Open AccessMonte Carlo modeling of60Co HDR brachytherapy source in water and in different solid water phantom materials
Author(s) -
Srinivas Sridhar,
T. Palani Selvam,
RS Vishwakarma,
G. Chourasiya
Publication year - 2010
Publication title -
journal of medical physics/journal of medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.292
H-Index - 24
eISSN - 1998-3913
pISSN - 0971-6203
DOI - 10.4103/0971-6203.58779
Subject(s) - imaging phantom , brachytherapy , polystyrene , monte carlo method , materials science , detector , biomedical engineering , nuclear medicine , physics , optics , composite material , mathematics , radiology , radiation therapy , medicine , polymer , statistics
The reference medium for brachytherapy dose measurements is water. Accuracy of dose measurements of brachytherapy sources is critically dependent on precise measurement of the source-detector distance. A solid phantom can be precisely machined and hence source-detector distances can be accurately determined. In the present study, four different solid phantom materials such as polymethylmethacrylate (PMMA), polystyrene, Solid Water, and RW1 are modeled using the Monte Carlo methods to investigate the influence of phantom material on dose rate distributions of the new model of BEBIG (60)Co brachytherapy source. The calculated dose rate constant is 1.086 +/- 0.06% cGy h(-1) U(-1) for water, PMMA, polystyrene, Solid Water, and RW1. The investigation suggests that the phantom materials RW1 and Solid Water represent water-equivalent up to 20 cm from the source. PMMA and polystyrene are water-equivalent up to 10 cm and 15 cm from the source, respectively, as the differences in the dose data obtained in these phantom materials are not significantly different from the corresponding data obtained in liquid water phantom. At a radial distance of 20 cm from the source, polystyrene overestimates the dose by 3% and PMMA underestimates it by about 8% when compared to the corresponding data obtained in water phantom.