Comparison of the Diagnostic Performances of Ultrasound-Based Models for Predicting Malignancy in Patients With Adnexal Masses

Aim This study aimed to compare different ultrasound-based International Ovarian Tumor Analysis (IOTA) prediction models, namely, the Simple Rules (SRs) the Assessment of Different NEoplasias in the adneXa (ADNEX) models, and the Risk of Malignancy Index (RMI), for the pre-operative diagnosis of adnexal mass. Methods This single-centre diagnostic accuracy study involved 486 patients. All ultrasound examinations were analyzed and the prediction models were applied. Pathology was the clinical reference standard. The diagnostic performances of prediction models were measured by evaluating receiver-operating characteristic curves, sensitivities, specificities, positive and negative predictive values, positive and negative likelihood ratios, and diagnostic odds ratios. Results To discriminate benign and malignant tumors, areas under the ROC curves (AUCs) for ADNEX models were 0.94 (95% CI: 0.92-0.96) with CA125 and 0.94 (95% CI: 0.91-0.96) without CA125, which were significantly higher than the AUCs for RMI I-III: 0.87 (95% CI: 0.83-0.90), 0.83 (95% CI: 0.80-0.86), and 0.82 (95% CI: 0.78-0.86), (all P < 0.0001). At a cut-off of 10%, the ADNEX model with CA125 had the highest sensitivity (0.93; 95% CI: 0.87-0.97) compared with the other models. The SRs model achieved a sensitivity of 0.93 (95% CI: 0.86-0.97) and a specificity of 0.86 (95% CI: 0.82-0.89) when inconclusive diagnoses (11.7%) were classified as malignant. Conclusion ADNEX and SRs models were excellent at characterising adnexal masses which were superior to the RMI in Chinese patients.