Manual production and quality control of 68Ga-PSMA-11 radiopharmaceutical for PET-CT imaging of prostate cancer: optimization and 60 production series experience

Background: 68Ga-PSMA-11, a novel PET radiopharmaceutical, is currently used for imaging of almost all prostate cancers. However, automatic radiolabeling procedures have been recommended. In this research, according to the chemical nature of the PSMA-11, manual, optimized and safe production of this radiopharmaceutical has been investigated and a standard method has been presented to achieve a repeatable quality with the use of an Iran made 68Ge/68Ga generator. Methods: The effect of the PSMA-11 weight, temperature, pH, and radiolabeling time on the radiochemical purity (RCP) was evaluated. The effectiveness of the optimized condition on the quality of radiopharmaceutical in 60 production series was studied according to US Pharmacopeia guidelines. Also, by monitoring the dose rate of the personnel, the safety of the manual production was checked. Results: Increasing the temperature from room temperature (RT) to 40◦C enhanced the RCP of 10 μg of PSMA-11 to acceptable ranges of > 90%. The weights of 25 and 50 μg had RCPs>90% at RT. The appropriate pH range was determined to be 5-6. The 10 minutes’ reaction time yielded a repeatable RCP>90% for the 10 μg PSMA-11 in 60 production series. Body and hands dose rates were 15% and 2.4% of the recommended annual dose rate limit for body and hands, respectively. Conclusion: The results indicate the high quality of the Iran made 68Ge/68Ga generator. PET-CT centers can in-site, manually, safely and with repeatable quality produce 68Ga-PSMA-11 for prostate cancer imaging away from the challenge of transport problems.