REPORT OF THE AD HOC COMMITTEE OF THE AAPM RADIATION-THERAPY COMMITTEE ON I-125 SEALED SOURCE DOSIMETRY

Purpose: Two developments in I-125-sealed source dosimetry have necess itated 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 1 5 % from currently accepted dose-rate distributions, and (b) The Natio nal Institute of Standards and Technology (NIST) has proposed modifyin g the I-125 air-kerma strength standard by approximately 10 %. Methods and Materials: The ad hoc committee of AAPM Radiation Therapy Committ ee describes specific procedures to implement these two developments w ithout causing confusion and mistakes. Conclusions: Confusion and mist akes 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 Sc ience Inc.