Positive margin rates and predictors in transoral robotic surgery after federal approval: A national quality study.

National PMR is 16.9%, substantially higher than reported in high-volume TORS centers. There is a linear association between positive margins and T classification, with T3 and T4 PMRs exceeding 28%. High-volume facilities are half as likely to yield positive margins compared to low-volume facilities. There was no association between human papilloma virus status, tumor subsite, or academic facility status and positive margins.