Dose rate distribution around 60Co, 137Cs, 198Au, 192Ir, 241Am, 125I (models 6702 and 6711) brachytherapy sources and the nuclide 99Tcm

Abstract

Simple analytical functions derived from point source Monte Carlo calculations on the combined attenuation and scatter factor, B exp(- mu r), for 60Co, 137Cs, 198Au, 192Ir, 241Am, 125I (models 6702 and 6711) brachytherapy sources and the nuclide 99Tcm, for water spherical geometries of radii R=15 and 20 cm are presented. Results for the broadly used 60Co, 137Cs, 198Au and 192Ir brachytherapy sources can be compared directly and found in excellent agreement with the widely accepted data of Meisberger et al in the limited distance range for which the latter are valid. The present authors' data, however, can be used with high accuracy outside this distance range. Dose rate distributions are proposed in accordance with the recommendations for calibration of the brachytherapy sources in terms of reference air kerma rate and were found to be in good agreement with data available in the literature.