BACKGROUND Conventional phantom-based planar dosimetry (2D-PBD) quality assurance (QA) using gamma pass rate (GP (%)) is inadequate to reflect clinically relevant dose error in intensity-modulated radiation therapy (IMRT), owing to a lack of information regarding patient anatomy and volumetric dose distribution. This study aimed to evaluate the dose distribution accuracy of IMRT delivery for na...

conclusions the automatic bolus-tracking method, results in higher contrast enhancement of the aorta and spleen at the portal phase, but has no effect on liver enhancement. however, bolus tracking is associated with reduced variability for liver enhancement among different patients. results forty-eight patients (23 male, 25 female, mean age=56.4±13.5 years) were included. the contrast enhanceme...

The purpose of this study was to compare International Commission on Radiation Units and Measurements (ICRU, report 38) reference points, used in conventional brachytherapy planning, with Computed Tomography (CT)-based volumetric calculations of radiation doses for target volumes and organs at risk in biopsy-proven cervix carcinoma patients. All patients underwent brachytherapy using CT-compati...

We evaluated the changes in the dose distribution of radiation during volumetric arc radiotherapy (VMAT), to determine the right time for adaptive replanning in prostate cancer patients with progressive weight (WT) changes. Five prostate cancer patients treated with VMAT were selected for dosimetric analysis. On the original computed tomography images, nine artificial body contours were created...

Computed tomography (CT) dosimetry normally uses an ionization chamber 100 mm long to estimate the computed tomography dose index (CTDI), however some reports have already indicated that small devices could replace the long ion chamber to improve quality assurance procedures in CT dosimetry. This paper presents a novel dosimetry system based in a commercial phototransistor evaluated for CT dosi...

A pelvimetry examination is sometimes prescribed to a pregnant woman at the end of her pregnancy in order assess dimensions pelvis prior childbirth. This has long been performed by using X-ray, but now increasingly being replaced CT-scan The objective this study radiation doses received during practical CT Hitashi Supria 16-slice scanner. were estimated Monte Carlo (MC)-based simulation with GA...

Background: The Diagnostic reference levels (DRLs) play a critical role in the optimization of radiation dose especially, in some conditions like pediatrics. They are useful indicators by which the radiologists can be aware of delivered excess radiation doses to the patients, and take corrective actions if necessary. In order to meet some requirements for establishing the national computed tomo...

Introduction: The Diagnostic reference levels (DRLs) play a critical role in the optimization of radiation dose especially, in some conditions like pediatrics. They are useful indicators by which the radiologists can be aware of delivered excess radiation doses to the patients, and take corrective actions if necessary. In order to meet some requirements for establishing the nat...

The aims of this study were to investigate the frequency of Portuguese computed tomography (CT) examinations, identify protocol application and establish diagnostic reference levels (DRLs). CT departments (n=211) were surveyed nationally (June 2011-January 2012) and CT protocol information and dose data were collected, as were retrospective age-categorised paediatric CT data from three national...