Could A 2d/3d Us Based Model Be Helpful In The Assessment Of Myometrial Invasion At Time Of Intraoperative Frozen Section? A Pilot Study

BACKGROUND: The assessment of myometrial invasion is a pivotal step in the preoperative staging of endometrial cancer. Intraoperative frozen section (FS) represents a reliable tool in directing surgeon's choices. Preoperative transvaginal ultrasound (US) showed high accuracy in evaluating myometrial invasion. This study aimed to understand if the application of a standardized ultrasonographic protocol for the pre-operative evaluation of myometrial invasion can help pathologists in improving the accuracy of FS. Furthermore, the agreement between US and FS in the assessment of myometrial invasion was assessed.METHODS: Sixty-six patients who underwent surgery for endometrial cancer were analyzed. Preoperative 2D/3D ultrasound was performed in all the patients. Myometnal invasion was estimated by subjective assessment and objective measurement techniques. Data from US were reported to pathologists through a prefilled form with depth and site of the maximum myometrial invasion. Diagnostic performance of US and FS were compared having the definitive histological examination as the gold standard.RESULTS: Influenced by the information given by our 3D US-model, FS showed a 90% sensitivity and a 93% specificity, with a 93% PPV and an 89% NPV. The agreement with histology was strong (K=0.824 ). Myometnal invasion was missed at the level of the isthmus by FS just in one case. Subjective assessment was confirmed as the most reliable ultrasono-graphic technique in assessing myometrial invasion, with 90% sensitivity. 78% specificity, 80% PPV and 89% NPV. The agreement with histology was substantial (K.68).CONCLUSIONS: The application of a preoperative 2D/3D US assessment would seem to help pathologists in detecting myometrial invasion in difficult areas of the uterus such as the isthmus, reducing downstaging and overtreatment.