Learning curve and competence for volumetric laser endo-microscopy in Barrett's esophagus using cumulative sum analysis

Background and study aims Little is known about the learning curve for image interpretation in volumetric laser endomicroscopy (VLE) in Barrett's esophagus (BE). The goal of this study was to calculate the learning curve, competence of image interpretation, sensitivity, specificity, and accuracy of VLE among novice users. Methods 31 novice users viewed 96 VLE images electronically at three academic institutions after a brief training session. There were 24 images of each histologic type: normal gastric cardia, normal esophageal squamous epithelium, non-neoplastic BE, and neoplastic BE. The users were asked to identify the correct tissue type and level of confidence. The cumulative summation (CUSUM) technique was used to construct a learning curve. Results 22 (71%) of the physicians achieved VLE interpretation competency during their 96-slide review. Half of the physicians achieved competency at 65 images (95% confidence interval [CI] 45-85). There was a statistically significant association between confidence in diagnosis and selecting the correct histologic tissue type (P < 0.001). The median accuracy for esophageal squamous epithelium, normal gastric cardia, non-neoplastic BE, and neoplastic BE was 96% (95%CI 95%-96%), 95% (95%CI 94% - 96%), 90% (95%CI 88% - 91%), 96% (95%CI 95% - 96%). The overall accuracy was 95% (95%CI 93% - 95%). Conclusion The majority of novice users achieved competence in image interpretation of VLE for BE, using a pre-selected image set, with a favorable learning curve after a brief training session. An electronic review of VLE images, prior to real-time use of VLE, is encouraged.