Radioiodine: biokinetics, mean dose and dose distribution.

For the radioiodine isotopes I-123, I-125, I-131, and I-132 the mean tissue dose and local dose distribution in the epithelial cells of a follicle have been calculated and compared to each other. Moreover, dose factors have been estimated for I-131 as a function of age considering age-dependent ingestion (milk consumption) and inhalation rates. Thereby, besides age-dependent biological half-times and thyroid masses, the thyroidal iodine uptake was assumed to be independent from age and taken to be about 1.7 the normal for an insufficient dietary iodine intake as in the Federal Republic of Germany.