The role of 3.0 tesla diffusion-weighted magnetic resonance imaging in evaluating the depth of myometrial invasion and predicting the histological grade of endometrial cancer

To assess the depth of myometrial invasion in patients with endometrial cancer by contrasting the diagnostic efficacy of dynamic contrast enhanced (DCE) magnetic resonance imaging with diffusion-weighted (DWI) MRI. 64 Patients with endometrial cancer who had preoperative 3.0 Tesla MRI in sagittal planes, including T2-weighted (T2W), DWI (b=0 and 1000 s/mm2), and dynamic contrast enhanced (DCE) MRI, were retrospectively evaluated. Results of surgical pathology were linked with the depth of myometrial invasion on MRI. A radiologist determined the definitive histologic grade (G1-G2; G3) and compared it with the mean ADC of the tumor and peritumoral zone. The evaluation of myometrial invasion was enhanced when using DWI or DCE imaging values were combined with T2W imaging. Sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and area under the receiver operating characteristic (ROC) curve were measured for determining the depth of myometrial invasion: T2W-DWI / T2W-DCE imaging; 96.15%/92.31%, 85.19%/85.19%, 90.57%/86.68%, 86.21%/85.71%, 95.81%/92%, and 0.91/0.89. The average ADC offered accurate and valuable information for estimating the tumors’ histopathological grade. The area under the ROC curve, sensitivity, specificity, accuracy, negative predictive value, and positive predictive value in our series were 64%, 87.18%, 76.19%, 79.07%, 78.13%, and 0.763, respectively, for a cutoff value of 0.638 x 10-3 mm2/s. T2W-DWI is a potential replacement for DCE in the assessment of the depth of myometrial invasion of endometrial cancer, especially useful for patients with contraindications to contrast agents. The combination of T2W and DWI has high diagnostic high accuracy in the assessment of the depth of myometrial invasion.