Diagnostic Performance of ACP3-Targeted PET Imaging in Patients With Primary and Recurrent Prostate Cancer: An Open-Label, Single-Arm, Single-Center Study

This study aims to evaluate the diagnostic performance of \[68Ga\]Ga-OncoACP3 PET imaging, which targets prostate acid phosphatase (ACP3), in men with clinically suspected or confirmed high-risk prostate cancer, or suspected recurrence after treatment. The study will assess the ability of this imaging to detect lesions and its diagnostic performance, including sensitivity, specificity, and accuracy. Histopathology and/or clinical follow-up of at least 6 months will be used as the reference standard. Participants will receive a single intravenous injection of \[68Ga\]Ga-OncoACP3 and undergo a PET/CT scan about 1 hour later. For participants who have already undergone clinically routine PSMA PET imaging, a comparison between the two imaging modalities will be performed. The study will enroll 50 men aged 18 to 90 years. Additionally, the study will explore the correlation between semi-quantitative parameters derived from \[68Ga\]Ga-OncoACP3 PET imaging and pathological markers (ACP3 expression assessed by immunohistochemistry in tumor tissue), and will evaluate the impact of \[68Ga\]Ga-OncoACP3 PET imaging on clinical treatment decisions.

Inclusion Criteria: * Voluntary participation and signed written informed consent before any study-specific procedures; * Male, aged 18 to 90 years; * Clinically suspected high-risk, histologically confirmed, or suspected recurrent prostate cancer after treatment; * Willing and able to comply with scheduled visits, treatment plans, laboratory tests, and other study-related procedures; * Expected survival time greater than 6 months; * Participants' partners agree to use reliable contraceptive measures (such as abstinence, sterilization surgery, oral contraceptives, injectable medroxyprogesterone acetate, or subdermal implants) during the study and for at least 6 months after the last dose of study drug. Exclusion Criteria: * Known or suspected allergy to \[68Ga\]Ga-OncoACP3 injection or any of its excipients; * Any severe unstable disease (e.g., severe cardiac, pulmonary, hepatic, or renal insufficiency) that, in the investigator's judgment, makes the participant unsuitable for the study; * Inability to complete PET/CT examination, including inability to lie flat, claustrophobia, or radiophobia; * Poor compliance or any other condition that, in the investigator's judgment, makes the participant unsuitable for the study; * Prior use of a radiopharmaceutical within less than 10 physical half-lives before study drug administration; * Currently participating in or planning to participate in any drug or device clinical trial during the study period.