introduction: secondary radiation such as photoelectrons, auger electrons and characteristic radiations cause a local boost in dose for a tumor when irradiated with an external x-ray beam after being loaded with elements capable of activating the tumor, e.g.; i and gd. materials and methods:  in this investigation, the mcnpx code was used for simulation and calculation of dose enhancement facto...

background: to enhance the dose to tumor, the use of high atomic number elements has been proposed. objective: the aim of this study is to investigate the effect of gold nanoparticle distribution on dose enhancement in tumor when the tumor is irradiated by typical monoenergetic x-ray beams by considering homogeneous and inhomogeneous distributions of gold nanoparticles (gnps) in the tumor. meth...

Introduction: Paediatric patients deserve special attention because of the higher radiation risks compared with adults. The main purpose of this study is to determine patient dose and diagnostic reference level for Paediatric through Entrance Surface Dose (ESD) calculations in common X-ray examination and to establish Paediatric national DRLs in digital radiography in Iran. <...

Introduction: Average glandular dose calculation in mammography with Mo-Rh target-filter and dose calculation for different situations is accurate and fast. Material and Methods: In this research, first of all, x-ray spectra of a Mo target bombarded by a 28 keV electron beam with and without a Rh filter were calculated using the MCNP code. Then, we used the Sobol-Wu parameters to write a FORTRA...

Introduction: Secondary radiation such as photoelectrons, Auger electrons and characteristic radiations cause a local boost in dose for a tumor when irradiated with an external X-ray beam after being loaded with elements capable of activating the tumor, e.g.; I and Gd. Materials and Methods:  In this investigation, the MCNPX code was used for simulation and calculation of dose enhancement facto...

Background: This study aims to calculate the air-kerma strength (SK), the dose rate constant (&and;) and the dose rate profiles of a Gammamed 12i Ir-192 source by using the Monte Carlo technique and to compare the dose rate values with those calculated by the Abacus HDR treatment planning system (TPS). Materials and Methods: Air-kerma strength (in units of U; 1 U= &mu;Gy m2 h-1) and the dose ra...