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 car...

the monte carlo method can be used to describe any technique that approximates solutions to quantitative problems through statistical sampling. this method is considered to be the most accurate method for dose calculation in radiotherapy. for complete modeling of a linear accelerator, it is required that the manufactured information covers all data, but some data such as primary electron energy...

Introduction: Treatment with megavoltage electron beams is ideal for irradiating superficial tumors because of their limited range in tissues. However, for electron treatment of extended areas, such as the chest wall, two or more adjacent fields can be used. Abutment of these fields may lead to significant dose in homogeneities in the junction region. The aim of this study is to offer a new met...

OBJECTIVE Development of a technique for treating whole-body skin using linear accelerator with electron beam energy of 6-MeV at a short treatment distance. MATERIAL AND METHODS The 6 MeV high dose rate total skin electron irradiation mode on a linear accelerator was used. Beam profiles and percentage depth doses in the patient plane were measured for different beam angulations. RESULTS At ...

Introduction: In clinical electron beams, most of bremsstrahlung radiation is produced by various linac head structures. This bremsstrahlung radiation dose is influenced by the geometry and construction of every component of the linac treatment head structures. Thus, it can be expected that the amount of the contaminated photon dose due to bremsstrahlung radiation varies among different linacs,...

background: one of the main problems of dedicated iort accelerators is to determine dosimetric characteristics of the electron beams. monte carlo simulation of iort accelerator head and produced beam will be useful to improve the accuracy of beam dosimetry. materials and methods: liac accelerator head was modeled using the beamnrcmonte carlo simulation system. phase-space files were generated a...

Introduction: Intraoperative radiotherapy is a radiotherapy technique in which a high single fraction of radiation dose is delivered to the patient after surgery and Concurrent with anesthesia time. The most frequent method for IORT implementation is Intraoperative electron radiotherapy (IOERT), in which, some dedicated and high dose per pulse electron accelerators are employe...

Stability of electron orbit is one of the most important properties to achieve brilliant photon beams for third generation synchrotron radiation sources. In the design of a SPring-8 storage ring, many ideas for orbit stabilization were thus considered. Consequently, without any correction, electron orbit stability of about 50 μm per day is obtained. Since a main part of the orbit movement is sl...

modification of the mechanical properties of silicone rubber were considered for drug delivery systems by using high-energy electron beam (e-beam). in this research work, two different medical grades of silicone rubbers were used to prepare matrices containing 10wt% progesterone with 2 mm thickness and irradiated with e-beam at dose range of 25 up to 200 kgy. then, the mechanical properties as ...