title: Endoscopic Raman spectroscopy enables objective diagnosis of dysplasia in Barrett's esophagus.
abstract: BACKGROUND
  Early detection and targeted endoscopic resection of Barrett's esophagus-associated high-grade dysplasia (HGD) can prevent progression to invasive esophageal malignancy. Raman spectroscopy, a highly sophisticated analytical technique, has been translated into an endoscopic tool to facilitate rapid, objective diagnosis of dysplasia in the esophagus.
  
  
  OBJECTIVE
  To evaluate the ability of endoscopic Raman spectroscopy (ERS) to objectively detect esophageal HGD and adenocarcinoma.
  
  
  METHODS
  A total of 798 one-second spectra were measured from 673 ex vivo esophageal tissue samples, collected from patients with Barrett's esophagus by using a novel endoscopic Raman probe. Spectra were correlated with consensus histopathology. Multivariate analysis was used to evaluate the classification accuracy of ERS ex vivo.
  
  
  METHODS
  Probe measurements were conducted in the laboratory. Tissue specimens were collected from the operating theatre and endoscopy unit.
  
  
  METHODS
  Tissue from 62 patients was included in the study.
  
  
  METHODS
  Endoscopic biopsy/resection or esophagectomy was performed where indicated clinically.
  
  
  METHODS
  Diagnostic performance of ERS for detection of HGD and esophageal adenocarcinoma.
  
  
  RESULTS
  ERS demonstrated a sensitivity of 86% and a specificity of 88% for detecting HGD and adenocarcinoma. The ability to grade dysplasia and differentiate intestinal metaplasia from nonintestinal metaplasia columnar-lined esophagus was also demonstrated. Diagnostic classification was based on objective measurement of the biochemical profile of different tissue types. The potential for combination ERS and narrow-band imaging was also demonstrated.
  
  
  CONCLUSIONS
  Measurements were taken from ex vivo tissue.
  
  
  CONCLUSIONS
  ERS enables rapid, accurate, objective diagnosis of superficial esophageal disease (metaplasia, dysplasia, intramucosal cancer) in clinically applicable time scales.
authors.affiliation: Biophotonics Research Unit, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom; Department of Esophagogastric Surgery, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom.
authors.forename: L Max
authors.initials: LM
authors.lastname: Almond
authors.affiliation: Biophotonics Research Unit, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom.
authors.forename: Jo
authors.initials: J
authors.lastname: Hutchings
authors.affiliation: Biophotonics Research Unit, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom.
authors.forename: Gavin
authors.initials: G
authors.lastname: Lloyd
authors.affiliation: Biophotonics Research Unit, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom; Department of Esophagogastric Surgery, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom.
authors.forename: Hugh
authors.initials: H
authors.lastname: Barr
authors.affiliation: Department of Histopathology, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom.
authors.forename: Neil
authors.initials: N
authors.lastname: Shepherd
authors.affiliation: Interface Analysis Centre, University of Bristol, Bristol, United Kingdom.
authors.forename: John
authors.initials: J
authors.lastname: Day
authors.affiliation: Interface Analysis Centre, University of Bristol, Bristol, United Kingdom.
authors.forename: Oliver
authors.initials: O
authors.lastname: Stevens
authors.affiliation: Department of Histopathology, Warwick Hospital, Warwick, United Kingdom.
authors.forename: Scott
authors.initials: S
authors.lastname: Sanders
authors.affiliation: Department of Esophagogastric Surgery, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom; Department of Upper Gastrointestinal Surgery, Worcestershire Hospitals NHS Trust, Worcester, United Kingdom.
authors.forename: Martin
authors.initials: M
authors.lastname: Wadley
authors.affiliation: Department of Physics, Exeter University, Exeter, United Kingdom.
authors.forename: Nick
authors.initials: N
authors.lastname: Stone
authors.affiliation: Biophotonics Research Unit, Gloucestershire Hospitals NHS Foundation Trust, Gloucester, United Kingdom.
authors.forename: Catherine
authors.initials: C
authors.lastname: Kendall
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry* / Q000473:pathology*; D001471:Barrett Esophagus / Q000473:pathology*; D001706:Biopsy; D004938:Esophageal Neoplasms / Q000737:chemistry* / Q000473:pathology*; D016629:Esophagectomy; D004945:Esophagoscopy; D004947:Esophagus / Q000737:chemistry / Q000473:pathology*; D006801:Humans; D008679:Metaplasia / Q000473:pathology; D062048:Narrow Band Imaging; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman
keywords: ER; ERS; HGD; IM; LGD; NBI; NDBE; PC; RS; Raman spectroscopy; WLE; endoscopic Raman spectroscopy; endoscopic resection; high-grade dysplasia; intestinal metaplasia; low-grade dysplasia; narrow-band imaging; nondysplastic Barrett's esophagus; principal component; white light endoscopy