Development and validation of a predictive nomogram for stratifying risk in uterine mesenchymal tumors based on clinical and multiparametric ultrasound characteristics

To develop and validate a nomogram model integrating clinical and multiparametric ultrasound features for the preoperative differentiation of uterine sarcoma from atypical uterine leiomyoma. A total of 46 patients with uterine sarcoma and 239 patients with atypical uterine leiomyoma were retrospectively enrolled and randomly assigned to training and test sets at a 7:3 ratio. Univariable analysis followed by multivariable logistic regression was performed to screen independent predictors. We then developed the clinical and conventional ultrasound (Clin-US) and clinical and multiparametric ultrasound (Clin-MPUS) nomograms and compared their predictive performance with that of the Basel Sarcoma Score (BSS). Model performance was assessed using the area under the curve (AUC), calibration curves, and decision curve analysis (DCA). Optimism-bias correction was performed using 1000 bootstrap resampling iterations. In both the training and test sets, the Clin-MPUS nomogram achieved higher AUCs (0.891 and 0.858; bootstrap-corrected: 0.873) than the Clin-US model (0.865 and 0.829; bootstrap-corrected: 0.843), and both nomograms significantly outperformed the BSS (0.716 and 0.688; all P < 0.05). After the incorporation of contrast-enhanced ultrasonography (CEUS) parameters, the net reclassification improvement (NRI) and integrated discrimination improvement (IDI) increased significantly (P < 0.05). Further stratification of the high-risk group according to menopausal status improved the specificity from 84.94% to 92.05% and reduced the unnecessary intervention rate (NIR) from 46.75% to 32.20%. Taking 100 model-positive high-risk patients as an example, this approach could avert approximately 14 unnecessary surgeries for benign lesions. The Clin-MPUS nomogram showed better discriminative performance in differentiating uterine sarcoma from atypical leiomyoma than the Clin-US nomogram and BSS scoring. Further stratification according to menopausal status greatly lowered the rate of unnecessary clinical interventions, thereby offering a practical tool for personalized preoperative decision-making.