68Ga-PSMA-CYC is a novel radiotracer targeting PSMA. In this study, we investigated the safety, biodistribution, radiation dosimetry of 68Ga-PSMA-CYC PET/CT in patients with prostate cancer, and performed a head-to-head comparison with 68Ga-PSMA-617 and 68Ga-PSMA-11 to evaluate its diagnostic performance.

Prostate cancer (PCa) is one of the most common malignant tumors among men worldwide. Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein that is highly expressed in PCa and its metastatic lesions, making it an ideal target for the precise diagnosis and treatment of PCa. Various low-molecular-weight radiopharmaceuticals targeting PSMA have been developed, such as PSMA-11 and PSMA-617, which can be labeled with 68Ga or 177Lu. 68Ga-PSMA-CYC is a novel radiotracer that has demonstrated favorable in vivo and in vitro stability in preliminary studies, with specific accumulation in PCa, high binding affinity, and good safety profile, making it a promising candidate for further investigation. This prospective study aims to investigate the safety, biodistribution, radiation dosimetry of 68Ga-PSMA-CYC PET/CT in patients with prostate cancer, and performed a head-to-head comparison with 68Ga-PSMA-617 and 68Ga-PSMA-11 to evaluate its diagnostic performance.

Inclusion Criteria:

• confirmed treated or untreated prostate cancer patients;
• signed written consent.

Exclusion Criteria:

• known allergy against PSMA;
• any medical condition that in the opinion of the investigator may significantly interfere with study compliance.