Diagnostic value of 18 F-FDG PET/MRI for staging in patients with endometrial cancer

Background Preoperative accurate assessment of endometrial cancer can assist in the planning of additional surgical options, and in predicting the prognosis. The aim of the present study was to evaluate the diagnostic potential of non-contrast PET/MRI with 18 F-fluorodeoxyglucose ( 18 F-FDG) for assessment in preoperative staging of endometrial cancer. Methods Thirty-six patients with biopsy-proven endometrial cancer underwent preoperative 18 F-FDG PET/MRI, contrast-enhanced CT (ceCT) and pelvic dynamic contrast-enhanced MRI (ceMRI) for initial staging. The diagnostic performance of 18 F-FDG PET/MRI and ceMRI for assessing the extent of the primary tumor (T stage), and 18 F-FDG PET/MRI and ceCT for assessing nodal (N stage) and distant (M stage) metastasis, was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. The McNemar test was employed for statistical analysis. Results Accuracy for T status was 77.8 and 75.0% for 18 F-FDG PET/MRI and ceMRI, respectively. Patient-based accuracy for detecting regional nodal and distant metastasis was 91.3 and 81.8% for 18 F-FDG PET/MRI, and 87.0 and 81.8% for ceCT. None of these parameters was statistically significant ( p > 0.05). Lesion-based sensitivity, specificity and accuracy for detecting regional nodal metastasis were 100, 96.9 and 97.0% for 18 F-FDG PET/MRI, and 14.3, 97.6 and 93.3% for ceCT; sensitivity was statistically significant ( p < 0.05). Conclusions Non-contrast 18 F-FDG PET/MRI, which combines the individual advantages of PET and MRI, offers a high diagnostic value equivalent to that of ceMRI for assessment of the primary tumor, and equivalent to that of ceCT for the assessment of nodal and distant metastatic staging, in patients with endometrial cancer. These findings suggest that 18 F-FDG PET/MRI might provide an alternative diagnostic strategy to conventional imaging modalities in the preoperative staging of endometrial cancer.