Introduction/Background Patients with advanced ovarian cancer (AOC) diagnosis will often undergo bowel resection when primary or interval debulking surgery is performed. Properly identifying these cases is crucial to establish an accurate operative strategy and to proportionate precise information to patients, since intestinal surgery implies higher morbidity, and surgical time and complexity.

Transvaginal Ultrasound (TVUS) is gaining interest as a tool to evaluate preoperative disease pelvic extension, especially tumour rectosigmoid infiltration.

Our objective was to assess the diagnostic accuracy of TVUS in predicting rectosigmoid infiltration and therefore the need of an intestinal resection in patients with AOC.

Methodology Observational prospective study in our centre between April 2021 and April 2023. Women with suspected diagnostic of ovarian cancer with a pre-treatment TVUS and final AOC (stage IIB-IV) diagnosis confirmed histologically after primary or interval debulking surgery were included.

TVUS was performed before primary debulking surgery and after neoadyuvancy in interval surgery. Preoperative TVUS findings and prediction of rectosigmoid resection were compared to surgical procedures finally performed, and sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

Results 64 patients met inclusion criteria and were included for analysis. Preoperative TVUS identified rectosigmoid infiltration suggestive of requiring bowel resection in 24 of 64 women. In this group, the sonographic findings of 18 women were confirmed during surgery and had to undergo rectosigmoid resection. TVUS properly ruled out rectosigmoid infiltration in 33 patients with only 2 false negatives cases. Sensitivity, specificity, PPV and NPV were 90%, 85%, 75% and 94% respectively.

Sonographic rectosigmoid assessment was not valuable in 5 patients, mostly because of large adnexal tumours or abundant intestinal content.

Conclusion Preoperative TVUS performed by a trained sonographer in AOC could be useful to identify patients with rectosigmoid infiltration and to predict the need of bowel resection, which implies better pre-surgical evaluation and planification.

Disclosures The authors declare no conflict of interest.