Raf Bisschops1, Talat Bessissow2, Evelien Dekker3, James E East4, Adolfo Para-Blanco5, Krish Ragunath5, Pradeep Bhandari6, Matt Rutter7, Erik Schoon8, Ana Wilson9, Jestinah Mahachie John10, Kristel Van Steen10, Filip Baert11, Marc Ferrante1. 1. Department of Gastroenterology and Hepatology, University Hospital Leuven, Leuven, Belgium. 2. Division of Gastroenterology, Royal Victoria Hospital, McGill University Health Center, Montreal, Quebec, Canada. 3. Department of Gastroenterology and Hepatology, Amsterdam Medical Center, Amsterdam, The Netherlands. 4. Translational Gastroenterology Unit, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom. 5. NIHR Nottingham Digestive Diseases Biomedical Research Unit City Hospital Campus, Nottingham University Hospitals NHS Trust, Nottingham, United Kingdom. 6. Department of Gastroenterology, Spire Portsmouth Hospital, Portsmouth, United Kingdom. 7. Department of Gastroenterology, University Hospital of North Tees, Stockton-on-Tees, Cleveland, United Kingdom, and School of Medicine, Durham University, Durham, United Kingdom. 8. Department of Gastroenterology, Catherina Hospital, Eindhoven, The Netherlands. 9. Wolfson Unit for Endoscopy, St. Mark's Hospital, London, United Kingdom. 10. Medical Genomics Unit, BIO3, GIGA-R, University of Liège, Liège, Belgium. 11. Department of Gastroenterology, AZ Delta, Roeselare, Belgium.
Abstract
BACKGROUND AND AIMS: Patients with longstanding ulcerative colitis (UC) are at increased risk of developing colorectal neoplasia. Chromoendoscopy (CE) increases detection of lesions, and Kudo pit pattern classification I and II have been suggested to be predictive of benign polyps in UC. Little is known on the use of this classification in nonmagnified high-definition (HD) (virtual) CE and narrow-band Imaging (NBI) or on the interobserver agreement. The aim of this pilot study was to assess the diagnostic accuracy and the interobserver agreement of the Kudo pit pattern classification in UC patients undergoing surveillance with methylene blue CE or NBI in a multicenter study. METHODS: Fifty images of lesions identified in 27 UC patients (13 neoplastic) either with classical CE (methylene blue .1%; n = 24) or NBI (n = 26) were selected by an independent investigator. Images were selected from a randomized controlled trial to compare CE and NBI. All nonmagnified images were obtained with a processor and mounted in a PowerPoint file in a standardized way (same size; black background). Ten endoscopists with extensive experience in NBI/CE were asked to assess the lesions for the predominant Kudo pit pattern (I, II, IIIL, IIIS, IV, and V) to indicate if they believed the lesion was neoplastic and how confident they were about the diagnosis. Histology was used as the criterion standard. RESULTS: Median sensitivity, specificity, negative predictive value, and positive predictive value for diagnosing neoplasia based on the presence of pit pattern other than I or II was 77%, 68%, 88%, and 46%, respectively. Diagnostic accuracy was significantly higher when a diagnosis was made with a high level of confidence (77% vs 21%, P < .001). The overall interobserver agreement for any pit pattern was only fair (κ = .282), with CE being significantly better than NBI (.322 vs .224, P < .001). From a clinical viewpoint the difference between neoplastic and non-neoplastic lesions is important. The agreement for differentiation between non-neoplastic patterns (I, II) and neoplastic patterns (IIIL, IIIS, IV, or V) was moderate (κ = .587) and even significantly better for NBI in comparison with CE (κ = .653 vs .495, P < .001). CONCLUSIONS: Differentiation between non-neoplastic and neoplastic pit patterns in UC lesions shows a moderate to substantial agreement among expert endoscopists. The agreement for differentiating neoplastic from non-neoplastic lesions is significantly better for NBI in comparison with HD CE. The assessment of pit pattern I or II with nonmagnified HD CE or NBI has a high negative predictive value to rule out neoplasia. (Clinical trial registration number: NCT01882205.).
BACKGROUND AND AIMS: Patients with longstanding ulcerative colitis (UC) are at increased risk of developing colorectal neoplasia. Chromoendoscopy (CE) increases detection of lesions, and Kudo pit pattern classification I and II have been suggested to be predictive of benign polyps in UC. Little is known on the use of this classification in nonmagnified high-definition (HD) (virtual) CE and narrow-band Imaging (NBI) or on the interobserver agreement. The aim of this pilot study was to assess the diagnostic accuracy and the interobserver agreement of the Kudo pit pattern classification in UC patients undergoing surveillance with methylene blue CE or NBI in a multicenter study. METHODS: Fifty images of lesions identified in 27 UC patients (13 neoplastic) either with classical CE (methylene blue .1%; n = 24) or NBI (n = 26) were selected by an independent investigator. Images were selected from a randomized controlled trial to compare CE and NBI. All nonmagnified images were obtained with a processor and mounted in a PowerPoint file in a standardized way (same size; black background). Ten endoscopists with extensive experience in NBI/CE were asked to assess the lesions for the predominant Kudo pit pattern (I, II, IIIL, IIIS, IV, and V) to indicate if they believed the lesion was neoplastic and how confident they were about the diagnosis. Histology was used as the criterion standard. RESULTS: Median sensitivity, specificity, negative predictive value, and positive predictive value for diagnosing neoplasia based on the presence of pit pattern other than I or II was 77%, 68%, 88%, and 46%, respectively. Diagnostic accuracy was significantly higher when a diagnosis was made with a high level of confidence (77% vs 21%, P < .001). The overall interobserver agreement for any pit pattern was only fair (κ = .282), with CE being significantly better than NBI (.322 vs .224, P < .001). From a clinical viewpoint the difference between neoplastic and non-neoplastic lesions is important. The agreement for differentiation between non-neoplastic patterns (I, II) and neoplastic patterns (IIIL, IIIS, IV, or V) was moderate (κ = .587) and even significantly better for NBI in comparison with CE (κ = .653 vs .495, P < .001). CONCLUSIONS: Differentiation between non-neoplastic and neoplastic pit patterns in UC lesions shows a moderate to substantial agreement among expert endoscopists. The agreement for differentiating neoplastic from non-neoplastic lesions is significantly better for NBI in comparison with HD CE. The assessment of pit pattern I or II with nonmagnified HD CE or NBI has a high negative predictive value to rule out neoplasia. (Clinical trial registration number: NCT01882205.).