Lutetium-177-EDTMP for bone pain palliation. Preparation, biodistribution and pre-clinical studies

Beta emitting radionuclides have demonstrated excellent properties for radionuclide endotherapy using appropriate carrier molecules. In an effort to search for alternative radionuclides, the preparation of 177 Lu-EDTMP was undertaken, as a palliative agent for bone metastasis. Natural Lu 2 O 3 was irradiated at the RA-3 Nuclear Reactor of the Ezeiza Atomic Center (Argentina). The optimum molar ratio of Lu:EDTMP, the radiochemical purity, the in vivo and in vitro stability and the biological behaviour in Wistar rats and New Zealand rabbits were studied. The results indicate that an excellent alternative therapeutic radiopharmaceutical, with comparable characteristics as its 153 Sm-EDTMP counterpart, was successfully achieved.