Background: Multiple beams are generally used with an increased possibility that the beam axis intersects the treatment table. Treatment tabletops are commonly made of carbon fiber due to its high mechanical strength and rigidity, low specific density, extremely light and low radiation beam attenuation properties. Purpose of this paper is investigated the dose changes in the buildup region and ...

Introduction: Receiving exact dose by the patients is vital in radiotherapy. In radiation therapy, the dosimetry of radiations is too important because of successful radiation inquires for delivering the exact dose to the target volume. This study is to evaluate the tolerances and the accuracy of calculated dose of photon beams in the treatment software system. The TECDOC1583 p...

Introduction: Today, radiotherapy combined with surgery in the treatment of parotid tumors widely are used specially for high grade parotid tumors. One of concern and challenge issue of radiotherapy is that the treatment of these tumors with irregular surface due to the presence of external ear and region of different physical electron density (air cavities, dense bone, soft t...

Background: The International Commission on Radiological Protection (ICRP) has attributed the same relative risk for X and gamma radiations of all energies. Several studies have proven that the biological effect of low energy photon is more than that of higher ones. The assessment of risks is important due to the wide use of low energy X-rays for mammography screening and other diagnostic appli...

Background: In this work investigation of the normoxic PAGAT polymer gel dosimeter such as sensitivity, the R2-dose response with post time and the percentage depth dose (PDD) of PAGAT polymer gel dosimeter have been undertaken. Materials and Methods: Using MRI, the formulation to give the maximum change in the transverse relaxation rate R2 was determined to be 4.5% N,N'-methylenbis- ...

Boron neutron capture therapy (BNCT) is a form of chemically targeted radiotherapy that utilises the high neutron capture cross-section of boron-10 isotope to achieve a preferential dose increase in the tumour. The BNCT dosimetry poses a special challenge as the radiation dose absorbed by the irradiated tissues consists of several dose components with different relative biological effectiveness...

ntroduction:  monte  carlo  simulation  is  the  most  accurate  method  of  simulating  radiation  transport  and  predicting doses at different points of interest in radiotherapy. a great advantage of the monte carlo method  compared  to  the  deterministic  methods  is  the  ability  to  deal  accurately  with  any  complex  geometry.  its  disadvantage is the extremely long computing time r...