All of the images were interpreted by a team of two nuclear medicine physicians and one radiologist. In cases of questionable findings, the decision was made by consensus of at least two observers using pre-specified criteria. All of the readers were blinded to the patient's clinical history, blood tests, and previous imaging findings. If patient have consistent findings between Ga68 PSMA ligand PET/CT and other complementary workups, the patients are deemed as true positive or negative. For patients with discrepancy image findings between Ga68 PSMA ligand PET/CT and the other complementary workups, biopsy, needle aspiration or operation will be arranged for histology confirmation. The final results of Ga68-PSMA ligand PET/CT scan will be depend on the histology finding.