A simple and automated method for 161Tb purification and ICP-MS analysis of 161Tb

¹⁶¹Tb is a radiolanthanide with the potential to replace ¹⁷⁷Lu in targeted radionuclide therapy. ¹⁶¹Tb is produced via the neutron irradiation of [160Gd]Gd2O3 targets, and must be purified from ¹⁶⁰Gd and the decay product ¹⁶¹Dy prior to use. Established purification methods require complex conditions or high-pressure ion chromatography (HPIC) which are inconvenient to introduce in a broad user community. In this study, ¹⁶¹Tb was successfully purified by a semi-automated TRASIS system using a combination of TrisKem extraction resins. The resulting product performed well in radiolabelling and in vivo experiments. An ICP-MS method to analyze the radioactive product was developed. Combined with gamma spectroscopy, this method allows the purity of ¹⁶¹Tb being assessed before the decay of the product, providing a useful tool for quality control.