Radial dose distribution from 192Ir seeds at distances far from the source.
Most current tissue attenuation and scattering factors for 192Ir are valid only to distances of 15 cm or less. Monte Carlo calculations using the EGS4 computer code were used to calculate tissue attenuation and scattering factors for 192Ir seed sources with both stainless steel encapsulation and with Pt encapsulation out to a distance of 32 cm from the sources. The data clearly show that polynomial tissue attenuation and scattering factors cannot be extrapolated beyond their range. Encapsulation specific factors are presented here that are valid at large distances from the source.
Thomason
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Loyola-Hines Department of Radiation Therapy, Loyola University Medical Center, Maywood, Illinois 60153.
D001918:Brachytherapy / Q000379:methods*; D003198:Computer Simulation; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D009010:Monte Carlo Method; D011879:Radiotherapy Dosage; D012984:Software
D007496:Iridium Radioisotopes