This study is a clinical validation of PolyDeep, a computer-aided polyp detection (CADe) and characterization (CADx) system. PolyDeep Advance 2 is a multicentric randomized clinical trial with a tandem colonoscopy design. The hypothesis of this study is that Polydeep assisted colonoscopy will reduce the number of missed adenomas in the first withdrawal.

Colorectal cancer (CRC) is the most frequently cancer in western world. A fundamental tool for detection and prevention is the colonoscopy. The detection and endoscopic resection of colorectal polyps, the precursor lesion of CRC, can reduce CRC incidence and mortality. Adenoma detection rate is the most used endoscopic quality indicator. The improvement of this indicator is related to the reduction of postcolonoscopy CRC incidence and mortality.

Colorectal polyp diagnosis is based on endoscopic resection and histological analysis. An accurate optical diagnosis could avoid histological lesion of smaller lesions, reducing the costs associated with histological diagnosis. The NICE (NBI International Colorectal Endoscopic) Classification has proposed the use of high definition endoscopes that have Narrow Band Imaging. However, NICE must be used by endoscopists who are sufficiently prepared and who have overcome the learning curve. Therefore, optical histology diagnosis with high accuracy independently of the center and the endoscopist is necessary.

Computer Aid Diagnosis (CAD) systems based on Artificial Intelligence are experiencing exponential development in the field of medical image analysis. The development of the CAD system is based on the creation of large databases of endoscopic images and/or videos, on the training, development and validation of diagnostic algorithms in such databases and, finally, on prospective clinical validation in patients undergoing colonoscopy. The goal of CAD systems in colonoscopy is double. First, it aims to increase the detection of polyps (CADe) in general, and of adenomas and serrated lesions in particular. The second objective is to characterize (CADx) the histology of detected lesion.

PolyDeep CAD is a functional prototype. It is capable of detecting, locating and classifying colorectal polyps. In vivo validation data shows that PolyDeep has high diagnostic accuracy for polyp identification and that this accuracy can be accommodated This clinical trial is part of the clinical validation of PolyDeep. We will perform a randomized clinical trial with a tandem colonoscopy design with adenoma miss rate as the main objective.

Inclusion Criteria:

• First diagnostic colonoscopy performed after a positive fecal immunochemical test performed within the CRC screening program.
• Surveillance after colorectal adenomas resection.
• Authorization after reading the information sheet and singing the informed consent.

Exclusion Criteria:

• Incomplete colonoscopy without cecal intubation.
• Colonoscopies with insufficient intestinal cleansing (Boston Bowel Preparation Scale <6 or <2 in any of the evaluated segments).
• Detected lesions without histological diagnosis.
• Previous CRC.
• Previous colonic resection.
• CRC associated hereditary syndrome.
• Serrated polyposis syndrome.