title: Time-resolved autofluorescence spectroscopy for classifying normal and premalignant oral tissues.
abstract: OBJECTIVE
  Time-resolved autofluorescence spectroscopy has been used for effectively distinguishing normal tissues from precancers and cancers in various organs. The aim of this study was to find out the possibility of using time-resolved autofluorescence spectroscopy to differentiate normal oral mucosa (NOM) from oral premalignant lesions including verrucous hyperplasia (VH), epithelial hyperplasia (EH), and epithelial dysplasia (ED).
  
  
  METHODS
  Time-resolved autofluorescence spectra at 633 nm under 410-nm excitation were recorded for 15 VH, 9 EH, 14 ED, and 38 NOM samples. The two-component lifetimes of the obtained curves were calculated, and a Fisher's discriminant analysis (FDA) was employed for distinguishing these tissue samples.
  
  
  RESULTS
  After two-component lifetimes for all samples being calculated, a two-dimensional scatter plot was developed, in which 76 oral tissue samples were separated into three groups by FDA. With a leave-one-out method, the FDA algorithm gave an accuracy rate of 93% for ED, of 75% for VH and EH, and of 100% for NOM samples. In addition, all oral premalignant lesions (including VH, EH, and ED) could be distinguished from NOM samples by this FDA algorithm.
  
  
  CONCLUSIONS
  We conclude that time-resolved autofluorescence spectroscopy at 633 nm under 410-nm excitation, based on two-component lifetime calculation and FDA, is a very sensitive technique for in vivo diagnosis of oral premalignant lesions. .
authors.affiliation: Department of Dentistry, National Taiwan University Hospital, Taiwan.
authors.forename: Hsin-Ming
authors.initials: HM
authors.lastname: Chen
authors.forename: Chun-Pin
authors.initials: CP
authors.lastname: Chiang
authors.forename: Chun
authors.initials: C
authors.lastname: You
authors.forename: Tzu-Chien
authors.initials: TC
authors.lastname: Hsiao
authors.forename: Chih-Yu
authors.initials: CY
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology*; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000473:pathology; D013050:Spectrometry, Fluorescence / Q000379:methods*