Availability of Yttrium-90 from Strontium-90: A Nuclear Medicine Perspective

Yttrium-90 (T-1/2 64.1 hours, E-beta max = 2.28 MeV) is a pure beta(-) particle emitting radionuclide with well-established applications in targeted therapy. There are several advantages of Y-90 as a therapeutic radionuclide. It has a suitable physical half-life (similar to 64 hours) and decays to a stable daughter product Zr-90 by emission of high-energy beta(-) particles. Yttrium has a relatively simple chemistry and its suitability for forming complexes with a variety of chelating agents is well established. The Sr-90/Y-90 generator is an ideal source for the long-term continuous availability of no-carrier-added Y-90 suitable for the preparation of radiopharmaceuticals for radionuclide therapy. The parent radionuclide Sr-90, which is a long-lived fission product, is available in large quantities from spent fuel. Several useful technologies have been developed for the preparation of Sr-90/Y-90 generators. There are several well-established radiopharmaceuticals based on monoclonal antibodies, peptides, and particulates labeled with Y-90, that are in regular use for the treatment of some forms of primary cancers and arthritis. At present, there are no generators for the elution of Y-90 that can be set up in a hospital radiopharmacy. The radionuclide is procured from manufacturers and the radiopharmaceuticals are formulated on site. This article reviews the development of Sr-90/Y-90 generator and the development of Y-90 radiopharmaceuticals.