Dose Equivalents in Anthropomorphic Phantoms and their Relation to the Ambient Dose Equivalent H*(10) for External Exposure

Abstract The ICRP has recommended a system of dose limitation based on the dose equivalents in various organs and on the effective dose equivalent HE. Because HE is unmeasurable, it was agreed to estimate HE on the basis of dose equivalents in the ICRU sphere. In the past it has already been shown that for external photon radiation the ambient dose equivalent, H*(10), is conservative for HE of the mathematical anthropomorphic phantoms ADAM and EVA. As the dose equivalents of children became more and more important, new anthropomorphic phantoms, based on whole body CT data for a baby and a 7-year-old child were recently developed at GSF. A CT voxel phantom of an Alderson Rando phantom was constructed also. The effective dose equivalents and some organ dose equivalents of these three voxel phantoms are related to the ambient dose equivalent, H*(10), for different photon energies and various geometries.