Electron absorbed fractions and S values in a voxel-based mouse phantom

Mohammadi, A.; Kinase, Sakae   

Electron absorbed fractions (AFs) and S values were evaluated in a voxel-based mouse phantom for preclinical evaluations of radiopharmaceuticals. The sources were considered to be monoenergetic in the electron energy range 10 keV to 4 MeV and distributed uniformly with isotropic emission in the organs. The radiation transport was simulated using the Monte Carlo method. It was confirmed that electron AFs were dependent on the volume, density and geometry of the source and target organs. The electron AFs for organ self-irradiation, i.e., target is source, decreased with increasing electron energy. The electron AFs for organ cross-fire were found to be dependent on electron energy emitted by source and the geometries of source and target. In addition, S values in the major organs of the voxel-based mouse phantom were tabulated for I, Sm, Re and Y using the photon and electron AFs.