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.