Objective: Different categories are available for estimating of radiation dose. Radioisotopes with the same energy and almost the same physical properties have similar effects. Monte Carlo technique is a computerized method based on mathematical simulation of physical processes. The main purpose of this study is to show that beta particles are not able to penetrate deep into the water. also dif...

Background: HDR brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. In this method, depending on how advanced one tumor is, 2 to 6 Gy dose as intracavitary brachytherapy is prescribed. Due to high dose rate and tumor location, accuracy evaluation of treatment planning system (TPS) is particularly important. Common methods used in TPS dosimetry are based on computat...

In this paper, we present a novel implementation of a dose calculation application, based on the GEANT4 Monte Carlo toolkit. Validation studies were performed with an homogeneous water phantom and an Alderson-Rando anthropomorphic phantom both irradiated with high-energy photon beams produced by a clinical linear accelerator. As input, this tool requires computer tomography images for automatic...

In this paper, a new approach for haptic rendering of high resolution voxel-based anatomic models is presented. For visualization the surface location is determined by a ray-casting algorithm at sub-voxel resolution. Since the same algorithm is used for the haptics as well, a very high level of detail is achieved for haptic feedback. Both graphical and haptic representation is congruent. The in...

introduction: gafchromic ebt films are one of the self-developing and modern films commercially available for dosimetric verification of treatment planning systems (tpss). their high spatial resolution, low energy dependence and near-tissue equivalence make them suitable for verification of dose distributions in radiation therapy. this study was designed to evaluate the dosimetric parameters of...

Introduction: Dynamic and 4D MRI have been used to understand the functional and metabolic aspects of disease and its progression. Examples include dynamic contrast enhancement (DCE) for micro-vasculature of tumors and MR spectroscopic imaging (MRSI) for tissue bio-chemistry. The post-processing strategy for most of these protocols consists of obtaining parametric maps using voxel-by-voxel esti...

The aim of this study is to evaluate the impact of a high resolution (HR) image reconstruction with a voxel size of 2mm in comparison to the most routinely used standard reconstruction with 4mm voxels in patients suffering from prostate cancer having undergone (18)F-methylcholine PET/CT. Phantom studies were performed using a Jaszczak phantom and a custom made phantom containing small hot lesio...