Terbium-161 (161Tb) is emerging as a promising radionuclide for cancer therapy due to its favorable nuclear properties that are similar to clinically established lutetium-177 (177Lu) along with its therapeutic edge arising from the higher number of Auger and conversion electrons per decay. These low energy electrons result in higher cytotoxicity within a short range of the decaying nuclei to enhance therapeutic efficacy. Despite these promising characteristics, a significant challenge remains in the lack of a domestic 161Tb supply in the United States, which poses an obstacle to the advancement of 161Tb-based radiopharmaceutical research and development. This study developed a reliable cation-exchange high-performance liquid chromatography-based method for purification of reactor-produced 161Tb at quantities suitable to support research and preclinical studies. The purified 161Tb product showed high radionuclidic purity with excellent radiochemical purity, and the successful labeling studies with the DOTA chelator and DOTA-TATE peptide demonstrated the effective incorporation of the purified 161Tb into radiopharmaceuticals designed for targeted cancer therapy.
