Objectives: Developing an optimal Stereotactic radiosurgery (SRS) plan for multiple brain metastases can be a labor intensive process. Single-isocenter multi-arc volumetrically modulated arc therapy (VMAT) has been used as an SRS technique, in which a Linear Accelerator (Linac) delivers targeted radiation along multiple arc angles as it rotates around the isocenter. Standardized arc angles with...

Multileaf collimator (MLC) calibration and quality control is a time-consuming procedure typically involving the processing, scanning and analysis of films to measure leaf and collimator positions. Faster and more reliable calibration procedures are required for these tasks, especially with the introduction of intensity modulated radiotherapy which requires more frequent checking and finer posi...

Introduction: This study investigates basic dosimetric properties of unflattened 6 MV photon beam shaped by multileaf collimator and compares them with those of flattened beams.Materials and Methods: Monte Carlo simulation model using BEAM code was developed for a 6MV photon beam based on Varian Clinic 600 unique performance linac operated with and without a flattening filter in beam line. Dosi...

Introduction: Geometric changes in the multileaf collimator (MLC) led to dosimetric considerations in intensity-modulated radiation therapy (IMRT) due to the number and size of the pixels in the intensity map, which are determined by the MLC leaf width. In this study, we evaluated the dosimetric effects of different MLC widths on physical dose distributions for IMRT plans. Materials and Method...

Introduction: Multileaf collimator (MLC) is state of the art among the radiation field shaping systems for conformal radiotherapy techniques. Some advantages of this system are as follow: reduction of treatment time, higher precision in conforming the radiation field to the projection of the target volume and lowering the chance of errors made by technologists. The purpose of this research was ...

Cancer is one of the major causes of death all over the globe and radiotherapy is considered one of its most effective treatment methods. Designing a radiotherapy treatment plan was done entirely manually in the past. RecentlyIntensity Modulated Radiation Therapy (IMRT) was introduced as a new technology with advanced medical equipmentin the recent years. IMRT provides the opportunity to delive...

The synchronization of dynamic multileaf collimator (DMLC) response with respiratory motion is critical to ensure the accuracy of DMLC-based four dimensional (4D) radiation delivery. In practice, however, a finite time delay (response time) between the acquisition of tumor position and multileaf collimator response necessitates predictive models of respiratory tumor motion to synchronize radiat...