Wet harvesting of no-carrier-added ²¹¹At from an irradiated ²⁰⁹Bi target for radiopharmaceutical applications

Astatine-211 is one of the most promising α-emitters for targeted cancer radiotherapy. However, research and clinical trials involving 211At-labeled radiopharmaceuticals have often been impeded due to the irregular and sometimes inconveniently low recovery yields obtained by the currently used dry distillation procedure. Therefore, a wet harvesting procedure isolating 211At from an irradiated 209Bi target was explored. The procedure involves target dissolution in concentrated HNO 3 and extraction of the high oxidation state 211At activity with butyl or isopropyl ether. This method resulted in consistent and nearly quantitative yields. The activity was re-extracted in aqueous phase and applied to NIS6 UVW human glioma cells transfected with cDNA encoding the human sodium/iodide symporter (NIS). The significant and specific uptake of 211At activity by these cells suggests that in the ether phase, high oxidation state 211At is reduced to [ 211At]astatide anion. The synthesis of the first astatinated organic compound derived from wet harvested 211At, 3-astatobenzoic acid (ABA), was achieved.

Duke Scholars

Author Michael Rod Zalutsky Radiology