Abstract
Thehuman internal dosimetry of the radionuclidic impurities of samarium-153 in a new bone-seeking radiopharmaceutical, (153)Sm-1,4,7,10tetraazacyclododecanetetramethylenephosponic acid ((153)Sm-DOTMP), has been estimated from preclinical data. The effective dose from the impurities in lower-specific-activity (153)Sm is less than 17% of the effective dose from pure Sm-153. It has a background-equivalent radiation time for a dosage of 37 MBq/kg of less than one-half year.