Accuracy of in vivo optical diagnosis of colon polyp histology by narrow-band imaging in predicting colonoscopy surveillance intervals

BackgroundThe American Society for Gastrointestinal Endoscopy (ASGE) recently developed thresholds for the performance characteristics of technologies for real-time assessment of histology of diminutive (≤5 mm) colon polyps. Narrow-band imaging (NBI) has been shown to predict polyp histology with moderate to high accuracy in several studies.ObjectiveTo determine whether in vivo optical diagnosis of polyp histology by using NBI can reach the 2 benchmarks set forth by the ASGE.DesignRetrospective analysis of data from 3 prospective clinical trials.SettingTwo tertiary referral centers.PatientsSubjects undergoing screening or surveillance colonoscopy.InterventionsIn vivo optical diagnosis of polyp histology by using NBI.Main Outcome MeasurementAccuracy in predicting colonoscopy surveillance intervals, negative predictive value (NPV) for diagnosing adenomatous histology in the rectosigmoid.ResultsA total of 410 patients met the inclusion/exclusion criteria and had at least 1 polyp seen and resected during colonoscopy. Using in vivo optical diagnosis instead of histopathology for all diminutive polyps predicted the correct colonoscopy surveillance interval in 86% to 94% patients. When optical diagnosis was limited to diminutive polyps in the rectosigmoid only, the NPV for diagnosing adenomatous histology with NBI was 95%.LimitationsRetrospective analysis from tertiary referral centers.ConclusionsThe threshold NPV for diagnosing adenomatous histology in diminutive rectosigmoid polyps recently set forth by the ASGE can be achieved by using NBI. The threshold accuracy rate for predicting surveillance interval recommendations can be reached by using NBI, but only if patients with 1 to 2 small adenomas without advanced features have a repeat colonoscopy in 10 years.