Introduction: Monte Carlo method is often applied in radiation therapy as utilized in all the branches of science. An important requirement for successful radiotherapy is carefully examine the dose distribution specifications and decrease the difference between these features with experience to an acceptable level. In this study, the characteristics of 6, 15 and 20 MeV incident x-rays are prov...

This paper investigates the accuracy of the two available calculation algorithms of the Oncentra MasterPlan three-dimensional treatment planning system (TPS)-- the pencil beam method and collapsed-cone convolution--in modeling the Varian enhanced dynamic wedge (EDW). Measurements were carried out for a dual high energy (6-15 MV) Varian DHX-S linear accelerator using ionization chambers for beam...

Introduction Magnetic fields are capable of altering the trajectory of electron beams andcan be used in radiation therapy.Theaim of this study was to produce regions with dose enhancement and reduction in the medium. Materials and Methods The NdFeB permanent magnets were arranged on the electron applicator in several configurations. Then, after the passage of the electron beams (9 and 15 MeV Va...

background: in the current study the effect of shielded colpostat on rectum received dose was calculated in cervical brachytherapy using monte carlo (mc) method. materials and methods: two 60co sources of gzp6 brachytherapy unit used for intracavitary treatments were simulated using mcnpx monte carlo code. also the two types of colpostats including shielded and unshielded were simulated inside ...

Aim: This study aims to evaluate the difference between depth data from an intraoral cone and a conventional irradiation tube calculated using a treatment planning system (TPS), and that measured using an intraoral cone for electron radiotherapy. Background: A TPS is only compatible with conventional irradiation tubes. However, such systems are not suitable for determining dose distributions wh...

geant4 is an open source simulation toolkit based on c++, which its advantages progressively lead to applications in research domains especially modeling the biological effects of ionizing radiation at the sub-cellular scale. however, it was shown that geant4 does not give a reasonable result in the prediction of antiproton dose especially in bragg peak. one of the reasons could be lack of a re...

Introduction: In radiotherapy, the bolus is often used while treating the tumor under the uneven surfaces of the patients for correcting the anatomical irregularities and increasing skin dose. Wet cotton and wet gauze are still used in developing countries, since the use of wet cotton and wet gauze has certain disadvantages, there is a need for transparent bolus which ...

background: megavoltage beams used in radiotherapy are contaminated with secondary electrons. different parts of linac head and air above patient act as a source of this contamination. this contamination can increase damage to skin and subcutaneous tissue during radiotherapy.  monte carlo simulation is an accurate method for dose calculation in medical dosimetry and has an important role in opt...