Gallium 68-PSMA PET/CT for lesion characterization in suspected cases of prostate carcinoma

To assess the feasibility of gallium 68 (Ga)-prostate specific membrane antigen (PSMA) PET/computed tomography (CT) to identify patients who truly harbor clinically significant prostate cancer (PCa) in a cohort of patients with clinical and biochemical/radiological suspicion of PCa.

A total of 118 patients with suspected PCa who underwent Ga-PSMA PET/CT between May 2015 and June 2016 were prospectively included. Final decision on performing biopsy was left to the referring urologist after considering the clinical data, scan findings and discussion with the patient.

Overall, 51 patients were scan negative, among whom six underwent biopsy but was negative for malignancy. In 45 patients, an immediate biopsy could be avoided and put on follow-up. None of these patients were documented to have PCa in the short average follow-up of 6 months. Among 67 patients who were scan positive, 56 patients underwent transrectal ultrasonography-guided biopsy, and malignancy could be documented in 46 of them. In addition, comprehensive initial staging information could be obtained in them, with organ-confined disease demonstrated in 33 patients and metastatic disease in 13 patients.

Ga-PSMA PET/CT can act as a gate keeper in selecting patients with suspected PCa who should undergo an immediate transrectal ultrasonography-guided biopsy and who could be kept on active surveillance.