Performance of integrated FDG-PET/contrast-enhanced CT in the diagnosis of recurrent uterine cancer: Comparison with PET and enhanced CT

Purpose: To evaluate the accuracy of integrated positron emission tomography and computed tomography (PET/CT) with iodinated contrast agent and ¹⁸F-fluorodeoxyglucose (FDG) in the diagnosis of suspected uterine cancer recurrence and to assess the impact of PET/CT findings on clinical management, compared with PET alone and enhanced CT alone. Methods: Of 103 women who had undergone treatment for histopathologically proven uterine cervical or endometrial cancer, 90 underwent FDG-PET/contrast-enhanced CT examination for suspected recurrence. PET-alone, CT-alone, and fused PET/CT images were interpreted by two radiologists by consensus for each investigation. Lesion status was determined on the basis of histopathology, radiological imaging and clinical follow-up for longer than 6 months. Differences among the three modalities were tested using the Cochran Q test, followed by multiple comparisons using the McNemar test with Bonferroni adjustment. Results: Patient-based analysis showed that the sensitivity, specificity, and accuracy of PET alone were 79.5% (35/44), 73.9% (34/46), and 76.7% (69/90), respectively, whereas those of CT alone were 68.2% (30/44), 87.0% (40/46), and 77.8% (70/90), respectively, and those of PET/CT were 90.9% (40/44), 93.5% (43/46), and 92.2% (83/90), respectively. PET/CT findings resulted in a change of management in 38 of the 90 patients (42%) with an additional effect on patient management in 13 patients (14%) diagnosed by CT alone and 14 patients (16%) diagnosed by PET alone. Conclusion: FDG-PET/contrast-enhanced CT is a more accurate modality for assessing recurrence of uterine cancer, and led to more appropriate subsequent clinical management than that resulting from PET alone or enhanced CT alone.