The cancer of oral cavity is related to lesions of mucous membrane of tongue and gum that can be treated with radiation therapy. A lateral photon field can be used to treat this kind of tumor, which has a side-effect on normal tissue in the opposite side of the oral cavity. In this study the dosimetric effect of the various shields in oral cavity is evaluated. In this study, a special phantom s...

normal 0 false false false en-us x-none fa introduction: in radiation therapy centers across iran, protection of normal tissues is usually accomplished by either cerrobend or lead block shielding. in this study, the influence of these two shielding methods on central axis dose distribution of photon beam a cobalt unit was investigated in clinical conditions. materials and methods: all measureme...

Introduction:In the nuclear medicine departments, staff exposure to radiation is inevitable during patient positioning and radiopharmaceutical preparation. There is controversy regarding the use of usual lead aprons with respect to penetrating gamma rays used in nuclear medicine departments as well as production of characteristic lead x-ray from aprons. Methods:</stron...

Photon ambient dose equivalent buildup factors were calculated for point and plaque isotropic cobalt-60 and cesium-137 radioactive sources irradiating a finite slab shield materials of ordinary concrete, barite concrete, lead, lead glass and water using MCNP5 code. Studied shield thickness ranged from 1 to 15 mean free paths (mfp). A variance reduction technique available in the code was used t...

Introduction Most of the nuclear imaging systems require the use of a gamma (γ)-ray radiation shield to attenuate a stream of γ-rays so that only those traveling in a specified direction are allowed through and to absorb the scattered γ-rays from out of interest regions [1-2]. To meet those requirements, a γ-ray radiation shield is usually made out of lead (Pb) or some other high Z material suc...

Introduction: Coronary angiography (CA) is an interventional diagnostic procedure to assess cardiovascular disease. CA is performed using dedicated fluoroscopic systems equipped with either flat detector or image intensifier. There is an increase in the number of CA annually. Reducing the radiation exposure in the CA is essential, especially due to high fluoroscopy time. In ord...