Report of the ad hoc committee of the AAPM radiation therapy committee on 125I sealed source dosimetry

Purpose: Two developments in I-125-sealed source dosimetry have necessitated swift and accurate implementation of TG-43 dosimetry in clinic: (a) the dosimetry constants of I-125 endorsed by the AAPM Task Group 43 Report result in calculated dose rate that deviates by as much as 15 % from currently accepted dose-rate distributions, and (b) The National Institute of Standards and Technology (NIST) has proposed modifying the I-125 air-kerma strength standard by approximately 10 %. Methods and Materials: The ad hoc committee of AAPM Radiation Therapy Committee describes specific procedures to implement these two developments without causing confusion and mistakes. Conclusions: Confusion and mistakes may be avoided when the following two general steps are taken: 1) STEP L, TG-43 implementation, and 2) STEP II, new air-kerma strength standard implementation when available from NIST. (C) 1998 Elsevier Science Inc.