Expert Assessment on Volumetric Laser Endomicroscopy Full-Scans in Barrett's Esophagus Patients With or Without High-Grade Dysplasia or Early Cancer.

BACKGROUND: Volumetric laser endomicroscopy (VLE) allows for near-microscopic imaging of the superficial esophageal wall, and may improve detection of early neoplasia in Barrett's esophagus (BE). Interpretation of a 6-cm long, circumferential VLE "full-scan", may however be challenging for endoscopists.

AIM: To evaluate accuracy of VLE-experts for correctly diagnosing VLE full-scans of early neoplasia and non-dysplastic (ND)BE.

METHODS: Twenty-nine VLE full-scan videos (15 neoplastic and 14 NDBE) were randomly evaluated by twelve VLE-experts using a web-based module. Experts were blinded to endoscopic BE-images and histology. Fifteen neoplastic cases contained a subtle endoscopically-visible lesion which upon endoscopic resection showed high-grade dysplasia or cancer. NDBE cases had no visible lesions and absence of dysplasia in all biopsies. VLE-videos were first scored as "neoplastic" or "NDBE". If neoplastic, assessors located the area most suspicious for neoplasia. Primary outcomes: performance of VLE experts to differentiate between non-dysplastic and neoplastic full scan videos, calculated by accuracy, sensitivity and specificity.

SECONDARY OUTCOMES: correct localization of neoplasia, inter-observer agreement and level of confidence.

RESULTS: VLE-experts correctly labelled 73% (95%CI, 67-79) of the neoplastic VLE-videos. In 54% (range, 27-66) both neoplastic diagnosis and lesion location was correct. NDBE videos were consistent with endoscopic biopsy in 52% (95%CI, 46-57). Inter-observer agreement was fair (kappa=0.28). High level of confidence was associated with a higher rate of correct neoplastic diagnosis (81%) and lesion localization (73%).

CONCLUSIONS: Identification of subtle neoplastic lesions in VLE full-scans by experts was disappointing. Future studies should focus on improving methodologies for reviewing full-scans, development of refined VLE-criteria for neoplasia, and computer-aided diagnosis in VLE-scans.