Background: In treating patients with radiation, the degree of accuracy for the delivery of tumor dose is recommended to be within ± 5% by ICRU in report 24. The experimental studies have shown that the presence of low-density inhomogeneity in areas such as the lung can lead to a greater than 30% change in the water dose data. Therefore, inhomogeneity corrections should be used in treatment pla...

ABSTRACT Background: accurate methods of radiation therapy dose calculation. There are different Monte Carlo codesfor simulation of photons, electrons and the coupled transport of electrons and photons. MCNPis a general purpose Monte Carlo code that can be used for electron, photon and coupledphoton-electron transport.Monte Carlo simulation of radiation transport is considered to be one of the ...

Introduction: 192Ir is one of the important sources frequently used in brachytherapy. Up to now, a lot of commercial models of this source have been made which Ir-192 has been recently added to them. The aim of the present study is to determine the dosimetric parameters of this new source model based on the recommendations of TG-43(U1) protocol using Monte Carlo simulation tech...

Introduction: Gamma Knife is an instrument specially designed for treating brain disorders. In Gamma Knife, there are 201 narrow beams of cobalt-60 sources that intersect at an isocenter point to treat brain tumors. The tumor is placed at the isocenter and is treated by the emitted gamma rays. Therefore, there is a high dose at this point and a low dose is delivered to the normal tissue surroun...

Theoretical and experimental dosimetric studies have been supplied useful information on the dependence of the brachytherapy source geometry and materials (1-5). Usually, Monte Carlo method is used to define dose distribution function, the radial dose variation, and the dose calculation close to the source in brachytherapy. Chen et al. (6). calculated the distribution of absorbed dose around co...

BACKGROUND The old Treatment Planning Systems (TPSs) used for intracavitary brachytherapy with Cs-137 Selectron source utilize traditional dose calculation methods, considering each source as a point source. Using such methods introduces significant errors in dose estimation. As of 1995, TG-43 is used as the main dose calculation formalism in treatment TPSs. OBJECTIVES The purpose of this stu...

Background: The Monte Carlo (MC) method is not only used for dose calculations around brachytherapy sources but also for benchmarking treatment planning systems (TPS) calculations. Materials and Methods: Three 60Co sources of GZP6 brachytherapy unit were simulated using MCNP4C MC Code. The radial dose functions were calculated by MC method and GZP6 TPS and were compared. Results: There was a go...