Objective: Using Megavoltage photons generated by medical linear accelerator is a common modality for the treatment of malignant. The crucial problem for using photon beams >8MV is the photoneutron yields that increase the risk of secondary cancer that treated with high-energy photon beams. The contaminated neutrons produced in different components of the accelerator head and rely on many param...

Introduction: In radiotherapy, methods of treatment planning are becoming increasingly more complicated. This requires verification of the doses delivered to increasingly smaller and more precise regions. Radiotherapy techniques are continuously employing smaller and smaller field sizes to deliver tighter radiation doses with higher therapeutic ratios, generating interest among researchers to p...

Purpose: In the last years, some studies investigated dosimetric benefits of a free flattening filter for the photon mode in the radiotherapy field. This study aims to provide a theoretical study published and analysis of basic dosimetric properties for a Saturne 43 Linac head to implement free flattening filter beams clinically. Material and Methods: Thi...

abstract background: adjacent treatment fields are commonly used in external beam radiation therapy, such as mantle and inverted-y fields for the treatment of hodgkin’s disease and craniospinal fields used in the treatment of medulloblastoma and head and neck tumors when the lateral neck fields are placed adjacent to the anterior supraclavicular field. in each of these situations, there is a po...

background: in order to deliver the precise dose to the target in radiotherapy, absorbed dose to water at the reference point should be assessed. when the calibration procedure is performed for a reference dosimeter in the 60co beam of a secondary standard dosimetry laboratory (ssdl), the total uncertainty in absorbed dose to water (dw) is estimated to be approximately 1.5%. this study attempts...

Background: Breast cancer is the most frequently diagnosed cancer and the leading global cause of cancer death among women worldwide. Radiotherapy plays a significant role in treatment of breast cancer and reduces locoregional recurrence and eventually improves survival. The treatment fields applied for breast cancer treatment include: tangential, axillary, supraclavicular and internal mammary ...

Background: Understanding of the incident electron energy and angular distributions from clinical electron accelerators (linacs) is important for dosimetry and treatment planning. The most important goals of this study were to evaluate the energy fluence and angular distributions of electron beams from a Neptun 10PC linac using the Monte Carlo (MC) code. Materials and Methods: The lina...

in order to compare effect of magnetic field and frigate surfactant to enhance the efficacy of iodosulfuron-methyl-sodium plus mesosulfuron-methyl (chevalier) to control wild oat, a greenhouse experiment of dose-response was conducted. treatments were 0, 3, 6, 12, 18 and 24 doses g a.i. ha-1 of chevalier (i) without treatment, (ii) with frigate % 0.1 v/v, (iii) with magnetic field, and (iv) fri...

This study provided baseline data required for a greater project, whose objective was to design a new Elekta electron collimation system having significantly lighter electron applicators with equally low out-of field leakage dose. Specifically, off-axis dose profiles for the electron collimation system of our uniquely configured Elekta Infinity accelerator with the MLCi2 treatment head were mea...

Background: The aim of present study was to analyze the effectiveness of electron filters in the Telecobalt radiotherapy treatment by simulation technique.  Materials and Methods: The BEAMnrc Monte Carlo code was used to simulate the electron filters of thickness of 0.5 gm/cm2 below the trimmer bar for 35 × 35 cm2 field size in Theratron Equinox-80 telecobalt unit. The electron filters were mad...