Primary, this study aims to develop and validate a computer-aided diagnosis (CADx) system for the characterization of colorectal polyps.

Second, this study evaluates the effect of using a clinical classification model Blue Light Imaging Adenoma Serrated International (BASIC) on the diagnostic accuracy of the optical diagnosis of colorectal polyps compared to intuitive optical diagnosis for both expert endoscopists and novices.

Optical diagnosis of colorectal polyps, the in-vivo characterization of the histology by endoscopists, is of increasing interest for clinical endoscopy practice. Recent studies have shown that thresholds for optical diagnosis are met in highly selected groups of expert endoscopists, but the same is not true in community endoscopy practices. In order to improve optical diagnosis, imaging enhancement techniques and the use of artificial intelligence are proposed.

This observational study developes a computer-aided diagnosis (CADx) system to differentiate between benign and (pre-)malignant CRPs, using state-of-the-art machine learning methods and deep learning architectures. For the development, HDWL and BLI images are used. The CADx is trained using histology as gold standard. The CADx is externally validated using on a set of 60 colorectal polyps. This study will evaluate if the optical diagnosis of colorectal polyps can be improved with the aid of CADx.

In addition, both expert endoscopists and novices optically diagnose the colorectal polyps. In the first, pre-training phase, endoscopists optically diagnose colorectal polyps based on intuition. Afterwards, in the post-training phase, the same set of colorectal polyps is optically diagnosed based on a clinical classification system; BLI Adenoma Serrated International Classification (BASIC). This study will evaluate if the optical diagnosis of colorectal polyps can be improved with the aid of BASIC in both expert and non-expert hands.

Inclusion Criteria:

• Patients with at least one colorectal polyp found and resected during colonoscopy in regular care;
• Availability of at least one high definition white light image and one Blue Light Imaging (BLI) image of the colorectal polyp;
• Overall high quality of the colorectal polyp image;
• Availability of the histological results of the colorectal polyp;
• Minimal age of 18 years old.

Exclusion Criteria:

• Objection to participate in medical scientific research, reported in the medical file;
• Endoscopic instruments visible at the colorectal polyp image;
• More than one polyp visible at the colorectal polyp image.

Patients who had a colonoscopy in the Catharina hospital Eindhoven between January 2017 and December 2018 in the context of the regular bowel cancer screening program, in the context of complaints or in the context of the follow-up of previously diagnosed bowel diseases.

At this moment, there is no plan to share individual participant data.