David G Hewett1, Tonya Kaltenbach2, Yasushi Sano3, Shinji Tanaka4, Brian P Saunders5, Thierry Ponchon6, Roy Soetikno2, Douglas K Rex7. 1. Indiana University School of Medicine, Indianapolis, Indiana; The University of Queensland School of Medicine, Brisbane, Australia. 2. Veterans Affairs Palo Alto Health Care System, Palo Alto, California; Stanford University School of Medicine, Stanford, California. 3. Sano Hospital, Kobe, Japan. 4. Hiroshima University, Hiroshima, Japan. 5. Wolfson Unit for Endoscopy and Imperial College London, St. Marks Hospital, London, United Kingdom. 6. Hôpital Edouard-Herriot, Lyon, France. 7. Indiana University School of Medicine, Indianapolis, Indiana. Electronic address: drex@iupui.edu.
Abstract
BACKGROUND & AIMS: Almost all colorectal polyps ≤ 5 mm are benign, yet current practice requires costly pathologic analysis. We aimed to develop and evaluate the validity of a simple narrow-band imaging (NBI)-based classification system for differentiating hyperplastic from adenomatous polyps. METHODS: The study was conducted in 4 phases: (1) evaluation of accuracy and reliability of histologic prediction by NBI-experienced colonoscopists; (2) development of a classification based on color, vessels, and surface pattern criteria, using a modified Delphi method; (3) validation of the component criteria by people not experienced in endoscopy or NBI analysis (25 medical students, 19 gastroenterology fellows) using 118 high-definition colorectal polyp images of known histology; and (4) validation of the classification system by NBI-trained gastroenterology fellows, using still images. We performed a pilot evaluation during real-time colonoscopy. RESULTS: We developed a classification system for the endoscopic diagnosis of colorectal polyp histology and established its predictive validity. When all 3 criteria were used, the specificity ranged from 94.9% to 100% and the combined sensitivity ranged from 8.5% to 61.0%. The specificities of the individual criteria were lower although the sensitivities were higher. During real-time colonoscopy, endoscopists made diagnoses with high confidence for 75% of consecutive small colorectal polyps, with 89% accuracy, 98% sensitivity, and 95% negative predictive values. CONCLUSIONS: We developed and established the validity of an NBI classification system that can be used to diagnose colorectal polyps. In preliminary real-time evaluation, the system allowed endoscopic diagnoses of colorectal polyp histology.
BACKGROUND & AIMS: Almost all colorectal polyps ≤ 5 mm are benign, yet current practice requires costly pathologic analysis. We aimed to develop and evaluate the validity of a simple narrow-band imaging (NBI)-based classification system for differentiating hyperplastic from adenomatous polyps. METHODS: The study was conducted in 4 phases: (1) evaluation of accuracy and reliability of histologic prediction by NBI-experienced colonoscopists; (2) development of a classification based on color, vessels, and surface pattern criteria, using a modified Delphi method; (3) validation of the component criteria by people not experienced in endoscopy or NBI analysis (25 medical students, 19 gastroenterology fellows) using 118 high-definition colorectal polyp images of known histology; and (4) validation of the classification system by NBI-trained gastroenterology fellows, using still images. We performed a pilot evaluation during real-time colonoscopy. RESULTS: We developed a classification system for the endoscopic diagnosis of colorectal polyp histology and established its predictive validity. When all 3 criteria were used, the specificity ranged from 94.9% to 100% and the combined sensitivity ranged from 8.5% to 61.0%. The specificities of the individual criteria were lower although the sensitivities were higher. During real-time colonoscopy, endoscopists made diagnoses with high confidence for 75% of consecutive small colorectal polyps, with 89% accuracy, 98% sensitivity, and 95% negative predictive values. CONCLUSIONS: We developed and established the validity of an NBI classification system that can be used to diagnose colorectal polyps. In preliminary real-time evaluation, the system allowed endoscopic diagnoses of colorectal polyp histology.