Preoperative Local Staging of Endometrial Cancer: Transvaginal Sonography vs. Magnetic Resonance Imaging

OBJECTIVES: To compare the accuracy of transvaginal sonography (TVS) and magnetic resonance imaging (MRI) in the preoperative staging of endometrial carcinoma. METHODS: This was a prospective study in which 74 women consecutively diagnosed with endometrial carcinoma were examined using TVS by physicians trained in gynecological sonography and MRI by radiologists with a special interest in gynecology. All patients underwent surgical-pathological staging after removal of the uterus, adnexa and pelvic lymph nodes. Sensitivity, specificity, and positive and negative predictive values were calculated for each imaging modality with regard to detection of neoplastic invasion of the outer half of the myometrium and cervical involvement. RESULTS: TVS and MRI performed equally well in the preoperative staging of endometrial cancer, with no statistically significant differences between the two techniques. The sensitivity, specificity, positive and negative predictive values, and overall diagnostic accuracy for TVS in the evaluation of myometrial infiltration were 84%, 83%, 79%, 88% and 84%, respectively. Respective values for MRI were 84%, 81%, 77%, 87% and 82%. The corresponding statistics for detection of cervical involvement were 93%, 92%, 72%, 98% and 92% for TVS; and 79%, 87%, 58%, 95% and 85% for MRI. CONCLUSIONS: When carried out by expert practitioners, TVS shows good accuracy in the local staging of endometrial carcinoma. Because of its high costs, MRI should be offered only to those in whom TVS produces images of poor quality.