Objective: Our study aimed to investigate the efficacy of Gallium-68 (68Ga) prostate-specific membrane antigen (PSMA) positron emission tomography-computed tomography (PET-CT) in terms of focus detection in the presence of biochemical recurrence (BCR) after primary curative treatment in patients with prostate cancer (PCa).

Methods: This study included 34 PCa patients who underwent 68Ga-PSMA PET-CT for BCR following radical prostatectomy (RP) or primary curative radiotherapy (RT), between August 2017-December 2018 at Okmeydanı Training and Research Hospital, Clinic of Nuclear Medicine.

Results: Thirteen patients (38.2%) had RP and 21 (61.8%) had RT. PSMA-positive lesion was detected in 21 (61.7%) of 34 patients. PSMA positive lesion was present in six of 13 patients (46.1%) in the RP group and 15 of the 21 patients (71.4%) in the RT group. There was a PSMA-positive lesion in five out of 13 patients with serum prostate-specific antigen (PSA) values of 0.01-1 ng/mL, in five of eight patients with serum PSA values of 1-2 ng/mL, in four of five patients with serum PSA values of 2-5 ng/mL, and in seven of eight patients with serum PSA values of >5 ng/mL. PSA levels of PSMA-positive patients were found to be significantly higher than those of PSMA-negative, whereas PSA-positive and negative patients did not differ significantly in terms of PSA doubling time, time to BCR, and Gleason score.

Conclusion: 68Ga-PSMA PET-CT is an effective method in the diagnosis of BCR after primary curative treatment in PCa patients.