Evaluation of ¹⁸⁸Re- IBA as a novel radiopharmaceutical for bone marrow ablation

In this study, Ibandronate as a third generation of bisphosphonates was labeled with rhenium-188 radionuclide. Production and quality control of ¹⁸⁸Re-IBA radiopharmaceutical was investigated. The radiation absorbed dose of this radiopharmaceutical was evaluated for adult male based on biodistribution data in mice using the RADAR and Sparks and Aydogan methodologies. The ¹⁸⁸Re-IBA was produced with more than 96% radiochemical purity. The highest value of %ID/g was related to bone with 7.11% at 12 h post-injection. About 48% of injected activity was cumulated on the surface of bone tissue 48 h post-injection. The imaging studies confirmed the biodistribution pattern. Radiation absorbed doses of red bone marrow and osteogenic cells were estimated to about 0.39 and 0.71 mGy MBq^-1, respectively. The maximum administrated activity was obtained 73.1 MBq kg^-1 (2.0 mCi kg^-1) of body weight. Effective dose was evaluated about 0.09 mSv MBq^-1. The results were compared with other clinically used bone pain palliation radiopharmaceuticals. It was concluded that the ¹⁸⁸Re-IBA radiopharmaceutical has a great tendency to be absorbed in bone tissue and it can provide sufficient care for bone marrow ablation with low undesired dose to other normal organs.