Evaluation of deep myometrial invasion in endometrial cancer patients: is dual-energy CT an option?

Objectives: Assessment of deep (>50%) myometrial invasion by dual-energy CT (DECT) and Trans-Vaginal US (TVUS) in patients with endometrial cancer. Methods: We retrospectively enrolled patients with endometrial cancer who underwent DECT and TVUS for pre-surgical staging. Three sets of images were evaluated: 70 keV (routine CT images), 50 keV, and iodine-water reconstructions. The gold standard was pathology after surgery. The agreement between the different imaging modalities and the gold standard was estimated. Sensitivity, specificity and accuracy for each imaging modality were evaluated with 95% confidence intervals (CI). Results: Thirty-nine patients were included. Median time from CT and TVUS to surgery was 23 and 18 days, respectively. The best agreement between evaluation of myometrial infiltration and the gold standard was 0.88 (0.72, 1.00) for the 50 keV images; the worst agreement was 0.43 (0.00, 0.88) for the 70 keV images. CT iodine reconstructions and US agreement were comparable. Specificity, sensitivity and accuracy were 0.91, 1.00, 0.94; 0.57, 0.86, 0.71; 0.82, 1.00, 0.87; 0.91, 0.77, 0.86 for 50 keV, 70 keV, iodine reconstructions and ultrasound, respectively. Conclusions: DECT is a promising tool for assessment of myometrial invasion in endometrial cancer patients, with a special focus on 50 keV images.