Dose distribution for endovascular brachytherapy using Ir-192 sources: comparison of Monte Carlo calculations with radiochromic film measurements

Abstract

An analysis of Ir-192 source distribution using the Monte Carlo method and radiochromic film experiments for endovascular brachytherapy is presented. Three different source possibilities, namely, mHDR Ir-192 sources with 5 mm and 2.5 mm step sizes and Ir-192 seed sources with 1 mm air gap are investigated to obtain uniform radial dose distribution throughout the treatment area. From this study, it is inferred that mHDR Ir-192 sources with 2.5 mm step size are effective for getting dose uniformity. Hence, different restenosis geometries, namely, linear, dumb bell and hairpin, are simulated with 2.5 mm step size, 15 mHDR Ir-192 sources using the Monte Carlo technique and the results are compared experimentally by using radiochromic films. The results from both methods agreed to within 7%. Further, it is also inferred that for the dosimetry of endovascular brachytherapy, the film dosimetry may be considered adequate, even if the film calibration is time consuming and requires adequate dosimetric procedures.

Verification of high dose rate brachytherapy dose distributions with EBT3 Gafchromic film quality control techniques

“…In reviewing experimental dosimetric methods for brachytherapy, Perez-Calatayud et al (2012) commented that while radiochromic film dosimetry is a promising technique, it should be considered 'under development at this time' because of a number of artefacts, including non-uniformity, dose-rate dependence, film darkening kinetics and scanner artefacts. Radiochromic film has been used in brachytherapy dosimetry by many investigators over the last decade to make specific measurements or to verify Monte Carlo generated TG43based source model data (Chiu-Tsao et al 2006, Sureka et al 2007, Bonnet et al 2008, Hanley et al 2008, Kuo et al 2009, Hira et al 2010, Lliso et al 2011, Aldelaijan et al 2011, Uniyal et al 2012. However there have been no publications to date utilizing the latest Gafchromic EBT3 radiochromic film nor advanced film analysis techniques in brachytherapy.…”