Optical Diagnosis Versus Laser Measurement of Polyps' Size During Colonoscopy and Implications for Surveillance

Recent updates of the guidelines on polyp surveillance of the American Society of Gastrointestinal Endoscopy (ASGE) and European Society of Gastrointestinal Endoscopy (ESGE) increasingly focus on size of polyps as an important indicator of malignant transformation to colorectal cancer (CRC). However, the interobserver variability in polyp size assessment between optical diagnosis of endoscopists and pathologists is considerable. This may lead to incorrect surveillance intervals in patients at risk for developing colorectal cancer, which may increase the risk of post-colonoscopy CRC (PCCRC). This study aims to assess the precision of a new laser-based measurement system (AccuMeasure, VTM Technologies Ltd.) for polyps during colonoscopy.

Objective: The main objective is to compare the precision of polyp size measurement by AccuMeasure to biopsy forceps assisted measurement. Secondary objectives are to assess: Time needed for measurement and learning curve, endoscopists advised surveillance intervals based on both measurement methods, and safety. Study design: Multicenter, randomized, parallel group, endoscopist blinded study, including the measurement of 138 polyps during standard colonoscopy. With a polyp detection rate of approximately 40%1, this results in up to 345 patients/colonoscopies to be included. Enrollment will conclude once 138 polyps are included in the study. Study population: All adult patients with screening or surveillance colonoscopies will be asked for informed consent. Polyps smaller than 25mm found during colonoscopy are considered eligible for inclusion. Up to 3 polyps per patient can be included in this study. Intervention: Optical assessment will be performed upon identification of the polyp. Then, measurement with AccuMeasure and biopsy forceps will be performed in a randomized order. The endoscopist will remain blinded to the AccuMeasure measurement outcomes, to avoid a learning effect that could influence subsequent measurements.