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

Beta emitting radionuclides have demonstrated excellent properties for radi onuclide endotherapy using appropriate carrier molecules. In an effort to s earch for alternative radionuclides, the preparation of Lu-177-EDTMP was un dertaken, as a palliative agent for bone metastasis. Natural Lu2O3 was irra diated 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 alter native therapeutic radiopharmaceutical, with comparable characteristics as its Sm-153-EDTMP counterpart, was successfully achieved.