[Diagnostic performance of 68GA-PSMA PET/CTin patients with prostate cancer]

and aim. Most of the patients with biochemical recurrence after radical prostatectomy undergo salvage radiotherapy without guidance from imaging. In recent years, there has been an increasing role of Gallium-68 prostate specific membrane antigen (68Ga-PSMA) positron emission tomography/computed tomography (PET/CT) imaging in the management of prostate cancer. This study aimed to investigate diagnostic performance of 68Ga-PSMA PET/CT in patients with biochemical recurrence after radical prostatectomy.

From 2016 to 2017, 19 prostate cancer patients were evaluated by 68Ga-PSMA PET/CT at the Urology Clinic of S.P Botkin City Clinical Hospital; 17 of them had a biochemical recurrence and needed restaging of the disease. The age, prostate specific antigen (PSA) values, therapy at the time of the study, and maximum standard uptake value (SUVmax) were evaluated.

The median age of patients was 65 years (interquartile range (IQR) 58.5-70.5), the median total PSA level was 2.36 ng/mL (IQR 1.5-4.19). In 8 of 17 patients, the PSA values did not exceed 2 ng/ml. The median time after radical prostatectomy was 33.2 months. (IQR 12-54.5). Positive PET/CT sites of recurrence were detected in 15 of 17 patients. Nine patients had only one positive site, and in six patients several positive sites were detected. Four patients with PET/CT positive pelvic lymph nodes and/or retroperitoneal space underwent salvage lymphadenectomy. Histological findings confirmed the presence of malignant growth in 3 out of 4 cases.

68Ga-PSMA PET/CT is an effective tool for the early detection of oligometastatic lesions in recurrent prostate cancer.