Objective: This study aimed to assess the diagnostic efficacy of the ovarian adnexal reporting and data system (O-RADS) and ultrasound (US) and its sub-classification system for distinguishing ovarian masses.
Methods: O-RADS US was used for the retrospective analysis of 606 ovarian masses of Chinese from 2 medical centres by 2 gynaecologic sonographers with varying experience. The O-RADS 4 categories masses were further sub-classified into O-RADS 4a and O-RADS 4b through 3 different approaches (O-RADS A1/A2/A3).
Results: The AUC of O-RADS US for differentiating benign from malignant ovarian masses was 0.927 (95% CI, 0.903-0.946, P < .001). The optimal cut-off value for predicting malignancy was >O-RADS 3, with sensitivity and specificity of 98.60% and 68.90%, respectively. The diagnostic efficacy of the 3 sub-classification systems surpassed that of O-RADS US (P < .05). Specifically, A2 approach (within O-RADS 4 lesions, unilocular and multilocular cysts with solid components were sub-classified as O-RADS 4b, whereas the remaining O-RADS 4 lesions were sub-classified as O-RADS 4a) resulted in an AUC of 0.942 (95% CI, 0.921-0.960, P < .001). The best cut-off value predicting malignancy was >O-RADS 4a, exhibiting relatively high specificity (82.51%) and maintaining a high sensitivity (93.01%).
Conclusion: The diagnostic efficacy of O-RADS US for identifying ovarian tumours is good, but specificity is slightly lower. This study enhanced diagnostic specificity after subclassifying O-RADS 4 lesions, especially A2 approach. It holds significant clinical value for Chinese women and merits further clinical promotion and application.
Advances in knowledge: The sub-classification of O-RADS US allows better identifying ovarian tumours, facilitating informed preoperative clinical management and diagnosis.
Keywords: O-RADS; diagnostic efficacy; ovarian masses; sub-classification system; ultrasound.
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