The effectiveness of dual-phase 18F-FDG PET/CT in the detection of epithelial ovarian carcinoma: a pilot study

BACKGROUND The aim of our study is to establish the potential role of dual-phase 18F-fluorodeoxyglucose positron emission tomography / computed tomography (FDG-PET/CT) in patients presenting ovarian masses with diffuse peritoneal infiltration for differentiating benign from malignant lesions. METHODS Twenty patients (13 with ovarian cancers and 7 with benign lesions) were evaluated preoperatively by dual-phase 18F-FDG-PET/CT performed 1 h and 2 h after injection of 18F-FDG. The maximum standardized uptake value (SUVmax) for both time points SUVmax1 and SUVmax2 were determined, respectively, and the retention index (RI) was calculated by subtracting the SUVmax1 from the SUVmax2 and dividing by SUVmax1. RESULTS The areas under the receiver operating characteristic curves (AUCs) of SUVmax1 and SUVmax2 were 0.753 (P = 0.062, 95% confidence interval [CI] = 0.512-0.915) and 0.835 (P = 0.001, 95% CI = 0.604-0.961), respectively. The AUC of the RI was 0.901 (P < 0.001, 95% CI = 0.684-0.988). Using pairwise comparisons, the AUC of SUVmax2 was significantly higher than that of SUVmax1 (P = 0.032). The AUC of the RI was higher than those of SUVmax1 and SUVmax2, but the difference was not statistically significant. CONCLUSION Dual-phase 18F-FDG PET/CT might be considered when preoperative imaging is indeterminate. A larger-scaled, prospective study is needed to verify these results.