title: Ultrastructural alterations in field carcinogenesis measured by enhanced backscattering spectroscopy.
abstract: Optical characterization of biological tissue in field carcinogenesis offers a method with which to study the mechanisms behind early cancer development and the potential to perform clinical diagnosis. Previously, low-coherence enhanced backscattering spectroscopy (LEBS) has demonstrated the ability to discriminate between normal and diseased organs based on measurements of histologically normal-appearing tissue in the field of colorectal (CRC) and pancreatic (PC) cancers. Here, we implement the more comprehensive enhanced backscattering (EBS) spectroscopy to better understand the structural and optical changes which lead to the previous findings. EBS provides high-resolution measurement of the spatial reflectance profile P(rs) between 30 microns and 2.7 mm, where information about nanoscale mass density fluctuations in the mucosa can be quantified. A demonstration of the length-scales at which P(rs) is optimally altered in CRC and PC field carcinogenesis is given and subsequently these changes are related to the tissue's structural composition. Three main conclusions are made. First, the most significant changes in P(rs) occur at short length-scales corresponding to the superficial mucosal layer. Second, these changes are predominantly attributable to a reduction in the presence of subdiffractional structures. Third, similar trends are seen for both cancer types, suggesting a common progression of structural alterations in each.
authors.affiliation: Northwestern University, Department of Biomedical Engineering, Tech E310, 2145 Sheridan Road, Evanston, Illinois 60208.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Radosevich
authors.forename: Nikhil N
authors.initials: NN
authors.lastname: Mutyal
authors.forename: Ji
authors.initials: J
authors.lastname: Yi
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Stypula-Cyrus
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Rogers
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Goldberg
authors.forename: Laura K
authors.initials: LK
authors.lastname: Bianchi
authors.forename: Shailesh
authors.initials: S
authors.lastname: Bajaj
authors.forename: Hemant K
authors.initials: HK
authors.lastname: Roy
authors.forename: Vadim
authors.initials: V
authors.lastname: Backman
mesh_terms: D001706:Biopsy; D063646:Carcinogenesis / Q000473:pathology*; D015179:Colorectal Neoplasms / Q000648:ultrastructure*; D003198:Computer Simulation; D006801:Humans; D008027:Light; D009010:Monte Carlo Method; D010190:Pancreatic Neoplasms / Q000648:ultrastructure*; D012542:Scattering, Radiation; D012815:Signal Processing, Computer-Assisted; D013057:Spectrum Analysis / Q000379:methods*