LU-177-EDTMP - A POTENTIAL THERAPEUTIC BONE AGENT

Lutetium-177 (Lu-177) has both beta particle emissions for a therapeut ic effect and gamma emissions for imaging. This study was undertaken t o synthesize and evaluate Lu-177-EDTMP (ethylenediaminetetramethylene phosphonic acid) as a therapeutic radiopharmaceutical for the palliati on of pain from bone metastases. Chelation of Lu-177 to EDTMP was obta ined by heating for 30 min in boiling water at pH 8.8, resulting in a radiochemical yield of over 99%. The compound was stable for 20 days w ithout any appreciable dissociation. Biodistribution studies in normal rats indicated selective bone accumulation, showing faster blood clea rance, higher bone uptake and higher bone-to-soft tissue ratios than T c-99(m)-MDP. In conclusion, Lu-177-EDTMP has favourable biological and physical characteristics for the palliative treatment of painful bone metastases. ((C) 1998 Lippincott-Raven Publishers).