Comparison of three different methods in [68 Ga]Ga-PSMA11 radiolabeling.

In this study, quality control parameters such as radiochemical yield, radiochemical purity, and in vitro stability of gallium (⁶⁸ Ga)-prostate-specific membrane antigen-11 ([⁶⁸ Ga]Ga-PSMA11) radiopharmaceutical obtained in a research laboratory with three different synthesis algorithms were evaluated and compared. Gallium (⁶⁸ Ga) chloride precursor to be used in labeling in all three methods was obtained by using ITG brand ⁶⁸ Ge/⁶⁸ Ga generator. The first method for the [⁶⁸ Ga]Ga-PSMA11 radiopharmaceutical was performed with the automated synthesis module, which is widely used in clinical practice. Its radiochemical yield, quality assurance, and stability met expectations. Radiolabeling success, suitability of quality control parameters, and in vitro stability of [⁶⁸ Ga]Ga-PSMA11 radiopharmaceutical performed with ANMI kit were examined. The final product showed success in ⁶⁸ Ga-complexation kinetics. All quality control criteria performed met the expectation for clinical applications. Direct cold labeling of PSMA11 ligand with sodium bicarbonate buffer was examined. Results were similar to the ANMI kit. Considering that all three methods are successful in radiochemical labeling, labeling with NaHCO₃ buffer shows the labeling preference when we choose the cheap, practical, and easy labeling option.