Non-Invasive Discrimination of Colorectal Adenomas and Non-Neoplastic Polyps with Micro-Optical Coherence Tomography Imaging

As one of the most common cancers and a leading cause of worldwide cancer-related mortality, colorectal cancer (CRC) imposes a huge burden on both patients and social healthcare systems. Currently, although colonoscopy screening has been widely utilized for CRC diagnosis, the commonly adopted “resect and discard” strategy for colorectal diminutive polyps treatment in CRC diagnostic process still suffers from the risk of missing the unrecognized potential malignant lesions, like adenomatous polyps. In this study, we explore and validate the feasibility of micro-optical coherence tomography (μOCT) as an intraoperative imaging tool to perform optical biopsy in gastroenterology, and thus, to improve the diagnostic accuracy of colorectal lesions. Specifically, a lab-customized μOCT system that achieves a spatial resolution of ~2.0 μm was built first, and then, was applied to acquire both cross-sectional and 3D images of the fresh tissue samples obtained from patients with colorectal polyps or colorectal cancer and just received endoscopic therapy or laparoscopic surgery. Finally, those acquired images are compared to their corresponding HE sections for discrimination of colorectal adenomas and non-neoplastic polyps. A new diagnostic strategy has also been established to determine the diagnosis sensitivity, specificity and accuracy for using μOCT to differentiate between benign polyps and adenomas. Results show that the μOCT system is capable of clearly illustrating the cellular/sub-cellular microstructure differences between colorectal adenomas and non-neoplastic polyps with the cross-sectional and en face images. While with the new diagnostic criteria applied for all 58 cases of polyps, the diagnosis accuracy, sensitivity and specificity reach up to 94.83%, 96.88% and 92.31% with a 95% confidence interval of (85.30%−98.79%), (82.89%−99.99%) and (74.74%−98.98%), respectively. Such satisfactory results demonstrate the potential of μOCT as an intraoperative diagnostic imaging tool for endoscopists to perform “optical biopsy”, and thus, make appropriate clinical decisions in clinical practice.