To prospectively evaluate the radiodrug biodistribution of a novel PET imaging agent [18F]AlF-PSMA-N5 in different organs of prostate cancer patients and its diagnostic efficacy in the diagnosis, recurrence and metastasis of prostate cancer, and to compare with [18F]F-DCFPyL.

[18F]AlF-PSMA-N5 PET/CT was used for initial assessment of prostate cancer or detection of recurrence. The maximum standardized uptake value (SUVmax) was used to evaluate tumor uptake. The sensitivity, specificity, the number and accuracy of lesions identified and the distribution of lesions in each organ were calculated and compared with those of [18F]F-DCFPyL PET/CT.

Inclusion Criteria:

• Aged from 18 to 90 years old;
• Complete MRI images and clinical data (such as PSA level, Gleason grade, etc.);
• Prostate cancer detected by PSA or imaging examination, or clinically suspected recurrence after standardized treatment;
• simultaneous [18F]AlF-PSMA-N5 and [18F]F-DCFPyL examinations within two weeks;
• Willing to undergo surgery or needle biopsy for pathological examination after examination, or confirmed as prostate cancer by histopathology before or after treatment;
• Sign informed consent.

Exclusion Criteria:

• Patients who cannot cooperate with the examination;
• Concurrent malignant tumors;
• Previous alcohol allergy;
• Patients with liver and kidney dysfunction;
• Other circumstances deemed by the investigator to be inappropriate for trial participation.