Performance of FDG-PET/CT in the diagnosis of recurrent endometrial cancer

Objective: To evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) using 18-F-fluorodeoxyglucose (FDG), compared with PET alone, in the diagnosis of suspected endometrial cancer recurrence. Methods: Thirty women who had undergone primary surgery for histopathologically proven endometrial cancer with suspected recurrence because of clinical, cytological, biochemical, and/or radiological findings were enrolled in this study. PET and integrated PET/CT images were evaluated by two different experienced radiologists by consensus for each modality. A final diagnosis of recurrence was confirmed by histopathology, other imaging and clinical follow-up for longer than 1 year. The statistical significance of differences between PET and PET/CT was determined by the McNemar test. Results: Patient-based analysis showed that the sensitivity, specificity, and accuracy of PET/CT were 93% (14/15), 93% (14/15), and 93% (28/30), respectively, whereas for PET, the corresponding data were 80% (12/15), 80% (12/15), and 80% (24/30), respectively (P = 0.479, 0.479, and 0.134, respectively). CT from PET/CT resolved the false-positive PET results because of hyper-metabolic activity of benign inflammatory lesions and physiological variants and moreover detected lung metastasis and para-aortic lymph node metastasis that PET missed. However, tiny para-aortic lymph node metastasis could not be detected even with PET/CT. Conclusions: Integrated FDG-PET/CT is a useful complementary modality for providing good anatomic and functional localization of sites of recurrence during follow-up of patients with endometrial cancer.