¹⁸F-Fluciclovine versus PSMA PET Imaging in Primary Tumor Detection during Initial Staging of High-Risk Prostate Cancer: A Systematic Review and Meta-Analysis

Abstract

P rostate cancer is the most common noncutaneous cancer and second leading cause of cancer death in men in the United States (1). About 15% of patients with prostate cancer present with high-risk disease, which has a high propensity for local or systemic recurrence despite optimal treatment (2). High-risk prostate cancer is defined as a "clinical T category greater than or equal to T3, Gleason score … greater than or equal to 8, or serum prostatespecific antigen … greater than 20 ng/mL prior to definitive therapy," adapted from criteria proposed by D'Amico et al (3,4). The identification and timely stratification of these patients with accurate workup is crucial for appropriate management, which may further improve survival (5). The staging system developed by the American Joint Committee on Cancer acknowledges the use of imaging for preoperative local T staging of prostate cancer and MRI as the current standard (5,6). However, as the need to accurately identify these high-risk patients has shifted the focus to functional imaging, PET has shown superior accuracy, especially in suspicious cases (6). 18 F-fluciclovine is a synthetic amino acid radiotracer that enters the cell via the human l-type amino acid transporters, which are upregulated in certain malignancies like prostate cancer, particularly in aggressive disease (7,8). 18 Ffluciclovine (Axumin; Blue Earth Diagnostics) (9) has been approved by the U.S. Food and Drug Administration for localization of biochemical recurrence of prostate cancer after definitive therapy but not for initial staging. Turkbey et al showed that combining the information from 18 Ffluciclovine PET with multiparametric MRI (mpMRI) increased the positive predictive value for detecting prostate cancer from 76% for mpMRI alone to 82% (10). While 18 F-fluciclovine PET/MRI has definite value in the initial staging of primary prostate cancer, it also demonstrated potential to predict aggressiveness of prostate cancer (11)(12)(13).Another group of PET tracers uses prostatespecific membrane antigen (PSMA), a transmembrane type II glycoprotein expressed by prostate cancer cells. Gallium 68 ( 68 Ga)-labeled PSMA tracers (PSMA N,Nʹ-bis-[2-hydroxy-5-(carboxyethyl) benzyl]This copy is for personal use only. To order printed copies, contact