Peyman Hejazi
Medical Physics Dept., Semnan University of Medical Sciences, Semnan, Iran
[ 1 ] - Optimization of Parameters in 16-slice CT-scan Protocols for Reduction of the Absorbed Dose
Introduction In computed tomography (CT) technology, an optimal radiation dose can be achieved via changing radiation parameters such as mA, pitch factor, rotation time and tube voltage (kVp) for diagnostic images. Materials and Methods In this study, the brain, abdomen, and thorax scaning was performed using Toshiba 16-slice scannerand standard AAPM and CTDI phantoms. AAPM phantom was used for...
[ 2 ] - Quality Control of Radiography Equipments in Golestan Province of IRAN
Introduction The main goal of this study was to perform quality control test on all radiography units operating in Golestan province of IRAN. Materials and Methods Forty-four X-ray units were examined based on general accepted programs for quality control. Eight parameters including kVp accuracy, kVp reproducibility, mA-time reciprocity, exposure linearity, exposure reproducibility, timer accur...
[ 3 ] - Influence of Compensator Thickness and Field Size on Buildup factor of a Brass Compensator for Intensity- Modulated Radiation Therapy
Introduction: Radiotherapy is one of the effective methods in the treatment of cancer. In the recent methods of radiotherapy, intensity modulated radiotherapy (IMRT) technique by compensators is used. when photon beam passes the compensator, scattered photons can be generated within the compensator. The presence of scattered photons may complicate the design of compensators as...
[ 4 ] - Statistical uncertainty estimation in the calculation of the proton range in water phantom.
Introduction: GATE (Geant4 Application for Tomographic Emission) is a Monte Carlo simulation platform developed by the OpenGATE collaboration since 2001 and first publicly released in 2004. In Geant4, each physics process is described by a model (several models are sometimes available for a given physics process) and a corresponding cross-section table. All Geant4 physics model...
[ 5 ] - The Influence of Brass Compensator Thickness and Field Size on Neutron Contamination Spectrum in 18MV Elekta SL 75/25 Medical Linear Accelerator with and without Flattening Filter: A Monte Carlo Study
BackgroundOne of the most significant Intensity Modulated Radiation Therapy treatment benefits is a high target to normal tissue dose ratio. To improve this advantage, an additional accessory such as a compensator is used to delivering doses. Compensator-based IMRT treatment is usually operated with an energy higher than 10 MV. Photoneutrons, which have high linear energy transfer and radiobiol...
[ 6 ] - Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method
Background: Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions.Objective: The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiothe...