Enhancing capacity and synthesis of [68Ga]68-Ga-PSMA-HBED-CC with the lyophilized ready-to-use kit for nuclear pharmacy applications.

Introduction: The authors describe the newly proposed synthesis technique for the gallium-68 (Ga-68)-labeled tracer ([Ga]Ga-PSMA-HBED-CC) for imaging expression of the prostate-specific membrane antigen (PSMA). An effort was applied to design the lyophilized cold kit (isoPROtrace-11) as a time-saving technique resulting in increased radiochemical yields.

Procedures: The initial material for labeling was obtained from a Ge/Ga-generator. For labeling with the lyophilized cold kit isoPROtrace-11, 2.5 ml 0.1 M HCl of the middle Ga-68 elution fraction were added to the kit, shook for dissolving the vial's contents and kept for 5 minutes at room temperature. A systematic comparison was carried out between results obtained with the cold kit technique and with previously used Modular-Lab module concerning the radiochemical yield, purity, and the time of producing.

Results: Automated module-involved synthesis of [Ga]Ga-PSMA-HBED- CC resulted in a radiochemical yield of 84.2 ± 6.3% and purity of >95% after 25 minutes. The room temperature cold kit gave a radiochemical yield of >98% and purity of >95% after 5 minutes.

Conclusion: Using the kit method reduced the labeling time. The cold kit method increased production efficiency because less of the eluted Ga-68 was wasted.