title: Simultaneous fingerprint and high-wavenumber fiber-optic Raman spectroscopy enhances real-time in vivo diagnosis of adenomatous polyps during colonoscopy.
abstract: Colorectal cancer can be prevented if detected early (e.g., precancerous polyps-adenoma). Endoscopic differential diagnosis of hyperplastic polyps (that have little or no risk of malignant transformation) and adenomas (that have prominent malignant latency) remains an unambiguous clinical challenge. Raman spectroscopy is an optical vibrational technique capable of probing biomolecular changes of tissue associated with neoplastic transformation. This work aims to apply a fiber-optic simultaneous fingerprint (FP) and high wavenumber (HW) Raman spectroscopy technique for real-time in vivo assessment of adenomatous polyps during clinical colonoscopy. We have developed a fiber-optic Raman endoscopic technique capable of simultaneously acquiring both the FP (i.e., 800-1800 cm(-1)) and HW (i.e., 2800-3600 cm(-1)) Raman spectra from colorectal tissue subsurface (<200 µm) for real-time assessment of colorectal carcinogenesis. In vivo FP/HW Raman spectra were acquired from 50 patients with 17 colorectal polyps during clinical colonoscopy. Prominent Raman spectral differences (p < 0.001) were found between hyperplastic (n = 118 spectra), adenoma (n = 184 spectra) that could be attributed to changes in inter- and intra-cellular proteins, lipids, DNA and water structures and conformations. Simultaneous FP/HW Raman endoscopy provides a diagnostic sensitivity of 90.9% and specificity of 83.3% for differentiating adenoma from hyperplastic polyps, which is superior to either the FP or HW Raman technique alone. This study shows that simultaneous FP/HW Raman spectroscopy technique has the potential to be a clinically powerful tool for improving early diagnosis of adenomatous polyps in vivo during colonoscopic examination.
authors: Optical Bioimaging Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore.
authors: Mads Sylvest
authors: MS
authors: Bergholt
authors: Optical Bioimaging Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore.
authors: Kan
authors: K
authors: Lin
authors: Optical Bioimaging Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore.
authors: Jianfeng
authors: J
authors: Wang
authors: Optical Bioimaging Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore.
authors: Wei
authors: W
authors: Zheng
authors: Institute of Digestive Disease, Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, 361004, China.
authors: Hongzhi
authors: H
authors: Xu
authors: Institute of Digestive Disease, Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, 361004, China.
authors: Qingwen
authors: Q
authors: Huang
authors: Institute of Digestive Disease, Department of Gastroenterology, Zhongshan Hospital affiliated to Xiamen University, Xiamen, 361004, China.
authors: Jian-Lin
authors: JL
authors: Ren
authors: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, 119260, Singapore.
authors: Khek Yu
authors: KY
authors: Ho
authors: Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, 119074, Singapore.
authors: Ming
authors: M
authors: Teh
authors: Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, 119074, Singapore.
authors: Supriya
authors: S
authors: Srivastava
authors: Department of Pathology, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, 119074, Singapore.
authors: Benjamin
authors: B
authors: Wong
authors: Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, 119260, Singapore.
authors: Khay Guan
authors: KG
authors: Yeoh
authors: Optical Bioimaging Laboratory, Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore. biehzw@nus.edu.sg.
authors: Zhiwei
authors: Z
authors: Huang
mesh_terms: D018256:Adenomatous Polyps / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003113:Colonoscopy / Q000379:methods*; D015179:Colorectal Neoplasms / Q000175:diagnosis; D005260:Female; D005336:Fiber Optic Technology / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013997:Time Factors; D055815:Young Adult
keywords: Raman spectroscopy; adenomatous polyp; colon; colonoscopy; in vivo optical diagnosis