文摘
86Y is an attractive PET radionuclide due to its intermediate half-life. 86Y was produced via the 86Sr(p,n)86Y nuclear reaction. Enriched SrCO3 or SrO was irradiated with 2-6 μA of beam current for <4 h on a CS-15 cyclotron. It was shown that the SrO target could withstand at least 6 μA of beam current, a significant improvement over a maximum of 2 μA on the SrCO3 target. Average yields of 4.5 mCi/μA·h were achieved with SrO, which represent 71 % of the theoretical yield, compared to 2.3 mCi/μA·h with SrCO3. The radioisotopic contaminants were 86mY (220 % ), 87Y (0.27 % ), 87mY (0.43 % ) and 88Y (0.024 % ). 86Y was isolated in an electrochemical cell consisting of three Pt electrodes. The solution was electrolyzed at 2000 mA (40 min) using two Pt plate electrodes. A second electrolysis (230 mA for 20 min) was performed using one Pt plate and a Pt wire. On average, 97.1 % of the 86Y was recollected on the Pt wire after a second electrolysis. The 86Y was collected from the Pt wire using 2.8 M HNO3/EtOH (3:1). After evaporation, 86Y was reconstituted in 100 μl of 0.1 M HCl. Target materials were recovered as SrCO3 and then converted to SrO by thermal decomposition at 1150°C. Specific activity of 86Y was determined to be 29±19 mCi/μg via titration of 86Y(OAc)3 with DOTA or DTPA. We have established techniques for the routine, economical production of high purity, high specific activity 86Y on a small biomedical cyclotron that are translatable to other institutions.
