Optimization of synthesis conditions of [68Ga]Ga-PSMA-D5 and its clinical application in prostate cancer

Radioisotope-labeled prostate-specific membrane antigen (PSMA) PET tracers have gained popularity in diagnosing prostate cancer (PCa). Recently, a novel biphenyl-containing tracer [⁶⁸Ga]Ga-PSMA-D5 targeting PSMA has been developed for PET imaging of PCa. The advantages of [⁶⁸Ga]Ga-PSMA-D5 include high tumor uptake, simple synthesis, and convenient labeling, making it a promising PSMA PET tracer. In order to facilitate the routine production and clinical application of [⁶⁸Ga]Ga-PSMA-D5, a straightforward and efficient automated synthesis is described. The optimum labeling parameters were determined at laboratory scale, and subsequently incorporated into an automated production process. Further studies have demonstrated that clinical doses of [⁶⁸Ga]Ga-PSMA-D5 can be prepared within 25 min, with excellent radio chemical purity (>99 %) and activity yield (70.8 % ± 2.3 %, non-decay corrected). All the quality control results satisfy the required criteria for release. PET/CT imaging has shown that [⁶⁸Ga]Ga-PSMA-D5 can safely and effectively target prostate cancer-associated lesions with excellent tumor-to-background contrast. This methodology facilitates efficient synthesis of [⁶⁸Ga]Ga-PSMA-D5 in a commercially available synthesis module and shows diagnostic value for PCa in further clinical application.