Endoscopy 2012; 44(03): 236-246
DOI: 10.1055/s-0031-1291537
Original article
© Georg Thieme Verlag KG Stuttgart · New York

A multicenter validation of an endoscopic classification with narrow band imaging for gastric precancerous and cancerous lesions

P. Pimentel-Nunes*
1   Department of Gastroenterology, Portuguese Oncology Institute of Porto, Porto, Portugal
2   Department of Physiology, Cardiovascular Research and Development Unit, Porto Faculty of Medicine, Porto University, Porto, Portugal
,
M. Dinis-Ribeiro*
1   Department of Gastroenterology, Portuguese Oncology Institute of Porto, Porto, Portugal
3   CINTESIS/Biostatistics and Medical Informatics, Faculty of Medicine, Porto University, Porto, Portugal
,
J. B. Soares
2   Department of Physiology, Cardiovascular Research and Development Unit, Porto Faculty of Medicine, Porto University, Porto, Portugal
4   Department of Gastroenterology, Hospital de Braga, Braga, Portugal
,
R. Marcos-Pinto
5   Department of Gastroenterology, Centro Hospitalar do Porto, Porto, Portugal
,
C. Santos
3   CINTESIS/Biostatistics and Medical Informatics, Faculty of Medicine, Porto University, Porto, Portugal
,
C. Rolanda
4   Department of Gastroenterology, Hospital de Braga, Braga, Portugal
6   Surgical Sciences Research Domain, Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal
,
R. P. Bastos
7   Department of Gastroenterology, Hospital de São João, Porto, Portugal
,
M. Areia
8   Department of Gastroenterology, Portuguese Oncology Institute of Coimbra, Coimbra, Portugal
,
L. Afonso
9   Department of Pathology, Portuguese Oncology Institute of Porto, Porto, Portugal
,
J. Bergman
10   Department of Gastroenterology, Academic Medical Center, Amsterdam, The Netherland
,
P. Sharma
11   Division of Gastroenterology and Hepatology, Veterans Affairs Medical Center, Kansas City, Missouri, USA
,
T. Gotoda
12   Department of Gastroenterology and Hepatology, National Center for Global Health and Medicine, Tokyo, Japan
,
R. Henrique
9   Department of Pathology, Portuguese Oncology Institute of Porto, Porto, Portugal
13   Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal
,
L. Moreira-Dias
1   Department of Gastroenterology, Portuguese Oncology Institute of Porto, Porto, Portugal
› Author Affiliations
Further Information

Publication History

submitted 04 March 2011

accepted after revision 14 October 2011

Publication Date:
31 January 2012 (online)

Background and study aim: The reliability and external validity of narrow band imaging (NBI) in the stomach have not been described consistently. The aim of the current study was to describe and estimate the accuracy and reliability of a simplified classification system for NBI in the diagnosis of gastric lesions.

Methods: Consecutive patients undergoing NBI endoscopy at two reference centers (n = 85, 33 % with dysplasia) were included in two studies. In total, 224 different areas were biopsied and recorded onto video. In the derivation study, previously described NBI features were analyzed in order to develop a simplified classification. In the validation study the accuracy and reliability of this classification were estimated among three groups of endoscopists with different levels of expertise in NBI.

Results: The reliability/accuracy results from the derivation study allowed the creation of a simplified NBI classification. In the validation study, “regular vessels with circular mucosa” (pattern A) was associated with normal histology (accuracy 83 %; 95 % confidence interval [CI] 75 % – 90 %); “tubulo-villous mucosa” (pattern B) was associated with intestinal metaplasia (accuracy 84 %; 95CI 77 % – 91 %; positive likelihood ratio [LR + ] = 4.75); and “irregular vessels and mucosa” (pattern C) was associated with dysplasia (accuracy 95 %; 95CI 90 % – 99 %; LR + = 44.33). The reproducibility of these patterns was high (k = 0.62). “Light-blue crest” was moderately reliable (k = 0.49) but specific (87 %) for intestinal metaplasia. A variable vascular density (additional pattern + ) was the best feature for Helicobacter pylori gastritis (accuracy 70 %; 95CI 59 % – 80 %) but showed only fair reliability (k = 0.38). Non-experienced endoscopists presented lower agreement (k = 0.6 vs. k = 0.75) and accuracy (74 % vs. 86 %) than international experts/experienced endoscopists.

Conclusion: A simplified NBI classification is accurate and reliable for the diagnosis of intestinal metaplasia and dysplasia. The classification should be further assessed and validated on a per-patient assessment of NBI, and by comparing NBI with other imaging technologies.

* The authors contributed equally to this study and should be considered joint first authors.


Fig.e1 is available online: