Prospective comparative trial comparing O-RADS, IOTA ADNEX model, and RMI score for preoperative evaluation of adnexal masses for prediction of ovarian cancer

Introduction: Preoperative assessment of ovarian tumors to distinguish between benign and malignant is important. At this time, many diagnostic models were available and the popularity of the risk of malignancy index (RMI) in Thailand is still high. The IOTA Assessment of Different NEoplasias in adneXa (ADNEX) model and the Ovarian-Adnexal Reporting and Data System (O-RADS) model were both new models with good performance. Objectives: The purpose of this study was to compare O-RADS, RMI, and ADNEX models. Design: This diagnostic study was performed using data from the prospective study. Methods: Data from 357 patients from a previous study were included and calculated using the RMI-2 formula then applied to the O-RADS system and the IOTA ADNEX model. The diagnostic significance of the results was evaluated by receiver operating characteristic (ROC) analysis and pairwise comparison between models was made. Results: The area under the receiver operating characteristic curve (AUC) to distinguish an adnexal mass as a benign or malignant tumor was 0.975 (95% CI, 0.953–0.988) for the IOTA ADNEX model; 0.974 (95% CI, 0.960–0.988) for O-RADS; 0.909 for RMI-2 (95% CI, 0.865–0.952). There were no differences in pairwise AUC comparisons between the IOTA ADNEX and O-RADS models, and both were better than those of RMI-2. Conclusions: The IOTA ADEX and O-RADS models are excellent tools for distinguishing the adnexal mass in the preoperative assessment and were better than RMI-2. The use of one of these models is recommended.