Introduction: This study investigates basic dosimetric properties of unflattened 6 MV photon beam shaped by multileaf collimator and compares them with those of flattened beams.Materials and Methods: Monte Carlo simulation model using BEAM code was developed for a 6MV photon beam based on Varian Clinic 600 unique performance linac operated with and without a flattening filter in beam line. Dosi...

background: because of the adverse effects of ionizing radiation on fetuses, prior to radiotherapy of pregnant patients, fetal dose should be estimated. fetal dose has been studied by several authors in different depths in phantoms with various abdomen thicknesses (at). in this study, the effect of maternal at and depth in fetal dosimetry was investigated, using peripheral dose (pd) distributio...

Background and purpose: Audit is imperative in delivering consistent and safe radiotherapy and the UK has a strong history of radiotherapy audit. The National Physical Laboratory (NPL) has undertaken audit measurements since 1994 and this work examines results from these audits. Materials and methods: This paper reviews audit results from 209 separate beams from 82 on-site visits to National He...

background: the electron contamination may reduce or even diminish the skin sparing property of the megavoltage beam. the detailed characteristics of contaminant electrons are presented for different field sizes and cases. materials and methods: the monte carlo code, mcnpx, has been used to simulate 18 mv photon beam from a varian linac-2300 accelerator. all dose measurements were carried out u...

background: this study assessed the clinical usefulness of the solid phantom, which may compensate for the disadvantages of the water phantom, by comparing the radiological doses between the two depending on their depths. materials and methods: the experimental equipment used was a linear accelerator for medical use, water phantom, solid phantom, farmer type ion chamber and electrometer. the di...

Objective(s): In this study we evaluate the impact of the different aspects of Gold Nano-Particles (GNPs) on the target absorptive Dose Enhancement Factor (DEF) during external targeted radiotherapy with photon beams ranging from kilovolt to megavolt energies using Monte Carlo simulation. Methods: We have simulated the interaction of photon beams wi...

These experiments compare the out-of-field dose delivered during different treatment techniques (photons, active and passive delivered protons and carbon ions) in standardized conditions. A water phantom is used as tissueequivalent material and is irradiated with a rectangular field. The dose is measured in lateral direction in the plane of the field as shown in Fig. 1. The composition of the o...

  Introduction: This study aimed to report the measurement of photon and electron beams to configure the Analytical Anisotropic Algorithm and Electron Monte Carlo used in clinical treatment. Material and Methods: All measurements were performed in a large water phantom using a 3-dimensional scanning system (PTW, Germany). ...