Introduction: This study was designed to evaluate dosimetric parameters such as rectal dose, bladder dose, integral dose (ID), homogeneity index (HI) and conformity index (CI) in various treatment plans for prostate cancer. Materials and Methods: Pelvic computed tomography (CT) scans of 27 patients were acquired and transferred to the RTDosePLAN treatment planning system. For each patient, 8 co...

background: natural background radiation of a particular region is one of the distinctive factors defining the status of environment. eloor island is an industrial area in ernakulum district of the state of kerala, india. the indoor and outdoor gamma level measurements have been carried out for the region for evaluating the annual effective dose to the population residing in this area. material...

For a start, although integral dose is generally assumed to be improved by the use of higher energy photons, there is concern that some treatment planning systems might not effectively model the “beam narrowing” at depth observed with high energy photons in the small radiation beamlets encountered in IMRT. This phenomenon is caused by lateral beam degradation due to penumbra widening (8); when ...

PURPOSE To introduce the concept of energy minimization-based inverse optimization for external beam radiotherapy. MATERIALS AND METHODS Mathematical formulation of energy minimization-based inverse optimization is presented. This mathematical representation is compared to the most commonly used dose-volume based formulation used in inverse optimization. A simple example on digitally created ...

Introduction: Iterative reconstruction techniques provide better image quality and have the potential for reconstructions with lower imaging dose than classical methods in computed tomography (CT). However, the computational speed is major concern for these iterative techniques. The system matrix calculation during the forward- and back projection is one of the most time- cons...

in this paper, we present an efficient method for determining the solution of the stochastic second kind volterra integral equations (svie) by using the taylor expansion method. this method transforms the svie to a linear stochastic ordinary differential equation which needs specified boundary conditions. for determining boundary conditions, we use the integration technique. this technique give...

Background : To assess feasibility of sparing the neural stem cell compartment (NSC), hippocampus, and limbic circuit during partial brain radiotherapy (PBRT) for pediatric intracranial tumors. Methods : Treatment plans were generated for the following pediatric intracranial tumors: low and high grade gliomas, low grade brainstem glioma, optic nerve glioma, hypothalamic glioma, localized ependy...