Initial Institutional Experience with 18F-Fluciclovine PET-CT in Biochemical Recurrence of Prostate Cancer.

OBJECTIVES 18F-fluciclovine (fluciclovine) is an amino acid analog approved by the Food and Drug Administration for use as a radiotracer in positron emission tomography (PET) in men with biochemical recurrence of suspected prostate cancer. The purpose of this study was to investigate the initial institutional experience with 18F-fluciclovine in the evaluation of prostate cancer with biochemical recurrence. METHODS This study was a retrospective review of 135 patients who underwent 18F-fluciclovine PET-computed tomography (PET-CT) at a single institution from August 2018 through January 2020. Prognostic information, including prostate-specific level antigen (PSA) at the time of diagnosis, initial risk, initial Gleason score, and initial stage, was reviewed as well as the PSA level at the time of the scan. The images were reviewed by two radiologists with fellowship training in nuclear medicine and additional training to interpret the fluciclovine studies. A minority of studies were reviewed by a third fellowship-trained radiologist under the guidance of the two nuclear medicine-trained radiologists. In cases with abnormal radiopharmaceutical uptake in lymph nodes, the short-axis dimension of the lymph node or largest lymph node with abnormal uptake was noted. If CT or bone scan was performed within 4 months of the 18F-fluciclovine PET-CT, findings on the alternate imaging were compared with the results of the 18F-fluciclovine PET-CT. RESULTS Our institutional positivity rate was 75.6%, with 64 (67.4%) patients with metastatic disease and 71 (52.6%) patients with local recurrence detected by fluciclovine. As expected, the rate of positive examinations increased with increasing PSA values measured at the time of imaging (P < 0.001). Of the 54 patients with nodal disease, 35 had nonpathologically enlarged lymph nodes measuring <1 cm in maximum short-axis dimension. In more than half of the patients in this study, with conventional imaging, fluciclovine either discovered otherwise undetectable metastatic disease or suggested the presence of local recurrence. CONCLUSIONS Our single-institution experience with 18F-fluciclovine PET-CT has the largest number of patients to date in the literature and demonstrates the ability of fluciclovine to help guide clinical management in the detection of early recurrent disease.