New classification for probe-based confocal laser endomicroscopy in the colon

Area of Science:

• Gastroenterology
• Medical Imaging
• Endoscopy

Background:

• Probe-based confocal laser endomicroscopy (pCLE) offers in vivo histology during colonoscopy for real-time diagnosis.
• A novel pCLE classification system for colonic use was developed by expert consensus.
• Assessing the reliability of this new classification is crucial for its clinical adoption.

Purpose of the Study:

• To evaluate the interobserver agreement of a new pCLE classification system in the colon.
• To determine the accuracy of the new pCLE classification in differentiating neoplastic from non-neoplastic colonic lesions.
• To assess the impact of consensus among observers on diagnostic accuracy.

Main Methods:

• Prospective pCLE investigation of eligible patients.
• Development of a new classification based on 13 pCLE video sequences (3 vessel, 7 crypt categories).
• Blinded review of 102 pCLE video sequences by five observers using the new classification, with histopathology as the reference standard.

Main Results:

• Interobserver agreement for vessel and crypt architecture was 'fair' (κ=0.29, κ=0.27).
• Agreement improved to 'moderate' (κ=0.56) when classifying as neoplasia vs. non-neoplasia.
• Overall sensitivity and specificity for neoplasia prediction were 66% and 83%; agreement among all observers yielded 80% sensitivity and 95% specificity.

Conclusions:

• The new pCLE classification demonstrated moderate interobserver agreement for differentiating colonic neoplasia.
• The overall accuracy of 81% for neoplasia prediction is acceptable.
• Excellent accuracy (94%) was achieved when all observers reached consensus, highlighting the need for classification refinement and validation.