|
Report No. 021 - Specification of Brachytherapy Source Strength (1987) Category: Reports It is common practice to express source strength of brachytherapy sources in terms of activity or equivalent mass of radium. The output of a brachytherapy source, in terms of exposure rate in free space, can then be obtained by multiplying the source strength by the appropriate exposure-rate constant. In 1974, the National Council of Radiation Protection and Measurements (NCRP) pointed out several shortcomings of these methods, the most important being that they do not specify strength in terms of directly measured quantities. 1 The NCRP recommended that brachytherapy sources should be specified in terms of exposure rate at 1 m in free air with corrections for air attenuation. A similar suggestion was made by Dutreix and Wambersie 2 in 1975. Despite the sound rationale of this proposal there has been little progress towards the use of this specification method in the clinical community. Recent adoption of SI units, and replacement of exposure by air kerma, has reopened this discussion. https://doi.org/10.37206/20 ISBN: 978-0-883185-45-2 Radiation Therapy Committee Task Group #32 Ravinder Nath, Lowell Anderson, Douglas Jones, Clifton Ling, Robert Loevinger, Jeffrey Williamson, William Hanson Committee Responsible: Brachytherapy Subcommittee Last Review Date: |
DISCLAIMER