Accuracy of real-time vs. blinded offline diagnosis of neoplastic colorectal polyps using probe-based confocal laser endomicroscopy: a pilot study.

BACKGROUND AND STUDY AIMS

Probe-based confocal laser endomicroscopy (pCLE) is a new imaging modality that enables histological examination of gastrointestinal mucosa during endoscopic procedures. Most studies have evaluated offline interpretation of pCLE images. In clinical practice, real-time interpretation is necessary to assist decision-making during the procedure. The aim of this pilot study was to compare the accuracy of real-time pCLE diagnosis made during the procedure with that of blinded offline interpretation to provide accuracy estimates that will aid the planning of future studies.

PATIENTS AND METHODS

pCLE was performed in patients undergoing screening and surveillance colonoscopy. Once a polyp had been identified, one endoscopist analyzed pCLE images during the procedure and made a provisional "real-time" diagnosis. Saved video recordings were de-identified, randomized, and reviewed "offline" 1 month later by the same endoscopist, who was blinded to the original diagnoses.

RESULTS

Images from a total of 154 polyps were recorded (80 neoplastic, 74 non-neoplastic). The overall accuracy of real-time pCLE diagnosis (accuracy 79%, sensitivity 81%, specificity 76%) and offline pCLE diagnosis (83%, 88%, and 77%, respectively) for all 154 polyps were similar. Among polyps < 10 mm in size, the accuracy of real-time interpretation was significantly lower (accuracy 78%, sensitivity 71%, specificity 83%) than that of offline pCLE interpretation (81%, 86%, 78%, respectively). For polyps ≥ 10 mm, the accuracy of pCLE diagnosis in real-time was better (accuracy 85%, sensitivity 90%, specificity 75%) than offline pCLE diagnosis (81%, 97%, and 50%, respectively).

CONCLUSIONS

These results suggest that real-time and offline interpretations of pCLE images are moderately accurate. Real-time interpretation is slightly less accurate than offline diagnosis, but overall both are comparable. Additionally, there was contrasting accuracy between the two methods for small and large polyps.