The linear response of a radiation dosimeter with absorbed dose rate is a principal requirement in radiotherapy. Fowler's model for electrical conductivity, s of a solid-state detector and absorbed dose rate, Dr is of the form σ ∝ Δ Dr where Δ is the linearity index that can take on a range of values around unity. Utilising synthetic diamond detectors of various types as sensors, this study inv...

Background: Polymer composites when reinforced with heavy metals in the form of micro/nano particles are efficient gamma- and X-ray shielding materials providing such advantageous features as cost-effectiveness, light-weight factor, flexibility, non-toxicity, conformability over conventional shields. Materials and Methods: In this paper the influence of weight percentages and particle sizes of ...

AIMS To evaluate the dosimetric profile among three-dimensional conformal radiotherapy (3D-CRT) and stereotactic radiotherapy (SRT) for the treatment of intracranial tumors. MATERIALS AND METHODS Seventeen patients with intra cranial tumors of benign nature or low malignant potential were enrolled and planned for SRT as well as 3D-CRT. Dosimetric comparison between these two plans was done co...

This study evaluates changes in the dosimetric characteristics of a Varian Millennium 80-leaf multileaf collimator (MLC) in a radiation field. In this study, dose rate, scatter factor, percentage depth dose, surface dose and dose in the buildup region, beam profile, flatness and symmetry, and penumbra width measurements were made for 6-MV and 15-MV photon beams. Analysis of widths between 50% d...

The purpose of this study is to perform dosimetric validation of Monaco treatment planning system version 5.1. The Elekta VersaHD linear accelerator with high dose rate flattening filter-free photon modes and electron energies was used in this study. The dosimetric output of the new Agility head combined with the FFF photon modes warranted this investigation into the dosimetric accuracy prior t...

PURPOSE Radiotherapy of the neck is known to cause carotid artery stenosis. We compared the carotid artery dose received between volumetric modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (IMRT) plans in patients with early glottic cancer. MATERIALS AND METHODS Twenty-one early glottic cancer patients who previously underwent definitive radiotherapy ...

introduction for dose measurement in megavoltage (mv) photon beams with ion chambers, the effect of volume occupied by the air cavity is not negligible. therefore, the result of measurement should be corrected with a displacement perturbation correction factor (pdis) or using an effective point of measurement (epom). the aim of this study is to calculate the epom for cylindrical ion chamber and...

Radiochromic film has become an important tool to verify dose distributions in highly conformal radiation therapy such as IMRT. Recently, a new generation of these films, EBT3, has become available. EBT3 has the same composition and thickness of the sensitive layer of the previous EBT2 films, but its symmetric layer configuration allows the user to eliminate side orientation dependence, which i...

background: identify the optimal technique of radiotherapy for patients with high grade glioma. our initial year of experience with rapidarc radiation therapy. materials and methods: planning ct scans of 50 patients with grade iv glioma were reviewed and three plan sets by 3d conformal radiotherapy (3dcrt), intensity modulated radiotherapy (imrt) and rapid arc (ra) were generated and the plans ...