Incidentally Detected 18F-FDG-Avid Prostate Cancer Diagnosed Using a Novel Fusion Biopsy Platform

Abstract

Background: Localized prostate cancer rarely undergoes a shift in metabolism towards aerobic glycolysis, a process known as the Warburg Effect. Because of this, positron emission tomography (PET)/CT imaging using 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) is uncommonly used to evaluate patients with early-stage prostate cancer. However, men undergoing an 18F-FDG PET/CT for unrelated reasons will on occasion be found to have radiotracer uptake within the prostate gland. The appropriate work-up of these patients is poorly defined. Case Presentation: We present the case of a 61-year-old man with a history of tonsillar squamous cell carcinoma who was incidentally found on 18F-FDG PET/CT to have a hypermetabolic nodule within the prostate. The patient's prostate-specific antigen level was 2.1 ng/cc and digital rectal examination revealed no abnormalities. The patient underwent a targeted prostate biopsy of the lesion using the KOELIS Trinity biopsy platform, which uniquely allows for the real-time overlay of transrectal ultrasonography and PET/CT images. Targeted biopsy revealed Gleason score 4 + 3 = 7 (grade group 3) prostate cancer. Conclusion: Although the incidental detection of 18F-FDG uptake within the prostate is uncommon, more than half of all patients will be found to have prostate cancer. Based on this case and our review of the available medical literature, it is our belief that men with incidentally detected uptake of 18F-FDG within the prostate should undergo further evaluation with a prostate biopsy. This recommendation is supported by data suggesting that 18F-FDG-avid prostate cancer represents a more aggressive clinical phenotype.