Accuracy of narrow-band imaging in predicting colonoscopy surveillance intervals and histology of distal diminutive polyps: results from a multicenter, prospective trial

Abstract

In vivo prediction of colorectal polyp histology by narrow-band imaging (NBI) could potentially avoid post-polypectomy histologic examination or resection of diminutive lesions, thereby reducing costs and risk. To assess whether NBI is able to predict colonoscopy surveillance intervals and histology of distal diminutive polyps according to American Society for Gastrointestinal Endoscopy (ASGE) criteria. Prospective, multicenter study. Five endoscopic centers. Consecutive patients undergoing colonoscopy in 5 centers were included. Participating endoscopists were required to pass a before-study qualifying examination. Histology of polyps that were <10 mm was predicted at NBI and assigned a designation of high or low confidence. Accuracy of high-confidence NBI prediction for polyps ≤5 mm in predicting surveillance intervals and negative predictive value (NPV) for adenomatous histology in the rectosigmoid colon were compared with the ASGE thresholds (90% agreement, 90% NPV). A total of 278 patients (mean age, 63 years; 58% male) were enrolled. At colonoscopy, 574 (97.3%) polyps <10 mm (429 ≤5 mm, 60% adenomatous) were retrieved for histologic analysis. Sensitivity, specificity, positive and negative predictive values, and accuracy of high confidence-NBI predictions for adenomatous histology in lesions ≤5 mm were 90%, 88%, 89%, 89%, and 89%, respectively. High-confidence characterization of polyps ≤5 mm predicted the correct surveillance interval in 92% to 99% of cases, according to the American and European guidelines. NPV of high-confidence NBI for adenomatous histology for the rectosigmoid colon lesions ≤5 mm was 92%. Only experienced endoscopists were included. High-confidence prediction of histology for polyps ≤5 mm appears to be sufficiently accurate to avoid post-polypectomy histologic examination of the resected lesions as well as to allow rectosigmoid hyperplastic polyps to be left in place without resection. ( NCT01675752.).