نتایج جستجو برای: brachytherapy gamma sources
تعداد نتایج: 415361 فیلتر نتایج به سال:
Recently, various linear source models, for example, 103Pd RadioCoil, have been introduced to overcome the shortcomings of traditional "seed" type interstitial prostate brachytherapy implants, such as migration and clumping of the seeds. However, the existing prostate treatment-planning systems have not been updated to perform dose calculation for implants with linear sources greater than 1.0 c...
The aim of the present study was to estimate the wall effect of the self-made spherical graphite-walled cavity chamber with the Monte Carlo method for establishing the air-kerma primary standard of high-dose-rate (HDR) ¹⁹²Ir brachytherapy sources at the Institute of Nuclear Energy Research (INER, Taiwan). The Monte Carlo method established in this paper was also employed to respectively simulat...
BACKGROUND Scarce data exist concerning the long-term effect of percutaneous transluminal renal angioplasty (PTRA) enhanced with intravascular gamma brachytherapy (IVBT) in patients with renovascular hypertension. METHODS Seventy one patients aged 52 +/- 8 years with refractory renovascular hypertension were randomized to Group I (PTRA + IVBT) or Group II (PTRA). For the IVBT procedure, the P...
Introduction: In brachytherapy, radioactive sources are placed close to the tumor, therefore, small changes in their positions can cause large changes in the dose distribution. This emphasizes the need for computerized treatment planning. The usual method for treatment planning of cervix brachytherapy uses conventional radiographs in the Manchester system. Nowadays, because of their advantages ...
Since the first days of angioplasty, restenosis has been the major limitation. Over the brief history of percutaneous interventions, therapies to prevent restenosis have come and gone with a frequency that rivals treatments for rheumatoid arthritis over the last hundred years. We have also learned to be skeptical regarding any claim of benefit from a therapy for established restenosis. In the r...
BACKGROUND Hypoxic human coronary smooth muscle cells (HCSMCs) are possible targets for brachytherapy to prevent restenosis after percutaneous transluminal coronary angiography. It is unclear whether growth kinetics and gene expression of these cells undergoing gamma-irradiation are changed by reoxygenation. METHODS AND RESULTS Hypoxic (H) and hypoxia-reoxygenated (H-R) HCSMCs were irradiated...
Monte Carlo simulations are widely used for calculation of the dosimetric parameters of brachytherapy sources. MCNP4C2, MCNP5, MCNPX, EGS4, EGSnrc, PTRAN, and GEANT4 are among the most commonly used codes in this field. Each of these codes utilizes a cross-sectional library for the purpose of simulating different elements and materials with complex chemical compositions. The accuracies of the f...
Low-dose rate brachytherapy has become a mainstream treatment option for men diagnosed with prostate cancer because of excellent long-term treatment outcomes in low-, intermediate-, and high-risk patients. To a great extend due to patient lead advocacy for minimally invasive treatment options, high-quality prostate implants have become widely available in the US, Europe, and Japan. High-dose-ra...
Brachytherapy, is a method to treat prostate cancer in which a radiation source is placed inside or next to the cancer affected tissues. Purpose of this article is to determine the uncertainty level of received dose in prostate tissue due to the relocation of the placed radiation sources and inflation in prostate after positioning the radiation seeds. To simulate the model 6711 Amersham (activi...
Background: Prompt gamma neutron activation analysis (PGNAA) is known as a non-invasive technique capable of measuring elemental concentration in voluminous samples in a short period of time. Also it is a valuable diagnostic tool for total body elemental measurements. 252Cf and 241Am-Be sources which are usually used in this method, generate not only neutrons, but also emit high-energy and unwa...
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