Nuclear medicine program progress report for quarter ending March 31, 1991

In this report the first fabrication and evaluation of an activated carbon-based osmium-194/iridium-194 generator system is described. Iridium-194 (t{sub {1/2}} = 19.2 h) decays by {Beta}{sup {minus}} emission (E{sub max} = 2.24 MeV) and is a potential candidate for radioimmunotherapy. An important characteristic is availability of {sup 194}Ir from decay of reactor-produced {sup 194}Os (t{sub {1/2}} = 6 y). A novel gas thermochromatographic method was developed for the one step conversion of metallic Os to OsO{sub 4} and subsequent separation and purification of OsO{sub 4}, which was then converted to the K{sub 2}OsCl{sub 6} for generator loading. The yield and the elution profile of carrier-free {sup 194}Ir, and {sup 194}Os breakthrough were determined for a prototype generator which was evaluated over a 10 month-period.l During this period several agents were also supplied to Medical Cooperative investigators, including iodine-123-labelled and iodine-125-labelled fatty acid analogues for studies at the Brookhaven National Laboratory. In addition, gold-198 and tungsten-188/-rhenium-188 generators were shipped to various investigators for therapeutic studies involving tumor-specific antibodies. 19 refs., 3 figs.