Preparation and Quality Control of (68)Ga-Citrate for PET Applications

OBJECTIVE(S): In nuclear medicine studies, gallium-68 ((8)Ga) citrate has been recently known as a suitable infection agent in positron emission tomography (PET). In this study, by applying an in-house produced (68)Ge/(68)Ga generator, a simple technique for the synthesis and quality control of (68)Ga-citrate was introduced; followed by preliminary animal studies. METHODS: (68)GaCl(3) eluted from the generator was studied in terms of quality control factors including radiochemical purity (assessed by HPLC and RTLC), chemical purity (assessed by ICP-EOS), radionuclide purity (evaluated by HPGe), and breakthrough. (68)Ga-citrate was prepared from eluted (68)GaCl(3) and sodium citrate under various reaction conditions. Stability of the complex was evaluated in human serum for 2 h at 370C, followed by biodistribution studies in rats for 120 min. RESULTS: (68)Ga-citrate was prepared with acceptable radiochemical purity (>97 ITLC and >98% HPLC), specific activity (4-6 GBq/mM), chemical purity (Sn, Fe<0.3 ppm and Zn<0.2 ppm) within 15 min at 500C. The biodistribution of (68)Ga-citrate was consistent with former reports up to 120 minutes. CONCLUSION: This study demonstrated the possible in-house preparation and quality control of (68)Ga-citrate, using a commercially available (68)Ge/(68)Ga generator for PET imaging throughout the country.