Specific absorbed fractions for reference individuals for the current and next general recommendations.

Abstract

The calculation of doses to organs and tissues of interest due to internally emitting radionuclides requires knowledge of, amongst other quantities, the fraction of energy emitted from a source region which is absorbed per mass of a target region. This quantity is the specific absorbed fraction (SAF). Publication 133 contains SAF values for the reference adults, and the Publication 155 contains the same for the reference paediatric individuals along with explanations for their derivation and use. Computation of SAF values involves simulating radiation transport in computational models which represent the geometry of the reference individuals. The reference voxel phantoms of Publications 110 and 143 were used for photon and neutron transport and most of the electron transport. Additional computational models were used for charged particles in small, overlapping, or interlaced geometries. SAF values developed for the next general recommendations will benefit from the development of mesh phantoms including those in Publication 145. Finally, additional opportunities for improvements to SAF values will be discussed.