MODELING OF INTERNAL DOSE DISTRIBUTIONS DURING SR-89 TREATMENT OF A PATIENT WITH BONE METASTASES

A model of strontium biodistribution similar to the one created by the International Commission on Radiological Protection (ICRP) was applie d for activity and absorbed dose calculations in a patient with bone m etastases treated with Sr-89 strontium chloride. Metastases are repres ented just like all other organs and tissues collecting strontium. Dat a from the ICRP's standard Reference Man were used. Results: Results i nclude calculated time-activity data for all model compartments and fo r relevant target organs. Absorbed doses per unit administered activit y were calculated for blood (0.036 cGy/MBq), soft tissues (0.046 cGy/M Bq), bone marrow (1.15 cGy/MBq), bone surface (1.45 cGy/MBq), upper la rge intestine (ULI) (0.13 cGy/MBq), lower large intestine (LLI) (0.38 cGy/MBq), bladder (0.12 cGy/MBq), and metastases (37.5 cGy/MBq). Concl usions: Results of the absorbed dose calculations are comparable with results presented in references for specific clinical cases. Discrepan cies in dose values may be effected by the size of metastases and the patient's condition.