RT Journal Article SR Electronic T1 #309 Preoperative magnetic resonance imaging for evaluation of myometrial invasion in endometrial carcinoma JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A148 OP A148 DO 10.1136/ijgc-2023-ESGO.304 VO 33 IS Suppl 3 A1 Dane, Cem YR 2023 UL http://ijgc.bmj.com/content/33/Suppl_3/A148.2.abstract AB Introduction/Background Endometrium cancer is the most common gynecologic malignancy in developed countries. 70–80% of patients with endometrial cancer are Stage 1 at diagnosis. Prognosis, recurrence and survival depend mainly on the surgical stage of the tumor. In our study, we investigated the effectiveness of preoperative MRI in demonstrating myometrial invasion.Methodology In our study, endometrial cancer patients who underwent surgery in our clinic between April 2010 and April 2019 were retrospectively evaluated. A total of 123 patients who underwent MRI in the preoperative period were included in the study. Types other than Endometroid type Endometrium cancer were excluded.Results When the postoperative staging of our patients was analyzed, 59 of 69 cases with superficial myometrial invasion were correctly identified by MRI. The accuracy rate of MRI in showing superficial myometrial invasion was 85%. In addition, 85 of 112 patients identified as Stage 1 by MRI were also identified as Stage 1 after surgery. According to MRI, 24% of the stage 1 patients had a more advanced stage.Conclusion This study shows that preoperative MRI in early-stage endometrial cancer may be important in predicting the stage and thus guiding surgery. The high accuracy rate in cases with superficial myometrial invasion makes MRI valuable in patients with Stage 1 and may thus expand the use of laparoscopy in endometrial cancer. It may also reduce the need for lymphadenectomy, which may increase morbidity, in patients with Stage 1A.Disclosures I have no potential conflict of interest to report