TY - JOUR
TI - On the use of a novel Ferrous Xylenol-orange gelatin dosimeter for HDR brachytherapy commissioning and quality assurance testing
AU - Pappas, E.P.
AU - Peppa, V.
AU - Hourdakis, C.J.
AU - Karaiskos, P.
AU - Papagiannis, P.
JO - PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
PY - 2018
VL - 45
TODO - null
SP - 162-169
PB - Associazione Italiana di Fisica Medica
SN - null
TODO - 10.1016/j.ejmp.2017.12.015
TODO - polyethylene;  gelatin;  iridium;  phenol derivative;  sulfoxide;  xylenol orange, algorithm;  Article;  brachytherapy;  calibration;  computer assisted tomography;  controlled study;  dose response;  dosimetry;  ferrous xylenol orange gel dosimeter;  flap surface applicator;  gel;  irradiation;  model based dose calculation algorithm;  Monte Carlo method;  optical computed tomography;  radiation dose distribution;  TG 43 based algorithm;  brachytherapy;  computer simulation;  devices;  dosimeter;  electron;  health care quality;  human;  optical tomography;  procedures;  radiation response;  radiometry;  uncertainty, Algorithms;  Brachytherapy;  Calibration;  Computer Simulation;  Dose-Response Relationship, Radiation;  Electrons;  Gelatin;  Humans;  Iridium Radioisotopes;  Monte Carlo Method;  Phenols;  Polyethylene;  Quality Assurance, Health Care;  Radiation Dosimeters;  Radiometry;  Sulfoxides;  Tomography, Optical;  Uncertainty
TODO - Purpose: To evaluate a commercially available Ferrous-Xylenol Orange-Gel (FXG) dosimeter (TrueView™) coupled with Optical-Computed Tomography (OCT) read out, for 3D dose verification in an Ir-192 superficial brachytherapy application. Methods: Two identical polyethylene containers filled with gel from the same batch were used. One was irradiated with an 18 MeV electron field to examine the dose-response linearity and obtain a calibration curve. A flap surface applicator was attached to the other to simulate treatment of a skin lesion. The dose distribution in the experimental set up was calculated with the TG-43 and the model based dose calculation (MBCA) algorithms of a commercial treatment planning system (TPS), as well as Monte Carlo (MC) simulation using the MCNP code. Measured and calculated dose distributions were spatially registered and compared. Results: Apart from a region close to the container's neck, where gel measurements exhibited an over-response relative to MC calculations (probably due to stray light perturbation), an excellent agreement was observed between measurements and simulations. More than 97% of points within the 10% isodose line (80 cGy) met the gamma index criteria established from uncertainty analysis (5%/2 mm). The corresponding passing rates for the comparison of experiment to calculations using the TG-43 and MBDCA options of the TPS were 57% and 92%, respectively. Conclusion: TrueView™ is suitable for the quality assurance of demanding radiotherapy applications. Experimental results of this work confirm the advantage of the studied MBDCA over TG-43, expected from the improved account of scatter radiation in the treatment geometry. © 2017 Associazione Italiana di Fisica Medica
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