@Article{Gimenez-Alventosa_etal2018,
author="Gimenez-Alventosa, V.
and Gimenez, V.
and Ballester, F.
and Vijande, J.
and Andreo, P.",
title="Correction factors for ionization chamber measurements with the {\textquoteright}Valencia{\textquoteright} and {\textquoteright}large field Valencia{\textquoteright} brachytherapy applicators",
journal="Physics in Medicine and Biology",
year="2018",
publisher="Iop Publishing Ltd",
volume="63",
number="12",
pages="125004 - 10pp",
optkeywords="skin applicator; Valencia applicator; large field Valencia applicator; HDR brachytherap; brachytherapy dosimetry; Monte Carlo",
abstract="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 {\textquoteright}Valencia{\textquoteright} and {\textquoteright}large field Valencia{\textquoteright} 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 active volume with a Type A uncertainty of the order of 0.1{\%}. The average energies of the photon spectra arriving at the surface of the water phantom differ by approximately 10{\%}, being 384 keV for the {\textquoteright}Valencia{\textquoteright} and 343 keV for the {\textquoteright}large field Valencia{\textquoteright}. The ionization chamber correction factors have been obtained for both applicators using three methods, their values depending on the applicator being considered. Using a depth-independent global chamber perturbation correction factor and no shift of the effective point of measurement yields depth-dose differences of up to 1{\%} for the {\textquoteright}Valencia{\textquoteright} applicator. Calculations using a depth-dependent global perturbation factor, or a shift of the effective point of measurement combined with a constant partial perturbation factor, result in differences of about 0.1{\%} for both applicators. The results emphasize the relevance of carrying out detailed Monte Carlo studies for each shielded brachytherapy applicator and ionization chamber.",
optnote="WOS:000434682500004",
optnote="exported from refbase (https://references.ific.uv.es/refbase/show.php?record=3609), last updated on Fri, 22 Jun 2018 11:10:35 +0000",
issn="0031-9155",
doi="10.1088/1361-6560/aac27a",
opturl="https://doi.org/10.1088/1361-6560/aac27a",
language="English"
}