External validation of a classification for methylene blue magnification chromoendoscopy in premalignant gastric lesions

Abstract

Background: Conventional endoscopy has low sensitivity, specificity, and interobserver agreement for the diagnosis of gastric atrophy, intestinal metaplasia, and dysplasia. Magnification chromoendoscopy (ME) may optimize the evaluation of premalignant gastric lesions.Objective and Design: As part of a multicenter trial, we aimed at validating a previously proposed classification for gastric methylene blue ME at a different center.Setting, Patients, and Interventions: A sample of patients (n Z 42) with previously diagnosed chronic atrophic gastritis with or without intestinal metaplasia underwent ME (Pentax EG-3430Z) with 1% methylene blue by 2 endoscopists. Main Outcome Measurements:A simplified version of a previously published ME classification (group I, group II [further divided into subgroups IIE and IIF], and group III) was used for macroscopic lesions (n Z 203) with Sydney-Houston and Vienna classifications being used for histologic analysis (n Z 479 biopsy specimens). Conclusions: This classification for methylene blue ME was highly reproducible and valid for the diagnosis of premalignant gastric lesions when used in a center different from that involved in its conception. Despite requiring an unconventional endoscope and a longer procedure, these results could reinforce ME as a valuable technique in the surveillance of patients at risk for gastric cancer. (Gastrointest Endosc 2008;67:1011-8.) Gastric cancer has a high incidence worldwide and is the second most lethal neoplasm of the digestive tract. Moreover, in Portugal it ranks second in incidence of all neoplastic diseases.

Magnifying Endoscopy and Chromoendoscopy in Upper Gastrointestinal Tract - Clinical Applications

“…This prescribes a considerable effort in order to evaluate the risk of the patient for the development of gastric cancer. Magnification chromoendoscopy may optimize the evaluation of premalignant gastric lesions (Areia et al, 2008). Topographic mapping for the detection of extensive intestinal metaplasia or more advanced lesions such as dysplasia or carcinoma should be consider when evaluating the patient's risk (Correa et al, 2010).…”

Near‐infrared Raman spectroscopy for gastric precancer diagnosis

“…[4] However, early detection of gastric dysplasia renders a great challenge to the endoscopists as these flat lesions are usually lack of obvious gross morphological changes to be visualized under conventional white-light endoscopy. [5] In the past decade, Raman spectroscopy, which measures inelastic light scattering processes and is capable of providing specific spectroscopic fingerprints of molecular compositions and structures of biological tissues, has been comprehensively investigated for precancer and cancer diagnosis and evaluation. [6 -22] Under near-infrared (NIR) laser light excitation, the resulting NIR Raman spectroscopy holds significant advantages in that water exhibits very low absorption at the working wavelength range, and tissues exhibit far less autofluorescence.…”

Towards more adequate colour histograms for in-body images

“…Dinis-Ribeiro et al [9] showed that it was possible to effectively diagnose certain gastric lesions (namely extension of intestinal metaplasia in the gastric mucosa) and adequately predict neoplasia occurrence using this technology. Dinis-Ribeiro developed an original classification for gastric mucosa, recently externally validated [10], dividing images into 3 groups based on their colour and texture features, which were proven to be robust in intra-observer and inter-observer evaluation. A future objective of our research is to automate this classification, based on the promising results of the study presented here.…”