Diagnostic accuracy of integrated FDG-PET/contrast-enhanced CT in staging ovarian cancer: comparison with enhanced CT.

Abstract

The purpose of the study is to evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) with (18)F-fluorodeoxyglucose (FDG) with IV contrast for preoperative staging of ovarian cancer, in comparison with enhanced CT, using surgical and histopathological findings as the reference standard. Forty patients with ovarian cancer underwent FDG-PET/contrast-enhanced CT scans for staging before primary debulking surgery. PET/CT and the CT component separately, were interpreted by two experienced radiologists by consensus for each investigation. Status with regard to lesion inside and outside the pelvis was determined on the basis of histopathology. The significance of differences between the two imaging modalities was determined using the McNemar test. Staging revealed stage I in 18 patients (IA, n=9; IB, n=3; IC, n=6), stage II in seven (IIA, n=2; IIB, n=3; IIC, n=2), stage III in 14 (IIIA, n=1; IIIB, n=3; IIIC, n=10), and stage IV in one. The results of CT and PET/CT were concordant with the final pathological staging in 22 out of 40 (55%) and 30 out of 40 (75%) cases, respectively. The overall lesion-based sensitivity improved from 37.6% (32 out of 85) to 69.4% (59 out of 85), specificity from 97.1% (578 out of 595) to 97.5% (580 out of 595), and accuracy from 89.7% (610 out of 680) to 94.0% (639 out of 680) between CT and PET/CT. There were significant differences in sensitivity and accuracy, with p values of 5.6 x 10(-7) and 1.2 x 10(-7), respectively. Integrated FDG-PET/contrast-enhanced CT is a more accurate imaging modality for staging ovarian cancer and useful for selecting appropriate treatment than enhanced CT.