EP479 Agreement between magnetic resonance imaging, transvaginal ultrasound scan and intraoperative biopsy for determining miometrial infiltration in endometrial carcinoma. Tertiary centre results

Introduction/Background Miometrial infiltration (MI) is one of the most important prognosis features for endometrial carcinoma (EC). Different methods have been extensively used with the aim of optimize the detection of MI, such us magnetic resonance imaging (MRI), transvaginal ultrasound scan (TUS) and intraoperative frozen section with different results. The aim of our study is to review the diagnostic accuracy of these methods in the preoperative detection of MI in our institution and compare it with the available data. Methodology Retrospective unicentric study of 271 patients with EC diagnosed, treated and followed-up at Hospital Universitario 12 de Octubre (Madrid, Spain) between 2008 and 2018. Results Demographic characteristics of the study population are described in table 1. Results of sensitivity, specificity, positive predictive value, negative predictive value and validity of the different methods compared with definitive histopathological diagnosis of MI (used as the gold standard) are registered in table 2. Conclusion Surgical staging represents the cornerstone in the treatment of EC. Therapeutic role of lymphadenectomy still remains nowadays a controversial issue. Different methods have been used to detect preoperatively those patients with lower risk of lymph node involvement in order to avoid lymphadenectomy. MI is considered as an essential fact when establishing the endometrial carcinoma prognosis. On one side, it determines the modification of the stage during initial staging. On the other side, it has been associated with a higher risk for lymph nodes dissemination, haematogenous spread, higher recurrence rates and lower overall survival rates. In our institution, preoperative imaging studies present an acceptable accuracy for diagnosis of MI according to the available data, but the test with the highest sensitivity and specificity continues to be the histopathological study of intraoperative frozen section. Further studies are needed in order to establish the better approach to determinate preoperative MI. Disclosure Nothing to disclose.