124 The Polycomb Complex PRC2 Regulates the Intestinal Stem Cell Niche and Maturation of the Enterocytes

Introduction: Bowel preparation is likely the most significant reason for low participation in screening colonoscopy, while poor preparation impairs adenoma detection .A CRC screening method that would generate structural data of the colon, without cathartic cleansing or diet restrictions, would offer an attractive alternative for many patients from the target population that are not willing to undergo colonoscopy.Aims & Methods: Aims: To evaluate the safety and correlation between capsule vs. colonoscopic clinical findings.Device: The capsule is similar in dimensions to other approved capsules.Novel ultra-low dose X-ray based imaging technology generates high-resolution 3-dimensional (3D) imagery of the colon without bowel preparation.The capsule is activated and scans the inner surface only when the capsule it is propelled within the colon.Methods: Capsules were swallowed by 51 volunteers aged 41-70 and tracked during the entire passage of the capsule through the alimentary tract using radio frequency telemetry and a capsule localization system (CPS).The system performed scans upon detecting effective capsule motion in the colon and transmitted imaging data to an external recorder unit attached to patients' lower back.Combined data from colon scans and the CPS system were used to reconstruct 3D colon segments in non-prepped colons.Total transit time and total X-ray exposure were calculated to assess the safety profile of the capsule in human subjects.Results: The volunteers were exposed to an ultra-low total radiation dose 0.03 ± 0.0007 mSv (equivalent to 1 chest x-ray) for the entire procedure.The capsule detected polyps of different size, shape and location in the colon.Polyps were considered "same position" compared to colonocopy finding if they were detected in the same colon segment.Figure 1 shows such correlation.Polyps were considered "same morphology" if they presented similar features (see Figure 2).Average total transit time was 73.2 ± 45.4 hours.There were no reports of capsule malfunction or damage which might have compromised the participants' safety.Conclusion: Safety evaluation of a novel, preparation-free, X-ray imaging capsule and correlation of clinical findings to colonoscopy has been performed.Quantitative ultra-low dose X-ray imaging and detection of polyps of different sizes and polyp types was achieved in the colon of human subjects.Further efficacy validation of this X-ray based CRC screening technology will be performed in multicenter studies.