High-Efficiency Cationic Labeling Algorithm of Macroaggregated Albumin with 68Gallium.

PURPOSE: The generator product radionuclide gallium-68(68Ga) is widely used for PET/CT imaging agents and the 68Ga-labeled MAA is an attractive alternative to 99mTc-labeled MAA. Using a commercially available MAA labeling kit for 99mTc, we presented a reliable synthesis protocol with a highly efficient, organic solvent-free cationic method in GMP conditions in the Scintomics automated synthesis unit.
METHODS: The labeling process was performed by incubating for 7 min at 90 °C in the borax vial containing the generator product 68GaCl3 MAA-HEPES eluted from the PSH+ cartridge with 1.5 mL 5 molar NaCl. Quality control of the final product content was examined, and radiopharmaceutical production was carried out in accordance with GMP guidelines.
RESULTS: 68Ga eluted from the generator was obtained in more than 99% radiochemical purity and efficiency. In this case, the labeling efficiency was found to be >99%. When the results of SEM-EDX analysis in the final product were examined, it was determined that most of toxic metals were no appreciable in the product content.
CONCLUSIONS: The radiochemical and chemical purity of the final product allows direct use without purification steps to remove "free 68Ga" or other toxic compounds. © Korean Society of Nuclear Medicine 2021.