188Re(Sn)HEDP-A therapeutic radiopharmaceutical : Preparation and biodistribution studies

188 Re(Sn)HEDP is a palliation agent for osseous metastases radiotherapy; the breast, prostate or thyroid cancers generally metastasize to the skeleton with severe bone pain. The aim of this study is a HEDP kit formulation for 188 Re labeling establishing of a fast, reproducible and accurate labeling technique, as well as the in vivo biological testing by biodistribution studies of 188 Re(Sn)HEDP obtained by different labeling techniques. Preclinical (animal) studies are required to determine the biological distribution and the route and extent of excretion of the radiopharmaceutical. The results concerning labeled compound biodistribution show a good specific accumulation of 188 Re(Sn)HEDP in bone, the radiation dose percent to gram of investigated organ ratio is a labeling technique function. The best results were obtained for the labeling in the conditions of an inert reaction atmosphere, acid pH (0.5-1), using carrier added labeling technique and incubation temperature 100°C.