Search results for "Radiation Dosimeters"
showing 5 items of 5 documents
Influence of the simultaneous calibration of multiple ring dosimeters on the individual absorbed dose
2021
Abstract Ring dosimeters for personal dosimetry are calibrated in accredited laboratories following ISO 4037-3 guidelines. The simultaneous irradiation of multiple dosimeters would save time, but has to be carefully studied, since the scattering conditions could change and influence the absorbed dose in nearby dosimeters. Monte Carlo simulations using PENELOPE-2014 were performed to explore the need to increase the uncertainty of H p 0 .07 in the simultaneous irradiation of three and five DXT-RAD 707H-2 (Thermo Scientific) ring dosimeters with beam qualities: N-30, N-80 and N-300. Results show that the absorbed dose in each dosimeter is compatible with each of the others and with the refere…
Calibration of a thermoluminescent dosimeter worn over lead aprons in fluoroscopy guided procedures
2018
Fluoroscopy guided interventional procedures provide remarkable benefits to patients. However, medical staff working near the scattered radiation field may be exposed to high cumulative equivalent doses, thus requiring shielding devices such as lead aprons and thyroid collars. In this situation, it remains an acceptable practice to derive equivalent doses to the eye lenses or other unprotected soft tissues with a dosimeter placed above these protective devices. Nevertheless, the radiation backscattered by the lead shield differs from that generated during dosimeter calibration with a water phantom. In this study, a passive personal thermoluminescent dosimeter (TLD) was modelled by means of …
Characterisation of two new radiochromic gel dosimeters TruView™ and ClearView™ in combination with the vista™ optical CT scanner: A feasibility study
2018
This study aims at characterising the properties of TruView™ and ClearView™ two new gel dosimeters (Modus Medical Devices Inc.) and at studying the feasibility of relative dosimetry using these dosimeters and the Vista™ Optical CT scanner to accurately evaluate dose.In this work, we investigated key dosimetric aspects (dose response, energy and dose rate dependence) and stability of these radiochromic gels initiated in preliminary works (Huet et al., 2017; Colnot et al., 2017) using spectrophotometric measurements. Moreover, by mean of optical CT scanning (Vista™), their performances to measure relative depth dose (PDD) and cross profiles were analysed.TruView™ and ClearView™ present a line…
Correction factors for ionization chamber measurements with the ‘Valencia’ and ‘large field Valencia’ brachytherapy applicators
2018
Treatment of small skin lesions using HDR brachytherapy applicators is a widely used technique. The shielded applicators currently available in clinical practice are based on a tungsten-alloy cup that collimates the source-emitted radiation into a small region, hence protecting nearby tissues. The goal of this manuscript is to evaluate the correction factors required for dose measurements with a plane-parallel ionization chamber typically used in clinical brachytherapy for the 'Valencia' and 'large field Valencia' shielded applicators. Monte Carlo simulations have been performed using the PENELOPE-2014 system to determine the absorbed dose deposited in a water phantom and in the chamber act…
Implementation of dosimetry equipment and phantoms at the MedAustron light ion beam therapy facility
2017
Purpose: To describe the implementation of dosimetry equipment and phantoms into clinical practice of light ion beam therapy facilities. This work covers standard dosimetry equipment such as computerized water scanners, films, 2D-array, thimble and plane parallel ionization chambers, but also dosimetry equipment specifically devoted to the pencil beam scanning delivery technique such as water columns, scintillating screens or multi-layer ionization chambers. Method: Advanced acceptance testing procedures developed at MedAustron and complementary to the standard acceptance procedures proposed by the manufacturer are presented. Detailed commissioning plans have been implemented for each piece…