Objective: To evaluate the diagnostic accuracy of preoperative transvaginal sonography in the detection of myometrial invasion in endometrial cancer classified by the grade of disease. Design: Prospective multicenter study. Setting: Department of Obstetrics and Gynaecology, Medical Faculty, Palacky University, Olomouc, Czech Republic. Methods: In the period 1998 - 2001, 195 patients from 10 cooperating centers in the Czech Republic were enrolled in the RHOCE (risk of hysteroscopy in endometrial cancer) study. Sixteen patients did not meet the vaginal sonography study criteria (insufficent surgical staging, missing ultrasound examination). Sonographic results in 179 patients were categorized as M0 - absence of infiltration (n = 97), M1 - infiltration less than 1/2 myometrial depth (n = 61), M2 - infiltration greater than 1/2 myometrial depth (n = 21). The final histopathology report of myoinvasion was used as a golden standard. Results: We proved lower accuracy of vaginal sonography in detecting myometrial invasion in patients with higher grade of disease. Conclusion: Based on these data, the value of preoperative vaginal sonography as the sole criterion in the decision to perform extensive surgical procedures is questionable and warrants further evaluation.

        Key words: endometrial cancer, myometrial invasion, vaginal sonography, preoperative assessment