Diagnostic accuracy of PET/CT in early stage ovarian cancer: comparison between PET/CT and CT or MRI

The purpose of this study was to compare the diagnostic accuracy of positron emission tomography/computed tomography (PET/CT), abdomino-pelvic computed tomography (CT), and pelvic magnetic resonance imaging (MRI) for detection of early stage ovarian cancer. Medical record of 140 women who underwent PET/CT scanning with suspected early stage ovarian cancer (stage 1-2) from July 2005 to February 2012 was retrospectively reviewed. Preoperative CT, MRI, and PET/CT findings were compared with histopathologic results obtained from the surgery. The accuracy of each modality in detection of malignancy was evaluated by computing the relevant areas under a receiver operating characteristics(ROC) curve and comparisons of the area under the curve (AUC) according to the modality (MedCalc® version 9.6.3.0, Broekstraat 52, 9030 Mariakerke, Belgium). Histopathology showed 7 cases of benign tumors, 23 cases of borderline tumors, and malignant tumors in 110 cases. In detecting malignant lesions in the ovaries and the adnexa, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PET/CT were higher than the corresponding values of CT or MRI. In discriminating between cases of benign/borderline and malignant, the accuracy of PET/CT (0.760) trended higher than that of CT or MRI (0.585). PET/CT is more accurate than abdomino-pelvic CT or pelvic MRI in diagnosis of early stage ovarian cancer and in differentiating between cases of benign/borderline and malignant ovarian tumors.