Detection and characterization of colorectal polyps using high-definition white light and i-Scan: Evidence-based consensus recommendations using a modified Delphi process

Background: i-Scan is an image enhancement modality, which provides enhanced views of mucosal structures and vascular patterns. Methods: A modified Delphi process was used to develop a series of evidence-based statements on the role of high-definition white light (HDWL) and i-Scan for the detection and diagnosis of colorectal neoplasms. Each statement was voted to achieve consensus (i.e. >80% agreement). Results: Seven proposed statements achieved consensus: (1) HDWL is recommended rather than standard definition (SD) for detection and diagnosis of colorectal neoplasms; (2) HDWL colonoscopy with i-Scan improves polyp and adenoma detection rates when compared with SD colonoscopy; (3) HDWL+i-Scan is superior to HDWL alone for the optical diagnosis of colorectal neoplasms; (4) HDWL+i-Scan in expert hands meets American Society for Gastrointestinal Endoscopy (ASGE) in the Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) standards for optical diagnosis of diminutive neoplasms; (5) HDWL+i-Scan in non-expert hands does not meet ASGE PIVI standards for optical diagnosis of diminutive neoplasms; (6) optical diagnosis of polyps with i-Scan has a learning curve and needs systematic training; and (7) the performance of i-Scan for the in vivo diagnosis of colorectal neoplasms is similar to Narrow Band Imaging (NBI) and Fuji Intelligent Chromo Endoscopy (FICE). Conclusions: Seven proposed statements on the use of HDWL and i-Scan for the detection and diagnosis of colorectal neoplasms achieved consensus.