The learning curve and difficult points of the O-RADS ultrasound risk stratification system in 54 trainees.

Purpose: This study aimed to evaluate the learning curve and explore the difficult points of the Ovarian-Adnexal Reporting and Data System (O-RADS) ultrasound risk stratification system.

Methods: One hundred adnexal masses (AMs) were randomly selected for five tests as training data. Two experienced trainers had an inter-rater agreement of 0.95 for the O-RADS scores. Fifty-four trainees (26 level I practitioners [group 1], 17 level II practitioners [group 2], and 11 experienced level II practitioners [group 3]) attended the training. Every trainee received assessment and feedback after 20 scored cases. The outcomes of the five tests were compared among the three groups using repeated-measurements analysis of variance.

Results: Of the 100 AMs, 52 were pathologically benign and 48 were malignant; the O-RADS scores were 2, 3, 4, and 5 in 22, 11, 48, and 19 AMs, respectively. The between-subjects effects test showed no significant differences between groups 1, 2, and 3 for the five tests (P=0.501). For each group, the differences among the five tests were significant (P<0.001, P=0.006, and P=0.044 for groups 1, 2, and 3, respectively). Test 2 was the worst. In 23 cases, more than 40% of trainees gave incorrect answers, which mainly related to classic benign lesions, the color flow score, and solid-appearing masses.

Conclusion: After training, junior doctors at different levels can reach a coincident O-RADS ultrasound risk stratification. The difficulties primarily related to subjective judgments of classic benign lesions, the color flow score, and solid-appearing masses. More experience is needed to improve the applicability of the system.