Development of methodology for the preparation of 90Sr-90Y generators

Yttrium-90 is a radioisotope of interest in the Nuclear Medicine field. It is considered one of the most useful and important radionuclides for radioimmunotherapeutic applications, and it is promising for certain applications in cancer therapy. Another important application of 90Y is radiosynoviorthesis. This radionuclide has a half-life of 64 h, long-range beta emissions (maximum energy 2.3 MeV) and it decays to a stable daughter with no undesirable intermediate nuclides. Yttrium-90 can be obtained conveniently and inexpensively, in a carrier free form, as a radionuclide generator product by decay of its 28-yr parent, Strontium-90 (90Sr). 90Sr is a fission product present in large quantities in high level waste generated from the reprocessing of spent nuclear fuel but it requires its processing for recovery followed by purification to very high levels of radionuclidic and chemical purity that can be used as raw material for generator feed. The 90Sr-90Y generators could be used for several months to several years due to the long half-life of 90Sr. Several methods for the separation of 90Y from 90Sr utilizing solvent extraction and ion exchange have been reported in the literature. Because of simplicity, the ion exchange methods are most commonly used in this generator systems. The objective of this work is to develop a methodology for the preparation of 90Sr-90Y generators using a cation exchange resin method. 90Sr is strongly adsorbed in the resin and 90Y is eluted in 0.003 M EDTA. The preliminary results will be shown together with the radionuclidic quality control results. (author)