Computer-assisted optical diagnosis of colorectal polyps up to 10 mm

Background: Computer-aided diagnosis (CADx) of colorectal polyps during colonoscopy could replace pathology for certain polyps. This study aimed to evaluate CADx-assisted optical diagnosis for polyps of ≤10 mm in the context of established quality benchmarks. Methods: We performed a post-hoc analysis of a randomized controlled trial evaluating assistive versus autonomous computer-aided optical diagnosis. Our primary outcome was achievement of the American Society for Gastrointestinal Endoscopy PIVI1 threshold for resect-and-discard implementation when CADx was used for polyps ≤3 mm. Secondary outcomes included PIVI1 threshold achievement when using CADx with a size cutoff of ≤5 mm and ≤10 mm, as well as diagnostic performance and prevalence of advanced histology across the polyp size groups. Results: We included 313 patients with a total of 463 polyps of ≤10 mm undergoing optical diagnosis with CADx assistance. Compared with pathology-based intervals, surveillance interval agreement was 94.6% (95%CI 91.3%–96.7%), 89.5% (95%CI 85.4%–92.5%), and 85.9% (95%CI 81.5%–89.5%) when CADx was used with size cutoffs ≤3 mm, ≤5 mm, and ≤10 mm, respectively. The diagnostic accuracy of CADx-assisted optical diagnosis was 76.2%, 76.6%, and 72.5% for polyps sized ≤3 mm, >3 to ≤5 mm, and >5 to ≤10 mm, respectively. The negative predictive value for rectosigmoid adenomas was >90% for all size groups (PIVI2). The prevalence of advanced or serrated pathology was higher in polyps >3 mm, which resulted in a higher number of incorrectly assigned surveillances intervals. Conclusions: In our study, CADx-assisted optical diagnosis met the resect-and-discard PIVI1 threshold only with a size cutoff of ≤3 mm, and the diagnose-and-leave PIVI2 threshold for polyps ≤10 mm.