Mean skeletal dose factors for beta-particle emitters in human bone. Part I: volume-seeking radionuclides.

Based on calculations by Whitwell and Spiers, mean skeletal dose factors for beta-particle emitters have been derived for application to dosimetry in nuclear medicine, radiobiology and radiation protection. The dose factors apply to bone-seeking radionuclides that are depostited more or less uniformly throughout the human mineralized skeleton and are defined as: (1) vDM/DB, the mean dose to the haemopoietic marrow in trabecular bone as a fraction of the "dose to bone", DB; (2) vDs/DB, the mean dose to endosteal (osteogenic) tissue lying in a zone 0--10 micron from trabecular surfaces, also as a fraction of the dose DB. Dose factors are given for three ages, 1.7, 9 and 44 years and for eight radionuclides, ranging in mean beta-particle energy from 0.05 MeV (14C) to 0.93 MeV (90Y). Dose factors, calculated for a single lumbar vertebra of an infant aged 3.5 weeks, enable approximate values of mean skeletal dose factors to be estimated for ages less than 1.7 years. Limited data are also reported on dose factors for the femoral cortex from subjects aged 9 and 50 years.