Reliability and accuracy of blue light imaging for staging of intestinal metaplasia in the stomach

Abstract

Background and aims: An endoscopic grading system (EGGIM) using narrow-band-imaging (NBI) has shown to accurately identify patients with extensive gastric intestinal metaplasia (GIM). However, description with alternative systems such as blue-light-imaging (BLI) is limited. The aim of this study is to determine the reliability and accuracy of BLI-bright regarding diagnosis and staging of GIM.

Methods: Reliability of WLE (white-light-endoscopy) and BLI among 6 observers was assessed using a standard classification based on endoscopic images. Afterward, 37 patients were submitted to gastroscopy using FujifilmEG-760Z and endoscopists had to determine EGGIM score using BLI-bright and to perform gastric biopsies for operative-link-of-gastric-intestinal-metaplasia (OLGIM) calculation. BLI-bright accuracy was determined by comparing results with prior EGGIM scores with NBI and current OLGIM.

Results: Compared with WLE, the interobserver reliability between observers was substantially better with BLI (Weighted Kappa: 0.8 vs 0.41). There was an 84% agreement between BLI and NBI assessing EGGIM intervals (EGGIM 0-4vs5-10). The area under the ROC curve was 0.90 (95%CI: 0.79–1.0) using the cut-off of EGGIM > 4 to determine advanced GIM, with a sensitivity of 100% (95%CI: 88–100%).

Discussion: BLI-bright is reliable for the diagnosis of gastric intestinal metaplasia and agrees significantly with NBI evaluation. Preliminary data suggests high sensitivity for identifying patients with increased risk of gastric cancer.

Keywords:

• Gastric intestinal metaplasia
• operative link of gastric intestinal metaplasia (OLGIM)
• narrow band imaging (NBI)
• blue light imaging (BLI)
• endoscopic grading of gastric intestinal metaplasia (EGGIM)

Disclosure statement

No potential conflict of interest was reported by the authors.