I-SCAN OPTICAL ENHANCEMENT FOR THE IN VIVO PREDICTION OF DIMINUTIVE COLORECTAL POLYP HISTOLOGY: RESULTS FROM A PROSPECTIVE THREE-PHASED MULTICENTRE TRIAL

Aims:

Recently dye-less chromoendoscopy techniques have been emerging for diminutive colorectal polyp characterization. Herein, we investigated whether the newly introduced I-scan optical enhancement (OE) can accurately predict polyp histology in vivo in real time.

Methods:

In this prospective three-phased study, 84 patients with 230 diminutive colorectal polyps were included. During the first two study phases, five endoscopists assessed whether analysis of polyp colour, surface and vascular pattern under i-scan OE can differentiate in vivo between adenomatous and hyperplastic polyps. Finally, junior and experienced endoscopists (JE, EE, each n = 4) not involved in the prior study phases made a post hoc diagnosis of polyp histology using a static i-scan OE image database. Histopathology was used as a gold-standard in all study phases.

Results:

The overall accuracy of i-scan OE for histology prediction was 90.1% with a sensitivity, specificity, positive (PPV) and negative prediction value (NPV) of 91.4%, 89.8%, 85.9% and 93.9%, respectively. In high confidence predictions, the diagnostic accuracy increased to 93% with sensitivity, specificity, PPV and NPV of 94.1%, 91.4%, 88.8% and 95.5%. Colonoscopy surveillance intervals were predicted correctly in ≥90% of patients. In the post hoc analysis EE predicted polyp histology under i-scan OE with an overall accuracy of 90.6%. After a single training session, JE achieved a comparable diagnostic performance for predicting polyp histology with i-scan OE.

Conclusions:

The histology of diminutive colorectal polyps can be accurately predicted with i-scan OE in vivo in real-time. Furthermore, polyp differentiation with i-scan OE appears to require only a short learning curve.