Diagnostic accuracy of 18F-FDG PET/CT scan for peritoneal metastases in advanced ovarian cancer

Background: To assess the diagnostic accuracy of F-18-FDG PET/CT to determine the Eisenkop score and peritoneal cancer index (PCI) in correlation with surgical findings. Methods: Forty-three patients underwent preoperative F-18-FDG PET/CT scan, followed by primary cytoreductive surgery for advanced ovarian cancer between September 2015 and February 2018. Clinical data were prospectively collected, including intraoperative assessment (with Eisenkop and PCI scores) and surgical results. The sensitivity, specificity, and accuracy were calculated at each anatomical site. The Eisenkop score, PCI score, and tumor volume of PET/CT scans were compared with surgical findings. Results: A total of 32 (74.4%) patients were diagnosed with stage III, and 11 (25.6%) patients were stage IV. Among these individuals, 19 (44.2%) patients had no residual disease after primary surgery. The median [range] Eisenkop score on PET/CT scans and surgical findings were 5 [1-13] and 6 [2-13], respectively. PET/CT scans correctly predicted the Eisenkop score with high sensitivity (84.2%), specificity (87.0%), and accuracy (85.1%). The diagnostic accuracy of PET/CT scans for PCI scores was lower (78.5%), with 72.7% sensitivity and 84.9% specificity. Preoperative PET/CT scans might underestimate tumor volume compared with surgical findings. Conclusions: F-18-FDG PET/CT scans accurately predicted peritoneal metastases in advanced ovarian cancer before surgery using Eisenkop score.