Preparation and Biodistribution of ¹¹⁷Sn^m （¹⁸⁸Re, ¹⁵³Sm）-EDTMP in Mice

In this work, EDTMP is synthesized and radiolabeled with ¹¹⁷Sn^m, ¹⁵³Sm, and ¹⁸⁸Re separately. The preparation conditions, stability in vitro and lipophilicity of ¹¹⁷Sn^m (¹⁸⁸Re, ¹⁵³Sm)-EDTMP were investigated. Biodistribution of ¹¹⁷Sn^m (¹⁸⁸Re, ¹⁵³Sm)-EDTMP in mice were studied. It is found that ¹¹⁷Sn^m (¹⁸⁸Re, ¹⁵³Sm)-EDTMP are hydrophilic and stable at room temperature and 37℃ in open air. Three kinds of compounds show high bone uptake and bone-to-blood ratio in mice. but ¹⁸⁸Re-EDTMP is not stable enough in vivo. ¹¹⁷Sn^m-EDTMP showes good biological properties, similar to those of ¹⁵³Sm-EDTMP, including higher uptake in skeleton, lower residue in soft tissues and rapid blood clearance. The result shows that ¹¹⁷Sn^m-EDTMP is a potential reagent for skeletal scintigraphy and radiotherapy of bone tumors.