Endoscopic Optical Coherence Tomography for Screening and Diagnosis of Colorectal Precancerous and Malignant Polyps

Colorectal cancer arises from the mucosal layer of the colon. Current screening is performed by flexible endoscopy, which involves visual inspection of the mucosal lining of the colon and rectum with an optical camera mounted on the endoscope, with abnormal areas being biopsied. This method is somewhat limited in that there are no readily available surface pattern or morphological classification systems with adequate sensitivity or specificity to evaluate extent of submucosal invasion (deep, superficial, or none). Optical coherence tomography (OCT) using pattern recognition is a high-resolution imaging modality. There is currently an unmet need to predict depth of invasion for colonic tumors to decide on applicability of endoscopic (endoscopic submucosal dissection or endoscopic mucosal resection) vs. surgical therapy. The investigators' hypothesis is that OCT will have a higher diagnostic accuracy for determining depth of submucosal invasion compared to existing modalities. The investigators will first aim to assess the procedural feasibility and safety of using an OCT probe during routine colonoscopy with an early feasibility study. This study will identify appropriate modifications to the device and help with development of subsequent clinical study protocols. The eventual goal is to assess the diagnostic accuracy of OCT imaging for predicting depth of invasion of colonic tumors.