Original article
Clinical endoscopy
Experienced versus inexperienced confocal endoscopists in the diagnosis of gastric adenocarcinoma and intestinal metaplasia on confocal images

https://doi.org/10.1016/j.gie.2011.01.068Get rights and content

Background

Confocal laser endomicroscopy (CLE) may be used to diagnose gastric cancer and intestinal metaplasia, but the impact of CLE experience on the accuracy of confocal diagnosis of gastric cancer and intestinal metaplasia is not clear.

Objective

To establish the sensitivity, specificity, and intragroup interobserver agreement of CLE image interpretation by 3 experienced (group 1) and 3 inexperienced (group 2) CLE endoscopists for diagnosing gastric intestinal metaplasia (GIM) and adenocarcinoma.

Design

Blinded review of CLE images for the diagnosis of gastric cancer or intestinal metaplasia.

Setting

Tertiary care hospital.

Patients

CLE images obtained ex vivo from gastrectomy specimens with proven gastric cancer and CLE images obtained in vivo from Chinese subjects older than 50 years of age by using matched biopsy specimens as reference standards.

Main Outcome Measurements

Sensitivity, specificity, and intragroup interobserver agreement of CLE image interpretation.

Results

Interpretation of in vivo images by group 1 was associated with higher sensitivity (95.2% vs 61.9%, P = .039) and higher specificity (93.3% vs 62.2%, P < .001) for GIM than interpretation by group 2. The agreement between interpretation by group 1 and histology for GIM was higher than that for group 2 (κ = 0.864 vs 0.217). The sensitivity (93.3% for group 1 vs 86.7% for group 2, P = 1.000) and specificity (87.7% for group 1 vs 80.7% for group 2, P = .344) of interpretation of ex vivo CLE images for the diagnosis of gastric adenocarcinoma was similar for groups 1 and 2.

Limitations

Single-center study.

Conclusions

Experience in CLE was associated with greater accuracy in the diagnosis of intestinal metaplasia.

Section snippets

Equipment

A confocal laser endomicroscope (Pentax, Tokyo, Japan) was used for the study. The instrument enables CLE in addition to standard video endoscopy. Confocal images could be generated simultaneously with endoscopic images. In laser scanning confocal microscopy, focal laser illumination is combined with pinhole limited detection to geometrically reject out-of-focus light. Each resulting image is an optical section representing approximately 1 focal plane within the specimen. The optical slice

Results

Six gastric cancer resection specimens were used for the ex vivo study. The confocal images obtained from the first 3 resection specimens were used for the consensus meetings to determine the diagnostic criteria for gastric cancer. The confocal images from the next 3 resection specimens were used for the image assessment.

Thirty patients were recruited for the in vivo study. The confocal images from the first 10 patients were used in the consensus meetings. The confocal images from the next 20

Discussion

This study suggests that when CLE is used by endoscopists with a specialized interest in confocal imaging, it is an accurate method for the diagnosis of GIM and gastric cancer, and experts with previous CLE experience perform better than nonexperts for the diagnosis of GIM on CLE images. After receiving training in the interpretation of confocal images, although inexperienced CLE endoscopists perform as well as experienced CLE endoscopists in the diagnosis of gastric cancer on CLE images, the

Acknowledgments

We thank Yeo Lei Pheng and Jennie Wong for their assistance.

References (17)

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DISCLOSURE: All authors disclosed no financial relationships relevant to this publication.

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