title: Differentiation of healthy and malignant tissue in colon cancer patients using optical spectroscopy: A tool for image-guided surgery.
abstract: BACKGROUND
  Surgery for colorectal cancer aims for complete tumor resection. Optical-based techniques can identify tumor and surrounding tissue through the tissue specific optical properties, absorption and scattering, which are both influenced by the biochemical and morphological composition of the tissue.
  
  
  OBJECTIVE
  To evaluate the feasibility of dual-modality Diffuse Reflectance Spectroscopy-Fluorescence Spectroscopy (DRS-FS) for discrimination between healthy and malignant tissue in colorectal surgery.
  
  
  METHODS
  Surgical specimens from colorectal cancer patients were measured immediately after resection using a fiber-optic needle capable of dual-modality DRS-FS. Model-based analyses were used to derive scattering and absorption coefficients and intrinsic fluorescence. Volume fractions of chromophores were estimated. Furthermore, optical data were recorded along a trajectory from healthy tissue towards tumor.
  
  
  RESULTS
  Spectral characteristics were identified in 1,273 measured spectra from 21 specimens. Combined DRS and FS discriminated tumor from surrounding tissue with a sensitivity of 95% and a specificity of 88%. Significant spectral changes were seen along the trajectory from healthy tissue to tumor.
  
  
  CONCLUSIONS
  This study demonstrates that dual-modality DRS-FS can identify colorectal cancer from surrounding healthy tissue. The quantification of comprehensible parameters allows robust classification and facilitates extrapolation towards the clinical setting. The technique, here demonstrated in a needle like probe, can be incorporated into surgical tools for optically guided surgery in the near future. Lasers Surg. Med. 47:559-565, 2015. © 2015 Wiley Periodicals, Inc.
authors.affiliation: Department of Surgery, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands.
authors.forename: G C
authors.initials: GC
authors.lastname: Langhout
authors.affiliation: Department of Surgery, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands.
authors.forename: J W
authors.initials: JW
authors.lastname: Spliethoff
authors.affiliation: Department of Surgery, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands.
authors.forename: S J
authors.initials: SJ
authors.lastname: Schmitz
authors.affiliation: Department of Surgery, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands.
authors.forename: A G J
authors.initials: AGJ
authors.lastname: Aalbers
authors.affiliation: Department of Pathology, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands.
authors.forename: M-L F
authors.initials: MF
authors.lastname: van Velthuysen
authors.affiliation: Department of Minimally Invasive Healthcare, Philips Research, Eindhoven, High Tech Campus 34, 5656 AE Eindhoven, the Netherlands.
authors.forename: B H W
authors.initials: BHW
authors.lastname: Hendriks
authors.affiliation: Department of Surgery, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands.|Nanobiophysics Group, MIRA Institute, University of Twente, P.O. Box 217, 7500 AE Enschede, the Netherlands.
authors.forename: T J M
authors.initials: TJM
authors.lastname: Ruers
authors.affiliation: Department of Surgery, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Plesmanlaan 121, 1066 CX, Amsterdam, the Netherlands.
authors.forename: K F D
authors.initials: KFD
authors.lastname: Kuhlmann
keywords: colorectal cancer; diffuse reflectance spectroscopy; fluorescence; image guided surgery; optical spectroscopy; surgery