Forty-four patients with histologically proven Hodgkin's disease underwent initial treatment with extended-field radiationtherapy. Nineteen of these patients also received combination chemotherapy....Full Text Available
The incidence of hilar cholangiocarcinoma is very rare worldwide. Radical resection is the only prognostic factor for long survival in patients with hilar cholangiocarcinoma. Postoperative radiationtherapy can improve local control and survival rates for patients with palliative resection, but it remains controversial in patients with radical resection. Biliary drainage can effectively release bile duct obstruction for the majority of patients with locally advanced disease, and may even prolong survival when combined with radiationtherapy. Radiationtherapy includes extrernal beam therapy alone, external beam therapy with intraluminal brachytheapy and new radiation technique, such as three dimentional conformal therapy and intensity modulated ...
Prostate cancer can be successfully treated using dynamic adaptive external beam radiation techniques along with interstitial brachytherapy to deliver curative therapies with low urinary, rectal and erectile function morbidity. Through the use of sophisticated, state-of-the art radiographic imaging for staging and treatment planning, a precise, individual design for treatment is accomplished. Symptom management and patient education are of paramount importance and are integrated throughout the treatment process.
Abstract The authors provide a survey of how images are used in radiationtherapy to improve the precision of radiationtherapy plans, and delivery of radiation treatment. In contrast...Full Text Available
... radiation during clinical therapy and exposures due to radiation accidents or attacks, in which the doses are uncontrolled ... only be used off-label in victims of radiation accidents or attacks. The idea...
A long-term follow-up of a patient with beta thalassaemia with intra- and extraspinal extramedullary haematopoietic tissue compressing the spinal cord is presented. Extramedullary haematopoietic nodules are a rare cause of spinal cord compression and should be included in the differential diagnosis, especially in patients from Mediterranean countries. Treatment with radiationtherapy solely failed, giving rise to the need of surgical intervention. Surgical decompression of the spine and the removal of the culprit lesion compressing the spine were performed. Postinterventional radiationtherapy was applied to the spine. A relapse had to be treated again by surgical means combined with postinterventional radiationtherapy. A complete relief of the symptoms and control of the lesion could be obtained.
The outcome was retrospectively examined and prognostic factors were discussed for arterial chemo-infusion therapy (ACT) through an implanted reservoir system and radiationtherapy (RT) in patients with unresectable intrahepatic cholangiocarcinoma (CCC). ACT plus RT were conducted to 25 patients (mean age 61.7 y, M/F 12/13, stage III-IVB) during 10 years from 1996 to 2005 with various regimens of cisplatin (CDDP), 5- fluorouracil (FU), epirubicin (FARM), mitomycin C (MMC) plus 39-50 Gy of radiation in a fractionated manner partly involving internal RT (2 cases, 15 Gy) and RT for metastatic bone (1, 25 Gy). The survival rates at 1, 2 and 3 years after ACT+RT were respectively 52.5, 43.7 and 28.1%; total efficacy (PR) was 36% (9/25) at 6 months; and significantly good prognostic factors were found to be female and absence of metastasis remote and/or lymphatic around artery. Authors concluded that ACT+RT ...
The results of 144 previously untreated cases of primary Ewing's sarcoma of bone are reported with a minimum follow-up of 5 years. This series was treated between 1972 and 1982 at Istituto Ortopedico Rizzoli with a combinedtherapy. The local control of the disease consisted of amputation (ten cases), resection followed by radiationtherapy (35-45 Gy) (48 cases) and radiationtherapy alone (40-60 Gy) (86 cases). Adjuvant chemotherapy, rigorously standardized, was performed according two different protocols: the first (85 cases treated in the period 1972-1978) consisted of vincristine (VCR) Adriamycin (doxorubicin) (ADM), and cyclophosphamide (EDX); the second (59 cases treated in the period 1979-1982) of VCR, ADM, EDX and dactinomycin (DACT). At a follow-up of 5 to 16 years (median, 9), 59 patients (41%) are continuously disease-free (CDF), 81 (56%) developed ...
Retrospective analyses were performed to evaluate the therapeutic efficacy of intra-oral cone (IOC) radiationtherapy for carcinoma of the oral tongue, especially about its faculty of local control and complications. Thirty-nine patients with squamous cell carcinoma of the oral tongue were treated with IOC radiationtherapy alone or in combination with external irradiation. IOC radiationtherapy was given not only for T1 and T2, but also for T3 tumors. Hypofractionation was used for IOC radiationtherapy. The 2 year local control rates, including surgical salvage, for T1, T2, T3 and T4 were 100%, 73.3%, 40% and 0%, respectively. The 5 year actuarial survival rates for Stage I, II, III and IV were 100%, 65.3%, 35.4% and 0%, respectively. The incidences of radiation complications, ...
The clinical results of electron beam therapy using intraoral cone in 8 cases of primary and recurrence carcinoma of tongue (T1 and smaller T2) were reported. The primary and recurrence cases were 5 and 3, respectively. In the 5 cases, a total dose of 10-30 Gy external radiationtherapy were combined prior to electron beam therapy. The total dose of electron beam therapy varied from 40 to 60 Gy. In all cases, tumor showed good response and disappeared clinically. Radiation stomatitis, pain of the tongue with masticatory disturbance due to tenderness were complicated in all cases. These complications gradually disappeared 2 to 6 months after treatment. However, loss of body weight and bone exposure were not recognized in any case. Intraoral-cone electron beam therapy is thought to be available and has less complications ...
Purpose: To evaluate the effect of low-dose radiationtherapy and surgery on local control in patients with Ewing's Sarcoma. Materials and Methods: Between 1979 and 1995 24 patients (ages 4-47) with Ewing's sarcoma were treated with combined modality therapy that included multi agent chemotherapy, surgical resection, and radiationtherapy. Twelve patients had metastatic disease at the time of presentation (pleura = 3, lung = 5, bone 4). Tumor location was central in 16 and peripheral in 8. Multi agent chemotherapy consisted of vincristine/actinomycin D/cyclophosphamide/doxorubicin in 19. The same agents with the addition of ifosfamide and etoposide were given in 5. The extent of resection was considered to be radical in 14 and of the 16 patients who received preoperative chemotherapy, 5 were found to have a pathologic complete response. All patients with lung ...
From 1979 to 1986, 182 patients with biopsy proven diagnosis of Ewing's sarcoma of bone were observed. One hundred of the 182 patients (72 males, 28 females, median age 15.8 years) with localized disease and no previous treatment were treated with chemotherapy (VCR, ADM, CTX, D-ACT) for 15-18 months. Local treatment was radiotherapy (42 patients), surgery (31 patients), or a combination of both (27 pts). Radiation doses ranged from 45 to 64 Gy given with conventional fractionation. Median follow-up was 51.2 months (24-106). Overall and disease-free survival were, respectively, 58.7 and 42.6%. Resected patients tended to have a better local control (Surgery 93.6%, Surgery + Radiationtherapy 92.6%, Radiationtherapy 69.1%). Disease-free survival was significantly related to the volume of the primary tumor (bulky: 33.2%, not-bulky: 57.7%), to site (extremities ...
Purpose: The purpose of this study was to evaluate the efficacy and toxicity of replication-competent adenovirus-mediated double suicide gene therapy in an adjuvant setting with external beam radiationtherapy (EBRT) in an experimental prostate cancer model in preparation for a Phase I clinical study in humans. Methods: For efficacy studies, i.m. DU145 and intraprostatic LNCaP C4-2 tumors were established in immune-deficient mice. Tumors were injected with the lytic, replication-competent Ad5-CD/TKrep adenovirus containing a cytosine deaminase (CD)/herpes simplex virus thymidine kinase (HSV-1 TK) fusion gene. Two days later, mice were administered 1 week of 5-fluorocytosine + ganciclovir (GCV) prodrug therapy and fractionated doses of EBRT (trimodal therapy). Tumor control rate of trimodal therapy was compared to that of EBRT alone. For toxicology studies, ...
Advances in the diagnosis of Ewing's sarcoma of the rib were considered and retrospective analysis of the treatment of 32 patients (76% of them were children at the age of 10-15 y.o.) in the clinic of children oncology was performed. It was shown that the diagnosis of Ewing's sarcoma of the rib in children ought to be combined taking into account the course, morphology and radiation examination techniques. Most optimum treatment consisted of combinedtherapy (cyclic polychemotherapy, lesion focus irradiation at the summary focus dose of 57 Gy, surgery with subsequent polychemotherapy for not less than 1.5 years
Oral mucositis associated with head and neck radiotherapy can substantially hinder completion of cancer therapy. Alleviation of this often severe stomatitis can provide enhanced patient comfort and facilitate appropriate care. A double-blind format was used in a pilot project to measure, against a control rinse, the effectiveness of an oral rinse consisting of hydrocortisone, nystatin, tetracycline, and diphenhydramine in controlling radiation-related mucositis. A combination of clinical evaluation and patient responses to a questionnaire was used to judge the results of the topical medications. Patients using the experimental medication developed less mucositis than did patients in the control group.
BackgroundTo compare two strategies of dynamic intensity modulated radiationtherapy (dIMRT) with 3-dimensional conformal radiationtherapy (3DCRT) in the setting of hypofractionated...Full Text Available
Adaptive radiationtherapy (ART) is the incorporation of daily images in the radiotherapy treatment process so that the treatment plan can be evaluated and modified to maximize the amount of radiation...Full Text Available
ObjectiveTo report the efficacy and safety of combined photodynamic therapy (PDT) and intravitreal bevacizumab (IVB) injection in the treatment of idiopathic polypoidal choroidal...Full Text Available
Radiationtherapy has shown definite technical improvement due to application of proton beam irradiation. Clinical results of proton beam therapy also suggested enlargement of indication ranges in radial treatment and decrease of post radiation damages of the treatment of cancers in deep-seated organs. Inprovement of result in cancer therapy could be expected by this treatment technique in the future.
BackgroundThe aim of this study was to compare and to validate different dose calculation algorithms for the use in radiationtherapy of small lung lesions and to optimize the treatment...Full Text Available
Purpose: Understanding the kinetics of tumor growth∕shrinkage represents a critical step in quantitative assessment of therapeutics and realization of adaptive radiationtherapy....Full Text Available
PurposeA dosimetric comparison between multiple static-field intensity-modulated radiationtherapy (IMRT), multi-arc intensity-modulated arc therapy (IMAT) and single-arc...Full Text Available
In many radiotherapy clinics, geometric uncertainties in the delivery of 3D conformal radiationtherapy and intensity modulated radiationtherapy of the prostate are reduced by aligning the...Full Text Available
A human cholangiocarcinoma, Ch-1, serially transplanted to nude mice was used for experimental chemotherapy, radiotherapy, and conbination chemoradiotherapy. In the group of chemotherapy with single drug, Mitomycin C (MMC) revealed greater effectiveness than Adriamycin in terms of tumor regression, histological findings, and minor side effects. MMC and radiotherapy by Linac X-ray showed exponential linear dose response curve against tumor weight. Their effects were equivalent at doses of MMC 1 mg/kg and radiation 1,000 rads/mouse in the changes of tumor weight and of histological findings which were similar to each other. Combination chemoradiotherapy showed the synergistic action when the radiation (500 rads/mouse) was performed before MMC (0.5 mg/kg) administration, whereas only the additive effect was observed when the sequence was reversed. The cell kinetic analysis was performed by the impulse cytophotometry, ...
Some studies suggest that giving radiationtherapy after surgery for hilar cholangiocarcinoma improves the survival rate; however, many of these studies did not specify numbers of subjects or provide an impartial analysis. Thus, we evaluated the effectiveness of radiationtherapy as adjuvant treatment after surgery and attempted to establish appropriate adaptation standards. We reviewed the records of 69 patients who underwent surgery for hilar cholangiocarcinoma between June 1980 and April 1998. Thirty-nine patients were treated with surgery followed by radiationtherapy and 30 were treated with surgery alone. The clinicopathologic features that might have influenced prognosis were similar in the patients who received radiationtherapy and those who did not. Radiation as adjuvant ...
Background: EGFR (epidermal growth factor receptor) and VEGF (vascular endothelial growth factor) inhibitors confer clinical benefit in metastatic colorectal cancer when combined with chemotherapy. An emerging strategy to improve outcomes in rectal cancer is to integrate biologically active, targeted agents as triple therapy into chemoradiation protocols. Material and methods: cetuximab and bevacizumab have now been incorporated into phase I-II studies of preoperative chemoradiation therapy (CRT) for rectal cancer. The rationale of these combinations, early efficacy and toxicity data, and possible molecular predictors for tumor response are reviewed. Computerized bibliographic searches of Pubmed were supplemented with hand searches of reference lists and abstracts of ASCO and ASTRO meetings. Results: the combination of cetuximab and CRT can be safely applied without dose compromises ...
In August 1982, a 44-year-old man was diagnosed as having rectal cancer, histologically diagnosed as well differentiated adenocarcinoma, and abdominoperineal resection and colostomy were performed. Postoperatively, he received chemotherapy with mitomycin C up to a total dose of 100 mg. In September 1986, lung metastasis occurred and he was treated with a combination chemotherapy consisting of cisplatin, pirarubicin and 5-fluorouracil. In the following year, radiation treatment (total: 6900 rad) was given for a recurrent pelvic lesion. Peripheral blood on April 30, 1988, showed anemia, thrombocytopenia and appearance of myeloblasts, and a diagnosis of acute myelogenous leukemia (FAB: M1) was made. Combination chemotherapy (including aclarubicin, vincristine, behenoyl ara-C, daunorubicin, 6-mercaptopurine, cytarabine, etoposide and prednisolone) failed to induce remission and the patient died in June 1988. This case was ...
The patient positioning and repositioning control in radiationtherapy all along the treatment can be conducted using a variety of X-ray sources and imaging detector devices. The development of image guided radiationtherapy techniques leads to more frequent use of this imaging control. In this article we summarize the current methods for measuring the dose delivered by X-ray imaging devices used in radiationtherapy, as well as basic proposals to take account of these imaging doses for prescribing, recording and reporting radiationtherapy treatment. (authors)
The proton therapy gives an irradiation adapted to the shape and the depth of tumors ( eyes, head and neck) with a millimetric, even sub millimetric precision for the ophthalmological tumors. It is equally an excellent tool for the pediatrics tumors. For numerous treatments in France the proton therapy is associated to the photons treatments (x radiation). however, others physical treatments could modulate the medical offer, such thermal therapy or treatments by ultrasonic waves. (N.C.)
Radiationtherapy has had a significant and an expanded role in the management of cancer of the pancreas during the last decade. In particular, for locally advanced disease, radiationtherapy has improved the median survival of patients to 1 year. Intraoperative electron beam therapy has been applied to unresectable and resectable pancreatic cancer in an attempt to enhance local control of disease and to improve patient survival. This paper presents a survey of the role of radiationtherapy in treatment of cancer of the pancreas, provides information on the radiobiological aspects of this treatment modality and details the physical and dosimetric characteristics of intraoperative radiationtherapy with electrons. Presented are the design specifics of an applicator system, central axis beam data, ...
Radiationtherapy has had a significant and an expanded role in the management of cancer of the pancreas during the last decade. In particular, for locally advanced disease, radiationtherapy has improved the median survival of patients to 1 year. Intraoperative electron beam therapy has been applied to unresectable and resectable pancreatic cancer in an attempt to enhance local control of disease and to improve patient survival. This paper presents a survey of the role of radiationtherapy in treatment of cancer of the pancreas, provides information on the radiobiological aspects of this treatment modality and details the physical and dosimetric characteristics of intraoperative radiationtherapy with electrons. Presented are the design specifics of an applicator system, central axis beam data, ...
BackgroundAdolescents have been identified as a high-risk group for poor adherence to and defaulting from combination antiretroviral therapy (cART) care. However, data on outcomes...Full Text Available
BackgroundArtemisinin-based combinationtherapy, currently considered the therapy of choice for uncomplicated Plasmodium falciparum malaria in endemic countries,...Full Text Available
Purpose: Treatment results and the pattern of relapse were evaluated in the multimodal treatment of Ewing's sarcomas of the chest wall. Methods and Materials: In a retrospective analysis, 114 patients with non-metastatic Ewing's sarcoma of the chest wall were evaluated. They were treated in the CESS 81, CESS 86, or EICESS 92 studies between January 1981 and December 1993. The treatment consisted of polychemotherapy (VACA, VAIA, or EVAIA) and local therapy, either surgery alone (14 patients), radiotherapy alone (28 patients) or a combination of both (71 patients). The median follow-up was 46.6 months (range 5-170). A relapse analysis for all patients with local or combined relapses was performed. Results: Overall survival was 60% after 5 years, event-free survival was 50%. Thirty-seven patients had a systemic relapse (32.4%), 11 patients had a local relapse alone (9.6%), and 3 patients had a combined ...
Several compact proton accelerator systems for use in proton therapy have recently been proposed. Of paramount importance to the development of such an accelerator system is the maximum kinetic energy...Full Text Available
Thyroid cancer is the most frequently diagnosed endocrine cancer and causes more deaths than all other endocrine cancers combined. Research findings support the concept that a subpopulation of thyroid cancer cells displays properties characteristic of stem cells. These putative cancer-forming entities drive tumorigenesis as a result of their dual ability to undergo self-renewal and to differentiate into various types of cancer cells; they also mediate metastasis and are resistant to the effects of chemotherapy and radiationtherapy. This Review discusses the cellular origin of thyroid cancer and the properties of the thyroid cancer stem cell niche. The article critically evaluates the methods used to identify molecular markers expressed by thyroid-cancer-initiating cells and outlines prosp...
Between 1964 and 1977, 94 patients with Ewing's sarcoma of bone were treated at the National Cancer Institute. They received 5000 rad to the whole bone and progressively more aggressive chemotherapy protocols. The patients were divided according to site of primary lesion into central, proximal and distal lesions, with 19%, 33% and 57%, respectively, alive and well. The local control rate is high (93%), with good functional results in the distal lesions, and no changes are needed in radiationtherapy dose or volume. Control is not as satisfactory for central and proximal lesions and efforts need to be made to increase control at these sites. We are at present attempting to define more accurately the extent of soft tissue disease, increasing the dose to 6000 rad for central lesions, and using a more aggressive chemotherapy program, in the hope of increasing the local control in these more aggressive tumors.
Summary: The increasing emergence of antimicrobial-resistant organisms, especially methicillin-resistant Staphylococcus aureus (MRSA), has resulted in the increased...Full Text Available
Conformal radiationtherapy represents a considerable and attractive challenge in oncology. Its aim is mainly to improve local control by increasing the dose with an acceptable rate of complications. This work overviews the world literature on this subject. The technical and theoretical requirements are highlighted. These requirements include a precise definition of the target volume by digital imaging (essentially CT scan), but also clear view of the target volume and the organs at risk, a specific collimation of the beam, 3-D dose calculations, optimization procedures, and a rigid immobilization of the patient with verification of his position. Moreover, the clinical applications of conformal radiationtherapy are reviewed and discussed. (authors). 80 refs., 1 tab.
Gastrointestinal lymphomas are almost exclusively of a non Hodgkin's type. The Western form is characterized by a higher incidence of stomach location (50 %), a MALT type (mucosa associated lymphoid tissue) (40 %), a B-cell type (90 %), and a high grade (55 %). Chronic infection with Helicobacter pylori is an important risk factor. Mediterranean lymphomas form a particular clinical and pathological entity with diffuse involvement of the small bowel and are frequently being associated with a chronic malabsorption disorder. Eradication of Helicobacter pylori in early lymphomas, and the use of tetracyclines in early Mediterranean lymphomas, have been shown to induce durable remissions. For more advanced gastric lymphomas, treatment usually consists of anthracycline-based chemotherapy followed by involved field radiotherapy. Surgery is usually reserved for complications such as perforation or bleeding, or in some selected cases for salvage after failure of non-surgical ...
Despite high local control rate in Ewing's sarcoma the exact indication of radiationtherapy is still controversial as well as the choice of the target volume and the optimal dose of radiation. The importance of the quality of radiotherapy has been stressed in recently published data and has shown a significant impact on long term local control with adequate radiationtherapy. The dramatic improvement of precision allowed by the conformal therapy and three dimensional dosimetry allow to expect a decrease of late effects expected for second malignancies. However, late sequelae and radio-induced osteosarcoma still remain the major side effects after radiotherapy. The authors discuss the results of the main trials on Ewing's sarcoma on the choice of dose and target volume. Surgery is still the preferred choice for small tumors if the foreseen outcome is identical. ...
Modern advances in the concept and the techniques of megavoltage radiationtherapy have revolutionized the treatment of medulloblastoma. Five-year survivals of 50 to 70 percent are achieved by craniospinalaxis...Full Text Available
Development of Portable Normobaric Hypoxia and Pulsed Magnetic Field Firmware System for Enhancement of Radio- and Non-specific Resistance in Workers of Environmentally Hazardous Industries
Previous research with individuals undergoing surgery or diagnostic procedures provided a conceptual framework for analysis of radiationtherapy, a common form of cancer treatment. The present...Full Text Available
Adaptive radiationtherapy for liver cancer has the potential to reduce normal tissue complications and enable dose escalation, allowing the potential for tumor control in this challenging site....Full Text Available
Purpose: We present an update analysis of the multiinstitutional Ewing's sarcoma study CESS 86. Methods and Materials: From January 1986 through June 1991, 177 patients with localized Ewing's sarcoma of bone, aged 25 years or less, were recruited. Chemotherapy consisted of four 9-week courses of vincristine, actinomycin D, cyclophosphamide, and adriamycin (VACA) in low-risk tumors (extremity tumors =# 100 cm"3). Local therapy was an individual decision in each patient and was either radical surgery (amputation, wide resection) or resection plus postoperative irradiation with 45 Gy or definitive radiotherapy with 60 Gy (45 Gy plus boost). Irradiated patients were randomized concerning the type of fractionation in either conventional fractionation (once daily 1.8-2.0 Gy, break of chemotherapy) or hyperfractionated split-course irradiation simultaneously with the VACA/VAIA chemotherapy (twice daily 1.6 Gy, break of 12 days after 22.4 Gy and 44.8 Gy, total dose and ...
Ovarian function was evaluated in 11 women 16 to 43 years of age at treatment who received doxorubicin, cyclophosphamide, and high doses of methotrexate with or without radiotherapy in adjuvant therapy of soft tissue sarcoma. Five women (16-33 yr old) who received chemotherapy alone or combined with radiotherapy only at sites distant from the ovaries (chest wall, thigh, and leg) had minimal menstrual irregularities or temporary cessation of menses during therapy; cyclic menses returned promptly after therapy. Gonadotropin levels (expressed as means +/- SD) (follicle-stimulating hormone (FSH), 10 +/- 15 mlU/ml; luteinizing hormone (LH), 10 +/- 4 mlU/ml) and 17 ..beta..-estradiol (E/sub 2/) levels (means +/- SD, 208 +/- 147 pg/ml) were normal. By contrast, 4 older women (ages 36-43 yr) who received similar treatment developd persistent amenorrhea with postmenopausal levels of gonadotropin (FSH, 109 +/- 29 ...
Ovarian function was evaluated in 11 women 16 to 43 years of age at treatment who received doxorubicin, cyclophosphamide, and high doses of methotrexate with or without radiotherapy in adjuvant therapy of soft tissue sarcoma. Five women (16-33 yr old) who received chemotherapy alone or combined with radiotherapy only at sites distant from the ovaries (chest wall, thigh, and leg) had minimal menstrual irregularities or temporary cessation of menses during therapy; cyclic menses returned promptly after therapy. Gonadotropin levels (expressed as means +/- SD (follicle-stimulating hormone (FSH), 10 +/- 5 mlU/ml; luteinizing hormone (LH), 10 +/- 4 mlU/ml) and 17 beta-estradiol (E2) levels (means +/- SD, 208 +/- 147 pg/ml) were normal. By contrast, 4 older women (ages 36-43 yr) who received similar treatment developed persistent amenorrhea with postmenopausal levels of gonadotropin (FSH, 108 +/- 29 mlU/ml; ...
The invention refers a procedure of radiation dose control in irradiated tissues during electron-beam therapy. It aims at meeting the planned radiation dose for diseased tissues and taking care of the healthy ones. Therefore, the dose distribution required is determined before irradiation in consideration of such factors as energy-dependence of detector sensitivity, self-absorption within the tissue, and relative biological effectiveness. Furthermore, the expected intensity distribution of secondary quantum radiation excited in the irradiated tissue is calculated. A radiation detector for local resolution is used for registration. During irradiation the calculated intensity distribution is compared with the measured one. The invention is applicable in radiationtherapy with monoenergetic electron beams.
This text-book (electronic book - multi-media CD-ROM) constitutes a course-book - author's collection of lectures. It consists of 13 lectures in which the reader acquaints with the basis of radiobiology: Introduction to radiobiology; Physical fundamentals of radiobiology; Radiation of cells; Modification of radiation damage of cells; Reparation of radiation damage of cells; Radiation syndromes and their modification; Radiation injury; Radiation damage of tissues; Effect of radiation on embryo and fetus; Biological effects of incorporated radionuclides; Therapy of acute irradiation sickness; Delayed consequences of irradiation; Radiation oncology and radiotherapy. This course-book may be interesting for students, post-graduate students of chemistry, biology, physics, medicine as well as for teachers, ...
Purpose: To assess the relationship between large intracranial vessel occlusive vasculopathy (vasculopathy) and radiationtherapy, and to clarify the clinical efficacy of magnetic resonance (MR) imaging in the diagnosis and screening of the vasculopathy. Methods and Materials: We retrospectively evaluated the medical records and serial MR images for 32 pediatric patients, in whom radiationtherapy had been given to fields including the circle of Willis and major cerebral arteries. All children had periodically undergone follow-up neurologic assessment and MR imaging examinations at Kanagawa Children's Medical Center for more than one year after radiationtherapy (range 1.3-14 years). Patients who had not remained free of tumor progression up to the time of final evaluation were excluded. Results: Vasculopathy developed in 6 of 32 patients 2-13 years after ...
The problem of optimizing a horn radiator of electromagnetic waves for the reflection coefficient and the coefficient of transformation of the fundamental mode into higher order modes is solved. Optimization is performed by means of selecting a combined shape of the radiator generatrices.
PurposeWe conducted a comparative study of Clinical Target Volume (CTV) definition of pelvic lymph nodes by multiple GU radiation oncologists looking at the levels...Full Text Available
For intensity modulated radiation treatment (IMRT) dose reconstruction, multileaf collimator (MLC) log files have been shown applicable for deriving delivered fluence maps. However, MLC log files are...Full Text Available
Prostatic neoplasms are not uniformly distributed within the prostate volume. With recent developments in three-dimensional intensity-modulated and imageguided radiationtherapy, it is possible to treat...Full Text Available
Two patients who developed large intracranial vessel occlusion after standard radiationtherapy for brain tumor are described. This form of vascular occlusion is usually seen in patients who have previously been treated by radiotherapy for intracranial tumor who then develop a relatively acute change in neurologic status. Histology of the lesion mimics accelerated focal arteriosclerosis. The clinical and radiographic manifestations of one case were highly atypical. The vasculopathy became evident shortly after termination of radiationtherapy for a fourth ventricular ependymoma, and the angiographic picture stimulated a diffuse arteritis. The second patient was more typical, with clinical symptoms developing 12 years after radiationtherapy for an oligodendroglioma. Occlusion of a proximal vessel that had been included in the radiation port ...
Two patients who developed large intracranial vessel occlusion after standard radiationtherapy for brain tumor are described. This form of vascular occlusion is usually seen in patients who have previously been treated by radiotherapy for intracranial tumor who then develop a relatively acute change in neurologic status. Histology of the lesion mimics accelerated focal arteriosclerosis. The clinical and radiographic manifestations of one case were highly atypical. The vasculopathy became evident shortly after termination of radiationtherapy for a fourth ventricular ependymoma, and the angiographic picture stimulated a diffuse arteritis. The second patient was more typical, with clinical symptoms developing 12 years after radiationtherapy for an oligodendroglioma. Occlusion of a proximal vessel that had been included in the radiation port ...
During the past 10 years, five infants with Kasabach-Merritt syndrome (K-M) receiving radiationtherapy were reported. We investigated whether radiationtherapy for K-M was useful and what the unfavorable factors of K-M were. During the past 10 years, we have treated five infants with K-M. The syndrome occurred at ages ranging from birth to 4 months. The incidence of female to male ratio was 3:2. Among 5 cases, the site of hemangioma was as follows; shoulder, anterior chest wall, lower abdominal wall, face and neck and inguinal site. All 5 cases received medication to control the coagulopathy including prednisone and blood transfusion at first. Because the platelet count and the bleeding tendency did not improve in any case, these cases received radiationtherapy. Total dose ranged from 5 to 10 Gy and fraction-size ranged from 0.5 to 1.75 Gy. Irradiation session ...
Two cases of primary Ewing's sarcoma of the rib are reported, in which radiationtherapy was quite effective. Case 1 was an 18-year-old female who had had an operation and radiationtherapy for Ewing's sarcoma of the left 7th rib. She was referred to our hospital after a recurrent tumor was found. Radiationtherapy (tumor dose 46.2 Gy) and chemotherapy were given. The tumor disappeared and there has been no relapse for 1 year and 3 months after the treatment. Case 2 was a 2-year-old-infant. Radiationtherapy (tumor dose 74 Gy) was given for primary Ewing's sarcoma of the left 6th rib. The tumor became small and was successfully removed at operation. There has been no relapse or distant metastasis for 8 months following the operation. We emphasize the importance of multidisciplinary treatment in case 1 and the usefulness ...
Purpose: The occurrence of extraosseous Ewing's sarcoma (ES) in deep soft tissues has been well described, but cases in which this tumor occurs in a primary cutaneous or subcutaneous site have rarely been reported. The superficial variant may be less aggressive than are the more common bony and deep soft tissue counterparts with an apparently favorable outcome. A retrospective review of patients with cutaneous or subcutaneous ES was conducted to analyze outcome and patterns of failure. Methods and Materials: Between July 1985 and March 1997, 14 patients with cutaneous or subcutaneous ES were treated at St. Jude Children's Research Hospital. The median age at presentation was 16 years (range 7-21 years). Anatomic locations included trunk and pelvis (7), upper or lower extremity (4), and head and neck (3). The median size of the lesion was 3 cm (range, 1-12 cm). Thirteen had definitive surgical resections, and one had biopsy of the mass at the time of referral. They were enrolled on ...
Little clinical evidence has been provided to show the minimization of radiation resistance of tumors using high linear energy transfer radiation. We therefore investigated the radiobiological and molecular pathological aspects of carbon beam therapy. A total of 27 patients with squamous cell carcinoma (SCC) of the cervix were treated using a carbon beam and 50 control patients with SCC of the cervix using a photon beam. The expression of Ki-67, p53, and p27 proteins before radiotherapy and 5 and 15 days after therapy initiation were investigated using immunohistochemistry. Similar changes were observed in Ki-67 labeling index (LI) and p53 LI during carbon and photon beam therapies. However, for carbon beam therapy, the mean p27 LI significantly decreased from 25.2% before treatment to 18.6% on the 5th day after treatment initiation, followed by a significant ...
The book is divided into two approximately equal parts. The first four chapters are relatively lengthy and cover the basic principles of radiation biology, carcinogenesis and therapy, along with a brief introduction to radiological physics to orient the reader without background in this specialized related discipline. The remainder consists of twenty-four relatively brief chapters, each covering the radiation biology of a specific organ, tissue, or systems tissues, with emphasis on the tumorigenic and tumoricidal action of ionizing radiations.
External radiation dose exceeded 5,000 rad in three cases, and intravaginal radiation dose was 5,000 rad in one case. Radiation damage including perforation was seen in the end of ileus in one case, in the sigmoid and rectum in two cases, and in the end of ileus, sigmoid and rectum in the last case. Satisfactory results were obtained by the removal of the ileocecum in the case of the damage in the end of the ileus. However, only colostomy was performed for the damage in the sigmoid and rectum.
Background and Purpose: In an earlier phase II study, irradiation together with razoxane was shown to improve local control in recurrent rectal cancer. Therefore, the Austrian Society of Radiooncology (OeGRO) initiated a randomized controlled trial in 1992 to compare this combined treatment versus radiationtherapy alone. Patients and Methods: Between 1992 and 1999, 36 patients with localized recurrences of rectal cancer were randomized to receive radiotherapy without (group A) or with razoxane (group B). The prognostic variables of the two groups were similar except for a longer median latency period from initial surgery to local recurrence in group A. High-energy photons with daily fractions between 170 and 200 cGy were used. The median total radiation dose was 60 Gy in each group. The patients in group B received a median razoxane dose of 9.6 g (range, 5-12 g). Main outcome measures were local ...
The role of radiationtherapy in local tumor control and decreased incidence of pulmonary metastasis is reported in 271 patients who were entered into the Intergroup Ewing's Sarcoma Study with more than one year follow-up and on whom all radiotherapy records were reviewed. The majority of the patients were irradiated to the primary tumor with doses of 4500 to 6500 rad in five to six weeks in combination with systemic administration of three drugs (vincristine, actinomycin-D and cyclophosphamide) or four drugs (vincristine, actinomycin-D, cyclophosphamide and adriamycin). One of the groups of patients was treated with three drugs and bilateral pulmonary irradiation (1500 rad, uncorrected dose, in two weeks). Preliminary analysis shows an overall local primary tumor control of 89%. Patients with lesions in the pelvis had a local failure rate of 17% (9 of 52) and in the humerus 23% (7 of 31). Factors affecting local ...
This paper is a progress report on the role of radiationtherapy (RT) in local tumor control and the decreased incidence of pulmonary metastasis in 251 patients entered in the Intergroup Ewing's Sarcoma Study. All were followed for more that 1 year, and their RT records were reviewed. Doses to the primary tumor in the range of 4,500--6,500 rad were administered over approximately 5 to 6 weeks in combination with 4 drugs, i.e., vincristine (VCR), dactinomycin (DAC), cyclophosphamide (CY), and adriamycin, or only the first 3. One group of patients received the 3 drugs and bilateral pulmonary irradiation (approximately 1,500 rad in 2 wk). Preliminary analysis showed a local primary tumor control of approximately 90%. Patients with lesions in the pelvis and humerus had local failure rates of 13% (7 of 54) and 21.4% (6 of 28), respectively. The treatment groups differed significantly in the incidence of pulmonary metastasis. ...
... Except for isolated radiation accidents over the ensuing years, little practical experience has been gained in the treatment of thermal injuries ...
Purpose/Objective: The role of programmed cell death (apoptosis) as a cellular response to cancer therapy such as radiation or chemotherapy is the subject of much study, and manipulation of the apoptotic response in tumor cells may be valuable in the treatment of a variety of cancers. Both p53 dependent and independent apoptotic pathways have been identified; p53 is mutated in at least 50 % of human cancers and a majority of radiation resistant tumors contain p53 mutations. This study is designed to examine the induction of programmed cell death in a human colon carcinoma cell line that possesses two mutated p53 alleles. Ionizing radiation alone, or in combination with the chemotherapeutic drug 5-fluorouracil (5-FU), were used to elicit the apoptotic response. This study will focus on whether these treatments can induce a significant apoptotic response in cells that have mutated p53 ...
Forty cases of Ewing's sarcoma of various sites had attended the Department of Radiotherapy at the Wanless Hospital and the Miraj Medical Centre, attached to the Government Medical College, Miraj, Maharashtra, from January, 1970 through December, 1979. There were 28 male patients and 12 female patients in the series with a male to female ratio of 2.3:1. The youngest patient in the series was a female of 6 years of age with the tumour in the scapula and the oldest patient was a 32-year-old male with a lesion in the metacarpal bone. Sixty per cent of the cases were seen in the second decade. The average age of the patients was 13.5 years. The bones of the lower extremities were most commonly involved with the highest number (35 per cent) of the cases occurring in the femur. Involvement of the bones of the right side of the body was almost equal to that of the left side. Swelling over the site of the lesion and pain over the swelling were the most common complaints noted in all the cases. ...
For over 50 years, electron beams have been an important modality for providing an accurate dose of radiation to superficial cancers and disease and for limiting the dose to underlying normal tissues and structures. This review looks at many of the important contributions of physics and dosimetry to the development and utilization of electron beam therapy, including electron treatment machines, dose specification and calibration, dose measurement, electron transport calculations, treatment and treatment-planning tools, and clinical utilization, including special procedures. Also, future changes in the practice of electron therapy resulting from challenges to its utilization and from potential future technology are discussed. (review)
Electron beam therapy has often been used for radiationtherapy of carcinomas of the buccal mucosa, though side effects, including stomatitis and dermatitis, are known to exist. We experimented using the additional back scatter and transit with the phantom under a lead plate within the irradiation field, in order to better focus the dose on the target volume moreover, we fabricated a mouthpiece fitted with a lead plate shaped to the target volume, and with respect to the influence of the mouthpiece on stomatitis and dermatitis, obtained good clinical results. (author).
Electron beam therapy has often been used for radiationtherapy of carcinomas of the buccal mucosa, though side effects, including stomatitis and dermatitis, are known to exist. We experimented using the additional back scatter and transit with the phantom under a lead plate within the irradiation field, in order to better focus the dose on the target volume moreover, we fabricated a mouthpiece fitted with a lead plate shaped to the target volume, and with respect to the influence of the mouthpiece on stomatitis and dermatitis, obtained good clinical results. (author).
A previously healthy young man experienced several episodes of syncope while being treated with tenofovir, emtricitabine and nevirapine initiated during primary HIV-1 infection. Symptoms disappeared after discontinuation of antiretroviral therapy and we suggest that syncope may be a side effect to one of the three antiretroviral drugs that has not been described previously.
This document is the report of a task group of the RadiationTherapy Committee of the AAPM and has been prepared primarily to advise hospital physicists involved in external beam treatment of patients with pelvic malignancies who have high atomic number (Z) hip prostheses. The purpose of the report is to make the radiation oncology community aware of the problems arising from the presence of these devices in the radiation beam, to quantify the dose perturbations they cause, and, finally, to provide recommendations for treatment planning and delivery. Some of the data and recommendations are also applicable to patients having implanted high-Z prosthetic devices such as pins, humeral head replacements. The scientific understanding and methodology of clinical dosimetry for these situations is still incomplete. This report is intended to reflect the current state of scientific understanding and technical ...
BackgroundAn artemisinin-based combinationtherapy, artesunate (AS) plus sulphadoxine-pyrimethamine (SP), was compared to SP monotherapy to provide evidence of further treatment...Full Text Available
Oncolytic viruses (OVs) represent a relatively novel anti-cancer modality. Like other new cancer treatments, effective OV therapy will likely require combination with conventional treatments. In order...Full Text Available
Electron beam therapy applied to a lymph node metastasis from a squamous cell carcinoma was followed by the development of histologically and immunologically typical bullous pemphigoid, the lesions being initially strictly confined to the irradiation area. This observation suggests that the bullous pemphigoid antigen may be altered or unmasked by electron beam radiotherapy, leading subsequently to the production of autoantibodies. The disease in this case effectively responded to the administration of tetracycline and niacinamide, a therapeutic regimen described recently.
Delayed cerebral necroses after irradiation are to be divided into hemispheric and midline lesions, as they differ from each other in several aspects. Apart from the symptoms, they are differing in the duration of latency, in the course and prognosis, and also with regard to morphology. Though there is no doubt that radiation tolerance of cerebral midline structures is relatively limited, on biological grounds, evidence of a difference between the tolerated doses could not be given from the existent inhomogeneous radiation data, with the help of the NSD-concept. Radiation planning for the region of the head, nevertheless, carefully should avoid in every case to involve the structures of the cerebral midline.
AbstractThe optimal definition of the size, shape and location of gross tumour volume is one of the most important steps in the planning of radiationtherapy, and necessitates a proper...Full Text Available
Microplanar beam radiationtherapy has been proposed to treat brain tumors by using a series of rapid exposures to an array of parallel x-ray beams, each beam having uniform microscopic thickness and...Full Text Available
... 46 DOUGLAS BOCCUZZI, MS, DABR: There are some electromagnetic fields in the room, not strong. You can ... 5 weeks or is she feeling any side effects? 00:43:33 SUSAN Y. KIM, MD: She ...
IntroductionIrradiation of normal, non-malignant bone during cancer therapy can lead to atrophy and increased risk of fracture at several skeletal sites, particularly...Full Text Available
SummaryRadiotherapy is used commonly in the treatment of gynecologic malignancies. Many patients experience emotional distress prior to the initiation of radiotherapy, during...Full Text Available
Voxel-based prescriptions of deliberately non-uniform dose distributions based on molecular imaging, so-called dose painting or theragnostic radiationtherapy, require specification of a transformation...Full Text Available
Patients experiencing several cancers can be a challenge, as optimal treatment options for the different cancers might interfere with each other. In this case report, we present a woman diagnosed with...Full Text Available
Purpose:To investigate the clinical usage of dose verification of Helical Tomotherapy plans by using 2D-array ion chambers, and to develop an efficient way to validate the dose delivered...Full Text Available
BackgroundTo compare the differences in dose-volume data among coplanar intensity modulated radiotherapy (IMRT), noncoplanar IMRT, and helical tomotherapy (HT) among patients with...Full Text Available
- flushing Chemotherapy - what to ask your doctor Dry Mouth Oral mucositis Peripherally inserted central catheter Radiationtherapy - what to ask your doctor Safe drinking during...
Purpose: Reverse helical cone-beam computed tomography (CBCT) is a scanning configuration for potential applications in image-guided radiationtherapy in which an accurate anatomic image...Full Text Available
Purpose: A retrospective analysis was undertaken to determine the indications for, the efficacy of, and the long-term complications of two courses of total skin electron beam therapy for mycosis fungoides. Methods and Materials: A retrospective analysis of 15 patients with the pathologic diagnosis of mycosis fungoides treated in the Department of Radiation Oncology at Stanford University Medical Center between 1968 and 1990 was performed. All patients received two courses of high-dose electron beam therapy to the skin. The mean dose for the total skin treatment for the first course was 32.6 Gy and 23.4 Gy for the second course of treatment. Results: Following the first course of total skin electron beam therapy, 11 of 15 had a complete response, with a mean duration of 11.6 months. All patients received adjuvant therapies between the first and second courses of high-dose total skin ...
This book examines the applications of Monte Carlo (MC) calculations in therapeutic nuclear medicine, from basic principles to computer implementations of software packages and their applications in radiation dosimetry and treatment planning. It is written for nuclear medicine physicists and physicians as well as radiation oncologists, and can serve as a supplementary text for medical imaging, radiation dosimetry and nuclear engineering graduate courses in science, medical and engineering faculties. With chapters is written by recognised authorities in that particular field, the book covers the entire range of MC applications in therapeutic medical and health physics, from its use in imaging prior to therapy to dose distribution modelling targeted radiotherapy. The contributions discuss the fundamental concepts of radiation dosimetry, radiobiological aspects of targeted radionuclide ...
Authors developed a C-arm type radiosurgery system of the linear accelerator suitable for stereotactic radiationtherapy and a software for arranging 3-dimensional therapy in the system. In this system, the gantry far conical irradiation of 4 MV (0.6-3 Gy/min) and 6 MV (0.9-4.5 Gy/min) X ray or electron beam for the therapy was connected to a newly designed C-arm and was made capable of rotating around either of the axes crossing vertically. With this system, it became unnecessary to move the bed table of the patient for getting suitable distribution of radiation dose. The local accuracy which was measured by the CCD videocamera on the gantry, was within 0.5 mm from the radiation center. The system made it possible to shorten the irradiation time and to improve the local accuracy of irradiating site. The clinical trial was begun from June, 1996. (K.H.)
It may result in acute radiation syndrome after body is exposed to ionizing radiation. The one of long-term effects of irradiation injury is leukemia. The bone marrow cells (BMC) transplantation including stem cells is the only effective therapy for acute radiation syndrome patients. Recently, with the advancement of stem cell research that the stem cells have multipotential and can convert each other, it may supply the new stem source for the irradiation injury patients. At the same time with the further research of radioprotective reagents, the hematopoietic stem cells proliferation after irradiation injury is promoted
Using an adenoviral system as a delivery mediator of therapeutic gene, we investigated the therapeutic effects of the use of combined MDR1 shRNA and human NIS (hNIS)...Full Text Available
BackgroundSeveral studies have demonstrated the efficacy of artemisinin-combinationtherapy (ACT) across malaria zones of the world. Fixed dose ACT with shorter courses and fewer...Full Text Available
Purpose: To evaluate the results of radiotherapy in cholangiocarcinoma patients managed with various combinations of chemotherapy and surgical resection with selective liver transplantation. Methods and Materials: From January 1990 to December 1995, 61 patients with histologically confirmed biliary duct adenocarcinoma were seen in the Radiation Oncology Department of the University of Pittsburgh. Median follow-up was 22 months (1 to 91 months). The extent of surgery was complete resection in 23 patients (including 17 with orthotopic liver transplant), partial resection in 4, and biopsy in 34. All patients had radiotherapy; median dose was 49.5 Gy. Thirty patients received chemotherapy: 5-fluorouracil (5-FU)-leucovorin with interferon alpha (IFN#alpha#) in 27, and taxol in 3. Results: The median survival was 20 months (95% CI 15-25 months). The 5-year actuarial survival was 23.8 #+-# 6.8%. The only significant variable in multivariate analysis ...
The use of absorbable polyglactin 910 mesh (Vicryl) is described in a case of Ewing's sarcoma of the pelvis. An operation was performed to hold the small bowel and colon out of the pelvis for a temporary period during which radical radiotherapy was delivered. The mesh allowed the temporary displacement of bowel and obviated bowel radiation morbidity. (author).
Results are presented applying an enteral nutrition by means of probes with Cosilat in complex therapy of patients with radiotherapeutic late effects of the colon. This nutrition was prescribed with the intention to gave the colon a functional recovery and to guarantee optimal conditions for repair of radiation injuries. Good results were seen in 27 of 28 patients (96.7%), the situation of one patient (3.3%) continued without any change. Cosilat has a high nutritive value, good organoleptic qualities and is well digested without any complications. (author).
Forty-three patients with basal and squamous cell carcinomata arising on the pinna were treated radically using a 10 MeV electron beam. The technique and dosage are described and discussed. Primary cancer control with retention of the pinna was achieved in 34 patients. Salvage pinnectomy was performed in four patients for recurrence and one patient for radiation necrosis. Two patients with large primary tumours failed to resolve and died of their disease. The advantages for the patient of the policy of primary radical electron beam therapy are discussed.
The document represents a guide for the external decontamination of persons accidentally radio contaminated due to the use, production or transport of radioactive materials. The general conditions, from the medical point of view, to be kept in mind, in the event of accidental overexposures as decontamination treatment and the handling of samples are detailed throughout report. The external contamination without injury in skin or with wound its considered. The distribution of measures and responsibilities for the therapy of the irradiated patients with radioactive materials are enumerated. The preparations of decontaminate solutions are detailed in this work. Moreover, forms for the reception, physical evaluation of the patient and external contamination are presented. (author)
Abstract Satellite measurements and numerical forecast model reanalysis data are used to compute an updated estimate of the cloud radiative effect on the global multi-annual mean radiative energy budget of the atmosphere and surface. The cloud radiative cooling effect through reflection of short wave radiation dominates over the long wave heating effect, resulting in a net cooling of the climate system of - 21 Wm-2. The short wave radiative effect of cloud is primarily manifest as a reduction in the solar radiation absorbed at the surface of - 53 Wm-2. Clouds impact long wave radiation by heating the moist tropical atmosphere (up to around 40 Wm-2 for global annual means) while enhancing the radiative cooling of the atmosphere over other regions, in particular higher latitudes and sub-trop...
The book examines current experimental and clinical knowledge concerning the biological and biophysical effects of electromagnetic radiation, particularly that in the microwave range. The biophysical bases of the interaction of electromagnetic radiation with matter are reviewed with emphasis on biological systems, and the effects of radiation on critical biological systems, including the nervous, reproductive, visual and blood-forming systems are compared. Data concerning the lethal effects of nonionizing radiation is presented and characteristics of the effects of electromagnetic radiation on the whole mammalian organisms are examined. Various reactions of the neuroendocrine system to electromagnetic radiation are described, with particular attention given to the adrenal system, and the combined effects of ionizing and microwave ...
A thermoluminescence (TL) sheet and its spatial readout system for in vivo measurement of spatial dose distribution around sources has been newly developed for intracavitary high dose-rate radiationtherapy. The TL sheet (40 cm x 50 cm x 200 {mu}m), which is composed of teflon mixed with BaSO{sub 4} (Eu doped) powder, has a linear response with a very wide dynamic range from at least 0.002 cGy to 5000 cGy for {sup 60}Co sources. Phantom test of the TL sheet readout system demonstrated that absorbed dose with TL sheet and that with ionization chamber as standard dosimeter agreed well. For clinical application, TL sheet was attached on an applicator of intracavitary radiationtherapy for rectal cancer. After irradiation with high dose-rate {sup 60}Co sources, the in vivo dose distribution on the surface of the rectum was determined. The TL sheet was suggested to provide a convenient means of measuring the ...
We report a patient who developed occlusion of the intracranial major arteries induced by radiationtherapy for craniopharyngioma. The patient, a 9-year-old boy, presented with deterioration of vision, nausea and vomiting. He underwent a right ventriculo-peritoneal shunt operation, and the tumor was partially removed. Postoperatively, he received focal radiationtherapy with total of 60 Gy. Preoperative cerebral angiography, cerebral vessels had no sigh of occlusive lesion or stenosis. One year after irradiation, he started to have repeated cerebral ischemic attacks. But no regrowth of the tumor was detected on CT scans. Two years and 8 months after irradiation, he suddenly had right hemiparesis. Cerebral angiography revealed severe stenosis of the right anterior cerebral artery (precommunicating segment), middle cerebral artery (horizontal portion) and terminal portion of the right carotid artery. Left ...
We report a patient who developed occlusion of the intracranial major arteries induced by radiationtherapy for craniopharyngioma. The patient, a 9-year-old boy, presented with deterioration of vision, nausea and vomiting. He underwent a right ventriculo-peritoneal shunt operation, and the tumor was partially removed. Postoperatively, he received focal radiationtherapy with total of 60 Gy. Preoperative cerebral angiography, cerebral vessels had no sigh of occlusive lesion or stenosis. One year after irradiation, he started to have repeated cerebral ischemic attacks. But no regrowth of the tumor was detected on CT scans. Two years and 8 months after irradiation, he suddenly had right hemiparesis. Cerebral angiography revealed severe stenosis of the right anterior cerebral artery (precommunicating segment), middle cerebral artery (horizontal portion) and terminal portion of the right carotid artery. Left ...
The work scope of 'Biological Research for the Radiation Protection' had contained the research about ornithine decarboxylase and its controlling proteins, thioredoxin, peroxiredoxin, S-adenosymethionine decarboxylase, and glutamate decarboxylase 67KD effect on the cell death triggered ionizing radiation and H_2O_2(toxic agents). In this study, to elucidate the role of these proteins in the ionizing radiation (or H_2O_2)-induced apoptotic cell death, we utilized sensesed (or antisensed) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation and H_2O_2(or paraquat). We also investigated whether genisteine(or thiamine) may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation (may enhance the preventing effect ...
The technical complexity of intraoperative radiotherapy (IORT) requires modification of the standard physical and dosimetric methods used in external electron beam therapy. At the National Cancer Institute, a number of technical innovations have been integrated into ongoing clinical studies of IORT. These include: (1) an electron beam applicator system that is significantly different from other IORT systems and includes customized squircle applicators; (2) peripheral dose shields; (3) a modified surgical table replacing the standard radiation treatment couch; and (4) routine use of multiple IORT fields that necessitates field matching. The IORT applicator system and related devices and techniques are dosimetrically characterized in detail both for use in the IORT program and in order to illustrate many useful facets of electron dosimetry.
Purpose: The aim of this study was to assess interinstitutional variations in planning for stereotactic body radiationtherapy (SBRT) for lung cancer before the start of the Japan Clinical Oncology Group (JCOG) 0403 trial.Methods and Materials: Eleven institutions created virtual plans for four cases of solitary lung cancer. The created plans should satisfy the target definitions and the dose constraints for the JCOG 0403 protocol.Results: FOCUS/XiO (CMS) was used in six institutions, Eclipse (Varian) in 3, Cadplan (Varian) in one, and Pinnacle3 (Philips/ADAC) in one. Dose calculation algorithms of Clarkson with effective path length correction and superposition were used in FOCUS/XiO; pencil beam convolution with Batho power law correction was used in Eclipse and Cadplan; and collapsed co...
Purpose: In this paper, we present an alternative to the originally proposed technique for the delivery of spatially fractionated radiationtherapy (GRID) using multi-leaf collimator (MLC) shaped fields. We employ the MLC to deliver various pattern GRID treatments to large solid tumors and dosimetrically characterize the GRID fields. Methods and materials: The GRID fields were created with different open to blocked area ratios and with variable separation between the openings using a MLC. GRID designs were introduced into the Pinnacle3 treatment planning system, and the dose was calculated in a water phantom. Ionization chamber and film measurements using both Kodak EDR2 and Gafchromic EBT film were performed in a SolidWater phantom to determine the relative output of each GRID design as w...
The effect of adriamycin in combination with radiation on the skin reactions of mouse feet has been examined under a variety of experimental conditions including: (a) hyperthermic treatment of the foot immediately following adriamycin administration, with the former given either just before or just after x irradiation, and (b) fractionated treatments of drug and radiation in a variety of sequences over an 18-day period. In the case of the most severe hyperthermic treatment, no increased radiation reactions were observed in the presence of adriamycin. However, in the case of the less severe hyperthermic treatment a small but significant increase in skin reactions was observed. In the study of fractionated drug and radiation treatments, an enhancement of reaction in those animals receiving combined modality treatment over those receiving ...
Patients with haemarthros of the knee were examined by MRI and arthroscopy to identify the bleeding source and to determine surgical or conservative therapy. A prospective study was performed on 120 patients who underwent MRI and arthroscopy, point lesions and bleeding sources were documented separately on a standardised form. Arthroscopy demonstrated a ruptured anterior cruciate ligament in 86%, meniscal tears in 55%, disruption of collateral ligaments in 17%, osteochondral lesions in 5% and tears of capsule or plicae in 13%. Disruption of cruciate ligaments caused haemorrhage in all but three cases. In contrast, only meniscal tears located very adjacent to the meniscal basement had bled. Those types of osteochondral lesions caused haemorrhage characterised on MRI by destruction of the subchondral plate and overlying cartilage. Severe lesions of the knee were diagnosed by MRI in 71% to 100%, slight lesions in 13% to 40% of the cases. Single, ...
Purpose: The aim of this study was to create, perfect and test a hyperthermia balloon catheter for local treatment of cholangiocarcinoma. The device should induce hyperthermia in tumor tissue by acting locally in the bile duct lumen in contact with the tumor-infiltrated duct wall. In addition, it should exert tissue compression to cause an appreciable reduction in tumor microvasculature flow, thus improving thermal performance. Methods: According to the design specifications, the working temperature range should allow the device to be used for hyperthermia therapy either in combination with radiation and/or chemotherapy(radio/chemo-sensitizing effect at 42-45 deg. C) or alone (induction of coagulation necrosis above 65 deg. C). The balloon serves as an anchoring system during treatment and as a functional element to induce tissue compression. In vitro mechanical evaluation of the pressure/volume relationship, with the ...
Background and purpose: We evaluate the feasibility of concomitant and adjuvant docetaxel combined with three-dimensional conformal radiotherapy (3D-CRT) and androgen deprivation in high-risk prostate carcinomas. Methods: Fifty men with high-risk localized prostate cancer (16), locally advanced (28) or very high-risk prostate cancer (6) were included. Seventy Gy were delivered on prostate and seminal vesicles in 35 fractions, concurrently with weekly docetaxel (20 mg/m"2). Three weeks after the completion of 3D-CRT, docetaxel was given for 3 cycles (60 mg/m"2), every 3 weeks. Patients had to receive LHRH agonist during 3 years. Results: The intent to treat analysis shows that four patients out of 15 stopped prematurely the chemotherapy due to grade 3-4 acute toxicity. In the per protocol analysis, 46 patients completed a full-dose chemoradiation regimen representing 413 cycles: five patients experienced a grade 3 toxicity, and 15 patients experienced a grade 2 ...
Combined treatment of 131 patients aged 3-16 with local form of Ewing's sarcoma is carried out. Survival rate per year was studied in patients without diagnosed metastases depending on chemiotherapy method. It is stated that improved results of treatment of children with Ewing's sarcoma may be achieved by combining radiotherapy with long-term systemic polychemotherapy. The most efficient and expedient method of radiotherapy of long bone sarcoma in children is dialy three-field irradiation with 2 Gy at SFD to the tumor 60 Gy, and adjacent tissues - 40 Gy.
Twenty-four high-risk Ewing's sarcoma patients were treated on an intensive combined modality protocol including low-dose fractionated total body irradiaiton (TBI) and autologous bone marrow infusion (ABMI). Twenty patients (83%) achieved a complete clinical response to the primary and/or metastatic sites following induction therapy. The median disease-free interval was 18 months, and nine patients remain disease-free with a follow-up of 22 to 72 months. Local failure as a manifestation of initial relapse occurred in only three patients (15%), each having synchronous distant failure. Eight patients failed initially with only distant metastases, usually within 1-2 years following a complete clinical response. Two patterns of granulocyte recovery following consolidative therapy (including TBI and ABMI) were recognized. The time to platelet recovery was different for the groups with early and late granulocyte recovery. ...
Epiphyseal plates of growing bones are sensitive to ionizing radiation and this poses problems for the paediatric radiotherapist. In this case report we describe a child in whom electron beam therapy to the groin delivered only low dose radiation to the proximal hip epiphyses - 130 cGy fractionated over 5 weeks - but who suffered late maldevelopment. We explore the success of various radiotherapy techniques in minimizing the dose to the hip epiphyses in four other children. The appropriate positioning of the limb, the choice of treatment modality and, where possible, individual shielding blocks are considered and their effect on the dose to the hip estimated. Absorbed doses of radiation delivered to the midpoint of the proximal femoral epiphyses have been retrospectively determined. (author).
A 38 year old male dentist developed an oligodendroglioma of the left medial temporal lobe and parasellar region 12 years after radiotherapy with 6600 rads for acromegaly. The 30 cases of radiation-induced gliomas reported in the English literature are reviewed and analysed. The criteria for defining radiation-induced tumours of the central nervous system are proposed as follows: the tumour has a long quiescent ''latency period'', a location in the previously irradiated field, a verified histological difference from a primary condition, and does not arise from a primary condition associated with a genetic syndrome such as neurofibromatosis or tuberous sclerosis. The reported case fulfilled these criteria but appears to be the only reported radiation-induced oligodendroglioma.
The long-term survival of certain patients after treatment with radiation or chemotherapeutic agents has allowed the realization that agents that effectively control cancer in the human subject may also possess an oncogenic potential, resulting in secondary malignancies in a significant proportion of surviving patients. A quantitative assessment of the oncogenic effects of these agents at a cellular level is important, as is information on conditions and agents that may effectively alter the development of the neoplastic state. Cell culture systems where the neoplastic transformation of cells can be scored after exposure to carcinogens offer powerful tools for evaluating the oncogenic potential of radiation and chemotherapeutic agents.
The effects of various antioxidants and antioxidant concentrations on the radiation and thermal stability of EPDM and XLPE polymers used for insulation of electric cable in nuclear power plants were measured. The objective was to determine if particular antioxidants could be identified as being especially effective for stabilization against radiation aging and combined thermal and radiation aging. Elongation to rupture was used as the measure of stability. Materials were irradiated to doses up to 2 MGy (200 Mrad) at a dose rate of 200 to 300 Gy/h in the Cobalt-60 Gamma Irradiation Facility at the University of Virginia. All of the antioxidants tested, which were known to provide excellent thermal stability, also provided good stability for radiation aging and combined thermal/radiation aging, although small differences between antioxidants ...
A set of eight questions was put to advanced nuclear medicine physicians-in-training participating in a continuing assessment exercise in practical therapeutic nuclear oncology. Using the particular example of {sup 131}I-MIBG treatment of neuroblastoma in children, the questions were directed to the rationale of therapy and the contribution of other forms of treatment to toxic effects. The best answer to the questions are reproduced together with an introduction by the examiner, Dr. H. Turner. tabs.
The reconstruction of coronal and Sagittal Image of Brain C. T. is helpful to diagnosis of Brain. Three Dimensional Reconstruction software package allows to display three dimensional Image clerived from a series of Horizontal, Sagittal and Coronal Brain C. T. images. It useful in determine approach of operation, to define portals of deep radiationtherapy.
PurposeUsing a retrospective analysis of treatment plans submitted from multiple institutions accruing patients to the RTOG #0236 non-small cell SBRT protocol, this...Full Text Available
The application of photopolymerisation (UV) and electron beams (EB) technologies in radiation rapid cure (PRC) processing is discussed. The chemistry associated with such reactions and the mechanisms of the processes are treated. The occurrence of concurrent grafting to substrate with radiation curing of films is shown to be an advantage in enhancing the properties of certain finished products. The parameters influencing the optimum grafting yield in such PRC processes are discussed. In many applications, the chemistry of such processes combined with the machine, specially for EB is shown. (author).
Thermal absorption with its combined thermal and mechanical loads in a solar receiver does depend significantly on the distribution of incident solar radiation. For a cavity receiver with paraboloid collectar a method is derived which enables the calculation of solar radiation distribution on the areas inside the receiver. The theoretical bases are presented first, and a subsequent example shows the influence of the most important geometric parameters on the distribution of solar radiation.
This paper describes the research and development activities in three areas of radiation processing, namely: food irradiation, medical product sterilization and wood plastic combination. Plans and efforts exerted to acquire a larger gamma source to augment our present 5,000 curie source are discussed. Cost estimates for a radiation facility are presented on the basis of the market potential of food irradiation and medical product sterilization. Existing local industries that can benefit from the adaptation of irradiation technology in their processing requirements are described.
Purpose: To evaluate the outcomes of patients with Ewing's sarcoma family of tumors (ESFT) treated with modern radiotherapy techniques with MRI along with optimal chemotherapy. Methods and Materials: The records of all 60 patients with ESFT who received radiation to the primary site between 1990 and 2004 were reviewed. All patients received chemotherapy, including vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide. Radiation was used as the sole modality for local control in 31 patients and was given either before (n = 3) or after surgical resection (n = 26) in the remainder. All patients had MRI and CT scan-based treatment planning, and 43% received intensity-modulated radiationtherapy. Radiation doses ranged from 30 Gy to 60 Gy (median, 51 Gy), and 35% received hyperfractionated radiotherapy. Results: Median age was 16 years (range, 2-40 years). Because of ...
Clinical studies have proved the effectiveness of local ablading methods in pations with non-resectable liver metastases of a colorectal carcinoma. RF ablation and LITT are a potentially curative therapy option and an alternative to systemic chemotherapy; the latter is carried out primarily for reducing tumour size with the goal of secondary resectability. The number of R0-sesectable metastases can be enhanced by a combinedtherapy of surgery and local ablading methods, e.g. by preoperative, intraoperative or postoperative ablasion of further non-resectable tumours during surgery. Systemic chemotherapy combined with surgery as an adjuvant method is not recommended unless in cases of non-abladable tumour recidivation. Currently, systemic chemotherapy is used as a neo-adjuvant therapy for tumour size reduction with the goal of secondary resectability or, in case of inoperability, ...
... or she will start intensive rehabilitation. This includes physical therapy and occupational therapy. Physical and occupational therapies aim at strengthening the remaining ...
In this study, a miniature fiber-optic radiation detector has been developed using a water-equivalent organic scintillator for electron beam therapy dosimetry. Usually, two kinds of light signals such as fluorescent and Cherenkov lights are generated in a fiber-optic radiation detector when a high-energy electron beam is irradiated. The fluorescent light signal is produced in the scintillator and is transmitted through a plastic optical fiber to a remote light-measuring device such as a PMT or a photodiode. The Cherenkov light could be also produced in the plastic optical fiber itself and be detected by a light-measuring device. Therefore, it could cause problems or limit the accuracy of the detection of a fluorescent light signal that is proportional to dose. The objectives of this study are to measure, characterize and eliminate Cherenkov light generated in a plastic optical fiber used as a component of a fiber-optic ...
Megavoltage photon intensity-modulated radiationtherapy (IMRT) is typically used in the treatment of prostate cancer at our institution. Approximately 1% to 2% of patients with prostate cancer have hip prostheses. The presence of the prosthesis usually complicates the planning process because of dose perturbation around the prosthesis, radiation attenuation through the prosthesis, and the introduction of computed tomography artifacts in the planning volume. In addition, hip prostheses are typically made of materials of high atomic number, which add uncertainty to the dosimetry of the prostate and critical organs in the planning volume. When the prosthesis is bilateral, treatment planning is further complicated because only a limited number of beam angles can be used to avoid the prostheses. In this case study, we will report the observed advantages of using noncoplanar beams in the delivery of IMRT to a prostate cancer ...
Total 125 patients with primary and metastatic Ewing's sarcoma were treated in various ways between 1963 to 1977. Patients were divided into 3 groups according to the treatment methods. Group 1 was nonprotocol patients with or without chemotherapy. Total 58 patients were entered. Group 1 was divided into 2 subgroups. 33 patients were treated locally without chemotherapy and 25 patients were treated with local therapy and nonprotocol chemotherapy. Group 2 was treated with local therapy and plus T-2 regimen multiagent chemotherapy. 29 patients were entered. Group 3 was treated with local therapy and T-6 regimen multiagent chemotherapy. 38 patients were entered. Local treatments for primary tumor were surgery and/or radiationtherapy. Radiation dose ranged between 2,000 and 8,000 rad. Patients with pulmonary metastases received bilateral pulmonary RT. Local ...
In this paper the measurements of radon-222 concentration in the air of Kowary Radon Inhalatorium in the vicinity of Jelenia Gora, Lower Silesia, Poland, performed by Radiation Protection and Radiobiology Department of National Institute of Hygiene in Warsaw, have been presented. For the measurements the integration method with the application of charcoal canisters have been used. The radon concentration was found within the very broad ranges from about 4 to 420 kBq m"-"3 depending of the season of the year. Basing on the radon concentration measurements during the inhalation therapy session and taking into account the equilibrium factor of 0.8 the doses to the bronchi of the patients in range from 1.2 to about 204 mSv (0.12-20.4 rem) have been assessed. The majority of patients (ca. 76%) received the doses between 115 and 204 mSv. (author)
The atomic explosions in Hiroshima and Nagasaki made the name radiation itself become a nightmare. Notwithstanding this, radiation continued to serve the mankind specially in diagnosis of several human diseases and in the treatment of intractable malignancies. With their latest research tools biologists have now shown a significant shift in the earlier paradigm; even the concept that radiation initiates cancer appears to be no longer tenable. On the contrary, selective radiation doses inhibit growth of cancer cells and radiation in combination with many chemotherapeutic drugs, radiosensitizing chemicals and/or hyperthermia, is emerging as a new modality for cancer treatment which offers high therapeutic advantages. In addition, the deleterious effects of radiation can now be strategically counter poised by the use of many drugs and ...
Purpose: Patients with mycosis fungoides [cutaneous T-cell lymphoma (CTCL)] may benefit from adjuvant therapy after completing total skin electron beam therapy (TSEBT). We report the results for (T1(T2)) CTCL patients treated with adjuvant oral psoralen plus ultraviolet light (PUVA) with respect to overall survival (OS), disease-free survival (DFS), salvage of recurrence, and toxicity. Methods and Materials: Between 1974 and 1993, TSEBT was administered to a total of 213 patients with CTCL. Records were reviewed retrospectively, and a total of 114 patients were identified as having T1 or T2 disease. Radiotherapy was provided via a 6-MeV linac to a total of 36 Gy, 1 Gy/day, 4 days/week, for 9 weeks. Beginning in 1988, patients were offered adjuvant PUVA within 2 months of completing TSEBT. This was started at 0.5-2 J/m"2, 1-2 treatments/week, with a taper over 3-6 months. Therapy then continued once per month. There were 39 ...
Radiation damage of the final optical components in an Inertial Confinement Fusion (ICF) reactor is a crucial issue for development of a laser-fusion reactor. To some extent, this problem will be encountered in the National Ignition Facility (NIF), but there, the integrated radiation dose will be considerably less than that encountered in a future reactor. This extremely harsh radiation environment necessitates shielding the ICF optics from direct neutron and x-ray bombardment. Several approaches have been suggested, such as the use of grazing incidence metal mirrors or fused silica wedge deflectors. While metal mirrors can withstand a larger radiation dose, their focusing qualities pose problems. Therefore wedge deflectors, originally suggested by Lawrence Livermore National Laboratory (LLNL) staff, represent a promising alternative. Radiation hardening of the fused silica ...
Gel dosimetry is a new dosimetry method applied in radiationtherapy. Gel dosimeters consist of a radiation sensitive gel, which can integrate absorbed doses from several radiation sources or beams. The dose to the gel can be evaluated by magnetic resonance imaging (MRI), a procedure that is the focus of the present thesis. A robust tool for the evaluation of the nonuniformity in MRI has been developed, the Deviation Image method. Unlike previously presented methods, the Deviation Image method includes all nonuniformity variations across a phantom surface and is insensitive to stochastic noise. Methods for the estimation of stochastic noise were analyzed in terms of sensitivity to nonuniformities. A method that averages the stochastic noise level over five regions over the phantom surface, and a method that assesses the stochastic noise level from the background, were found to be the methods of choice. ...
As part of a combined study of the responses of the mouse adrenal gland and kidney to X-irradiation, the weight of adrenal glands, the relative volumes of the cortex and medulla and the aldosterone output were measured at predetermined times after irradiation of the left organs only.
In view of poor local control rates obtained with standard treatment, intraoperative radiation (IORT) using electrons was combined with external beam irradiation and surgical resection, with or without...Full Text Available
A prospective pilot trial was performed in 20 patients randomised to receive either {sup 131}I-Lipiodol therapy alone (n=10) or {sup 131}I-Lipiodol combined with a short low-dose cisplatin infusion (n=10), the aim being to evaluate the possible positive influence of a radiosensitiser on toxicity and tumour response. An activity of 1,354-2,128 MBq (mean 1,824 MBq) [36.6-57.5 mCi (mean 49.3 mCi)] {sup 131}I-labelled Lipiodol was administered by selective instillation in the hepatic artery. Cisplatin was given in a dose of 30 mg/m{sup 2} at day -1 and day +6 (day 0: {sup 131}I-Lipiodol). The primary endpoint of this trial was toxicity of therapy; points of secondary interest were tumour response and survival at 6 months. With the use of cisplatin we found a higher percentage of stable or diminished tumour size (90%, vs 40% without). A benefit in group survival at 6 months was not evident. Low-grade stomatitis in one patient ...
Over a 5-year period (1976-1980) 499 patients with non-seminomatous testicular germ cell tumours were included in the Danish Testicular Carcinoma Study (DATECA). The 3-year crude survival for patients in clinical stages I, II and III was 91, 77 and 45 per cent, respectively. In stage I the relapse-free survival for patients given radiationcombined with bleomycin and vincristine was significantly higher than that for patients given radiation alone. No difference in the crude survival for patients given radiationcombined with bleomycin and vincristine was significantly higher than that for patients given radiation alone. No difference in the crude survival was observed. For stage II patients maintenance chemotherapy following radiationcombined with bleomycin and vincristine did not improve relapse-free or crude ...
Over a 5-year period (1976-1980) 499 patients with non-seminomatous testicular germ cell tumours were included in the Danish Testicular Carcinoma Study (DATECA). The 3-year crude survival for patients in clinical stages I, II and III was 91, 77 and 45 per cent, respectively. In stage I the relapse-free survival for patients given radiationcombined with bleomycin and vincristine was significantly higher than that for patients given radiation alone. No difference in the crude survival for patients given radiationcombined with bleomycin and vincristine was significantly higher than that for patients given radiation alone. No difference in the crude survival was observed. For stage II patients maintenance chemotherapy following radiationcombined with bleomycin and vincristine did not improve relapse-free or crude ...
For the step-and-shoot intensity-modulated radiationtherapy (IMRT) technique, the combination of high dose rate, multiple beam segments and low dose per segment can lead to significant differences between the planned dose and the dose delivered to the patient. In this technique, a dose delivery inaccuracy known as the 'overshoot' effect is caused by the dose servo control system. This typically occurs in the first and last beam segments and causes an over- and underdose, respectively. Some dose positional error in the segment sequence is also possible there. Commercial ionization chambers (RK-type) and radiographic Kodak films were used for the measurements. The reported results were obtained using the Pinnacle{sup 3}-V6.2 treatment planning system and a Varian Clinac 21 EX linear accelerator equipped with a 120-leaf Millennium MLC. The dose inaccuracy measurements were based on the comparison of the dose ...
Therapeutic effect of p-aminobenzoic acid-N-xyloside Na (K-247) were studied. Eleven patients with a variety of solid tumors were treated with K-247 alone. K-247 was given orally 800 mg daily for 4 weeks. As for side effect of the drug, only mild gastritis was observed in a few patients. Partial response (over 25% reduction of tumor size) with a median duration of two months was observed in 3 patients. These cases were metastatic tumor of lung from the carcinoma of thyroid, metastatic tumors of lung from the carcinoma of kidney, and mediastinal tumor. In eight patients the response was classified as no change and in one patient there was progressive disease. Thus K-247 has some therapeutic activity in patients with solid tumor. Combinationtherapy of irradiation and administration of K-247 were also studied. In the twelve patients receiving the combinationtherapy, partial response was observed in 7 ...
Gantries in the proton/carbon cancer therapy machines represent the major cost and are of the largest size. This report explains a new way to the gantry design. The size and cost of the gantries are reduced and their use is simplified by using the fixed magnetic field. The ''new'' gantry is made of a very large momentum acceptance non-scaling Fixed Field Alternating Gradient (FFAG) quarter and half arc beam lines. The gantry is made of combined function magnets with a very strong focusing and small dispersion function. Additional magnets with a fast response are required to allow adjustments of the beam position for different energies at the beginning of the gantry. Additional strong focusing magnets following the gantry have also to be adjustable to provide required spot size and radial scanning above the patients. The fixed field combined function magnets could be made of small ...
Purpose: In this paper, we present an alternative to the originally proposed technique for the delivery of spatially fractionated radiationtherapy (GRID) using multi-leaf collimator (MLC) shaped fields. We employ the MLC to deliver various pattern GRID treatments to large solid tumors and dosimetrically characterize the GRID fields. Methods and materials: The GRID fields were created with different open to blocked area ratios and with variable separation between the openings using a MLC. GRID designs were introduced into the Pinnacle"3 treatment planning system, and the dose was calculated in a water phantom. Ionization chamber and film measurements using both Kodak EDR2 and Gafchromic EBT film were performed in a SolidWater phantom to determine the relative output of each GRID design as well as its spatial dosimetric characteristics. Results: Agreement within 5.0% was observed between the Pinnacle"3 predicted dose distributions and the ...
In the context of radiation protection for both workers and the population in general, natural sources of radiation, and in particular radon gas and its short-life decay products assume great importance. In particular, workers in thermal spas can easily be exposed to a level of radon radiation and its decay products comparable to those in uranium mines, though often these workers are unaware of the danger. The main source of radon in thermal baths is the thermal water itself, coming as it often does from deep springs, and this can produce high radon concentrations which are left in those areas in which therapy is carried out. Another factor which cannot be overlooked is the radioactive content of thermal mud, often matured for long periods by contact with thermal water. Thermal cures, though varying slightly from site to site, consist principally of mud cures, hydro-therapy and ...
The discussion focuses on the ways in which the 3 panelists in their lives and work embody fourth wave feminism, which combines politics, psychology, and spirituality in an overarching vision of change. Jane Fonda's emphasis on the importance of making narratives of gender a central organizer for personal and societal transformation, Hedda Bolgar's insistence that psychoanalysts recognize the complex dialectic between unconscious dynamics and sociocultural realities in order not to conflate conflicts rooted in social inequalities with individual issues, and Sue Shapiro's understanding of the ambiguous role of individual therapy in situations of historical and social trauma such as the tsunami in Indonesia are all examples of fourth wave feminism in practice. The unfinished business of the ...
Dyspnea is the most distressing symptom experienced by those suffering from advanced stages of chronic obstructive pulmonary disease (COPD). Activity-related dyspnea in COPD is multifactorial but is associated with increased central neural drive, impaired dynamic respiratory mechanics and abnormal respiratory muscle function. Each of these components can potentially be targeted for pharmacotherapy. Recent advances in the pharmacotherapy of COPD include the development of new long-acting bronchodilators which, when combined, provide sustained improvements in dyspnea. Additionally, novel applications of older therapies such as opiates, furosemide, helium-oxygen, and statins show early promise as dyspnea-relieving interventions in COPD. Effective pharmacological manipulation of the affective ...
Endothelial dysfunction and increased platelet aggregation may be involved in the pathogenesis of normal tissue radiation toxicity. This study assessed clopidogrel, an inhibitor of ADP-induced platelet aggregation, as a modulator of intestinal radiation injury (radiation enteropathy). Rat small intestine was exposed to 21 Gy X-radiation. Clopidogrel (20 mg/kg/day) or vehicle was administered from 2 days before to 10 days after irradiation. Structural radiation injury, neutrophil infiltration, smooth muscle cell proliferation, collagen content, and TGF-beta1 expression were assessed 2 weeks (early phase) and 26 weeks (delayed phase) after irradiation, using quantitative histology and immunohistochemistry, morphometry, and real-time fluorogenic probe RT-PCR. Irradiated intestine exhibited significant histopathologic injury, reduced mucosal surface area, vascular sclerosis, intestinal ...
RADIANT{trademark} is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid {beta}-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid {beta}-source is Rhenium-188 in the form of sodium perrhenate (NaReO{sub 4}), Rhenium-188 is primarily a {beta}-emitter with a physical half-life of 17.0 hours. The maximum energy of the {beta}-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac catheterization laboratory. The delivery ...
Objective The aim of this study was to analyze the clinical results of our adaptive radiationtherapy scheme of a two-step intensity-modulated radiotherapy (IMRT) method for nasopharyngeal cancer (NPC) at Kinki University Hospital. Methods Between 2000 and 2007, 35 patients with Stage I-IVB NPC treated by IMRT were included. For all patients, treatment-planning computed tomography was done twice before and during IMRT to a total dose of 60-70 Gy/28-35 fractions (median 68 Gy). Chemotherapy (cisplatin 80 mg/m2/3 weeks x 1-3 courses) was given concurrently with IMRT for 31 patients. Results The 3- and 5-year overall survival rates for the 31 patients treated with concurrent chemotherapy were 88% and 83%, respectively. The 3- and 5-year loco-regional control rates for the 31 patients were 93%...
Asynchronous Chinese hamster ovary (CHO) cells treated with conditioning hyperthermia (10 min at 45/sup 0/C) followed immediately by x irradiation with 4 Gy at room temperature display a decreased radiation response when either irradiated, or heated and irradiated again 24 h later. In addition, conditioning by 4 Gy of x radiation alone followed at 24 h by the combined heat and radiation treatment als resulted in a larger radiation D/sub 0/. Since the differential cell-cycle responses to heat- and x-ray-induced lethality are well established for CHO cells, the potential role of cell-cycle redistribution in the observed radiation desensitization was investigated by flow cytometry. At 24 h after the combined treatment, the fraction of the cells found in the G/sub 2/ + M portion of the DNA histograms was about three times that of the controls ...
Radiation doses to workers at the Manhattan Engineer District (MED) and US Atomic Energy Commission (AEC) sites due to external irradiation during 1940--1960 are reviewed. Categorized radiation dose data were available from AEC annual reports for some years. Annual individual radiation dose data for ten MED/AEC sites for all years were available from the US Department of Energy`s (DOE) Comprehensive Epidemiologic Data Resource (CEDR). These data are combined to produce an estimate of external collective dose equivalent to 172,000 person-rems (1720 person-Sv) for 1940--1960. During this period there were 41 overexposures, 19 criticality incidents, and 3 deaths due to acute radiation syndrome among several hundred thousand workers.
The effects of eight chemicals on the inactivation rate of ultraviolet radiation on the colony building capabilities of two strains of Saccharomyces cervisae - a wild type strain and a mutant deficient in excision repair - were studied. The insecticide methoxychlor, the herbicide 2,4-dichlorophenoxyacetic acid, the fungicide pentachlorophenol and its metabolite tetrachlorohydroquinone, as well as the chemicals acrylonitrile and 2,3-dichloro-1-propene have no significant impact on the effects of UV radiation in Saccharomyces cerevisae. Depending on the concentration, trichloroethylene increases the sensitivity to UV radiation. The herbicide paraquat provides efficient protection against UV radiation at concentrations where a toxic effect cannot be observed even without UV. The results were rather similar for both strains. (orig.).
The low in vivo transduction efficiency of recombinant adeno-associated virus (rAAV) and the undesirably strong immunogenicity of adenovirus (rAdv) have limited their clinical utilization in cancer gene therapy. We have previously demonstrated that intratumoral injection of rAAV expressing a C-terminal polypeptide of human telomerase reverse transcriptase (rAAV-hTERTC27) effectively inhibits the growth of glioblastoma xenografts in nude mice. To further improve its efficacy, we combined rAAV-hTERTC27 with rAdv and investigated the efficiency of the cocktail vectors in vivo. At a nontherapeutic dose (1 x 10(8) plaque-forming units (PFUs)), rAdv-null and rAdv-hTERTC27 were equipotent in enhancing the therapeutic efficacy of rAAV-hTERTC27 (1.5 x 10(11) v.g.), and complete tumor regression was achieved in 25% of the treated animals. Importantly, the combination of rAAV-hTERTC27 and a therapeutic dose (2.5 x 10(9) PFU) of ...
Positron emission tomography (PET) is the gold standard for non-invasive assessment of myocardial viability and allows accurate detection of coronary artery disease by assessment of myocardial perfusion. Magnetic resonance imaging (MRI) provides high resolution anatomical images that allow accurate evaluation of ventricular structure and function together with detection of myocardial infarction. Potential hybrid PET/MR tomography may potentially facilitate the combination of information from these imaging modalities in cardiology. Furthermore, the combination of anatomical MRI images with the high sensitivity of PET for detecting molecular targets may extent the application of these modalities to the characterization of atherosclerotic plaques and to the evaluation of angiogenetic or stem cell therapies, for example. This article reviews studies using MRI and PET in parallel to compare their performance in cardiac ...
IntroductionThe elimination of microorganisms from the root canal system necessitates the use of combination of irrigating solutions to enhance their antimicrobial property. The combination of irrigants and their interaction sometimes could be detrimental to the outcome of the root canal therapy. The purposes of this study were (1) to evaluate the interaction between 7% maleic acid (MA) and 2% chlorhexidine gluconate solution (CHX) and to find out the availability of individual irrigant and (2) to determine the free available chlorine content when 7% MA was mixed with 2.5% sodium hypochlorite (NaOCl) solution. MethodsInteraction between MA and CHX was assessed by high-performance liquid chromatography. Available chlorine content in NaOCl was evaluated by the standard iodine/thiosulfate tit...
Summary Background There is a need for new artemisinin-based combinationtherapies that are convenient, effective, and safe. We compared the efficacy and safety of pyronaridine-artesunate with that of artemether-lumefantrine for treatment of uncomplicated P falciparum malaria. Methods This phase 3, parallel-group, double-blind, randomised, non-inferiority trial was undertaken in seven sites in Africa and three sites in southeast Asia. In a double-dummy design, patients aged 3-60 years with uncomplicated P falciparum malaria were randomly assigned in a 2:1 ratio to receive pyronaridine-artesunate once a day or artemether-lumefantrine twice a day, orally for 3 days, plus respective placebo. Randomisation was done by computer-generated randomisation sequence in blocks of nine by study centre....
This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.
This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.
We present the case of a 12-year-old girl who presented with a pathological fracture through a benign-appearing osteolytic lesion that was presumed to represent fibrous dysplasia. The fracture healed, and over the next 2.5 years there was further refracturing and healing with progressive osteolysis. A biopsy was performed and revealed Ewing's sarcoma. The disease was locally controlled by neoadjuvant chemotherapy and radiationtherapy. The patient is disease free with excellent function 6 years following the discovery of the lesion. We illustrate and discuss the sequence of events. (orig.)
Two patients are described in whom sunburn and electron beam radiodermatitis, respectively, were critical determinants in localizing the initial presentation of drug eruptions. In the first instance, a severe sunburn of the back and thighs was followed 7 months later by the appearance of a toxic epidermal necrolysis drug reaction to trimethoprim-sulfamethoxazole in the exact sites of the previous bullous sunburn reaction. In the second patient, a radiodermatitis of the left upper arm due to electron beam therapy for metastatic breast cancer was followed 7 weeks later by a codeine drug reaction confined to the area of the radiodermatitis. In both instances, oral rechallenge with the offending drug reproduced the eruption.
The radiation properties of the #alpha# emitter "2"1"1At are in favor of its application malignant tumor therapy. As a basis for further investigations the biokinetics of At"-, At x H_2O, At I_2"-, and [At(thio)_2]"+ were determined after i.v. injection into healthy and tumor-bearing mice. The estimation of the ion mobility of the carrier-free compounds allowed the use of uniquely characterized initial compounds. The organ distribution of all species examined was similar to the distribution of astatide. Accumulation was found in the thyroid and other inner organs. (author).
We encountered a case of Ewing's sarcoma. The patient was a 19 year-old girl, who visited a local physician because of pain in the left scapular region, and was referred to us. Roentgenograms of her left scapula revealed an irregular moth-eaten shadow which was suspected to be a malignant bone tumor. The histological diagnosis of Ewing's sarcoma was comfirmed by needle biopsy. The initial stage of treatment consisted of radiationtherapy (6000 rads) and chemotherapy (VAC and ADR). At the end of the initial stage, the symptoms were improved, the size of the local lesion was reduced on the roentgenogram and there was no evidence of distant metastases. (author).
Twenty-seven histologically confirmed cases of localised Ewing's sarcoma were treated by two different regimes. Radiotherapy alone was used in 13 cases and a combination of chemotherapy and radiotherapy in 14. Single agent chemotherapy (cyclophosphamide) was given sequentially in nine patients and cyclophosphamide and actinomycin-D in five. There is a significant difference in the response to these different regimes. Only 69.2% of patients treated by radiotherapy alone were disease-free, for a median period of 10.4 months and metastases were noticed in 53.8% of cases. The disease-free survival in patients treated by combinationtherapy (radiotherapy and chemotherapy) was 18.4 months and metastases were seen in only 42.9%. However, no metastases were seen in patients who received cyclophosphamide and actinomycin-D, during a period of 14 months and only one patient showed residual disease. It is concluded that the addition of ...
The effect of UV radiation in the wavelength region 230 nm to 302 nm on the ability of an irradiated mammalian cell to reactivate UV-irradiated mammalian virus was tested. An action spectrum for radiation enhanced reactivation (RER) is presented. The shape of the action spectrum points to a combined nucleic acid-protein target for UV radiation effects on this cellular parameter. An analysis of the results of others involving the biochemical and photobiological events involved in RER does not allow us to distinguish which macromolecule is the major contributor to this effect. Studies involving an analogous phenomenon in bacteris (Weigle reactivation) imply that RER and WR amy involve similar mechanisms. (author).
Current information on the use of ionizing radiation for improving the storage of subtropical fruits like citrus, grapes, and avocados is reviewed. The feasibility of applying radiation either alone or in combination with other physical or chemical treatments for the control of postharvest fungal diseases is considered. Irradiation effects on the physiology of the fruits as related to respiration, ethylene evolution, changes in major chemical constituents, and quality are discussed. The recent trends in the possible use of irradiation as an alternative treatment to chemical fumigants for disinfestation of citrus and avocados and the prospects for the future application of irradiation for preservation of some of these fruits are outlined. 128 references.
Purpose : To detect differentially expressed genes in the patients with uterine cervical cancer during the radiationtherapy. Materials and Methods : In patients with biopsy proven uterine cervical cancer, we took a tumor tissue just before radiationtherapy and at 40 minutes after external irradiation of 1.8 Gy. Total RNAs isolated from non-irradiated and irradiated tumor tissue samples were analyzed using the differential-display reverse transcription-polymerase chain reaction (DDRT-PCR). Complementary DNA (cDNA) fragments corresponding to differentially expressed messenger RNAs(mRNAs) were eluted, and cloned. The differential expression of the corresponding mRNAs was confirmed by reverse northern blot. Differentially expressed cDNA bands were sequenced. Nucleotide sequence data were analyzed in the Gene Bank and EMBL databases via the BLAST network server to identify homologies to known genes or cDNA ...
Background and purpose: In order to investigate the feasibility, toxicity and antitumor efficacy of hyperfractionated radiationtherapy, 37 adult patients with incompletely resected supratentorial low-grade glioma were entered into a phase II study. Materials and methods: The radiationtherapy dose was 55 Gy in 50 fractions in 25 treatment days over 5 weeks to the tumor plus a 2-cm margin, with an additional 17.6 Gy given in 16 fractions in 8 treatment days over 1.5 weeks to the tumor plus a 1-cm margin, using 1.1 Gy b.i.d. fractionation with a 6 h interfraction interval. The total tumor dose was 72.6 Gy in 66 fractions in 33 treatment days over 6.5 weeks. Results: The median survival time (MST) for all 37 patients has not yet been attained, while 5- and 7-year survival rates were 75% and 69%, respectively. The median time to tumor progression (MTP) has also not yet been attained, while 5- and 7-year ...
Changes in the phosphate metabolism of the transplanted SCCVII (squamous cell carcinoma VII) tumor were studied before and after irradiation using in vivo [sup 31]P-magnetic resonance spectroscopy (MRS). Phosphocreatine (PCr), [gamma]-, [alpha]-, [beta]-ATP, inorganic phosphate (Pi), phosphomonoester (PME), and phosphodiester (PDE) were detected in [sup 31]P-MR spectra of tumor tissues. The curve fitting method was employed for calculating each peak of [sup 31]P-MR spectra (PCr, [beta]-ATP, Pi, PME, PDE). The values of PCr, PCr/Pi, [beta]-ATP/Pi and pH decreased in proportion to the growth of tumor, whereas that of Pi, PME and PDE increased. But the changes of [beta]-ATP were minimal in degree. Based on the fact that the ratio of PCr/Pi highly correlated with tumor volume and showed the most remarkable change among various parameters, it might be the useful index for the tumor growth. Because the phospholipid metabolite PME was detected in the earlier stage of tumor growth, PME might ...
The purpose of the current study was to evaluate the difference in prognostic factors between stage IB and II uterine cervical carcinoma patients treated with postoperative radiationtherapy. Between May 1988 and May 1998, a total of 94 patients including 47 patients with stage IB and 47 patients with stage II uterine cervical carcinoma were treated with postoperative radiationtherapy at Tokyo Metropolitan Komagome Hospital. All patients were treated with 10 MV X-rays using an anterior-posterior parallel opposed field which covered the whole pelvis. Fractionation was 2 Gy per day, five fractions per week, to a total dose of 50 Gy. The 5-year overall survival rates of stage IB and II were 89.4% and 79.3%, respectively. In multivariate analysis for all patients, lymph node status, histology, and surgical margin status were recognized as prognostic factors. Limited to stage IB patients, lymph node status ...
Purpose. We report a case of Ewing's sarcoma in the right distal femur in a 6-year-old male to demonstrate how dynamic contrast-enhanced magnetic resonance imaging (DEMRI) findings predicted histopathology. Materials and methods. DEMRI was performed at presentation and during and after completion of chemotherapy and radiationtherapy. Histopathologic studies were done at presentation, at 77 weeks (20 weeks after a pathological fracture), and from the en bloc resection at 104 weeks. Results. DEMRI predicted the early tumor response, absence of tumor recurrence, presence of necrosis and lack of fracture healing, confirmed by histopathology. Conclusion. DEMRI is a clinically useful tool in managing Ewing's sarcoma. (orig.)
Endothelial dysfunction is involved in radiation responses in many normal tissues, including intestine. Endothelium-directed interventions ameliorate intestinal radiation injury (radiation enteropathy) in animal models, and anecdotal reports also suggest a beneficial effect of heparin. This study assessed low molecular weight heparin as an intestinal radiation response modifier. Rats underwent localized small bowel irradiation. Groups of rats were treated with saline, nadroparin (3 mg/kg/d), or a non-anticoagulant heparin (SR80258, 3 mg/kg/d), from 3 days before to 2 weeks after irradiation. The intestinal radiation response was assessed 2 weeks and 6 weeks after irradiation using quantitative histology; morphometry, and cellular and molecular end-points. Compared to vehicle-treated controls, nadroparin significantly exacerbated structural radiation injury, ...
Radiation-and-thermal-combined degradation of some kinds of cable insulating and jacketing materials was evaluated by accelerated aging tests. Plasticized polyvinyl chloride (PVC), silicone rubber, crosslinked and non-crosslinked halogen-free flame-retardant polyolefins (NH-XLPO and NH-PO) and ethylene-propylene rubber (EP rubber) of experimental formulation were degraded at accelerated rates, that are 50-1000 times the degradation rate under standard conditions (e.g.; 1Gy/h, 50degC), and a method to assess the lifetime of these materials under standard conditions was studied. The degradation was investigated by measuring tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for these materials were in proportion to the increase in accelerated rate. The PVC lifetime estimated from sequential aging tests had a tendency to extend beyond that from simultaneous aging tests, while the lifetime of other materials estimated ...
In this updated second edition, the order of contents of the textbook has been reorganized. It has been divided into main parts: Basic Science and Clinical Nuclear Medicine. Basic Science, Part I, encompasses basic physics, radiation protection, interaction of radiation with matter and radiation detection, imaging, nuclear pharmacy, and radiation biology. Part II, Clinical Nuclear Medicine, covers the central nervous system, bone, gastroenterology (liver/spleen), cardiovascular system, pulmonary system, genitourinary system, thyroid and endocrine systems, gallium studies, radioassay, hematology, and therapy. The total number of pages of the current edition is increased to 250 from the 213 of the first edition but there are fewer questions because those in the basic science area have been carefully selected to 60 of the original 98 questions. Compared with the previous edition, there ...
A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the emitted radiation to bend toward the detector as rays parallel to the detector axis of the detector. The collimator may be a hollow cylinder ...
Success in improving treatment outcomes in childhood cancer has been achieved almost exclusively through multicenter and multidisciplinary clinical and applied research over several decades. While biologically rational as well as empirical approaches have led to combination chemotherapy and multimodality approaches to therapy, which have given rise to evidence-based practice standards, similar scientific rigor has not always been as evidently applied to modalities utilized to assess initial disease burden and, more important, response to investigational approaches to therapy. As the empirical approach to therapeutic advances has likely maximized its benefit, future progress will require translation of biologic discovery most notably from the areas of genomics and proteomics. Hence, attempts to improve efficacy of therapy will require a parallel effort to minimize collateral damage of future therapeutic ...
The evaluation of radiotherapy and surgery as exclusive local treatment in comparably selected subgroups of patients with Ewing's sarcoma on the basis of the CESS 86-data. In the German multicenter Ewing's sarcoma study CESS 86, treatment consisted for four 9-week-courses of VACA- or VAIA-chemotherapy plus local therapy. VACA (vincristine, actinomycin D, cyclophosphamide, adriamycin) was given in low-risk extremity tumors with a tumor volume below 100 cm"3. Highrisk patients with central lesions or a tumor volume >100 m"3 received VAIA (ifosfamide instead of cyclophosphamide). Local therapy started after one complete chemotherapy course in week 10. Based on an individual decision in each patient, local therapy was either radical surgery or resection plus postoperative irradiation with 45 Gy or definitive radiotherapy with 60 Gy. Because of poor results with radiotherapy in a preceeding study, it was intended to restrict ...
A system is claimed for multiplexing or demultiplexing pulsed laser radiation having an acousto-optical device which is electrically controlled to switch a common path of high pulse rate laser radiation between a plurality of spatially distinct paths for relatively lower pulse rate laser radiation at which the pulses are sequenced according to a predetermined time pattern. The acousto-optical element typically includes a Bragg cell which is electrically driven by a set of distinct frequencies, causing deflection of radiation passing therethrough at a predetermined set of angles whereby pulsed radiation on a single path may be distributed onto the plural separate paths or radiation on plural separate paths of time-sequenced pulses of radiation can be combined into a single path of augmented pulse rate. The control of the ...
For the safety of astronauts and to ensure the stability and integrity of the genome of microorganisms and plants used in bioregenerative life support systems, it is important to improve our knowledge of the combined action of (space) radiation and microgravity. The SOS-LUX-TOXICITY test, as part of the TRIPLE-LUX project (accepted for flight at Biolab in Columbus on the International Space Station, (ISS)), will provide an estimation of the health risk resulting from exposure of astronauts to the radiation environment of space in microgravity. The project will: (i) increase our knowledge of biological/health threatening action of space radiation and enzymatic DNA repair; (ii) uncover cellular mechanisms of synergistic interaction of microgravity and space radiation; (iii) provide specified...
Using the radiation chemical method it is possible to prepare wood-plastic composites using doses of 1 to 2.5 kGy. The impregnation mixture in the wood gelatinates and subsequent curing using chemical initiators takes place without outflow of the mixture from the wood and without formation of incrustations. The basic components of the impregnation mixtures used were unsaturated polyester resins; styrene or methyl methacrylate was used as the thinner. The proven initiator of polymerization was 2,2'-azobisisobutyronitrile. The technology is described of wood impregnation and radiation or chemical curing. The effects were monitored of viscosity, temperature, radiation dose and the concentrations of the individual components of the impregnation mixtures and initiators of polymerization on the process of the preparation of wood-plastic composites.
Plants require solar radiation for photosynthesis and their growth is directly related to the amount received, assuming that other environmental parameters are not limiting. Therefore, precise estimation of photosynthetically active radiation (PAR) is necessary to enhance overall accuracies of plant growth models. This study aimed to explore the PAR radiant flux in the San Francisco Bay Area of northern California. During the growing season (March through August) for 2?years 2007?2008, the on-site magnitudes of photosynthetic photon flux densities (PPFD) were investigated and then processed at both the hourly and daily time scales. Combined with global solar radiation (R S) and simulated extraterrestrial solar radiation, five PAR-related values were developed, i.e., flux density-based PAR ...
The interaction of thermal radiation with conduction and convection in thermally developing absorbing, emitting, nongray gas-particulate turbulent suspension flow through a circular tube is investigated. The contribution of thermal radiation is obtained through evaluation of the total hemispherical emittance of the particulate cloud and through evaluation of single band absorptances for molecular gases, modified to account for the interaction with the particles. The governing differential equation is derived as a (nonlinear) energy equation, coupled with integral equations to find the thermal radiation contributions. The energy equation is solved numerically by an implicit finite difference method with an iterative procedure. Qualitative results for Nusselt numbers are shown for a variety and range of parameters, such as optical thickness of particulates and single molecular gas bands, relative gas band position and band ...
The interaction of thermal radiation with conduction and convection in thermally developing absorbing, emitting, non-gray gas particulate turbulent suspension flow through a circular tube is investigated. The contribution of thermal radiation is obtained through evaluation of the total hemispherical emittance of the particulate cloud and through evaluation of single band absorptances for molecular gases, modified to account for the interaction with the particles. The governing differential equation is derived as a (nonlinear) energy equation, coupled with integral equations to find the thermal radiation contributions. The energy equation is solved numerically by an implicit finite difference with its iterative procedure. Qualitative results for Nusselt numbers are shown for a variety and range of parameters, such as optical thickness of particulates and single molecular gas bands, relative gas band position and band width, ...
As a series of estimations of population doses and of risk estimates from medical exposures in Japan, the malignancy significant dose (MSD) and the fatal malignant risk from beam therapy were estimated based on a nationwide survey of radiotherapeutic treatments, using a malignancy significant factor and a weighting factor determined from the data on the cancer mortality among the atomic bomb survivors in Nagasaki. The effective dose was defined as a sum of the product of the weighting factor and the organ or tissue doses with respect to the malignant diseases. The organ or tissue doses were determined with ionization chambers placed at the positions of their center in a MixDp-phantom simulated lung tissues by a block of cork, using a telecobalt unit, a conventional X-ray unit and a medical linear accelerator. The organ or tissue doses were categorized into three dose components; namely 1) dose from useful beams; 2) scattered radiation dose from ...
Background: The outcome of acute myocardial infarction (AMI) complicated with cardiogenic shock is poor. The aim of this study was to analyse, whether upfront abciximab administration could improve the outcomes of cardiogenic shock. Methods: This multicentre open trial randomized 80 patients with AMI complicated by cardiogenic shock expected to undergo primary PCI into group A (routine upfront-pre-procedural-abciximab bolus followed by 12-h abciximab infusion) and group B (standard therapy). The study primary objective was 30-day combined outcome (death/reinfarction/stroke/new severe renal failure). Results: PCI was technically successful in 90% (A) versus 87.5% (B) patients. Abciximab was used in 100% (A) versus 35% (B). The primary endpoint occurred in 17 group A patients (42.5%) and 11 ...
A prototype electron applicator system providing circular and rectangular fields for use in intraoperative electron beam therapy with a Varian Clinac 18 linear accelerator has been fabricated. The dosimetric properties of this system for a variety of electron-beam energies, applicator sizes, and x-ray collimator settings was documented. Significant findings include: (a) surface dose values are in excess of 90% for electron energies of 12 MeV and above; (b) for the 18-MeV beam, the deepest depth where the central axis dose is 90% of its maximum value is in excess of 50 mm for circular applicators whose diameters are in excess of 5 cm; and (c) the treatment time to deliver 1000 rads ''given dose'' (at a given dose rate of 300 MU/min) is on the order of 3--4 min. Cross-field behavior is acceptable for the intended application and x-ray contamination is less than 4% for any applicator/electron energy combination. A system for irregular field ...
The low in vivo transduction efficiency of recombinant adeno-associated virus (rAAV) and the undesirably strong immunogenicity of adenovirus (rAdv) have limited their clinical utilization in cancer gene therapy. We have previously demonstrated that intratumoral injection of rAAV expressing a C-terminal polypeptide of human telomerase reverse transcriptase (rAAV-hTERTC27) effectively inhibits the growth of glioblastoma xenografts in nude mice. To further improve its efficacy, we combined rAAV-hTERTC27 with rAdv and investigated the efficiency of the cocktail vectors in vivo. At a nontherapeutic dose (1 x 108 plaque-forming units (PFUs)), rAdv-null and rAdv-hTERTC27 were equipotent in enhancing the therapeutic efficacy of rAAV-hTERTC27 (1.5 x 1011?v.g.), and complete tumor regression w...
Because toxicity with the use of 3000 centiGray (cGy) of total lymphoid irradiation (TLI) was observed in an earlier study, 2000-cGy treatments were delivered in a 2-portal format to 7 patients and in a modified 3-portal fashion to 6 patients, as part of a randomized, investigator-blinded trial of TLI treatment for refractory rheumatoid arthritis. Analysis of combined data from the 13 patients revealed statistically significant improvement in 5 clinical indicators of disease activity at the end of TLI and 6 and 12 months later, accompanied by T4-specific immunosuppression. Management considerations resulted in the introduction of prednisone therapy in 5 patients, methotrexate in 4, and azathioprine in 1 during the interval of 8-12 months post-TLI. Herpes zoster occurred in 5 patients prior to the initiation of this additional therapy. These data indicate that, in patients with rheumatoid arthritis, a TLI dose of 2000 cGy is ...
In searching modulators of immunity and hematopoiesis among natural products, being used as foods, six herbs exhibited lymphocyte proliferation in vitro, and six exhibited augmentation of hematopoietic cell growth. The combined treatments showed synergistic effects of lymphocyte proliferation and of hematopoietic cell growth. On the other hand, we found four effective oriental medicinal prescriptions, used as energy tonic or blood-building decoctions, for survival and regeneration of hematopoietic cells and for protection of stem cells of intestinal crypt in irradiated mice. On the basis of these results, extracts from combinations of herbs were made in expectation of higher effects in the three respects. In immuno modulation activity by the two combinations of herbs was confirmed in mice. In culture of bone narrow cells, growth improvement of non-adherent precursor and induction of cytokine expression by herb mixture ...
Portal verification images were generated from the photon contamination in electron beams produced by a linear accelerator during treatment of patients receiving high-energy electron radiationtherapy (8-14 MeV). An experimental storage phosphor system was used to record the images and display them on laser-printed film. Images were obtained from four or more treatment fractions from 21 cases of head and neck cancer. Precision in field placement was estimated by determining the position of a selected anatomic landmark relative to the center of the field for each series of images. The average standard deviation in the field-position measurements was 3.8 mm. Several procedural problems were also detected and corrected after review of the verification images. The results indicate that the emphasis placed on monitoring and control of field-positioning error in high-energy electron treatments should be similar to the emphasis placed on this aspect ...
Background: the authors report on the conception and first clinical application of a donut-shaped high-dose configuration for proton therapy (PT). This approach allows one to intensify target volume dose coverage for targets encompassing a critical, dose-limiting structure - like here, the cauda equina -, whilst delivering minimal dose to other healthy structures surrounding the target, thereby reducing the integral dose. Methods and results: intensity-modulated PT methods (IMPT) for spot scanning were applied to create and deliver a donut-shaped high-dose configuration with protons, allowing treating > 75% of the target with at least 95% of the prescribed dose of 72.8 CGE, whilst restricting dose to the cauda equina to 60-65 CGE. Integral dose was lower by a factor of 3.3 as compared to intensity-modulated radiotherapy with photons (IMXT). Conclusion: IMPT and spot scanning technology allow a potentially clinically useful approach which is also applicable ...
Background: the authors report on the conception and first clinical application of a donut-shaped high-dose configuration for proton therapy (PT). This approach allows one to intensify target volume dose coverage for targets encompassing a critical, dose-limiting structure - like here, the cauda equina -, whilst delivering minimal dose to other healthy structures surrounding the target, thereby reducing the integral dose. Methods and results: intensity-modulated PT methods (IMPT) for spot scanning were applied to create and deliver a donut-shaped high-dose configuration with protons, allowing treating > 75% of the target with at least 95% of the prescribed dose of 72.8 CGE, whilst restricting dose to the cauda equina to 60-65 CGE. Integral dose was lower by a factor of 3.3 as compared to intensity-modulated radiotherapy with photons (IMXT). Conclusion: IMPT and spot scanning technology allow a potentially clinically useful approach which is also applicable to ...
Between 1970 and 1981, 348 patients underwent definitive irradiation. Of these patients 6 (1.7 per cent) sustained severe rectal injury as manifest by major rectal bleeding, rectal stricture, rectal mucosal slough and rectal ulceration. Severe rectal injury was observed in 0 of 13 patients (0 per cent) treated with 125iodine, 3 of 329 (1 per cent) treated with 6,400 to 6,800 rad external irradiation, 2 of 39 (5 per cent) treated with 7,000 to 7,300 rad external irradiation, and 1 of 7 (14 per cent) treated with 198gold and external irradiation. The impact of radiation dose, radiationtherapy technique and surgical trauma was assessed. Rectal injury was managed by supportive measures in 2 patients and by diverting colostomy in 3 with benefit. One patient underwent abdominoperineal resection. A small bowel fistula and an intra-abdominal abscess developed, and the patient died.
Experiments were carried out on mice and the subjects irradiated for cancer therapy to evaluate the protective efficacy of a Chinese medicinal herb-compound (CMHC). The lethality and the degree of leucopenia caused by radiation in mice medicated with CMHC were significantly less in comparison with control mice (p less than 0.01 and p less than 0.001, respectively). CMHC significantly improved the WBC and the thrombocytes in irradiated workers (p less than 0.01 and p less than 0.001, respectively). The WBC count of 40 patients under radiotherapy while treated with CMHC recovered from 3450 +/- 77/c.mm to 5425 +/- 264/c.mm (p less than 0.001); whereas, in the control group, without any medication, the WBC count dropped significantly (p less than 0.001). Our results revealed the applicabilities of CMHC in protection against radiation damage in spaceflight and in other fields.
The manufacture and use of wood/plastic composite (WPC) as an example of wood matrix and wood sawdust/plastic composites (SDP) as an example of plastic matrix are reviewed. The raw material for WPC are mostly vinyl monomers, particularly methyl methacrylate and styrene. The reaction in WPC polymerization is radical polymerization. Researches on the radiation sources mostly resulted in gamma-ray. Electron beam can be applied only to thin products. The future use of WPC may be for furnitures, sporting goods, decorative parts and the like. Vital study on the reduction of manufacturing costs is required, for example, the improvement of reaction and the adoption of continuous process must be considered. The raw materials for SDP are wood sawdust, vinyl monomer (mostly methyl methacrylate) and resins. Electron beam accelerators are the most preferable radiation source because of its high efficiency and safe operation. SDP shows good forming property. ...
The proton beam has an advantage of the sharp dose falloff in dose distribution called Bragg peak while conventional radiationtherapy modalities such as photons exhibit considerable amount of exit dose. To take advantage of this property it is important to know the exact location of the distal dose falloff. An error can cause overdose to the normal tissue or underdose to the tumor volume. The only way of finding out the dose distribution in-situ in particle therapy is to measure the gammas produced by nuclear reactions with tissue materials. Two kinds of gammas can be used: one is prompt gamma and the other is coincident gamma from the positron-emission isotopes. We chose to detect prompt gammas, and developed a prompt gamma scanning system (PGS). The proton beams of the proton therapy facility at National Cancer Center were used. The gamma distribution was compared to the dose distribution measured by ...
Thirty-seven patients with primary nonresectable intrahepatic cholangiocarcinoma (57% with prior treatment and/or metastasis) were prospectively treated with external radiation, chemotherapy, and "1"3"1I labelled anti-CEA. Therapy began in all trials with whole liver irradiation (21.0 Gy, 3.0 Gy/Fx, 4 days/week, 10 MV photons) with alternate treatment day chemotherapy (Adriamycin, 15 mg + 5-FU, 500 mg). One month after external beam therapy, chemotherapy was given (Adriamycin, 15 mg + 5-FU, 500 mg) followed the next day by the first administration of "1"3"1I anti-CEA. The treatment schedule used was 20 mCi day 0; 10 mCi day 5 as an outpatient. This schedule was derived from tumor dose estimates which indicated that 20 mCi (8-10 mCi/mg IgG) was sufficient to achieve tumor saturation with a tumor effective half-life of 3 to 5 days, depending upon the species of animal from which the antibody was obtained. The median tumor ...
Previous behavioral and pharmacological studies have implicated endorphins in radiation-induced locomotor hyperactivity of the C57BL/6J mouse. However, the endogenous opiate(s) responsible for this behavioral change have not been identified. The present study measured beta-endorphin-like immunoreactivity (beta-END-LI) in brain, blood, and combined brain and pituitary samples from irradiated and sham-irradiated C57BL/6J mice. After radiation exposure, levels of beta-END-LI decreased significantly in the brain. A similar, but not statistically significant, decline was measured in combined brain and pituitary samples. Concentrations of blood beta-END-LI were not changed by irradiation. These radiogenic changes in beta-END-LI are in some ways similar to those observed after other stresses. However, radiation-induced locomotor hyperactivity may be mediated more by alterations of ...
The D2 antidopaminergic drug Domperidone was evaluated singly and in combination with synthetic adrenocorticoid and an H2 antihistamine for its ability to reduce the acute emetic effects of /sup 60/Co whole-body radiation. Random-source adult male dogs were fasted 12 hours, fed a standard meal, injected 44 minutes later and irradiated 47 minutes after that. Four groups of dogs were radiated after drug injections as follows: saline (Con), domperidone (Dom), cimetidine + thiethylperazine (Cim+Thi), and dexamethasone + domperidone + cimetidine (Dex+Dom+Cim). Drug quantities for dogs represented 10 mg Dom, 10 mg Thi, 20 mg Dex, and 300 mg Cim for an average human (70 ka, 1.8 m2). Subjects were exposed on an up-down schedule to determine the radiation necessary to produce vomiting in 50% (ED50) of each group. Emesis onset times, offset times, and number of episodes were recorded. The ED50 of Dex+Dom+Cim was ...
Colorectal carcinoma is a highly prevalent and common cause of cancer in Taiwan. There is still no available cure for this malignant disease. To address this issue, we applied the multimodality of molecular imaging to explore the efficacy of diagnostic and therapeutic nanoradiopharmaceuticals in an animal model of human colorectal adenocarcinoma [colorectal cancer (CRC)] that stably expresses luciferase (luc) as a reporter. In this study, an in vivo therapeutic efficacy evaluation of dual-nanoliposome (100 nm in diameter) encaged vinorelbine (VNB) and "1"1"1In-oxine on HT-29/luc mouse xenografts was carried out. HT-29/luc tumor cells were transplanted subcutaneously into male SCID mice. Multimodality of molecular imaging approaches including bioluminescence imaging (BLI), gamma scintigraphy, whole-body autoradiography (WBAR) and in vivo tumor growth tracing, histopathology and biochemistry/hematology analyses were applied on xenografted SCID mice to study the treatments with 6% ...
Patients with haemarthros of the knee were examined by MRI and arthroscopy to identify the bleeding source and to determine surgical or conservative therapy. A prospective study was performed on 120 patients who underwent MRI and arthroscopy, point lesions and bleeding sources were documented separately on a standardised form. Arthroscopy demonstrated a ruptured anterior cruciate ligament in 86%, meniscal tears in 55%, disruption of collateral ligaments in 17%, osteochondral lesions in 5% and tears of capsule or plicae in 13%. Disruption of cruciate ligaments caused haemorrhage in all but three cases. In contrast, only meniscal tears located very adjacent to the meniscal basement had bled. Those types of osteochondral lesions caused haemorrhage characterised on MRI by destruction of the subchondral plate and overlying cartilage. Severe lesions of the knee were diagnosed by MRI in 71% to 100%, slight lesions in 13% to 40% of the cases. Single, ...
This paper gives a general description of functions, usages and system configurations of the instruments and their major units or components of the radiation monitoring system, as well as the status and technical gap between domestic and foreign technologies. And then the paper also puts forward an idea on product R and D, i.e. combination of independent R and D and innovation, assimilation and re-innovation of foreign advanced technology at present situation in order to keep pace with the rapid development of nuclear power in China and achieve the goal of localization of nuclear power equipment. (authors)
One of the greatest opportunities for using of biomass as a precursor in the production of polymeric materials is the lignocellulose composites that can combine high performance with low costs. This work is a initial study on the production of a lignocellulose reinforced polyethylene composite. A compatibilization made by a induced gamma radiation grafting reaction was used to increase the adhesion between the matrix and the reinforced or filled fibers. The lignocellulose materials were exposed to gamma radiation in order to promote a molecular degradation and increase its reactivity. The polymer, the lignocellulose material and the compatibilization were processed by extrusion and the composite produced by this process were characterized by mechanical tests. (author)
A passive integrating radon dosemeter is described. The radon dosemeter is based on radon adsorption on activated charcoal. By placing TLD crystals inside an open charcoal container, the beta radiation from radon daughters, produced by the decay of adsorbed radon, is detected continuously during the exposure time. After closing the container, radiation will still be detected by the TLD crystal. Calibration procedures are reported and the suitability of the dosemeter is discussed. The dosemeter proved to be suitable for measurements during periods from a few days to two weeks both in domestic and mine atmospheres.
Abstract: The current financial crisis has now led most major central banks to rely on quantitative easing. The unique Japanese experience of quantitative easing is the only experience which enables us to judge this therapy's effectiveness and the timing of the exit strategy. In this paper, we provide a new empirical framework to examine the effectiveness of Japanese monetary policy during the ''lost'' decade and quantify the effect of quantitative easing on Japan's activity and prices. We combine advantages of Markov-switching VAR methodology with those of factor analysis to establish two major findings. First, we show that the decisive change in regime occurred in two steps: it crept out from late 1995 and established itself durably in February 1999. Second, we show for the first time th...
A retrospective study of Ewing's Sarcoma at The Armed Forces Malignant Diseases Treatment Centre, Command Hospital, Pune, is presented. A total of 38 cases over a period of thirteen years have been studied. Males predominate slightly, and the common age group on presentation has been in the second and third decade. Humerus, pelvis and femur are the bones commonly affected. The initial line of management has been primarily radiotherapy, which has been over the years supplemented by combination chemotherapy. All the cases achieved remission, though only 32 cases (84 per cent) had complete remission, and the remaining only partial remission. The overall survival in those offered aggressive therapy has been over 50 per cent in two years. The present policy in the management of these cases is discussed. (author). 4 tabs.
Hepatocellular carcinoma (HCC) represents a major health problem as it afflicts an increasing number of patients worldwide. Albeit most of the risk factors for HCC are known, this is a deadly syndrome with a life expectancy at the time of diagnosis of less than 1?year. Definition of the molecular principles governing the neoplastic transformation of the liver is an urgent need to facilitate the clinical management of patients, based on innovative methods to detect the disease in its early stages and on more efficient therapies. In the present study, we have combined the analysis of a murine model and human samples of HCC to identify genes differentially expressed early in the process of hepatocarcinogenesis, using a microarray-based approach. Expression of 190 genes was impaired in murine ...
Fatty acid esters such as Lipiodol or Ethiodol are known to selectively localize in vascular hepatocellular carcinomas (HCC), following intraarterial hepatic administration. Lipiodol was labeled with radioactive /sup 131/I and administered in 47 patients with HCC for both imaging and therapy. The short term preliminary results suggest radiolabeled Lipiodol is effective in eliminating ascites, shrinking the tumor by a high internal radiation dose, and in improving symptomatology of these tumors. In the future, /sup 90/Y, which is a stronger pure beta-emitter (maximum beta energy of 2.27 MeV, a half life of 64 h, and a maximum penetration or beta range of 11mm), than /sup 131/I will be used for more effective treatment of HCC.
The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiationtherapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the gamma function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the l...
Boron neutron capture therapy (BNCT) trials for human glioma (glioblastoma multiform) were initiated September 1994 at the Brookhaven National Laboratory (BNL). Patients are given p-boronophenylalanine-fructose (BPA-F) intravenously as the boron carrier followed by exposure to the epithermal-neutron beam at the Brookhaven Medical Research Reactor (BMRR). The initial phase of the study is to determine safety and toxicity of the drug and irradiation procedure. The epithermal-neutron beam was developed in a joint effort by BNL and Idaho National Engineering Laboratory (INEL) researchers. For the human trials, treatment planning and radiation dose estimation is performed using the BNCT-Rtpe and the rtt-MC computer codes developed by the INEL BNCT program. This paper discusses our initial experience using these treatment planning codes for human subjects. The basic principles of BNCT have been previously documented.
To evaluate the usefulness of radiationtherapy alternative to surgery for clinical N0-N1 non-small cell lung cancer (NSCLC). From 1976 through 1989, 116 patients with NSCLC without mediastinal involvement were treated with definitive radiationtherapy alone at Gunma University Hospital. All patients were treated with once-daily standard fractionation using 10 MV X-rays. The total dose ranged from 60 Gy to 80 Gy. The actuarial 2- and 5-year survival rates of the entire group were 43% and 20%, respectively with a median survival time of 19 months. The survival of 76 patients with stage T2 tumors was significantly better than that of 28 patients with T3 tumors (mean survival time 21 versus 15.5 months; p<0.05). Sixty-two patients with tumors less than 5 cm in diameter had a 2-year progression rate of 20%, in comparison with 39% of 54 patients with tumors greater than 5 cm. The difference of survivals ...
This introductory paper surveys potential sources of electric magnetic, and electro-magnetic fields. Various cases are discussed to exemplify the total frequency range: nuclear magnetic resonance tomography, high-voltage transmission lines, transformer stations, effect lighting balls, military transmitters, transmitter towers of the Postal Services and other operators, mobile radiotelephone equipment, large broadcasting transmitters, radar radiation, high-frequency heat therapy. There is evidence suggesting that electric, magnetic and electro-magnetic fields may possibly represent a certain nuisance or health hazard even at field strength occuring in equipment used for every-day-life purposes, with an emphasis on their possible actions and effects in children and adolescents. The author discusses, in conclusion, the aerial equipment ordinance issued by Lower Saxony. (Uhe).
The purpose of this study was to compare 2 adaptive radiotherapy strategies with helical tomotherapy. A patient having mesothelioma with mediastinal nodes was treated using helical tomotherapy with pretreatment megavoltage CT (MVCT) imaging. Gross tumor volumes (GTVs) were outlined on every MVCT study. Two alternatives for adapting the treatment were investigated: (1) keeping the prescribed dose to the targets while reducing the dose to the OARs and (2) escalating the target dose while maintaining the original level of healthy tissue sparing. Intensity modulated radiotherapy (step-and-shoot IMRT) and 3D conformal radiotherapy (3DCRT) plans for the patient were generated and compared. The primary lesion and nodal mass regressed by 16.2% and 32.5%, respectively. Adapted GTVs and reduced plan...
Adaptive radiationtherapy for liver cancer has the potential to reduce normal tissue complications and enable dose escalation, allowing the potential for tumor control in this challenging site. Using adaptive techniques to tailor treatment margins to reflect patient-specific breathing motions and image-guidance techniques can reduce the high dose delivered to surrounding normal tissues while ensuring that the prescription dose is delivered to the tumor. Several treatment planning and delivery techniques have been developed for use in the liver, including a margin to encompass the full breathing motion, mean position techniques, which evaluate the probability of tumor location during breathing, breath hold, gating, and tracking. Patient selection, clinical workflow, and quality assurance m...
We have developed a flexible radioactive polyurethane patch incorporating {beta}-emitting radionuclide (166Ho) to treat malignant skin lesions. We covered the tumor surface (n=133) with the radioactive patch for 33.58 {+-} 5.33 minutes. Radiation dose delivered was 35 Gy for Bowen's disease (n=78), Kaposi sarcoma (n=25), actinic keratosis (n=5), and 50 Gy for BCC (n=17) and squamous carcinoma (n=8). Complete response was observed in 91.7% after the first therapeutic trial, 96.2% after 2nd and 97.7% after 4th trial with excellent cosmetic outcome for 31.15{+-}13.88 months of follow-up. Radioactive patch therapy is effective for superficial skin cancers that are impractical for surgery.
Optimum processing parameters were searched for the pilot-scale production of wood-polyester composites by irradiation of resin-impregnated wood material. The radiation initiation of the following systems were examined in wood and without wood matrix: methyl methacrylate, mixture of styrene and acrylonitryle, and their combination with unsaturated polyester. In the most cases the over-all rate of the complete polymerization process in wood matrix is proportional to the square root of the initiation rate. The parameters of the radiation technology of wood-polyester composites have been determined, using 260 TBq (7 kCi) "6"0Co radiation source. A pilot plant has been constructed using an underwater irradiation system of 1.85 PBq (50 kCi) "6"0Co. The successful production rate of 200 kg wood-polyester composite per day, as well as the application tests have demonstrated the technical feasibility of this ...
The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the W7-AS ...
Childhood cancer survivors at highest risk of developing a secondary malignancy are those with hereditary retinoblastoma. The majority of such secondary cancers will be sarcomas, most commonly of bone. One-third of these occur outside a typical radiation field, commonly in an extremity. Bone sarcoma is also the most commonly reported secondary cancer to develop among survivors of Ewing's sarcoma. In this group, radiation doses greater than 60 Gy as well as alkylating agent chemotherapy have been identified as contributors to the increased risk. The prognosis for patients with a secondary sarcoma has been poor, with few cures reported to date. However, an aggressive, combined modality approach, including radical resection, postoperative radiation, and adjuvant chemotherapy, may improve the survival rate.
An increased compendium of drugs useful in ocular motor system dysfunction has expanded our capacity to treat selected ocular motility disorders. Adjunctive therapeutic modes (e.g., Fresnel prisms and orthoptic exercises) can also be beneficial. PAN and see-saw nystagmus can be treated with baclofen. Downbeat nystagmus may respond to clonazepam therapy, and prisms may help if the nystagmus can be modified with convergence. Congenital nystagmus may respond minimally to drugs (e.g., baclofen), but prisms or surgical procedures, or both, are still the primary treatment modalities. Innovar may be helpful in patients with severe, incapacitating vestibular disorders, and scopolamine alone or in combination with promethazine may be beneficial in patients with milder ambulatory acute peripheral vestibular disorders. Benign positional vertigo is best treated initially with positional exercises before drug therapy is instituted. ...
In order to judge the potential fluorescent lamp applications of various low-pressure positive column discharges it is necessary to measure the absolute power emitted in the ultraviolet region of the spectrum. For rare-gas discharges the principle emission occurs in the vacuum ultraviolet so that it is difficult to measure the radiant emittance (power per unit area) of the resonance radiation by standard methods. Two independent techniques are discussed for measuring the radiant emittance of positive column discharges in the vacuum ultraviolet. These techniques are used to study xenon positive column discharges at the resonance wavelength of 147 nm. The first method relies on the measurement of the resonance level density by absorption techniques. The effective decay rate of the resonance level is then determined by the simulation of resonance radiation transport. These two quantities are combined to yield the radiant ...
With the practice of 10 years safe operation, Daya Bay Nuclear Power Station has established and continuously improved the management system for radiation protection and optimization (ALARA) which contains 3 basic requirements: all workers are trained, all employees are engaged in totally, and work management is implemented for the whole process. At the same time, strong efforts have been made to build the 'infrastructure' as a platform for its effective operation. This article introduces the contents and characteristics of the system and basic experiences of its effective implementation. In order to implement the management system effectively, it is necessary for NPPs to strengthen the responsibility system for radiation protection and the leading role of the radiation protection personnel, especially the role of technical support and supervision during the work with high radiation risk, emphasize the ...
From the numbers of radiographs of the different examinations and the total amount of radiological diagnostics in the GDR their possible modification by new imaging techniques is discussed under the aspects of costs and radiation burden. Film-screen-systems are of special importance, because they also will be most frequently used image recording system in future. The importance of their various properties and parameters, methods of determining these parameters as well as future developments are analyzed from the standpoint of practical requirements.
From the numbers of radiographs of the different examinations and the total amount of radiological diagnostics in the GDR their possible modification by new imaging techniques is discussed under the aspects of costs and radiation burden. Film-screen-systems are of special importance, because they also will be most frequently used image recording system in future. The importance of their various properties and parameters, methods of determining these parameters as well as future developments are analyzed from the standpoint of practical requirements. (author).
Esters of dihydric alcohols with alkenylphosphonic or alkenylphosphinic acids which are polymerizable by free radicals are described. They are combined with polymer binders, in particular water-soluble polymers, and photoinitiators forming free radicals to give photopolymerizable mixtures which are suitable for the production of photoresists and printing plates. The mixtures display low heat-sensitivity and have long shelf lives. (author) 1 tab.
It is shown that low-frequency elastic vibrations of near-surface planar defects cause high-frequency ultrasonic radiation in surrounding air. The frequency conversion mechanism is concerned with contact nonlinearity of the defect vibrations and provides efficient generation of air-coupled higher-order ultraharmonics, ultrasubharmonics, and combination frequencies. The nonlinear air-coupled ultrasonic emission is applied for location and high-resolution imaging of damage-induced defects in a variety of solid materials.
Channel plasmon polaritons (CPPs) propagating along the bottom of subwavelength grooves cut into a metal surface were recently shown to exhibit strong confinement combined with low propagation loss, a feature that makes this guiding configuration very promising for the realisation of ultra-compact photonic components. Here, the results of our investigations of CPP guiding by V-grooves cut into gold are presented, demonstrating efficient large-angle bending and splitting of radiation as well as waveguide-ring resonators and Bragg grating filters.
An improved coating for Advanced Gas Cooled Nuclear Reactor austenitic stainless steel fuel cans is described which, tests have shown, inhibits the deposition of carbon on the cans in carbon-containing ionising radiation environments. The coating comprises a refractory oxide which has been prepared by a vapour phase condensation method, in combination with a noble metal. (U.K.).
Sixteen patients with advanced cutaneous T-cell lymphoma (CTCL) with or without lymph node involvement, but without evidence of extranodal manifestations, were treated with a combination of total skin electron beam therapy (TSEB) and total nodal irradiation (TNI). Fourteen (87%) patients achieved a complete response (CR) lasting from 1 to 84+ months (median, 8+ months) from the completion of treatment. The best results occurred in 6 patients with pretumorous intracutaneous CTCL (Stages IB and IIA) where the CR has lasted in all patients from 8 to 84+ months (median about 27+ months). Radiotherapy was well tolerated with the major toxicity being bone marrow suppression. The authors conclude that combined TSEB and TNI is a relatively safe and effective treatment for patients with CTCL prior to the development of lymph node involvement. Long-term follow-up is needed to assess the curative potential of this treatment.
A combination of sustained release (SR) naltrexone (32mg/day) and bupropion SR (360mg/day) plus behavioral counseling was evaluated for the treatment of smoking cessation and mitigation of nicotine withdrawal and weight gain. Thirty overweight or obese nicotine-dependent subjects were enrolled in a 24-week, open-label study; 85% and 63% completed 12 and 24weeks, respectively. The target quit date was Week 4. Week 4-12 continuous abstinence rate was 48%, 78% of subjects achieved CO 10ppm, serum cotinine decreased from 185 to 48mg/L, and tobacco use decreased from 129 to 14 cigarettes/week. Similar results were seen at Week 24. Body weight was essentially unchanged (Week 12: -0.1%; Week 24: +0.4%). Except for a transient significant increase 1week after the target quit date (p<0.05), nicotin...
The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the ...
The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the ...
Fiber delivered laser pulses emulsify thrombus by mechanical stresses that include a combination of pressure, tension and shear stress. Laser radiation is delivered to the locality of a thrombus and the radiation is absorbed by blood, blood dot, or other present materials. The combination of a leading pressure wave and subsequent vapor bubble cause efficient, emulsification of thrombus. Operating the laser in a low average power mode alleviates potential thermal complications. The laser is operated in a high repetition rate mode to take advantage of ultrasound frequency effects of thrombus dissolution as well as to decrease the total procedure time. Specific parameter ranges for operation are described. The device includes optical fibers surrounding a lumen intended for flow of a cooling agent. The fibers may be arranged concentrically around the lumen to deliver radiation and heat ...
The interest for medicinal plants has raised again in the last decades, after overcoming a declination period caused by the advances in the researches and development of the synthetic drugs industries. This growing interest has been stimulated mainly by searching cheap and accessible alternative therapies. However, in order to have natural products based treatment in an efficient and safety way, it is necessary to guarantee the plant authenticity, finding adulterations and to assure a low level of microbiological contaminations to avoid damages to consumer's health. The decontamination method should be chosen for eliminating or reduce the microorganisms level without loss of the plant active constituents that would destroy its therapeutic action. At the present work, the possibility of using #gamma# and X electromagnetic radiations to sterilize a Brazilian medicinal plant (Maytenus aquifolium Martius, Celastraceae), which shows anti-ulcer ...
Perforated thermoplastic masks are used to provide patients immobilization. This procedure inserts a material in the path of the radiation beam, that attenuates and modifies the beam fluence and flatness. The present study evaluates the increase in skin dose as a result of using thermoplastic masks. Relative doses were measured on the surface of a solid water phantom, in the presence and absence of masks. These masks were stretched according to deformation patterns observed in clinical routine. The measurements were obtained with a plane-parallel chamber (Markus type 23343) and radiochromic film (EBT Gafchromic) for 6MV X-rays from a linear accelerator, and for a radiation beam from a cobalt therapy unit. The results showed that thermoplastic masks, whose thickness varied between 2 and 3 mm, increased the dose on the surface by a factor of 3. Due to the variations in the skin dose distribution, clinical procedures were ...
Perforated thermoplastic masks are used to provide patients immobilization. This procedure inserts a material in the path of the radiation beam, that attenuates and modifies the beam fluence and flatness. The present study evaluates the increase in skin dose as a result of using thermoplastic masks. Relative doses were measured on the surface of a solid water phantom, in the presence and absence of masks. These masks were stretched according to deformation patterns observed in clinical routine. The measurements were obtained with a plane-parallel chamber (Markus type 23343) and radiochromic film (EBT Gafchromic) for 6MV X-rays from a linear accelerator, and for a radiation beam from a cobalt therapy unit. The results showed that thermoplastic masks, whose thickness varied between 2 and 3 mm, increased the dose on the surface by a factor of 3. Due to the variations in the skin dose distribution, clinical procedures were ...
Beams may be viewed as directed and focussed flow of energy and information, carried by particles and electromagnetic radiation fields (ie, photons). Often, they interact with each other (eg, in high energy colliders) or with other forms of matter (eg, in fixed targets, sychrotron radiation, neutron scattering, laser chemistry/physics, medical therapy, etc.). The whole art and science of beams revolve around the fundamental quest for, and ultimate implementation of, mechanisms of production, storage, control and observation of beams -- always directed towards studies of the basic structures and processes of the natural world and various practical applications. Tremendous progress has been made in all aspects of beam physics and technology in the last decades -- nonlinear dynamics, superconducting magnets and rf cavities, beam instrumentation and control, novel concepts and collider praradigms, to name a few. We illustrate ...
Accurate dose calculation in radiation treatment planning is most important for successful treatment. Since human body is composed of various materials and not an ideal shape, it is not easy to calculate the accurate effective dose in the patients. Many methods have been proposed to solve inhomogeneity and surface contour problems. Monte Carlo simulations are regarded as the most accurate method, but it is not appropriate for routine planning because it takes so much time. Pencil beam kernel based convolution/superposition methods were also proposed to correct those effects. Nowadays, many commercial treatment planning systems have adopted this algorithm as a dose calculation engine. The purpose of this study is to verify the accuracy of the dose calculated from pencil beam kernel based treatment planning system comparing to Monte Carlo simulations and measurements especially in inhomogeneous region. Home-made inhomogeneous phantom, Helax-TMS ver. 6.0 and Monte ...
Purpose: The aim of this study was to assess interinstitutional variations in planning for stereotactic body radiationtherapy (SBRT) for lung cancer before the start of the Japan Clinical Oncology Group (JCOG) 0403 trial. Methods and Materials: Eleven institutions created virtual plans for four cases of solitary lung cancer. The created plans should satisfy the target definitions and the dose constraints for the JCOG 0403 protocol. Results: FOCUS/XiO (CMS) was used in six institutions, Eclipse (Varian) in 3, Cadplan (Varian) in one, and Pinnacle3 (Philips/ADAC) in one. Dose calculation algorithms of Clarkson with effective path length correction and superposition were used in FOCUS/XiO; pencil beam convolution with Batho power law correction was used in Eclipse and Cadplan; and collapsed cone convolution superposition was used in Pinnacle3. For the target volumes, the overall coefficient of variation was 16.6%, and the interinstitutional ...
Background and purpose: the recent RTOG guidelines for future clinical developments in gynecologic malignancies included the investigation of dose escalation in the paraaortic (PO) region which is, however, very difficult to target due to the presence of critical organs such as kidneys, liver, spinal cord, and digestive structures. The aim of this study was to investigate intensity-modulated radiotherapy's (IMRT) possibilities of either increasing, in a safe way, the dose to 50-60 Gy in case of macroscopic disease or decreasing the dose to organs at risk (OR) when treatment is given in an adjuvant setting. Material and methods: the dosimetric charts of 14 patients irradiated to the PO region at the department of radiation oncology, university hospital of Liege, Belgium, in 2000 were analyzed in order to compare six-field conformal external-beam radio-therapy (CEBR) and five-beam IMRT approaches. Both CEBR and IMRT investigations were planned to ...
Hepatocellular carcinoma (HCC) is the most common primary liver cancer and has very limited therapeutic options. Recently, it has been found that hyaluronic acid (HA) shows selective binding to CD44 receptors expressed in most cancer histotypes. Since the trend in cancer treatment is the use of targeted radionuclide therapy, the aim of this research was to label HA with rhenium-188 and to evaluate its potential use as a hepatocarcinoma therapeutic radiopharmaceutical. Methods: {sup 188}Re-HA was prepared by a direct labelling method to produce a ReO(O-COO){sub 2}-type coordination complex. {sup 188}Re-HA protein binding and its stability in saline, phosphate buffer, human serum and cysteine solutions were determined. Biokinetic and dosimetric data were estimated in healthy mice (n=60) using the Medical Internal Radiation Dose methodology and mouse model beta-absorbed fractions. To evaluate liver toxicity, alanine aminotranferase (AST) and ...
One rationale proposals to increase the efficiency of PDT is to combine photo-sensitization with other treatment modalities, including modulation of arachidonic acid metabolism. In combine treatment we examined the effects of 48 h and 24 h pre-treatment of cells with 5- lipoxygenase inhibitor MK-886 prior to photoactivation of hypericin on cell cycle distribution and DNA synthesis. All parameters were examined 24 hours after hypericin activation. Pre-treatment of HT-29 with 5-lipoxygenase inhibitor MK-886 followed by PDT resulted in most significant effects on cell cycle perturbations. Administration of MK-886 alone as well as combination of low doses MK-886 with hypericin induced S phase accumulation. Increasing of MK-886 concentration induced massive changes in the cell cycle progression. Pre-treatment of HT-29 cells with MK-886 alone (15 #mu#M; - 48 h) caused accumulation of cells in S-phase (58 % in S-phase and 36 % in ...
BackgroundTransarterial chemoembolization (TACE) therapy is an effective locoregional treatment in hepatocellular cancer (HCC) patients. For early modification of therapy, markers...Full Text Available
The importance of intact host defense mechanisms for successful antimicrobial therapy was investigated in an animal model. Recovery from lobar pneumococcal pneumonia as a result of penicillin therapy...Full Text Available
Radionuclide bone metastases therapy is a major achievement of nuclear medicine. Development of less radiotoxic and more effective radiopharmaceuticals is therefore a challenge for radiopharmacists and industry. This paper reviews the application of rhenium-188 HEDP as a reactor- or generator-produced nuclide for bone metastases therapy. (author)
The current therapy for extrinsic and intrinsic asthma, together with that of ‘wheezing bronchitis’, is presented, with special attention to bronchodilators and adrenocorticosteroids....Full Text Available
The eye is an easily accessible, highly compartmentalised and immune-privileged organ that offers unique advantages as a gene therapy target. Significant advancements have been made in understanding...Full Text Available
PurposeTo determine the dosimetric impact of inter-fraction anatomical movements in prostate cancer patients receiving proton therapy.Full Text Available
1 Recommendations for correct therapy with digoxin from twenty-five sources are reviewed. 2 Some recommendations may be unsuitable for use with high bioavailability...Full Text Available
HT-29 human colon tumor cells growing as spheroids have been evaluated as a model system for measuring the response of human colon tumor cell to antineoplastic agents. HT-29 cells have been capacity to form spheroids up to 1 mm or more in diameter when grown in spinner culture. The multicellular HT-29 spheroids develop hypoxic centers reflecting the cellular conditions found in human cancer treatment, i.e., nutritionally deficient hypoxic cells that are felt to be a significant source of both radiation and chemotherapy clinical treatment failures. Spheroids of increasing size were radiated and then dispersed into single cells for colony survival assay. Compared with irradiated single cell suspensions, the spheroid cells demonstrated a significant increase in radioresistance. Growing spheroids developed a complex radiation survival curve which was variable with respect to size of the spheroid. The drug 5-Fu was studied to ...
Purpose: To determine if involved field radiation (IF) is equivalent to standard whole bone radiation (SF) in local tumor control; to establish patterns of failure following treatment; and to determine response, event-free survival (EFS), and overall survival rates from multidisciplinary therapy in Ewing's sarcoma. Methods and Materials: Between 1983 and 1988, 184 children with Ewing's sarcoma were enrolled onto Pediatric Oncology Group 8346 (POG 8346). A total of 178 (97%) met eligibility criteria; 6 had pathology other than Ewing's sarcoma. Induction chemotherapy of cyclophosphamide/doxorubicin (adriamycin )(C/A) x 12 weeks was followed by local treatment either surgery or radiationtherapy and C/A, dactinomycin, and vincristine for 50 weeks. Resection was advised for patients with small primary tumors if accomplished without functional loss. Forty patients were randomized to ...
This study is an attempt to measure the quantities of elements in a composite by irradiating that composite with #gamma#-rays of various energies and detecting the transmitted radiation through the composite. A previous knowledge of the number of the elements and their attenuation coefficients is required. The quantities are calculated by solving the matrix of a linear system of equations. A computer program was developed to select the best combinations of the available energies. Five criteria were established to determine these energy combinations: (i) the determinant of the attenuation coefficient matrix; (ii) the condition number, (iii) the number of times the solution of the matrix leads to acceptable results; (iv) the indicator, (a new concept); (v) the standard deviations of the results. The intended application of this technique in medicine is to measure the bone mineral content of the skeleton. An examination of the ...
The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest...
Twenty-two patients with vertebral primaries were registered in the Intergroup Ewing's Sarcoma Study between 1973 and 1977. The radiation doses to the primary tumors ranged between 3800 and 6200 rad. All patients received intensive combination chemotherapy. After a followup ranging between 14 and 62 months, 14 patients remained disease-free. All patients with primary tumor of the cervical and dorsal spine remained disease-free. Of eight patients with lesions in the distal spine, (sacrococcygeal region) six developed recurrence, in three a local recurrence was observed despite doses of 6000 rad or higher. Doses of 5000 rad or less (in addition to combination chemotherapy as used in the Intergroup Ewing's Study) appear adequate in controlling the primary tumors of the proximal segments of the spinal column.
By measuring organ doses with TLD at an Alderson-Rando-phantom it was tested to evaluate the somatic risk for mammographies. Similarly as the genetic risk can be expressed by the genetic significant dose, the somatic risk can be expressed by the somatic significant dose index. The measurement results of the mammography show a large deviation of almost one power of ten with dependence of the chosen technique. In conventional xeroradiography and recording technique with foilless film the somatic radiation risk is the highest. By using amplifying foils in combination with high-sensitive films it is relatively small. Unfortunately the magnitude of the somatic risk in the different mammography techniques is in the ratio reciprocal to the corresponding image quality. At the time being the most favourable technique is mammography with a soft rastering method, although the xeromammography with additional high aluminium-filtering is a further ...
Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85"0C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to #gamma#-rays. A thin aluminium foil was used to cover the inner wall of the reaction vessel so that the extent of homo polymer could be reduced to be less than 1.6% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmations of graft copolymerization and saponification reactions were made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the same total dose on the extent of grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.
Abstract A miniaturized spatial temperature gradient CE system with automated sample introduction for DNA mutation detection was established. Continuous electrokinetic sample injection was achieved by combining an automated slotted vial array sample introduction device to the spatial temperature gradient CE system. The temperature gradient was produced by a radiative heating system with a single graphite block heater, and the stability of the temperature gradient was investigated. The temperature variation of each measure point was 0.12 0.21% RSD (n=7) within 6 h. A 14 cm Teflon AF coated silica capillary was used both as the separation channel and as the liquid core waveguide tube of fluorescence signal. Under a temperature gradient from 54.8 to 59.5 C, a low range control mutation standa...
An evaporative cooling system developed for operation and qualification testing of silicon pixel and microstrip detectors for the inner tracking detector of the CERN ATLAS spectrometer is described. Silicon detector substrates must be continuously operated between 0 and ???7?C in the high radiation environment near the circulating beams at the CERN Large Hadron Collider (LHC). This requirement imposes unusual constraints on the cooling system and has led to the choice of perfluoro-n-propane (C3F8) refrigerant, which combines good chemical stability under ionizing radiation with high dielectric strength and nonflammability. Since the silicon detectors must also be of extremely light construction to minimize undesirable physics background, coolant tubes are of thin (200 ?m) aluminum wall, wh...
Radiation-and-thermal-combined degradation of ethylene-propylene rubber (EP rubber) and chlorosulfonated polyethylene (CSM) as cable insulating and jacketing materials were evaluated by accelerated aging tests and a method to assess the lifetime of these materials under practical application was studied. EP rubber and CSM of experimental formulation were degraded at accelerated rates, that are 50 [approx] 1000 times the degradation rate under a standard condition (1Gy/h, 50degC). The degradation was investigated by measuring the tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for both EP rubber and CSM were in proportion to increase in accelerated rate. Behaviors of elongation changes showed little difference with accelerated rate. EP rubber lifetime estimated from sequential aging test had a tendency to extend beyond that from simultaneous aging test, while CSM lifetime estimated from both aging tests were ...
Radiation-and-thermal-combined degradation of ethylene-propylene rubber (EP rubber) and chlorosulfonated polyethylene (CSM) as cable insulating and jacketing materials were evaluated by accelerated aging tests and a method to assess the lifetime of these materials under practical application was studied. EP rubber and CSM of experimental formulation were degraded at accelerated rates, that are 50 #approx# 1000 times the degradation rate under a standard condition (1Gy/h, 50degC). The degradation was investigated by measuring the tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for both EP rubber and CSM were in proportion to increase in accelerated rate. Behaviors of elongation changes showed little difference with accelerated rate. EP rubber lifetime estimated from sequential aging test had a tendency to extend beyond that from simultaneous aging test, while CSM lifetime estimated from both aging tests were ...
An essential part of fire risk assessment is the analysis of fire hazards and fire propagation. In this work, models and tools for two different aspects of numerical fire simulation have been developed. The primary objectives have been firstly to investigate the possibility of exploiting state-of-the-art fire models within probabilistic fire risk assessments and secondly to develop a computationally efficient solver of thermal radiation for the Fire Dynamics Simulator (FDS) code. In the first part of the work, an engineering tool for probabilistic fire risk assessment has been developed. The tool can be used to perform Monte Carlo simulations of fires and is called the Probabilistic Fire Simulator (PFS). In Monte Carlo simulation, the simulations are repeated multiple times, covering the whole range of variability of the input parameters and thus resulting in a distribution of results covering what can be expected in reality. In practical applications, advanced ...
A key comparison has been made between the air-kerma standards of the ARPANSA and the BIPM in the low-energy X-ray range. The results show the standards to be in agreement at the level of the combined standard uncertainty of 7.0 parts in 10"3 for the 10 kV radiation quality and 3.7 parts in 10"3 for all other beam qualities. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. (authors)
Focusing and resonance properties of two-dimensional small-size hemielliptic lenses made of different materials are studied numerically in order to estimate the influence of internal reflections on the radiation characteristics of dielectric lens antennas. Accuracy of in-house made algorithms based on combination of geometrical and physical optics and FDTD in the analysis of optical and modal effects in the behavior of such lenses is tested by comparison with the exact solution obtained using the Muller boundary integral equations. The range of applicability for the approaches is discussed.
The results of treatment of 134 cases of morphologically-verified localized Ewing's sarcoma were evaluated. A comparative analysis showed relapse-free survival to be significantly lower for radiation treatment (23 %) than for its combination with various cytostatic drugs. Two-year relapse-free survival rate was as high as 43 % in cases receiving sarcolysin or cyclophosphamide as adjuvants. This was matched by 47 % for adjuvant ardiamycin or carminomycin and 56 % for adriamycin plus cyclophosphamide and vincristine. Evaluation of long-term results of adjuvant chemotherapy showed sex, age and site involvement to be of certain prognostic value.
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 ...
The contribution of US, CT and MR imaging was investigated in 25 cirrhotic patients with hepatocellular carcinoma. The following parameters were considered: lesion detection, site and size of the lesion, daughter nodules, location and/or infiltration of intrahepatic vessels, patency of portal vein and collateral vessels, signs of chronic liver disease, steatosis, ascitis, and lymphadenopathy. The results confirm the value of US, which also allowed lesion biopsy in all cases. CT was as accurate as US in detecting the lesion and even superior in demonstranting daughter nodules. MR imaging, with conventional SE and IR sequences, was inferior since it missed 3 lesions due to motion artifacts; more over, a smaller number of daughter nodules was seen than with CT. The authors conclude that, at present, MR imaging cannot replace US and CT; the latter, if combined with artheriography, using either hidrosoluble or liposoluble contrast agents, gives the best results in the ...
Current antidotal regimens for organophosphorus compound (OP) poisoning consist of a combination of pretreatment with a spontaneously reactivating AChE inhibitor such as pyridostigmine bromide, and postexposure therapy with anticholinergic drugs such as atropine sulfate and oximes such as 2-PAM chloride (Gray, 1984). Although these antidotal regimens are effective in preventing lethality of animals from OP poisoning, they do not prevent postexposure incapacitation, convulsions, performance deficits, or, in many cases, permanent brain damage (Dunn and Sidell, 1989). These problems stimulated the development of enzyme bioscavengers as a pretreatment to sequester highly toxic OPs before they reach their physiological targets. Several studies over the last two decades have demonstrated that exogenously administered human serum butyrylcholinesterase (Hu BChE) can be used successfully as a safe, efficacious, and single prophylactic treatment to ...
Radiotherapy can be very significant as the treatment for ocular lesions, eyes need to be preserved as properly as possible on their functions and cosmetics. The application of conventional X ray therapy has been gradually abandoned as conventional X ray therapy ceased to be accepted as the general treatment for malignant tumors. Consequently the necessity of electron beam therapy has been rising even as the substituted method for conventional X ray therapy. The department of radiology of Gunma University was obliged to establish a new therapy for ocular lesions, and has been trying electron beam therapy since 1973. It is concluded that electron beam therapy is not at all inferior to conventional X ray therapy as reported above. Basic therapeutic methods for ocular lesions are the following: 1) For epidermoid carcinoma, ...
Dose calculations for radiation arc therapy are traditionally performed by approximating continuous delivery arcs with multiple static beams. For 3D conformal arc treatments, the shape and weight variation per degree is usually small enough to allow arcs to be approximated by static beams separated by 5"0-10"0. But with intensity-modulated arc therapy (IMAT), the variation in shape and dose per degree can be large enough to require a finer angular spacing. With the increase in the number of beams, a deterministic dose calculation method, such as collapsed-cone convolution/superposition, will require proportionally longer computational times, which may not be practical clinically. We propose to use a homegrown Monte Carlo kernel-superposition technique (MCKS) to compute doses for rotational delivery. The IMAT plans were generated with 36 static beams, which were subsequently interpolated into finer angular intervals for dose ...
In radiationtherapy with hadron beams, conformal irradiation to a tumour can be achieved by using the properties of incident ions such as the high dose concentration around the Bragg peak. For the effective utilization of such properties, it is necessary to evaluate the volume irradiated with hadron beams and the deposited dose distribution in a patient's body. Several methods have been proposed for this purpose, one of which uses the positron emitters generated through fragmentation reactions between incident ions and target nuclei. In the previous paper, we showed that the maximum likelihood estimation (MLE) method could be applicable to the estimation of beam end-point from the measured positron emitting activity distribution for mono-energetic beam irradiations. In a practical treatment, a spread-out Bragg peak (SOBP) beam is used to achieve a uniform biological dose distribution in the whole target volume. Therefore, in the ...
The serum levels of ferritin in 394 patients, including 339 patients with various malignant tumors and 23 with various non-malignant diseases, and 32 healthy subjects were determined. The normal levels of ferritin were 82.7 +- 42.3 ng/ml for males and 42.0 +- 36.9 ng/ml for females. The positive ratio of serum ferritin level was 28% in patients with malignant tumors and 22% in patients with non-malignant diseases. The usefulness of serum ferritin assay in screening for malignant tumors appeared to be limited. High serum levels of ferritin were found in patients with malignant lymphoma (positive ratio: 42%), pulmonary cancer (38%) and esophageal cancer (37%). According to the histological types, epidermoid cancer appeared to produce a higher serum level of ferritin than adenocarcinoma in patients with pulmonary cancer. It was interesting that malignant lymphoma had a high serum level of ferritin in spite of its low serum level of CEA. Carcinoma of the digestive tracts except for ...
The combination of functional and morphological imaging technologies such as positron emission tomography (PET) and X-ray computed tomography (CT) has shown its value in the clinical and preclinical field. However, CT provides only very limited soft-tissue contrast and exposes the examined patient or laboratory animal to a high X-ray radiation dose. In comparison to CT, magnetic resonance tomography (MRI) provides excellent soft-tissue contrast and allows for nuclear magnetic resonance spectroscopy (NMRS) or functional MRI (fMRI). Thus, the combination of PET and MRI has been pursued for several years. First approaches have succeeded using conventional photo multiplier tube (PMT) technology together with light fibers to transfer scintillation light away from the high magnetic field. Latest PET/MRI developments use solid-state light detectors that can be operated even at high magnetic fields. Initial pilot studies with ...
Stereotactic radiosurgery (SRS) precisely delivers high-dose radiation to a small target (usually less than 3-4 cm in diameter), in a single session with steep dose-fall, employing various radiation methods. SRS provides good tumor control for small brain metastases from various primary cancers, with minimal untoward effects on surrounding normal brain. This excellent tumor control prevents neurological death and maintains good activity of daily life. Although surgery with whole-brain radiationtherapy (WBRT) remains an important option for patients with a solitary brain metastasis, SRS with or without WBRT should be considered in patients with a limited number of small tumors and a good prognosis. Many reports, as well as both retrospective and prospective reviews, have shown WBRT before or after SRS to improve local control and reduce new distant lesion emergence. However, upfront WBRT does not ...
Radiation-induced enteritis is a well-recognized sequel of therapeutic irradiation. Therefore we examined the radioprotective properties of Punica granatum peel extract (PPE) on the oxidative damage in the ileum. Rats were exposed to a single whole-body X-ray irradiation of 800 cGy. Irradiated rats were pretreated orally with saline or PPE (50 mg/kg/day) for 10 days before irradiation and the following 10 days, while control rats received saline or PPE but no irradiation. Then plasma and ileum samples were obtained. Irradiation caused a decrease in glutathione and total antioxidant capacity, which was accompanied by increases in malondialdehyde levels, myeloperoxidase activity, collagen content of the tissue with a concomitant increase 8-hydroxy-2'-deoxyguanosine (an index of oxidative DNA damage). Similarly, pro-inflammatory cytokines (TNF-?, IL-1? and IL-6) and lactate dehydrogenase were elevated in irradiated groups as compared to control. PPE treatment reversed ...
Efforts to assess and quantify deleterious effects from toxicants concentrate mainly on single agents whereas real world environmental and occupational exposures to natural and anthropogenic agents entail quite often the concomitant presence of several toxicants. For occupational important exposure situations, combined exposures to physical and chemical agents such as radon and smoking or asbestos and smoking, respectively, were shown to produce over-additive effects at exposure levels typical for earlier workplaces. Already the elucidation of possible health risks from a single agents, its dependence on exposure level, exposure rates, age at exposure and its expression in time is a complex endeavour. Therefore in the past and the present the main emphasis in radiation protection, toxicology, and public health is on the study and assessment of single toxicants. The existing data base on combined effect is rudimentary, ...
The TESLA Test Facility (TTF) at DESY is a facility producing sub-picosecond electron pulses for the generation of VUV or soft X-ray radiation in a free electron laser (FEL). The same electron pulses would also allow the direct production of high-power coherent radiation by passing the electron beam through an undulator. Intense, coherent far-infrared (FIR) undulator radiation can be produced from electron bunches at wavelengths longer than or equal to the bunch length. The source described in this paper provides, in the wavelength range 50-300 #mu#m, a train of about 1-10 ps long radiation pulses, with about 1 mJ of optical energy per pulse radiated into the central cone. The average output power can exceed 50 W. In this conceptual design, we intend to use a conventional electromagnetic undulator with a 60 cm period length and a maximum field of 1.5 T. The FIR source will use the ...
Subject of this study is the question of whether cone beam CT (CBCT) images with reduced projection data are suitable for use in adaptive radiationtherapy (ART) treatment planning. For this purpose image quality and dose calculation accuracy depending on imaging modality were analysed. In this context, two CBCT-methods will be indicated having reduced projection data sets: Scans acquired with 200^o rotation angle in order to accelerate the CBCT process (half scan), or scans with an asymmetric cone beam and detector offset, used to enlarge the field-of-view (half fan). Methods: For three different CBCT-modes (On-Board-Imaging, Varian Medical Systems), two of them based on reduced projection data, and a conventional multidetector CT system, the main image quality parameters were studied. Tr...
The aim of this study was to evaluate the differences in accuracy of dose calculation between 3 commonly used algorithms, the Pencil Beam algorithm (PB), the Anisotropic Analytical Algorithm (AAA), and the Collapsed Cone Convolution Superposition (CCCS) for intensity-modulated radiationtherapy (IMRT). The 2D dose distributions obtained with the 3 algorithms were compared on each CT slice pixel by pixel, using the MATLAB code (The MathWorks, Natick, MA) and the agreement was assessed with the ? function. The effect of the differences on dose-volume histograms (DVHs), tumor control, and normal tissue complication probability (TCP and NTCP) were also evaluated, and its significance was quantified by using a nonparametric test. In general PB generates regions of over-dosage both in the lung and in the tumor area. These differences are not always in DVH of the lung, although the Wilcoxon test indicated significant differences in 2 of 4 patients. ...
A book has been written to introduce the physical aspects of the radiotherapy electron beam by presenting a summary of the developments in this field. The first chapter is a brief introduction to the technology of medical accelerators with emphasis on the electron beam production facilities. Chapter 2 describes the interaction processes at the atomic level once the electron beam enters the medium. Chapter 3 is concerned with the various properties of the electron beam purely from the clinical point of view. The electron beam algorithms and models for distribution calculations are covered in Chapter 4 with inclusion of age diffusion and multiple scattering approaches. The factors affecting the beam distribution in a patient, with inhomogeneities, surface irregularities, backscattering etc. are discussed in Chapter 5. The last two chapters are devoted to electron beam dosimetry including various dosimetric methods, specification and measurement of beam energy, ...
The purpose of this study was to determine the optimal technique for delivering postoperative radiotherapy for vulvar cancer and other tumors requiring treatment of the inguinal nodes. This project compared tumor coverage and normal tissue sparing for the 5 main radiotherapy techniques that are used to treat vulvar cancer. The intensity-modulated radiationtherapy (IMRT) plan was undesirable because it resulted in an excessive dose to portions of the central pelvic structures. The photon thunderbird with skin match was unacceptable because it underdosed a portion of the groin region. The electron thunderbird was ideal for thin patients but was not applicable for most patients because of excessive dose to the skin and subcutaneous tissues. The photon through-and-through and the photon thunderbird with deep match were acceptable in most situations. In thin patients, where the depth of the inguinal vessels is less than 3 cm, the electron ...
The aim of this study was to evaluate the radioprotective effect of turmeric extract (40 mg/kg body weight) and vitamin E (#alpha# - tocopherol acetate, 400 IU/kg body weight) supplementation on lipid peroxidation, reduced glutathione and antioxidant defense enzymes in various organs like liver, kidney and salivary glands at 24 h in adult Swiss mice. "1"3"1Iodine exposure significantly increased lipid peroxidation in kidney and salivary glands in comparison to control animals. Pre supplementation with turmeric extract for 15 days showed significant lowering of lipid peroxidation in kidney. On the other hand vitamin E pre supplementation showed marked reduction in lipid peroxidation in salivary glands. Reduced glutathione levels decreased significantly in liver after radiation exposure. However, pre supplementation with turmeric extract and vitamin E did not improve glutathione levels in liver. In conclusion we have observed differential radioprotective effect of ...
A method has been developed for calibration of CT-numbers to volumetric electron density distributions using tissue substitutes of known elemental composition and experimentally determined electron density. This information have been used in a dose calculation method based on photon and electron interaction processes. The method utilizes a convolution integral between the photon fluence matrix and dose distribution kernels. Inhomogeneous media are accounted for using the theorems of Fano and O'Connor for scaling dose distribution kernels in proportion to electron density. For clinical application of a calculated dose plan, a method for prediction of accelerator output have been developed. The methods gives the number of monitor units that has to be given to obtain a certain absorbed dose to a point inside an irregular, inhomogeneous object. The method for verification of dose distributions outlined in this study makes it possible to exclude the treatment related variance contributions, ...
As yet, the role of Computed Tomography (CT) as a routine imaging technique in the staging and follow-up of thoracic Hodgkin's disease has not been assessed. The authors reported the results obtained in 120 patients affected with thoracic Hodgkin's disease, staged and followed by means af chest X-rays and CT. CT better identified intrathoracic involvement of mediastinal nodes, of lung parenchyma, of pleura, and of pericarcial and chest walls in 54/120 patients (45%), with staging modifications in 18 (15%) of them only. Treatment was changed only in 12 patients (19%) where radiationtherapy had been planned. The clinical value of the additional information yielded by CT was especially evident in the follow-up: CT allowed the correct evaluation of persistent/ recurrent disease in 51/117 patients (43.5%), a figure high enough to suggest the use of CT in the routive follow-up of patients affected with thoracic Hodgkin's disease.
In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable for routine work. In computed radiography, image processing (tone scale modification and edge enhancement) is possible, and is advantageous portal imaging. When PACS is introduced to the ...
In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable for routine work. In computed radiography, image processing (tone scale modification and edge enhancement) is possible, and is advantageous portal imaging. When PACS is introduced to the ...
The unsteady state heat transfer behaviour of a vertical wall subject to the effects of uniform radiation is investigated and the dimensional analysis of combined heat transfers by conduction, convection and radiation is presented. The convective heat transfer coefficients used in the numerical model are determined experimentally by means of an assembly resembling the conditions encountered in the dwelling (variable temperatures and heat flows in time and space, wall associated with a floor, radiative flux outside the wall). In routine conditions (homogeneous wall dimensions, temperature differentials less than 40/sup 0/C), it is shown that the problem depends in practice on three parameters (instead of five) and that nomographs can give the energy accumulated in the wall as a function of its geometric and thermal charactersitics and the external conditions (type and thickness of material, changes in ...
We developed a new TLD array for precise dose measurement and verification of the spatial dose distribution in small radiation targets. It consists of a hemicylindrical, tissue-equivalent rod made of polystyrene with 17 parallel moulds for an exact positioning of each TLD. The spatial resolution of the TLD array was evaluated using the Leskell spherical phantom. Dose planning was performed with KULA 4.4 under stereotactic conditions on axial CT images. In the Leksell gamma unit the TLD array was irradiated with a maximal dose of 10 Gy with an unplugged 14 mm collimator. The doses delivered to the TLDs were rechecked by diode detector and film dosimetry and compared to the computer-generated dose profile. We found excellent agreement of our measured values, even at the critical penumbra decline. For the 14 mm and 18 mm collimator and for the 11 mm collimator combination we compared the measured and calculated data at full width at half maximum. ...
Purpose Radiation-induced heart disease (RIHD) is a severe side effect of thoracic radiotherapy. This study examined the effects of pentoxifylline (PTX) and a-tocopherol on cardiac injury in a rat model of RIHD. Methods and Materials Male Sprague-Dawley rats received fractionated local heart irradiation with a daily dose of 9 Gy for 5 days and were observed for 6 months after irradiation. Rats were treated with a combination of PTX, 100 mg/kg/day, and a-tocopherol (20 IU/kg/day) and received these compounds either from 1 week before until 6 months after irradiation or starting 3 months after irradiation, a time point at which histopathologic changes become apparent in our model of RIHD. Results Radiation-induced increases in left ventricular diastolic pressure (in mm Hg: 35 +- 6 after sham...
A brief comparative review of possible mercury free fluorescent lighting technologies is presented, including rare-gas positive column discharges, molecular discharges, and dielectric barrier discharges. Detailed experimental results on xenon positive column discharges will then be considered. In order to judge whether xenon-based discharges are a viable UV source it is necessary to measure the radiant emittance (power per unit area) for the vacuum ultraviolet (VUV) resonance xenon emission at 147 nm. Two techniques to determine the VUV radiant emittance have been developed and applied to xenon discharges. One method combines the measured resonance level density using absorption spectroscopy and a calculation of the trapped decay rate for the resonance radiation to arrive at the radiant emittance at 147 nm. A second method utilizes a direct measurement of the radiance (power per unit area per unit solid angle) at 147 nm using a calibrated VUV ...
The O({alpha}) electroweak radiative corrections to {gamma}{gamma}{yields}WW{yields}4f within the electroweak standard model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into factorizable and non-factorizable contributions, and real-photonic corrections are based on complete lowest-order matrix elements for {gamma}{gamma}{yields}4f+{gamma}. Soft and collinear singularities appearing in the virtual and real corrections are combined alternatively in two different ways, namely by using the dipole subtraction method or by applying phase-space slicing. The radiative corrections are implemented in a Monte Carlo generator called Coffer {gamma}{gamma} - the computer code can be obtained from the authors upon request - which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over realistic spectra of ...
The O(#alpha#) electroweak radiative corrections to #gamma##gamma##->#WW#->#4f within the electroweak standard model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into factorizable and non-factorizable contributions, and real-photonic corrections are based on complete lowest-order matrix elements for #gamma##gamma##->#4f+#gamma#. Soft and collinear singularities appearing in the virtual and real corrections are combined alternatively in two different ways, namely by using the dipole subtraction method or by applying phase-space slicing. The radiative corrections are implemented in a Monte Carlo generator called Coffer #gamma##gamma# - the computer code can be obtained from the authors upon request - which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over realistic spectra of the ...
Large-scale field tracer experiments have been conducted on Ulchin and Wolsung nuclear sites for the purpose of validating FADAS and of analyzing the environmental characteristics around the nuclear site. The most influential factor in atmospheric dispersion is the meteorological condition. During the experiment, meteorological data were measured on the release point and the selected positions among sampling points. Once radioactive materials are released to the atmosphere, members of public may be exposed through the environmental media such as air, soil and foods. Therefore, to protect the public, adequate countermeasures should be taken at due time for those exposure pathways. Both processes of justification and optimization are applied to a countermeasure simultaneously for decision-making. The work scope of biological research for the radiation protection had contained the search of biological microanalytic methods for the assessment of health effect by ...
Primary malignant lymphoma of the brain is a disease of unknown etiology, which is increasing in incidence and has an unfavorable prognosis. Despite the lack of specific changes on CT or MRI in most cases, these procedures may typically facilitate the diagnosis: A focal-enhancing mass with subependymal spread on CT or MRI and hyperattenuation on nonenhanced CT are the most reliable features in the diagnosis of primary malignant lymphoma of the brain. Peritumoral edema and mass effect are usually not prominent features. On unenhanced CT scans they usually appear homogeneously isodense to mildly hyperdense relative to the gray matter. On MRI these tumors are slightly hypointense on T1-weighted images and slightly hpyerintense on PD- and T2-weighted images relative to the gray matter. On CT and MRI enhancement is usually homogeneous. Contrast-enhanced MRI, with its multiplanar capability, lack of bone-induced artifacts, and high-contrast resolution, is likely to reveal subependymal spread ...
Background and purpose: the recent RTOG guidelines for future clinical developments in gynecologic malignancies included the investigation of dose escalation in the paraaortic (PO) region which is, however, very difficult to target due to the presence of critical organs such as kidneys, liver, spinal cord, and digestive structures. The aim of this study was to investigate intensity-modulated radiotherapy's (IMRT) possibilities of either increasing, in a safe way, the dose to 50-60 Gy in case of macroscopic disease or decreasing the dose to organs at risk (OR) when treatment is given in an adjuvant setting. Material and methods: the dosimetric charts of 14 patients irradiated to the PO region at the department of radiation oncology, university hospital of Liege, Belgium, in 2000 were analyzed in order to compare six-field conformal external-beam radio-therapy (CEBR) and five-beam IMRT approaches. Both CEBR and IMRT investigations were ...
Background. In multiple myeloma 5 different infiltration patterns can be differentiated: 1. Normal appearance of bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. 'salt-and pepper' pattern with inhomogeneous bone marrow with interposition of fat islands. Methods. For the fast and total acquisition of all patterns a combination of a T1-weighted spin echo sequence and a fat suppression technique is superior. The focal involvement is clearly demonstrated as areas of high signal intensity on e.g. STIR images. Diffuse involvement can be quantified objectively by calculation of the percentage of signal intensity increase after contrast material injection. MRI is superior to X-ray in focal and diffuse involvement. With ultrafast sequences a 'screening' of the whole red bone marrow as for myeloma infiltration is possible. Prognosis. In prognosis ...
We investigated the efficacy of combined FDG-PET/CT imaging for the diagnosis of small-size uveal melanomas and the feasibility of combining separate, high-resolution (HR) FDG-PET with MRI for its improved localization and detection. Patients, methods: 3 patients with small-size uveal melanomas (0.2-1.5 ml) were imaged on a combined whole-body PET/CT, a HR brain-PET, and a 1.5 T MRI. Static, contrast-enhanced FDG-PET/CT imaging was performed of head and torso with CT contrast enhancement. HR PET imaging was performed in dynamic mode 0-180 min post-injection of FDG. MRI imaging was performed using a high-resolution small-loop-coil placed over the eye in question with T2-3D-TSE and T1-3D-SE with 18 ml Gd-contrast. Patients had their eyes shaded during the scans. Lesion visibility on high-resolution FDGPET images was graded for confidence: 1: none, 2: suggestive, 3: clear. Mean tumour activity was calculated for summed image ...
Feasibility of using combined release of sterile males and sterile females for population suppression of Earias vittella (Fabricius) was evaluated on okra in two ways. In one study, a combined release of sterile males and sterile females was evaluated under simulated conditions in laboratory, a 10: 10: 1: 1 (sterile male: sterile female: normal female: normal male) ratio effected > 99% sterility. In the second study, in a field cage experiment, a combined release of sterile males and sterile females was evaluated using normal males and tethered normal females. In this experiment, the release of sterile males and sterile females in 10: 10: 1: 1 ratio caused complete 'shut off' of mating of normal females for first 2 days and indicated>93% reduction in the larval progeny in the next generation. The tethered females were allowed to mate only once. E. vittella females mate multiply and so with overwhelming numbers of ...
This short survey focuses on the main radiation-induced base lesions that have been identified within cellular DNA. For this purpose, sensitive assays that are aimed at measuring a few modifications per 10{sup 7} normal bases were set-up. In that respect high performance liquid chromatography - tandem mass spectrometry (CLHP-MS/MS) was found to be able to single out the formation of 9 oxidized nucleosides and two modified nucleo-bases out of the 70 oxidative base lesions that have been identified in model systems. As a striking result, it was found that in the DNA of {gamma}-irradiated human monocytes, the formamide-pyrimidine derivative of guanine is produced in a higher yield than the ubiquitous 8-oxo-7,8-dihydro-guanine damage, both arising from the same radical precursor. However, relatively high doses of ionizing radiation (> 20 Gy) have to be applied in order to detect an increase in the level of the damage. This is due to the low ...
An embodiment of a mercury-free fluorescent lamp combines a low pressure rare gas discharges with a phosphor having a quantum efficiency grater than one. The choice of the rare gas depends on a number of factors, one of which is the resonance transition energy. Less demand is placed the quantum efficiency of the phosphor for a lower energy resonance photon. Xenon has the lowest energy resonance transition of the stable rare gases at 8.5 eV (147 nm) and thus is a good candidate to study. The usefulness of a xenon-based discharge depends on the radiant emittance of the discharge at the resonance wavelength of 147 nm. The radiant emittance from a low pressure xenon positive column discharge is measured using two independent techniques. The first relies on the measurement of the resonance level density using absorption techniques. The effective decay rate of the resonance level is calculated using radiation trapping theory. The product of this ...
Microcapsules consisting of alginate and hyaluronic acid that can be decomposed by radiation are currently under development. In this study, the composition of the microcapsule material was optimized by changing the amounts of alginate and hyaluronic acid. Solutions of 0.025%, 0.05%, 0.1%, 0.2%, or 0.4% (wt./vol.) hyaluronic acid were mixed into a 0.2% alginate solution. To these mixtures, carboplatin (0.2 mmol) was added and the resulting material was used for the capsule preparation. The capsules were prepared by spraying the material into a CaCl{sub 2} solution (0.34 mol/l) using a microatomizer. These capsules were irradiated by a single dose of 2, 5, or 10 Gy {sup 60}Co {gamma}-ray radiation. Immediately after irradiation, the releasing of core content of microcapsule was determined, using a micro particle induced X-ray emission (PIXE) camera. The average diameter of the microcapsules was 22.3 {+-} 3.3 {mu}m, and that of the liquid core ...
Depletion of stratospheric ozone increases irradiance of terrestrial ultraviolet (UV) radiation at short wavelengths, which may be harmful to the human health. To understand quantitatively the risks caused by increasing UV radiation to the Finnish population, the actual UV exposure of the population has to be assessed. It was shown that the snow reflection increases the UV exposure to the face and eyes particularly in the northern Finland. In 1993 exceptionally low ozone levels persisted up to the end of May, which resulted in a theoretical increase in the annual UV dose ranging from 8 % to 13 % in Finland. The maximal increase in the measured erythemally effective dose rate was 34 % on 23 April, when compared with the theoretical normal value. During this study exposure models have been developed. The models have been combined them with Green`s radiation transfer model to estimate annual facial UV ...
The grafted human glioblastoma cell CB109 was used as a model for intralesional therapy with 131I-labelled hyaluronectin glycoprotein (131I-HN). 131I-HN bound specifically to in situ hyaluronic acid (HA), a main component of the extracellular matrix which is involved in tumour invasion. Labelling experimental conditions were determined and, finally, 25 {mu}Ci/{mu}gHN, 1 {mu}g chloramine-T/{mu}gHN and a 60-s stirring period provided a 131I-HN preparation with an optimal affinity for HA (64% compared to unlabelled HN). Following intratumoral injection, 131I-HN was retained with a limited diffusion outside the tumour. On day 4 the radioactivity concentrated in the tumour was still 25 times greater than that in the liver, spleen and kidneys combined. For therapeutic assays, 65 {mu}Ci 131I-HN was injected into the tumour, resulting in a delivery of 6.8 Gy over a 7-day period. Controls received unlabelled HN, heat-inactivated HN, a mixture of ...
PNAS-4, a novel pro-apoptotic gene activated during the early response to DNA damage, can inhibit proliferation via apoptosis when overexpressed in some tumor cells. Recent studies have indicated that honokiol can induce apoptosis, inhibit angiogenesis, and suppress tumor growth. In the present study, we investigated whether mouse PNAS-4 (mPNAS-4) could augment the apoptosis of tumor cells induced by honokiol in vitro, and whether the antiangiogenic activity of honokiol and induction of apoptosis by mPNAS-4 could work cooperatively to improve the antitumor efficacy in vivo. In vitro, mPNAS-4 inhibited proliferation of murine colorectal carcinoma CT26 and Lewis lung carcinoma LL2 cells through induction of apoptosis, and significantly augmented the apoptosis of CT26 and LL2 cells induced by honokiol. Compared with treatment with mPNAS-4 or honokiol alone, in vivo systemic administration of an expression plasmid encoding mPNAS-4 and low-dose honokiol significantly suppressed tumor growth ...
Background. In multiple myeloma 5 different infiltration patterns can be differentiated: 1. Normal appearance of bone marrow, 2. focal involvement, 3. homogeneous diffuse infiltration, 4. combined diffuse and focal infiltration, 5. 'salt-and pepper' pattern with inhomogeneous bone marrow with interposition of fat islands. Methods. For the fast and total acquisition of all patterns a combination of a T1-weighted spin echo sequence and a fat suppression technique is superior. The focal involvement is clearly demonstrated as areas of high signal intensity on e.g. STIR images. Diffuse involvement can be quantified objectively by calculation of the percentage of signal intensity increase after contrast material injection. MRI is superior to X-ray in focal and diffuse involvement. With ultrafast sequences a 'screening' of the whole red bone marrow as for myeloma infiltration is possible. Prognosis. In prognosis studies diffuse infiltration is ...
Nuclear radiation detectors in integral execution were produced by successive epitaxial growth from vapor phase of Zn Te and Cd Se thin layers onto scintillating Zn Se (Te) crystals. The irradiation of combined Zn Se (Te) - Zn Te - Cd Se detectors by Cu_K_a X-rays leads to the appearance of photoreceiver e.m.f., which tends to saturation with the increase of X-ray radiation dose reaching the value of 0.34-0.40 V at 200 R/min. The short circuit current dependence of irradiation dose power is linear. The matching factor for detectors with Zn Te-Cd Se photoreceivers with different doping levels is 0.68-0.92. The absolute monochromatic sensitivity is 0.32-0.35 m A/m W at a quantum efficiency 0.58-0.61 and a time constant 2 x 10"-"4 s. The calculated dose sensitivity for Zn Se(Te)-Zn Te-Cd Se combined detectors at the irradiation with X-rays having effective energy 8.86 keV gives the value 3.9 x 10"-"7 ...
Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/..gamma.. ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time ..gamma.. spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded ..gamma.. spectra created by the photopeak-Compton edge combination in the plateau portion of the knee response, correcting equations ...
Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/#gamma# ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time #gamma# spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded #gamma# spectra created by the photopeak-Compton edge combination in the plateau portion of the knee response, correcting equations using ...
Personnel radiation monitoring is essential to the operation of any nuclear facility and work in this area continues to strive for an accurate determination of personnel dose. In particular recent attention has been focused upon the need to improve the accuracy of neutron dosimetry, mainly because of their high Relative Biological Effectiveness. In this work the feasibility of using the NE-213 liquid scintillation detector as an efficient neutron/gamma ray radiation monitor is demonstrated. Derivative method spectrum unfolding used in MATXUF for on-line analysis of fast neutron spectra has also been applied to real time gamma spectrum unfolding (MATXUF2), making possible simultaneous on-line monitoring of both fast neutrons and gammas. To eliminate the negative fluxes in the unfolded gamma spectra created by the photopeak-compton edge combination in the plateau portion of the knee response, correcting equations using a ...
A number of procedures in diagnostic radiology and cardiology make use of long exposures to x-rays from fluoroscopy units. Although numerous studies have been performed to measure or calculate skin dose from these procedures, there have only been a handful of studies to determine the dose to the other organs. This thesis was focused on devising a method to calculate the absorbed dose to underlying tissues and organs. The work was performed in several stages. First, a commercial convolution/superposition-based treatment planning system used in radiation oncology was modified and complemented to make it usable with the low energies of x-rays used in diagnostic radiology. This required generation of energy deposition kernels in the kilovoltage energy range. The kernels were generated using the EGS4 Monte Carlo system of codes and added to the treatment planning system. The treatment planning system was then evaluated for its accuracy of calculations at low energies ...
Nitroaromatic radiosensitizers become metabolically bound preferentially to hypoxic cells and at least 10/sup 9/ adducts/cell can be tolerated as non-toxic. EMT-6 tumor cells have been incubated in hypoxia in the presence of /sup 3/H-Misonidazole and /sup 125/I-Azomycin Riboside for various times and the amount of /sup 3/H or /sup 125/I bound/cell was determined. Cells were stored as monolayers at 25"0C for up to 96 hr to accumulate radioactive decays and transferred at various times to 37"0C for colony-forming assays. No radiation inactivation was measured in cells which had incorporated at least 10/sup 6/ /sup 3/H or 10/sup 5/ /sup 125/I atoms. Previous studies had shown that -- 1% of MISO adducts to EMT-6 cells was associated with cellular DNA. These data indicate that the radiation-induced damage produced by these quantities of bound /sup 3/H or /sup 125/I causes little or not cell inactivation. The results of current studies to measure the ...
We irradiated proton beams on the ears of rabbits and the Harding-Passey mouse melanoma and observed their morphological change. We used 52 MeV proton beams from the INS-FM cyclotron. We adjusted the energy of the proton beams to be at the plateau part of the Bragg curve, at the half-way point of the Bragg peak, and at the Bragg peak. The amount of radiation was 5000rad in each case. The Harding-Passey mouse melanoma was transplanted into the subcutan of a three week old mouse. In this experiment, we used tumors, the diameter of which grew up to 1.5-2cm in 2-3 weeks after the transplantation. Using the jroscope, we observed both lightly and severely damaged cells. Using proton irradiation with the Bragg peak located at depth of 1mm in the rabbit's ears, we studied the change in the tissue. Irradiated epidermis fell off and was eroded because of radiation damage, but the rear surface of the rabbit's ears was only slightly ...
Background and purpose: A diagnosis of malignancy and its treatment is a very stressful time for patients and their families. This study was conducted to determine the impact of more intensive written information on patients' anxiety levels. The secondary aim was to determine the impact of this information on patients' satisfaction levels. Materials and methods: This prospective randomized trial consisted of patients with a pathological diagnosis of cancer having radical radiotherapy (RT). Patients were randomized to receive the more intensive information (including written information and a telephone call from the research nurse) or not to receive the more intensive information at the time of their initial consultation with the radiation oncologist. Study questionnaires measuring anxiety (STAI form) were completed prior to their first consultation (baseline) at the time of simulation (pre-RT) and at the completion of radiotherapy. A second questionnaire assessing ...
Purpose: To determine if involved field radiation (IF) is equivalent to standard whole bone radiation (SF) in local tumor control; to establish patterns of failure following treatment; and to determine response, event free (EFS) and overall survival rates from multi-disciplinary therapy in Ewing's Sarcoma (ES). Materials and Methods: Between 1983 and 1988, 184 children with ES were enrolled onto POG 8346. 178 (97%) met eligibility criteria; 6 had non-ES pathology. Induction treatment of Cyclophosphamide/Adriamycin (C/A) x 12 weeks was followed by local treatment either surgery or radiationtherapy (XRT) and C/A, Dactinomycin and Vincristine for 50 weeks. Resection was advised for patients with small primary tumors if accomplished without functional loss. 40 patients were randomized to receive SF, whole bone XRT to 39.6 Gy plus a 16.2 Gy boost (total 55.8 Gy) or IF to 55.8 Gy while ...
The side effects of cancer therapy on normal tissues limit the success of therapy. Generation of reactive oxygen species (ROS) has been implicated for numerous chemotherapeutic agents including doxorubicin...Full Text Available
BackgroundIt remains unclear if certain antiretroviral medications, particularly abacavir, compromise response to hepatitis C virus (HCV) therapy. Such data can inform...Full Text Available
A simple device is described which is used to determine treatment distance and beam direction in electron therapy employing one collimation. A technique for the production of irregular field templates and localization films is given.
ObjectivesTo investigate the effect of group cognitive behavioural therapy (CBT) for fatigue self-management, compared with groups receiving fatigue information alone, on fatigue...Full Text Available
BackgroundTo assess the relationship between improved regional and global myocardial function in patients with ischemic cardiomyopathy in response to β-blocker therapy or...Full Text Available
Current adherence assessments typically detect missed doses long after they occur. Real-time, wireless monitoring strategies for antiretroviral therapy may provide novel opportunities to proactively...Full Text Available
Epidermal growth factor receptor (EGFR) related therapies – mainly tyrosine kinase inhibitors (TKIs) such as erlotinib and gefitinib, but also monoclonal antibodies targeting EGFR, for example,...Full Text Available
BackgroundThe lack of adequate randomized clinical trials (RCT) has hindered identification of new therapies that are safe and effective for patients with primary focal segmental...Full Text Available
Photodynamic therapy (PDT) is an established endoscopic technique for ablating Barrett’s esophagus with high-grade dysplasia or early-stage intraepithelial neoplasia. The most common clinically...Full Text Available
The effect of Photofrin-based photodynamic therapy (PDT) and adjuvant treatment with serum vitamin D3-binding protein-derived macrophage-activating factor (DBPMAF) was examined using a mouse SCCVII...Full Text Available
BackgroundHerpes simplex virus (HSV) suppressive therapy reduces genital and plasma HIV-1 RNA over periods up to three months but the longer-term effect is unknown.Full Text Available
Somatic cell nuclear transfer or therapeutic cloning has provided great hope for stem cell-based therapies. However therapeutic cloning has been experiencing both ethical and technical difficulties....Full Text Available
ObjectiveTo evaluate the effect of different concomitant disease modifying antirheumatic drugs (DMARDs) on the persistence with antitumour necrosis factor (anti-TNF) therapies in...Full Text Available
Suppressed IL-12 production and maladaptive immune activation, both of which are ameliorated by successful highly active antiretroviral therapy (HAART), are thought to play important roles in the immunopathogenesis...Full Text Available
Purpose:The risks and benefits of continuing bisphosphonate therapy beyond 5 years in patients with primary osteoporosis have not been well established.Methods:We...Full Text Available
The heterogeneity of metastatic breast cancer mandates the need to select therapies taking into account tumor and patient characteristics. Chemotherapy is indicated in the palliative setting especially...Full Text Available
Multiple disease-specific systematic reviews on the effectiveness of physical therapy intervention for shoulder dysfunction have been inconclusive. To date, there have been two systematic reviews that...Full Text Available
IntroductionThe optimal dialysis dose for the treatment of acute kidney injury (AKI) is controversial. We sought to evaluate the relationship between renal replacement therapy (RRT)...Full Text Available
... and at that point she had already failed physical therapy, which someone else had prescribed, and so ... MRI, we may try a brief course of physical therapy to see if they feel better, but ...
Premature circuit clotting is a major problem in daily practice of continuous renal replacement therapy (CRRT), increasing blood loss, workload, and costs. Early clotting is related to bioincompatibility,...Full Text Available
This study was an evaluation of the performance of self-applied, blue light, light-emitting diode therapy in the treatment of mild-to-moderate inflammatory acne on the face, concerning: 1) time to improvement...Full Text Available
This joint statement was developed by the CMA and the Canadian Pharmaceutical Association, a national association of pharmacists, and includes the goal of drug therapy, strategies for collaboration...Full Text Available
BackgroundPostnatal glucocorticoid therapy in premature infants diminishes chronic lung disease, but it also increases the risk of hypertension in adulthood. Since glucocorticoid...Full Text Available
Adjuvant therapy aims to prevent outgrowth of residual disease but can induce serious side effects. Weighing conflicting treatment effects and communicating this information with patients is not elementary....Full Text Available
ObjectiveCOMBINE is the largest study of pharmacotherapy for alcoholism in the United States to date, designed to answer questions about the benefits of combining...Full Text Available
A numerical model was developed to simulate the combined effects of heat transfer, magnetite oxidation, and NO{sub x} formation in a grate-kiln furnace for taconite pellet induration. Heat transfer from the flame in the kiln was described by the net radiation method. The shrinking core model was used to account for magnetite oxidation on the grate. A novel approach to oxidation of tumbling pellets in a kiln was derived. The Zeldovich mechanism was used to predict thermal NO generation. Temperature fluctuations in the gas streams were estimated with a clipped Gaussian probability density function. The thermal energy balances and mass balances resulted in coupled systems of first-order differential equations, which were solved numerically. The model is capable of predicting NO production and magnetite oxidation in agreement with observation of plant performance. Although the design of the grate-kiln system is for efficient heat and mass transfer, ...
Spice extracts under the form of essential oils were tested for their efficiency to increase the relative radiosensitivity of Listeria monocytogenes and Escherichia coli O157H7 in culture media. The two pathogens were treated by gamma-irradiation alone or in combination with oregano essential oil to evaluate their mechanism of action. The membrane murein composition, and the intracellular and extracellular concentration of ATP was determined. The bacterial strains were treated with two irradiation doses: 1.2 kGy to induce cell damage and 3.5 kGy to cause cell death for L. monocytogenes. A dose of 0.4 kGy to induce cell damages, 1.1 kGy to obtain viable but nonculturable (VBNC) state and 1.3 kGy to obtain a lethal dose was also applied on E. coli O157H7. Oregano essential oil was used at 0.020% and 0.025% (w/v), which is the minimum inhibitory concentration (MIC) for L. monocytogenes. For E. coli O157H7, a concentration of 0.006% and 0.025% (w/v) which is the ...
An electron accelerator unit is described for electron beam therapy, comprising: a source of an electron beam; means for finally directing at least a portion of the beam to a therapy site, the directing means being mechanically independent of, and electrically isolated from, the source, and having a target area; and means for aligning the source with the directing means, the aligning means comprising means for projecting at least one beam of light from the source toward the target area.
An electron accelerator unit is described for electron beam therapy, comprising: a source of an electron beam; means for finally directing at least a portion of the beam to a therapy site, the directing means being mechanically independent of, and electrically isolated from, the source, and having a target area; and means for aligning the source with the directing means, the aligning means comprising means for projecting at least one beam of light from the source toward the target area.
The Monte Carlo transport codes LAHET and MCNP were used to calculate energy fluence spectra at three neutron therapy facilities. The results compare very favourably with measured data. Kerma spectra and the ratio of ICRU muscle tissue kerma to A-150 kerma, along the carbon to oxygen kerma ratio, were determined. Absorbed dose rate calculations are in reasonable agreement with measured values. Use of these codes to study modifications to existing therapy beams is briefly discussed. (author).
The anesthetic agents methohexital (Brevital), Innovar, and ketamine (Ketaject) were examined for their effect on seizure duration following electroconvulsive stimulation in a rat model of electroconvulsive therapy (ECT). Compared to unanesthetized control animals, methohexital anesthesia shortened seizure duration by 42%, ketamine anesthesia tended to increase seizure duration, and Innovar anesthesia had no effect on duration of seizures. PMID:7349626
The Argonne Boundary Layer Experiments (ABLE) facility, located in south central Kansas, east of Wichita, is devoted primarily to investigations of and within the planetary boundary layer (PBL), including the dynamics of the mixed layer during both day and night; effects of varying land use and land form; the interactive role of precipitation, runoff, and soil moisture; storm development; and energy budgets on scales of 10 to 100 km. Located entirely within the Walnut River watershed, ABLE provides intense measurements within the northeast quadrant (Fig. 1) of the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) of the Atmospheric Radiation Measurement (ARM) Program (Stokes and Schwarz, 1994). By combining the continuous measurements of ABLE with ancillary continuous measurements of, for example, the ARM and the Global Energy Water cycle Experiment (GEWEX) (Kinster and Shukla, 1990) programs, ABLE provides a ...
General estimates and references are made in connection with the role of technological physics in obtaining materials with specific features. The first part of the paper presents the modification of weak wood essences as well as technological processes at bench-scale and semi industrial scale of wood-plastic composites, under various irradiation conditions. Two technological installations for the fabrication of wood-plastic composites on both scales with technical and practical specifications of their performances are presented. Experimental data for different wood-plastic composite systems using some local wood essences in combination with several polymer and copolymer systems are given. Impregnation and polymerization levels are mentioned for every specific system. The radiation dose rate and integrated dose are given for every experimental polymerization system. The features of the wood-plastic composites are compared with the initial wood ...
Non-destructive methods of diagnosis for detecting cable degradation by aging are being studied recently for improvement of electric wires and cables. This study examines degradation behaviors of cable sheath and insulation by combined accelerated aging tests applying thermal and radiation stresses simultaneously using a typical low voltage cable. According to experiments, elongation of cross-linked polyethylene insulation deteriorated at a faster rate than PVC sheath did under low doses below 50 Gy/h. Therefore, measurements using a time domain dielectric spectrometer (TDS) were carried out for the purpose of developing a method of degradation diagnosis of insulation. It was found that values of tan#delta# measured at very low frequencies below 0.1 Hz increase in pace with degradation of insulation reflecting the level of degradation more effectively than those measured at frequencies around the commercial frequency. In order to consider ...
This work estimates the power requirements for using photochemical processes driven by space nuclear power to counteract the Earth's ozone layer depletion. The total quantity of ozone (O_3) in the Earth's atmosphere is estimated to be about 4.7 x 10"3"7 molecules. The ozone production and destruction rates in the stratosphere are both on the order of 4.9 x 10"3"1 molecules/s, differing by a small fraction so that the net depletion rate is about 0.16 to 0.26% per year. The delivered optical power requirement for offsetting this depletion is estimated to be on the order of 3 GW. If the power were produced by satellite reactors at 800 km altitude (orbit decay time #approx# 300 years), some means of efficient power beaming would be needed to deliver the power to stratospheric levels (10--50 km). Ultraviolet radiation at 140--150 nm could have higher absorption rates in O_2 (leading to production of atomic oxygen, which can combine with O_2 to form ...
We review results from general relativistic axisymmetric magnetohydrodynamic simulations of accretion in Sgr A*. We use general relativistic radiative transfer methods and to produce a broad band (from millimeter to gamma-rays) spectrum. Using a ray tracing scheme we also model images of Sgr A* and compare the size of image to the VLBI observations at 230 GHz. We perform a parameter survey and study radiative properties of the flow models for various black hole spins, ion to electron temperature ratios, and inclinations. We scale our models to reconstruct the flux and the spectral slope around 230 GHz. The combination of Monte Carlo spectral energy distribution calculations and 230 GHz image modeling constrains the parameter space of the numerical models. Our models suggest rather high black hole spin ($a_*\\approx 0.9$), electron temperatures close to the ion temperature ($T_i/T_e \\sim 3$) and high inclination angles ($i ...
We investigate some aspects of the radiation damage mechanisms in biomolecules, focusing on the modelling of resonant fragmentation caused by the attachment of low-energy electrons (LEEs) initially ejected by biological tissues when exposed to ionizing radiation. Scattering equations are formulated within a symmetry-adapted, single-center expansion of both continuum and bound electrons, and the interaction forces are obtained from a combination of ab initio calculations and a nonempirical model of exchange and correlation effects developed in our group. We present total elastic scattering cross-sections and resonance features obtained for the equilibrium geometries of glycine, alanine, proline and valine. Our results at those geometries of the target molecules are briefly shown to qualitatively explain some of the fragmentation patterns obtained in experiments. We further carry out a one-dimensional (1D) modeling for the ...
The project is described, the motivation for the research and the microclimate is defined in relation to both building physics research and applications. Air temperatur, air humidity, solar radiation and air velocity are briefly considered, whilst driving rain and long-wave radiation are described in more detail. Convective heat transfer and surface coefficients are discussed, although they are not microclimatic factors, merely resulting from combinations of such factors. They are included as they are important in relation to transfer of heat and moisture at the surface of the building envelope. Driving rain measurement is the main area of interest, including development of measurement equipment. Long-wave irradiation is measured and compared with empirical formulae from the literature. Window convection heat transfer is another main area of interest. Nocturnal convective heat transfer from a double pane glazing is studied ...
Classification and ranking of the solid solution on their reaction to the irradiation is suggested on the basis of binary system structure controlled by mixing enthalpy sign, melting temperatures relation of components and solidus curves slope. Several combinations of these characteristics permit to pick out three groups of substitutional elements capable of forming the vacancy-solute atom complexes either low-mobile or fast-mobile ones as compared to monovacancies migration. The radiation hardening (and embrittlement) of binary alloys should be intensified respectively either due to heterogeneous point defect clusters nucleation on solute traps or due to solute atom clusters/ precipitate formation. A local cohesion decrease may also occur especially if low-melting elements (characterized by low surface energy) are segregating on internal sinks or grain boundaries. The predicted specifics of different alloy group under irradiation and during ...
A combination of measuring instruments, consisting of a Beta-Sedimeter and a radionuclide X-ray fluorescence instrument, is described. With the Beta-Sedimeter the C-14-radiation is measured. Through direct irradiation with photons of a Pu238-source in an ancillary irradiation chamber and energy dispersing measurement of the K- and L-radiation resp. of the excited heavy metals with the aid of a Si(Li)-semiconductor detector and a 4-channel analyzer the heavy metal concentrations of the heavy metals Zn, Cr, Ni and Pb are determined. For the determination of cadmium the indirect excitation with Am-241 and Dy-targets is described. The system produces records and operates fully automatically in a step-by-step mode with a testing cycle of 45 minutes. In connection with the process monitoring of the wastewater from a zinc plating plant during a period of 8 months the concentration of the solid material and of the metals Cr and Zn, ...
This research focuses on the development and application of high order statistical analyses applied to measurements performed with subcritical fissile systems driven by an introduced neutron source. The signatures presented are derived from counting statistics of the introduced source and radiation detectors that observe the response of the fissile system. It is demonstrated that successively higher order counting statistics possess progressively higher sensitivity to reactivity. Consequently, these signatures are more sensitive to changes in the composition, fissile mass, and configuration of the fissile assembly. Furthermore, it is shown that these techniques are capable of distinguishing the response of the fissile system to the introduced source from its response to any internal or inherent sources. This ability combined with the enhanced sensitivity of higher order signatures indicates that these techniques will be of significant utility ...
The US Department of Energy (DOE) sponsors an extensive research program to improve the methods, dosimeters, and instruments available to DOE facilities for measuring neutron dose and assessing its effects on the work force. The Total Dose Meter was recently developed for measuring in real time the adsorbed dose of mixed neutron and gamma radiation and for calculating the dose equivalent. The Field Neutron Spectrometer was developed to provide a portable instrument for determining neutron spectra in the workplace for flux-to-dose equivalent conversion and quality factor calculation. The Combination Thermoluminescence/Track Etch Dosimeter (TLD/TED) was developed to extend the effective neutron energy range of the conventional TLDs to improve detection of fast-energy neutrons. An Optically Stimulated Luminescence Dosimeter is presently being developed for application to gamma, neutron, and beta radiation. An Effective Dose ...
We describe a panoramic stigmatic spectrograph comprising a grazing-incidence toroidal mirror and a large-aperture free-standing transmission diffraction grating (5000 lines mm-1 ). Two spectrograph versions were constructed, with grazing angles of 7.6 and 40 and the short-wavelength spectral limits near 4 and 1.5 nm. The spectrograph aberrations were studied by numerical ray tracing. The spectrograph was used to record line and quasi-continuous spectra (1.5 - 30 nm) of multiply charged ions in a plasma generated by the second-harmonic pulses of an yttrium aluminate laser (Q = 0.15 J, ? = 5 ns, ? = 0.54 ?m, repetition rate = 0.5 Hz). In combination with a laser-produced plasma radiation source, the arrangement was used to characterise soft x-ray optical components and to generate collimated beams of polarised radiation in the 14 - 20 nm range. (laser applications and other topics in quantum electronics)
Purpose/Objective: With the advent of computed tomography and magnetic resonance imaging, the three dimensional representation of the patient anatomy has become an invaluable resource for better diagnosis and delineation of the target volume and sensitive structures in radiationtherapy. Although the therapeutic linear accelerator industry has made available highly sophisticated equipment, the aggressiveness in dose prescription and delivery has to be complimented by accurate dose computation methods. We have adopted a convolution/superposition algorithm for the calculation of absolute dose that fully accounts for the external shape and internal structure of the patient for photon treatment radiotherapy. In this paper, we will discuss the principles of the convolution algorithm and we will show how the computed dose compares to clinically relevant treatment techniques. Materials and Methods: A computer controlled data acquisition system and a ...
With the advent of intensity-modulated radiationtherapy (IMRT), the inclusion of heterogeneity corrections is further complicated by the conformal delivery of many small beams forming steep dose gradients. Radiation treatment planning has evolved to take into account even small changes in tissue density so that the dose to tumor can be further optimized. However, different treatment planning systems incorporate different heterogeneity correction algorithms, and it is unclear whether any of these algorithms are superior to others in terms of accurately predicting delivered radiation doses relative to measurement in a clinical setting. The purpose of this study was to determine the accuracy of heterogeneity dose calculations from two widely used IMRT treatment planning systems (Pinnacle and Corvus) against measurement. These two systems handle heterogeneity dose corrections by means of a collapsed-cone ...
In this paper we present status and developments of the Duke storage ring facility. The Duke storage ring facility provides the unique combination of phase-locked light sources ranging from high power OK-4 XUV FEL to quasimonochromatic {gamma}-ray beam and IR/X-ray spontaneous radiation. The XUV OK-4 FEL, which is collaborative project with BlNP, Novosibirsk, is in operation since November, 1996. The OK-4 UV FEL is also used for production of nearly monochromatic {gamma}-ray s with tunable energy. We present the results of UV lasing with the OK4 FEL and selected results of its applications. We will discuss our future plans for extension of this source and status of the construction of dedicated used facility adjacent to the FEL building. (author)
On the 15th of June 2006 the PAMELA experiment, mounted on the Resurs DK1 satellite, was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. PAMELA is a satellite-borne apparatus designed to study charged particles in the cosmic radiation, to investigate the nature of dark matter, measuring the cosmic-ray antiproton and positron spectra over the largest energy range ever achieved, and to search for antinuclei with unprecedented sensitivity. The apparatus comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail catcher scintillator and a neutron detector. The combination of these devices allows charged particle identification over a wide energy range.
The two most important issues in designing future gravitational wave interferometric detectors are, in our opinion, thermal and optical noise. In this paper we discuss some approaches for reducing these noises. About thermal noise we show a possible cryogenic solution. About optical noise (namely, the combined effect of shot noise and radiation pressure noise) we show that it is possible to apply a recently proposed reduction strategy based on a 'quantum feedback' (Courty et al 2003 Phys. Rev. Lett. 90 083601; Courty et al 2003 Preprint gr-qc/0301068) to a full Fabry-Perot cavity. This can be seen as a further step towards the practical realization of a detector which is able to evade the standard quantum limit.
This study presents results from Monte Carlo radiation transport calculations aimed at characterizing a novel methodology being developed to detect partial defects in Pressurized Water Reactor (PWR) spent fuel assemblies (SFAs). The methodology uses a combination of measured neutron and gamma fields inside a spent fuel assembly in an in-situ condition where no movement of the fuel assembly is required. Previous studies performed on single isolated assemblies resulted in a unique base signature that would change when some of the fuel in the assembly is replaced with dummy fuel. These studies indicate that this signature is still valid in the in-situ condition enhancing the prospect of building a practical tool, Partial Defect Detector (PDET), which can be used in the field for partial defect detection.
The present article will review recent advances in focused ion beam (FIB) technology. With increasing demands for scale of integration, microfabrication technology is becoming more important and various new microfabrication tools and processing techniques are desired. FIB is one of the promising tools for future microfabrication technology. This provides maskless patterning capability, which is of importance for process simplification, nanofabrication and in the development of in situ vacuum processing. In situ vacuum processing systems are being developed by combining FIB and a molecular beam epitaxy system. Radiation damage may limit applications of FIB. However, it was demonstrated that low energy FIB (<1 keV) with very high brightness was reached and promising results for low damage processing have been obtained. (orig.).
Electron beam (EB) processing involves using electrons to initiate polymerization or cross-linking reactions in suitable substrates, thereby enhancing specific physical and chemical properties. A relatively new use of EB processing is now emerging: the production of fibre-reinforced composites. EB curing at ambient temperature has the potential to reduce the residual stresses in an advanced composite, a result of expansion during thermal curing, and to significantly increase the overall cure speed and process throughput. Wood fibres are used as a filler material for various thermoplastics such as polypropylene. EB treatment, combined with selected EB-curable coupling agents, significantly increases the adhesion between the wood fibres and the thermoplastic polymer, resulting in improved material properties. Work to develop both products and processes for the EB curing of fibre-reinforced composites is currently underway at AECL Research. This paper briefly updates ...
This Final Report documents the research accomplishments achieved in the first phase of operations of a new Advanced Photon Source beam line (7-ID MHATT-CAT) dedicated to real-time x-ray studies. The period covered by this report covers the establishment of a world-class facility for time-dependent x-ray studies of materials. During this period many new and innovative research programs were initiated at Sector 7 with support of this grant, most notably using a combination of ultrafast lasers and pulsed synchrotron radiation. This work initiated a new frontier of materials research: namely, the study of the dynamics of materials under extreme conditions of high intensity impulsive laser irradiation.
The aim of the present investigation was to study the effect of weather and available protection on the behaviour of outdoor-wintered beef cattle (Bos taurus). A herd of 78-85 cattle head was studied during four winter months in the Southwest of Sweden. Protection was offered by coniferous forest situated on and around the 12ha pasture, which we divided into protection categories. During 240h we observed 10 cows and 10 heifers as focal animals (each 3h/month) during day time and adjusted observation times to the altitude of the sun. Close to the animals and at an unprotected spot of the pasture we measured temperature, wind speed and solar radiation and combined these variables to a single measure called Wind Chill Temperature (WCT). During observations the animals were in the forest in 12...
The objective of this work was to combine asymmetric somatic hybridization (donor-recipient fusion or gamma fusion) to microprotoplast-mediated chromosome transfer, as a tool to be used for chromosome mapping in Citrus. Swinglea glutinosa micro protoplasts were irradiated either with 50, 70, 100 or 200 gamma rays and fused to cv. Ruby Red grapefruit or Murcott tangor protoplasts. Cell colonies were successfully formed and AFLP analyses confirmed presence of S. glutinosa in both 'Murcott' tangor and 'Ruby Red' grapefruit genomes. (author)
Since the advent of the first free electron laser (FEL) in 1976 up to now, a series of principles, configurations and operation modes of these FELs have been devised and partially implemented. The principles refer to transverse FEL, longitudinal FEL, combined FEL, and transverse optical klystron FEL. Configurations may be standard or many-stage and the undulators may be magnetostatic, electrostatic or electromagnetic. The operation regimes may be low-gain Compton type, high-gain Compton type, Raman type, with and without space charge. The operation modes may be the amplification of an external coherent EM radiation, a self-amplified spontaneous emission (SASE), or an oscillator. The paper presents in detail these concepts and the limit between classical approach and the quantum approach of FEL. (Author).
Isotropic Compton profiles of TaC and TaN have been measured for the first time, at an intermediate resolution, using 662 keV #gamma#-radiation. Energy bands, density of states and Fermi surface topology of TaC and TaN have been computed using linear combination of atomic orbitals with density functional theory and full potential linearised augmented plane wave method. Both band structure calculations predict the metallic character of TaC and TaN. The electron momentum densities calculated using various approaches of density functional theory are compared with the present measurements. On the basis of Mulliken's population, it is also seen that TaC has more covalent bonding than TaN. The optical properties computed using full potential linearised augmented plane wave method are explained in terms of intraband transitions.
With the combination of source ventilation and ceiling cooling for air-conditioning of working and recreation rooms, a ventilation system is available which fulfills the highest demands regarding thermal comfort. In order to utilize the advantages of this ventilation system with regard to air quality and thermal comfort to an optimum, the influence of the radiation exchange between cooling ceiling and walls on the flow in the room is investigated experimentally. Energy transfer from the walls to the cooled ceiling may result in an insufficient temperature of the walls compared to ambient air and in an upward flow on the wall surfaces (downward flow of) driven by gravity, which influences the flow pattern in the case of source ventilation. (orig.)
X-ray diffraction offers a unique combination of advantages for kinetic study which include the non-destructive nature of the measurement, the use of bulk crystals, and the convenience of the experimental arrangements. These attributes and the availability of position-sensitive detectors and high-flux synchrotron radiation sources make this technique most useful for in situ, dynamical investigations. When using diffraction techniques to determine a diffusion coefficient, the principle of analysis entails a scattering theory and a kinetic model. The former allows the kinetic parameter(s) to be extracted from measured intensity, while the latter relates the kinetic parameter(s) to the diffusion coefficient(s). Three examples are demonstrated: (1) Palladium Silicide (Pd{sub 2}Si) Layer Growth on Silicon, (2) Decomposition of an Ni-12.5at%Si Superalloy, and (3) Short-range Ordering in Cu-Au Solid Solutions.
The Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, developed an alignment strategy to specify elemental depth profiling in vertical sidewall layers on structured wafers. For this purpose, PTB's irradiation chamber for 200?mm and 300?mm silicon wafers was used to combine total-reflection X-ray fluorescence (TXRF) and grazing incidence XRF (GIXRF) techniques by employing monochromatized undulator radiation of the BESSY II electron storage ring. 3-D test structures were fabricated to develop an optimal alignment strategy allowing for depth profiling in such nanolayers. The test structures consisted of silicon bars with widths/spacings either in the ?m or in the nm range. In order to be able to differentiate the sidewalls more easily from the remainder of ...
There are several methods of generating OH free radicals from ozone and/or hydrogen peroxide and ultraviolet light. They all have in common that the OH free radicals originate in one single source only whereas in the combination of ozone with ionizing radiation two simultaneous working sources for the OH free radicals exist. The resulting higher OH free radical concentration makes this process especially apt for the remediation of low level contaminated groundwater as for example trichloroethylene (TCE) contamination in the sub-ppm range. A cost comparison between O_3/UV and O_3/electron beam for remediation of a groundwater contaminated with 100 ppb TCE indicated that for a throughput of about 5 million gallons/day the O_3/electron beam process is more cost-effective. (authors).
Two neutron emesis experiments were conducted at the Armed Forces Radiobiology Research Institute (AFRRI). In both experiments (described as Phase I and Phase II) the radiation dose required to cause emesis in 50% of subjects (ED50) was determined for both neutron reactor and gamma reactor source radiation. Emesis onset, offset and duration times post-exposure are reported. Neutrons were maximized from the reactor by passing the beam through a 15.25 cm (6 in.) thick lead wall to filter out gamma photons. Gamma rays were maximized by thermalizing neutrons in 30.5 cm (12 in.) of water, then absorbing the thermal neutrons in a gadolinium-cadmium shield. In Phase I, 28 dogs were exposed to radiation: 12 were exposed to gamma photons at the rate of 0.69 Gy/min and 16 were exposed to neutrons at 1.2 Gy/min. In Phase II, 58 dogs in 3 groups were exposed to radiation: 19 were exposed in the gamma group at 0.75 ...
Large-scale field tracer experiments have been conducted on Ulchin, Wolsung and Daeduk sites for the purpose of validating FADAS and of analyzing the environmental characteristics around the nuclear sites. The most influential factor in atmospheric dispersion is the meteorological condition. During the experiment, meteorological data were measured on the release point and the selected positions among sampling points. Once radioactive materials are released to the atmosphere, members of public may be exposed through the environmental media such as air, soil and foods. Therefore, to protect the public, adequate countermeasures should be taken at due time for those exposure pathways. both processes, of justification and optimization are applied to a countermeasure simultaneously for decision-making. The work scope of Biological research for the radiation protection had contained the search of biological microanalytic methods for assessing the health effect by ...
The development of a flat response small size, real time neutron dosimeter and ratemeter for the energy range of about 1 eV to 14 MeV is presented. This dosimeter is adequate for measuring neutron dose equivalents of 3 mRem up to 100 Rem and dose rates of 300 mRem/h to 50 Rem/h or more. The dosimeter consists of four Si surface barrier detectors. _1_0B radiators are placed in front of three of the detectors and a polyethylene radiator is placed in front of the fourth one. The _1_0B pellets are used for dose equivalent measurements in the energy range 1 eV to proportional1 MeV. The polyethylene radiator, made in two parts having thicknesses of 10 and 100 mg/cm_2 in an area ratio of 8 to 1, flattens the response to +-40% in the energy range 1-14 MeV. The signal-to-background ratio for different Si surface barrier detectors and for _1_0B polyethylene radiators was investigated. This dosimeter can give a ...
AbstractBackground: So far, infliximab (IFX) therapy for the treatment of Crohn's disease (CD) has generally been guided by clinical symptoms. Data on treatment response as ascertained by endoscopy in IFX therapy are scarce. The aims of this study were to measure the endoscopic response rate during IFX induction and maintenance therapy in luminal CD, and also evaluate the role of endoscopy in monitoring IFX therapy. Methods: Data obtained from 71 patients with active luminal CD and treated with IFX were analyzed retrospectively. The endoscopy findings were scored according to mucosal activity as: 0 (remission), 1-2 (mild), 3-4 (moderate), and 5-6 (severe). A positive endoscopic response was determined by a decrease in score of at least two points and mucosal healing was assigned a score of...
The performance of four different organic coating systems applied to carbon and weathering steel coupons has been assessed in this investigation. applied on the surface of carbon steel and weathering steel coupons. The coupons have been evaluated using five different tests, three field tests and two accelerated tests. The field tests were carried out at three atmospheric stations, located at COSIPA in Cubatao-SP, at Alto da Serra in Cubatao-SP and at Paula Souza in Sao Paulo city. The accelerated tests consisted of (a) exposure to alternate cycles of ultraviolet radiation/condensation combined with salt spray cycles (UVCON combined with Salt Spray) and of (b) exposure to alternate cycles of ultraviolet radiation/condensation combined with the Prohesion test. The performance of the coatings was assessed by visual observation and photographs, using a method based on ASTM D-610, ASTM ...
Full text: Radiotherapy treatment planning (RTP) relies heavily on medical imaging. Until recently, the most important planning tool was the treatment simulator. The kilovoltage radiographic capabilities in a treatment simulator enabled the boundaries of treatment fields to be visualized with respect to bony anatomic landmarks. Perhaps the most important advance in treatment planning in recent years is the ability to visualize the passage of the beams with respect to a more accurate geometrical representation of the tumor and other soft tissue structures. This 'virtual simulation' uses a computer-based representation of a patient to determine the extent of the disease and the location of radiation sensitive normal tissue. Computer tomographic (CT) imaging produces a high-resolution three-dimensional representation of anatomy that can be correlated with other image sets such as magnetic resonance images (MRI) of function. Positron emission tomographic (PET) imaging ...
Purpose: Patients with ataxia-telangiectasia (A-T) show greatly increased radiation sensitivity and cancer predisposition. Family studies imply that the otherwise clinically silent heterozygotes of this autosomal recessive disease run a 3.5 to 3.8 higher risk of developing cancer. In vitro studies suggest moderately increased cellular radiation sensitivity of A-T carriers. They may also show elevated clinical radiosensitivity. We retrospectively examined patients who presented with severe adverse reactions during or after standard radiation treatment for mutations in the gene responsible for A-T, ATM, considering a potential means of future identification of radiosensitive individuals prospectively to adjust dosage schedules. Material and Methods: We selected 20 cancer patients (breast, 11; rectum, 2; ENT, 2; bladder, 1; prostate, 1; anus, 1; astrocytoma, 1; Hodgkins lymphoma, 1) with Grade 3 to 4 (RTOG) acute and/or late ...
Naturally occurring radionuclides are present in most material. The most common naturally occurring radionuclides in material are those of the uranium and thorium series and potassium-40. This material is commonly referred to as Naturally Occurring Radioactive Material (NORM). In some material the levels of naturally occurring radionuclides are significantly higher, to the extent that regulatory control may be required for radiation protection purposes. Regulation of NORM presents a range of new challenges for both regulators and operators. Unlike more traditional industries dealing with radionuclides, NORM industries have generally not had any radiological oversight and, for example, are not equipped for radiological monitoring. Some consumer goods containing NORM, which have not traditionally been considered as a radiological problem (such as some fertilizers), may require regulation and this may have social and economic consequences. The transport and disposal ...
The Plasma and Ion Source Technology Group at the Lawrence Berkeley National Laboratory have been developing rf-driven ion sources for the last two decades. These sources are being used to generate both positive and negative ion beams. Some of these sources are operating in particle accelerators such as the Spallation Neutron Source (SNS) at Oak Ridge, while others are being employed in various industrial ion beam systems. There are four areas where the rf-driven ion sources are commonly used in industry. (1) In semiconductor manufacturing, rf-driven sources have found important applications in plasma etching, ion beam implantation, and ion beam lithography. (2) In material analysis and surface modification, miniature rf-ion sources can be found in focused ion beam systems. They can provide ion beams of essentially any element in the Periodic Table. The newly developed combined rf ion-electron beam unit improves greatly the performance of the secondary ion mass ...
Feline heartworm disease is a very different clinical entity from canine heartworm disease. In cats, the arrival and death of immature heartworms in the pulmonary arteries can cause coughing and dyspnea as early as 3 months postinfection. Adult heartworms suppress the function of pulmonary intravascular macrophages and thus reduce clinical disease in chronic feline heartworm infection. Approximately 80% of asymptomatic cats self-cure. Median survival time for symptomatic cats is 1.5 years, or 4 years if only cats living beyond the day of presentation are considered. Aberrant worm migration is more frequent than it is in dogs, and sudden death can occur with no prior clinical signs. The bacterial endosymbiont Wolbachia likely contributes to the inflammatory pathology of heartworm disease, but its role is not yet fully clear. Unfortunately, the diagnosis, treatment, and management of feline heartworm disease are far from simple. Antemortem diagnosis is hampered by low worm burdens, the ...
To determine the effectiveness and patency of percutaneous intervention in insufficient native arteriovenous hemodialysis fistulae (AVFs). Between March 1997 and September 2001, 67 cases of insufficient native AVFs resulted from central vein lesion, PTA was performed in 48 cases, and thrombolytic therapy with or without PTA in 11. In eight of the cases, in which central vein stenosis had led to the insufficency, percutaneous transluminal angioplasty (PTA) was performed, and in three of the eight, a stent was inserted. Angiography findings and complications, as well as success and patency rates in the non-thrombosis and thrombosis group, were evaluated; the central vein lesion group was analysed separately. Among 84 lesions observed at angiography, three were 54 cases of stenosis, 17 of occlusion, and 13 of combined thrombosis. The lesions were located in a proximal vein (n=51), distal vein (n=14), artery (n=6), and at the site of anastomosis ...
The NCRP Wound Model, which describes the retention of selected radionuclides at the site of a contaminated wound and their uptake into the transfer compartment, has been combined with the ICRP element-specific systemic models for those radionuclides to derive dose coefficients for intakes via contaminated wounds. These coefficients can be used to generate derived regulatory guidance (i.e., the activity in a wound that would result in an effective dose of 20 or 50 mSv, or in some cases, a organ-equivalent dose of 500 mSv) and clinical decision guidance (i.e., activity levels that would indicate the need for consideration of medical intervention to remove activity from the wound site, administration of decorporation therapy or both). Data are provided for 38 radionuclides commonly encountered in various activities such as nuclear weapons, fuel fabrication or recycling, waste disposal, medicine, research, and nuclear power. These include 3H, 14C, ...
In order to achieve micro-wound, intelligence and high efficiency for fracture setting, intelligent setting system for fracture is proposed in accordance with biomechanics and fracture therapy theory. In the comprehensive medical system based on C-shape-arm X-machine, image processing and analysis is the core, programmable logical controller and stepping motor are important driving parts controlling mechanical parts. Six degree of freedom dynamics sensor ensures to control accurately force and moment. On the foundation of analyzing X-ray image peculiarities, method of processing and analysis is put forward, combining time domain with frequency domain. After mining domain knowledge in depth, setting actions is quantized into three non-continuous steps and is parameterized into two angles and one distance aiming at femoral-neck fracture. Objective features are extracted by virtue of three power polymerization curved surface fitting. Master-slave ...
Purpose: Extrahepatic cholangiocarcinoma is a rare malignancy. Despite radical resection, survival remains poor, with high rates of local and distant failure. To clarify the role of radiotherapy with chemotherapy, we performed a retrospective analysis of resected patients who had undergone chemoradiotherapy. Methods and Materials: A total of 45 patients (13 with proximal and 32 with distal disease) underwent resection plus radiotherapy (median dose, 50.4 Gy). All but 1 patient received concurrent fluoropyrimidine-based chemotherapy. The median follow-up was 30 months for all patients and 40 months for survivors. Results: Of the 45 patients, 33 underwent adjuvant radiotherapy, and 12 were treated neoadjuvantly. The 5-year actuarial overall survival, disease-free survival, metastasis-free survival, and locoregional control rates were 33%, 37%, 42%, and 78%, respectively. The median survival was 34 months. No patient died perioperatively. Patient age #<=#60 years and perineural ...
Thirty-nine previously untreated patients with squamous cell carcinoma of the tongue were treated by irradiation or a combination of irradiation and surgery, with or without chemotherapy, between January 1971 and December 1980. All of the patients had a follow-up period of at least nine years. Twenty-two patients were men and 17 were women. The average age was 50.1 years, with a range of 30 to 74 years. The absolute five-year survival rate was 82.1% and the cumulative ten-year survival rate 76.9% for these 39 patients. Cervical node metastases were clinically found on admission in 14 patients whose five-year survival rate was 64.3%, whereas it was 92.0% for 25 patients without metastasis. The absolute five-year survival rate decreased from 92.3% for patients with stage I lesions to 90.9%, 87.5% and 42.9% for those with stage II, stage III and stage IV lesions, respectively. Most of the patients received external irradiation and intraoral electron beam ...
To date, no single passive detector has been found that measures dose equivalent from ionizing radiation exposure in low-Earth orbit. We have developed the I.S.S. Passive Dosimetry System (P.D.S.), utilizing a combination of TLD in the form of the self-contained Pille TLD system and stacks of CR-39 plastic nuclear track detector (P.N.T.D.) oriented in three mutually orthogonal directions, to measure total dose and dose equivalent aboard the International Space Station (I.S.S.). The Pille TLD system, consisting on an on board reader and a large number of Ca{sub 2}SO{sub 4}:Dy TLD cells, is used to measure absorbed dose. The Pille TLD cells are read out and annealed by the I.S.S. crew on orbit, such that dose information for any time period or condition, e.g. for E.V.A. or following a solar particle event, is immediately available. Near-tissue equivalent CR-39 P.N.T.D. provides Let spectrum, dose, and dose equivalent from charged particles of ...
The case of spontaneous radiation of channeled ultrarelativistic particles is considered when the dipolarity condition is not satisfied. The change of the particle longitudinal velocity affecting the maximum radiation frequency is included. The angular and frequency characteristics of the radiation for superhigh energies are studied for the first time. It is shown that there is an optimum energy at which the radiation density is maximum. The influence of the angle at which electrons enter a crystal and of the beam divergence on the radiation is investigated. The problem of quasichanneled particle radiation and also the radiation in axis-plane transitions are considered. (author).
Purpose: Previous data suggest that the PKC? catalytic V5 (PKC?-V5) heptapeptide (HEPT) (FEQFLDI) binds HSP27 and blocks HSP27-mediated radio- or chemoresistance. Here we investigated further the in vivo function of the PKC?-V5 HEPT. Methods and Materials: Labeling of HEPT with Cy5.5 or fluorescein isothiocyanate was performed to evaluate in vitro or in vivo distribution of HEPT. A clonogenic survival assay, flow cytometry, and Western blotting of cleaved caspase-3 were performed to determine in vitro sensitization effects of HEPT plus ionizing radiation (IR) versus IR alone or those of HEPT plus cisplatin(Cis) versus Cis alone. A nude mouse xenografting system was also applied to detect in vivo sensitizing effects of HEPT. Results: HEPT efficiently bound to HSP27 and showed sensitization after combined treatment with IR versus treatment with Cis alone in NCI-H1299 lung carcinoma cells, with higher HSP27 expression, which was similar to that of ...
Background: Some former retrospective studies have suggested that patients with Ewing's sarcoma might have a very high risk for developing secondary sarcomas if treated with radiotherapy. We have evaluated the risk of second malignancies (SM) in patients treated in the German Cooperative Ewing's Sarcoma Studies CESS 81 and CESS 86. Materials and methods: From January 1981 through June 1991, a total number of 674 patients was registered in the two multicentric Ewing's sarcoma trials CESS 81 (1981 through 1985) and CESS 86 (1986 through June 1991). The systemic treatment consisted in both studies of a four-drug-chemotherapy (VACA= vincristine, actinomycin D, cyclophosphamide and adriamycin; or VAIA= vincristine, actinomycin D, ifosfamide and adriamycin) and a total number of four courses, each lasting nine weeks, was recommended by the protocol. Local therapy was either complete surgery or surgery plus postoperative radiotherapy with 36-46Gy or definitive ...
An add-on multileaf collimator for electrons (eMLC) has been developed that provides computer-controlled beam collimation and isocentric dose delivery. The design parameters result from the design study by Gauer et al (2006 Phys. Med. Biol. 51 5987-6003) and were configured such that a compact and light-weight eMLC with motorized leaves can be industrially manufactured and stably mounted on a conventional linear accelerator. In the present study, the efficiency of an initial computer-controlled prototype was examined according to the design goals and the performance of energy- and intensity-modulated treatment techniques. This study concentrates on the attachment and gantry stability as well as the dosimetric characteristics of central-axis and off-axis dose, field size dependence, collimator scatter, field abutment, radiation leakage and the setting of the accelerator jaws. To provide isocentric irradiation, the eMLC can be placed either 16 or 28 cm above the ...
Systematics of neutron capture radiative width were studied in the target element range from Th to Cm. Reduced radiative widths were analyzed with a simple radiative width formula based on E1 transition. Average radiative width is presented with the standard deviation of 15%. (author)
For a given linac design, the dosimetric characteristics of a photon beam are determined uniquely by the energy and radial distributions of the electron beam striking the x-ray target. However, in the usual commissioning of a beam from measured data, a large number of variables can be independently tuned, making it difficult to derive a unique and self-consistent beam model. For example, the measured dosimetric penumbra in water may be attributed in various proportions to the lateral secondary electron range, the focal spot size and the transmission through the tips of a non-divergent collimator; the head-scatter component in the tails of the transverse profiles may not be easy to resolve from phantom scatter and head leakage; and the head-scatter tails corresponding to a certain extra-focal source model may not agree self-consistently with in-air output factors measured on the central axis. To reduce the number of adjustable variables in beam modelling, we replace the focal and ...
The aim of this study was to evaluate the results of postoperative radiotherapy in a case of perihilar cholagiocarcinoma by analyzing overall survival rate, patterns of failure, prognostic factors for overall survival, and toxicity. Between January 1998 and March 2008, 38 patients with perihilar cholangiocarcinoma underwent a surgical resection and adjuvant radiotherapy. The median patient age was 59 years (range, 28 to 72 years), which included 23 men and 15 women. The extent of surgery was complete resection in 9 patients, microscopically positive margins in 25 patients, and a subtotal resection in 4 patients. The tumor bed and regional lymphatics initially received 45 Gy or 50 Gy, but was subsequently boosted to a total dose of 59.4 Gy or 60 Gy in incompletely resected patients. The median radiotherapy dose was 59.4 Gy. Concurrent chemotherapy was administered in 30 patients. The median follow-up period was 14 months (range, 6 to 45 months). The 3-year overall survival and 3-year ...
Full text: Production: This radio iodine produced by three methods: 1) Wet method: The irradiated tellurium is dissolved in an oxidizing mixture which also converts iodine in to iodide. This is a chemical method and iodine that it produced with this method has low purity and efficiency. 2). Dry Method: The irradiated tellurium is dissolved in furnace (750 deg. C) with sublimation method and iodine absorbed in sodium solution . In this case we have more than 99.5 % purity and 80 % efficiency. We are using this type in Iran. 3) Fission fragment method: In this case the iodine separated from fission fragment directly and we have high purity (career free) and specific activity of iodine. Application: Iodine is a versatile tracer element. It is used to determine thyroid cancer metastases, and size, shape and activity of the thyroid gland. Critical organ of iodine is thyroid gland. One of the common diagnostic procedures for determining thyroid function therefore, is to measure the ...
High quality "3"1P MR spectra (signal to noise ratio (S/N) approximately 18, 15 min acquisition for each spectrum) were consistently obtained with surface coils over a period of 6-week RT. Both transient and steady state alterations in metabolites in response to RT were found in this case. The transient changes occurred during the first 3 hr immediately after the 3rd fractionated RT, these changes include the transient elevation of the PCr resonance, a decrease in PDE and an increase in intracellular pH. The monitoring showed that the metabolites approached steady state approximately 2 hr after the fractionated radiation intervention, suggesting that in vivo MRS can be useful for studying the dynamics of tumor response to RT such as repair of potential lethal damage, growth delay, and reoxygenation etc. The steady-state MR spectra showed the net response to each intervention and can clinically be useful for predicting and measuring the result of the fractionated ...
The Anisotropic Analytical Algorithm (AAA) is a new pencil beam convolution/superposition algorithm proposed by Varian for photon dose calculations. The configuration of AAA depends on linear accelerator design and specifications. The purpose of this study was to investigate the accuracy of AAA for an Elekta SL25 linear accelerator for small fields and intensity modulated radiationtherapy (IMRT) treatments in inhomogeneous media. The accuracy of AAA was evaluated in two studies. First, AAA was compared both with Monte Carlo (MC) and the measurements in an inhomogeneous phantom simulating lung equivalent tissues and bone ribs. The algorithm was tested under lateral electronic disequilibrium conditions, using small fields (2x2 cm"2). Good agreement was generally achieved for depth dose and profiles, with deviations generally below 3% in lung inhomogeneities and below 5% at interfaces. However, the effects of attenuation and scattering close to ...
From 1977 through 1984, 293 previously untreated patients with biopsy proven carcinoma of the uterine cervix were treated by whole pelvis irradiation and high intensity 60Co remote afterloading (RAL) intrauterine tandem techniques in Haiti. The treatment results were analyzed retrospectively to evaluate the therapeutic results and prognostic factors of a strict protocol involving 40 Gy to the whole pelvis (2 Gy/day, 5 days/week). In addition, on the 5th day of the 3rd week, the first outpatient 60Co remote afterloading intracavitary insertion, delivering 7.5 Gy to point A with each insertion, repeated 3 times by a week separation for a total of 4 times. The total TDF for external beam plus RAL was 158 and 175 for early and late effects respectively. One hundred-four patients were evaluable after 1 year or more follow-up, with a median of 26.5 months. No evidence of disease (NED) by Stage at 1 year was: Stage I of 100% (3/3), Stage II of 82% (9/11), Stage III of 80% (47/59), and Stage ...
The OASIS Registry started annual collection of longitudinal data on patients on home parenteral nutrition (HPN) in 1984. This report describes outcome profiles on 1594 HPN patients in seven disease categories. Analysis showed clinical outcome was principally a reflection of the underlying diagnosis. Patients with Crohn's disease, ischemic bowel disease, motility disorders, radiation enteritis, and congenital bowel dysfunction all had a fairly long-term clinical outcome, whereas those with active cancer and acquired immunodeficiency syndrome (AIDS) had a short-term outcome. The long-term group had a 3-year survival rate of 65 to 80%, they averaged 2.6 complications requiring hospitalization per year, and 49% experienced complete rehabilitation. The short-term group had a mean survival of 6 months; they averaged 4.6 complications per year and about 15% experienced complete rehabilitation. The registry data also indicated HPN was used for 19,700 patients in 1987 with ...
The convolution/superposition algorithm for computing dose from photon beams in radiationtherapy planning requires knowledge of the energy spectrum. The algorithm can compute the dose for a polyenergetic beam as the weighted sum of the individual dose contributions from monoenergetic beams. In this study we exploit interface effects apparent in the dose distributions to discriminate among spectra of high energy photon beams. We have studied the sensitivity of the depth dose distribution to the energy components using a hypothetical beam for various field sizes and depths in water and water-lung-water media. Six theoretical spectra were simulated. We compared depth dose data from these spectra using three quantitative measures which are inherently free of normalization ambiguities: for homogeneous water, the ratio D_2_0/D_1_0 and a logarithmic derivative in the buildup region LD_b_u_i_l_d_-_u_p and for inhomogeneous lung/water, the lung ...
The effects of extended source-to-surface distance (SSD) on the electron beam dose profiles were evaluated for various electron beam energies - 6, 9, 12, 15 and 20 MeV - and the accuracy of various output correction methods was analysed on a Mitsubishi linear accelerator using a radiation field analyser (RFA). The dose fall-off region of the central axis depth-dose curves was nearly independent for SSDs up to 120 cm where as in the build-up region, a marginal reduction of surface dose was observed, particularly for lower energies and for smaller field sizes. Effective SSDs and virtual source distances were evaluated for field sizes ranging from 5x5 to 15x15 cm"2 for various energies. Curve fitting was done with the measured outputs with various equations and coefficients were evaluated. The accuracy of the derived output correction factors by effective SSD, virtual source distance and curve-fit methods was assessed by evaluating correlation coefficients between the ...
The number of multislice CT (MSCT) scans performed in polytraumatized children has increased rapidly. There is growing concern regarding the radiation dose in MSCT and its long-term consequences, especially in children. To determine the effective dose to polytraumatized children who undergo whole-body MSCT. A total of 51 traumatized children aged 0-16 years underwent a polytrauma protocol CT scan between November 2004 and August 2006 at our institution. The effective dose was calculated retrospectively by a computer program (CT-Expo 1.5, Hannover, Germany). The mean effective dose was 20.8 mSv (range 8.6-48.9 mSv, SD{+-}7.9 mSv). There was no statistically significant difference in the effective dose between male and female patients. Whole-body MSCT is a superior diagnostic tool in polytraumatized children with 20.8 mSv per patient being a justified mean effective dose. In a potentially life-threatening situation whole-body MSCT provides the clinicians with ...
Cervix cancer is the most common female cancer in Korea. In spite of their relatively local invasive tendency, still 44% of patient will develop recurrent cancer This result suggests that more aggressive local treatment may increase the cure rate but increased complication risk also cannot be avoidable. Various institutions proposed different treatment regimen, but recommended dose were about 4500 cGy for whole pelvis and 8000 cGy at point A, even though they agreed that those doses may not be satisfactory for control of bulky disease. 96 cases of invasive cervical cancer, treated with postoperative or primary radiationtherapy were analyzed to determine the complication rate and prognostic factor in our treatment regimen which is 500-1000 cGy higher than other institution. Mean follow up duration was 21 months. Symptomatic patients including mild but persistent abdominal discomfort was 46%, but only 1 patient (1%) had operative treatment ...
A new leaf-sequencing approach has been developed that is designed to reduce the number of required beam segments for step-and-shoot intensity modulated radiationtherapy (IMRT). This approach to leaf sequencing is called continuous-intensity-map-optimization (CIMO). Using a simulated annealing algorithm, CIMO seeks to minimize differences between the optimized and sequenced intensity maps. Two distinguishing features of the CIMO algorithm are (1) CIMO does not require that each optimized intensity map be clustered into discrete levels and (2) CIMO is not rule-based but rather simultaneously optimizes both the aperture shapes and weights. To test the CIMO algorithm, ten IMRT patient cases were selected (four head-and-neck, two pancreas, two prostate, one brain, and one pelvis). For each case, the optimized intensity maps were extracted from the Pinnacle"3 treatment planning system. The CIMO algorithm was applied, and the optimized aperture ...
Plutonium isotopes (239Pu and 238Pu, and 241Am) with a total activity of 269 kBq were accidentally deposited in a puncture wound of the right index finger of a nuclear worker at the Mayak Production Association. Tissues surrounding the wound site contaminated with radionuclides were excised 4.5 h after the injury. Residual contamination within the wound amounted to 0.05% of the initial contamination. The 10-d therapy with CaNa3-diethylene triamine pentaacetate acid (CaNa3-DTPA) was performed in parallel with in vivo measurements of the wound site and daily urine bioassays. The wound intake of radionuclides was consistent with two forms of radioactive materials detected within the wound site, i.e., soluble compounds and a large fragment, which was completely removed by excision. On day 9 after the injury, the clearance rate from the wound site was 1.8 times higher than the rate predicted by the National Council on Radiation Protection and ...
The object of this paper is to identify the key elements that impact a radiation dose at EAB (Exclusion Area Boundary). This study is based on the AST (Alternative Source Terms) as defined in Regulatory Guide 1.183. The LOCA (Loss of Coolant Accident) and the LRA (Locked Rotor Accident) are selected as limiting cases. A sensitivity analysis of accidental behavior with respect to various parameters during LOCA and LRA at Kori Unit 1 is also undertaken for the following objectives: to determine the limiting parameters, to find the impact trend of the radiation dose, and to find the safety margin between AST and TID (Technical Information Document) methodologies. This work confirms that key parameters are particulate removal rate, decontamination factor, iodine chemical form, gap fraction, partitioning factor, and the impact of isotopes group. Comparing TID with AST, the radiation dose of TID is about 80% greater than that of ...
The sterile insect release technique can often be improved by removal of females before release. Rearing efficiencies can also be increased if removal of the females occurs at early developmental stages. In order to begin to develop genetic sexing strains for the pink bollworm, Pectinophora gossypiella (Saunders), it was necessary to determine the best dosage of radiation for induction of viable sex linked recessive lethal mutations and to see if stocks containing induced sex linked lethals could be maintained in culture. Sex linked recessive lethal mutations can be detected by distorted sex ratios in the progeny of treated adults. However, in the pink bollworm, highly distorted sex ratios are common even in the absence of induced mutations. Therefore, a visible sex linked trait, purple eye, was used as a marker for the untreated X-chromosomes in crosses. Thus, the presence of a recessive sex linked lethal mutation induced by the radiation ...
Patients with Ewing's sarcoma who present with a central axis or proximal extremity primary and/or with metastatic disease have a poor prognosis despite aggressive combination chemotherapy and local irradiation. In this high risk group of patients, total body irradiation (TBI) has been proposed as a systemic adjuvant. To aid in the design of a clinical TBI protocol, the authors have studied in the in vitro radiation response of two established cell lines of Ewing's sarcoma and human bone marrow CFUc. The Ewing's lines showed a larger D_0 and anti-n compared to the bone marrow CFU. No repair of potentially lethal radiation damage (PLDR) was found after 4.5 Gy in plateau phase Ewing's sarcoma cells. A theoretical split dose survival curve for both the Ewing's sarcoma lines and human bone marrow CFUc using this TBI schedule shows a significantly lower surviving fraction (10"-"4-10"-"5) for the bone marrow CFUc. Based on these ...
Our objective was to evaluate the feasibility of ultra-low-dose scanning for multislice CT colonography in the detection of colorectal lesions. Twenty-seven patients (14 men, 13 women) with clinical indication for conventional colonoscopy were recruited. Multislice spiral CT (Somatom Plus 4 Volume Zoom, Siemens, Germany) examinations were performed after standard oral colonoscopic preparation and colonic distension with room air. Images were acquired using 2.5-mm collimation, 3.0-mm slice thickness, standard reconstruction kernel, 140 kVp, and 10 mAs. Supine and prone acquisitions were obtained in all patients. Images were analyzed on a workstation by two gastrointestinal radiologists. Conventional colonoscopy was performed on the same day in all patients and represented the standard of reference. Total radiation exposure was also calculated. All colorectal cancers were correctly identified at CT colonography (9 of 9, sensitivity 100%). The CT colonography also ...
Radiation exposure of members of the public can be increased appreciably by the use of building materials containing above-normal levels of natural radioactivity. This phenomenon has attracted attention in recent years, and in this review, an attempt is made to the quantify exposures incurred under various circumstances. The second section of the review is a general survey of those building materials, mostly industrial wastes, that have aroused interest in Member countries. The probability that environmental pressures may cause such wastes to be used more and more by building industries may lead to similar situations in the future. Other review material of a relevant nature is described in the third section. Primordial radionuclides only are considered here. They are: potassium-40 (K-40); radium-226 (Ra-226) and its decay products; the series headed by thorium-232 (Th-232). The important radiological consequences of the natural radioactivity in building materials ...
Purpose: To report on the nephron-sparing, percutaneous ablation of a large renal cell carcinoma by combined superselective embolization and percutaneous radiofrequency ablation. Materials and Methods: A 5 cm renal cell carcinoma of a 43-year-old drug abusing male with serologically proven HIV, hepatitis B and C infection, who refused surgery, was superselectively embolized using microspheres (size: 500 - 700 {mu}m) and a platinum coil under local anesthesia. Percutaneous radiofrequency ablation using a 7F LeVeen probe (size of expanded probe tip: 40 mm) and a 200 Watt generator was performed one day after transcatheter embolization under general anesthesia. Results: The combined treatment resulted in complete destruction of the tumor without relevant damage of the surrounding healthy renal tissue. The patient was discharged 24 hours after RF ablation. No complications like urinary leaks or fistulas were observed and follow up CT one day and 4 ...
Innovative therapy may appear to coincide with medical experimentation, raising ethical and legal issues, for instance on informed consent and institutional review. Medical treatments may be classified,...Full Text Available
Background and ObjectivePulsed dye laser (PDL) treatment of cutaneous vascular lesions is associated with variable and unpredictable efficacy. Thus, alternative treatment...Full Text Available
Objectives: Acupuncture has served as a major complementary and alternative therapy that supplements conventional medicine and is the subject of growing public interest. This study was conducted to estimate the usage rate of acupuncture as a supplemental treatment in acute ischaemic stroke patients and to identify factors associated with the choice to use this therapy. Methods: Using the registry of stroke patients admitted to an academic medical centre in Korea, the use of acupuncture therapy was recorded and analysed, along with the patients' socio-demographic characteristics, hospital access variables, risk factors for ischaemic stroke and clinical characteristics. The data were analysed using descriptive statistics, chi-square tests and multiple logistic regression analyses. Results: O...
Mycosis fungoides (MF) in deep-seated lymph nodes, spleen or liver appears to be associated with a lack of response of the disease to topical external therapy. Fourteen patients with mycosis fungoides...Full Text Available
Structured abstractObjectiveAlthough most reviews of Pseudomonas aeruginosa therapeutics focus on antibiotics currently in use or...Full Text Available
The success of monoclonal antibodies in clinical practice is dependent on good design. Finding a suitable target is the most important part as other properties of the antibody can be altered by genetic...Full Text Available
Penile rehabilitation therapy following radical prostatectomy is a much debated topic. Erectile dysfunction is still a significant contributor to postoperative morbidity following radical prostatectomy, despite meticulous nerve-sparing technique. Secondary smooth muscle changes in the penis have been identified as the underlying causes of penile atrophy, veno-occlusive dysfunction, and fibrosis. Initial observations that intracavernous injection therapies used on a regular basis postoperatively resulted in improvements in the return of spontaneous erectile function led to the development of penile rehabilitation protocols. Chronic dosing of PDE-V inhibitors is now commonly used by urologists after radical prostatectomy. Despite the current enthusiasm of penile rehabilitation therapy, current scientific evidence with clinical trials is still limited. PMID:19255627
PurposeTo identify the extent of persistence (period of time of continuous therapy with the drug prescribed) of glaucoma patients treated with prostaglandins (latanoprost, bimatoprost,...Full Text Available
BackgroundStump and phantom pains are debilitating sequelae of amputations that are often resistant to treatment. The efficacy of pharmacologic therapies, including...Full Text Available
BackgroundLymphangioleiomyomatosis (LAM) is a rare lung disease characterised by progressive airflow obstruction. No effective medical treatment is available but therapy with sirolimus...Full Text Available
SYNOPSISPreterm infants are at risk for both iron deficiency and iron overload. The role of iron in multiple organ functions suggests that iron supplementation is essential for...Full Text Available
Hyperglycemia frequently occurs with acute medical illness, especially among patients with cardiovascular disease, and has been linked to increased morbidity and mortality in critically ill patients....Full Text Available
Invasive fungal infections can be devastating, particularly in immunocompromised patients, and difficult to treat with systemic drugs. Furthermore, systemic administration of those medications...Full Text Available
An elderly man receiving chlorambucil for chronic lymphatic leukaemia developed focal fits. The onset and frequency were dose related. There was no evidence of metabolic disturbance or of meningeal...Full Text Available
The potential of radiolabelled phenylpiperazines as agents for the detection and therapy of tumours of neural crest origin was evaluated by in vitro pharmacological studies with human neuroblastoma...Full Text Available
BackgroundTo investigate the effects of intravenous lignocaine infusions (IV lignocaine) in fibromyalgia.MethodsProspective study...Full Text Available
SynopsisAttention-deficit / hyperactivity disorder (ADHD) is a valid and impairing psychological disorder that persists into adulthood in a majority of cases and is associated...Full Text Available
BackgroundAlthough advances in rehydration therapy have made cholera a treatable disease with low case-fatality in settings with appropriate medical care, cholera continues...Full Text Available
... mammography or on ultrasound but not found on physical examination, we consider them non-palpable or not ... lot of this. We send every patient for physical therapy, no matter what type of reconstruction we ...
Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal...Full Text Available
BackgroundAdequate pain assessment is critical for evaluating the efficacy of analgesic treatment in clinical practice and during the development of new therapies. Yet the currently...Full Text Available
Methods: Systemic irradiation of neuroaxis is an essential part in the management of medulloblastoma, stPNET and intracranial germ cell tumors. The introduction of quality assurance programs in radiooncology assures a precise radiotherapy of target volumes and is a prerequisite to improve survival. Results: Hyperfractionated radiotherapy has the potential of increasing dose to tumor more safely without increasing the risk for late adverse effects. Pilot studies revealed excellent tumor control in medulloblastoma with acceptable acute toxicity and a long-term survival of up to 96%. In medulloblastoma stereotactic radiation techniques reveal an acceptable toxicity and promising results in tumor control in recurrent disease or as primary treatment. They are now part of future treatment protocols in case of persisting residual tumor. Radiotherapy alone in pure germinoma is continuously yielding high cure rates. In secreting germ cell tumors cisplatin containing ...
Objective: To develop a computerized method of internal dose estimation on radiation protection. Methods: Based on MIRD mathematic model of the organs and by means of the programming language of MS Visual Basic 6.0, a computer program of dose estimation in internal radiation was developed for radiation protection. Results: The computerized method of dose estimation for internal radiation was completed. Conclusions: This computerized method is very convenient for internal radiation dose estimation of several aspects. It can also be used in radiation accident. (authors)
Purpose/Objective: At present, treatment verification between portal and reference images is performed based on manually-identified features by radiation oncologist, which is both time-consuming and potentially error-prone. There is a demand for the computerized verification procedure in clinical application. The purpose of this study is to develop a computerized portal verification scheme for pelvic treatment fields. Materials/Methods: The automated verification system involves image acquisition, image feature extraction, feature matching between reference and portal images and quantitative evaluation of patient setup. Electronic portal images with a matrix size of 256 x 256 and 12 bit gray levels were acquired using a liquid matrix electronic portal imaging device. Simulation images were acquired by digitizing simulation films using a TV camera into images with 256 x 256 matrix and 8 bit gray levels. Initially a Canny edge detector is applied to identify the ...
Full text: As you know, thin films which generate anomalous big photovoltage (APhV) , as film photo resistive structures made of the combinations of A_2B_6 respond to X-ray and #gamma#- radiations. In this work the influence of X-ray and #gamma#-radiations on the quantity of APhV in the system APhV-film-photoresistor was investigated. Earlier polycrystal films with anomalous photo voltage properties were received only on the clean and flat surface with high isolation property (R>10"1"4 #OMEGA#). We worked out the technology of receiving APhV films CdTe on the surface of the photosensitive film CdS. The main condition under which this effect may be observed is that the lining must be slant concerning to the direction of the motion of evaporated substance's molecular bunch during the growing of the film, i.e. received film must have a dendritic structure. That is why photosensitive film CdS was received with thermo vacuum ...
German translation of the publication 'The evaluation of risks from radiation' published in 1965 by the International Commission on Radiological Protection. In a survey, genetic and somatic risks from radiation are presented and explained. (HP).
This book gives an overview of the entire field of radiation protection with the subject areas radioactivity, X-rays, UV radiation, laser beams and high-frequency electromagnetic fields. It deals graphically with the most important physical notions, the incidence, origin, properties and biological effects of types of radiation, administrative and practical protection measures and the code of rules governing them. Apart from fundamentals of radiation protection the emphasis on the following: natural radiation exposure, radiation exposure to radon, disaster relief plans in the environment of nuclear plant, the precautionary radiation protection system evolved after Chernobyl, radiation exposure through UV radiation devices, radio, RF communication, radar, microwave ovens and high-voltage transmission ...