title: Normalized autofluorescence imaging diagnostics in upper GI tract: a new method to improve specificity in neoplasia detection.
abstract: OBJECTIVE
  This study was performed to improve the autofluorescence imaging (AFI) in the upper GI tract by applying a new method of normalized autofluorescence (NAFI) obtained via tri-modal imaging.
  
  
  OBJECTIVE
  NAFI may provide lower false positive rate to achieve ultimately better specificity at acceptable sensitivity.
  
  
  METHODS
  This is a prospective, controlled single-centre study. 18 patients with suspected esophagus or stomach cancer undergoing esophagogastroduodenoscopy (EGD) were enrolled between February and May 2010. After endoscopy each patient was assigned into one of two groups: (1) non-cancer, including inflammation; (2) cancer group. EGDs were performed using video white light endoscopy, followed by AFI/NAFI. The targeted biopsy samples were taken from the abnormal areas as well as from adjacent mucosa. NAFI was compared versus AFI for cancer diagnostics in terms of specificity and sensitivity.
  
  
  RESULTS
  NAFI detected all neoplastic lesions. WLE or NBI detected no additional neoplasia. The AFI displayed mucosal inflammation and carcinomas of esophagus and stomach as dark red color, the normal mucosa background was displayed as light green. The NAFI didn't differentiate inflamed tissue from normal in majority of cases, but in tumorous mucosa, the cancer areas were detected precisely. AFI shows 100% sensitivity but 50% specificity which correlates with previous literature data. On the other hand, NAFI demonstrated lower sensitivity (88%) but higher specificity compared to AFI (69%).
  
  
  CONCLUSIONS
  Measuring the NAFI instead of the AFI was found improving the specificity of cancer diagnosis. Use of fiber-optic endoscopes to analyze AFI and possible endoscopic and histological sampling error are the main potential limitations of this method.
authors.affiliation: Department of Medicine 1, University of Erlangen-Nuremberg Ulmenweg 18, D-91054 Erlangen, Germany.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Krauss
authors.forename: Abbas
authors.initials: A
authors.lastname: Agaimy
authors.forename: Alexandre
authors.initials: A
authors.lastname: Douplik
authors.forename: Heinz
authors.initials: H
authors.lastname: Albrecht
authors.forename: Helmut
authors.initials: H
authors.lastname: Neumann
authors.forename: Arndt
authors.initials: A
authors.lastname: Hartmann
authors.forename: Ralf
authors.initials: R
authors.lastname: Hohenstein
authors.forename: Martin
authors.initials: M
authors.lastname: Raithel
authors.forename: Eckhart G
authors.initials: EG
authors.lastname: Hahn
authors.forename: Markus F
authors.initials: MF
authors.lastname: Neurath
authors.forename: Jonas
authors.initials: J
authors.lastname: Mudter
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000368:Aged; D001706:Biopsy; D018279:Carcinoma, Signet Ring Cell / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D020776:Endoscopes, Gastrointestinal; D016145:Endoscopy, Digestive System / Q000295:instrumentation / Q000379:methods*; D004938:Esophageal Neoplasms / Q000473:pathology*; D004947:Esophagus / Q000473:pathology; D005336:Fiber Optic Technology; D005753:Gastric Mucosa / Q000473:pathology; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D061848:Optical Imaging / Q000295:instrumentation / Q000379:methods*; D011230:Precancerous Conditions / Q000473:pathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000473:pathology*; D014741:Video Recording
keywords: Autofluorescence imaging; NAFI; cancer diagnostic; endoscopic tri-modal imaging; esophagogastroduodenoscopy