Preparation and Dosimetry Evaluation of a Carrier- Free ⁹⁰Y Labeled DOTMP as a Promising Agent for Bone Marrow Ablation

Background and Objective: Skeletal uptake of 90Y-1,4,7,10-tetraazacyclododecane-1,4,7,10- tetramethylene-phosphonate (DOTMP) is used to deliver high doses of this radiopharmaceutical to the bone marrow. Methods: In this research, carrier-free (c.f.) 90Y was obtained from an electrochemical 90Sr/90Y generator. The c.f. 90Y was mixed with 300 μL of DOTMP (20 mg/mL) and incubated under stirring conditions at room temperature for 45 min. Results: The [90Y]Y-DOTMP that was obtained under optimized reaction conditions had high radiochemical purities (>98%). Moreover, the radiolabeled complex exhibited excellent stability at room temperature, as well as in human serum. The biodistribution studies in rats showed the favorable selective skeletal uptake with rapid clearance from the blood, albeit with insignificant accumulation of activity in other non-target organs for the radiolabeled complex. Also, the present work has utilized the Monte Carlo codes MCNP-4C to simulate the depth dose profile for 90Y in a mice femur bone and compared with that produced by 153Sm and 177Lu. Conclusion: The results show that the absorbed dose produced by 90Y in the bone marrow is higher than 153Sm and 177Lu per 1MBq of the injected activity.