부산대학교 도서관

AbstractRhenium-186g (T1/2= 89.2 h) is a ß-emitter suitable for therapeutic applications. Current production methods rely on reactor production via185Re(n,?) which results in low specific activities, thereby limiting its use. Production by p,dactivation of enriched 186W results in a 186gRe product with a higher specific activity, allowing it to be used for targeted therapy with limited receptors. A test target consisting of pressed, sintered natWO3was proton irradiated at Los Alamos (LANL-IPF) to evaluate product yield and impurities, irradiation parameters and wet chemical Re recovery for proof-of-concept for bulk production of 186gRe. We demonstrated isolation of 186gRe in 97% yield from irradiated natWO3targets within 12 h of end of bombardment (EOB) viaan alkaline dissolution followed by anion exchange. The recovery process has potential for automation, and WO3can be easily recycled for recurrent irradiations. A 186gRe batch yield of 42.7 ± 2.2 µCi/µAh or 439 ± 23 MBq/C was obtained after 24 h in an 18.5 µA proton beam. The target entrance energy was determined to be 15.6 MeV. The specific activity of 186gRe at EOB was measured to be 1.9 kCi (70.3 TBq) mmol-1, which agrees well with the result of a previous 185,186mRe co-production EMPIRE and TALYS modeling study assuming similar conditions. Utilizing enriched 186WO3, we anticipate that a proton beam of 250 µA for 24 h will provide batch yields of 256 mCi (9.5 GBq) of 186gRe at EOB with specific activities even higher than 1.9 kCi (70.3 TBq) mmol-1, suitable for therapy applications.