Association between PD-L1 expression and 18F-FDG uptake in ovarian cancer

Objective Immunotherapy for programmed cell death 1 (PD-1) and its ligand, PD-L1, has been considered an effective treatment for ovarian cancer. F-18-labeled fluoro-2-deoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) is a widely used noninvasive imaging tool for diagnosing several cancers. In this study, we investigated the association between PD-L1 expression and the maximum standardized uptake value (SUVmax) using F-18-FDG PET/CT. Methods We retrospectively analyzed clinical data of patients with ovarian cancer who underwent F-18-FDG PET/CT. Patients were categorized into two groups according to PD-L1 expression results. The relationship between clinicopathological characteristics of patients with ovarian cancer and PD-L1 expression was examined. Results SUVmax was significantly higher in PD-L1-positive tumors than in PD-L1-negative tumors (16.1 +/- 5.2 and 12.7 +/- 7.0, respectively; p = 0.026). There were no significant differences in age, histologic type, and tumor grade between the PD-L1-negative and PD-L1-positive groups. The receiver operating characteristic curve analysis demonstrated that the highest accuracy (61.8%) for predicting PD-L1 expression was obtained with an SUVmax cutoff value of 10.5. Conclusion There was a significant correlation between F-18-FDG uptake and PD-L1 expression, suggesting a role of F-18-FDG PET/CT in selecting ovarian cancer candidates for anti-PD-L1 antibody therapy.