Learning Curve and Interobserver Agreement of Confocal Laser Endomicroscopy for Detecting Precancerous or Early-Stage Esophageal Squamous Cancer

Abstract

BackgroundConfocal laser endomicroscopy (CLE) can provide in vivo subcellular resolution images of esophageal lesions. However, the learning curve in interpreting CLE images of precancerous or early-stage esophageal squamous cancer is unknown. The goal of this study is to evaluate the diagnostic accuracy and inter-observer agreement for differentiating esophageal lesions in CLE images among experienced and inexperienced observers and to assess the learning curve.MethodAfter a short training, 8 experienced and 14 inexperienced endoscopists evaluated in sequence 4 sets of high-quality CLE images. Their diagnoses were corrected and discussed after each set. For each image, the diagnostic results, confidence in diagnosis, quality and time to evaluate were recorded.ResultsOverall, diagnostic accuracy was greater for the second, third, fourth set of images as compared with the initial set (odds ratio [OR] 2.01, 95% CI 1.22–3.31; 7.95, 3.74–16.87; and 6.45, 3.14–13.27), respectively, with no difference between the third and fourth sets in accuracy (p = 0.67). Previous experience affected the diagnostic accuracy only in the first set of images (OR 3.70, 1.87–7.29, p<0.001). Inter-observer agreement was higher for experienced than inexperienced endoscopists (0.732 vs. 0.666, p<0.01)ConclusionCLE is a promising technology that can be quickly learned after a short training period; previous experience is associated with diagnostic accuracy only at the initial stage of learning.

Interobserver agreement of confocal laser endomicroscopy for detection of head and neck neoplasia

“…Novice observers reached moderate levels of agreement in this study (κ = 0.55) . Another study in detecting precancerous or early‐stage esophageal squamous cancers found overall substantial agreement among experienced and novice users alike . We achieved similar results, with overall substantial agreement being achieved among users of varying experience levels in both our image and video sets after uniform, brief, self‐guided, training describing specific image criteria.…”

“…Talreja et al demonstrated substantial agreement with improved diagnostic accuracy in a follow‐up study that incorporated a standardized classification system and a single teaching session . Liu et al demonstrated a similar quick learning curve when agreement (κ) was significantly higher in the experienced group over the inexperienced group in only the first set of four image sets . Although we did not directly test for learning curve, we believe that we achieved substantial agreement due to pretest training using predefined image classification criteria.…”

“…A number of studies have already shown the utility and diagnostic accuracy of using pCLE in multiple GI diseases spanning the GI tract from Barrett's esophagus to colorectal cancer. 11,16,17 Studies have shown high diagnostic accuracy above 90% in diagnosing Barrett's esophagus and above 95% accuracy in detecting neoplastic changes in colonic mucosa. 17 Likewise, we have successfully shown similar diagnostic accuracy of pCLE for use in the head and neck in our pilot study.…”

Image-enhanced endoscopy technology in the gastrointestinal tract: What is available?

“…In addition to this there is a learning curve required to interpret the images that are vastly different from traditional endoscopic images. One study estimated an average learning curve of 35 cases required to interpret post-procedural CLE images with 93% accuracy [47,48]. Case selection will be key in maximizing outcomes obtained from this modality.…”

miR-449b rs10061133 and miR-4293 rs12220909 polymorphisms are associated with decreased esophageal squamous cell carcinoma in a Chinese population

“…The overall 5-year survival rate is about 15 to 25 %, and the outcome depends on whether it is diagnosed at the early stage [1]. The two most common types of esophageal cancer are esophageal adenocarcinoma (EADC) and esophageal squamous cell carcinoma (ESCC) [2], and the latter is the predominant one in China [3].…”