (40.3%), Stage IIB 58(25.7%), stage III 32(13.8%), stage IV 8 (3.5%). The overall failure rate was 23.9%(54 patients). The failure rate increased as a function of stage from 13.5% in stage 1B to 15.4% in stage IIA, 25.9% in stage IIB, 46.9% in stage III, and 62.5% in stage IV. The pelvic failure alone were 32 patients and 11 patients were as a components of other failure, and remaining 11 patients had distant metastasis only. Among the 43 patients of locoregional failure, 28 patients were not controlled initially and in other words nearly half of total failures were due to residual tumor. The mean medial paracervical(point A) doses were 6700 cGy in stage IIB, 7200 cGy in stage IIA, 7450 cGy in stage IIB, 7600 cGy in stage III and 8100 cGy in stage IV. The medial paracevical doses showed some correlation with tumor control rate in early stage of disease (stage Ib, IIA), but there were higher central failure rate in advanced stage in spite of higher paracervical doses. In advanced stage, failure were not reduced by simple Increment of paracervical doses. To improve a locoregional control rate in advanced stages, it is necessary to give additional treatment such as concomitant chemoradiation

Technical relapsed testicular irradiation for acute lymphoblastic leukemia; Tecnica de irradiacion para testiculos en recidiva de leucemia linfoblastica aguda

Energy Technology Data Exchange (ETDEWEB)

Velazquez Miranda, S.; Delgado Gil, M. M.; Ortiz Siedel, M.; Munoz Carmona, D. M.; Gomez-Barcelona, J.

2011-07-01

Testicular irradiation in children suffering from acute lymphoblastic leukemia presents difficulties in relation to daily positioning, dosimetry for dose homogenization of complex geometry and volume change during irradiation thereof. This can lead to significant deviations from the prescribed doses. In addition, the usual techniques often associated with unnecessary irradiation of pelvic simphysis, anus and perineum. This, in the case of pediatric patients, is of great importance, since doses in the vicinity of 20 Gy are associated with a deviation of bone growth, low testosterone levels around 24 Gy and high rates of generation of second tumors. To overcome these problems we propose a special restraint in prone and non-coplanar irradiation.

Postirradiation changes in the pelvic wall

International Nuclear Information System (INIS)

Soevik, E.; Lien, H.H.; Tveit, K.M.

1993-01-01

MR images of 45 patients who had received radiation therapy for carcinoma of the anus or recurrent carcinoma of the rectum were reviewed with regard to postirradiation changes of the pelvic wall. High signal intensity in bone marrow on T1-weighted images due to fatty replacement was almost always observed. Presacral edema occurred in 7 of 36 patients who were examined 4 to 6 weeks after the end of irradiation and was more frequent at later studies. The pelvic wall muscles showed high signal intensity on T2-weighted images compatible with edema. This finding was most frequent on studies performed more than 6 weeks after the end of irradiation. The changes subsided more than a year after radiation therapy. To avoid an erroneous diagnosis of tumor infiltration into the pelvic wall, it is important to be familiar with the normal postirradiation changes of the presacral space and the muscles. (orig.)

Dose determination in irradiated chicken meat by ESR method

International Nuclear Information System (INIS)

Polat, M.

1996-01-01

In this work, the properties of the radicals produced in chicken bones have been investigated by ESR technique to determine the amount of dose applied to the chicken meats during the food irradiation. For this goal, the drumsticks from 6-8 weeks old chickens purchased from a local market were irradiated at dose levels of 0; 2; 4; 6; 8 and 10 kGy. Then, the ESR spectra of the powder samples prepared from the bones of the drumsticks have been investigated. Unirradiated chicken bones have been observed to show a weak ESR signal of single line character. CO-2 ionic radicals of axial symmetry with g=1.9973 and g=2.0025 were observed to be produced in irradiated samples which would give rise to a three peaks ESR spectrum. In addition, the signal intensities of the samples were found to depend linearly on the irradiation dose in the dose range of 0-10 kGy. The powder samples prepared from chicken leg bones cleaned from their meats and marrow and irradiated at dose levels of 1, 2, 3, 4, 5, 6, B, 10, 12,14, 16, 1B, 20 and 22 kGy were used to get the dose-response curve. It was found that this curve has biphasic character and that the dose yield was higher in the 12-1B kGy dose range and a decrease appears in this curve over 18 kGy. The radical produced in the bones were found to be the same whether the irradiation was performed after stripping the meat and removing the marrow from the bone or before the stripping. The ESR spectra of both irradiated and non irradiated samples were investigated in the temperature range of 100 K-450 K and changes in the ESR spectra of CO-2 radical have been studied. For non irradiated samples (controls). the signal intensities were found to decrease when the temperature was increased. The same investigation has been carried out for irradiated samples and it was concluded that the signal intensities relative to the peaks of the radical spectrum increase in the temperature range of 100 K-330 K, then they decrease over 330 K. The change in the

Pre-irradiation at a low dose-rate blunted p53 response

International Nuclear Information System (INIS)

Takahashi, A.; Ohnishi, K.; Asakawa, I.; Tamamoto, T.; Yasumoto, J.; Yuki, K.; Ohnishi, T.; Tachibana, A.

2003-01-01

Full text: We have studied whether the p53-centered signal transduction pathway induced by acute radiation is interfered with chronic pre-irradiation at a low dose-rate in human cultured cells and whole body of mice. In squamous cell carcinoma cells, we found that a challenge irradiation with X-ray immediately after chronic irradiation resulted in lower levels of p53 than those observed after the challenge irradiation alone. In addition, the induction of p53-centered apoptosis and the accumulation of its related proteins after the challenge irradiation were strongly correlated with the above-mentioned phenomena. In mouse spleen, the induction of apoptosis and the accumulation of p53 and Bax were observed dose-dependently at 12 h after a challenge irradiation. In contrast, we found significant suppression of them induced by challenge irradiation at a high dose-rate when mice were pre-irradiated with chronic irradiation at a low dose-rate. These findings suggest that chronic pre-irradiation suppressed the p53 function through radiation-induced p53-dependent signal transduction processes. There are numerous papers about p53 functions in apoptosis, radiosensitivity, genomic instability and cancer incidence in cultured cells or animals. According to our data and other findings, since p53 can prevent carcinogenesis, pre-irradiation at a low dose-rate might enhance the predisposition to cancer. Therefore, it is possible that different maximal permissible dose equivalents for the public populations are appropriate. Furthermore, concerning health of human beings, studies of the adaptive responses to radiation are quite important, because the radiation response strongly depends on experience of prior exposure to radiation

Panoramic irradiator dose mapping with pin photodiodes

International Nuclear Information System (INIS)

Ferreira, Danilo Cardenuto; Napolitano, Celia Marina; Bueno, Carmen Cecilia

2011-01-01

In this work we study the possibility of using commercial silicon PIN photodiodes (Siemens, SFH 00206) for dose mapping in the Panoramic Irradiator facility at IPEN-CNEN/SP. The chosen photodiode, that is encased in 1.2 mm thickness polymer layer, displays promising dosimetric characteristics such as small size (sensitive area of 7.00 mm 2 ), high sensitivity and low dark current (≅ 300 pA, at 0 V) together with low-cost and wide availability. The Panoramic facility is an irradiator Type II with absorbed dose certificated by International Dose Assurance Service (IDAS) offered by the International Agency Energy Atomic (IAEA). The charge registered by the diode as a function of the absorbed dose was in excellent agreement with that one calibrated by IDAS. Besides this, the easy handling and fast response of the SFH00206 diode compared to Fricke chemical dosimeters encouraged us to perform dose mapping around the source. (author)

Gamma irradiator dose mapping: a Monte Carlo simulation and experimental measurements

International Nuclear Information System (INIS)

Rodrigues, Rogerio R.; Ribeiro, Mariana A.; Grynberg, Suely E.; Ferreira, Andrea V.; Meira-Belo, Luiz Claudio; Sousa, Romulo V.; Sebastiao, Rita de C.O.

2009-01-01

Gamma irradiator facilities can be used in a wide range of applications such as biological and chemical researches, food treatment and sterilization of medical devices and products. Dose mapping must be performed in these equipment in order to establish plant operational parameters, as dose uniformity, source utilization efficiency and maximum and minimum dose positions. The isodoses curves are generally measured using dosimeters distributed throughout the device, and this procedure often consume a large amount of dosimeters, irradiation time and manpower. However, a detailed curve doses identification of the irradiation facility can be performed using Monte Carlo simulation, which reduces significantly the monitoring with dosimeters. The present work evaluates the absorbed dose in the CDTN/CNEN Gammacell Irradiation Facility, using the Monte Carlo N-particles (MCNP) code. The Gammacell 220, serial number 39, was produced by Atomic Energy of Canada Limited and was loaded with sources of 60 Co. Dose measurements using TLD and Fricke dosimeters were also performed to validate the calculations. The good agreement of the results shows that Monte Carlo simulations can be used as a predictive tool of irradiation planning for the CDTN/CNEN Gamma Cell Irradiator. (author)

Effects of “Danzhi Decoction” on Chronic Pelvic Pain, Hemodynamics, and Proinflammatory Factors in the Murine Model of Sequelae of Pelvic Inflammatory Disease

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Xiaoling Bu

2015-01-01

Full Text Available Objective. To evaluate the effect of Danzhi decoction (DZD on chronic pelvic pain (CPP, hemodynamics, and proinflammatory factors of sequelae of pelvic inflammatory diseases (SPID in murine model. Methods. SPID mice were randomly treated with high-dose DZD, mid-dose DZD, low-dose DZD, aspirin, and vehicle for 3 estrous circles. The Mouse Grimace Scale (MGS was performed to evaluate CPP; blood flows of the upper genital tract, pelvic wall, and mesentery were used to assess hemodynamics in SPID mice; expressions of vascular endothelial growth factor (VEGF, angiopoietin-2 (Ang-2, and osteopontin (OPN were measured by Western blot and immunochemistry. Results. Treatment with dose-dependent DZD significantly decreased the MGS scores, accelerated blood flows of the pelvis, and reduced expressions of VEGF, Ang-2, and OPN in the upper genital tract. Conclusions and Discussions. DZD was effective in relieving CPP and improving hemodynamics of the pelvic blood-stasis microenvironment in SPID mice. There was a relationship between CPP and the pelvic blood-stasis microenvironment. Furthermore, DZD might play a positive role in the anti-inflammatory process.

Age-dependent conversion coefficients for organ doses and effective doses for external neutron irradiation

International Nuclear Information System (INIS)

Nishizaki, Chihiro; Endo, Akira; Takahashi, Fumiaki

2006-06-01

To utilize dose assessment of the public for external neutron irradiation, conversion coefficients of absorbed doses of organs and effective doses were calculated using the numerical simulation technique for six different ages (adult, 15, 10, 5 and 1 years and newborn), which represent the member of the public. Calculations were performed using six age-specific anthropomorphic phantoms and a Monte Carlo radiation transport code for two irradiation geometries, anterior-posterior and rotational geometries, for 20 incident energies from thermal to 20 MeV. Effective doses defined by the 1990 Recommendation of ICRP were calculated from the absorbed doses in 21 organs. The calculated results were tabulated in the form of absorbed doses and effective doses per unit neutron fluence. The calculated conversion coefficients are used for dose assessment of the public around nuclear facilities and accelerator facilities. (author)

The effect of low-dose X-irradiation on immune system

International Nuclear Information System (INIS)

Ishii, Keiichiro

1996-01-01

The hypothesis of radiation hormesis has been proposed. To elucidate the hormetic effect on the immune system, we studied the mitogen-induced proliferation of splenocytes of F344/NSlc rat and BALB/c mouse after low-dose X-irradiation. Con A, PHA or LPS-induced proliferation of rat splenocytes prepared at 4 hr after irradiation was augmented with 5 cGy. This augmentation was observed within a few hours after irradiation, being a temporary effect. In case of mice, the proliferation of splenocytes induced by Con A, PHA or LPS was augmented by irradiation with 2.5 cGy. Thus, some phenomena of hormetic effect on the immune system were observed. However, the mechanism of augmentation of immune splenocytes is uncertainty. Therefore, we examined changes in production of LTB 4 and IL-1 being inflammatory mediators. After 5 cGy irradiation the production of LTB 4 of rat splenocyte showed a significant increase. Furthermore, 2.5 cGy irradiation also enhanced, the biological activity of intracellular IL-1 of LPS-stimulated mouse splenocytes. Additionally, to elucidate the stimulative effect on the antitumor immunity by low-dose X-irradiation, we studied the changes in the incidence of thymic lymphoma using AKR mice and of spontaneous metastasis to lung using tumor bearing mice. The incidence of thymic lymphoma was significantly decreased and the life span was significantly prolonged by periodical low-dose X-irradiation in terms of breeding of AKR mice. By an irradiation with 15 cGy, numbers of lung colony in the tumor bearing mice were decreased by 57% relative to the sham-irradiated controls. Then, IL-6 and TNF-α production of tumor bearing mice splenocytes were enhanced. These findings suggest that the low-dose X-irradiation might have caused a light inflammation and might have induced an augmentation of immune splenocytes. Furthermore, these results indicate that an augmentation of the antitumor immunity was induced by low-dose X-irradiation. (author). 127 refs

The effect of low-dose X-irradiation on immune system

Energy Technology Data Exchange (ETDEWEB)

Ishii, Keiichiro [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

1996-06-01

The hypothesis of radiation hormesis has been proposed. To elucidate the hormetic effect on the immune system, we studied the mitogen-induced proliferation of splenocytes of F344/NSlc rat and BALB/c mouse after low-dose X-irradiation. Con A, PHA or LPS-induced proliferation of rat splenocytes prepared at 4 hr after irradiation was augmented with 5 cGy. This augmentation was observed within a few hours after irradiation, being a temporary effect. In case of mice, the proliferation of splenocytes induced by Con A, PHA or LPS was augmented by irradiation with 2.5 cGy. Thus, some phenomena of hormetic effect on the immune system were observed. However, the mechanism of augmentation of immune splenocytes is uncertainty. Therefore, we examined changes in production of LTB{sub 4} and IL-1 being inflammatory mediators. After 5 cGy irradiation the production of LTB{sub 4} of rat splenocyte showed a significant increase. Furthermore, 2.5 cGy irradiation also enhanced, the biological activity of intracellular IL-1 of LPS-stimulated mouse splenocytes. Additionally, to elucidate the stimulative effect on the antitumor immunity by low-dose X-irradiation, we studied the changes in the incidence of thymic lymphoma using AKR mice and of spontaneous metastasis to lung using tumor bearing mice. The incidence of thymic lymphoma was significantly decreased and the life span was significantly prolonged by periodical low-dose X-irradiation in terms of breeding of AKR mice. By an irradiation with 15 cGy, numbers of lung colony in the tumor bearing mice were decreased by 57% relative to the sham-irradiated controls. Then, IL-6 and TNF-{alpha} production of tumor bearing mice splenocytes were enhanced. These findings suggest that the low-dose X-irradiation might have caused a light inflammation and might have induced an augmentation of immune splenocytes. Furthermore, these results indicate that an augmentation of the antitumor immunity was induced by low-dose X-irradiation. 127 refs.

ATM phosphorylation in HepG2 cells following continuous low dose-rate irradiation

International Nuclear Information System (INIS)

Mei Quelin; Du Duanming; Chen Zaizhong; Liu Pengcheng; Yang Jianyong; Li Yanhao

2008-01-01

Objective: To investigate the change of ATM phosphorylation in HepG2 cells following a continuous low dose-rate irradiation. Methods: Cells were persistently exposed to low dose-rate (8.28 cGy/h) irradiation. Indirect immunofluorescence and Western blot were used to detect the expression of ATM phosphorylated proteins. Colony forming assay was used to observe the effect of a low dose-rate irradiation on HepG2 cell survival. Results: After 30 min of low dose-rate irradiation, the phosphorylation of ATM occurred. After 6 h persistent irradiation, the expression of ATM phosphorylated protein reached the peak value, then gradually decreased. After ATM phosphorylation was inhibited with Wortmannin, the surviving fraction of HepG2 cells was lower than that of the irradiation alone group at each time point (P<0.05). Conclusions: Continuous low dose-rate irradiation attenuated ATM phosphorylation, suggesting that continuous low dose-rate irradiation has a potential effect for increasing the radiosensitivity of HepG2 cells. (authors)

Evaluation of absorbed doses during irradiation of patients

International Nuclear Information System (INIS)

Denisenko, O.N.; Kozlov, V.A.

1981-01-01

Provided is an analysis of a general scheme for the method of control over the dose field realization in the patient's body using direct dose measurements in patients. On the basis of data from literature presented are error limits in the stages of preradiation preparation and irradiation of patients, and in the stage of dose measurement for different irradiation techniques and radiation types. The authors also provide scientific data of their own. It has been concluded that the main emphasis should be placed on the improvement of topometry facilities, field calculation, patients posture and visual control methods of the radiation beam position [ru

Intraoperative irradiation for locally recurrent colorectal cancer in previously irradiated patients

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Haddock, M G; Gunderson, L L; Nelson, H; Cha, S; Devine, R M; Dozois, R R; Wolff, B G

1995-07-01

Purpose/Objective: Little information exists in the literature on salvage treatment for patients with pelvic recurrences of colorectal cancer who have previously received high dose radiation therapy (RT). A retrospective review of such patients treated aggressively with surgical resection and intraoperative electrons (IOERT) was undertaken. Material and Methods: From 1981 through 1994, 52 previously irradiated patients with recurrent locally advanced colorectal cancer without evidence of distant metastatic disease were treated with surgical resection and intraoperative electrons (IOERT) {+-} additional external beam RT. Every attempt was made to achieve a gross total resection prior to IOERT if it could be safely accomplished. IOERT doses ranged from 1000-3000 cGy with a median of 2000 cGy. 37 patients received additional external beam radiotherapy either pre- or post-operatively with doses ranging from 500-5040 cGy (median 2520 cGy). 20 patients received 5FU {+-} leukovorin during external beam RT. Three patients received 5FU+leukovorin after completion of RT. Results: 31 males and 21 females with a median age of 55 years (range 31-73 years) were treated. 71% of patients have been followed until death or for > 2 years. The median, 2-year and 5-year actuarial overall survival is 23 months, 48% and 13%, respectively. Actuarial central disease control (IOERT field) at 2 and 4 years is 72 and 57%; pelvic control at 2 and 4 years is 60 and 34%. Pelvic control rates are better in patients who received {>=} 3000 cGy external beam RT in addition to IOERT as compared to patients who received no external beam RT or < 3000 cGy, with 2 year pelvic control rates of 81% vs. 54%. 25 patients have developed distant metastases. The actuarial rate of appearance of distant metastatic disease at 2 and 4 years is 60 and 80%. Late complications attributable to IOERT include neuropathies in 13 patients (5 mild, 5 moderate, 3 severe) and narrowing or obstruction of the ureter in four

Intraoperative irradiation for locally recurrent colorectal cancer in previously irradiated patients

International Nuclear Information System (INIS)

Haddock, M.G.; Gunderson, L.L.; Nelson, H.; Cha, S.; Devine, R.M.; Dozois, R.R.; Wolff, B.G.

1995-01-01

Purpose/Objective: Little information exists in the literature on salvage treatment for patients with pelvic recurrences of colorectal cancer who have previously received high dose radiation therapy (RT). A retrospective review of such patients treated aggressively with surgical resection and intraoperative electrons (IOERT) was undertaken. Material and Methods: From 1981 through 1994, 52 previously irradiated patients with recurrent locally advanced colorectal cancer without evidence of distant metastatic disease were treated with surgical resection and intraoperative electrons (IOERT) ± additional external beam RT. Every attempt was made to achieve a gross total resection prior to IOERT if it could be safely accomplished. IOERT doses ranged from 1000-3000 cGy with a median of 2000 cGy. 37 patients received additional external beam radiotherapy either pre- or post-operatively with doses ranging from 500-5040 cGy (median 2520 cGy). 20 patients received 5FU ± leukovorin during external beam RT. Three patients received 5FU+leukovorin after completion of RT. Results: 31 males and 21 females with a median age of 55 years (range 31-73 years) were treated. 71% of patients have been followed until death or for > 2 years. The median, 2-year and 5-year actuarial overall survival is 23 months, 48% and 13%, respectively. Actuarial central disease control (IOERT field) at 2 and 4 years is 72 and 57%; pelvic control at 2 and 4 years is 60 and 34%. Pelvic control rates are better in patients who received ≥ 3000 cGy external beam RT in addition to IOERT as compared to patients who received no external beam RT or < 3000 cGy, with 2 year pelvic control rates of 81% vs. 54%. 25 patients have developed distant metastases. The actuarial rate of appearance of distant metastatic disease at 2 and 4 years is 60 and 80%. Late complications attributable to IOERT include neuropathies in 13 patients (5 mild, 5 moderate, 3 severe) and narrowing or obstruction of the ureter in four patients

Comparison of radiosensitization by 41 deg. C hyperthermia during low dose rate irradiation and during pulsed simulated low dose rate irradiation in human glioma cells

International Nuclear Information System (INIS)

Raaphorst, G. Peter; Ng, Cheng E.; Shahine, Bilal

1999-01-01

Purpose: Long duration mild hyperthermia has been shown to be an effective radiosensitizer when given concurrently with low dose rate irradiation. Pulsed simulated low dose rate (PSLDR) is now being used clinically, and we have set out to determine whether concurrent mild hyperthermia can be an effective radiosensitizer for the PSLDR protocol. Materials and Methods: Human glioma cells (U-87MG) were grown to plateau phase and treated in plateau phase in order to minimize cell cycle redistribution during protracted treatments. Low dose rate (LDR) irradiation and 41 deg. C hyperthermia were delivered by having a radium irradiator inside a temperature-controlled incubator. PSLDR was given using a 150 kVp X-ray unit and maintaining the cells at 41 deg. C between irradiations. The duration of irradiation and concurrent heating depended on total dose and extended up to 48 h. Results: When 41 deg. C hyperthermia was given currently with LDR or PSLDR, the thermal enhancement ratios (TER) were about the same if the average dose rate for PSLDR was the same as for LDR. At higher average dose rates for PSLDR the TERs became less. Conclusions: Our data show that concurrent mild hyperthermia can be an effective sensitizer for PSLDR. This sensitization can be as effective as for LDR if the same average dose rate is used and the TER increases with decreasing dose rate. Thus mild hyperthermia combined with PSLDR may be an effective clinical protocol

Effects of pelvic telecobalt irradiation on gonadotropin secretin

International Nuclear Information System (INIS)

Pfenninger, R.

1978-01-01

The pitnitary reaction in women operated according to Wertheim who had menstruated regularly was investigated during telecobalt irradiation. The pitnitary reaction was observed with the aid of the gonadotropin releasing factor. A dose of 25 mcg RH-LH was applied. Releasing factor examinations were carried out before exposure with functioning ovaries, after a dose of 2000 R (i.e., after 10 exposures), and after 6000 R. In the meantime, separate gonadotropin examinations were carried out continuously. A FSH reaction was observed already after 14 days, and the values were raised to almost menopause values. After this, the FSH increased further, while the LH reaction was not observed until much later. The investigation suggests an interrelation between follicle apparatus and FSH, oestrogens and LH. (orig./AJ) [de

Effect of pelvic irradiation of lactose absorption. [. gamma. rays or x rays were used in gynecologic malignancy therapy

Energy Technology Data Exchange (ETDEWEB)

Stryker, J.A.; Mortel, R.; Hepner, G.W.

1978-01-01

Twenty-four patients undergoing pelvic irradiation for gynecologic malignancies had /sup 14/C-lactose breath tests performed in the first and fifth weeks of their treatment. The /sup 14/C-lactose breath test was performed by administering 2 ..mu..Ci of /sup 14/C-lactose by mouth along with 50 g of lactose. Breath samples were collected in ethanolic hyamine 1, 2, and 3 hr later; the radioactivity of the trapped /sup 14/CO/sub 2/ was determined by liquid scintillation spectroscopy. In the first week of treatment the percentage of administered /sup 14/C excreted as /sup 14/CO/sub 2/ at 1, 2, and 3 hr was 1.7 +- 0.8% (mean +- SD), 4.5 +- 1.6%, and 5.8 +- 1.4%, respectively. In the fifth week of treatment the 1-hr, 2-hr, and 3-hr values were 1.2 +- 0.9%, 3.6 +- 2.0%, and 4.7 +- 1.9%, respectively. The difference between the first week and fifth week test results at 1, 2, and 3 hr was statistically significant (t = 2.64, p < 0.02), (t = 2.24, p < 0.05), (t = 2.95, p < 0.01). There was a negative correlation between the 1-hr /sup 14/C-lactose breath test results in the fifth week and the stool frequency at that time (r = -0.44, p < 0.05). Seven of 12 patients whose 1 hr /sup 14/C-lactose breath test results in the fifth week were below normal (<1.2%) had nausea at that time. The data suggest that in some patients, lactose malabsorption as a result of the effect of radiation on small intestinal function may be etiologically related to the symptoms of nausea and diarrhea which occur commonly in patients who are undergoing pelvic irradiation. In addition, the results suggest that lactose-containing foods should be restricted in some patients who are undergoing pelvic irradiation to prevent symptoms resulting from radiation-induced lactose intolerance.

Identification of irradiated meat using electron spin resonance (ESR) spectroscopy and estimation of applied dose using re-irradiation

International Nuclear Information System (INIS)

Chawla, S.P.; Thomas, Paul; Bongirwar, D.R.

2001-01-01

An in-house blind trail on bone-in meat chunks was carried out in which 35 coded samples were correctly identified. The samples were either left unirradiated or had been irradiated to dose of 1, 2.5 or 4 kGy. Using re-irradiation, the dose received by the samples were determined with either linear, quadratic or exponential equation. The quadratic or exponential equation gave more successful estimates of irradiation dose whereas linear fit equations tend to over estimate the dose. (author)

Low- and high-dose laser irradiation effects on cell migration and destruction

Science.gov (United States)

Layton, Elivia; Gallagher, Kyra A.; Zukerman, Sara; Stevens, Brianna; Zhou, Feifan; Liu, Hong; Chen, Wei R.

2018-02-01

Metastases are the cause of more than 90 percent of cancer-related deaths. Current treatment methods, including chemotherapy, radiation, and surgery, fail to target the metastases effectively. One potential treatment for metastatic cancer is laser immunotherapy (LIT). LIT combines the use of a photothermal laser with an immunoadjuvant, Glycated Chitosan (GC). GC combined with single-walled carbon nanotubes (SWNTs) has proven to be a viable alternative to traditional cancer treatment methods, when under irradiation of laser with appropriate wavelength. In this study, the effects of low dose and high dose laser irradiation on metastatic pancreatic cancer cell migration were observed. It was found that low dose irradiation increased the migration rate, but the high dose irradiation significantly decreased the migration rate of the cancer cells. When using LIT, the goal is to kill tumor cells and to prompt the correct immune response. If the tumor were irradiated with a low dose, it would promote metastasis. If the dose of irradiation were too high, it would destroy the entire tumor and the immune response would not recognize the tumor. Therefore, the laser dose plays an important role in LIT, particularly when using SWNT as light absorbing agent. Our results from this study will delineate the optimal laser irradiation dose for destroying tumor cells and at the same time preserve and release tumor antigens as a precursor of antitumor immune response.

Volume dose of organs at risk in the irradiated volume

International Nuclear Information System (INIS)

Hishikawa, Yoshio; Tanaka, Shinichi; Miura, Takashi

1984-01-01

Absorbed dose of organs at risk in the 50% irradiated volume needs to be carefully monitored because there is high risk of radiation injury. This paper reports on the histogram of threedimensional volume dose of organs at risk, which is obtained by computer calculation of CT scans. In order to obtain this histogram, CT is first performed in the irradiation field. The dose in each pixel is then examined by the computer as to each slice. After the pixels of all slices in the organ at risk of the irradiated field are classified according to the doses, the number of pixels in the same dose class is counted. The result is expressed in a histogram. The histogram can show the differences of influence to organs at risk given by various radiation treatment techniques. Total volume dose of organs at risk after radiotherapy can also be obtained by integration of each dose of different treatment techniques. (author)

Dose uniformity estimations in the blood irradiator

International Nuclear Information System (INIS)

George, J.R.

2002-01-01

Use of irradiated blood in transfusions is recognized as the most effective way of preventing Graft Versus Host Disease (GVHD). This paper shows the study carried out in the dose rate variation for various source arrangements for optimising the source-sample chamber geometry, during the development of the Blood Irradiator, Bl-2000

Dosimetric Study of Pelvic Proton Radiotherapy for High-Risk Prostate Cancer

International Nuclear Information System (INIS)

Chera, Bhishamjit S.; Vargas, Carlos; Morris, Christopher G.; Louis, Debbie; Flampouri, Stella; Yeung, Daniel; Duvvuri, Srividya; Li Zuofeng; Mendenhall, Nancy Price

2009-01-01

Purpose: To compare dose distributions in targeted tissues (prostate, seminal vesicles, pelvic regional nodes) and nontargeted tissues in the pelvis with intensity-modulated radiotherapy (IMRT) and forward-planned, double-scattered, three-dimensional proton radiotherapy (3D-PRT). Methods and Materials: IMRT, IMRT followed by a prostate 3D-PRT boost (IMRT/3D-PRT), and 3D-PRT plans were created for 5 high-risk prostate cancer patients (n = 15 plans). A 78-CGE/Gy dose was prescribed to the prostate and proximal seminal vesicles and a 46-CGE/Gy was prescribed to the pelvic nodes. Various dosimetric endpoints were compared. Results: Target coverage of the prostate and nodal planning target volumes was adequate for all three plans. Compared with the IMRT and IMRT/3D-PRT plans, the 3D-PRT plans reduced the mean dose to the rectum, rectal wall, bladder, bladder wall, small bowel, and pelvis. The relative benefit of 3D-PRT (vs IMRT) at reducing the rectum and rectal wall V5-V40 was 53% to 71% (p < 0.05). For the bladder and bladder wall, the relative benefit for V5 to V40 CGE/Gy was 40% to 63% (p < 0.05). The relative benefit for reducing the volume of small bowel irradiated from 5 to 30 CGE/Gy in the 3D-PRT ranged from 62% to 69% (p < 0.05). Use of 3D-PRT did not produce the typical low-dose 'bath' of radiation to the pelvis seen with IMRT. Femoral head doses were higher for the 3D-PRT. Conclusions: Use of 3D-PRT significantly reduced the dose to normal tissues in the pelvis while maintaining adequate target coverage compared with IMRT or IMRT/3D-PRT. When treating the prostate, seminal vesicles, and pelvic lymph nodes in prostate cancer, proton therapy may improve the therapeutic ratio beyond what is possible with IMRT.

Inhibition of alloxan diabetes by low dose γ-irradiation before alloxan administration

International Nuclear Information System (INIS)

Yamaoka, Kiyonori; Takehara, Yoshiki; Yoshioka, Tamotsu; Utsumi, Kozo.

1994-01-01

We evaluated the inhibitory effects of whole body 60 Co-γ irradiation at a single low dose on alloxan-induced hyperglycemia in rats. (1) In rats that received alloxan, SOD activity in pancreas significantly decreased, but the decrease was inhibited by irradiation at a dose of 0.5 Gy. (2) Similarly, plasma peroxide, pancreatic peroxide, and blood glucose increased. However, the increase in pancreatic peroxide was inhibited by irradiation at a dose of 0.5 or 1.0 Gy and the increase in blood glucose by irradiation at 0.5 Gy. (3) After alloxan administration, degranulation was observed in cells, but this was inhibited by irradiation at 0.5 Gy. These results suggest that alloxan diabetes was inhibited by the increase of SOD activity in pancreas after low dose irradiation at 0.5 Gy. (author)

Calcium carbonate as a possible dosimeter for high irradiation doses

International Nuclear Information System (INIS)

Negron M, A.; Ramos B, S.; Camargo R, C.; Uribe, R. M.; Gomez V, V.; Kobayashi, K.

2014-08-01

The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

Calcium carbonate as a possible dosimeter for high irradiation doses

Energy Technology Data Exchange (ETDEWEB)

Negron M, A.; Ramos B, S.; Camargo R, C. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Uribe, R. M. [Kent State University, College of Technology, Kent OH (United States); Gomez V, V. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Kobayashi, K., E-mail: negron@nucleares.unam.mx [Yokohama National University (Japan)

2014-08-15

The aim of this work is to analyze the interactions of 5 MeV electron beam radiation and a 290 MeV/u Carbon beam with calcium carbonate (powder) at 298 K and at different irradiation doses, for the potential use of calcium carbonate as a high-dose dosimeter. The irradiation doses with the electron beam were from 0.015 to 9 MGy, and with Carbon beam from 1.5 kGy to 8 kGy. High-energy radiation induces the formation of free radicals in solid calcium carbonate that can be detected and measured by electron paramagnetic resonance (EPR). An increase of the EPR response for some of the free radicals produced in the sample was observed as a function of the irradiation dose. The response of one of the radicals decreased with the dose. These measurements are reproducible; the preparation of the sample is simple and inexpensive; and the signal is stable for several months. The response curves show that the dosimeter tends to saturate at 10 MGy. Based on these properties, we propose this chemical compound as a high-dose dosimeter, mainly for electron irradiation. (author)

Estimation of dose in irradiated chicken bone by ESR method

International Nuclear Information System (INIS)

Tanabe, Hiroko; Hougetu, Daisuke

1998-01-01

The author studied the conditions needed to routinely estimate the radiation dose in chicken bone by repeated re-irradiation and measuring ESR signals. Chicken meat containing bone was γ-irradiated at doses of up to 3kGy, accepted as the commercially used dose. The results show that points in sample preparation and ESR measurement are as follows: Both ends of bone are cut off and central part of compact bone is used for experiment. To obtain accurate ESR spectrum, marrow should be scraped out completely. Sample bone fragments of 1-2mm particle size and ca.100mg are recommended to obtain stable and maximum signal. In practice, by re-irradiating up to 5kGy and extrapolating data of the signal intensity to zero using linear regression analysis, radiation dose is estimated. For example, in one experiment, estimated doses of chicken bones initially irradiated at 3.0kGy, 1.0kGy, 0.50kGy and 0.25kGy were 3.4kGy, 1.3kGy, 0.81kGy and 0.57kGy. (author)

Chromosomal Aberrations in Normal and AT Cells Exposed to High Dose of Low Dose Rate Irradiation

Science.gov (United States)

Kawata, T.; Shigematsu, N.; Kawaguchi, O.; Liu, C.; Furusawa, Y.; Hirayama, R.; George, K.; Cucinotta, F.

2011-01-01

Ataxia telangiectasia (A-T) is a human autosomally recessive syndrome characterized by cerebellar ataxia, telangiectases, immune dysfunction, and genomic instability, and high rate of cancer incidence. A-T cell lines are abnormally sensitive to agents that induce DNA double strand breaks, including ionizing radiation. The diverse clinical features in individuals affected by A-T and the complex cellular phenotypes are all linked to the functional inactivation of a single gene (AT mutated). It is well known that cells deficient in ATM show increased yields of both simple and complex chromosomal aberrations after high-dose-rate irradiation, but, less is known on how cells respond to low-dose-rate irradiation. It has been shown that AT cells contain a large number of unrejoined breaks after both low-dose-rate irradiation and high-dose-rate irradiation, however sensitivity for chromosomal aberrations at low-dose-rate are less often studied. To study how AT cells respond to low-dose-rate irradiation, we exposed confluent normal and AT fibroblast cells to up to 3 Gy of gamma-irradiation at a dose rate of 0.5 Gy/day and analyzed chromosomal aberrations in G0 using fusion PCC (Premature Chromosomal Condensation) technique. Giemsa staining showed that 1 Gy induces around 0.36 unrejoined fragments per cell in normal cells and around 1.35 fragments in AT cells, whereas 3Gy induces around 0.65 fragments in normal cells and around 3.3 fragments in AT cells. This result indicates that AT cells can rejoin breaks less effectively in G0 phase of the cell cycle? compared to normal cells. We also analyzed chromosomal exchanges in normal and AT cells after exposure to 3 Gy of low-dose-rate rays using a combination of G0 PCC and FISH techniques. Misrejoining was detected in the AT cells only? When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, the yield of unrejoined breaks decreased in both normal and AT

Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

International Nuclear Information System (INIS)

Shamma, M.; Al-Adawi, M.; Sharabi, N.

2002-11-01

The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays. (author)

Determination the lethal dose of ascaris lumbricoides ova by gamma irradiation

CERN Document Server

Shamma, M A; Sharabi, N

2002-01-01

The lethal gamma irradiation dose of ascaris lumbricoides which collected from Damascus Sewage water Plant was determined. Ascaris lumbricoides ova were treated with several gamma irradiation doses with (0.1, 0.2, 0.3, 0.4,...and 1.5 KGy). No morphological changes were observed on the eggs when directly examined microscopically after irradiation. However after two weeks of incubation at 37 degree centigrade the cell contents of the eggs which irradiated with 0.5 KGy and beyond were fragmented and scattered in the whole eggs and no larvae were observed after eight weeks of incubation. It is concluded that the dose 0.5 my be considered as the dose of choice if sewage water is to be treated by gamma rays.

Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

Science.gov (United States)

Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

2001-01-01

The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

Cytogenetic investigations of persons exposed to professional chronic low-dose irradiation

International Nuclear Information System (INIS)

Rangelov, V.; Mitev, L.; Petrunov, P.; Vesselinova, L.

2005-01-01

The problem of long term influence of low-doses occupational irradiation is connected with the real assessment of their consequences. The current cytogenetic investigations were done on persons working under occupational chronic external partial irradiation. Accumulated doses of external irradiation are surveyed. Data give ground for suggestion about the relationship between accumulated dose and chromosomal aberrations. The additional damage factors (diagnostic investigations, chemical substances, tobacco addict) have done the more significant influence upon aberrations appearance increasing

Assessment of population external irradiation doses with consideration of Rospotrebnadzor bodies equipment for monitoring of photon radiation dose

Directory of Open Access Journals (Sweden)

I. P. Stamat

2016-01-01

Full Text Available This paper provides review of equipment and methodology for measurement of photon radiation dose; analysis of possible reasons for considerable deviation between the Russian Federation population annual effective external irradiation doses and the relevant average global value. Data on Rospotrebnadzor bodies dosimetry equipment used for measurement of gamma radiation dose are collected and systematized. Over 60 kinds of dosimeters are used for monitoring of population external irradiation doses. Most of dosimeters used in the country have gas-discharge detectors (Geiger-Mueller counters, minor biochemical annunciators, etc. which have higher total values of own background level and of space radiation response than the modern dosimeters with scintillation detectors. This feature of dosimeters is apparently one of most plausible reasons of a bit overstating assessment of population external irradiation doses. The options for specification of population external irradiation doses assessment are: correction of gamma radiation dose measurement results with consideration of dosimeters own background level and space radiation response, introduction of more up-to-date dosimeters with scintillation detectors, etc. The most promising direction of research in verification of population external irradiation doses assessment is account of dosimetry equipment.

Effects of high dose gamma irradiation on ITO thin film properties

Energy Technology Data Exchange (ETDEWEB)

Alyamani, A. [National Nanotechnology Center, King Abdul-Aziz City for Science and Technology (KACST), Riyadh (Saudi Arabia); Mustapha, N., E-mail: nazirmustapha@hotmail.com [Dept. of Physics, College of Sciences, Al Imam Mohammad Ibn Saud Islamic University, P.O. Box 90950, Riyadh 11623 (Saudi Arabia)

2016-07-29

Transparent thin-film Indium Tin Oxides (ITO) were prepared on 0.7 mm thick glass substrates using a pulsed laser deposition (PLD) process with average thickness of 150 nm. The samples were then exposed to high gamma γ radiation doses by {sup 60}Co radioisotope. The films have been irradiated by performing exposure cycles up to 250 kGy total doses at room temperature. The surface structures before and after irradiation were analysed by x-ray diffraction. Atomic Force Microscopy (AFM) was performed on all samples before and after irradiation to investigate any change in the grain sizes, and also in the roughness of the ITO surface. We investigated the influence of γ irradiation on the spectra of transmittance T, in the ultraviolet-visible-near infrared spectrum using spectrophotometer measurements. Energy band gap E{sub g} was then calculated from the optical spectra for all ITO films. It was found that the optical band gap values decreased as the radiation dose was increased. To compare the effect of the irradiation on refractive index n and extinction coefficient k properties, additional measurements were done on the ITO samples before and after gamma irradiation using an ellipsometer. The optical constants n and k increased by increasing the irradiation doses. Electrical properties such as resistivity and sheet resistance were measured using the four-point probe method. The good optical, electrical and morphological properties maintained by the ITO films even after being exposed to high gamma irradiation doses, made them very favourable to be used as anodes for solar cells and as protective coatings in space windows. - Highlights: • Indium Tin Oxide (ITO) thin films were deposited by pulsed laser deposition. • Effects of Gamma irradiation were investigated. • Changes of optical transmission and electrical properties of ITO films were studied. • Intensity of the diffraction peaks and the film's structure changed with increasing irradiation doses. �

The application dose of irradiation for decontamination of dried marine fish

International Nuclear Information System (INIS)

Feng Min; Ji Ping; Li Lili; Zhu Jiating; Yang Ping; Lin Jiabing; Tang Yuxin; Wang Dening; Liu Chunquan

2009-01-01

The effects of irradiation decontamination on golden stripe fish, needle fish and blue whiting fish were studied based on analysis the contents of protein, fat, trace elements, heavy metals etc. before and after irradiation. The irradiation dose of 2.55 ∼ 13.65kGy was applied. The results show that 3kGy is enough to drop the number of total bacteria to less than 10 4 cfu/g; meanwhile, 5kGy is enough to drop the number of coliform bacteria to less than 30MPN/100g, which could meet the requirement of national hygiene standard of marine products of animal origin. Compared with the contents of protein, fat, trace elements, heavy metals, moisture and ash in control, all the contents of these indexes in irradiated samples are not changed significantly, though the content of protein is increased with irradiation dose and the content of moisture is decreased a little, while some trace elements contents are increased if irradiation dose is more than 10.4kGy. It is concluded that, the appropriate irradiation dose range for decontamination application of dried marine fishes is 5 ∼ 10kGy. (authors)

Inhibition of alloxan diabetes by low dose {gamma}-irradiation before alloxan administration

Energy Technology Data Exchange (ETDEWEB)

Yamaoka, Kiyonori [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.; Takehara, Yoshiki; Yoshioka, Tamotsu; Utsumi, Kozo

1994-10-01

We evaluated the inhibitory effects of whole body {sup 60}Co-{gamma} irradiation at a single low dose on alloxan-induced hyperglycemia in rats. (1) In rats that received alloxan, SOD activity in pancreas significantly decreased, but the decrease was inhibited by irradiation at a dose of 0.5 Gy. (2) Similarly, plasma peroxide, pancreatic peroxide, and blood glucose increased. However, the increase in pancreatic peroxide was inhibited by irradiation at a dose of 0.5 or 1.0 Gy and the increase in blood glucose by irradiation at 0.5 Gy. (3) After alloxan administration, degranulation was observed in cells, but this was inhibited by irradiation at 0.5 Gy. These results suggest that alloxan diabetes was inhibited by the increase of SOD activity in pancreas after low dose irradiation at 0.5 Gy. (author).

Dose dependent oxidation kinetics of lipids in fish during irradiation processing

International Nuclear Information System (INIS)

Tukenmez, I.; Ersen, M.S.; Bakioglu, A.T.; Bicer, A.; Pamuk, V.

1997-01-01

Kinetic aspects of the development of lipid oxidation in complex foods as fish in the course of irradiation were analyzed with respect to the associated formation of malonaldehyde (MA) through the reactions modified so as to be consistent with those in complex foods as fish. Air-packed anchovy (Engraulis encrasicholus) samples in polyethylene pouches were irradiated at the doses of 1, 2, 5, 10, 15,20 and 25 kGy at 20 o C in a Cs-137 gamma irradiator of 1.806 kGy/h dose rate. Immediately after each irradiation, MA contents of irradiated and unirradiated samples were determined by thiobarbituric acid test. Based on the MA formation, a kinetic model to simulate the apparent oxidation of lipid in fish as a function of irradiation dose was derived from the rate equations consistent with modified reactions. Kinetic parameters and simulation were related to conditions of lipid oxidation, and associated rancidity state of fish with respect to the doses applied in different irradiation-preservation processes. Numerical values of kinetic parameters based on the MA formation were found as a threshold dose of 0.375 kGy, an apparent yield of 1.871 μmol/kg kGy, and a maximum attainable concentration of 15.853 μmol/kg which may be used for process control and dosimetry. (author)

Reparative processes in spleen of rats irradiated with higher daily dose rates of continuous irradiation

Energy Technology Data Exchange (ETDEWEB)

Mackova, N; Praslicka, M; Misurova, E [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Prirodovedecka Fakulta

1975-01-01

Histological and DNA content values were used in evaluating repair processes in the spleen of rats at various intervals following continuous irradiation with daily doses of 50 R, 100 R, 200 R and 500 R (a total dose of 1000 R), and following a single exposure to 1000 R. Histological changes found immediately after irradiation indicated the induction of significant injuries, this mainly as a result of daily doses of 200 R and 500 R. The complete repair of the DNA content and of a number of erythroid elements and also a 70 to 80% regeneration of the white pulp took place within 25 days. The same period was found to be insufficient for the complete repair of megakaryocytes. No signs of repair were observed in spleen in the histological picture or DNA content after a single irradiation with a dose of 1000 R.

Reparative processes in spleen of rats irradiated with higher daily dose rates of continuous irradiation

International Nuclear Information System (INIS)

Mackova, N.; Praslicka, M.; Misurova, E.

1975-01-01

Histological and DNA content values were used in evaluating repair processes in the spleen of rats at various intervals following continuous irradiation with daily doses of 50 R, 100 R, 200 R and 500 R (a total dose of 1000 R), and following a single exposure to 1000 R. Histological changes found immediately after irradiation indicated the induction of significant injuries, this mainly as a result of daily doses of 200 R and 500 R. The complete repair of the DNA content and of a number of erythroid elements and also a 70 to 80% regeneration of the white pulp took place within 25 days. The same period was found to be insufficient for the complete repair of megakaryocytes. No signs of repair were observed in spleen in the histological picture or DNA content after a single irradiation with a dose of 1000 R. (author)

Preliminary report of a new treatment strategy for advanced pelvic malignancy: surgical resection and radiation therapy using afterloading catheters plus an inflatable displacement prosthesis in the treatment of advanced primary and recurrent rectal cancer

International Nuclear Information System (INIS)

Edington, H.D.; Hancock, S.; Coe, F.L.; Sugarbaker, P.H.

1986-01-01

An unsolved problem in colon and rectal surgery involves the treatment of locally invasive primary and recurrent rectal cancer. An approach is described that uses intracavitary iridium-192 sources in combination with a pelvic displacement prosthesis to augment external beam radiation doses to sites of residual disease identified at surgery. This approach should permit administration of tumoricidal doses of radiation to positive surgical margins minimizing radiation toxicity to the small bowel. The radiation source and all prosthetic materials are removed at the bedside within 2 weeks of surgery, ensuring accurate radiation dosimetry, minimizing infectious complications, and sparing the patient the need for full high-dose pelvic irradiation

Measures to minimize small intestine injury in the irradiated pelvis

International Nuclear Information System (INIS)

Green, N.; Iba, G.; Smith, W.R.

1975-01-01

Small intestine injury causes long-term suffering and high mortality. Five of 187 of our patients had developed serious small intestine injury. Four patients had corrective surgery. Three patients died. All were women. Subsequently, all patients who received definitive pelvic irradiation had small intestine roentgenograms to determine its location and mobility. Female patients, thin patients, and elderly patients had larger amounts of small intestine in the whole pelvis, a deeper cul de sac, and a greater incidence of relatively immobile small intestine. Patients with relatively immobile small intestine in the treatment field may be predisposed to injury. There was no relationship of the incidence of relatively immobile small intestine to prior pelvic surgery. We used the findings from the small intestine roentgenograms to modify individually the radiotherapy regimen so as to minimize the risk for small intestine injury. Patients were placed in the prone position to displace the small intestine out of the treatment fields used for booster dose irradiation. The treatment field was modified to exclude the small intestine. The total tumor dose delivered was determined by expectations for cure vs complications. To date, none of the patients in this study group has developed small intestine injury. Cadaver studies showed the feasibility of elective shortening of the pelvic cul de sac. The small intestine can be displaced away from the bladder, prostate, or cervix. (U.S.)

Efficacy of modest dose irradiation in combination with long-term endocrinal treatment for high-risk prostate cancer. A preliminary report

International Nuclear Information System (INIS)

Sasaki, Tomonari; Nakamura, Katsumasa; Shioyama, Yoshiyuki

2004-01-01

Although radiotherapy in combination with endocrinal manipulation has been identified as an effective treatment for patients with high-risk prostate cancer, the optimal dose for locoregional control of prostate cancer in combination with hormonal therapy has not yet been determined. The efficacy of modest doses of irradiation (60-62 Gy) combined with long-term endocrinal treatment for patients with high-risk prostate cancer (defined as a pretreatment prostate-specific antigen (PSA) level greater than 20 ng/ml or a Gleason's score of 8-10 or T3-T4 disease) was analyzed in 60 Japanese patients. The patients included in this study had received radical radiotherapy with long-term endocrinal manipulation in the period between 1993 and 2000. The median age of the patients was 70 years (range, 56-83). Neoadjuvant hormonal therapy with a median duration of 3.9 months was performed prior to radiotherapy, and hormonal therapy was continued until recurrence. A median dose of 61.4 Gy (range, 44-71.4) was delivered to the prostate. Pelvic node irradiation was performed in 49 patients (81.6%). After a median follow-up period of 28.5 months, the overall survival, cause-specific survival and biochemical relapse-free survival at 3 years were 94.4%, 96% and 89.8%, respectively. Local failure was observed in one patient, distant metastases were observed in three patients and a late toxic effect greater than Grade 2 was not observed in any patients. This study, though preliminary due to a short-term follow-up period, reveals the possibility that modest doses of irradiation combined with long-term endocrinal treatment could be an effective means of achieving excellent local control of high-risk prostate cancer. (author)

Study on cellular survival adaptive response induced by low dose irradiation of 153Sm

International Nuclear Information System (INIS)

Zhu Shoupeng; Xiao Dong

1999-01-01

The present study engages in determining whether low dose irradiation of 153 Sm could cut down the responsiveness of cellular survival to subsequent high dose exposure of 153 Sm so as to make an inquiry into approach the protective action of adaptive response by second irradiation of 153 Sm. Experimental results indicate that for inductive low dose of radionuclide 153 Sm 3.7 kBq/ml irradiated beforehand to cells has obvious resistant effect in succession after high dose irradiation of 153 Sm 3.7 x 10 2 kBq/ml was observed. Cells exposed to low dose irradiation of 153 Sm become adapted and therefore the subsequent cellular survival rate induced by high dose of 153 Sm is sufficiently higher than high dose of 153 Sm merely. It is evident that cellular survival adaptive response could be induced by pure low dose irradiation of 153 Sm only

Biliary and pancreatic secretions in abdominal irradiation

International Nuclear Information System (INIS)

Becciolini, A.; Cionini, L.; Cappellini, M.; Atzeni, G.

1979-01-01

The biliary and pancreatic secretions have been determined in patients given pelvic or para-aortic irradiation, with a dose of 50 Gy in the former group and between 36 and 40 Gy in the latter. A test meal containing polyethylene glycol (PEG) as reference substance was used. Each sample of the duodenal content was assayed for volume, PEG content, amylase and trypsin activity, pH and biliary secretion. No significant modifications of biliary and pancreatic secretions were demonstrated after irradiation, suggesting that these functions are not involved in the pathogenesis of the malabsorption radiation syndrome. (Auth.)

Dose and dose rate effects of whole-body gamma-irradiation: II. Hematological variables and cytokines

Science.gov (United States)

Gridley, D. S.; Pecaut, M. J.; Miller, G. M.; Moyers, M. F.; Nelson, G. A.

2001-01-01

The goal of part II of this study was to evaluate the effects of gamma-radiation on circulating blood cells, functional characteristics of splenocytes, and cytokine expression after whole-body irradiation at varying total doses and at low- and high-dose-rates (LDR, HDR). Young adult C57BL/6 mice (n = 75) were irradiated with either 1 cGy/min or 80 cGy/min photons from a 60Co source to cumulative doses of 0.5, 1.5, and 3.0 Gy. The animals were euthanized at 4 days post-exposure for in vitro assays. Significant dose- (but not dose-rate-) dependent decreases were observed in erythrocyte and blood leukocyte counts, hemoglobin, hematocrit, lipopolysaccharide (LPS)-induced 3H-thymidine incorporation, and interleukin-2 (IL-2) secretion by activated spleen cells when compared to sham-irradiated controls (p < 0.05). Basal proliferation of leukocytes in the blood and spleen increased significantly with increasing dose (p < 0.05). Significant dose rate effects were observed only in thrombocyte counts. Plasma levels of transforming growth factor-beta 1 (TGF-beta 1) and splenocyte secretion of tumor necrosis factor-alpha (TNF-alpha) were not affected by either the dose or dose rate of radiation. The data demonstrate that the responses of blood and spleen were largely dependent upon the total dose of radiation employed and that an 80-fold difference in the dose rate was not a significant factor in the great majority of measurements.

Blood compounds irradiation process: assessment of absorbed dose using Fricke and Thermoluminescent dosimetric systems

Energy Technology Data Exchange (ETDEWEB)

Soares, Gabriela de Amorim; Squair, Peterson Lima; Pinto, Fausto Carvalho; Belo, Luiz Claudio Meira; Grossi, Pablo Andrade [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN/MG), Belo Horizonte, MG (Brazil)], e-mail: gas@cdtn.br, e-mail: pls@cdtn.br, e-mail: fcp@cdtn.br, e-mail: lcmb@cdtn.br, e-mail: pabloag@cdtn.br

2009-07-01

The assessment of gamma absorbed doses in irradiation facilities allows the quality assurance and control of the irradiation process. The liability of dose measurements is assign to the metrological procedures adopted including the uncertainty evaluation. Fricke and TLD 800 dosimetric systems were used to measure absorbed dose in the blood compounds using the methodology presented in this paper. The measured absorbed doses were used for evaluating the effectiveness of the irradiation procedure and the gamma dose absorption inside the irradiation room of a gamma irradiation facility. The radiation eliminates the functional and proliferative capacities of donor T-lymphocytes, preventing Transfusion associated graft-versus-host disease (TA-GVHD), a possible complication of blood transfusions. The results show the applicability of such dosimetric systems in quality assurance programs, assessment of absorbed doses in blood compounds and dose uniformity assign to the blood compounds irradiation process by dose measurements in a range between 25 Gy and 100 Gy. (author)

Blood compounds irradiation process: assessment of absorbed dose using Fricke and Thermoluminescent dosimetric systems

International Nuclear Information System (INIS)

Soares, Gabriela de Amorim; Squair, Peterson Lima; Pinto, Fausto Carvalho; Belo, Luiz Claudio Meira; Grossi, Pablo Andrade

2009-01-01

The assessment of gamma absorbed doses in irradiation facilities allows the quality assurance and control of the irradiation process. The liability of dose measurements is assign to the metrological procedures adopted including the uncertainty evaluation. Fricke and TLD 800 dosimetric systems were used to measure absorbed dose in the blood compounds using the methodology presented in this paper. The measured absorbed doses were used for evaluating the effectiveness of the irradiation procedure and the gamma dose absorption inside the irradiation room of a gamma irradiation facility. The radiation eliminates the functional and proliferative capacities of donor T-lymphocytes, preventing Transfusion associated graft-versus-host disease (TA-GVHD), a possible complication of blood transfusions. The results show the applicability of such dosimetric systems in quality assurance programs, assessment of absorbed doses in blood compounds and dose uniformity assign to the blood compounds irradiation process by dose measurements in a range between 25 Gy and 100 Gy. (author)

Effects of irradiation source and dose level on quality characteristics of processed meat products

Science.gov (United States)

Ham, Youn-Kyung; Kim, Hyun-Wook; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Yong-Jae; Choi, Yun-Sang; Song, Beom-Seok; Park, Jong-Heum; Kim, Cheon-Jei

2017-01-01

The effect of irradiation source (gamma-ray, electron-beam, and X-ray) and dose levels on the physicochemical, organoleptic and microbial properties of cooked beef patties and pork sausages was studied, during 10 days of storage at 30±1 °C. The processed meat products were irradiated at 0, 2.5, 5, 7.5, and 10 kGy by three different irradiation sources. The pH of cooked beef patties and pork sausages was unaffected by irradiation sources or their doses. The redness of beef patties linearly decreased with increasing dose level (Pchanges in overall acceptability were observed for pork sausages regardless of irradiation source (P>0.05), while gamma-ray irradiated beef patties showed significantly decreased overall acceptability in a dose-dependent manner (Poxidation of samples was accelerated by irradiation depending on irradiation sources and dose levels during storage at 30 °C. E-beam reduced total aerobic bacteria of beef patties more effectively, while gamma-ray considerably decreased microbes in pork sausages as irradiation dose increased. The results of this study indicate that quality attributes of meat products, in particular color, lipid oxidation, and microbial properties are significantly influenced by the irradiation sources.

The biochemical changes of bone collagen after high-dose irradiation

International Nuclear Information System (INIS)

Tajiri, Ken

1980-01-01

In our clinic, patients with malignant bone tumors have been treated by high-dose irradiation therapy, 10,000-20,000 rads, for primary lesions. In order to study the biochemical changes of normal bone around tumor tissue, especially bone collagen, after high-dose irradiation, the author performed the following experiments. The right knee joint of rabbits was irradiated with either 6,000, 10,000, or 15,000 rads by 60 Co-γ ray. The cortical bone of the right tibial metaphysis was used for analyses and compared with the left tibia of the same rabbit. These studies were followed for one year after the final irradiation. The calcium, phosphorous and collagen contents of irradiated bone were remarkably changed. These data indicate that collagen biosynthesis of irradiated bone was decreased and the calcification was disturbed. An increase in the amount of total soluble collagen and a decrease in the amount of hydroxylysine bound sugar were observed. The ratio of β to α chains of the collagen molecule was also changed by the irradiation. The amount of reducible cross-links per hydroxyproline residue was strikingly increased three months after the final irradiation. These changes were remarkable especially in the 10,000 and 15,000 rads irradiated group and found to be recovered approximately six months to one year after the final irradiation. These findings indicate that high-dose irradiation reduces the stability of bone collagen both with the destruction of sugar bonds of hydroxylysine residues and the replacement of matured collagen matrix to immatured one which contain mostly labile reducible cross-links. (author)

Time-dose relationship of erythema in high energy photon irradiation therapy

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Hidetoshi (Gifu Prefectural Tajimi Hospital (Japan)); Sakuma, Sadayuki

1992-01-01

Skin doses of 100 patients who were treated with high energy ionizing irradiation during conventional irradiation therapy were measured by thermoluminescence dosimeter (TLD). In 87 of the 100 patients, acute hyperemic change of the skin (erythema) of the irradiated region was observed. In the other 13 patients, alopetia of the scalp was observed. The following conclusions were reached. The time-dose relationship was linear when erythema tolerance was used as an index, but not when alopecia was used. The tolerance dose for erythema was lower than previously reported. The slope of the isoeffect curve on the log-log plot of total absorbed skin dose against total number of days after the first irradiation was 0.68 when erythema was used as an index. This number is larger than previously reported results. We considered that erythema is significantly influenced by fraction size and that hyperfractionation is a promising method of irradiation, especially in Japan. Combined use of chemotherapeutic agents, such as 5-FU, accelerated erythema. The slope of combined treatment was 0.86. Observing acute hyperemic change of skin is considered to be a useful method of investigating the combined effects of chemotherapeutic agents on irradiation. (author).

Studies on chronic effects of lower dose level irradiation

International Nuclear Information System (INIS)

Yun, T.G.; Yun, Y.S.; Yun, M.S.

1980-01-01

This experiment is being carried out to elucidate the chronic effects of Co 60 (γ-ray) - low doses irradiation on JCR mice at 3rd week, 6th week, and 5th month after their birth. Experimental mice at 3rd week of age have been irradiated with Co 60 - 60mR weekly, Co 60 - 500mR weekly and Co 60 - 61R biweekly at the dose rate of 60mR per second for 23 weeks until now. Co 60 - 61R irradiated mice were subdivided into Co 60 - alone group and Co 60 combined with red ginseng extracts group. In their survivor's rate and their body weight etc., no significant differences between control groups and test groups in these experimental mice. Experimented mice at 6 weeks and 5 months of age are also being irradiated with Co 60 in the same doses as the above for 14 weeks and 8 weeks until present. In these experimental groups, there are also no significant differences between control groups and experimental groups in their survivor's rate and their body weight

High-dose MeV electron irradiation of Si-SiO2 structures implanted with high doses Si+

Science.gov (United States)

Kaschieva, S.; Angelov, Ch; Dmitriev, S. N.

2018-03-01

The influence was studied of 22-MeV electron irradiation on Si-SiO2 structures implanted with high-fluence Si+ ions. Our earlier works demonstrated that Si redistribution is observed in Si+-ion-implanted Si-SiO2 structures (after MeV electron irradiation) only in the case when ion implantation is carried out with a higher fluence (1016 cm-2). We focused our attention on the interaction of high-dose MeV electron irradiation (6.0×1016 cm-2) with n-Si-SiO2 structures implanted with Si+ ions (fluence 5.4×1016 cm-2 of the same order magnitude). The redistribution of both oxygen and silicon atoms in the implanted Si-SiO2 samples after MeV electron irradiation was studied by Rutherford back-scattering (RBS) spectroscopy in combination with a channeling technique (RBS/C). Our results demonstrated that the redistribution of oxygen and silicon atoms in the implanted samples reaches saturation after these high doses of MeV electron irradiation. The transformation of amorphous SiO2 surface into crystalline Si nanostructures (after MeV electron irradiation) was evidenced by atomic force microscopy (AFM). Silicon nanocrystals are formed on the SiO2 surface after MeV electron irradiation. The shape and number of the Si nanocrystals on the SiO2 surface depend on the MeV electron irradiation, while their size increases with the dose. The mean Si nanocrystals height is 16-20 nm after irradiation with MeV electrons at the dose of 6.0×1016 cm-2.

The role and strategy of IMRT in radiotherapy of pelvic tumors: Dose escalation and critical organ sparing in prostate cancer

International Nuclear Information System (INIS)

Liu, Y.-M.; Shiau, C.-Y.; Lee, M.-L.; Huang, P.-I.; Hsieh, C.-M.; Chen, P.-H.; Lin, Y.-H.; Wang, L.-W.; Yen, S.-H.

2007-01-01

Purpose: To investigate the intensity-modulated radiotherapy (IMRT) strategy in dose escalation of prostate and pelvic lymph nodes. Methods and Materials: Plan dosimetric data of 10 prostate cancer patients were compared with two-dimensional (2D) or IMRT techniques for pelvis (two-dimensional whole pelvic radiation therapy [2D-WPRT] or IM-WPRT) to receive 50 Gy or 54 Gy and additional prostate boost by three-dimensional conformal radiation therapy or IMRT (3D-PBRT or IM-PBRT) techniques up to 72 Gy or 78 Gy. Dose-volume histograms (DVHs), normal tissue complication probabilities (NTCP) of critical organ, and conformity of target volume in various combinations were calculated. Results: In DVH analysis, the plans with IM-WPRT (54 Gy) and additional boost up to 78 Gy had lower rectal and bladder volume percentage at 50 Gy and 60 Gy, compared with those with 2D-WPRT (50 Gy) and additional boost up to 72 Gy or 78 Gy. Those with IM-WPRT (54 Gy) also had better small bowel sparing at 30 Gy and 50 Gy, compared with those with 2D-WPRT (50 Gy). In NTCP, those with IM-WPRT and total dose of 78 Gy achieved lower complication rates in rectum and small bowel, compared with those of 2D-WPRT with total dose of 72 Gy. In conformity, those with IM-WPRT had better conformity compared with those with 2D-WPRT with significance (p < 0.005). No significant difference in DVHs, NTCP, or conformity was found between IM-PBRT and 3D-PBRT after IM-WPRT. Conclusions: Initial pelvic IMRT is the most important strategy in dose escalation and critical organ sparing. IM-WPRT is recommended for patients requiring WPRT. There is not much benefit for critical organ sparing by IMRT after 2D-WPRT

Normal tissue tolerance to external beam radiation therapy: Ovaries; Tolerance a l'irradiation des tissus sains: les ovaires

Energy Technology Data Exchange (ETDEWEB)

Gross, E.; Champetier, C.; Zaccariotto, A.; Duberge, T.; Guerder, C. [Departement de radiotherapie, hopital de la Timone, 13 - Marseille (France); Pointreau, Y. [Service Corad, pole Henry-S.-Kaplan, CHU Bretonneau, 37 - Tours (France); Ortholan, C. [Service de radiotherapie, centre Antoine-Lacassagne, 06 - Nice (France); Chauvet, B. [Institut Sainte-Catherine, 84 - Avignon (France)

2010-07-15

Clinical situations requiring protections of ovaries are mainly paediatric irradiations and pre-menopausal pelvic irradiations. The main complication of ovarian irradiation is the induced castration. Ovaries are extremely radiosensitive organs with strong interpersonal variations. The castrative effect of irradiation depends mainly on two factors: patient's age and the dose delivered to ovaries. The surgical technique of ovarian transposition allows to minimize the dose received by ovaries by taking them away, out of irradiation fields; the aim is to exclude them from the volume receiving 5 Gy or more, and if possible from those receiving 2 Gy. This technique becomes integrated into a multidisciplinary approach of conservation of fertility for patients exposed to other cytotoxic treatments. (authors)

Dose mapping of the multi-purpose gamma irradiation facility

Energy Technology Data Exchange (ETDEWEB)

Cabalfin, E G; Lanuza, L G; Villamater, D T [Irradiation Services, Nuclear Services and Training Division, Philippine Nuclear Research Institute, Quezon City (Philippines)

1989-12-01

In radiation processing, reliable dosimetry constitutes a very important part of process control and quality assurance. Radiation dosimetry is the only acceptable method to guarantee that the irradiated product has undergone the correct radiation treatment. In preparation therefore, for the routine operation of the newly installed multi-purpose gamma irradiation facility at the Philippine Nuclear Research Institute (PNRI), dose mapping distribution studies were undertaken. Results of dose distribution in air as well as in dummy product are presented. The effects of product bulk density, product geometry and product to source distance on minimum absorbed dose and uniformity ratio have been determined. (Author).

Dose mapping of the multi-purpose gamma irradiation facility

International Nuclear Information System (INIS)

Cabalfin, E.G.; Lanuza, L.G.; Villamater, D.T.

1989-01-01

In radiation processing, reliable dosimetry constitutes a very important part of process control and quality assurance. Radiation dosimetry is the only acceptable method to guarantee that the irradiated product has undergone the correct radiation treatment. In preparation therefore, for the routine operation of the newly installed multi-purpose gamma irradiation facility at the Philippine Nuclear Research Institute (PNRI), dose mapping distribution studies were undertaken. Results of dose distribution in air as well as in dummy product are presented. The effects of product bulk density, product geometry and product to source distance on minimum absorbed dose and uniformity ratio have been determined. (Author)

Decreasing Irradiated Rat Lung Volume Changes Dose-Limiting Toxicity From Early to Late Effects

Energy Technology Data Exchange (ETDEWEB)

Veen, Sonja J. van der; Faber, Hette; Ghobadi, Ghazaleh [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Brandenburg, Sytze [KVI Center for Advanced Radiation Research, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Coppes, Robert P. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Luijk, Peter van, E-mail: p.van.luijk@umcg.nl [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

2016-01-01

Purpose: Technological developments in radiation therapy result in smaller irradiated volumes of normal tissue. Because the risk of radiation therapy-induced toxicity generally depends on irradiated volume, changing volume could change the dose-limiting toxicity of a treatment. Recently, in our rat model, we found that early radiation-induced lung dysfunction (RILD) was closely related to irradiated volume dependent vascular remodeling besides inflammation. The exact relationship between early and late RILD is still unknown. Therefore, in this preclinical study we investigated the dose-volume relationship of late RILD, assessed its dependence on early and late pathologies and studied if decreasing irradiated volume changed the dose-limiting toxicity. Methods and Materials: A volume of 25%, 32%, 50%, 63%, 88%, or 100% of the rat lung was irradiated using protons. Until 26 weeks after irradiation, respiratory rates were measured. Macrovascular remodeling, pulmonary inflammation, and fibrosis were assessed at 26 weeks after irradiation. For all endpoints dose-volume response curves were made. These results were compared to our previously published early lung effects. Results: Early vascular remodeling and inflammation correlated significantly with early RILD. Late RILD correlated with inflammation and fibrosis, but not with vascular remodeling. In contrast to the early effects, late vascular remodeling, inflammation and fibrosis showed a primarily dose but not volume dependence. Comparison of respiratory rate increases early and late after irradiation for the different dose-distributions indicated that with decreasing irradiated volumes, the dose-limiting toxicity changed from early to late RILD. Conclusions: In our rat model, different pathologies underlie early and late RILD with different dose-volume dependencies. Consequently, the dose-limiting toxicity changed from early to late dysfunction when the irradiated volume was reduced. In patients, early and late

Effect of Low-Dose Irradiation on Biochemical and Immunological Responses

International Nuclear Information System (INIS)

Shabon, M.H.; Sayed, Z.S.; El-Gawish, M.A.; Mahdy, E.M.E.; Shosha, W.Gh.

2008-01-01

Lipid peroxidation (Malondialdehyde), Lactate dehydrogenase, Iron Concentration, IL-6 and IL-1β concentration were determined in Seventy-two male albino rats divided in two main groups. The first one was subdivided into 7 subgroups; control and 6 irradiated subgroups with 0.1, 0.2, 0.3, 0.5, 0.7, and 1 Gy single dose of gamma radiation. The other was subdivided into 4 irradiated subgroups with fractionated dose .-radiation of 0.3, 0.7 and 1 Gy with 0.1 Gy per day and the last subgroup 1 Gy with 0.2 Gy daily. All animals were sacrificed after three days of the last irradiation dose. The results revealed that all biochemical parameters were increased in rats exposed to fractionated more than single doses. In conclusion, the data of this study highlight on the beneficial and stimulatory effect of low ionizing radiation doses (≥ 1Gy) whether single or fractionated on some biochemical and immunological parameters. These findings may be fruitful for those who undergo radiotherapy as well as the dose-effect relationship

Radioprotective effect of RSP-CM on mice irradiated with different doses

International Nuclear Information System (INIS)

Zhang Xia; Yang Rujun; Zhang Xin; Yang Yunfang; Jin Zhijun; Xiang Yingsong

2000-01-01

Objective: To investigate the radioprotective effects of cytokines on hematopoietic impairment of irradiated mice. Methods: Using RSP-CM and LP3-CM respectively originated GM-CSF and G-CSF to treat ICR mice irradiated with different doses of 60 Co γ-rays. The 30-day survival rate of mice, the mean survival days of dead mice were determined and the numbers of peripheral white blood cells and BMC of part of the mice were counted. At the same time, GM clonogenic activity of BM was assayed. Results:RSP-CM could effectively raise 30-day survival rate of mice irradiated with 7.5 Gy. However, LP3-CM had no obvious effect. Judging from the comparative survival ratio, only the RSP-CM treated group showed protective effect on the 8.0 Gy -irradiated mice. The 8.5 Gy-irradiated mice all died within 30 days, indicating that GM-CSF had weak effect on higher dose-irradiated mice. Conclusion: GM-CSF can stimulate the hematopoietic system of irradiated mice, and has dose-effect and time-effect relations. M-CSF used singly has no obvious effect

The dose effect of irradiated rice pollen on double fertilization

International Nuclear Information System (INIS)

Wang Houcong; Chen Zhengming; Chen Ruming; Qiu Simi; Yang Juemin; Yang Huijie

1995-01-01

The mature panicles of rice were treated with 60 Co γ-rays in the range of 0∼0.372 kGy. The male sterile line used as the female plants were fertilized with γ-irradiated pollen manually. The dose effect of the irradiated pollen on double fertilization was investigated. It was found that double fertilization of the irradiated pollen was suppressed to different degrees as compared with the control. The effect was noticeable as that the fusion time of the male nucleolus with the female one was delayed with the increasing of γ-radiation dose. The delayed time was less than 13 hours when the dose was below 0.186 kGy and it was more than 15 hours when the dose was above 0.279 kGy. Furthermore, several types of deformed embryonic cells and endosperm nuclei were observed

Analysis of Low Dose Irradiation Damages in Structural Ferritic/Martensitic Steels by Proton Irradiation and Nanoindentation

International Nuclear Information System (INIS)

Waseem, Owais A.; Ryu, Ho Jin; Park, Byong Guk; Jeong, Jong Ryul; Maeng, Cheol Soo; Lee, Myoung Goo

2016-01-01

As a result, ferritic-martensitic steels find applications in the in-core and out-of-core components which include ducts, piping, pressure vessel and cladding, etc. Due to ferromagnetism of F/M steel, it has been successfully employed in solenoid type fuel injector. Although the irradiation induced degradation in ferritic martensitic steels is lower as compare to (i) reduced activation steels, (ii) austenitic steels and (iii) martensitic steels, F/M steels are still prone to irradiation induced hardening and void swelling. The irradiation behavior may become more sophisticated due to transmutation and production of helium and hydrogen. The ductile to brittle transition temperature of F/M steels is also expected to increase due to irradiation. These irradiation induced degradations may deteriorate the integrity of F/M components. As a result of these investigations, it has found that the F/M steels experience no irradiation hardening above 400 .deg. C, but below this temperature, up to 350 .deg. C, weak hardening is observed. The irradiation hardening becomes more pronounced below 300 .deg. C. Moreover, the irradiation hardening has also found dependent upon radiation damage. The hardening was found increasing with increasing dose. Due to pronounced irradiation hardening below 300 .deg. C and increasing radiation damage with increasing dose (even at low dpa), it is required to investigate the post irradiation mechanical properties of F/M steel, in order to confirm its usefulness in structural and magnetic components which experience lifetime doses as low as 1x10"-"5 dpa.

Analysis of Low Dose Irradiation Damages in Structural Ferritic/Martensitic Steels by Proton Irradiation and Nanoindentation

Energy Technology Data Exchange (ETDEWEB)

Waseem, Owais A.; Ryu, Ho Jin; Park, Byong Guk [KAIST, Daejeon (Korea, Republic of); Jeong, Jong Ryul [Chungnam University, Daejeon (Korea, Republic of); Maeng, Cheol Soo; Lee, Myoung Goo [KEPCO, Daejeon (Korea, Republic of)

2016-05-15

As a result, ferritic-martensitic steels find applications in the in-core and out-of-core components which include ducts, piping, pressure vessel and cladding, etc. Due to ferromagnetism of F/M steel, it has been successfully employed in solenoid type fuel injector. Although the irradiation induced degradation in ferritic martensitic steels is lower as compare to (i) reduced activation steels, (ii) austenitic steels and (iii) martensitic steels, F/M steels are still prone to irradiation induced hardening and void swelling. The irradiation behavior may become more sophisticated due to transmutation and production of helium and hydrogen. The ductile to brittle transition temperature of F/M steels is also expected to increase due to irradiation. These irradiation induced degradations may deteriorate the integrity of F/M components. As a result of these investigations, it has found that the F/M steels experience no irradiation hardening above 400 .deg. C, but below this temperature, up to 350 .deg. C, weak hardening is observed. The irradiation hardening becomes more pronounced below 300 .deg. C. Moreover, the irradiation hardening has also found dependent upon radiation damage. The hardening was found increasing with increasing dose. Due to pronounced irradiation hardening below 300 .deg. C and increasing radiation damage with increasing dose (even at low dpa), it is required to investigate the post irradiation mechanical properties of F/M steel, in order to confirm its usefulness in structural and magnetic components which experience lifetime doses as low as 1x10{sup -5} dpa.

Does prophylactic treatment with proteolytic enzymes reduce acute toxicity of adjuvant pelvic irradiation? Results of a double-blind randomized trial

International Nuclear Information System (INIS)

Martin, Thomas; Uhder, Kerstin; Kurek, Ralf; Roeddiger, Sandra; Schneider, Lida; Vogt, Hans-Georg; Heyd, Reinhard; Zamboglou, Nikolaos

2002-01-01

Purpose: Does prophylactic treatment with proteolytic enzymes reduce acute toxicity of adjuvant pelvic radiotherapy? Material and methods: Fifty-six patients with an indication for adjuvant pelvic irradiation after curative surgery were double-blind randomized. All patients took 3x4 capsules study medication daily during radiotherapy. Twenty-eight patients in the enzyme group (EG) received capsules containing papain, trypsin and chymotrypsin, 28 in the placebo group (PG) received placebo capsules. All patients were irradiated with 5x1.8 Gy weekly to 50.4 Gy using four-field-box technique after CT-based planning. Primary objective was the grade of diarrhea, nausea, vomiting, fatigue and epitheliolysis during radiotherapy. Secondary objectives were the number of supportive medications and treatment interruptions due to acute toxicity. Results: None/mild diarrhea: 43% EG, 64% PG. Moderate/severe diarrhea: 57% EG, 36% PG (P=0.11). Mean duration: 11 days in EG, 10 days in PG. None/mild nausea: 93% EG, 93% PG. Moderate/severe nausea: 7% EG, 7% PG. None/mild vomiting: 100% EG, 97% PG. None/mild fatigue: 82% EG, 93% PG. Moderate/severe fatigue: 18% EG, 7% PG (P=0.23). None/mild epitheliolysis: 75% EG, 93% PG. Moderate/severe epitheliolysis: 25% EG, 7% PG (P=0.16). Treatment interruption (mean days): 2.44 in EG, 1.46 in PG. Number of supportive medication: 29 in EG, 19 in PG. Conclusions: The prophylactic use of proteolytic enzymes does not reduce acute toxicities, treatment interruptions and number of supportive medication and therefore does not improve tolerance of adjuvant pelvic radiotherapy

Analytical dose modeling for preclinical proton irradiation of millimetric targets.

Science.gov (United States)

Vanstalle, Marie; Constanzo, Julie; Karakaya, Yusuf; Finck, Christian; Rousseau, Marc; Brasse, David

2018-01-01

Due to the considerable development of proton radiotherapy, several proton platforms have emerged to irradiate small animals in order to study the biological effectiveness of proton radiation. A dedicated analytical treatment planning tool was developed in this study to accurately calculate the delivered dose given the specific constraints imposed by the small dimensions of the irradiated areas. The treatment planning system (TPS) developed in this study is based on an analytical formulation of the Bragg peak and uses experimental range values of protons. The method was validated after comparison with experimental data from the literature and then compared to Monte Carlo simulations conducted using Geant4. Three examples of treatment planning, performed with phantoms made of water targets and bone-slab insert, were generated with the analytical formulation and Geant4. Each treatment planning was evaluated using dose-volume histograms and gamma index maps. We demonstrate the value of the analytical function for mouse irradiation, which requires a targeting accuracy of 0.1 mm. Using the appropriate database, the analytical modeling limits the errors caused by misestimating the stopping power. For example, 99% of a 1-mm tumor irradiated with a 24-MeV beam receives the prescribed dose. The analytical dose deviations from the prescribed dose remain within the dose tolerances stated by report 62 of the International Commission on Radiation Units and Measurements for all tested configurations. In addition, the gamma index maps show that the highly constrained targeting accuracy of 0.1 mm for mouse irradiation leads to a significant disagreement between Geant4 and the reference. This simulated treatment planning is nevertheless compatible with a targeting accuracy exceeding 0.2 mm, corresponding to rat and rabbit irradiations. Good dose accuracy for millimetric tumors is achieved with the analytical calculation used in this work. These volume sizes are typical in mouse

Identification and dose evaluation of irradiated beef containing bones

International Nuclear Information System (INIS)

Mangiacotti, M.; Alberti, A.; Fuochi, P.G.; Chiesa, L.M.

2011-01-01

Complete text of publication follows. Food irradiation is a well-established technique to extend the food shelf life and to reduce the food-related health hazards caused by pathogenic micro-organisms. At present, radiation treatment is permitted for various categories of food and food ingredients in many countries. At the European level, irradiation of food is regulated by the European Directives 1999/2/EC and 1999/3/EC. Community legislation states that any food or food ingredients, authorised in the European Union, must be labelled with the word 'irradiated' and that every year each Member State has to carry out checks at the product marketing stage to enforce correct labelling. The present work aimed at identifying irradiated beef meat by using a reliable and sensitive detection of DNA comets as screening biological method and performing an Electron Spin Resonance (ESR) spectrometry as confirmatory qualitative standard. The influence of storage conditions and time after irradiation on DNA degradation was also investigated. Furthermore the application of ESR technique as a quantitative method was successfully applied to beef bones, using the approach of calibration curve. Results, although the limited statistics, proved for reliability of the dose reconstruction method and blind tests were carried out resulting in very satisfactory difference between actual treatment dose and reconstructed dose.

Effect of low doses gamma irradiation of cotton seeds

International Nuclear Information System (INIS)

Al-Oudat, M.; Khalifa, Kh.

1996-01-01

Field experiments and then large scale application of irradiated cotton seeds (C.V. Aleppo-40) were carried out during three seasons (1986, 1987 and 1988) for field experiment at ACSAD Station in Dier-Ezzor and 1988, 1989 and 1990 for large scale application at Euphrate's Basin, Al-Ghab and Salamia, farmers farms. The above areas were selected as they represent major cotton production areas in Syria. The aims of the experiments were to study the effect of low doses of gamma irradiation 0, 5, 10, 20, 30, 40 and 50 Gy on cotton yield and to look for the optimum dose of gamma irradiation to obtain best results. The results show that, there were positive effect (P<0.95) for doses 5-30 Gy in increasing cotton yield. The highest increase was at dose of 10 Gy. which as 19.5% higher than control. For the large scale application using 10 Gy the increase in cotton yield varied from 10-39% compared to control. (author). 11 refs., 6 figs

Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation

International Nuclear Information System (INIS)

Lee, Eun-Jung; Kim, Jun Won; Yoo, Hyun; Kwak, Woori; Choi, Won Hoon; Cho, Seoae; Choi, Yu Jeong; Lee, Yoon-Jin; Cho, Jaeho

2015-01-01

We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm 2 fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C–C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in a co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin. - Highlights: • Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33. • Vascular endothelial cells damaged by high-dose radiation secrete IL-33. • Blocking IL-33 suppressed migration of inflammatory cells and cytokine secretion. • IL-33

Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun-Jung, E-mail: forejs2@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Jun Won, E-mail: JUNWON@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Yoo, Hyun, E-mail: gochunghee@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kwak, Woori, E-mail: asleo02@snu.ac.kr [Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-747 (Korea, Republic of); Choi, Won Hoon, E-mail: wonhoon@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Cho, Seoae, E-mail: seoae@cnkgenomics.com [C& K Genomics, Seoul National University Mt.4-2, Main Bldg. #514, SNU Research Park, NakSeoungDae, Gwanakgu, Seoul 151-919 (Korea, Republic of); Choi, Yu Jeong, E-mail: yunk9275@daum.net [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Lee, Yoon-Jin, E-mail: yjlee8@kirams.re.kr [Division of Radiation Effects, Research Center for Radiotherapy, Korea Institute of Radiological & Medical Sciences, Seoul 139-760 (Korea, Republic of); Cho, Jaeho, E-mail: jjhmd@yuhs.ac [Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of)

2015-08-14

We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm{sup 2} fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C–C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in a co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin. - Highlights: • Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33. • Vascular endothelial cells damaged by high-dose radiation secrete IL-33. • Blocking IL-33 suppressed migration of inflammatory cells and cytokine secretion. • IL

Modifying effect of low dose irradiation

International Nuclear Information System (INIS)

Kalendo, G.S.

1989-01-01

It is shown that irradiation of Hela cells with stimulating doses of 0,1 Gy changes the cells' response to the subsequent radiation effect of greater value: instead of DNA synthesis inhibition stimulation takes place. Modifying effect of preliminary irradiation with 0,1 Gy manifests it self only in case if there is a certain time interval not less than 3 minutes and not more than 10 minutes (3-5 minutes is optimal interval). Data on modifying effect with 0,1 Gy at subcellular and cellular-population levels are presented. 21 refs.; 6 figs

Low dose irradiation and biological defense mechanisms

International Nuclear Information System (INIS)

Sugahara, Tsutomu; Sagan, L.A.; Aoyama, Takashi

1992-01-01

It has been generally accepted in the context of radiation protection that ionizing radiation has some adverse effect even at low doses. However, epidemiological studies of human populations cannot definitively show its existence or absence. Furthermore, recent studies of populations living in areas of different background radiation levels reported some decrease in adverse health effects at high background levels. Genetic studies of atomic bomb survivors failed to produce statistically significant findings on the mutagenic effects of ionizing radiation. A British study however, suggests that a father's exposure to low dose radiation on the job may increase his children's risk of leukemia. On the other hand, many experimental studies have raised the possibility that low doses of ionizing radiation may not be harmful or may even produce stimulating or adaptive responses. The term 'hormesis' has come to be used to describe these phenomena produced by low doses of ionizing radiation when they were beneficial for the organisms studied. At the end of the International Conference on Low Dose Irradiation one conclusion appeared to be justified: radiation produces an adaptive response, though it is not universally detected yet. The conference failed to obtain any consensus on risk assessment at low doses, but raised many problems to be dealt with by future studies. The editors therefore believe that the Proceedings will be useful for all scientists and people concerned with radiation protection and the biological effects of low-dose irradiation

Patient-related factors determining geometry of intracavitary applicators and pelvic dose distribution during cervical cancer brachytherapy

International Nuclear Information System (INIS)

Senkus-Konefka, Elzbieta; Kobierska, Anna; Jassem, Jacek; Badzio, Andrezej

1997-01-01

Purpose: The aim of this study was to assess retrospectively the influence of the size of cervical cancer brachytherapy applicators (ovoids and uterine tandems) on pelvic dose distribution and to analyze the impact of various patient-and disease-related factors on applicators' geometry and on dose distribution in particular applications. Methods and Materials: The subject of this study were 356 cervical cancer patients treated with Selectron LDR as a part of their radical radiotherapy. Analyzed factors included patient age, weight, number of vaginal deliveries, and disease stage. Results: The use of larger vaginal applicators resulted in lower bladder and rectum doses and in higher point B doses (all p < 0.0001); longer uterine tandems produced lower rectum doses and higher point B doses (both p < 0.0001). Increasing patient age and disease stage resulted in a decreased frequency of use of large ovoids (both p < 0.0001) and of long tandems (age: p = 0.0069, stage: p = 0.004). As a result, higher doses to bladder (age: p < 0.0001, stage: p = 0.017) and rectum (age: p = 0.037, stage: p = 0.011) were observed. Increasing age also resulted in lower point B doses (p < 0.0001). Increasing patient weight correlated with less frequent use of long tandems (p = 0.0015) and with higher bladder doses (p = 0.04). Higher number of vaginal deliveries was related to the increase in the use of long tandems (p = 0.002); in patients who had had at least one vaginal delivery, point B doses were significantly higher (p = 0.0059). In multivariate analysis ovoid size and uterine tandem length were dependent on patient age (respectively: p < 0.001 and p = 0.001), disease stage (respectively: p = 0.003 and p = 0.008) and on the number of vaginal deliveries (respectively: p = 0.07 and p 0.008). Doses to critical organs and to points B were dependent on patient age (respectively: p < 0.001, p = 0.011, and p < 0.001) and on disease stage (respectively: p < 0.001, p = 0.004, and p = 0

Pre-1989 epidemiological surveys of low-level dose pre-conception irradiation

International Nuclear Information System (INIS)

Rose, K.S.B.

1990-01-01

Information from 59 pre-1989 epidemiological surveys concerning pre-conception irradiation at doses less than 0.1 Gy has been collated to determine whether any consistent patterns of health effects emerge. The surveys are considered in three groups: childhood malignancies, Down's syndrome and indicators of reproductive damage. Although a pattern is observed for Down's syndrome, no reliable associations are apparent for childhood malignancies (where all surveys pre-date the Gardner survey at Sellafield) or indications of reproductive damage. The twelve surveys of Down's syndrome in relation to maternal pre-conception irradiation received for medical reasons show a pattern consistent with a doubling dose of about 20 mGy. This doubling dose value is, however, not based on individual measurements of ovarian dose and is inconsistent with results from high-level dose surveys. There is no association between paternal irradiation and Down's syndrome. (author)

Relaxation behavior and dose dependence of radiation induced radicals in irradiated mango

International Nuclear Information System (INIS)

Kameya, Hiromi; Kakita, Daisuke; Kaimori, Yoshihiko; Ukai, Mitsuko; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Shimoyama, Yuhei

2010-01-01

Mangoes are imported to Japan after treated with hot water. Recently, irradiated mangoes imported to U. S. are widely used. This paper reports on the ESR method for analyzing the radiation induced radicals of irradiated mangoes. Upon the γ ray irradiation, a strong single peak in the flesh and skin of mangoes was observed at g=2.004. This singlet peak may be attributed to organic free radicals. The ESR spectra of the flesh and skin of mangoes showed the radiation induced radicals due to cellulose by irradiation over 12 kGy. The relaxation times (T 1 and T 2 ) of the singlet signal were calculated. T 2 showed dose response according to increasing the irradiation dose levels, while T 1 was almost constant. The value of (T 1 T 2 ) 1/2 showed the dependence of irradiation dose level. (author)

Accelerated Irradiations for High Dose Microstructures in Fast Reactor Alloys

Energy Technology Data Exchange (ETDEWEB)

Jiao, Zhijie [Univ. of Michigan, Ann Arbor, MI (United States)

2017-03-31

The objective of this project is to determine the extent to which high dose rate, self-ion irradiation can be used as an accelerated irradiation tool to understand microstructure evolution at high doses and temperatures relevant to advanced fast reactors. We will accomplish the goal by evaluating phase stability and swelling of F-M alloys relevant to SFR systems at very high dose by combining experiment and modeling in an effort to obtain a quantitative description of the processes at high and low damage rates.

Wholesomeness of food irradiated with doses above 10 kGy

Energy Technology Data Exchange (ETDEWEB)

Kaferstein, F [Director, Programme of Food Safety and Food Aid, WHO, CH-1211, Geneva 27, (Switzerland)

1998-12-31

Strictly from the scientific point of view, no ceiling should be set for food irradiated with doses greater than the currently recommended upper level of 10 kGy by the Codex Alimentarius Commission. The food irradiation technology itself is safe to such a degree that as long as sensory qualities of food are retained and harmful microorganisms are destroyed, the actual amount of ionizing radiation applied is of secondary consideration. That was the main conclusion of a week-long meeting on high dose irradiation organized jointly by the World Health Organization (WHO), the United Nations Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA). The knowledge of what can and does occur chemically in high dose irradiated foods which derives from over 50 years of research tells us that one can go as high as 75 kGy, as has already been done in some countries, and the result is the same food is safe and wholesome and nutritionally adequate. (Author)

Wholesomeness of food irradiated with doses above 10 kGy

International Nuclear Information System (INIS)

Kaferstein, F.

1997-01-01

Strictly from the scientific point of view, no ceiling should be set for food irradiated with doses greater than the currently recommended upper level of 10 kGy by the Codex Alimentarius Commission. The food irradiation technology itself is safe to such a degree that as long as sensory qualities of food are retained and harmful microorganisms are destroyed, the actual amount of ionizing radiation applied is of secondary consideration. That was the main conclusion of a week-long meeting on high dose irradiation organized jointly by the World Health Organization (WHO), the United Nations Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA). The knowledge of what can and does occur chemically in high dose irradiated foods which derives from over 50 years of research tells us that one can go as high as 75 kGy, as has already been done in some countries, and the result is the same food is safe and wholesome and nutritionally adequate. (Author)

Wholesomeness of food irradiated with doses above 10 kGy

Energy Technology Data Exchange (ETDEWEB)

Kaferstein, F. [Director, Programme of Food Safety and Food Aid, WHO, CH-1211, Geneva 27, (Switzerland)

1997-12-31

Strictly from the scientific point of view, no ceiling should be set for food irradiated with doses greater than the currently recommended upper level of 10 kGy by the Codex Alimentarius Commission. The food irradiation technology itself is safe to such a degree that as long as sensory qualities of food are retained and harmful microorganisms are destroyed, the actual amount of ionizing radiation applied is of secondary consideration. That was the main conclusion of a week-long meeting on high dose irradiation organized jointly by the World Health Organization (WHO), the United Nations Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA). The knowledge of what can and does occur chemically in high dose irradiated foods which derives from over 50 years of research tells us that one can go as high as 75 kGy, as has already been done in some countries, and the result is the same food is safe and wholesome and nutritionally adequate. (Author)

Suppression of carcinogenesis in mice by adaptive responses to low dose rate irradiation

Energy Technology Data Exchange (ETDEWEB)

Sakai, Kazuo; Iwasaki, Toshiyasu; Hoshi, Yuko; Nomura, Takaharu; Ina, Yasuhiro; Tanooka, Hiroshi [Central Research Institute of Electric Power Industry, Low Dose Radiation Research Center, Komae, Tokyo (Japan)

2003-07-01

Effects of prolonged low-dose-rate irradiation on the process of carcinogenesis were examined in mice treated with chemical carcinogen or irradiated with high doses of X-rays. Female ICR mice, 5 week-old, 35 in each group, were exposed to gamma-rays from a {sup 137}Cs source in the long-term low dose rate irradiation facility at CRIEPI. The dose rate was 2.6 mGy/hr (A), 0.96 mGy/hr (B), or 0.30 mGy/hr (C). Thirty-five days later, the mice were injected into the groin with 0.5 mg of methylcholanthrene (MC) dissolved in olive oil and irradiation was continued. Cumulative tumor incidences after 216 days following MC injection were 89% in group A, 76% in group B, and 94% in group C. That in non-irradiated control group was 94%. The difference in the tumor incidence between the control and position B was statistically significant, indicating the suppressive effect of the low dose rate irradiation on the process of MC-induced carcinogenesis with an optimum dose rate around 1 mGy/hr. In B6C3F1 mice, although the suppression of tumor incidence was not observed, there was a significant delay in tumor appearance in the irradiated mice between 100-150 days after MC injection. A group of 20 female C57BL/6N mice, 5 weeks old, were exposed to gamma-rays at 0.95 mGy/hr for 5 weeks. Then, they were exposed weekly to 1.8 Gy whole body X-irradiation (300 kVp) for consecutive 4 weeks to induce thymic lymphoma. Another group received only the fractionated irradiation. The first mouse died from thymic lymphoma appeared 89 days after the last irradiation in the group received only the fractionated irradiation, while 110 days in the group combined with the low dose rate irradiation. (author)

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

International Nuclear Information System (INIS)

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

2002-01-01

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

Establishing the irradiation dose for paper decontamination

International Nuclear Information System (INIS)

Moise, Ioan Valentin; Virgolici, Marian; Negut, Constantin Daniel; Manea, Mihaela; Alexandru, Mioara; Trandafir, Laura; Zorila, Florina Lucica; Talasman, Catalina Mihaela; Manea, Daniela; Nisipeanu, Steluta; Haiducu, Maria; Balan, Zamfir

2012-01-01

Museums, libraries and archives are preserving documents that are slowly degrading due to the inherent ageing of the cellulose substrate or to the technological errors of the past (acid paper, iron gall ink). Beside this, large quantities of paper are rapidly damaged by biological attacks following natural disasters and improper storage conditions. The treatment of paper documents with ionizing radiation can be used for mass decontamination of cultural heritage items but conservators and restaurators are still reserved because of the radiation induced degradation. We conducted a study for establishing the dose needed for the effective treatment of paper documents, taking into account the biological burden and the irradiation effects on paper structure. We used physical testing specific to paper industry and less destructive analytical methods (thermal analysis). Our results show that an effective treatment can be performed with doses lower than 10 kGy. Old paper appears to be less affected by gamma radiation than recent paper but the sampling is highly affected by the non-uniform degree of the initial degradation status. The extent of testing for degradation and the magnitude of acceptable degradation should take into account the biological threat and the expected life time of the paper documents. - RESEARCH HIGHLIGHTS: ► For doses <15 kGy, the measurement uncertainty of mechanical properties is higher than the radiation induced degradation. ► The statistics of measuring induced degradation may be improved by testing both mechanical properties and thermal decomposition of paper. ►Because of the large variability of paper samples, testing to only one irradiation dose has no or reduced relevance. ►It was choused for the irradiation of paper items from archives and collections a dose range of 5–7 kGy.

Melanin is Effective Radioprotector against Chronic Irradiation and Low Radiation Doses

International Nuclear Information System (INIS)

Mosse, I.; Plotnikova, S.; Kostrova, L.; Molophei, V.; Dubovic, B.

2001-01-01

Full text: Earlier we found pigment melanin ability to reduce significantly genetic consequences of acute irradiation in animals (drosophila, mice) and cultured human cells and to decrease strongly 'genetic load' accumulated in irradiated populations. The influence of melanin isolated from human hair on genetic effects of chronic irradiation in mice has been investigated. Melanin suspension or distilled water were injected every day into stomach of animals during 1-3 Gy g-irradiation with dose rate 0.007Gy/h. Levels of reciprocal translocations in germ cells were analysed cytologically. Melanin influence on genetic effect of chronic irradiation was shown to be even more effective than that of acute one. Radioadaptive response was used in order to study melanin influence on low radiation dose effect. We have demonstrated adaptive response in mice germ cells and bone marrow cells frequency of chromosomal aberrations in these cells after 0.2+1.5 Gy was about half as much as 1.7 Gy effect. Melanin injection 2 hours before the conditioning dose of 0.2 Gy resulted in the same mutation level as before 1.7 Gy adaptive response was not found. If melanin was applied between the first and second doses, both adaptive reaction and protection led to 4-fold decrease in aberration level. Thus melanin is able to remove completely low radiation dose effect. Complete toxicological tests have been conducted. The pigment melanin is not toxic and does not possess a mutagenic, teratogenic or carcinogenic activity. Melanin could be used in medicine for people protection against genetic consequences of long-term irradiation at low doses. (author)

Effect of low doses gamma-irradiation on yield and nitrogen utilization in potato

International Nuclear Information System (INIS)

Al-Oudat, M.; Sharanek, A.

1998-01-01

Twelve field experiments were conducted in two seasons (1992 and 1993) in three regions of Syria (Damascus, Al-Salamia and Al-Ghab). Tubers of potato (Solanum tuberosum L. var Diamont) were irradiation with gamma-radiation from a 60 Co source, using doses of 0,1,2,3,5 and 10 Gy, at dose rate of 0.15 Gy/min. The irradiated tubers were sown 5-6 days after irradiation, in a randomized complete block design with four replicates and two rates of nitrogen fertilizer (0 and 120 Kg/N/ha). Irradiation and N application significantly increased dry matter production by 24% (for optimal dose) and 38% respectively. The tuber yields were increased by 28.7% for N application and between 13.6 and 19.7 for optimal dose, as a mean for all experiments and regions. Presowing tubers irradiation with 3 Gy. dose also Increased N uptake at harvest by 21.6, 16.6 and 18% for Damascus, Al-Salamia and Al-Ghab respectively. irradiation had negligible effects on N concentration and both Scratch and Vitamin C contents in tubers. (author)

Effects of low doses gamma irradiation on yield and nitrogen utilization in potato

International Nuclear Information System (INIS)

Al-Oudat, M.; Sharanik, A.

1997-12-01

Twelve field experiments were conducted in two seasons (1992 and 1993) in three regions of Syria (Damascus, Al-Salamia and Al-Ghab). Tubers of potato (Solanum tuberosum L. var Diamont) were irradiated with gamma-radiation from a 60 Co source, using doses of 0,1,2,3,5 and 10 Gy, at dose rate of 0.15 Gy/min. The irradiated tubers were sown 5-6 days after irradiation, in a randomized complete block design with four replicates and two rates of nitrogen fertilizer (0 and 120 Kg/N/ha). Irradiation and N application significantly increased dry matter production by 24% (for optimal dose) and 38% respectively. The tuber yields were increased by 28.7% for N application and between 13.6 and 19.7 for optimal dose, as a mean for all experiments and regions. Presowing tubers irradiation with 3 Gy. dose also Increased N uptake at harvest by 21.6, 16.6 and 18% for Damascus, Al-Salamia and Al-Ghab respectively. irradiation had negligible effects on N concentration and both Scratch and Vitamin C contents in tubers. (author)

Shelf-stable food through high dose irradiation

International Nuclear Information System (INIS)

Placek, V.; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M.

2004-01-01

Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO x -containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested

Shelf-stable food through high dose irradiation

Energy Technology Data Exchange (ETDEWEB)

Placek, V. E-mail: pla@ujv.cz; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M

2004-10-01

Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO{sub x}-containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested.

Single Low-Dose Ionizing Radiation Induces Genotoxicity in Adult Zebrafish and its Non-Irradiated Progeny.

Science.gov (United States)

Lemos, J; Neuparth, T; Trigo, M; Costa, P; Vieira, D; Cunha, L; Ponte, F; Costa, P S; Metello, L F; Carvalho, A P

2017-02-01

This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

Dose rate distribution of the GammaBeam: 127 irradiator using MCNPX code

International Nuclear Information System (INIS)

Gual, Maritza Rodriguez; Batista, Adriana de Souza Medeiros; Pereira, Claubia; Faria, Luiz O. de; Grossi, Pablo Andrade

2013-01-01

The GammaBeam - 127 Irradiator is widely used for biological, chemical and medical applications of the gamma irradiation technology using Cobalt 60 radioactive at the Centro de Desenvolvimento da Tecnologia Nuclear CDTN/CNEN, Belo Horizonte, Brazil. The source has maximum activity of 60.000Ci, which is composed by 16 double encapsulated radioactive pencils placed in a rack. The facility is classified by the IAEA as Category II (dry storage facility). The aim of this work is to present a modelling developed to evaluate the dose rates at the irradiation room and the dose distribution at the irradiated products. In addition, the simulations could be used as a predictive tool of dose evaluation in the irradiation facility helping benchmark experiments in new similar facilities. The MCNPX simulated results were compared and validated with radiometric measurements using Fricke and TLDs dosimeters along several positions inside the irradiation room. (author)

Response of mouse lung to irradiation at different dose-rates

International Nuclear Information System (INIS)

Hill, R.P.

1983-01-01

Groups of LAF1 mice were given thoracic irradiation using 60 Co γ-rays at dose-rates of 0.05 Gy/min (LDR) or 1.1 Gy/min (HDR) and the death of the animals was monitored as a function of time. It was found that the time pattern of animal deaths was similar for the two different dose-rates. Dose response curves for animals dying at various times up to 500 days after irradiation were calculated and the LD 50 values determined. The curves for the LD 50 values, plotted as a function of the time at analysis for treatment at HDR or LDR, were essentially parallel to each other but separated by a factor (LDR/HDR) of about 1.8. This indicates that the sparing effect of LDR treatment is the same for deaths occurring during the early pneumonitis phase or during the late fibrotic phase of lung damage. The available information on the response of patients to whole thoracic irradiation, given for either palliation or piror to bone marrow transplantation, suggests that for similar dose-rates to those studied here the ratio (LDR/HDR) is only 1.2 to 1.3. This difference between the animal and human data may reflect the modifying effect of the large doses of cytotoxic drugs used in combination with the irradiation of bone marrow transplant patients

Absorbed dose modeled for a liquid circulating around a Co-60 irradiator

International Nuclear Information System (INIS)

Mangussi, J.

2013-01-01

A model for the distribution of the absorbed dose in a volume of liquid circulating into an active tank containing a Co-60 irradiator is presented. The absorbed dose, the stir process and the liquid recirculation into the active tank are modeled. The absorbed dose for different fractions of the volume is calculated. The necessary irradiation times for the achievement of the required absorbed dose are evaluated. (author)

Pelvic insufficiency fractures associated with radiation atrophy: clinical recognition and diagnostic evaluation

International Nuclear Information System (INIS)

Mumber, M.P.; Greven, K.M.; Haygood, T.M.

1997-01-01

Pelvic bone injuries are infrequent complications of radiotherapy. However, insufficiency fractures in irradiated pelvic bones may be underdetected, particularly in postmenopausal women. We describe the clinical presentation, radiologic evaluation, and course of disease in three patients with postradiation pelvic insufficiency fractures. Differential diagnosis included metastatic disease, tumor recurrence, and second malignancy. Recognition of radiographic features may prevent unnecessary, possibly morbid treatments. (orig.). With 6 figs

Biological changes in experimental animals after irradiation with sublethal doses

Energy Technology Data Exchange (ETDEWEB)

Choi, Dae Seong; Park, Yong Dae; Jin, Chang Hyun; Byun, Myung Woo; Jeong, Il Yun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2008-05-15

The objective of the present study was to investigate general clinical aspects such as weekly body weight and blood changes, and weekly food intake in gamma-irradiated C57BL/6j male mice fed AIN-76A purified rodent diet for 14 weeks. The mice were whole-body irradiated with 0, 2, 4 and 6 Gy of gamma-rays (Gammacell 40 Exactor, {sup 137}Cs, MDS Nordion) at a dose rate of 1.8 {sub c}Gy per second. The mean body weight change of 6 Gy-irradiated mice significantly decreased when compared to that of the non-irradiated control mice. Moreover, high dose of radiation resulted in decreased levels of AST, ALT, but in increased levels of total cholersterol, triglyceride, HDL-C in mice.

Monaco and film dosimetry of 3D CRT, IMRT and VMAT cases in a realistic pelvic prosthetic phantom

Science.gov (United States)

Ade, Nicholas; du Plessis, F. C. P.

2018-04-01

The dosimetry of patients with metallic hip implants during irradiation of pelvic lesions is challenging due to dose distortions caused by implants. This work presents a dosimetric comparison of various multi-field photon-beam dose distributions in the presence of unilateral hip titanium prosthesis (UHTiP) embedded in a unique pelvic phantom made out of water-equivalent nylon slices. The impact of the UHTiP on the accuracy of dose calculations from a Monaco TPS (treatment planning system) using the X-ray voxel Monte Carlo (XVMC) algorithm was benchmarked against measured dose data using Gafchromic EBT3 film. Multi-field beam arrangements including a 4-field box, 5-field 3DCRT (three-dimensional conformal radiation therapy), 6-field IMRT (intensity modulated radiation therapy) and a single-arc VMAT (volumetric modulated arc therapy) plan were set up for 6 MV and 15 MV beams. These plans were generated for the pelvic phantom that contains the prosthesis with film inserted. Compared to Monaco TPS dose calculations, film measurements showed enhanced dose in the prosthesis which was not predicted by Monaco due to its limitation in relative density assignment. The enhanced prosthesis dose increased with increase in beam energy and decreased with the complexity of the treatment plans, with VMAT giving the least escalated dose. The dose increased between 5% and 19% for 6 MV and between 6% and 21% for 15 MV. A gamma index analysis showed that 70-92% of dose points (excluding the prosthesis) were within 3% discrepancy. Increasing the number of treatment fields increases target dose coverage and improves the agreement between film and Monaco. When the relative electron density (RED) in the prosthesis was varied between 3.72 and 15 the dose discrepancy between film and Monaco increased from 30% to 57% for 6 MV and from 30% to 50% for 15 MV. The study indicates that beam weights for fields that pass through the prosthesis should be minimised and its RED must be correct for

The effects of single and fractionated irradiation of the trunk in rats

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 whole trunk irradiation on the development of functional damage was investigated in rats. Rats were restrained without anesthesia such that only the trunk (from clavicle to pelvic girdle) was irradiated with a Cs-137 irradiator at a dose rate of 8.5 Gy/min. Rats received single doses of 9.4, 11.7, 14.1, or 16.4 Gy; or total doses of 11.7, 14.1, 16.4, 18.8, or 21.1 Gy in two equal fractions separated by 4-6 hr. Except for the highest dose in both schedules, there was no lethality; 16.4 Gy reduced survival to 45% and 21.1 Gy in two fractions reduced survival to 77% by day 150. From day 10 to day 150 there was a dose-dependent reduction in weight for both schedules, with the two-dose response displaced from the single dose response by ≅ 6 Gy. A whole-body plethysmograph was used to measure respiration frequency. There was no increase in respiration frequency compared to control animals, except for the highest single dose - 16.4 Gy producing an increase that was manifested from 10 to 150 days. The authors conclude that, in this rat trunk irradiation model, fractionation into two equal doses separated by 4-6 hr produces a sparing effect of ≅ 6 Gy as measured by delay in weight gain (presumably a result of irradiation of the abdomen); and ≥ 6 Gy as measured by survival and increased respiration frequency (a result of irradiation of the thorax)

Carcinoma of the prostate treated by pelvic node dissection, iodine-125 seed implant and external irradiation; a study of rectal complications

Energy Technology Data Exchange (ETDEWEB)

Abadir, R.; Ross, G. Jr.; Weinstein, S.H. (Missouri Univ., Columbia (USA). Hospital and Clinics)

1984-09-01

The University of Missouri-Columbia protocol for localised cancer of the prostate calls for pelvic node dissection, 10 000 cGy at the periphery of the prostate from /sup 125/I and 4000 cGy in 20 fractions to the whole pelvis using supervoltage X-ray therapy. Rectal complications were studied in 104 patients; acute and chronic reactions were defined. During external irradiation 54% did not develop diarrhoea, 43% had mild diarrhoea and 3% had severe diarrhoea. In the chronic stage 77% did not have diarrhoea, 12% had delayed, non-distressing rectal bleeding which did not need specific treatment or needed only simple treatment, 7% had prolonged distressing proctitis and 4% had rectal ulceration or recto-urethral fistula necessitating colostomy. Each of the four patients who had colostomy had an additional aetiological factor (arterial disease, pelvic inflammation, additional radiation, pelvic malignancy or second operation). None of the patients entered in the combined brachytherapy and teletherapy programme, and in whom 0.5 cm space was maintained between the closest seed and the rectal mucosa, developed prolonged proctitis.

The long-term evolution of rectosigmoidal complications in carcinoma of the uterine cervix treated exclusively with irradiation

International Nuclear Information System (INIS)

Pernot, M.; Bey, P.; Stines, J.; Hoffstetter, S.

1985-01-01

We made a retrospective analysis of 216 patients with carcinoma of the uterine cervix treated, from 1973 to 1978, with irradiation alone (177 patients with carcinoma of the cervix and 39 patients with carcinoma of the cervical stump). Of the 177 patients with carcinoma of the cervix, 25 patients were suffering from recto-sigmoidal complications, which in only 3% of them were considered serious. Of the 39 patients with carcinoma of the cervical stump, nine presented complications; in 5,1% the complications were regarded as serious. A good correlation existed between the degree of severity of the rectal symptoms and the Cumulative Maximal Rectal Dose (C.M.R.D.); on the other hand, a correlation could not be ascertained between the severity of the sigmoidal symptoms and the same C.M.R.D. Patients with severe sigmoidal complications, who had developed a stricture, had always received a dose higher than 80 Gy. The most serious rectosigmoidal complications occurred essentially in two situations: in patients in whom following the brachytherapy the central area had been inadequately shielded during the external irradiation. In patients who received a dose of external irradiation in excess of 50 Gy before brachytherapy. In order to prevent these complications, it is advisable to irradiate the pelvic area with doses of 40 to 45 Gy before brachytherapy, and to complete at once the irradiation of the node areas (with central shielding); the dose transmitted to the pelvic wall by brachytherapy must be calculated and included in the total dose administered. The 7 to 12 year follow-up after therapy showed that only 5 patients out of 216 developed severe complications. The crude survival rate of the 3 to 5 year follow-up of patients with carcinoma of the uterine cervix treated exclusively with irradiation between 1973 and 1978 was: T1 83,7 and 77,5%, T2 67,3 and 61,8 %, T3 42,2 and 31,3% [fr

Need for High Radiation Dose (≥70 Gy) in Early Postoperative Irradiation After Radical Prostatectomy: A Single-Institution Analysis of 334 High-Risk, Node-Negative Patients

International Nuclear Information System (INIS)

Cozzarini, Cesare; Montorsi, Francesco; Fiorino, Claudio; Alongi, Filippo; Bolognesi, Angelo; Da Pozzo, Luigi Filippo; Guazzoni, Giorgio; Freschi, Massimo; Roscigno, Marco; Scattoni, Vincenzo; Rigatti, Patrizio; Di Muzio, Nadia

2009-01-01

Purpose: To determine the clinical benefit of high-dose early adjuvant radiotherapy (EART) in high-risk prostate cancer (hrCaP) patients submitted to radical retropubic prostatectomy plus pelvic lymphadenectomy. Patients and Methods: The clinical outcome of 334 hrCaP (pT3-4 and/or positive resection margins) node-negative patients submitted to radical retropubic prostatectomy plus pelvic lymphadenectomy before 2004 was analyzed according to the EART dose delivered to the prostatic bed, <70.2 Gy (lower dose, median 66.6 Gy, n = 153) or ≥70.2 Gy (median 70.2 Gy, n = 181). Results: The two groups were comparable except for a significant difference in terms of median follow-up (10 vs. 7 years, respectively) owing to the gradual increase of EART doses over time. Nevertheless, median time to prostate-specific antigen (PSA) failure was almost identical, 38 and 36 months, respectively. At univariate analysis, both 5-year biochemical relapse-free survival (bRFS) and disease-free survival (DFS) were significantly higher (83% vs. 71% [p = 0.001] and 94% vs. 88% [p = 0.005], respectively) in the HD group. Multivariate analysis confirmed EART dose ≥70 Gy to be independently related to both bRFS (hazard ratio 2.5, p = 0.04) and DFS (hazard ratio 3.6, p = 0.004). Similar results were obtained after the exclusion of patients receiving any androgen deprivation. After grouping the hormone-naive patients by postoperative PSA level the statistically significant impact of high-dose EART on both 5-year bRFS and DFS was maintained only for those with undetectable values, possibly owing to micrometastatic disease outside the irradiated area in case of detectable postoperative PSA values. Conclusion: This series provides strong support for the use of EART doses ≥70 Gy after radical retropubic prostatectomy in hrCaP patients with undetectable postoperative PSA levels.

CONTRASTING DOSE-RATE EFFECTS OF GAMMA-IRRADIATION ON RAT SALIVARY-GLAND FUNCTION

NARCIS (Netherlands)

VISSINK, A; DOWN, JD; KONINGS, AWT

The aim of this study was to investigate the effects of Co-60 irradiation delivered at high (HDR) and low (LDR) dose-rates on rat salivary gland function. Total-body irradiation (TBI; total doses 7.5, 10 and 12.5 Gy) was applied from a Co-60 source at dose-rates of 1 cGy/min (LDR) and 40 cGy/min

Dose Distribution Calculation Using MCNPX Code in the Gamma-ray Irradiation Cell

International Nuclear Information System (INIS)

Kim, Yong Ho

1991-02-01

60 Co-gamma irradiators have long been used for foods sterilization, plant mutation and development of radio-protective agents, radio-sensitizers and other purposes. The Applied Radiological Science Research Institute of Cheju National University has a multipurpose gamma irradiation facility loaded with a MDS Nordin standard 60 Co source (C188), of which the initial activity was 400 TBq (10,800 Ci) on February 19, 2004. This panoramic gamma irradiator is designed to irradiate in all directions various samples such as plants, cultured cells and mice to administer given radiation doses. In order to give accurate doses to irradiation samples, appropriate methods of evaluating, both by calculation and measurement, the radiation doses delivered to the samples should be set up. Computational models have been developed to evaluate the radiation dose distributions inside the irradiation chamber and the radiation doses delivered to typical biolological samples which are frequently irradiated in the facility. The computational models are based on using the MCNPX code. The horizontal and vertical dose distributions has been calculated inside the irradiation chamber and compared the calculated results with measured data obtained with radiation dosimeters to verify the computational models. The radiation dosimeters employed are a Famer's type ion chamber and MOSFET dosimeters. Radiation doses were calculated by computational models, which were delivered to cultured cell samples contained in test tubes and to a mouse fixed in a irradiation cage, and compared the calculated results with the measured data. The computation models are also tested to see if they can accurately simulate the case where a thick lead shield is placed between the source and detector. Three tally options of the MCNPX code, F4, F5 and F6, are alternately used to see which option produces optimum results. The computation models are also used to calculate gamma ray energy spectra of a BGO scintillator at

Pre-irradiation at a low dose-rate blunted p53 response

International Nuclear Information System (INIS)

Takahashi, Akihisa

2002-01-01

We investigated whether chronic irradiation at a low dose-rate interferes with the p53-centered signal transduction pathyway induced by radiation in human cultured cells and C57BL/6N mice. In in vitro experiments, we found that a challenge with X-ray irradiation immediately after chronic irradiation resulted in lower levels of p53 than those observed after the challenge alone in glioblastoma cells (A-172). In addition, the levels of p53-centered apoptosis and its related proteins after the challenge were strongly correlated with the above-mentioned phenomena in squamous cell carcinoma cells (SAS/neo). In in vivo experiments, the accumulation of p53 and Bax, and the induction of apoptosis were observed dose-dependently in mouse spleen at 12 h after a challenge with X-rays (3.0 Gy). However, we found significant suppression of p53 and Bax accumulation and the induction of apoptosis 12 h after challenge irradiation at 3.0 Gy with a high doses-rate following chronic pre-irradiation (1.5 Gy, 0.001 Gy/min). These findings suggest that chronic pre-irradiation suppressed the p53 function through radiation-induced signaling and/or p53 stability. (author)

The clinic and pathologic picture in the lethal dose irradiated ewes

International Nuclear Information System (INIS)

Halagan, J.; Stanikova, A.; Maracek, I.

2004-01-01

The history of clinical symptoms as well as pathologic histological and morphological changes after long/lasting gamma irradiation were estimated in seven clinical healthy ewes. The animals were irradiated continually seven days with totally 6.7 Gy per ewe. Clinically recognizable symptoms of the radiation sickness were observed commencing the 4 th after last dose of irradiation. Sharp increase of the body temperature, heart and respiratory frequency rate as well as apathy, anorexia, arrhythmia, dyspnoe, diarrhea, dehydration, polyuria were prevalent in clinical founding . All of the animals were death in course of seven days after last irradiated dose. The gastrointestinal radiation syndrome was typical evidence of gastrointestinal tract and the general hemorrhagic enhancing of the gamma irradiation damage effects was confirmed. (authors)

Treatment of selected primary gynecologic and pelvic malignancies with 241Americium

International Nuclear Information System (INIS)

Chung, Joyce Y.; Peschel, Richard E.; Kacinski, Barry; Nath, Ravinder; Pourang, Rauman; Roberts, Kenneth; Fischer, Diana; Chambers, Joseph; Schwartz, Peter E.; Wilson, Lynn

1995-01-01

Purpose: To evaluate the efficacy of encapsulated 241 Am in the treatment of primary gynecological malignancies and in previously irradiated patients with recurrent disease in the pelvis. Materials and Methods: Encapsulated 241 Am primarily emits 60keV photons which are effectively shielded by thin layers of high atomic number materials. Dose distributions in water are similar to those produced by Cs-137 photons but with a half-value layer that is considerably less. Cases of 28 patients (12-primary, 16-recurrent) who have been treated with 241 Am at the Yale University School of Medicine since 1986 were retrospectively reviewed. Data concerning dosimetry, disease site, prior treatment, recurrence, disease-free survival, overall survival, and complications were evaluated. Results: Median follow up for the 12 patients with primary gynecological tumors was 19 months (7mo-51mo). There were 6 vulvar, 3 vaginal, 2 cervical and 1 endometrial carcinomas. Median surface dose of 241 Am was 42.2 Gy (23.3Gy-106.6Gy). As part of their initial therapy 11 received pelvic external beam radiation therapy, 6 underwent surgery and 2 received other forms of intracavitary brachytherapy. Of these 12 patients, 11 achieved a complete response (CR) with the duration of CR ranging from 7 to 51 months. Actuarial disease-free survival at 3 years was 66% (S.E.=.16) and actuarial overall survival at 3 years was 91% (S.E.=.08). Median follow up for the 16 patients with recurrent pelvic malignancies was 72 months (20mo-99mo). There were 9 cases of endometrial, 3 vulvar, 3 colorectal, and 1 cervical carinomas. Fifteen of 16 received some form of surgery and radiotherapy prior to their treatment with 241 Am. Median surface dose of 241 Am was 40.3 (17.6Gy-141.7Gy). Of these 16 patients, 10 achieved a CR with the duration of CR ranging from 3 to 88 months. Actuarial disease-free survival at 5 years was 51% (S.E.=.16) and actuarial overall survival at 5 years was 43% (S.E.=.14). Complications were

Identification and dose assessment of irradiated cardamom and cloves by EPR spectrometry

International Nuclear Information System (INIS)

Beshir, W.B.

2014-01-01

The use of electron paramagnetic resonance spectroscopy to accurately distinguish irradiated from unirradiated cardamom and cloves and assesses the absorbed dose to radiation processed cardamom and cloves are examined. The results were successful for identifying both irradiated and unirradiated cardamom and cloves. Additive reirradiation of cardamom and cloves produces reproducible dose–response functions, which can be used to assess the initial dose by back-extrapolation. Third degree polynomial function was used to fit the EPR signal/dose curves. It was found that this 3rd degree polynomial function provides satisfactory results without correction of decay for free radicals. The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over a storage period of almost 8 months. The calculated G-value (The number of radicals per 100 eV of absorbed energy) for cardamom and cloves was found 0.07±0.01 and 0.055±0.01, respectively. - Highlights: • The EPR analysis of cardamom and cloves prove the sample has been irradiated or not. • Dose additive can be used for evaluation of the absorbed dose in cardamom and cloves. • The 3rd polynomial function can be used to fit the data and the estimated dose. • The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over 2 months

Studies on adaptive response of lymphocyte transformation induced by low-dose irradiation

International Nuclear Information System (INIS)

Du Zeji; Su Liaoyuan; Tian Hailin; Zou Huawei

1995-10-01

Human peripheral blood lymphocytes stimulated by mitogen in vitro for 24 h were exposed to low-dose γ-ray irradiation (0.5∼4.0 cGy, adaptive dose). They showed an adaptive response to the inhibition of 3 H-TdR incorporation by subsequent higher acute doses of γ-ray (challenge dose). At the interval of 24 h between adaptive dose and challenge dose, the strongest adaptive response induced by low-dose irradiation was found. It is also found that the response induced by 1.0 cGy of adaptive dose was more obvious than that by other doses and that 3.0 Gy of challenge dose produced the strongest adaptive response. As the challenge doses increased, the adaptive response reduced. (2 figs., 2 tabs.)

Absorbed Dose Measurement in Gonads Menduring Abdominal and Pelvicradiotherapy

OpenAIRE

Sadegh Masoudi; Ali Asghar Yousefi; Somayeh Nourollahi; Fatemeh Noughani

2013-01-01

Two different testicular tissues have to be distinguished in regard to radiation damage: first the seminiferous tubules, corresponding to the sites of spermatogenesis, which are extremely radiosensitive. Second the testosterone secreting Leydig cells, which are considered to be less radiosensitive. This study aims to estimate testicular dose and the associated risks for infertility and hereditary effects from Abdominal and pelvic irradiation. Radiotherapy was simulated on a humanoid phantom u...

Estimation of the absorbed dose in gamma irradiated food containing bone by electron spin resonance spectroscopy

International Nuclear Information System (INIS)

Basfar, A.A.; Abdel Rehim, F.

1997-01-01

The use of electron spin resonance (ESR) spectroscopy to accurately evaluate the absorbed dose to radiationprocessed bones (and thus meats) is examined. The exposure of foodstuffs containing bone to a dose of ionizing radiation results in the formation of long lived free radicals which give rise to characteristics ESR signals. The yield of radicals was found to be proportional to absorbed dose. Additive re-irradiation of previously irradiated bone was used to estimate the absorbed dose in the irradiated chicken bone. Simple non-linear rational equation was found to fit to the data and yields good dose estimates for irradiated bone in the range of doses (1.0 - 5.0 kGy). Decay of the ESR signal intensity was monitored at different dose levels (2.0 and 7.0 kGy) up to 22 days. The absorbed dose in irradiated chicken (2.Om 3.0 and 6.0 kGy) was assessed at 2, 6 and 12 days after irradiation. Relatively good results were obtained when measurements were made within the following days (up to 12 days) after irradiation. The ability of the dose additive method to provide accurate dose assessments is tested here

Irradiation of meningioma: a prototype circumscribed tumor for planning high-dose irradiation of the brain

International Nuclear Information System (INIS)

Friedman, M.

1977-01-01

The purpose of this report is to provide specific data concerning the radiation dose required to destroy meningioma, and to demonstrate that radiation doses much greater than the alleged tolerance dose, can be administered to the brain in some patients. Most meninglomas are not responsive to irradiation, but, some surgically incurable lesions benefit from irradiation with radically high doses to small volumes of tissue. The arrest of 7 of 12 consecutive meningiomas in adults for periods of 2 to 17 years following maximum tumor doses up to 8800 R in 40 days is reported in this paper. All patients, when irradiated, had active tumor in the form of inoperable primary tumor, recurrence, or known postoperative residual tumor. Three of the successful results were achieved with orthovoltage radiation. The incidence of brain damage may be acceptable to the patient when it is related to arrest of tumor growth but he must be forewarned of possible brain damage. The factors influencing the radioresponsiveness of meningioma are: the required tumor lethal dose, histology and vascularity of the tumor, anatomical site in the brain, treatment technique for each tumor site, small size of the treated volume, growth rate of the tumor, displacement of normal brain tissue by tumor, inherent individual variations of tumor and normal tissues, quality of the radiation, and tolerance of normal brain tissues. The role of these factors is discussed in the light of modern radiobiological concepts

Pelvic insufficiency fractures in postmenopausal woman with advanced cervical cancer treated by radiotherapy

International Nuclear Information System (INIS)

Ogino, Ichiro; Okamoto, Naoyuki; Ono, Yoshimi; Kitamura, Tatsuo; Nakayama, Hiroki

2003-01-01

Purpose: To assess the predisposing factors and clinical characteristics of pelvic insufficiency fractures (PIF) in postmenopausal women with pelvic irradiation. Material and methods: A total 335 postmenopausal patients with cervical cancer of the intact uterus treated with radiation therapy between 1983 and 1998 were reviewed. Total external dose was delivered between 45 and 50.4 Gy with parallel opposed anteroposterior portals. Total brachytherapy dose at point A was delivered between 10 and 36 Gy. PIF were diagnosed by bone scintigraphy and confirmed by computed tomography. The cumulative incidence of symptomatic PIF was estimated by actuarial methods. Potential risk factors (age, weight, type II diabetes, delivery, menopause, total external dose, total brachytherapy dose) were assessed. Results: Fifty-seven (17.0%) of 335 patients were diagnosed as having PIF. Forty-seven patients were symptomatic and ten were asymptomatic. Parameters carrying a significant association with PIF were body weight 49 kg or below (P=0.044) in stepwise logistic regression analysis. The cumulative incidence of symptomatic PIF at 5 years was 17.9% calculated by the Kaplan-Meier method. A body weight of 49 kg or below and more than three deliveries were identified as having a significant effect on symptomatic PIF in univariate analysis (P=0.021, P=0.003, log-rank test) and Cox life table regression analysis (P=0.038, P=0.013). Five patients required narcotic agents and eight patients required hospital admission. Conclusions: We should consider reducing the dose contribution to the sacrum and sacroilac joints, without underdosing the tumor, especially in postmenopausal women with many deliveries or low body weight

Late effects of chronic low dose-rate γ-rays irradiation on mice

International Nuclear Information System (INIS)

Tanaka, Satoshi; Sasagawa, Sumiko; Ichinohe, Kazuaki; Matsumoto, Tsuneya; Otsu, Hiroshi; Sato, Fumiaki

2002-01-01

To evaluate late biological effects of chronic low dose-rate radiation, we are conducting two experiments. Experiment 1 - Late effects of chronic low dose-rate g-rays irradiation on SPF mice, using life-span and pathological changes as parameters. Continuous irradiation with g-rays for 400 days was performed using 137 Cs γ-rays at dose-rates of 20 mGy/day, 1 mGy/day and 0.05 mGy/day with accumulated doses equivalent to 8,000 mGy, 400 mGy and 20 mGy, respectively. All mice were kept until they died a natural death. As of 2002 March 31, 3,999 of the total 4,000 mice have died. Preliminary analyses of data show that 20 mGy/day suggested a shortened life span in both sexes. Partial results show that the most common lethal neoplasms in the pooled data of non-irradiated control and irradiated male mice, in order of frequency, were neoplasms of the lymphohematopoietic system, liver, and lung. In female mice, neoplasms of the lymphohematopoietic system, soft tissue, and endocrine system were common. Experiment 2 - Effects on the progeny of chronic low dose-rate g-ray irradiated SPF mice: pilot study, was started in 1999 and is currently in progress. (author)

High dose rate (HDR) and low dose rate (LDR) interstitial irradiation (IRT) of the rat spinal cord

International Nuclear Information System (INIS)

Pop, Lucas A.M.; Plas, Mirjam van der; Skwarchuk, Mark W.; Hanssen, Alex E.J.; Kogel, Albert J. van der

1997-01-01

Purpose: To describe a newly developed technique to study radiation tolerance of rat spinal cord to continuous interstitial irradiation (IRT) at different dose rates. Material and methods: Two parallel catheters are inserted just laterally on each side of the vertebral bodies from the level of Th 10 to L 4 . These catheters are afterloaded with two 192 Ir wires of 4 cm length each (activity 1-2.3 mCi/cm) for the low dose rate (LDR) IRT or connected to the HDR micro-Selectron for the high dose rate (HDR) IRT. Spinal cord target volume is located at the level of Th 12 -L 2 . Due to the rapid dose fall-off around the implanted sources, a dose inhomogeneity across the spinal cord thickness is obtained in the dorso-ventral direction. Using the 100% reference dose (rate) at the ventral side of the spinal cord to prescribe the dose, experiments have been carried out to obtain complete dose response curves at average dose rates of 0.49, 0.96 and 120 Gy/h. Paralysis of the hind-legs after 5-6 months and histopathological examination of the spinal cord of each irradiated rat are used as experimental endpoints. Results: The histopathological damage seen after irradiation is clearly reflected the inhomogeneous dose distribution around the implanted catheters, with the damage predominantly located in the dorsal tract of the cord or dorsal roots. With each reduction in average dose rate, spinal cord radiation tolerance is significantly increased. When the dose is prescribed at the 100% reference dose rate, the ED 50 (induction of paresis in 50% of the animals) for the HDR-IRT is 17.3 Gy. If the average dose rate is reduced from 120 Gy/h to 0.96 or 0.49 Gy/h, a 2.9- or 4.7-fold increase in the ED 50 values to 50.3 Gy and 80.9 Gy is observed; for the dose prescribed at the 150% reference dose rate (dorsal side of cord) ED 50 values are 26.0, 75.5 and 121.4 Gy, respectively. Using different types of analysis and in dependence of the dose prescription and reference dose rate, the �

Serum metabonomics of rats irradiated by low-dose γ-rays

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Ying HE

2014-08-01

Full Text Available Objective　To explore the effect of low-dose γ-rays on the metabolites in rat serum. Methods　Sixteen healthy male SD rats were randomly divided into control group and irradiated group (n=8. The rats in irradiated group were irradiated by 60Co γ-rays with a dose rate of 72mGy/h for 7 days (1 hour per day. At the 7th day after irradiation, blood samples were taken from abdominal aorta to obtain the serum. The metabolic fingerprints of serum were obtained from the two groups of rats, and 1H nuclear magnetic resonance (NMR spectroscopy, principal component analysis (PCA and orthogonal signal correction-partial least squares (OSC-PLS method were used for pattern recognition, and the difference in metabolite profile between two groups was identified by SIMCA-P software. Results　The rat serum 1H NMR spectra revealed a significant difference between control group and irradiated group, the OSC-PLS plots of the serum samples presented marked clustering between two groups. Compared with the control group, the content of lipid, glucose, creatine, glycine/glucose, high density lipoprotein, low density lipoprotein, very low density lipoprotein/low density lipoprotein and unsaturated fatty acid increased, while the content of lactic acid, threonine/lipid, alanine, N-acetyl glycoprotein 1, N-acetyl glycoprotein 2, saturated fatty acid and phosphatidyl choline decreased in irradiated group. Conclusion　Irradiation with low-dose γ-ray could induce changes in metabolites in rat serum, concerning mainly immune function, energy metabolism, carbohydrate metabolism and lipid metabolism. DOI: 10.11855/j.issn.0577-7402.2014.07.02

Pathomorphology of spleen lymphocyte apoptosis in large dose 60Co γ-irradiated mice

International Nuclear Information System (INIS)

Gao Linlu; Cui Yufang; Yang Hong; Xia Guowei; Peng Ruiyun; Gao Yabing; Wang Dewen

2000-01-01

Objective: The aim of the authors was to investigate the pathomorphology changes of spleen lymphocyte apoptosis after 60 Co γ-irradiation. Methods: The mice were irradiated with 6, 9, 12, 15 and 20 Gy of 60 Co γ-rays. At different times after irradiation, the mice were sacrificed and the pathological changes of spleen lymphocyte were observed by light and transmission electron microscopies. Results: Spleen lymphocyte decreased evidently and the peak of apoptosis in spleen lymphocyte was dependent on radiation dose and the time after irradiation. Conclusion: After γ-irradiation with large doses, pathological changes of spleen lymphocyte apoptosis in mice can be divided into obviously different stages. The main causes of death of spleen lymphocytes are different in different dose groups

External cobalt 60 irradiation alone for stage IIB carcinoma of the uterine cervix

International Nuclear Information System (INIS)

Lei, Z.Z.; He, F.Z.

1989-01-01

From 1964 to 1980, 97 patients with Stage IIb carcinoma of cervix uteri were treated by external 60Co irradiation alone. Of these 97 patients, 94 (96.9%) had squamous cell carcinoma. The parametrial extension of the lesion almost reached the pelvic wall in 73.2% and vaginal extension reached to the upper half of vaginal in 24.7% of the patients. A tumor dose of 60 Gy was given to the whole pelvis by a four field technic (opposing parallel AP and lateral portals) in 6-8 weeks. A booster dose of 10 Gy was delivered to the cervix by a pair of reduced opposing parallel AP portals or a perineal portal in a week. The doses delivered were equivalent to the Time-Dose-Fractionation (TDF) value of 110-130 at the center of pelvis and 90-110 in the whole pelvis. The 5-year survival rate for all 97 patients was 56.7%. It was 59.8% when those who died of other diseases were excluded. The prognosis of patients without residual tumor on the cervix and/or vagina was better than that with residual tumor (p less than 0.01). Thirty-seven patients died of cancer (23 died of recurrence, 8 of distant metastases, 2 of both, and 4 were lost before the fifth year). Of these 37 patients, 97.3% died within 3 years after initial treatment. During the radiation treatment, reactions were moderate. Late complications included 19 (19.6%) with mild cystitis and 16 (16.5%) with mild proctitis, 2 (2.7%) developed recto-vaginal fistula. These results were slightly poorer than those using intracavitary and external irradiation or the combination of preoperative irradiation plus surgery. Yet, for patients with extensions nearing the pelvic wall or with contra-indications to surgery or intracavitary radiotherapy, external irradiation alone is still of value

Effect of large dose gamma-ray irradiation on polyimide

International Nuclear Information System (INIS)

Morita, Yohsuke; Watanabe, Kiyoshi; Yagyu, Hideki.

1988-01-01

In the radiation environment of atomic energy, space and so on, with the heightening of the performance of equipment, the organic materials having the radiation resistance up to several hundreds MGy have been demanded. Polyimide is one of a small number of the polymers which are considered to be applicable to such environment. However, actually the characteristics as the insulator for such large dose radiation environment have not been sufficiently verified. In this study, the gamma-ray of as large dose as 100 MGy was irradiated on the polyimides having different chemical structure in the air and in nitrogen, and the change of their mechanical and electrical characteristics was elucidated, at the same time, the structural change was examined. The four kinds of polyimides used for the experiment were three kinds of thermosetting type and thermoplastic polyether imide. Co-60 gamma-ray was irradiated at the dose rate of 17 kGy/h at room temperature. The tensile properties, volume resistivity, dielectric tangent, gel fraction, glass transition temperature and IR spectra were examined. In the air, the characteristics lowered by large dose irradiation due to the severance of main chains. In nitrogen, the deterioration was extremely slight, and cross-linking occurred. (K.I.)

Marrow toxicity of fractionated vs. single dose total body irradiation is identical in a canine model

International Nuclear Information System (INIS)

Storb, R.; Raff, R.F.; Graham, T.; Appelbaum, F.R.; Deeg, H.J.; Schuening, F.G.; Shulman, H.; Pepe, M.

1993-01-01

The authors explored in dogs the marrow toxicity of single dose total body irradiation delivered from two opposing 60 Co sources at a rate of 10 cGy/min and compared results to those seen with total body irradiation administered in 100 cGy fractions with minimum interfraction intervals of 6 hr. Dogs were not given marrow transplants. They found that 200 cGy single dose total body irradiation was sublethal, with 12 of 13 dogs showing hematopoietic recovery and survival. Seven of 21 dogs given 300 cGy single dose total body irradiation survived compared to 6 of 10 dogs given 300 cGy fractionated total body irradiation. One of 28 dogs given 400 cGy single dose total body irradiation survived compared to none of six given fractionated radiation. With granulocyte colony stimulating factor (GCSF) administered from day 0-21 after 400 cGy total body irradiation, most dogs survived with hematological recovery. Because of the almost uniform success with GCSF after 400 cGy single dose total body irradiation, a study of GCSF after 400 cGy fractionated total body irradiation was deemed not to be informative and, thus, not carried out. Additional comparisons between single dose and fractionated total body irradiation were carried out with GCSF administered after 500 and 600 cGy of total body irradiation. As with lower doses of total body irradiation, no significant survival differences were seen between the two modes of total body irradiation, and only 3 of 26 dogs studied survived with complete hematological recovery. Overall, therefore, survival among dogs given single dose total body irradiation was not different from that of dogs given fractionated total body irradiation (p = .67). Similarly, the slopes of the postirradiation declines of granulocyte and platelet counts and the rates of their recovery in surviving dogs given equal total doses of single versus fractionated total body irradiation were indistinguishable. 24 refs., 3 figs., 2 tabs

Effects of low dose rate irradiation on induction of myeloid leukemia in mice

International Nuclear Information System (INIS)

Furuse, Takeshi

1999-01-01

We investigated the induction of myeloid leukemia and other kinds of neoplasias in C3H male mice irradiated at several dose rate levels. We compared the incidence of neoplasias among these groups, obtained dose and dose rate effectiveness factors (DDREF) for myeloid leukemia. C3H/He male mice were exposed to whole body gamma-ray irradiation at 8 weeks of age. All mice were maintained for their entire life span and teh pathologically examined after their death. Radiation at a high dose-rate of 882 mGy/min (group H), a medium dose-rate of 95.6 mGy/min (group M), and low dose-rates of 0.298 mGy/min (group L-A), 0.067 mGy/min (group L-B) or 0.016 mGy/min (group L-C) were delivered from 137 Cs sources. The mice in group L were irradiated continuously for 22 hours daily up to total doses of 1, 2, 3, 4, 10 Gy over a period of 3 days to 200 days. As for the induction of neoplasias, myeloid leukemia developed significantly more frequently in irradiated groups than in unirradiated groups. The time distribution of mice dying from myeloid leukemia did not show a difference between groups H and L. The incidence of myeloid leukemia showed a greater increase in the high dose-rate groups than in the low and medium dose-rate groups in the dose range over 2 Gy, it also showed significant increases in the groups irradiated with 1 Gy of various dose rate, but the difference between these groups was not clear. These dose effect curves had their highest values on each curve at about 3 Gy. We obtained DDREF values of 2-3 by linear fittings for their dose response curves of dose ranges in which leukemia incidences were increasing. (author)

Inverse dose-rate-effects on the expressions of extra-cellular matrix-related genes in low-dose-rate γ-ray irradiated murine cells

International Nuclear Information System (INIS)

Sugihara, Takashi; Tanaka, Kimio; Oghiso, Yoichi; Murano, Hayato

2008-01-01

Based on the results of previous microarray analyses of murine NIH3T3/PG13Luc cells irradiated with continuous low-dose-rate (LDR) γ-ray or end-high-dose-rate-irradiations (end-HDR) at the end of the LDR-irradiation period, the inverse dose-rate-effects on gene expression levels were observed. To compare differences of the effects between LDR-irradiation and HDR-irradiation, HDR-irradiations at 2 different times, one (ini-HDR) at the same time at the start of LDR-irradiation and the other (end-HDR), were performed. The up-regulated genes were classified into two types, in which one was up-regulated in LDR-, ini-HDR-, and end-HDR irradiation such as Cdkn1a and Ccng1, which were reported as p53-dependent genes, and the other was up-regulated in LDR- and ini-HDR irradiations such as pro-collagen TypeIa2/Colla2, TenascinC/Tnc, and Fibulin5/Fbln5, which were reported as extra-cellular matrix-related (ECM) genes. The time dependent gene expression patterns in LDR-irradiation were also classified into two types, in which one was an early response such as in Cdkn1a and Ccng1 and the other was a delayed response such as the ECM genes which have no linearity to total dose. The protein expression pattern of Cdkn1a increased dose dependently in LDR- and end-HDR-irradiations, but those of p53Ser15/18 and MDM2 in LDR-irradiations were different from end-HDR-irradiations. Furthermore, the gene expression levels of the ECM genes in embryonic fibroblasts from p53-deficient mice were not increased by LDR- and end-HDR-irradiation, so the delayed expressions of the ECM genes seem to be regulated by p53. Consequently, the inverse dose-rate-effects on the expression levels of the ECM genes in LDR- and end-HDR-irradiations may be explained from different time responses by p53 status. (author)

Prophylactic irradiation of para-aortic lymph nodes in carcinoma of the uterine cervix

International Nuclear Information System (INIS)

Chatani, M.; Matayoshi, Y.; Masaki, N.; Narumi, Y.; Teshima, T.; Inoue, T.

1995-01-01

For assessment of the advantages and side effects of para-aortic lymph nodes irradiation under the evaluation by computer tomography, a prospective randomized study was started in 1986. The results for survival, local control and late complications are presented in the following. From November 1986 to October 1990, 93 patients with cervical carcinoma were randomly allocated for treatment with either pelvic irradiation (pelvic group) or pelvic plus para-aortic lymph nodes irradiation (para-aortic group). Thirty-six patients underwent external irradiation and intracavitary therapy (RT arm) and 57 patients, extended radical hysterectomy and external irradiation (OP-RT arm). Para-aortic lymph nodes irradiation delivered 45 Gy in 1.8 Gy per day for 5 days per week through anterior-posterior fields. The 3-year cause specific survival rates were para-aortic group: 57% and pelvic group: 89% in RT arm group, and para-aortic group: 70% and pelvic group: 86% in OP-RT arm group. Differences for the 2 groups in each treatment arm were not significant. In pelvic failure, para-aortic lymph nodes metastases and distant metastases showed no statistically significant differences for the 2 groups in each treatment arm. In the para-aortic group, complications were more frequent than in the pelvic group (13/45 vs. 2/48, p [de

Effect of Gamma Irradiation Doses on Some Chemical Characteristics of Cotton Seed Oil

International Nuclear Information System (INIS)

Saleh, O.I.

2011-01-01

Cotton Seeds c.v. Giza 85 (Gossypium hirsutum L.) were exposed to gamma irradiation doses of 0.5, 1.0 and 1.5 kGy to improve some chemical characteristics of cotton seed oil i.e. saturated and unsaturated fatty acids, gossypol and βsitosterol that were bound oil. The presented study showed that, the saturated fatty acids; lauric, palmitic and stearic increased when the cotton seeds were exposed to gamma irradiation doses of 0.5 up to 1.5 kGy, On the other hand, arachidic acid content decreased in all the irradiated treatments compared with untreated cotton seed. The unsaturated fatty acid oleic was increased in irradiated cotton seed samples compared with untreated one, while linoleic, the major unsaturated fatty acid decreased in irradiated cotton seed oil than untreated seeds. Gossypol and βsitosterol, bound oil, in irradiated cotton seeds increased gradually with gamma irradiated doses compared with untreated control samples

Application of accelerated evaluation method of alteration temperature and constant dose rate irradiation on bipolar linear regulator LM317

International Nuclear Information System (INIS)

Deng Wei; Wu Xue; Wang Xin; Zhang Jinxin; Zhang Xiaofu; Zheng Qiwen; Ma Wuying; Lu Wu; Guo Qi; He Chengfa

2014-01-01

With different irradiation methods including high dose rate irradiation, low dose rate irradiation, alteration temperature and constant dose rate irradiation, and US military standard constant high temperature and constant dose rate irradiation, the ionizing radiation responses of bipolar linear regulator LM317 from three different companies were investigated under the operating and zero biases. The results show that compared with constant high temperature and constant dose rate irradiation method, the alteration temperature and constant dose rate irradiation method can not only very rapidly and accurately evaluate the dose rate effect of three bipolar linear regulators, but also well simulate the damage of low dose rate irradiation. Experiment results make the alteration temperature and constant dose rate irradiation method successfully apply to bipolar linear regulator. (authors)

Medical irradiation and the use of the ''effective dose equivalent'' concept

International Nuclear Information System (INIS)

Persson, B.R.R.

1980-01-01

The aim of this paper is to demonstrate the use of the effective dose for all kinds of medical irradiation. In order to estimate the 'somatic effective dose' the weighting factors recommended by ICRP 26 have been separated into those for somatic effects and for genetic effects. Calculation of the effective dose in diagnostic radiology procedures must consider the various technical parameters which determine the absorbed dose in the various organs, i.e. beam quality, typical entrance dose and the number of films of each view. Knowledge about these parameters is not always well established and therefore the effective dose estimates are very uncertain. The average dose absorbed by various organs in the case of administration of radionuclides to the body depends to a much higher degree on biological parameters than in the case of external irradiation. In contrast to the variability and lack of reliability of biological data, the physical methods for internal dose calculation are quite elaborate. However, these methods have to be extended to involve the target dose from the radioactivity distributed within the remaining parts of the body. An attempt was made to estimate the somatic effective dose for the most common diagnostic X-ray and nuclear medicine procedures. This would make it possible to compare the risk of X-ray and nuclear medicine techniques on a more equitable basis. The collective effective dose from medical irradiation is estimated for various countries on the basis of reported statistical data. (H.K.)

Dose rate and total dose dependence of the 1/f noise performance of a GaAs operational amplifier during irradiation

International Nuclear Information System (INIS)

Hiemstra, D.M.

1995-01-01

A pictorial of a sectioned view of the torus of the International Thermonuclear Experimental Reactor (ITER) is shown. Maintenance and inspection of the reactor are required to be performed remotely. This is due to the high gamma radiation environment in vessel during inspection and maintenance activities. The custom GaAs operational amplifier is to be used to readout sensors on the in-vessel manipulator and inspection equipment. The gamma dose rate during maintenance and inspection is anticipated to be 3 Mrad(GaAs)/hour. Here, dose rate and total dose dependence of the 1/f noise performance of a custom GaAs MESFET operational amplifier during irradiation are presented. Dose rate dependent 1/f noise degradation during irradiation is believed to be due to electron trapping in deep levels, enhanced by backgating and shallow traps excited during irradiation. The reduction of this affect with accumulated total dose is believed to be due a reduction of deep level site concentration associated with substitutional oxygen. Post irradiation 1/f noise degradation is also presented.The generation-recombination noise observed post irradiation can be attributed to the production of shallow traps due to ionizing radiation

Laparoscopic pelvic sling placement facilitates optimum therapeutic radiotherapy delivery in the management of pelvic malignancy.

LENUS (Irish Health Repository)

Joyce, M

2012-02-01

BACKGROUND: Radiotherapy has a significant role in the management of pelvic malignancies. However, the small intestine represents the main dose limiting organ. Invasive and non-invasive mechanical methods have been described to displace bowel out of the radiation field. We herein report a case series of laparoscopic placement of an absorbable pelvic sling in patients requiring pelvic radiotherapy. METHODS: Six patients were referred to our minimally invasive unit. Four patients required radical radiotherapy for localised prostate cancer, one was scheduled for salvage localised radiotherapy for post-prostatectomy PSA progression and one patient required adjuvant radiotherapy post-cystoprostatectomy for bladder carcinoma. All patients had excessive small intestine within the radiation fields despite the use of non-invasive displacement methods. RESULTS: All patients underwent laparoscopic mesh placement, allowing for an elevation of small bowel from the pelvis. The presence of an ileal conduit or previous surgery did not prevent mesh placement. Post-operative planning radiotherapy CT scans confirmed displacement of the small intestine allowing all patients to receive safely the planned radiotherapy in terms of both volume and radiation schedule. CONCLUSION: Laparoscopic mesh placement represents a safe and efficient procedure in patients requiring high-dose pelvic radiation, presenting with unacceptable small intestine volume in the radiation field. This procedure is also feasible in those that have undergone previous major abdominal surgery.

Cecal rupture after continent ileocecal urinary diversion during total pelvic exenteration

International Nuclear Information System (INIS)

Brand, E.

1991-01-01

Continent ureteral diversion at the time of pelvic exenteration avoids an external appliance and allows patients to retain bladder reservoir function. The technical difficulty of this procedure requires meticulous attention to operative and perioperative care, particularly after pelvic irradiation. A patient with recurrent stage IIIB carcinoma of the cervix underwent total pelvic exenteration with reconstructive procedures including low rectal anastomosis, neovagina formation, and ileocecal (Indiana) continent diversion. Early catheterization of the reservoir began 2 weeks postoperatively. One week later cecal rupture occurred, not related to suture line (technical) failure. Because of the high wall tension and reduced compliance in the irradiated cecum, the authors do not recommend catheterization of the urinary reservoir before 4-6 weeks. In order for continent diversion to become the standard diversion in exenteration patients, the major complication rate must remain comparable to that of noncontinent diversion

Overview of Radiosensitivity of Human Tumor Cells to Low-Dose-Rate Irradiation

International Nuclear Information System (INIS)

Williams, Jerry R.; Zhang Yonggang; Zhou Haoming; Gridley, Daila S.; Koch, Cameron J.; Slater, James M.; Little, John B.

2008-01-01

Purpose: We compared clonogenic survival in 27 human tumor cell lines that vary in genotype after low-dose-rate (LDR) or high-dose rate (HDR) irradiation. We measured susceptibility to LDR-induced redistribution in the cell cycle in eight of these cell lines. Methods and Materials: We measured clonogenic survival after up to 96 hours of LDR (0.25 Gy/h) irradiation. We compared these with clonogenic survival after HDR irradiation (50 Gy/h). Using flow cytometry, we measured LDR-induced redistribution as a function of time during LDR irradiation in eight of these cell lines. Results: Coefficients that describe clonogenic survival after both LDR and HDR irradiation segregate into four radiosensitivity groups that associate with cell genotype: mutant (mut)ATM, wild-type TP53, mutTP53, and an unidentified gene in radioresistant glioma cells. The LDR and HDR radiosensitivity correlates at lower doses (∼2 Gy HDR, ∼6 Gy LDR), but not at higher doses (HDR > 4 Gy; LDR > 6 Gy). The rate of LDR-induced loss of clonogenic survival changes at approximately 24 hours; wild-type TP53 cells become more resistant and mutTP53 cells become more sensitive. Redistribution induced by LDR irradiation also changes at approximately 24 hours. Conclusions: Radiosensitivity of human tumor cells to both LDR and HDR irradiation is genotype dependent. Analysis of coefficients that describe cellular radiosensitivity segregates 27 cell lines into four statistically distinct groups, each associating with specific genotypes. Changes in cellular radiosensitivity and redistribution in the cell cycle are strongly time dependent. Our data establish a genotype-dependent time-dependent model that predicts clonogenic survival, explains the inverse dose-rate effect, and suggests possible clinical applications

Dose response of artificial irradiation of fluvial sediment sample for ESR dating

International Nuclear Information System (INIS)

Liu Chunru; Yin Gongming; Gao Lu; Li Jianping; Han Fei; Lin Min

2011-01-01

ESR dating samples need be irradiated to obtain dose response curve and the equivalent dose. The artificial dose rate is about 1 x 10 -1 -1 x 10 2 Gy/min, whereas the natural dose rate is about 3 Gy/ka. Therefore, one must be sure whether the much higher artificial dose rate is suitable for the ESR dating study. In this paper, we use different artificial dose rate to irradiate the same fluvial sample and measure the quartz Al centre ESR signal under the same conditions. The dose response curves are compared, in an attempt to gain a preliminary knowledge on that problem and build a good foundation for our ESR dating studies on fluvial samples. (authors)

Lipid peroxidation in microsomes of murine bone marrow after low-dose γ-irradiation

International Nuclear Information System (INIS)

Schwenke, K.; Coslar, S.; Muehlensiepen, H.; Altman, K.I.; Feinendegen, L.E.

1994-01-01

The principal aim of the study was to investigate the effect of low-dose γ-irradiation on lipid peroxidation (LPO) in murine bone marrow. To this end, the degree of LPO in suspensions of microsomes of murine bone marrow cells (BMC) was determined in terms of malondialdehyde (MDA) formation after whole-body or in vitro exposure to various doses of γ-radiation. These effects were compared to some extent with similar effects in liver and spleen preparations. As to the effect of γ-irradiation on LPO in BMC, the response depends on the dose level and on whether whole-body or in vitro exposures are involved. Whole-body irradiation did not result in an increase in LPO in BMC microsomes, even at such high doses as 15 Gy, although hepatic microsomes showed a marked increase. In contrast, in vitro irradiation of BMC microsomes with 0.1, 10 and 50 Gy brought about an increase in LPO. This increase was already significant (P < 0.05) at 0.1 Gy following a post-irradiation incubation and substantial at 50 Gy, even without subsequent incubation. The results show that low doses of γ-irradiation are able to induce an elevation of LPO in murine BMC microsomes, but only after in vitro irradiation. In the case of whole-body irradiation cellular radical scavengers and other metabolic reactions may prevent a measurable increase in LPO. This is partly illustrated by the case of vitamin-E deficiency, where a substantial increase in LPO in BMC microsomes is observed even without γ-irradiation in comparison with euvitaminotic mice because normally occurring radicals are not scavenged sufficiently. (orig.)

Gamma-irradiated onions as a biological indicator of radiation dose

International Nuclear Information System (INIS)

Vaijapurkar, S.G.; Agarwal, Deepshikha; Chaudhuri, S.K.; Ram Senwar, Kana; Bhatnagar, P.K.

2001-01-01

Post-irradiation identification and dose estimation are required to assess the radiation-induced effects on living things in any nuclear emergency. In this study, radiation-induced morphological/cytological changes i.e., number of root formation and its length, shooting length, reduction in mitotic index, micronuclei formation and chromosomal aberrations in the root tip cells of gamma-irradiated onions at lower doses (50-2000 cGy) are reported. The capabilities of this biological species to store the radiation-induced information are also studied

Radiation effect and response of DNA synthesis in lymphocytes induced by low dose irradiation

International Nuclear Information System (INIS)

Zhao Yujie; Su Liaoyuan; Zou Huawei; Kong Xiangrong

1999-01-01

The ability of DNA synthesis in lymphocytes were measured by using 3 H-TdR incorporation method. This method was used to observe the damage of lymphocytes irradiated by several challenge doses (0.5-0.8 Gy) and adaptive response induced by previous low dose irradiation. The results show that DNA synthesis was inhibited by challenge dose of radiation and was adapted by previous 0.048 Gy irradiation

Dose rate determinations in the Portuguese Gamma Irradiation Facility: Monte Carlo simulations and measurements

International Nuclear Information System (INIS)

Oliveira, C.; Salgado, J.; Ferro de Carvalho, A.

2000-01-01

A simulation study of the Portuguese Gamma Irradiation Facility, UTR, has been carried out using the MCNP code. The work focused on the optimisation of the dose distribution inside the irradiation cell, dose calculations inside irradiated samples and dose calculations in critical points for protection purposes. Calculations were carried out at points inside and outside the irradiation cell, where different behaviour was expected (distance from the source, radiation absorption and scattering in irradiator structure and walls). The contributions from source, irradiator structure, sample material, carriers, walls, ceiling and floor to the photon spectra and air kerma at those points are reported and discussed. Air kerma measurements were also carried out using an ionisation chamber. Good agreement was found between experimental and calculated air kermas. (author)

Quality of fresh-cut Iceberg lettuce and spinach irradiated at doses up to 4 kGy

International Nuclear Information System (INIS)

Fan Xuetong; Guan Wenqiang; Sokorai, Kimberly J.B.

2012-01-01

Fresh-cut Iceberg lettuce packaged in modified atmosphere packages and spinach in perforated film bags were irradiated with gamma rays at doses of 0, 1, 2, 3, and 4 kGy. After irradiation, the samples were stored for 14 days at 4 °C. O 2 levels in the packages of fresh-cut Iceberg lettuce decreased and CO 2 levels increased with increasing radiation dose, suggesting that irradiation increased respiration rates of lettuce. Tissue browning of irradiated cut lettuce was less severe than that of non-irradiated, probably due to the lower O 2 levels in the packages. However, samples irradiated at 3 and 4 kGy had lower maximum force and more severe sogginess than the non-irradiated control. In addition, ascorbic acid content of irradiated lettuce was 22–40% lower than the non-irradiated samples after 14 days of storage. The visual appearance of spinach was not affected by irradiation even at a dose of 4 kGy. Consumer acceptance suggested that more people would dislike and would not buy spinach that was treated at 3 and 4 kGy as compared to the non-irradiated sample. Overall, irradiation at doses of 1 and 2 kGy may be employed to enhance microbial safety of fresh-cut Iceberg lettuce and spinach while maintaining quality. - Highlights: ▶ Headspace composition in the modified atmosphere packages of cut lettuce was affected by irradiation. ▶ Fresh-cut lettuce in adapted atmosphere could tolerate 1 or 2 kGy rays without quality deterioration in look and texture. ▶ Lettuce irradiated at doses higher than 2 kGy developed sogginess. ▶ Irradiated spinach maintained a good appearance at doses of 3 and 4 kGy. ▶ Higher doses (3 and 4 kGy) of radiation decreased consumers' likingness and purchase intent of irradiated spinach.

Sterility and Sexual Competitiveness of Tapachula-7 Anastrepha ludens Males Irradiated at Different Doses.

Science.gov (United States)

Orozco-Dávila, Dina; Adriano-Anaya, Maria de Lourdes; Quintero-Fong, Luis; Salvador-Figueroa, Miguel

2015-01-01

A genetic sexing strain of Anastrepha ludens (Loew), Tapachula-7, was developed by the Mexican Program Against Fruit Flies to produce and release only males in programs where the sterile insect technique (SIT) is applied. Currently, breeding are found at a massive scale, and it is necessary to determine the optimum irradiation dose that releases sterile males with minimum damage to their sexual competitiveness. Under laboratory and field conditions, we evaluated the effects of gamma irradiation at doses of 0, 20, 40, 60 and 80 Gy on the sexual competitiveness of males, the induction of sterility in wild females and offspring survivorship. The results of the study indicate that irradiation doses have a significant effect on the sexual behavior of males. A reduction of mating capacity was inversely proportional to the irradiation dose of males. It is estimated that a dose of 60 Gy can induce more than 99% sterility in wild females. In all treatments, the degree of offspring fertility was correlated with the irradiation dose of the parents. In conclusion, the results of the study indicate that a dose of 60 Gy can be applied in sterile insect technique release programs. The application of this dose in the new genetic sexing strain of A. ludens is discussed.

Proton and photon absorbed-dose conversion coefficients for embryo and foetus from top-down irradiation geometry

International Nuclear Information System (INIS)

Chen, J.

2007-01-01

Absorbed-dose conversion coefficients are calculated for the embryo of 8 weeks and the foetus of 3, 6 or 9 months when the mother's body is exposed to protons and photons from top-down (TOP) direction. It provides data sets in addition to other standard irradiation geometries published previously. The TOP-irradiation geometry is considered here, because high-energy particles are often peaked from the TOP direction onboard aircraft. The results show that absorbed-doses from high-energy particles could be underestimated significantly if isotropic (ISO) irradiation geometry is assumed. For protons of 100 GeV, absorbed-doses from TOP irradiation are ∼2.3-2.9 times higher than the doses from ISO irradiation for different foetal ages. For 10 GeV photons, foetal doses from TOP irradiation are ∼6.8-12 times higher than the doses from ISO irradiation. The coefficients from TOP-irradiation geometry are given in wide energy ranges, from 100 MeV to 100 GeV for protons and from 50 V to 10 GeV for photons. They can, therefore, be used in various applications whenever exposure from the TOP-irradiation direction is concerned. (authors)

Analysis of gamma irradiator dose rate using spent fuel elements with parallel configuration

International Nuclear Information System (INIS)

Setiyanto; Pudjijanto MS; Ardani

2006-01-01

To enhance the utilization of the RSG-GAS reactor spent fuel, the gamma irradiator using spent fuel elements as a gamma source is a suitable choice. This irradiator can be used for food sterilization and preservation. The first step before realization, it is necessary to determine the gamma dose rate theoretically. The assessment was realized for parallel configuration fuel elements with the irradiation space can be placed between fuel element series. This analysis of parallel model was choice to compare with the circle model and as long as possible to get more space for irradiation and to do manipulation of irradiation target. Dose rate calculation were done with MCNP, while the estimation of gamma activities of fuel element was realized by OREGEN code with 1 year of average delay time. The calculation result show that the gamma dose rate of parallel model decreased up to 50% relatively compared with the circle model, but the value still enough for sterilization and preservation. Especially for food preservation, this parallel model give more flexible, while the gamma dose rate can be adjusted to the irradiation needed. The conclusion of this assessment showed that the utilization of reactor spent fuels for gamma irradiator with parallel model give more advantage the circle model. (author)

Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation; Etude clinique et symptomatologique chez le porc soumis a une irradiation gamma totale a dose letale

Energy Technology Data Exchange (ETDEWEB)

Vaiman, M; Guenet, J -L; Maas, J; Nizza, P

1966-05-01

Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of {gamma} radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [French] Les auteurs rapportent les resultats d'une etude clinique et hematologique chez des porcs de race corse irradies in toto a dose sensiblement letale. Le but de cette etude etait de connaitre l'evolution du syndrome aigu d'irradiation chez le porc et de permettre ainsi le developpement d'experimentations ulterieures, en particulier dans le domaine therapeutique. La dose delivree etait de 285 rad (en dose absorbee au niveau du plan median vertical anteroposterieur. L'etude a porte essentiellement: 1. Sur les modifications cyclo-hematologiques du sang circulant immediatement apres l'irradiation, pour les differentes lignees cellulaires; l'evolution de ces modifications a ete notee jusqu'a la mort; 2. Sur les modifications de la cytologie medullaire apres irradiation (evolution du myelogramme et essai d'evaluation de la cellularite de la moelle osseuse);: 3. Sur les signes cliniques, d'ailleurs tres discrets, observes chez les porcs apres irradiation. (auteurs)

Clinical and symptomatological study of pigs subjected to a lethal dose of integral gamma irradiation; Etude clinique et symptomatologique chez le porc soumis a une irradiation gamma totale a dose letale

Energy Technology Data Exchange (ETDEWEB)

Vaiman, M.; Guenet, J.-L.; Maas, J.; Nizza, P

1966-05-01

Results are reported from a clinical and haematological study on a Corsican species of pigs wholly exposed to an approximately lethal dose of {gamma} radiation. The aim of this work was to examine the changes in the irradiation syndrome of irradiation for pigs to make it thus possible to devise further experiments, in particular in the therapeutic field. The dose received was 285 rads (measured as the absorption in the vertical antero-posterior medial plane). Data are presented on cyto-haematological changes in the blood circulating immediately after irradiation, and followed up to death, and changes in the medullary cytology after irradiation. The clinical picture of lethal radiation injury in swine is described. (authors) [French] Les auteurs rapportent les resultats d'une etude clinique et hematologique chez des porcs de race corse irradies in toto a dose sensiblement letale. Le but de cette etude etait de connaitre l'evolution du syndrome aigu d'irradiation chez le porc et de permettre ainsi le developpement d'experimentations ulterieures, en particulier dans le domaine therapeutique. La dose delivree etait de 285 rad (en dose absorbee au niveau du plan median vertical anteroposterieur. L'etude a porte essentiellement: 1. Sur les modifications cyclo-hematologiques du sang circulant immediatement apres l'irradiation, pour les differentes lignees cellulaires; l'evolution de ces modifications a ete notee jusqu'a la mort; 2. Sur les modifications de la cytologie medullaire apres irradiation (evolution du myelogramme et essai d'evaluation de la cellularite de la moelle osseuse);: 3. Sur les signes cliniques, d'ailleurs tres discrets, observes chez les porcs apres irradiation. (auteurs)

Treatment of selected primary gynecologic and pelvic malignancies with {sup 241}Americium

Energy Technology Data Exchange (ETDEWEB)

Chung, Joyce Y; Peschel, Richard E; Kacinski, Barry; Nath, Ravinder; Pourang, Rauman; Roberts, Kenneth; Fischer, Diana; Chambers, Joseph; Schwartz, Peter E; Wilson, Lynn

1995-07-01

Purpose: To evaluate the efficacy of encapsulated {sup 241}Am in the treatment of primary gynecological malignancies and in previously irradiated patients with recurrent disease in the pelvis. Materials and Methods: Encapsulated {sup 241}Am primarily emits 60keV photons which are effectively shielded by thin layers of high atomic number materials. Dose distributions in water are similar to those produced by Cs-137 photons but with a half-value layer that is considerably less. Cases of 28 patients (12-primary, 16-recurrent) who have been treated with {sup 241}Am at the Yale University School of Medicine since 1986 were retrospectively reviewed. Data concerning dosimetry, disease site, prior treatment, recurrence, disease-free survival, overall survival, and complications were evaluated. Results: Median follow up for the 12 patients with primary gynecological tumors was 19 months (7mo-51mo). There were 6 vulvar, 3 vaginal, 2 cervical and 1 endometrial carcinomas. Median surface dose of {sup 241}Am was 42.2 Gy (23.3Gy-106.6Gy). As part of their initial therapy 11 received pelvic external beam radiation therapy, 6 underwent surgery and 2 received other forms of intracavitary brachytherapy. Of these 12 patients, 11 achieved a complete response (CR) with the duration of CR ranging from 7 to 51 months. Actuarial disease-free survival at 3 years was 66% (S.E.=.16) and actuarial overall survival at 3 years was 91% (S.E.=.08). Median follow up for the 16 patients with recurrent pelvic malignancies was 72 months (20mo-99mo). There were 9 cases of endometrial, 3 vulvar, 3 colorectal, and 1 cervical carinomas. Fifteen of 16 received some form of surgery and radiotherapy prior to their treatment with {sup 241}Am. Median surface dose of {sup 241}Am was 40.3 (17.6Gy-141.7Gy). Of these 16 patients, 10 achieved a CR with the duration of CR ranging from 3 to 88 months. Actuarial disease-free survival at 5 years was 51% (S.E.=.16) and actuarial overall survival at 5 years was 43% (S

γ-ray induced chromosome aberration in rabbit peripheral blood lymphocytes irradiated in partial and whole body and decline of aberration rate with time post-exposure

International Nuclear Information System (INIS)

Zhang Lianzhen; Deng Zhicheng; Wang Haiyan

1997-01-01

Te author presents the results of study on 60 Co γ-ray induced chromosome aberration in rabbits peripheral blood lymphocytes irradiated in partial and whole body and the aberration rate decrease with the time of post-exposure. The experiments included 5 groups, it was whole-body exposure group, partial-body exposure (abdomen and pelvic cavity) group, blood irradiation group in vitro and control group respectively. Radiation dose was 3.0 Gy delivered at rate of 0.5 Gy/min. The results show that it was no significant differences between whole body and in blood irradiation group. The chromosome aberration yield in whole body exposure group was higher than that in partial-body group and in the abdomen exposure group was higher than in that in the pelvic cavity irradiation; The chromosome aberration rate decreased with the time of post-exposure in partial and whole body by γ-ray irradiation

Protective effect of hypoxia in the ram testis during single and split-dose X-irradiation

International Nuclear Information System (INIS)

Vliet, J. van; Wensing, C.J.G.; Bootsma, A.L.; Peperzeel, H.A. van; Schipper, J.

1988-01-01

Spertogonial stem-cell survival in the ram was studied after single (6Gy) and split-dose X-irradiation both under normal and hypoxic conditions. Hypoxia was induced by inflation of an occluder implanted around the testicular artery. The occluders were inflated about 10 min before irradiation and deflated immediately after. Stem-cell survival was measured at 5 or 7 weeks after irradiation by determination of the Repopulation Index (RI) in histological testis sections. The RI-values after fractionated irradiation were only half those after single dose irradiation. Hypoxia had a protective effect on the stem-cell survival. After split-dose irradiation under hypoxic conditions two times more stem cells survived than under normal oxic conditions; the RI-values increased from 34% (oxic) to 68% (hypoxic). This effect of hypoxia was also found after single dose irradiation where the RI-values increased from 68% (oxic) to 84% (hypoxic). The development of the epithelium in repopulated tubules was also studied. Under hypoxia, a significantly higher fraction of tubules with complete epithelium was found after single (38 vs. 4%) as well as after split-dose irradiation (12 vs. 0%)

Search for the lowest irradiation dose from literatures on radiation-induced breast cancer

Energy Technology Data Exchange (ETDEWEB)

Yoshizawa, Y; Kusama, T [Tokyo Univ. (Japan). Faculty of Medicine

1975-12-01

A survey of past case reports concerning radiation-induced breast cancer was carried out in order to find the lowest irradiation dose. The search of literature published since 1951 revealed 10 cases of radiation-induced breast cancer. Only 5 cases had precise descriptions of the irradiation dose. The lowest irradiation dose was estimated at 1470 rads in the case of external X-ray irradiation for tuberous angioma. All of cases of radiation-induced breast cancer had received radiation for the treatment of nonmalignant tumors, such as pulmonary tuberculosis, mastitis, and tuberous angioma. There also were three statistical studies. The first concerned atomic bomb survivors, the second, pulmoanry tuberculous patients subjected to frequent fluoroscopies, and the third, patients of acute post partum mastitis. These statistical studies had revealed a significant increase in the incidence of breast cancer in the irradiated group, but there was little information about the lowest irradiation dose. It was noticed that radiation-induced breast cancer was more numerous in the upper inner quadrant of the breast. Most histopathological findings of radiation-induced breast cancer involved duct cell carcinoma. The latent period was about 15 years.

[Doses to organs at risk in conformational radiotherapy and stereotaxic irradiation: The heart].

Science.gov (United States)

Vandendorpe, B; Servagi Vernat, S; Ramiandrisoa, F; Bazire, L; Kirova, Y M

2017-10-01

Radiation therapy of breast cancer, Hodgkin lymphoma, lung cancer and others thoracic irradiations induce an ionizing radiation dose to the heart. Irradiation of the heart, associated with patient cardiovascular risk and cancer treatment-induced cardiotoxicity, increase cardiovascular mortality. The long survival after breast or Hodgkin lymphoma irradiation requires watching carefully late treatment toxicity. The over-risk of cardiac events is related to the dose received by the heart and the irradiated cardiac volume. The limitation of cardiac irradiation should be a priority in the planning of thoracic irradiations. Practices have to be modified, using modern techniques to approach of the primary objective of radiotherapy which is to optimize the dose to the target volume, sparing healthy tissues, in this case the heart. We have reviewed the literature on cardiac toxicity induced by conformational tridimensional radiation therapy, intensity-modulated radiation therapy or stereotactic body radiation therapy, in order to evaluate the possibilities to limit cardiotoxicity. Finally, we summarise the recommendations on dose constraints to the heart and coronary arteries. Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Dose distribution, using homogeneous material before the reload of the JS-6500 irradiator

International Nuclear Information System (INIS)

Carrasco A, H.

1991-10-01

The objective of this report is to determine the dose distribution inside the aluminum containers used for the industrial irradiation, as well as to locate the positions of maximum and minimum doses, before the reloading of the JS-6500 Irradiator. (Author)

Radiation dose in critical organs due to non-coplanar irradiation of the pituitary gland

International Nuclear Information System (INIS)

Schulte, R.W.M.; Rittmann, K.L.; Meinass, H.J.; Rennicke, P.

1996-01-01

In order to estimate the somatic and genetic risk associated with a non-coplanar linac-based radiation technique of the pituitary gland, systematic secondary-dose measurements in a phantom and sample measurements of the dose near critical organs of patients were performed. For measurements of the dose outside the primary radiation field an acrylic-PVC phantom was used which was irradiated with a single field (4x4 cm 2 ). Eight patients with pituitary tumors were treated isocentrically with a combination of sagittal and transverse rotational arcs. To measure the dose in critical organs, LiF thermoluminescence dosimeters (TLD) in chip form were placed onto 1 eyelid, the skin over the thyroid, and the patient's clothes covering the region of breasts and ovaries of female patients and the testicles of male patients. Measurements were performed for all patients during 1 sagittal irradiation and for the majority of patients during 1 transverse irradiation. The phantom measurements demonstrated that the secondary dose measured on the patients surface can be considered as a good approximation for the dose in adjacent organs. The median dose in critical organs for sagittal irradiation was in the range of 25.8 mGy (eyes) to 1.9 mGy (testicles), and for transverse irradiation in the range of 23.3 mGy (eyes) to 1.3 mGy (testicles). The ratio of median organ doses for sagittal and transverse irradiation was 2.1 for the thyroid gland, 1.1 for the eyes, and 1.5 for the other organs. The dose in critical organs due to non-coplanar irradiation of the pituitary gland is only a small fraction of the dose delivered to the reference point of the planning target volume. The risk of a radiation-induced tumor and a genetic consequence associated with these small doses is generally less than 1% and 0.1%, respectively. (orig./MG) [de

Repair of sublethal damage in mammalian cells irradiated at ultrahigh dose rates

International Nuclear Information System (INIS)

Gerweck, L.E.; Epp, E.R.; Michaels, H.B.; Ling, C.C.; Peterson, E.C.

1979-01-01

The lethal response of asynchronous Chinese hamster ovary (CHO) cells exposed to single and split doses of radiation at conventional or ultrahigh dose rates has been examined to determine whether repair of sublethal damage occurs in cells irradiated at ultrahigh dose rates. The high-intensity irradiations were performed with electrons delivered in single 3-nsec pulses from a 600-kV field emission source under medium-removed, thin-layer conditions. Conventional dose-rate experiments were done under identical thin-layer conditions with 50-kVp x rays, or under full-medium conditions with 280-kVp x rays. Oxygenated cells were irradiated and maintained at 22 to 24 0 C between exposures. Survival did not increase as the time between two doses of pulsed electrons increased from 0 to 4 min, indicating no evidence of fast repair. However, increased survival was observed when 30 to 90 min was allowed to elapse between the split doses. The half-time for maximum repair was approx. = 30 min irrespective of the exposure conditions and radiation modality used. Observed repair ratios increased from approx. = 2 to 4 as the single-dose surviving fraction decreased from 10 -2 to 5 x 10 -4 . Over this survival range the repair ratios, measured at the same value of surviving fraction, were independent of dose rate. The observed repair ratios imply that the shoulder regions of the nonfractionated x-ray and pulsed-electron survival curves were not completely restored between the split doses. However, the fraction of the shoulder restored between split doses of radiation was dose-rate-independent. It is concluded that sublethal damage can be repaired in oxygenated CHO cells irradiated at dose rates of the order of 10 11 rad/sec

Orientation of streptococcus agalactiae irradiation dose for subclinical mastitis vaccine in dairy cows

International Nuclear Information System (INIS)

Tuasikal, B.J.; Estuningsih, S.; Pasaribu, F.H.; Wibawan, I.W.T.

2012-01-01

An experiment to determine the effect of gamma-ray irradiation in debilitating Streptococcus agalactiae as a cause of subclinical mastitis (inflammation of the udder) in cows has been conducted. S. agalactiae bacteria was isolated from subclinical mastitis found in dairy cows in the field was then observed for its cell growth. The bacteria which have reached mid-log phase of growth, were divided into 5 treatment groups, of which each was irradiated at dose level of 0; 25; 50; 75; and 100Gy. Irradiated bacteria subsequently were grown on Brain Heart Infusion agar (BHI), and each of its colonies was counted for LD50 determination. The obtained curves from irradiated treatment bacterial shown viability percentage by the linier equation of Y = 95.414 e -0,0371X ; R 2 = 0.9979, while Y = % viability and X = dose of irradiation. The calculation done in this experiment shows that irradiation dose of 17.4 Gy weaken the bacteria pathogenicity of S. agalactiae to the level of LD 50 . (author)

Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators

International Nuclear Information System (INIS)

Belley, Matthew D.; Wang, Chu; Nguyen, Giao; Gunasingha, Rathnayaka; Chao, Nelson J.; Chen, Benny J.; Dewhirst, Mark W.; Yoshizumi, Terry T.

2014-01-01

Purpose: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. Methods: Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. Results: Average doses in soft-tissue organs were found to vary by as much as 23%–32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. Conclusions: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs

Protection of lethally irradiated mice with allogeneic fetal liver cells: influence of irradiation dose on immunologic reconstitution

International Nuclear Information System (INIS)

Tulunay, O.; Good, R.A.; Yunis, E.J.

1975-01-01

After lethal irradiation long-lived, immunologically vigorous C3Hf mice were produced by treatment with syngeneic fetal liver cells or syngeneic newborn or adult spleen cells. Treatment of lethally irradiated mice with syngeneic or allogeneic newborn thymus cells or allogeneic newborn or adult spleen cells regularly led to fatal secondary disease or graft-versus-host reactions. Treatment of the lethally irradiated mice with fetal liver cells regularly yielded long-lived, immunologically vigorous chimeras. The introduction of the fetal liver cells into the irradiated mice appeared to be followed by development of immunological tolerance of the donor cells. The findings suggest that T-cells at an early stage of differentiation are more susceptible to tolerance induction than are T-lymphocytes at later stages of differentiation. These investigations turned up a perplexing paradox which suggests that high doses of irradiation may injure the thymic stroma, rendering it less capable of supporting certain T-cell populations in the peripheral lymphoid tissue. Alternatively, the higher and not the lower dose of irradiation may have eliminated a host cell not readily derived from fetal liver precursors which represents an important helper cell in certain cell-mediated immune functions, e.g., graft-versus-host reactions, but which is not important in others, e.g., allograft rejections. The higher dose of lethal irradiation did not permit development or maintenance of a population of spleen cells that could initiate graft-versus-host reactions but did permit the development of a population of donor cells capable of achieving vigorous allograft rejection

Effect of pelvic irradiation on the absorption of bile acids

International Nuclear Information System (INIS)

Stryker, J.A.; Demers, L.M.

1979-01-01

The pathophysiology of radiation-induced diarrhea was evaluated in 17 patients undergoing pelvic irradiation for gynecological malignancies. The glycine conjugates of cholic acid (GC) and chenodeoxycholic acid (GCDC) were measured in serum by radioimmunoassay. Fasting and 2 hour post prandial (pp) determinations were performed prior to and in the fifth week of radiotherapy. The pre-treatment fasting and 2 hour pp GC levels were 0.20 +- 0.29 (mean +- SD) and 0.48 +- 0.47 μM. In the fifth week the fasting and 2 hour pp GC levels were 0.16 +- 0.23 and 0.25 +- 0.27 μM. The first week fasting and 2 hour pp GCDC levels were 0.32 +- 0.47 and 0.80 +- 0.83 μM: in the fifth week they were 0.10 +- 0.06 and 0.33 +- 0.27 μM. The differences between the first and the fifth week post prandial increases in serum GC and GCDC levels were significant (P<0.02). The reduced post prandial increases in serum GC and GCDC in the fifth week of radiotherapy occurred at a time when the patients' daily stool frequencies were significantly increased (P<0.01). The data suggest that a cholerrheic enteropathy is the major determinant in the pathophysiology of radiation-induced diarrhea

Alternatives to dose, quality factor and dose equivalent for low level irradiation

International Nuclear Information System (INIS)

Sondhaus, C.A.; Bond, V.P.; Feinendegen, L.E.

1988-01-01

Randomly occurring energy deposition events produced by low levels of ionizing radiation interacting with tissue deliver variable amounts of energy to the sensitive target volumes within a small fraction of the cell population. A model is described in which an experimentally derived function relating event size to cell response probability operates mathematically on the microdosimetric event size distribution characterizing a given irradiation and thus determines the total fractional number of responding cells; this fraction measures the effectiveness of the given radiation. Normalizing to equal numbers of events produced by different radiations and applying this cell response or hit size effectiveness function (HSEF) should define radiation quality, or relative effectiveness, on a more nearly absolute basis than do the absorbed dose and dose evaluation, which are confounded when applied to low level irradiations. Examples using both calculation and experimental data are presented. 15 refs., 18 figs

The effect of low dose gamma irradiation on maize production (1985-1988)

International Nuclear Information System (INIS)

Al-Oudat, M.; Khalifa, K.

1990-06-01

Presowing seed irradiation has been reported as a useful application of radiation in agriculture to stimulate growth and increase the yield of certain field crops. To the best of our knowledge the feasibility of this treatment has not yet been tested on maize in Syria. Our experiments were carried out in controlled, in field conditions, and in a large scale application. Samples of air dried seeds of maize (Var. Gota-82 and LG-11) of previous season were irradiated by gamma-rays from a 137 Cs sourse using doses of 5, 7.5, 10, 15, 20, 30, 40 and 50 Gy. at dose rate of 9.8 - 9.2 Gy/min. Then were planted after 2 days from irradiation with unirradiated control, in complete randomized block design and replicated 4 times for four seasons (1985-1988). The date revealed that gamma irradiation, at interval doses of 5 - 10 Gy led to, first: Acceleration of seed germination, faster development, intensive development of root system, increase plant hieght (12 - 19%) and significant increase in ear size and number, and second: Increase both green mass (15 - 35%) and seed yield (10 - 31%), and percentage of seed protein (2 - 17%). Large scale applications were performed in 1987 and 1988 using a transportable irradiation unit POC-1 137 Cs and dose of 7.5 Gy. A significant yield increase was obtained from all fields. The average percentage increment varied from 13 - 30% which is approximately 382-765 Kg/h. Therefore, presowing seed irradiation with low doses gamma irradiation ranging from 5 to 10 Gy, was found to be feasible for application in qualitative and quantitative improvement of maize yield. (author). 38 refs., 12 figs., 44 tabs

Clinical trial evaluating cholestyramine to prevent diarrhea in patients maintained on low-fat diets during pelvic radiation therapy

International Nuclear Information System (INIS)

Chary, S.; Thomson, D.H.

1984-01-01

A prospective randomized trial to determine the value of a low fat diet with or without cholestyramine in the treatment of acute intestinal complications of pelvic irradiation is presented. A total of 35 patients receiving pelvic irradiation were entered in the study and all patients had received a 40 gm fat diet. The group was then randomized to receive either placebo (17 patients) or cholestyramine (18 patients). Diarrhea occurred in six out of 16 evaluable patients in the control group and only one of the 17 evaluable patients in the cholestyramine group. The frequency of diarrhea and the diarrhea scale remained high in the placebo group in the entire observation period. Statistical analysis had revealed better diarrhea control in the cholestyramine group. In this report mechanism by which diarrhea occurs following pelvic irradiation is discussed. The adverse effects associated with the use of cholestyramine have been presented. It was concluded that cholestyramine is effective in preventing acute diarrhea induced by pelvic irradiation in patients receiving a low fat diet but is associated with side effects

Factors influencing bowel sparing in intensity modulated whole pelvic radiotherapy for gynaecological malignancies

International Nuclear Information System (INIS)

Georg, Petra; Georg, Dietmar; Hillbrand, Martin; Kirisits, Christian; Poetter, Richard

2006-01-01

Background and purpose: To evaluate the influence of uterus and bladder size on large and small bowel sparing with intensity modulated whole pelvic radiotherapy (IM-WPRT) in gynecologic patients. Patients and methods: Twenty patients were selected; 10 women with cervical cancer treated with definitive radiotherapy (group 'DEF') and 10 endometrial cancer patients treated postoperatively (group 'POST'). Bladder, rectal wall, small (SB) and large bowel (LB) were delineated as organs at risk. A conformal four field technique and a seven field IMRT plan (prescription dose 50.4 Gy) were compared in terms of DVH and various target parameters. Results: At doses between 40 and 50.4 Gy statistically significant improvements (P<0.05) were observed for IM-WPRT for irradiated volume of rectal wall and bladder. In both patient groups, with IMRT the average irradiated volume of SB was reduced by a factor of 6 at 50.4 Gy. This ratio was 2 for LB. In the DEF group the effect of SB-sparing with IMRT correlated with bladder size (correlation coefficient 0.70) while it did not correlate in the postoperative group. The effect of LB-sparing decreased with increasing bladder size in both groups but the impact of IMRT was larger for postoperative patients. Conclusions: IMRT significantly reduced the absolute volume of rectal wall, bladder and bowel irradiated at the prescribed dose level in gynaecologic patients. Main differences between POST and DEF patients receiving IM-WPRT were absolute volumes of LB irradiated to doses between 35 and 50 Gy, suggesting an impact of intact uterus on LB volume in the pelvis. POST patients seem to benefit most from elective nodal IMRT. Bladder filling is an important co-factor influencing the benefit of IMRT with respect to OAR sparing

Genetic effects of low-dose irradiation in Drosophila Melanogaster

International Nuclear Information System (INIS)

Zajnulin, V.G.; Shaposhnikov, M.V.; Yuraneva, I.N.

2000-01-01

Influence of chronic γ-irradiation at the dose rate of 0.17 cGy/h on the rate of genetic variability in the laboratory strains of Drosophila Melanogaster with genotypic distinguishes by families of mobile genetic elements and of systems of hybrid disgenesis and also violations in reparation processes control mechanisms. It was shown that the rates of induction of recessive lethal mutations depended on genotype of investigated strains. In the different strains an increase as well as a decrease of the mutation rate were observed. Also in was established that irradiation leads to the increase in frequencies of the gonads sterility and mutability of the sn w and h(w + ) in the P-M and H-E dysgenic crosses. Obtained results suggest that mobile genetic elements play an important role in the forming of genetic effects in response to low dose irradiation [ru

Neutron and X-ray diffraction analysis of the effect of irradiation dose and temperature on microstructure of irradiated HT-9 steel

International Nuclear Information System (INIS)

Mosbrucker, P.L.; Brown, D.W.; Anderoglu, O.; Balogh, L.; Maloy, S.A.; Sisneros, T.A.; Almer, J.; Tulk, E.F.; Morgenroth, W.; Dippel, A.C.

2013-01-01

Material harvested from several positions within a nuclear fuel duct (the ACO-3 duct) used in a 6-year irradiation of a fuel assembly in the Fast Flux Test Reactor Facility (FFTF) was examined using neutron and high-energy X-ray diffraction. Samples with a wide range of irradiation dose and irradiation temperature history, reaching doses of up to 147 dpa and temperatures of up to 777 K, were examined. The response of various microstructural characteristics such as the weight fraction of M 23 C 6 carbides, the dislocation density and character, and the crystallographic texture were determined using whole profile analysis of the diffraction data and related to the macroscopic mechanical behavior. For instance, the dislocation density was observed to be intimately linked with observed flow strength of the irradiated materials, following the Taylor law. In general, at the high doses studied in this work, the irradiation temperature is the predominant controlling factor of the dislocation density and, thus, the flow strength of the irradiated material. The results, representing some of the first diffraction work done on samples exposed to such a high received dose, demonstrate how non-destructive and stand-off diffraction techniques can be used to characterize irradiation induced microstructure and at least estimate mechanical properties in irradiated materials without exposing workers to radiation hazards

Model of the dose rate for a semi industrial irradiation plant. Pt. 2

International Nuclear Information System (INIS)

Mangusi, Josefina

2004-01-01

The second stage of the model for the absorbed dose rate in air for the enclosure of a half-industrialist irradiation plant operating with cobalt-60 sources holden in plan geometry is presented. The sensibility of the model with the treatment of the support structure of the irradiator is analyzed and verified with experimental measurements with good accord. The model of the absorbed dose rate in air in the case of an interposed material between the radioactive sources and the point of interest includes in its calculation a set of secondary radioactive sources created by the Compton scattering of the primary radiation. The accord of the calculated absorbed dose rate and the experimental measured ones is good. The transit dose due to the irradiator moving until its dwell position is also modeled. The isodose curves for a set of irradiator parallel planes are also generated. (author) [es

Caffeine protects mice against whole-body lethal dose of {gamma}-irradiation

Energy Technology Data Exchange (ETDEWEB)

George, K.C.; Hebbar, S.A.; Kale, S.P.; Kesavan, P.C. [Biosciences Group, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

1999-06-01

Administration of caffeine (1,3,7-trimethylxanthine), a major component of coffee, to Swiss mice at doses of 80 or 100 mg/kg body weight 60 min prior to whole-body lethal dose of {gamma}-irradiation (7.5 Gy) resulted in the survival of 70 and 63% of animals, respectively, at the above doses in contrast to absolutely no survivors (LD-100/25 days) in the group exposed to radiation alone. Pre-treatment with a lower concentration of caffeine (50 mg/kg) did not confer any radioprotection. The protection exerted by caffeine (80 mg/kg), however, was reduced from 70 to 50% if administered 30 min prior to irradiation. The trend statistics reveal that a dose of 80 mg/kg administered 60 min before whole-body exposure to 7.5 Gy is optimal for maximal radioprotection. However, caffeine (80 mg/kg) administered within 3 min after irradiation offered no protection. While there is documentation in the literature that caffeine is an antioxidant and radioprotector against the toxic pathway of radiation damage in a wide range of cells and organisms, this is the first report demonstrating unequivocally its potent radioprotective action in terms of survival of lethally whole-body irradiated mice. (author)

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

Directory of Open Access Journals (Sweden)

Kropf Siegfried

2011-09-01

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

Dose rate modelled for the outdoors of a gamma irradiation

International Nuclear Information System (INIS)

Mangussi, J

2012-01-01

A model for the absorbed dose rate calculation on the surroundings of a gamma irradiation plant is developed. In such plants, a part of the radiation emitted upwards reach's the outdoors. The Compton scatterings on the wall of the exhausting pipes through de plant roof and on the outdoors air are modelled. The absorbed dose rate generated by the scattered radiation as far as 200 m is calculated. The results of the models, to be used for the irradiation plant design and for the environmental studies, are showed on graphics (author)

Aging irradiation of polymers. Dose-rate and test sequence influence

International Nuclear Information System (INIS)

Alba, C.; Carlin, F.; Chenion, J.; Lemaire, F.; Le Meur, M.; Petitjean, M.

1984-05-01

This work brings up results of the irradiation dose-rate influence on mechanical and electrical properties of technical polymer materials evolution. Polymer samples were subjected to 3.3.10 -2 Gy.s -1 and 2.8.10 -1 Gy.s -1 dose-rate. Heat and radiation simultaneous action is usualy simulated sequentialy. The hardest simulation on the polymer is the sequence of irradiation followed by thermal aging not the reverse. This study was carried out on eight polymer materials among those used in the electrical appliances for P.W.R. nuclear power plants [fr

Increase of onion yield through low dose of gamma irradiation of its seeds

International Nuclear Information System (INIS)

Wiendl, F.M.; Wiendl, F.W.; Wiendl, J.A.; Vedovatto, A.; Arthur, V.

1995-01-01

The increase of onions' yield could be achieved by the common farmer through the use of nuclear techniques. This report describes the results obtained with the irradiation of onion seeds, with low doses of gamma radiations (Cobalt-60), at doses of 0 (control), 150, 400 and 700 Gy. Beyond the proper onion's variety als use of low dose rates of 13.1, 39.2 and 52.3 Gy per hour were of the great importance during irradiation. The results showed to be promising both in laboratory studies and in the field, resulting in an increase of onions production: A greater number of seedlings, bulbs and a higher yield in weight per hectar were planted. In the field the most promising dose and dose rate to the variety ''Super-X'' were respectively 150 Gy and 13.1 Gy per hour, yielding an 24.9 percent heavier weight of onions than the control. The other tested variety was ''Granex-33'', which did not respond so favorable to irradiation. However, also with this variety we harvested a 2.1 percent heavier weight than its control, if the onion seeds were irradiated with the dose of 700 Gy at a dose rate of 13.1 Gy per hour. (Author)

The effect of irradiation dose and age of bird on the ESR signal in irradiated chicken drumsticks

International Nuclear Information System (INIS)

Gray, R.; Stevenson, M.H.; Kilpatrick, D.J.

1990-01-01

Groups of 20 broiler chickens of the same genetic strain and reared under identical conditions were slaughtered at either 4, 5, 6, 7 or 8 weeks of age. Pairs of drumsticks were removed from each bird and groups were either not irradiated or irradiated at 2.5, 5.0, 7.5 or 10.0 kGy using a cobalt 60 source. Bone samples were excised, fragmented, freeze dried and ground prior to the determination of free radical concentration using electron spin resonance (ESR) spectroscopy. Increasing irradiation dose gave a highly significant increase in free radical concentration whilst for each irradiation dose, bones from younger birds gave significantly lower concentrations compared to those for older birds. Crystallinity coefficient increased linearly with age of bird and this may account in part for the increased signal observed as the birds aged. (author)

Effect of low doses gamma irradiation on seed, bulblets and bulbs of onion

International Nuclear Information System (INIS)

Al-Oudat, Mohammad

1991-10-01

Presowing seed irradiation has been reported as a useful application of radiation in agriculture to stimulate growth and increase the yield of certain crops. To the best of our knowledge the feasibility of this treatment has not yet been tested on onion in Syria. The effect of low doses gamma irradiation on onion seeds, bulblets and bulbs of two local varieties, red and white, was studied during three consecutive seasons (1986 - 1988). Air dried seeds were irradiated by gamma rays from 137 Cs source. Five, 10, 15, 20 and 30 GY, were applied at dose rate of 9.8 Gy/min. The irradiation of onion bulblets and bulbs were carried out with gamma-rays from 60 Co source at a dose rate of 0.5 Gy/min. using 1, 2, 3, 4 and 5 Gy. Within 7 - 10 days after irradiation, both controlled and irradiated seeds, bulblets and bulbs were sown in the field in complete randomized block design with 4 replicates. Irradiation of seeds with doses of 5, 10 and 15 Gy led to highly significant increases in bulblets yield in the three seasons. The increases ranged from 14.5 to 22.1 for red variety and from 16.2 to 22.3 for white variety. The irradiation of bulblets with 1 and 2 Gy increase significantly the yield of bulbs by 21.6 - 26.0% for red variety and 21.6 - 24.4% for white variety. A considerable increase in seed yield was obtained after irradiation of bulbs with 1 and 2 Gy doses. The average increment was about 21.0% for both varieties. Large scale application were performed in 1989 and 1990 using doses of 10 Gy for seeds and 1 Gy for bulblets and bulbs. A considerable increase in the yield was obtained. The average percentage increment was 16.9% and 23.3% for seeds, 18.6 and 20.9% for bulblets, 24.8 and 27.3% for bulbs, for red and white varieties respectively. Therefore, presowing irradiation of seeds, bulblets and bulbs of onion with low doses of gamma-rays (5 - 15 Gy for seeds and 1 - 2 Gy for bulblets and bulbs) can be of practical application resulting in improvement of yield of

Alterations in water and electrolyte absorption in the rat colon following neutron irradiation: influence of neutron component and irradiation dose.

Science.gov (United States)

Dublineau, I; Ksas, B; Joubert, C; Aigueperse, J; Gourmelon, P; Griffiths, N M

2002-12-01

To study the absorptive function of rat colon following whole-body exposure to neutron irradiation, either to the same total dose with varying proportion of neutrons or to the same neutron proportion with an increasing irradiation dose. Different proportions of neutron irradiation were produced from the reactor SILENE using a fissile solution of uranium nitrate (8, 47 and 87% neutron). Water and electrolyte fluxes were measured in the rat in vivo under anaesthesia by insertion into the descending colon of an agarose gel cylinder simulating the faeces. Functional studies were completed by histological analyses. In the first set of experiments, rats received 3.8 Gy with various neutron percentages and were studied from 1 to 14 days after exposure. In the second set of experiments, rats were exposed to increasing doses of irradiation (1-4Gy) with a high neutron percentage (87%n) and were studied at 4 days after exposure. The absorptive capacity of rat colon was diminished by irradiation at 3-5 days, with a nadir at 4 days. The results demonstrate that an increase in the neutron proportion is associated with an amplification of the effects. Furthermore, a delay in the re-establishment of normal absorption was observed with the high neutron proportion (87%n). A dose-dependent reduction of water absorption by rat colon was also observed following neutron irradiation (87%n), with a 50% reduction at 3 Gy. Comparison of this dose-effect curve with the curve obtained following gamma (60)Co-irradiation indicates an RBE of 2.2 for absorptive colonic function in rat calculated at 4 days after exposure.

Nanoindentation and in situ microcompression in different dose regimes of proton beam irradiated 304 SS

Energy Technology Data Exchange (ETDEWEB)

Reichardt, A. [Department of Nuclear Engineering, University of California, Berkeley, CA (United States); Lupinacci, A. [National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Frazer, D.; Bailey, N.; Vo, H.; Howard, C. [Department of Nuclear Engineering, University of California, Berkeley, CA (United States); Jiao, Z. [Department of Nuclear Engineering, University of Michigan, Ann Arbor, MI (United States); Minor, A.M. [National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Chou, P. [Electric Power Research Institute, Palo Alto, CA (United States); Hosemann, P., E-mail: peterh@berkeley.edu [Department of Nuclear Engineering, University of California, Berkeley, CA (United States)

2017-04-01

Recent developments in micromechanical testing have allowed for the efficient evaluation of radiation effects in micron-scale volumes of ion-irradiated materials. In this study, both nanoindentation and in situ SEM microcompression testing are carried out on 10 dpa proton beam irradiated 304 stainless steel to assess radiation hardening and radiation-induced deformation mechanisms in the material. Using a focused ion beam (FIB), arrays of 2 μm × 2 μm cross-section microcompression pillars are fabricated in multiple dose regimes within the same grain, providing dose-dependent behavior in a single crystal orientation. Analysis of the microcompression load-displacement data and real-time SEM imaging during testing indicates significant hardening, as well as increased localization of deformation in the irradiated material. Although nanoindentation results suggest that irradiation hardening saturates at low doses, microcompression results indicate that the pillar yield stress continues to rise with dose above 10 dpa in the tested orientation. - Highlights: •Mechanical properties are probed in small volumes of proton irradiated 304SS. •Nanoindentation indicates saturation of irradiation hardening at doses of 5–10 dpa. •Microcompression of irradiated specimens suggest localized deformation.

Design of compensators for patients with hip prostheses undergoing pelvic irradiation

International Nuclear Information System (INIS)

Alecu, R.; Feldmeier, J.; He, T.; Alecu, M.; Court, W.; Orton, C.G.

1995-01-01

The perturbations in the dose distribution caused by a hip prosthesis when treating pelvic cancers have been evaluated and found to be significant by several investigators. Treatment techniques not including the prosthesis are often not the best choice. The goal of this study is to investigate the feasibility and usefulness of design of compensators in routine clinical practice for any kind of hip prosthesis. The calculation procedures and the algorithms developed by the authors for generating the compensators are described for two systems: one based on a locally developed 3-D computerized treatment planning system and an other one practicable in any institution which does not have access to a 3D treatment planning system or CT. The methodology to create the compensators for a patient is explained. To evaluate the constructed compensators in phantom and in vivo measurements were performed. The results are presented along with a comparison between the two methods

Can prenatal low-dose irradiation affect behavior of adult rats?

International Nuclear Information System (INIS)

Smajda, B.; Tomasova, L.; Kokocova, N.

2011-01-01

The aim of our study was to determine whether exposure of very low dose gamma-rays during the critical phase of brain development affects some selected behavioral parameters in adult rats. Pregnant female Wistar rats were irradiated with 1 Gy gamma-rays from a cobalt source at 17 th day of pregnancy. The progeniture of irradiated as well as non-irradiated females have undergone behavioral tests at the age of 3 months. Irradiated animals exhibited lower locomotor and exploratory activity in the open field test. (authors)

Ovarian irradiation in recurrent endometriosis; Irradiation ovarienne pour endometriose refractaire inoperable

Energy Technology Data Exchange (ETDEWEB)

Kochbati, L.; Chaari, N.; Besbes, M.; Maalej, M. [Institut Salah-Azaiz, Service de Radiotherapie Carcinologique Tunis (Tunisia); Neji, K.; Ben Amara, F. [Centre de Maternite et de Neonatologie de Tunis, Service B (Tunisia); Ben Romdhane, N.K. [Hopital La-Rabta, Service d' Hematologie, Tunis (Tunisia)

2005-09-15

We describe a case of a young woman with a history of an aplastic anaemia in which pelvic radiotherapy was used successfully in the management of a recurrent and inoperable endometriosis. The use of therapeutic pelvic or ovarian irradiation in endometriosis may be considered, when surgical and medical treatments have been exhausted and have failed. (authors)

Effects of irradiation at different dose rates on the onset of type I diabetes in model mice

International Nuclear Information System (INIS)

Nomura, Takashi; Sakai, Kazuo

2003-01-01

We previously demonstrated that low-dose irradiation (0.5 Gy) increased the level of antioxidants and decreased the level of lipid peroxide in normal mice. We also found that 0.5 Gy-irradiation of NOD mice suppressed the onset of type I diabetes. These results were obtained by the irradiation at high dose rate. The aim of the present study is to examine the effects at the low dose rate. The mice were acutely irradiated with 0.5 Gy of X-rays (300 kVp) at 94.2 Gy/hr at 10, 11, 12, 13 or 14 weeks of age, or chronically irradiated with 0.5 Gy of 137 Cs γ-rays at 0.95 mGy/hr starting at 10,11,12,13 or 14 weeks of age. When irradiated at 12th week with the high dose rate X-rays, the onset of diabetes suppressed, and the increase in the specific activity of superoxide dismutase (SOD) in pancreas was observed. On the other hand, the low dose rate γ-rays delivered from 12th week of age to 14th was less effective in the suppression of the incidence of diabetes than the high dose rate X-rays at the 12-14 weeks of age. Furthermore, the significant increase in pancreatic SOD activity was not observed after the low dose irradiation. Splenic macrophage activities of superoxide generation were not affected by the high dose rate irradiation nor the low dose rate irradiation. (author)

Effective dose as an irritating influence during fractionated γ-irradiation

International Nuclear Information System (INIS)

Karpov, V.N.; Ushakov, I.B.; Davydov, B.I.

1990-01-01

The study of early neurological disturbances (END) in rats after fractionated γ-irradiation with doses of 37.5-225 Gy at dose rate of 30.11 Gy/min has demonstrated that the initial response of animals to pulse ionizing radiation is a function of the electric charge induced by ionizing radiation. A change in the probability of occurrence of each of the END symptoms, with the increased intervals between exposures, is merely an indirect indication of the eliminating mechanisms and is intricately connected with the irritating charge value. The proposed empiric relationships permit to correlate the probability of END symptom occurrence with the continuous quantitative parameter of fractionated irradiation, that is, with an effective dose as an analogue of the irritating effect

Experimental research on fresh mussel meat irradiated by high-dose electron beam

International Nuclear Information System (INIS)

Xiao Lin; Lu Ruifeng; Hu Huachao; Wang Chaoqi; Liu Yanna

2011-01-01

The sterilization storage of fresh mussel irradiated high-dose electron beam was studied. From the subjective assessment by the weighted average of the test and other determined parameters, it can be concluded that the flavor of fresh mussel meat sealed canned food irradiated by high-dose electron beam has not been significant affected, and various micro-organisms can be killed effectively, which means that the irradiated fresh mussel meat can be preserved for long-term at room temperature. Therefore the method might resolve the problems induced by traditional frozen preservation methods. (authors)

Relationship of dose rate and total dose to responses of continuously irradiated beagles

International Nuclear Information System (INIS)

Fritz, T.E.; Norris, W.P.; Tolle, D.V.; Seed, T.M.; Poole, C.M.; Lombard, L.S.; Doyle, D.E.

1978-01-01

Young-adult beagles were exposed continuously (22 hours/day) to 60 Co gamma rays in a specially constructed facility. The exposure rates were 5, 19, 17 or 35 R/day, and the exposures were terminated at 600, 1400, 2000 or 4000 R. A total of 354 dogs were irradiated; 221 are still alive as long-term survivors, some after more than 2000 days. The data on survival of these dogs, coupled with data from similar preliminary experiments, allow an estimate of the LD 50 for gamma-ray exposures given at a number of exposure rates. They also allow comparison of the relativeimportance of dose rate and total dose, and the interaction of these two variables, in the early and late effects after protracted irradiation. The LD 50 for the beagle increases from 344 R (258 rads) delivered at 15 R/minute to approximately 4000 R (approximately 3000 rads) at 10 R/day. Over this entire range, the LD 50 is dependent upon haematopoietic damage. At 5 R/day and less, no definitive LD 50 can be determined; there is nearly normal continued haematopoietic function, survival is prolonged, and the dogs manifest varied individual responses in the organ systems. Although the experiment is not complete, interim data allow serveral important conclusions. Terminated exposures, while not as effective as irradiation continued until death, can produce myelogenous leukaemia at the same exposure rate, 10 R/day. More importantly, at the same total accumulated dose, lower exposure rates appear more damaging than higher rates on the basis of the rate and degree of haematological recovery that occurs after termination of irradiation. Thus, the rate of haematologic depression, the nadir of the depression and the rate of recovery are dependent upon exposure rate; the latter is inversely related and the first two are directly related to exposure rate. ( author)

Shelf Life of Tilapia Fillets Treated with low dose Gamma Irradiation

International Nuclear Information System (INIS)

Mohamed, W.S.; El-Mossalami, I.I.

2009-01-01

The bacterial load (total bacterial count), Psychrophilic count, chemical and sensory examinations in Tilapia fish fillets were determined to evaluate its sanitary status and to increase its storage period during storage at -18 degree C for one year. The experiment was carried out at the time of receiving the samples and after gamma radiation treatment with dose levels of 1, 2 and 3 kGy. The initial total bacterial count was 5.4x10 0 cfu/gm and the psychrophilic count was 4x10 5 cfu/gm; it was slightly increased during freezing storage. The chemical parameters were more indicative in evaluating the shelf life of frozen fish; as they exceeded the permissible limits, so that the frozen non-irradiated samples were rejected after 6 months. The exposure to gamma irradiation at a dose of 1 kGy extended the storage time of the samples to 9 months while irradiation with 3 kGy extended the storage time of the samples to 12 months without changing its quality attributes. The quality during storage at -18 degree C of non irradiated and irradiated fish fillets was investigated every 3 months for one year by measuring the bacterial counts, chemical parameters and sensorial evaluation of the samples to study the effect of irradiation on increasing the storage time of fish fillets. So, it is recommended that fish fillets should be properly cleaned, packaged and exposed to gamma irradiation at a dose of 3 kGy to extend its freezing storage period

High doses dosimetry in irradiation process in Argentine

International Nuclear Information System (INIS)

Dorda de Cancio, E.M.

1997-01-01

These report describes the lung dose dosimetry procedures of the Semi-Industrial Irradiation Plant in Ezeisa Atomic (500,00 Ci of Co 60) and Industrial Picorrad Plant (400,00 Ci of Co 60) using the nitrate dosimeter

Improvement of dose distribution of esophageal irradiation using the field-within-a-field technique

International Nuclear Information System (INIS)

Iwai, Tsugunori; Okabe, Keigo; Yamato, Hidetada; Murakami, Jyunji; Nakazawa, Yasuo; Kato, Mitsuyoshi

2002-01-01

The wide radiation field for mediastinal dose distribution should be inhomogeneous with the usual simple opposed beam irradiation. The purpose of this study was to improve the dose distribution of the mediastinum using a conventional planning system with a dose-volume histogram (DVH) and the field-in-field technique. Three-dimensional (3D) dose distribution is obtained in bilateral opposed-field irradiation. An overdose area obtained from the 3D dose distribution is defined and reprojected into the irradiation field. A new reduced field is created by removing the reprojected overdose area. A 3D dose distribution is again obtained and compared with the results from first one. Procedures were repeated until each of the target volumes was within ±5% of the prescribed dose and the irradiation volume within 107% or less of the prescribed dose. From the DVH analysis, our field-within-a-field technique resulted in a more uniform dose distribution within the conventional planning. The field-within-a-field technique involves many parameters, and an inverse planning algorithm is suitable for computation. However, with our method, the forward planning system is adequate for planning, at least in a relatively straightforward planning system such as bilateral opposed fields therapy. (author)

Gonad shielding in paediatric pelvic radiography : Disadvantages prevail over benefit

NARCIS (Netherlands)

Frantzen, M.J.; Robben, S.; Postma, A.A.; Zoetelief, J.; Wildberger, J.E.; Kemerink, G.J.

2012-01-01

Objective To re-evaluate gonad shielding in paediatric pelvic radiography in terms of attainable radiation risk reduction and associated loss of diagnostic information. Methods A study on patient dose and the quality of gonad shielding was performed retrospectively using 500 pelvic radiographs of

X-raying with low dose irradiation

International Nuclear Information System (INIS)

Malevich, E.E.; Kisel, E.M.; Shpita, I.D.; Lazovsky, A.S.

2001-01-01

With the purpose of the improvement of diagnostics quality and reduction of beam load on a patient in modern x-ray devices pulse x-raying is applied. It is based on the using of radiation pulses with various frequencies of intervals between them instead of continuous radiation. At pulse x-raying with the net control the principle of filling of an interval is used, when the information about the image, received with the last pulse, get into memory and is displayed before occurrence of other pulse. It creates impression of the continuous image even at low frequency of pulses. Due to the unique concept of the simultaneous (double) control, all of 3 parameters, which define the quality of the image (pressure(voltage), force of a current and length of a pulse), are adjusted automatically at each pulse, thus optimum adaptation to varied thickness of object during dynamic researches occurs. At x-raying pulse the presence of a free interval from x-ray radiation between two pulses results in the decrease of a radiation dose. Pulsing occurs some times per one second with equal intervals between pulses. Thus, the degree of decrease irradiation dose depends on duration of a pause between pulses. On the screen the image of last pulse before occurrence of the following is kept and repeats. The principle of x-raying pulse was realized in system Grid Controlled Fluoroscopy by the firm 'Philips Medi zin Systeme'. In the x-ray tube of this system inclusion and de energizing of radiation occurs directly on a source. Electron cloud is broken off by the special grid, which is located between the cathode and the anode and operates as a barrier. Thus the tube continues to be energized. In usual devices for pulses formation is used generator pulsation system, which at increase and attenuation of a x-ray pulse results in occurrence of the increasing and fading radiation which are not participating in the formation of the image, but creating beam load on the patient and the personnel. Thus

Problems following hippocampal irradiation in interventional radiologists - doses and potential effect:a Monte Carlo simulation

International Nuclear Information System (INIS)

Cumak, V.; Morgun, A.; Bakhanova, O.; Loganovs'kij, K.; Loganovs'ka, T.; Marazziti, D.

2015-01-01

This study aimed at investigating radiation exposure of hippocampus in interventional medical professionals irradiated in the operating room, and to compare doses in the hippocampus with the effective dose (protection quantity), as well as with the doses measured by individual dosimeter, in order to estimate probability of reaching levels of radiation induced cognitive and other neuropsychiatric alterations during their working career, through a Monte Carlo simulation. The results showed that cranial irradiation was very heterogeneous and depended on the projection: doses of left and right hippocampi may be different up to a factor of 2.5; under certain conditions, the dose of the left hippocampus may be twice the effective dose, estimated by conventional double dosimetry algorithm. The professional span doses of the irradiated hippocampus may overcome the threshold able to provoke possible cognitive and emotional-behavioral impairment. Therefore, in-depth studies of the effects of brain irradiation in occupationally exposed interventional medical personnel appear urgently needed and crucial

A new kind of radiation dose indicators for control of food irradiation processing

International Nuclear Information System (INIS)

Hoang Hoa Mai; Pham Duy Duong; Nguyen Dinh Duong; Kojima, T.

2007-01-01

A new kind of label dosimeters based on the polyvinyl butyral and dye compounds including leuco malachite green and methyl orange was developed for use as devices for discriminating and monitoring radiation treatment in food irradiation. The dosimeters change their color from orange-yellow to greenish under irradiation with gamma rays or electrons to dose just about 3 kGy. The greenish continue to develop to deep-green upon the increase of dose to 10 kGy. This makes the indicators useful for the dose range of food irradiation application, especially in treatment of frozen meat and sea products for elimination of micro-organism. The indicators were made in a stick-on label type showing attractive characteristics in use. The orange-yellow color before irradiation keep well stable under normal conditions in laboratory. The green after irradiation maintained as long as 6 months in practical conditions of products. New indicators can fill the gap in the demand of labeling indicators of food irradiation in our country as well as the world. (author)

ESR spectroscopy for detecting gamma-irradiated dried vegetables and estimating absorbed doses

Energy Technology Data Exchange (ETDEWEB)

Kwon, Joong-Ho; Chung, Hyung-Wook; Byun, Myung-Woo

2000-03-01

In view of an increasing demand for food irradiation technology, the development of a reliable means of detection for the control of irradiated foods has become necessary. Various vegetable food materials (dried cabbage, carrot, chunggyungchae, garlic, onion, and green onion), which can be legally irradiated in Korea, were subjected to a detection study using ESR spectroscopy. Correlation coefficients (R{sup 2}) between absorbed doses (2.5-15 kGy) and their corresponding ESR signals were identified from ESR signals. Pre-established threshold values were successfully applied to the detection of 54 coded unknown samples of dried clean vegetables (chunggyungchae, Brassica camestris var. chinensis), both non-irradiated and irradiated. The ESR signals of irradiated chunggyungchae decreased over a longer storage time, however, even after 6 months of ambient storage, these signals were still distinguishable from those of non-irradiated samples. The most successful estimates of absorbed dose (5 and 8 kGy) were obtained immediately after irradiation using a quadratic fit with average values of 4.85 and 8.65 kGy being calculated. (author)

The development of radiocaries after high-dose irradiation

International Nuclear Information System (INIS)

Willich, N.; Gundacker, K.; Rohloff, R.

1988-01-01

39 patients, who were irradiated with doses of 50 to 70 Gy for ENT-tumors over a period of 3.5 months to three years prior to the examination, showed a rapidly progressing caries of the teeth inside the target volume. The teeth outside the target volume developed a caries of less extent. Radiation induced xerostomia, effects of the irradiation of the soft tissues, nutrition habits and hygienics are discussed as causes for the damage of the teeth. (orig.) [de

Estimate of absorbed dose received by individuals irradiated with neutrons

International Nuclear Information System (INIS)

Fonseca, E.S. da; Mauricio, C.L.P.

1995-01-01

An innovating methodology is proposed to estimate the absorbed dose received by individuals irradiated with neutrons in an accident, even in the case that the victim is not using any kind of neutron dosemeter. The method combines direct measurements of 24 Na and 32 P activated in the human body. The calculation method was developed using data taken from previously published papers and experimental measurements. Other irradiations results in different neutron spectra prove the validity of the methodology here proposed. Using a whole body counter to measure 24 Na activity, it is possible to evaluate neutron absorbed doses in the order of 140 μGy of very soft (thermal) spectra. For fast neutron fields, the lower limit for neutron dose detection increases, but the present method continues to be very useful in accidents, with higher neutron doses. (author). 5 refs., 1 fig., 4 tabs

Irradiation preservation study on Beijing roast duck by low dose

Energy Technology Data Exchange (ETDEWEB)

Weiguo, Wang; Yongbao, Gu; Fengmei, Li [Beijing Normal Univ., BJ (China). Inst. of Low Energy Nuclear Physics; and others

1989-02-01

The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as {gamma}-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome.

Irradiation preservation study on Beijing roast duck by low dose

International Nuclear Information System (INIS)

Wang Weiguo; Gu Yongbao; Li Fengmei

1989-01-01

The irradiation technique combined with freezing has been used to control the microorganism in Beijing Roast Duck. Cobal-60 was chosen as γ-ray source. The absorbed dose was 2 kGy on an average. After irrdiation, the microbe counts have reached the tolerable. Compared with untreated ducks, the irradiated ones showed no remarkable change in nutrition, chemistry, vitamin etc. It has been proved through test that the irradiated frozen Beijing Roast Duck is wholesome

Statistical evaluation of the dose-distribution charts of the National Computerized Irradiation Planning Network

International Nuclear Information System (INIS)

Varjas, Geza; Jozsef, Gabor; Gyenes, Gyoergy; Petranyi, Julia; Bozoky, Laszlo; Pataki, Gezane

1985-01-01

The establishment of the National Computerized Irradiation Planning Network allowed to perform the statistical evaluation presented in this report. During the first 5 years 13389 dose-distribution charts were calculated for the treatment of 5320 patients, i.e. in average, 2,5 dose-distribution chart-variants per patient. This number practically did not change in the last 4 years. The irradiation plan of certain tumour localizations was performed on the basis of the calculation of, in average, 1.6-3.0 dose-distribution charts. Recently, radiation procedures assuring optimal dose-distribution, such as the use of moving fields, and two- or three-irradiation fields, are gaining grounds. (author)

Evaluation of build-up dose from 6 MV X-rays under pelvic and abdominal patient immobilisation devices

Energy Technology Data Exchange (ETDEWEB)

Cheung Tsang; Butson, M.J.Martin J. E-mail: mbutson@usa.netmbutson@guessmail.com; Yu, P.K.N

2002-06-01

The use of pelvic and abdominal immobilisation devices in radiotherapy is required for accurate positioning and repositioning of patients during their fractionated treatment delivered normally over a period of 5-6 weeks. 6 MV X-rays produced by a medical linear accelerator have a skin sparing effect whereby the skin dose delivered is considerably less than that received by the tumour. The treatment through a vacuum compressed immobilisation device (Vacbag) however increases the dose delivered to the skin by interactions of the X-rays within the Vacbag material. For example, the basal layer doses increased from 16% for an open field to 52% of maximum with a bag thickness of 2.5 cm for a 10 cmx10 cm field at 6 MV X-ray energy. At the same field size the dermal skin layer (1 mm depth) doses increased from 44% (no bag) to 60% for a bag thickness of 2.5 cm at 6 MV X-rays. The Vacbag should be placed outside the treatment field whenever possible to keep skin dose to a minimum level.

Evaluation of build-up dose from 6 MV X-rays under pelvic and abdominal patient immobilisation devices

International Nuclear Information System (INIS)

Cheung Tsang; Butson, M.J.Martin J.; Yu, P.K.N.

2002-01-01

The use of pelvic and abdominal immobilisation devices in radiotherapy is required for accurate positioning and repositioning of patients during their fractionated treatment delivered normally over a period of 5-6 weeks. 6 MV X-rays produced by a medical linear accelerator have a skin sparing effect whereby the skin dose delivered is considerably less than that received by the tumour. The treatment through a vacuum compressed immobilisation device (Vacbag) however increases the dose delivered to the skin by interactions of the X-rays within the Vacbag material. For example, the basal layer doses increased from 16% for an open field to 52% of maximum with a bag thickness of 2.5 cm for a 10 cmx10 cm field at 6 MV X-ray energy. At the same field size the dermal skin layer (1 mm depth) doses increased from 44% (no bag) to 60% for a bag thickness of 2.5 cm at 6 MV X-rays. The Vacbag should be placed outside the treatment field whenever possible to keep skin dose to a minimum level

Effect of the dose of irradiation on the conservation of the spice

International Nuclear Information System (INIS)

Ben Abdelkader, Houcine

2008-01-01

The effect of the gamma rays treatment emitted by a source of cobalt 60 in dose of 0, 3, 6 and 10 kGy on the microbiological and psycho-chemical properties of three samples of spice (hot pepper, fennel and coriander) have been studied. This study allowed us to measure the effect of these doses of irradiation on the lengthening of the lengthen conservation during storage of eight weeks to ambient temperature. The results show that the irradiation is very effective from a microbiological stand point. In fact, starting from 10 kGy the spices was not contaminated any more. The irradiation until a dose of dose 10 kGy has not generated any significant modifications, mainly in the physico-chemical parameters of the spices. But high diminishing has ac cured in water potency. Regarding colour variation, the irradiation has permitted the creation of a brighter colour for the three spices treated. A long the follow up we have an important multiplication in all bacteria existent in the three spices. Hew ever for the spices treated in 10 kGy we did not get any recontamination. (Author)

Effects of low dose irradiation on NK activity of normal individuals and patients with cancer

International Nuclear Information System (INIS)

Tian Hailin; Su Liaoyuan

1994-10-01

Effects of low dose irradiation on NK activity of lymphocytes and on K 562 cells were studied. The NK activity was determined by means of 3 H-TdR release assay. While 3 H-TdR incorporation was used to reflect functional changes of K 562 cells after low dose irradiation. 21 patients with cancer and 10 normal individuals were detected. The results indicated that the NK activity of lymphocytes in normal individuals increased significantly after 10 and 50 cGy γ-ray irradiation, while in patients with cancer the NK activity of lymphocytes increased only at the dose of 50 cGy irradiation. The increase of NK activity in normal individuals was higher than that in patients with cancer after same doses of irradiation. When K 562 cells were irradiated by 10 cGy γ-rays, the 3 H-TdR incorporation value increased. After exposed to over 50 cGy the stimulating effect disappeared

Influence of low dose irradiation on differentiation, maturation and T-cell activation of human dendritic cells

Energy Technology Data Exchange (ETDEWEB)

Jahns, Jutta [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany); Anderegg, Ulf; Saalbach, Anja [Department for Dermatology, Venerology and Allergology, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Rosin, Britt; Patties, Ina; Glasow, Annegret [Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany); Kamprad, Manja [Institute for Clinical Immunology and Transfusion Medicine, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Scholz, Markus [Institute for Medical Informatics, Statistics and Epidemiology, University of Leipzig, Haertelstr. 16-18, 04103 Leipzig (Germany); Hildebrandt, Guido, E-mail: Guido.Hildebrandt@uni-rostock.de [Department of Radiotherapy and Radiation Oncology, University of Rostock, Suedring 75, 18059 Rostock (Germany); Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig (Germany)

2011-05-10

Ionizing irradiation could act directly on immune cells and may induce bystander effects mediated by soluble factors that are released by the irradiated cells. This is the first study analyzing both the direct effect of low dose ionizing radiation (LDIR) on the maturation and cytokine release of human dendritic cells (DCs) and the functional consequences for co-cultured T-cells. We showed that irradiation of DC-precursors in vitro does not influence surface marker expression or cytokine profile of immature DCs nor of mature DCs after LPS treatment. There was no difference of single dose irradiation versus fractionated irradiation protocols on the behavior of the mature DCs. Further, the low dose irradiation did not change the capacity of the DCs to stimulate T-cell proliferation. But the irradiation of the co-culture of DCs and T-cells revealed significantly lower proliferation of T-cells with higher doses. Summarizing the data from approx. 50 DC preparations there is no significant effect of low dose ionizing irradiation on the cytokine profile, surface marker expression and maturation of DCs in vitro although functional consequences cannot be excluded.

Dose-volume effects in the rat cervical spinal cord after proton irradiation

International Nuclear Information System (INIS)

Bijl, Hendrik P.; Vuijk, Peter van; Coppes, Rob P.; Schippers, Jacobus M.; Konings, Antonius W.T.; Kogel, Albert J. van der

2002-01-01

Purpose: To estimate dose-volume effects in the rat cervical spinal cord with protons. Methods and Materials: Wistar rats were irradiated on the cervical spinal cord with a single fraction of unmodulated protons (150-190 MeV) using the shoot through method, which employs the plateau of the depth-dose profile rather than the Bragg peak. Four different lengths of the spinal cord (2, 4, 8, and 20 mm) were irradiated with variable doses. The endpoint for estimating dose-volume effects was paralysis of fore or hind limbs. Results: The results obtained with a high-precision proton beam showed a marginal increase of ED 50 when decreasing the irradiated cord length from 20 mm (ED 50 = 20.4 Gy) to 8 mm (ED 50 = 24.9 Gy), but a steep increase in ED 50 when further decreasing the length to 4 mm (ED 50 = 53.7 Gy) and 2 mm (ED 50 = 87.8 Gy). These results generally confirm data obtained previously in a limited series with 4-6-MV photons, and for the first time it was possible to construct complete dose-response curves down to lengths of 2 mm. At higher ED 50 values and shorter lengths irradiated, the latent period to paralysis decreased from 125 to 60 days. Conclusions: Irradiation of variable lengths of rat cervical spinal cord with protons showed steeply increasing ED 50 values for lengths of less than 8 mm. These results suggest the presence of a critical migration distance of 2-3 mm for cells involved in regeneration processes

Quality characteristics of mechanically deboned chicken meat irradiated with different dose rates

Energy Technology Data Exchange (ETDEWEB)

Brito, Poliana de Paula; Roque, Claudio Vitor; Fukuma, Henrique Takuji; Gomes, Heliana de Azevedo [Brazilian Nuclear Energy Commission (CNEN-MG), Pocos de Caldas, MG (Brazil)]. E-mails: polibrito@yahoo.com.br; cvroque@cnen.gov.br; htfukuma@cnen.gov.br; hgomes@cnen.gov.br; Cipolli, Katia Maria Vieira Avelar Bittencourt [Sao Paulo Agribusiness Technology Agency (APTA), Monte Alegre do Sul, SP (Brazil). Polo Regional do Leste Paulista]. E-mail: katiacipolli@aptaregional.sp.gov.br; Pereira, Jose Luiz [Campinas State University UNICAMP, Campinas, SP (Brazil). Dept. of Food Sciences]. E-mail: pereira@fea.unicamp.br

2007-07-01

Mechanically Deboned Chicken Meat (MDCM) is a low cost raw material used in the production of emulsified prepared food, but presents a favorable medium for development of microorganisms. Several studies were carried out with irradiation of edible goods in order to establish a dose that would be capable of decreasing levels of microorganisms without altering the sensorial and nutritional characteristics of the food. Frozen samples of MDCM with skin were irradiated with doses of 0.0 kGy, 3.0 kGy-4.04 kGy.h{sup -1}, and 3.0- 0.32 kGy.h{sup -1}. Individual lots of irradiated and control samples were evaluated during the 11 day refrigeration period for the following parameters: total count of psychotropic bacteria, substances reactive to Thiobarbituric Acid, sensorial evaluation (irradiated odor, oxidized odor, pink and brown colors). The average values in this period were 4.28 log (CFU.g{sup -1}), 2.32 log (CFU.g{sup -1}), and 1.68 log (CFU.g{sup -1}) for control samples, low and high dose rate, respectively. TBARS average values for control samples, low and high dose rate were 0.38 mg.Mal.kg{sup -1}, 2.89 mg.Mal.kg{sup -1}, and 3.64 mg.Mal.kg{sup -}'1, respectively. A difference between irradiated samples and the control sample was observed. The 3.0 kGy-4.04 kGy.h{sup -1} dose rate was verified as the best condition for MDCM processing through the evaluation of all the variables in the conditions of the present study. (author)

Dose-effect curves for electron-beam irradiation of some collection microbial strains

International Nuclear Information System (INIS)

Ferdes, O.; Dumitru, E.; Catargiu, L.; Ferdes, M.; Minea, R.; Oproiu, C.; Niculescu, A.

1994-01-01

There were electron-beam irradiated some microbial strains of B.subtilis ICA I-60 both in germination and in sporulated forms. The irradiation were performed at the IPTRD's electron accelerator at 6 MeV, and in the dose range between 0.1-5.0 kGy, at different dose-rate varying from 50 Gy/minute to 100 Gy/minute. The dosimetry was carried out by a PTW medical dosemeter. There were established the dose-effect relationships and curves, the inactivation dose (factor) and the optimum domain for electron-beam mutagenesis. There were obtained some mutant strains with 2-3.5 higher biosynthesis potential, which are in the IFC's collection. (Author)

Computational analysis of the dose rates at JSI TRIGA reactor irradiation facilities.

Science.gov (United States)

Ambrožič, K; Žerovnik, G; Snoj, L

2017-12-01

The JSI TRIGA Mark II, IJS research reactor is equipped with numerous irradiation positions, where samples can be irradiated by neutrons and γ-rays. Irradiation position selection is based on its properties, such as physical size and accessibility, as well as neutron and γ-ray spectra, flux and dose intensities. This paper presents an overview on the neutron and γ-ray fluxes, spectra and dose intensities calculations using Monte Carlo MCNP software and ENDF/B-VII.0 nuclear data libraries. The dose-rates are presented in terms of ambient dose equivalents, air kerma, and silicon dose equivalent. At full reactor power the neutron ambient dose equivalent ranges from 5.5×10 3 Svh -1 to 6×10 6 Svh -1 , silicon dose equivalent from 6×10 2 Gy/h si to 3×10 5 Gy/h si , and neutron air kerma from 4.3×10 3 Gyh -1 to 2×10 5 Gyh -1 . Ratio of fast (1MeVreactor power from 3.4×10 3 Svh -1 to 3.6×10 5 Svh -1 and γ air kerma range 3.1×10 3 Gyh -1 to 2.9×10 5 Gyh -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

High dose radiation damage in nuclear energy structural materials investigated by heavy ion irradiation simulation

International Nuclear Information System (INIS)

Zheng Yongnan; Xu Yongjun; Yuan Daqing

2014-01-01

Structural materials in ITER, ADS and fast reactor suffer high dose irradiations of neutrons and/or protons, that leads to severe displacement damage up to lOO dpa per year. Investigation of radiation damage induced by such a high dose irradiation has attracted great attention along with the development of nuclear energy facilities of new generation. However, it is deeply hampered for the lacking of high dose neutron and proton sources. Irradiation simulation of heavy ions produced by accelerators opens up an effective way for laboratory investigation of high dose irradiation induced radiation damage encountered in the ITER, ADS, etc. Radiation damage is caused mainly by atomic displacement in materials. The displacement rate of heavy ions is about lO 3 ∼10 7 orders higher than those of neutrons and protons. High displacement rate of heavy ions significantly reduces the irradiation time. The heavy ion irradiation simulation technique (HIIS) technique has been developed at China Institute of Atomic Energy and a series of the HIIS experiments have been performed to investigate radiation damage in stainless steels, tungsten and tantalum at irradiation temperatures from room temperature to 800 ℃ and in the irradiation dose region up to 100 dpa. The experimental results show that he radiation swelling peak for the modified stainless steel appears in the temperature region around 580 ℃ and the radiation damage is more sensitive to the temperature, the size of the radiation induced vacancy cluster or void increase with the increasing of the irradiation dose, and among the three materials the home-made modified stainless steel has the best radiation resistant property. (authors)

Irradiation dose control of chicken meat processing with alanine/ESR dosimetric system

International Nuclear Information System (INIS)

Miyagusku, L.; Chen, F.; Kuaye, A.; Castilho, C.J.C.; Baffa, O.

2007-01-01

Irradiation of foodstuff is a well-known food preservation technique. In Brazil spices are already irradiated for sanitary and preservation reasons. Chicken meat is an important commodity; Brazil is the second largest world producer and the largest world exporter. The shelf-life of chicken meat is limited by the presence of micro-organisms and enzyme activity and together with other preservation techniques irradiation seems to be an attractive option. In this study the dose delivered to frozen chicken cuts was measured and compared with the prescribed value. Chicken breast cuts were analyzed for 39 days for their microbiological activity, chemical and organoleptic properties. Cylindrical dosimeters were prepared using the weight composition of 80% of DL-alanine (Sigma Co), used without any further treatment except drying, and 20% of paraffin. The dosimeters having 4.7 mm diameter and 12 mm length were inserted in a build-up cap. Dosimeters were placed inside cardboard boxes containing frozen chicken breast cuts, packed in styrofoam trays wrapped with plastic film. The boxes were irradiated in an industrial 60 Co irradiator (Nordion JS 7500) with a dose rate of 4 kGy/h. First derivative ESR signals were obtained in a VARIAN E-4 spectrometer operating at X-band (ν∼9GHz) and equipped with a rectangular cavity (TE-102, model E-231). The cavity was constantly purged with dry nitrogen and modulated at 100 KHz with 0.5 mT peak to peak. A calibration curve was made for a few dosimeters from the same batch and used to obtain the dose from the ESR signal intensity. A batch of six boxes was irradiated at each experiment with prescribed doses of 1.5, 3.0 and 7.0 kGy. Considering that the larger the radiation dose the greater is the probability of finding a product with its sensorial characteristics altered (odor of burned meat), we conclude that a dose of 3 kGy would be more adequate, taking into account the microbiological and sensorial aspects